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Diffstat (limited to 'src/tools/mdnssd/uDNS.c')
| -rwxr-xr-x | src/tools/mdnssd/uDNS.c | 4927 |
1 files changed, 0 insertions, 4927 deletions
diff --git a/src/tools/mdnssd/uDNS.c b/src/tools/mdnssd/uDNS.c deleted file mode 100755 index 57cfc1a689e..00000000000 --- a/src/tools/mdnssd/uDNS.c +++ /dev/null @@ -1,4927 +0,0 @@ -/* -*- Mode: C; tab-width: 4 -*- - * - * Copyright (c) 2002-2006 Apple Computer, Inc. All rights reserved. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - - * To Do: - * Elimate all mDNSPlatformMemAllocate/mDNSPlatformMemFree from this code -- the core code - * is supposed to be malloc-free so that it runs in constant memory determined at compile-time. - * Any dynamic run-time requirements should be handled by the platform layer below or client layer above - */ - -#if APPLE_OSX_mDNSResponder -#include <TargetConditionals.h> -#endif -#include "uDNS.h" - -#if(defined(_MSC_VER)) - // Disable "assignment within conditional expression". - // Other compilers understand the convention that if you place the assignment expression within an extra pair - // of parentheses, this signals to the compiler that you really intended an assignment and no warning is necessary. - // The Microsoft compiler doesn't understand this convention, so in the absense of any other way to signal - // to the compiler that the assignment is intentional, we have to just turn this warning off completely. - #pragma warning(disable:4706) -#endif - -// For domain enumeration and automatic browsing -// This is the user's DNS search list. -// In each of these domains we search for our special pointer records (lb._dns-sd._udp.<domain>, etc.) -// to discover recommended domains for domain enumeration (browse, default browse, registration, -// default registration) and possibly one or more recommended automatic browsing domains. -mDNSexport SearchListElem *SearchList = mDNSNULL; - -// The value can be set to true by the Platform code e.g., MacOSX uses the plist mechanism -mDNSBool StrictUnicastOrdering = mDNSfalse; - -// We keep track of the number of unicast DNS servers and log a message when we exceed 64. -// Currently the unicast queries maintain a 64 bit map to track the valid DNS servers for that -// question. Bit position is the index into the DNS server list. This is done so to try all -// the servers exactly once before giving up. If we could allocate memory in the core, then -// arbitrary limitation of 64 DNSServers can be removed. -mDNSu8 NumUnicastDNSServers = 0; -#define MAX_UNICAST_DNS_SERVERS 64 - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - General Utility Functions -#endif - -// set retry timestamp for record with exponential backoff -mDNSlocal void SetRecordRetry(mDNS *const m, AuthRecord *rr, mDNSu32 random) - { - rr->LastAPTime = m->timenow; - - if (rr->expire && rr->refreshCount < MAX_UPDATE_REFRESH_COUNT) - { - mDNSs32 remaining = rr->expire - m->timenow; - rr->refreshCount++; - if (remaining > MIN_UPDATE_REFRESH_TIME) - { - // Refresh at 70% + random (currently it is 0 to 10%) - rr->ThisAPInterval = 7 * (remaining/10) + (random ? random : mDNSRandom(remaining/10)); - // Don't update more often than 5 minutes - if (rr->ThisAPInterval < MIN_UPDATE_REFRESH_TIME) - rr->ThisAPInterval = MIN_UPDATE_REFRESH_TIME; - LogInfo("SetRecordRetry refresh in %d of %d for %s", - rr->ThisAPInterval/mDNSPlatformOneSecond, (rr->expire - m->timenow)/mDNSPlatformOneSecond, ARDisplayString(m, rr)); - } - else - { - rr->ThisAPInterval = MIN_UPDATE_REFRESH_TIME; - LogInfo("SetRecordRetry clamping to min refresh in %d of %d for %s", - rr->ThisAPInterval/mDNSPlatformOneSecond, (rr->expire - m->timenow)/mDNSPlatformOneSecond, ARDisplayString(m, rr)); - } - return; - } - - rr->expire = 0; - - rr->ThisAPInterval = rr->ThisAPInterval * QuestionIntervalStep; // Same Retry logic as Unicast Queries - if (rr->ThisAPInterval < INIT_RECORD_REG_INTERVAL) - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - if (rr->ThisAPInterval > MAX_RECORD_REG_INTERVAL) - rr->ThisAPInterval = MAX_RECORD_REG_INTERVAL; - - LogInfo("SetRecordRetry retry in %d ms for %s", rr->ThisAPInterval, ARDisplayString(m, rr)); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Name Server List Management -#endif - -mDNSexport DNSServer *mDNS_AddDNSServer(mDNS *const m, const domainname *d, const mDNSInterfaceID interface, const mDNSAddr *addr, const mDNSIPPort port, mDNSBool scoped, mDNSu32 timeout, mDNSBool cellIntf) - { - DNSServer **p = &m->DNSServers; - DNSServer *tmp = mDNSNULL; - - if ((NumUnicastDNSServers + 1) > MAX_UNICAST_DNS_SERVERS) - { - LogMsg("mDNS_AddDNSServer: DNS server limit of %d reached, not adding this server", MAX_UNICAST_DNS_SERVERS); - return mDNSNULL; - } - - if (!d) d = (const domainname *)""; - - LogInfo("mDNS_AddDNSServer: Adding %#a for %##s, InterfaceID %p, scoped %d", addr, d->c, interface, scoped); - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("mDNS_AddDNSServer: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - while (*p) // Check if we already have this {interface,address,port,domain} tuple registered - { - if ((*p)->scoped == scoped && (*p)->interface == interface && (*p)->teststate != DNSServer_Disabled && - mDNSSameAddress(&(*p)->addr, addr) && mDNSSameIPPort((*p)->port, port) && SameDomainName(&(*p)->domain, d)) - { - if (!((*p)->flags & DNSServer_FlagDelete)) debugf("Note: DNS Server %#a:%d for domain %##s (%p) registered more than once", addr, mDNSVal16(port), d->c, interface); - (*p)->flags &= ~DNSServer_FlagDelete; - tmp = *p; - *p = tmp->next; - tmp->next = mDNSNULL; - } - else - p=&(*p)->next; - } - - if (tmp) *p = tmp; // move to end of list, to ensure ordering from platform layer - else - { - // allocate, add to list - *p = mDNSPlatformMemAllocate(sizeof(**p)); - if (!*p) LogMsg("Error: mDNS_AddDNSServer - malloc"); - else - { - NumUnicastDNSServers++; - (*p)->scoped = scoped; - (*p)->interface = interface; - (*p)->addr = *addr; - (*p)->port = port; - (*p)->flags = DNSServer_FlagNew; - (*p)->teststate = /* DNSServer_Untested */ DNSServer_Passed; - (*p)->lasttest = m->timenow - INIT_UCAST_POLL_INTERVAL; - (*p)->timeout = timeout; - (*p)->cellIntf = cellIntf; - AssignDomainName(&(*p)->domain, d); - (*p)->next = mDNSNULL; - } - } - (*p)->penaltyTime = 0; - return(*p); - } - -// PenalizeDNSServer is called when the number of queries to the unicast -// DNS server exceeds MAX_UCAST_UNANSWERED_QUERIES or when we receive an -// error e.g., SERV_FAIL from DNS server. -mDNSexport void PenalizeDNSServer(mDNS *const m, DNSQuestion *q) - { - DNSServer *new; - DNSServer *orig = q->qDNSServer; - - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("PenalizeDNSServer: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - // This should never happen. Whenever we change DNS server, we change the ID on the question and hence - // we should never accept a response after we penalize a DNS server e.g., send two queries, no response, - // penalize DNS server and no new servers to pick for the question and hence qDNSServer is NULL. If we - // receive a response now, the DNS server can be NULL. But we won't because the ID already has been - // changed. - if (!q->qDNSServer) - { - LogMsg("PenalizeDNSServer: ERROR!! Null DNS server for %##s (%s) %d", q->qname.c, DNSTypeName(q->qtype), q->unansweredQueries); - goto end; - } - - LogInfo("PenalizeDNSServer: Penalizing DNS server %#a:%d question (%##s) for question %p %##s (%s) SuppressUnusable %d", - &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), q->qDNSServer->domain.c, q, q->qname.c, DNSTypeName(q->qtype), - q->SuppressUnusable); - - // If strict ordering of unicast servers needs to be preserved, we just lookup - // the next best match server below - // - // If strict ordering is not required which is the default behavior, we penalize the server - // for DNSSERVER_PENALTY_TIME. We may also use additional logic e.g., don't penalize for PTR - // in the future. - - if (!StrictUnicastOrdering) - { - LogInfo("PenalizeDNSServer: Strict Unicast Ordering is FALSE"); - // We penalize the server so that new queries don't pick this server for DNSSERVER_PENALTY_TIME - // XXX Include other logic here to see if this server should really be penalized - // - if (q->qtype == kDNSType_PTR) - { - LogInfo("PenalizeDNSServer: Not Penalizing PTR question"); - } - else - { - LogInfo("PenalizeDNSServer: Penalizing question type %d", q->qtype); - q->qDNSServer->penaltyTime = NonZeroTime(m->timenow + DNSSERVER_PENALTY_TIME); - } - } - else - { - LogInfo("PenalizeDNSServer: Strict Unicast Ordering is TRUE"); - } - -end: - new = GetServerForQuestion(m, q); - - - if (new == orig) - { - if (new) - LogMsg("PenalizeDNSServer: ERROR!! GetServerForQuestion returned the same server %#a:%d", &new->addr, - mDNSVal16(new->port)); - else - LogMsg("PenalizeDNSServer: ERROR!! GetServerForQuestion returned the same server NULL"); - q->ThisQInterval = 0; // Inactivate this question so that we dont bombard the network - } - else - { - // The new DNSServer is set in DNSServerChangeForQuestion - DNSServerChangeForQuestion(m, q, new); - - if (new) - { - LogInfo("PenalizeDNSServer: Server for %##s (%s) changed to %#a:%d (%##s)", - q->qname.c, DNSTypeName(q->qtype), &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), q->qDNSServer->domain.c); - // We want to try the next server immediately. As the question may already have backed off, reset - // the interval. We do this only the first time when we try all the DNS servers. Once we reached the end of - // list and retrying all the servers again e.g., at least one server failed to respond in the previous try, we - // use the normal backoff which is done in uDNS_CheckCurrentQuestion when we send the packet out. - if (!q->triedAllServersOnce) - { - q->ThisQInterval = InitialQuestionInterval; - q->LastQTime = m->timenow - q->ThisQInterval; - SetNextQueryTime(m, q); - } - } - else - { - // We don't have any more DNS servers for this question. If some server in the list did not return - // any response, we need to keep retrying till we get a response. uDNS_CheckCurrentQuestion handles - // this case. - // - // If all servers responded with a negative response, We need to do two things. First, generate a - // negative response so that applications get a reply. We also need to reinitialize the DNS servers - // so that when the cache expires, we can restart the query. - // - // Negative response may be generated in two ways. - // - // 1. AnswerQuestionForDNSServerChanges (called from DNSServerChangedForQuestion) might find some - // cache entries and answer this question. - // 2. uDNS_CheckCurrentQuestion will create a new cache entry and answer this question - // - // For (1), it might be okay to reinitialize the DNS servers here. But for (2), we can't do it here - // because uDNS_CheckCurrentQuestion will try resending the queries. Hence, to be consistent, we - // defer reintializing the DNS servers up until generating a negative cache response. - // - // Be careful not to touch the ThisQInterval here. For a normal question, when we answer the question - // in AnswerCurrentQuestionWithResourceRecord will set ThisQInterval to MaxQuestionInterval and hence - // the next query will not happen until cache expiry. If it is a long lived question, - // AnswerCurrentQuestionWithResourceRecord will not set it to MaxQuestionInterval. In that case, - // we want the normal backoff to work. - LogInfo("PenalizeDNSServer: Server for %p, %##s (%s) changed to NULL, Interval %d", q, q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); - } - q->unansweredQueries = 0; - - } - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - authorization management -#endif - -mDNSlocal DomainAuthInfo *GetAuthInfoForName_direct(mDNS *m, const domainname *const name) - { - const domainname *n = name; - while (n->c[0]) - { - DomainAuthInfo *ptr; - for (ptr = m->AuthInfoList; ptr; ptr = ptr->next) - if (SameDomainName(&ptr->domain, n)) - { - debugf("GetAuthInfoForName %##s Matched %##s Key name %##s", name->c, ptr->domain.c, ptr->keyname.c); - return(ptr); - } - n = (const domainname *)(n->c + 1 + n->c[0]); - } - //LogInfo("GetAuthInfoForName none found for %##s", name->c); - return mDNSNULL; - } - -// MUST be called with lock held -mDNSexport DomainAuthInfo *GetAuthInfoForName_internal(mDNS *m, const domainname *const name) - { - DomainAuthInfo **p = &m->AuthInfoList; - - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("GetAuthInfoForName_internal: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - // First purge any dead keys from the list - while (*p) - { - if ((*p)->deltime && m->timenow - (*p)->deltime >= 0 && AutoTunnelUnregistered(*p)) - { - DNSQuestion *q; - DomainAuthInfo *info = *p; - LogInfo("GetAuthInfoForName_internal deleting expired key %##s %##s", info->domain.c, info->keyname.c); - *p = info->next; // Cut DomainAuthInfo from list *before* scanning our question list updating AuthInfo pointers - for (q = m->Questions; q; q=q->next) - if (q->AuthInfo == info) - { - q->AuthInfo = GetAuthInfoForName_direct(m, &q->qname); - debugf("GetAuthInfoForName_internal updated q->AuthInfo from %##s to %##s for %##s (%s)", - info->domain.c, q->AuthInfo ? q->AuthInfo->domain.c : mDNSNULL, q->qname.c, DNSTypeName(q->qtype)); - } - - // Probably not essential, but just to be safe, zero out the secret key data - // so we don't leave it hanging around in memory - // (where it could potentially get exposed via some other bug) - mDNSPlatformMemZero(info, sizeof(*info)); - mDNSPlatformMemFree(info); - } - else - p = &(*p)->next; - } - - return(GetAuthInfoForName_direct(m, name)); - } - -mDNSexport DomainAuthInfo *GetAuthInfoForName(mDNS *m, const domainname *const name) - { - DomainAuthInfo *d; - mDNS_Lock(m); - d = GetAuthInfoForName_internal(m, name); - mDNS_Unlock(m); - return(d); - } - -// MUST be called with the lock held -mDNSexport mStatus mDNS_SetSecretForDomain(mDNS *m, DomainAuthInfo *info, - const domainname *domain, const domainname *keyname, const char *b64keydata, const domainname *hostname, mDNSIPPort *port, const char *autoTunnelPrefix) - { - DNSQuestion *q; - DomainAuthInfo **p = &m->AuthInfoList; - if (!info || !b64keydata) { LogMsg("mDNS_SetSecretForDomain: ERROR: info %p b64keydata %p", info, b64keydata); return(mStatus_BadParamErr); } - - LogInfo("mDNS_SetSecretForDomain: domain %##s key %##s%s%s", domain->c, keyname->c, autoTunnelPrefix ? " prefix " : "", autoTunnelPrefix ? autoTunnelPrefix : ""); - - info->AutoTunnel = autoTunnelPrefix; - AssignDomainName(&info->domain, domain); - AssignDomainName(&info->keyname, keyname); - if (hostname) - AssignDomainName(&info->hostname, hostname); - else - info->hostname.c[0] = 0; - if (port) - info->port = *port; - else - info->port = zeroIPPort; - mDNS_snprintf(info->b64keydata, sizeof(info->b64keydata), "%s", b64keydata); - - if (DNSDigest_ConstructHMACKeyfromBase64(info, b64keydata) < 0) - { - LogMsg("mDNS_SetSecretForDomain: ERROR: Could not convert shared secret from base64: domain %##s key %##s %s", domain->c, keyname->c, mDNS_LoggingEnabled ? b64keydata : ""); - return(mStatus_BadParamErr); - } - - // Don't clear deltime until after we've ascertained that b64keydata is valid - info->deltime = 0; - - while (*p && (*p) != info) p=&(*p)->next; - if (*p) {LogInfo("mDNS_SetSecretForDomain: Domain %##s Already in list", (*p)->domain.c); return(mStatus_AlreadyRegistered);} - - // Caution: Only zero AutoTunnelHostRecord.namestorage and AutoTunnelNAT.clientContext AFTER we've determined that this is a NEW DomainAuthInfo - // being added to the list. Otherwise we risk smashing our AutoTunnel host records and NATOperation that are already active and in use. - info->AutoTunnelHostRecord.resrec.RecordType = kDNSRecordTypeUnregistered; - info->AutoTunnelHostRecord.namestorage.c[0] = 0; - info->AutoTunnelTarget .resrec.RecordType = kDNSRecordTypeUnregistered; - info->AutoTunnelDeviceInfo.resrec.RecordType = kDNSRecordTypeUnregistered; - info->AutoTunnelService .resrec.RecordType = kDNSRecordTypeUnregistered; - info->AutoTunnel6Record .resrec.RecordType = kDNSRecordTypeUnregistered; - info->AutoTunnelNAT.clientContext = mDNSNULL; - info->next = mDNSNULL; - *p = info; - - // Check to see if adding this new DomainAuthInfo has changed the credentials for any of our questions - for (q = m->Questions; q; q=q->next) - { - DomainAuthInfo *newinfo = GetAuthInfoForQuestion(m, q); - if (q->AuthInfo != newinfo) - { - debugf("mDNS_SetSecretForDomain updating q->AuthInfo from %##s to %##s for %##s (%s)", - q->AuthInfo ? q->AuthInfo->domain.c : mDNSNULL, - newinfo ? newinfo ->domain.c : mDNSNULL, q->qname.c, DNSTypeName(q->qtype)); - q->AuthInfo = newinfo; - } - } - - return(mStatus_NoError); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - NAT Traversal -#endif - -mDNSlocal mStatus uDNS_SendNATMsg(mDNS *m, NATTraversalInfo *info) - { - mStatus err = mStatus_NoError; - - // send msg if we have a router and it is a private address - if (!mDNSIPv4AddressIsZero(m->Router.ip.v4) && mDNSv4AddrIsRFC1918(&m->Router.ip.v4)) - { - union { NATAddrRequest NATAddrReq; NATPortMapRequest NATPortReq; } u = { { NATMAP_VERS, NATOp_AddrRequest } } ; - const mDNSu8 *end = (mDNSu8 *)&u + sizeof(NATAddrRequest); - - if (info) // For NATOp_MapUDP and NATOp_MapTCP, fill in additional fields - { - mDNSu8 *p = (mDNSu8 *)&u.NATPortReq.NATReq_lease; - u.NATPortReq.opcode = info->Protocol; - u.NATPortReq.unused = zeroID; - u.NATPortReq.intport = info->IntPort; - u.NATPortReq.extport = info->RequestedPort; - p[0] = (mDNSu8)((info->NATLease >> 24) & 0xFF); - p[1] = (mDNSu8)((info->NATLease >> 16) & 0xFF); - p[2] = (mDNSu8)((info->NATLease >> 8) & 0xFF); - p[3] = (mDNSu8)( info->NATLease & 0xFF); - end = (mDNSu8 *)&u + sizeof(NATPortMapRequest); - } - - err = mDNSPlatformSendUDP(m, (mDNSu8 *)&u, end, 0, mDNSNULL, &m->Router, NATPMPPort); - -#ifdef _LEGACY_NAT_TRAVERSAL_ - if (mDNSIPPortIsZero(m->UPnPRouterPort) || mDNSIPPortIsZero(m->UPnPSOAPPort)) LNT_SendDiscoveryMsg(m); - else if (info) err = LNT_MapPort(m, info); - else err = LNT_GetExternalAddress(m); -#endif // _LEGACY_NAT_TRAVERSAL_ - } - return(err); - } - -mDNSexport void RecreateNATMappings(mDNS *const m) - { - NATTraversalInfo *n; - for (n = m->NATTraversals; n; n=n->next) - { - n->ExpiryTime = 0; // Mark this mapping as expired - n->retryInterval = NATMAP_INIT_RETRY; - n->retryPortMap = m->timenow; -#ifdef _LEGACY_NAT_TRAVERSAL_ - if (n->tcpInfo.sock) { mDNSPlatformTCPCloseConnection(n->tcpInfo.sock); n->tcpInfo.sock = mDNSNULL; } -#endif // _LEGACY_NAT_TRAVERSAL_ - } - - m->NextScheduledNATOp = m->timenow; // Need to send packets immediately - } - -mDNSexport void natTraversalHandleAddressReply(mDNS *const m, mDNSu16 err, mDNSv4Addr ExtAddr) - { - static mDNSu16 last_err = 0; - - if (err) - { - if (err != last_err) LogMsg("Error getting external address %d", err); - ExtAddr = zerov4Addr; - } - else - { - LogInfo("Received external IP address %.4a from NAT", &ExtAddr); - if (mDNSv4AddrIsRFC1918(&ExtAddr)) - LogMsg("Double NAT (external NAT gateway address %.4a is also a private RFC 1918 address)", &ExtAddr); - if (mDNSIPv4AddressIsZero(ExtAddr)) - err = NATErr_NetFail; // fake error to handle routers that pathologically report success with the zero address - } - - if (!mDNSSameIPv4Address(m->ExternalAddress, ExtAddr)) - { - m->ExternalAddress = ExtAddr; - RecreateNATMappings(m); // Also sets NextScheduledNATOp for us - } - - if (!err) // Success, back-off to maximum interval - m->retryIntervalGetAddr = NATMAP_MAX_RETRY_INTERVAL; - else if (!last_err) // Failure after success, retry quickly (then back-off exponentially) - m->retryIntervalGetAddr = NATMAP_INIT_RETRY; - // else back-off normally in case of pathological failures - - m->retryGetAddr = m->timenow + m->retryIntervalGetAddr; - if (m->NextScheduledNATOp - m->retryIntervalGetAddr > 0) - m->NextScheduledNATOp = m->retryIntervalGetAddr; - - last_err = err; - } - -// Both places that call NATSetNextRenewalTime() update m->NextScheduledNATOp correctly afterwards -mDNSlocal void NATSetNextRenewalTime(mDNS *const m, NATTraversalInfo *n) - { - n->retryInterval = (n->ExpiryTime - m->timenow)/2; - if (n->retryInterval < NATMAP_MIN_RETRY_INTERVAL) // Min retry interval is 2 seconds - n->retryInterval = NATMAP_MIN_RETRY_INTERVAL; - n->retryPortMap = m->timenow + n->retryInterval; - } - -// Note: When called from handleLNTPortMappingResponse() only pkt->err, pkt->extport and pkt->NATRep_lease fields are filled in -mDNSexport void natTraversalHandlePortMapReply(mDNS *const m, NATTraversalInfo *n, const mDNSInterfaceID InterfaceID, mDNSu16 err, mDNSIPPort extport, mDNSu32 lease) - { - const char *prot = n->Protocol == NATOp_MapUDP ? "UDP" : n->Protocol == NATOp_MapTCP ? "TCP" : "?"; - (void)prot; - n->NewResult = err; - if (err || lease == 0 || mDNSIPPortIsZero(extport)) - { - LogInfo("natTraversalHandlePortMapReply: %p Response %s Port %5d External Port %5d lease %d error %d", - n, prot, mDNSVal16(n->IntPort), mDNSVal16(extport), lease, err); - n->retryInterval = NATMAP_MAX_RETRY_INTERVAL; - n->retryPortMap = m->timenow + NATMAP_MAX_RETRY_INTERVAL; - // No need to set m->NextScheduledNATOp here, since we're only ever extending the m->retryPortMap time - if (err == NATErr_Refused) n->NewResult = mStatus_NATPortMappingDisabled; - else if (err > NATErr_None && err <= NATErr_Opcode) n->NewResult = mStatus_NATPortMappingUnsupported; - } - else - { - if (lease > 999999999UL / mDNSPlatformOneSecond) - lease = 999999999UL / mDNSPlatformOneSecond; - n->ExpiryTime = NonZeroTime(m->timenow + lease * mDNSPlatformOneSecond); - - if (!mDNSSameIPPort(n->RequestedPort, extport)) - LogInfo("natTraversalHandlePortMapReply: %p Response %s Port %5d External Port %5d changed to %5d", - n, prot, mDNSVal16(n->IntPort), mDNSVal16(n->RequestedPort), mDNSVal16(extport)); - - n->InterfaceID = InterfaceID; - n->RequestedPort = extport; - - LogInfo("natTraversalHandlePortMapReply: %p Response %s Port %5d External Port %5d lease %d", - n, prot, mDNSVal16(n->IntPort), mDNSVal16(extport), lease); - - NATSetNextRenewalTime(m, n); // Got our port mapping; now set timer to renew it at halfway point - m->NextScheduledNATOp = m->timenow; // May need to invoke client callback immediately - } - } - -// Must be called with the mDNS_Lock held -mDNSexport mStatus mDNS_StartNATOperation_internal(mDNS *const m, NATTraversalInfo *traversal) - { - NATTraversalInfo **n; - - LogInfo("mDNS_StartNATOperation_internal %p Protocol %d IntPort %d RequestedPort %d NATLease %d", traversal, - traversal->Protocol, mDNSVal16(traversal->IntPort), mDNSVal16(traversal->RequestedPort), traversal->NATLease); - - // Note: It important that new traversal requests are appended at the *end* of the list, not prepended at the start - for (n = &m->NATTraversals; *n; n=&(*n)->next) - { - if (traversal == *n) - { - LogMsg("Error! Tried to add a NAT traversal that's already in the active list: request %p Prot %d Int %d TTL %d", - traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease); - #if ForceAlerts - *(long*)0 = 0; - #endif - return(mStatus_AlreadyRegistered); - } - if (traversal->Protocol && traversal->Protocol == (*n)->Protocol && mDNSSameIPPort(traversal->IntPort, (*n)->IntPort) && - !mDNSSameIPPort(traversal->IntPort, SSHPort)) - LogMsg("Warning: Created port mapping request %p Prot %d Int %d TTL %d " - "duplicates existing port mapping request %p Prot %d Int %d TTL %d", - traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease, - *n, (*n) ->Protocol, mDNSVal16((*n) ->IntPort), (*n) ->NATLease); - } - - // Initialize necessary fields - traversal->next = mDNSNULL; - traversal->ExpiryTime = 0; - traversal->retryInterval = NATMAP_INIT_RETRY; - traversal->retryPortMap = m->timenow; - traversal->NewResult = mStatus_NoError; - traversal->ExternalAddress = onesIPv4Addr; - traversal->ExternalPort = zeroIPPort; - traversal->Lifetime = 0; - traversal->Result = mStatus_NoError; - - // set default lease if necessary - if (!traversal->NATLease) traversal->NATLease = NATMAP_DEFAULT_LEASE; - -#ifdef _LEGACY_NAT_TRAVERSAL_ - mDNSPlatformMemZero(&traversal->tcpInfo, sizeof(traversal->tcpInfo)); -#endif // _LEGACY_NAT_TRAVERSAL_ - - if (!m->NATTraversals) // If this is our first NAT request, kick off an address request too - { - m->retryGetAddr = m->timenow; - m->retryIntervalGetAddr = NATMAP_INIT_RETRY; - } - - m->NextScheduledNATOp = m->timenow; // This will always trigger sending the packet ASAP, and generate client callback if necessary - - *n = traversal; // Append new NATTraversalInfo to the end of our list - - return(mStatus_NoError); - } - -// Must be called with the mDNS_Lock held -mDNSexport mStatus mDNS_StopNATOperation_internal(mDNS *m, NATTraversalInfo *traversal) - { - mDNSBool unmap = mDNStrue; - NATTraversalInfo *p; - NATTraversalInfo **ptr = &m->NATTraversals; - - while (*ptr && *ptr != traversal) ptr=&(*ptr)->next; - if (*ptr) *ptr = (*ptr)->next; // If we found it, cut this NATTraversalInfo struct from our list - else - { - LogMsg("mDNS_StopNATOperation_internal: NATTraversalInfo %p not found in list", traversal); - return(mStatus_BadReferenceErr); - } - - LogInfo("mDNS_StopNATOperation_internal %p %d %d %d %d", traversal, - traversal->Protocol, mDNSVal16(traversal->IntPort), mDNSVal16(traversal->RequestedPort), traversal->NATLease); - - if (m->CurrentNATTraversal == traversal) - m->CurrentNATTraversal = m->CurrentNATTraversal->next; - - if (traversal->Protocol) - for (p = m->NATTraversals; p; p=p->next) - if (traversal->Protocol == p->Protocol && mDNSSameIPPort(traversal->IntPort, p->IntPort)) - { - if (!mDNSSameIPPort(traversal->IntPort, SSHPort)) - LogMsg("Warning: Removed port mapping request %p Prot %d Int %d TTL %d " - "duplicates existing port mapping request %p Prot %d Int %d TTL %d", - traversal, traversal->Protocol, mDNSVal16(traversal->IntPort), traversal->NATLease, - p, p ->Protocol, mDNSVal16(p ->IntPort), p ->NATLease); - unmap = mDNSfalse; - } - - if (traversal->ExpiryTime && unmap) - { - traversal->NATLease = 0; - traversal->retryInterval = 0; - uDNS_SendNATMsg(m, traversal); - } - - // Even if we DIDN'T make a successful UPnP mapping yet, we might still have a partially-open TCP connection we need to clean up - #ifdef _LEGACY_NAT_TRAVERSAL_ - { - mStatus err = LNT_UnmapPort(m, traversal); - if (err) LogMsg("Legacy NAT Traversal - unmap request failed with error %d", err); - } - #endif // _LEGACY_NAT_TRAVERSAL_ - - return(mStatus_NoError); - } - -mDNSexport mStatus mDNS_StartNATOperation(mDNS *const m, NATTraversalInfo *traversal) - { - mStatus status; - mDNS_Lock(m); - status = mDNS_StartNATOperation_internal(m, traversal); - mDNS_Unlock(m); - return(status); - } - -mDNSexport mStatus mDNS_StopNATOperation(mDNS *const m, NATTraversalInfo *traversal) - { - mStatus status; - mDNS_Lock(m); - status = mDNS_StopNATOperation_internal(m, traversal); - mDNS_Unlock(m); - return(status); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - Long-Lived Queries -#endif - -// Lock must be held -- otherwise m->timenow is undefined -mDNSlocal void StartLLQPolling(mDNS *const m, DNSQuestion *q) - { - debugf("StartLLQPolling: %##s", q->qname.c); - q->state = LLQ_Poll; - q->ThisQInterval = INIT_UCAST_POLL_INTERVAL; - // We want to send our poll query ASAP, but the "+ 1" is because if we set the time to now, - // we risk causing spurious "SendQueries didn't send all its queries" log messages - q->LastQTime = m->timenow - q->ThisQInterval + 1; - SetNextQueryTime(m, q); -#if APPLE_OSX_mDNSResponder - UpdateAutoTunnelDomainStatuses(m); -#endif - } - -mDNSlocal mDNSu8 *putLLQ(DNSMessage *const msg, mDNSu8 *ptr, const DNSQuestion *const question, const LLQOptData *const data) - { - AuthRecord rr; - ResourceRecord *opt = &rr.resrec; - rdataOPT *optRD; - - //!!!KRS when we implement multiple llqs per message, we'll need to memmove anything past the question section - ptr = putQuestion(msg, ptr, msg->data + AbsoluteMaxDNSMessageData, &question->qname, question->qtype, question->qclass); - if (!ptr) { LogMsg("ERROR: putLLQ - putQuestion"); return mDNSNULL; } - - // locate OptRR if it exists, set pointer to end - // !!!KRS implement me - - // format opt rr (fields not specified are zero-valued) - mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); - opt->rrclass = NormalMaxDNSMessageData; - opt->rdlength = sizeof(rdataOPT); // One option in this OPT record - opt->rdestimate = sizeof(rdataOPT); - - optRD = &rr.resrec.rdata->u.opt[0]; - optRD->opt = kDNSOpt_LLQ; - optRD->u.llq = *data; - ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.numAdditionals, opt, 0); - if (!ptr) { LogMsg("ERROR: putLLQ - PutResourceRecordTTLJumbo"); return mDNSNULL; } - - return ptr; - } - -// Normally we'd just request event packets be sent directly to m->LLQNAT.ExternalPort, except... -// with LLQs over TLS/TCP we're doing a weird thing where instead of requesting packets be sent to ExternalAddress:ExternalPort -// we're requesting that packets be sent to ExternalPort, but at the source address of our outgoing TCP connection. -// Normally, after going through the NAT gateway, the source address of our outgoing TCP connection is the same as ExternalAddress, -// so this is fine, except when the TCP connection ends up going over a VPN tunnel instead. -// To work around this, if we find that the source address for our TCP connection is not a private address, we tell the Dot Mac -// LLQ server to send events to us directly at port 5353 on that address, instead of at our mapped external NAT port. - -mDNSlocal mDNSu16 GetLLQEventPort(const mDNS *const m, const mDNSAddr *const dst) - { - mDNSAddr src; - mDNSPlatformSourceAddrForDest(&src, dst); - //LogMsg("GetLLQEventPort: src %#a for dst %#a (%d)", &src, dst, mDNSv4AddrIsRFC1918(&src.ip.v4) ? mDNSVal16(m->LLQNAT.ExternalPort) : 0); - return(mDNSv4AddrIsRFC1918(&src.ip.v4) ? mDNSVal16(m->LLQNAT.ExternalPort) : mDNSVal16(MulticastDNSPort)); - } - -// Normally called with llq set. -// May be called with llq NULL, when retransmitting a lost Challenge Response -mDNSlocal void sendChallengeResponse(mDNS *const m, DNSQuestion *const q, const LLQOptData *llq) - { - mDNSu8 *responsePtr = m->omsg.data; - LLQOptData llqBuf; - - if (q->tcp) { LogMsg("sendChallengeResponse: ERROR!!: question %##s (%s) tcp non-NULL", q->qname.c, DNSTypeName(q->qtype)); return; } - - if (PrivateQuery(q)) { LogMsg("sendChallengeResponse: ERROR!!: Private Query %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } - - if (q->ntries++ == kLLQ_MAX_TRIES) - { - LogMsg("sendChallengeResponse: %d failed attempts for LLQ %##s", kLLQ_MAX_TRIES, q->qname.c); - StartLLQPolling(m,q); - return; - } - - if (!llq) // Retransmission: need to make a new LLQOptData - { - llqBuf.vers = kLLQ_Vers; - llqBuf.llqOp = kLLQOp_Setup; - llqBuf.err = LLQErr_NoError; // Don't need to tell server UDP notification port when sending over UDP - llqBuf.id = q->id; - llqBuf.llqlease = q->ReqLease; - llq = &llqBuf; - } - - q->LastQTime = m->timenow; - q->ThisQInterval = q->tcp ? 0 : (kLLQ_INIT_RESEND * q->ntries * mDNSPlatformOneSecond); // If using TCP, don't need to retransmit - SetNextQueryTime(m, q); - - // To simulate loss of challenge response packet, uncomment line below - //if (q->ntries == 1) return; - - InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); - responsePtr = putLLQ(&m->omsg, responsePtr, q, llq); - if (responsePtr) - { - mStatus err = mDNSSendDNSMessage(m, &m->omsg, responsePtr, mDNSInterface_Any, q->LocalSocket, &q->servAddr, q->servPort, mDNSNULL, mDNSNULL); - if (err) { LogMsg("sendChallengeResponse: mDNSSendDNSMessage%s failed: %d", q->tcp ? " (TCP)" : "", err); } - } - else StartLLQPolling(m,q); - } - -mDNSlocal void SetLLQTimer(mDNS *const m, DNSQuestion *const q, const LLQOptData *const llq) - { - mDNSs32 lease = (mDNSs32)llq->llqlease * mDNSPlatformOneSecond; - q->ReqLease = llq->llqlease; - q->LastQTime = m->timenow; - q->expire = m->timenow + lease; - q->ThisQInterval = lease/2 + mDNSRandom(lease/10); - debugf("SetLLQTimer setting %##s (%s) to %d %d", q->qname.c, DNSTypeName(q->qtype), lease/mDNSPlatformOneSecond, q->ThisQInterval/mDNSPlatformOneSecond); - SetNextQueryTime(m, q); - } - -mDNSlocal void recvSetupResponse(mDNS *const m, mDNSu8 rcode, DNSQuestion *const q, const LLQOptData *const llq) - { - if (rcode && rcode != kDNSFlag1_RC_NXDomain) - { LogMsg("ERROR: recvSetupResponse %##s (%s) - rcode && rcode != kDNSFlag1_RC_NXDomain", q->qname.c, DNSTypeName(q->qtype)); return; } - - if (llq->llqOp != kLLQOp_Setup) - { LogMsg("ERROR: recvSetupResponse %##s (%s) - bad op %d", q->qname.c, DNSTypeName(q->qtype), llq->llqOp); return; } - - if (llq->vers != kLLQ_Vers) - { LogMsg("ERROR: recvSetupResponse %##s (%s) - bad vers %d", q->qname.c, DNSTypeName(q->qtype), llq->vers); return; } - - if (q->state == LLQ_InitialRequest) - { - //LogInfo("Got LLQ_InitialRequest"); - - if (llq->err) { LogMsg("recvSetupResponse - received llq->err %d from server", llq->err); StartLLQPolling(m,q); return; } - - if (q->ReqLease != llq->llqlease) - debugf("recvSetupResponse: requested lease %lu, granted lease %lu", q->ReqLease, llq->llqlease); - - // cache expiration in case we go to sleep before finishing setup - q->ReqLease = llq->llqlease; - q->expire = m->timenow + ((mDNSs32)llq->llqlease * mDNSPlatformOneSecond); - - // update state - q->state = LLQ_SecondaryRequest; - q->id = llq->id; - q->ntries = 0; // first attempt to send response - sendChallengeResponse(m, q, llq); - } - else if (q->state == LLQ_SecondaryRequest) - { - //LogInfo("Got LLQ_SecondaryRequest"); - - // Fix this immediately if not sooner. Copy the id from the LLQOptData into our DNSQuestion struct. This is only - // an issue for private LLQs, because we skip parts 2 and 3 of the handshake. This is related to a bigger - // problem of the current implementation of TCP LLQ setup: we're not handling state transitions correctly - // if the server sends back SERVFULL or STATIC. - if (PrivateQuery(q)) - { - LogInfo("Private LLQ_SecondaryRequest; copying id %08X%08X", llq->id.l[0], llq->id.l[1]); - q->id = llq->id; - } - - if (llq->err) { LogMsg("ERROR: recvSetupResponse %##s (%s) code %d from server", q->qname.c, DNSTypeName(q->qtype), llq->err); StartLLQPolling(m,q); return; } - if (!mDNSSameOpaque64(&q->id, &llq->id)) - { LogMsg("recvSetupResponse - ID changed. discarding"); return; } // this can happen rarely (on packet loss + reordering) - q->state = LLQ_Established; - q->ntries = 0; - SetLLQTimer(m, q, llq); -#if APPLE_OSX_mDNSResponder - UpdateAutoTunnelDomainStatuses(m); -#endif - } - } - -mDNSexport uDNS_LLQType uDNS_recvLLQResponse(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, - const mDNSAddr *const srcaddr, const mDNSIPPort srcport, DNSQuestion **matchQuestion) - { - DNSQuestion pktQ, *q; - if (msg->h.numQuestions && getQuestion(msg, msg->data, end, 0, &pktQ)) - { - const rdataOPT *opt = GetLLQOptData(m, msg, end); - - for (q = m->Questions; q; q = q->next) - { - if (!mDNSOpaque16IsZero(q->TargetQID) && q->LongLived && q->qtype == pktQ.qtype && q->qnamehash == pktQ.qnamehash && SameDomainName(&q->qname, &pktQ.qname)) - { - debugf("uDNS_recvLLQResponse found %##s (%s) %d %#a %#a %X %X %X %X %d", - q->qname.c, DNSTypeName(q->qtype), q->state, srcaddr, &q->servAddr, - opt ? opt->u.llq.id.l[0] : 0, opt ? opt->u.llq.id.l[1] : 0, q->id.l[0], q->id.l[1], opt ? opt->u.llq.llqOp : 0); - if (q->state == LLQ_Poll) debugf("uDNS_LLQ_Events: q->state == LLQ_Poll msg->h.id %d q->TargetQID %d", mDNSVal16(msg->h.id), mDNSVal16(q->TargetQID)); - if (q->state == LLQ_Poll && mDNSSameOpaque16(msg->h.id, q->TargetQID)) - { - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - - // Don't reset the state to IntialRequest as we may write that to the dynamic store - // and PrefPane might wrongly think that we are "Starting" instead of "Polling". If - // we are in polling state because of NAT-PMP disabled or DoubleNAT, next LLQNATCallback - // would kick us back to LLQInitialRequest. So, resetting the state here may not be useful. - // - // If we have a good NAT (neither NAT-PMP disabled nor Double-NAT), then we should not be - // possibly in polling state. To be safe, we want to retry from the start in that case - // as there may not be another LLQNATCallback - // - // NOTE: We can be in polling state if we cannot resolve the SOA record i.e, servAddr is set to - // all ones. In that case, we would set it in LLQ_InitialRequest as it overrides the NAT-PMP or - // Double-NAT state. - if (!mDNSAddressIsOnes(&q->servAddr) && !mDNSIPPortIsZero(m->LLQNAT.ExternalPort) && - !m->LLQNAT.Result) - { - debugf("uDNS_recvLLQResponse got poll response; moving to LLQ_InitialRequest for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - q->state = LLQ_InitialRequest; - } - q->servPort = zeroIPPort; // Clear servPort so that startLLQHandshake will retry the GetZoneData processing - q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry LLQ setup in approx 15 minutes - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - *matchQuestion = q; - return uDNS_LLQ_Entire; // uDNS_LLQ_Entire means flush stale records; assume a large effective TTL - } - // Note: In LLQ Event packets, the msg->h.id does not match our q->TargetQID, because in that case the msg->h.id nonce is selected by the server - else if (opt && q->state == LLQ_Established && opt->u.llq.llqOp == kLLQOp_Event && mDNSSameOpaque64(&opt->u.llq.id, &q->id)) - { - mDNSu8 *ackEnd; - //debugf("Sending LLQ ack for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - InitializeDNSMessage(&m->omsg.h, msg->h.id, ResponseFlags); - ackEnd = putLLQ(&m->omsg, m->omsg.data, q, &opt->u.llq); - if (ackEnd) mDNSSendDNSMessage(m, &m->omsg, ackEnd, mDNSInterface_Any, q->LocalSocket, srcaddr, srcport, mDNSNULL, mDNSNULL); - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - debugf("uDNS_LLQ_Events: q->state == LLQ_Established msg->h.id %d q->TargetQID %d", mDNSVal16(msg->h.id), mDNSVal16(q->TargetQID)); - *matchQuestion = q; - return uDNS_LLQ_Events; - } - if (opt && mDNSSameOpaque16(msg->h.id, q->TargetQID)) - { - if (q->state == LLQ_Established && opt->u.llq.llqOp == kLLQOp_Refresh && mDNSSameOpaque64(&opt->u.llq.id, &q->id) && msg->h.numAdditionals && !msg->h.numAnswers) - { - if (opt->u.llq.err != LLQErr_NoError) LogMsg("recvRefreshReply: received error %d from server", opt->u.llq.err); - else - { - //LogInfo("Received refresh confirmation ntries %d for %##s (%s)", q->ntries, q->qname.c, DNSTypeName(q->qtype)); - // If we're waiting to go to sleep, then this LLQ deletion may have been the thing - // we were waiting for, so schedule another check to see if we can sleep now. - if (opt->u.llq.llqlease == 0 && m->SleepLimit) m->NextScheduledSPRetry = m->timenow; - GrantCacheExtensions(m, q, opt->u.llq.llqlease); - SetLLQTimer(m, q, &opt->u.llq); - q->ntries = 0; - } - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - *matchQuestion = q; - return uDNS_LLQ_Ignore; - } - if (q->state < LLQ_Established && mDNSSameAddress(srcaddr, &q->servAddr)) - { - LLQ_State oldstate = q->state; - recvSetupResponse(m, msg->h.flags.b[1] & kDNSFlag1_RC_Mask, q, &opt->u.llq); - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - // We have a protocol anomaly here in the LLQ definition. - // Both the challenge packet from the server and the ack+answers packet have opt->u.llq.llqOp == kLLQOp_Setup. - // However, we need to treat them differently: - // The challenge packet has no answers in it, and tells us nothing about whether our cache entries - // are still valid, so this packet should not cause us to do anything that messes with our cache. - // The ack+answers packet gives us the whole truth, so we should handle it by updating our cache - // to match the answers in the packet, and only the answers in the packet. - *matchQuestion = q; - return (oldstate == LLQ_SecondaryRequest ? uDNS_LLQ_Entire : uDNS_LLQ_Ignore); - } - } - } - } - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - } - *matchQuestion = mDNSNULL; - return uDNS_LLQ_Not; - } - -// Stub definition of TCPSocket_struct so we can access flags field. (Rest of TCPSocket_struct is platform-dependent.) -struct TCPSocket_struct { TCPSocketFlags flags; /* ... */ }; - -// tcpCallback is called to handle events (e.g. connection opening and data reception) on TCP connections for -// Private DNS operations -- private queries, private LLQs, private record updates and private service updates -mDNSlocal void tcpCallback(TCPSocket *sock, void *context, mDNSBool ConnectionEstablished, mStatus err) - { - tcpInfo_t *tcpInfo = (tcpInfo_t *)context; - mDNSBool closed = mDNSfalse; - mDNS *m = tcpInfo->m; - DNSQuestion *const q = tcpInfo->question; - tcpInfo_t **backpointer = - q ? &q ->tcp : - tcpInfo->rr ? &tcpInfo->rr ->tcp : mDNSNULL; - if (backpointer && *backpointer != tcpInfo) - LogMsg("tcpCallback: %d backpointer %p incorrect tcpInfo %p question %p rr %p", - mDNSPlatformTCPGetFD(tcpInfo->sock), *backpointer, tcpInfo, q, tcpInfo->rr); - - if (err) goto exit; - - if (ConnectionEstablished) - { - mDNSu8 *end = ((mDNSu8*) &tcpInfo->request) + tcpInfo->requestLen; - DomainAuthInfo *AuthInfo; - - // Defensive coding for <rdar://problem/5546824> Crash in mDNSResponder at GetAuthInfoForName_internal + 366 - // Don't know yet what's causing this, but at least we can be cautious and try to avoid crashing if we find our pointers in an unexpected state - if (tcpInfo->rr && tcpInfo->rr->resrec.name != &tcpInfo->rr->namestorage) - LogMsg("tcpCallback: ERROR: tcpInfo->rr->resrec.name %p != &tcpInfo->rr->namestorage %p", - tcpInfo->rr->resrec.name, &tcpInfo->rr->namestorage); - if (tcpInfo->rr && tcpInfo->rr-> resrec.name != &tcpInfo->rr-> namestorage) return; - - AuthInfo = tcpInfo->rr ? GetAuthInfoForName(m, tcpInfo->rr->resrec.name) : mDNSNULL; - - // connection is established - send the message - if (q && q->LongLived && q->state == LLQ_Established) - { - // Lease renewal over TCP, resulting from opening a TCP connection in sendLLQRefresh - end = ((mDNSu8*) &tcpInfo->request) + tcpInfo->requestLen; - } - else if (q && q->LongLived && q->state != LLQ_Poll && !mDNSIPPortIsZero(m->LLQNAT.ExternalPort) && !mDNSIPPortIsZero(q->servPort)) - { - // Notes: - // If we have a NAT port mapping, ExternalPort is the external port - // If we have a routable address so we don't need a port mapping, ExternalPort is the same as our own internal port - // If we need a NAT port mapping but can't get one, then ExternalPort is zero - LLQOptData llqData; // set llq rdata - llqData.vers = kLLQ_Vers; - llqData.llqOp = kLLQOp_Setup; - llqData.err = GetLLQEventPort(m, &tcpInfo->Addr); // We're using TCP; tell server what UDP port to send notifications to - LogInfo("tcpCallback: eventPort %d", llqData.err); - llqData.id = zeroOpaque64; - llqData.llqlease = kLLQ_DefLease; - InitializeDNSMessage(&tcpInfo->request.h, q->TargetQID, uQueryFlags); - end = putLLQ(&tcpInfo->request, tcpInfo->request.data, q, &llqData); - if (!end) { LogMsg("ERROR: tcpCallback - putLLQ"); err = mStatus_UnknownErr; goto exit; } - AuthInfo = q->AuthInfo; // Need to add TSIG to this message - q->ntries = 0; // Reset ntries so that tcp/tls connection failures don't affect sendChallengeResponse failures - } - else if (q) - { - // LLQ Polling mode or non-LLQ uDNS over TCP - InitializeDNSMessage(&tcpInfo->request.h, q->TargetQID, uQueryFlags); - end = putQuestion(&tcpInfo->request, tcpInfo->request.data, tcpInfo->request.data + AbsoluteMaxDNSMessageData, &q->qname, q->qtype, q->qclass); - AuthInfo = q->AuthInfo; // Need to add TSIG to this message - } - - err = mDNSSendDNSMessage(m, &tcpInfo->request, end, mDNSInterface_Any, mDNSNULL, &tcpInfo->Addr, tcpInfo->Port, sock, AuthInfo); - if (err) { debugf("ERROR: tcpCallback: mDNSSendDNSMessage - %d", err); err = mStatus_UnknownErr; goto exit; } - - // Record time we sent this question - if (q) - { - mDNS_Lock(m); - q->LastQTime = m->timenow; - if (q->ThisQInterval < (256 * mDNSPlatformOneSecond)) // Now we have a TCP connection open, make sure we wait at least 256 seconds before retrying - q->ThisQInterval = (256 * mDNSPlatformOneSecond); - SetNextQueryTime(m, q); - mDNS_Unlock(m); - } - } - else - { - long n; - if (tcpInfo->nread < 2) // First read the two-byte length preceeding the DNS message - { - mDNSu8 *lenptr = (mDNSu8 *)&tcpInfo->replylen; - n = mDNSPlatformReadTCP(sock, lenptr + tcpInfo->nread, 2 - tcpInfo->nread, &closed); - if (n < 0) - { - LogMsg("ERROR: tcpCallback - attempt to read message length failed (%d)", n); - err = mStatus_ConnFailed; - goto exit; - } - else if (closed) - { - // It's perfectly fine for this socket to close after the first reply. The server might - // be sending gratuitous replies using UDP and doesn't have a need to leave the TCP socket open. - // We'll only log this event if we've never received a reply before. - // BIND 9 appears to close an idle connection after 30 seconds. - if (tcpInfo->numReplies == 0) - { - LogMsg("ERROR: socket closed prematurely tcpInfo->nread = %d", tcpInfo->nread); - err = mStatus_ConnFailed; - goto exit; - } - else - { - // Note that we may not be doing the best thing if an error occurs after we've sent a second request - // over this tcp connection. That is, we only track whether we've received at least one response - // which may have been to a previous request sent over this tcp connection. - if (backpointer) *backpointer = mDNSNULL; // Clear client backpointer FIRST so we don't risk double-disposing our tcpInfo_t - DisposeTCPConn(tcpInfo); - return; - } - } - - tcpInfo->nread += n; - if (tcpInfo->nread < 2) goto exit; - - tcpInfo->replylen = (mDNSu16)((mDNSu16)lenptr[0] << 8 | lenptr[1]); - if (tcpInfo->replylen < sizeof(DNSMessageHeader)) - { LogMsg("ERROR: tcpCallback - length too short (%d bytes)", tcpInfo->replylen); err = mStatus_UnknownErr; goto exit; } - - tcpInfo->reply = mDNSPlatformMemAllocate(tcpInfo->replylen); - if (!tcpInfo->reply) { LogMsg("ERROR: tcpCallback - malloc failed"); err = mStatus_NoMemoryErr; goto exit; } - } - - n = mDNSPlatformReadTCP(sock, ((char *)tcpInfo->reply) + (tcpInfo->nread - 2), tcpInfo->replylen - (tcpInfo->nread - 2), &closed); - - if (n < 0) - { - LogMsg("ERROR: tcpCallback - read returned %d", n); - err = mStatus_ConnFailed; - goto exit; - } - else if (closed) - { - if (tcpInfo->numReplies == 0) - { - LogMsg("ERROR: socket closed prematurely tcpInfo->nread = %d", tcpInfo->nread); - err = mStatus_ConnFailed; - goto exit; - } - else - { - // Note that we may not be doing the best thing if an error occurs after we've sent a second request - // over this tcp connection. That is, we only track whether we've received at least one response - // which may have been to a previous request sent over this tcp connection. - if (backpointer) *backpointer = mDNSNULL; // Clear client backpointer FIRST so we don't risk double-disposing our tcpInfo_t - DisposeTCPConn(tcpInfo); - return; - } - } - - tcpInfo->nread += n; - - if ((tcpInfo->nread - 2) == tcpInfo->replylen) - { - mDNSBool tls; - DNSMessage *reply = tcpInfo->reply; - mDNSu8 *end = (mDNSu8 *)tcpInfo->reply + tcpInfo->replylen; - mDNSAddr Addr = tcpInfo->Addr; - mDNSIPPort Port = tcpInfo->Port; - mDNSIPPort srcPort = zeroIPPort; - tcpInfo->numReplies++; - tcpInfo->reply = mDNSNULL; // Detach reply buffer from tcpInfo_t, to make sure client callback can't cause it to be disposed - tcpInfo->nread = 0; - tcpInfo->replylen = 0; - - // If we're going to dispose this connection, do it FIRST, before calling client callback - // Note: Sleep code depends on us clearing *backpointer here -- it uses the clearing of rr->tcp - // as the signal that the DNS deregistration operation with the server has completed, and the machine may now sleep - // If we clear the tcp pointer in the question, mDNSCoreReceiveResponse cannot find a matching question. Hence - // we store the minimal information i.e., the source port of the connection in the question itself. - // Dereference sock before it is disposed in DisposeTCPConn below. - - if (sock->flags & kTCPSocketFlags_UseTLS) tls = mDNStrue; - else tls = mDNSfalse; - - if (q && q->tcp) {srcPort = q->tcp->SrcPort; q->tcpSrcPort = srcPort;} - - if (backpointer) - if (!q || !q->LongLived || m->SleepState) - { *backpointer = mDNSNULL; DisposeTCPConn(tcpInfo); } - - mDNSCoreReceive(m, reply, end, &Addr, Port, tls ? (mDNSAddr *)1 : mDNSNULL, srcPort, 0); - // USE CAUTION HERE: Invoking mDNSCoreReceive may have caused the environment to change, including canceling this operation itself - - mDNSPlatformMemFree(reply); - return; - } - } - -exit: - - if (err) - { - // Clear client backpointer FIRST -- that way if one of the callbacks cancels its operation - // we won't end up double-disposing our tcpInfo_t - if (backpointer) *backpointer = mDNSNULL; - - mDNS_Lock(m); // Need to grab the lock to get m->timenow - - if (q) - { - if (q->ThisQInterval == 0) - { - // We get here when we fail to establish a new TCP/TLS connection that would have been used for a new LLQ request or an LLQ renewal. - // Note that ThisQInterval is also zero when sendChallengeResponse resends the LLQ request on an extant TCP/TLS connection. - q->LastQTime = m->timenow; - if (q->LongLived) - { - // We didn't get the chance to send our request packet before the TCP/TLS connection failed. - // We want to retry quickly, but want to back off exponentially in case the server is having issues. - // Since ThisQInterval was 0, we can't just multiply by QuestionIntervalStep, we must track the number - // of TCP/TLS connection failures using ntries. - mDNSu32 count = q->ntries + 1; // want to wait at least 1 second before retrying - - q->ThisQInterval = InitialQuestionInterval; - - for (;count;count--) - q->ThisQInterval *= QuestionIntervalStep; - - if (q->ThisQInterval > LLQ_POLL_INTERVAL) - q->ThisQInterval = LLQ_POLL_INTERVAL; - else - q->ntries++; - - LogMsg("tcpCallback: stream connection for LLQ %##s (%s) failed %d times, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ntries, q->ThisQInterval); - } - else - { - q->ThisQInterval = MAX_UCAST_POLL_INTERVAL; - LogMsg("tcpCallback: stream connection for %##s (%s) failed, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); - } - SetNextQueryTime(m, q); - } - else if (NextQSendTime(q) - m->timenow > (q->LongLived ? LLQ_POLL_INTERVAL : MAX_UCAST_POLL_INTERVAL)) - { - // If we get an error and our next scheduled query for this question is more than the max interval from now, - // reset the next query to ensure we wait no longer the maximum interval from now before trying again. - q->LastQTime = m->timenow; - q->ThisQInterval = q->LongLived ? LLQ_POLL_INTERVAL : MAX_UCAST_POLL_INTERVAL; - SetNextQueryTime(m, q); - LogMsg("tcpCallback: stream connection for %##s (%s) failed, retrying in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); - } - - // We're about to dispose of the TCP connection, so we must reset the state to retry over TCP/TLS - // because sendChallengeResponse will send the query via UDP if we don't have a tcp pointer. - // Resetting to LLQ_InitialRequest will cause uDNS_CheckCurrentQuestion to call startLLQHandshake, which - // will attempt to establish a new tcp connection. - if (q->LongLived && q->state == LLQ_SecondaryRequest) - q->state = LLQ_InitialRequest; - - // ConnFailed may happen if the server sends a TCP reset or TLS fails, in which case we want to retry establishing the LLQ - // quickly rather than switching to polling mode. This case is handled by the above code to set q->ThisQInterval just above. - // If the error isn't ConnFailed, then the LLQ is in bad shape, so we switch to polling mode. - if (err != mStatus_ConnFailed) - { - if (q->LongLived && q->state != LLQ_Poll) StartLLQPolling(m, q); - } - } - - mDNS_Unlock(m); - - DisposeTCPConn(tcpInfo); - } - } - -mDNSlocal tcpInfo_t *MakeTCPConn(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, - TCPSocketFlags flags, const mDNSAddr *const Addr, const mDNSIPPort Port, domainname *hostname, - DNSQuestion *const question, AuthRecord *const rr) - { - mStatus err; - mDNSIPPort srcport = zeroIPPort; - tcpInfo_t *info; - - if ((flags & kTCPSocketFlags_UseTLS) && (!hostname || !hostname->c[0])) - { LogMsg("MakeTCPConn: TLS connection being setup with NULL hostname"); return mDNSNULL; } - - info = (tcpInfo_t *)mDNSPlatformMemAllocate(sizeof(tcpInfo_t)); - if (!info) { LogMsg("ERROR: MakeTCP - memallocate failed"); return(mDNSNULL); } - mDNSPlatformMemZero(info, sizeof(tcpInfo_t)); - - info->m = m; - info->sock = mDNSPlatformTCPSocket(m, flags, &srcport); - info->requestLen = 0; - info->question = question; - info->rr = rr; - info->Addr = *Addr; - info->Port = Port; - info->reply = mDNSNULL; - info->replylen = 0; - info->nread = 0; - info->numReplies = 0; - info->SrcPort = srcport; - - if (msg) - { - info->requestLen = (int) (end - ((mDNSu8*)msg)); - mDNSPlatformMemCopy(&info->request, msg, info->requestLen); - } - - if (!info->sock) { LogMsg("MakeTCPConn: unable to create TCP socket"); mDNSPlatformMemFree(info); return(mDNSNULL); } - err = mDNSPlatformTCPConnect(info->sock, Addr, Port, hostname, (question ? question->InterfaceID : mDNSNULL), tcpCallback, info); - - // Probably suboptimal here. - // Instead of returning mDNSNULL here on failure, we should probably invoke the callback with an error code. - // That way clients can put all the error handling and retry/recovery code in one place, - // instead of having to handle immediate errors in one place and async errors in another. - // Also: "err == mStatus_ConnEstablished" probably never happens. - - // Don't need to log "connection failed" in customer builds -- it happens quite often during sleep, wake, configuration changes, etc. - if (err == mStatus_ConnEstablished) { tcpCallback(info->sock, info, mDNStrue, mStatus_NoError); } - else if (err != mStatus_ConnPending ) { LogInfo("MakeTCPConn: connection failed"); DisposeTCPConn(info); return(mDNSNULL); } - return(info); - } - -mDNSexport void DisposeTCPConn(struct tcpInfo_t *tcp) - { - mDNSPlatformTCPCloseConnection(tcp->sock); - if (tcp->reply) mDNSPlatformMemFree(tcp->reply); - mDNSPlatformMemFree(tcp); - } - -// Lock must be held -mDNSexport void startLLQHandshake(mDNS *m, DNSQuestion *q) - { - if (mDNSIPv4AddressIsOnes(m->LLQNAT.ExternalAddress)) - { - LogInfo("startLLQHandshake: waiting for NAT status for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - return; - } - - // Either we don't have NAT-PMP support (ExternalPort is zero) or behind a Double NAT that may or - // may not have NAT-PMP support (NATResult is non-zero) - if (mDNSIPPortIsZero(m->LLQNAT.ExternalPort) || m->LLQNAT.Result) - { - LogInfo("startLLQHandshake: Cannot receive inbound packets; will poll for %##s (%s) External Port %d, NAT Result %d", - q->qname.c, DNSTypeName(q->qtype), mDNSVal16(m->LLQNAT.ExternalPort), m->LLQNAT.Result); - StartLLQPolling(m, q); - return; - } - - if (mDNSIPPortIsZero(q->servPort)) - { - debugf("startLLQHandshake: StartGetZoneData for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - q->ThisQInterval = LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10); // Retry in approx 15 minutes - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - q->servAddr = zeroAddr; - // We know q->servPort is zero because of check above - if (q->nta) CancelGetZoneData(m, q->nta); - q->nta = StartGetZoneData(m, &q->qname, ZoneServiceLLQ, LLQGotZoneData, q); - return; - } - - if (PrivateQuery(q)) - { - if (q->tcp) LogInfo("startLLQHandshake: Disposing existing TCP connection for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } - if (!q->nta) - { - // Normally we lookup the zone data and then call this function. And we never free the zone data - // for "PrivateQuery". But sometimes this can happen due to some race conditions. When we - // switch networks, we might end up "Polling" the network e.g., we are behind a Double NAT. - // When we poll, we free the zone information as we send the query to the server (See - // PrivateQueryGotZoneData). The NAT callback (LLQNATCallback) may happen soon after that. If we - // are still behind Double NAT, we would have returned early in this function. But we could - // have switched to a network with no NATs and we should get the zone data again. - LogInfo("startLLQHandshake: nta is NULL for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - q->nta = StartGetZoneData(m, &q->qname, ZoneServiceLLQ, LLQGotZoneData, q); - return; - } - else if (!q->nta->Host.c[0]) - { - // This should not happen. If it happens, we print a log and MakeTCPConn will fail if it can't find a hostname - LogMsg("startLLQHandshake: ERROR!!: nta non NULL for %##s (%s) but HostName %d NULL, LongLived %d", q->qname.c, DNSTypeName(q->qtype), q->nta->Host.c[0], q->LongLived); - } - q->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_UseTLS, &q->servAddr, q->servPort, &q->nta->Host, q, mDNSNULL); - if (!q->tcp) - q->ThisQInterval = mDNSPlatformOneSecond * 5; // If TCP failed (transient networking glitch) try again in five seconds - else - { - q->state = LLQ_SecondaryRequest; // Right now, for private DNS, we skip the four-way LLQ handshake - q->ReqLease = kLLQ_DefLease; - q->ThisQInterval = 0; - } - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - } - else - { - debugf("startLLQHandshake: m->AdvertisedV4 %#a%s Server %#a:%d%s %##s (%s)", - &m->AdvertisedV4, mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) ? " (RFC 1918)" : "", - &q->servAddr, mDNSVal16(q->servPort), mDNSAddrIsRFC1918(&q->servAddr) ? " (RFC 1918)" : "", - q->qname.c, DNSTypeName(q->qtype)); - - if (q->ntries++ >= kLLQ_MAX_TRIES) - { - LogMsg("startLLQHandshake: %d failed attempts for LLQ %##s Polling.", kLLQ_MAX_TRIES, q->qname.c); - StartLLQPolling(m, q); - } - else - { - mDNSu8 *end; - LLQOptData llqData; - - // set llq rdata - llqData.vers = kLLQ_Vers; - llqData.llqOp = kLLQOp_Setup; - llqData.err = LLQErr_NoError; // Don't need to tell server UDP notification port when sending over UDP - llqData.id = zeroOpaque64; - llqData.llqlease = kLLQ_DefLease; - - InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); - end = putLLQ(&m->omsg, m->omsg.data, q, &llqData); - if (!end) { LogMsg("ERROR: startLLQHandshake - putLLQ"); StartLLQPolling(m,q); return; } - - mDNSSendDNSMessage(m, &m->omsg, end, mDNSInterface_Any, q->LocalSocket, &q->servAddr, q->servPort, mDNSNULL, mDNSNULL); - - // update question state - q->state = LLQ_InitialRequest; - q->ReqLease = kLLQ_DefLease; - q->ThisQInterval = (kLLQ_INIT_RESEND * mDNSPlatformOneSecond); - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - } - } - } - -// forward declaration so GetServiceTarget can do reverse lookup if needed -mDNSlocal void GetStaticHostname(mDNS *m); - -mDNSexport const domainname *GetServiceTarget(mDNS *m, AuthRecord *const rr) - { - debugf("GetServiceTarget %##s", rr->resrec.name->c); - - if (!rr->AutoTarget) // If not automatically tracking this host's current name, just return the existing target - return(&rr->resrec.rdata->u.srv.target); - else - { -#if APPLE_OSX_mDNSResponder - DomainAuthInfo *AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); - if (AuthInfo && AuthInfo->AutoTunnel) - { - // If this AutoTunnel is not yet active, start it now (which entails activating its NAT Traversal request, - // which will subsequently advertise the appropriate records when the NAT Traversal returns a result) - if (!AuthInfo->AutoTunnelNAT.clientContext && m->AutoTunnelHostAddr.b[0]) - { - LogInfo("GetServiceTarget: Calling SetupLocalAutoTunnelInterface_internal"); - SetupLocalAutoTunnelInterface_internal(m, mDNStrue); - } - if (AuthInfo->AutoTunnelHostRecord.namestorage.c[0] == 0) return(mDNSNULL); - debugf("GetServiceTarget: Returning %##s", AuthInfo->AutoTunnelHostRecord.namestorage.c); - return(&AuthInfo->AutoTunnelHostRecord.namestorage); - } - else -#endif // APPLE_OSX_mDNSResponder - { - const int srvcount = CountLabels(rr->resrec.name); - HostnameInfo *besthi = mDNSNULL, *hi; - int best = 0; - for (hi = m->Hostnames; hi; hi = hi->next) - if (hi->arv4.state == regState_Registered || hi->arv4.state == regState_Refresh || - hi->arv6.state == regState_Registered || hi->arv6.state == regState_Refresh) - { - int x, hostcount = CountLabels(&hi->fqdn); - for (x = hostcount < srvcount ? hostcount : srvcount; x > 0 && x > best; x--) - if (SameDomainName(SkipLeadingLabels(rr->resrec.name, srvcount - x), SkipLeadingLabels(&hi->fqdn, hostcount - x))) - { best = x; besthi = hi; } - } - - if (besthi) return(&besthi->fqdn); - } - if (m->StaticHostname.c[0]) return(&m->StaticHostname); - else GetStaticHostname(m); // asynchronously do reverse lookup for primary IPv4 address - LogInfo("GetServiceTarget: Returning NULL for %s", ARDisplayString(m, rr)); - return(mDNSNULL); - } - } - -mDNSlocal const domainname *PUBLIC_UPDATE_SERVICE_TYPE = (const domainname*)"\x0B_dns-update" "\x04_udp"; -mDNSlocal const domainname *PUBLIC_LLQ_SERVICE_TYPE = (const domainname*)"\x08_dns-llq" "\x04_udp"; - -mDNSlocal const domainname *PRIVATE_UPDATE_SERVICE_TYPE = (const domainname*)"\x0F_dns-update-tls" "\x04_tcp"; -mDNSlocal const domainname *PRIVATE_QUERY_SERVICE_TYPE = (const domainname*)"\x0E_dns-query-tls" "\x04_tcp"; -mDNSlocal const domainname *PRIVATE_LLQ_SERVICE_TYPE = (const domainname*)"\x0C_dns-llq-tls" "\x04_tcp"; - -#define ZoneDataSRV(X) (\ - (X)->ZoneService == ZoneServiceUpdate ? ((X)->ZonePrivate ? PRIVATE_UPDATE_SERVICE_TYPE : PUBLIC_UPDATE_SERVICE_TYPE) : \ - (X)->ZoneService == ZoneServiceQuery ? ((X)->ZonePrivate ? PRIVATE_QUERY_SERVICE_TYPE : (const domainname*)"" ) : \ - (X)->ZoneService == ZoneServiceLLQ ? ((X)->ZonePrivate ? PRIVATE_LLQ_SERVICE_TYPE : PUBLIC_LLQ_SERVICE_TYPE ) : (const domainname*)"") - -// Forward reference: GetZoneData_StartQuery references GetZoneData_QuestionCallback, and -// GetZoneData_QuestionCallback calls GetZoneData_StartQuery -mDNSlocal mStatus GetZoneData_StartQuery(mDNS *const m, ZoneData *zd, mDNSu16 qtype); - -// GetZoneData_QuestionCallback is called from normal client callback context (core API calls allowed) -mDNSlocal void GetZoneData_QuestionCallback(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) - { - ZoneData *zd = (ZoneData*)question->QuestionContext; - - debugf("GetZoneData_QuestionCallback: %s %s", AddRecord ? "Add" : "Rmv", RRDisplayString(m, answer)); - - if (!AddRecord) return; // Don't care about REMOVE events - if (AddRecord == QC_addnocache && answer->rdlength == 0) return; // Don't care about transient failure indications - if (answer->rrtype != question->qtype) return; // Don't care about CNAMEs - - if (answer->rrtype == kDNSType_SOA) - { - debugf("GetZoneData GOT SOA %s", RRDisplayString(m, answer)); - mDNS_StopQuery(m, question); - if (question->ThisQInterval != -1) - LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); - if (answer->rdlength) - { - AssignDomainName(&zd->ZoneName, answer->name); - zd->ZoneClass = answer->rrclass; - AssignDomainName(&zd->question.qname, &zd->ZoneName); - GetZoneData_StartQuery(m, zd, kDNSType_SRV); - } - else if (zd->CurrentSOA->c[0]) - { - DomainAuthInfo *AuthInfo = GetAuthInfoForName(m, zd->CurrentSOA); - if (AuthInfo && AuthInfo->AutoTunnel) - { - // To keep the load on the server down, we don't chop down on - // SOA lookups for AutoTunnels - LogInfo("GetZoneData_QuestionCallback: not chopping labels for %##s", zd->CurrentSOA->c); - zd->ZoneDataCallback(m, mStatus_NoSuchNameErr, zd); - } - else - { - zd->CurrentSOA = (domainname *)(zd->CurrentSOA->c + zd->CurrentSOA->c[0]+1); - AssignDomainName(&zd->question.qname, zd->CurrentSOA); - GetZoneData_StartQuery(m, zd, kDNSType_SOA); - } - } - else - { - LogInfo("GetZoneData recursed to root label of %##s without finding SOA", zd->ChildName.c); - zd->ZoneDataCallback(m, mStatus_NoSuchNameErr, zd); - } - } - else if (answer->rrtype == kDNSType_SRV) - { - debugf("GetZoneData GOT SRV %s", RRDisplayString(m, answer)); - mDNS_StopQuery(m, question); - if (question->ThisQInterval != -1) - LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); -// Right now we don't want to fail back to non-encrypted operations -// If the AuthInfo has the AutoTunnel field set, then we want private or nothing -// <rdar://problem/5687667> BTMM: Don't fallback to unencrypted operations when SRV lookup fails -#if 0 - if (!answer->rdlength && zd->ZonePrivate && zd->ZoneService != ZoneServiceQuery) - { - zd->ZonePrivate = mDNSfalse; // Causes ZoneDataSRV() to yield a different SRV name when building the query - GetZoneData_StartQuery(m, zd, kDNSType_SRV); // Try again, non-private this time - } - else -#endif - { - if (answer->rdlength) - { - AssignDomainName(&zd->Host, &answer->rdata->u.srv.target); - zd->Port = answer->rdata->u.srv.port; - AssignDomainName(&zd->question.qname, &zd->Host); - GetZoneData_StartQuery(m, zd, kDNSType_A); - } - else - { - zd->ZonePrivate = mDNSfalse; - zd->Host.c[0] = 0; - zd->Port = zeroIPPort; - zd->Addr = zeroAddr; - zd->ZoneDataCallback(m, mStatus_NoError, zd); - } - } - } - else if (answer->rrtype == kDNSType_A) - { - debugf("GetZoneData GOT A %s", RRDisplayString(m, answer)); - mDNS_StopQuery(m, question); - if (question->ThisQInterval != -1) - LogMsg("GetZoneData_QuestionCallback: Question %##s (%s) ThisQInterval %d not -1", question->qname.c, DNSTypeName(question->qtype), question->ThisQInterval); - zd->Addr.type = mDNSAddrType_IPv4; - zd->Addr.ip.v4 = (answer->rdlength == 4) ? answer->rdata->u.ipv4 : zerov4Addr; - // In order to simulate firewalls blocking our outgoing TCP connections, returning immediate ICMP errors or TCP resets, - // the code below will make us try to connect to loopback, resulting in an immediate "port unreachable" failure. - // This helps us test to make sure we handle this case gracefully - // <rdar://problem/5607082> BTMM: mDNSResponder taking 100 percent CPU after upgrading to 10.5.1 -#if 0 - zd->Addr.ip.v4.b[0] = 127; - zd->Addr.ip.v4.b[1] = 0; - zd->Addr.ip.v4.b[2] = 0; - zd->Addr.ip.v4.b[3] = 1; -#endif - // The caller needs to free the memory when done with zone data - zd->ZoneDataCallback(m, mStatus_NoError, zd); - } - } - -// GetZoneData_StartQuery is called from normal client context (lock not held, or client callback) -mDNSlocal mStatus GetZoneData_StartQuery(mDNS *const m, ZoneData *zd, mDNSu16 qtype) - { - if (qtype == kDNSType_SRV) - { - AssignDomainName(&zd->question.qname, ZoneDataSRV(zd)); - AppendDomainName(&zd->question.qname, &zd->ZoneName); - debugf("lookupDNSPort %##s", zd->question.qname.c); - } - - // CancelGetZoneData can get called at any time. We should stop the question if it has not been - // stopped already. A value of -1 for ThisQInterval indicates that the question is not active - // yet. - zd->question.ThisQInterval = -1; - zd->question.InterfaceID = mDNSInterface_Any; - zd->question.Target = zeroAddr; - //zd->question.qname.c[0] = 0; // Already set - zd->question.qtype = qtype; - zd->question.qclass = kDNSClass_IN; - zd->question.LongLived = mDNSfalse; - zd->question.ExpectUnique = mDNStrue; - zd->question.ForceMCast = mDNSfalse; - zd->question.ReturnIntermed = mDNStrue; - zd->question.SuppressUnusable = mDNSfalse; - zd->question.SearchListIndex = 0; - zd->question.AppendSearchDomains = 0; - zd->question.RetryWithSearchDomains = mDNSfalse; - zd->question.TimeoutQuestion = 0; - zd->question.WakeOnResolve = 0; - zd->question.qnameOrig = mDNSNULL; - zd->question.QuestionCallback = GetZoneData_QuestionCallback; - zd->question.QuestionContext = zd; - - //LogMsg("GetZoneData_StartQuery %##s (%s) %p", zd->question.qname.c, DNSTypeName(zd->question.qtype), zd->question.Private); - return(mDNS_StartQuery(m, &zd->question)); - } - -// StartGetZoneData is an internal routine (i.e. must be called with the lock already held) -mDNSexport ZoneData *StartGetZoneData(mDNS *const m, const domainname *const name, const ZoneService target, ZoneDataCallback callback, void *ZoneDataContext) - { - DomainAuthInfo *AuthInfo = GetAuthInfoForName_internal(m, name); - int initialskip = (AuthInfo && AuthInfo->AutoTunnel) ? DomainNameLength(name) - DomainNameLength(&AuthInfo->domain) : 0; - ZoneData *zd = (ZoneData*)mDNSPlatformMemAllocate(sizeof(ZoneData)); - if (!zd) { LogMsg("ERROR: StartGetZoneData - mDNSPlatformMemAllocate failed"); return mDNSNULL; } - mDNSPlatformMemZero(zd, sizeof(ZoneData)); - AssignDomainName(&zd->ChildName, name); - zd->ZoneService = target; - zd->CurrentSOA = (domainname *)(&zd->ChildName.c[initialskip]); - zd->ZoneName.c[0] = 0; - zd->ZoneClass = 0; - zd->Host.c[0] = 0; - zd->Port = zeroIPPort; - zd->Addr = zeroAddr; - zd->ZonePrivate = AuthInfo && AuthInfo->AutoTunnel ? mDNStrue : mDNSfalse; - zd->ZoneDataCallback = callback; - zd->ZoneDataContext = ZoneDataContext; - - zd->question.QuestionContext = zd; - - mDNS_DropLockBeforeCallback(); // GetZoneData_StartQuery expects to be called from a normal callback, so we emulate that here - if (AuthInfo && AuthInfo->AutoTunnel && !mDNSIPPortIsZero(AuthInfo->port)) - { - LogInfo("StartGetZoneData: Bypassing SOA, SRV query for %##s", AuthInfo->domain.c); - // We bypass SOA and SRV queries if we know the hostname and port already from the configuration. - // Today this is only true for AutoTunnel. As we bypass, we need to infer a few things: - // - // 1. Zone name is the same as the AuthInfo domain - // 2. ZoneClass is kDNSClass_IN which should be a safe assumption - // - // If we want to make this bypass mechanism work for non-AutoTunnels also, (1) has to hold - // good. Otherwise, it has to be configured also. - - AssignDomainName(&zd->ZoneName, &AuthInfo->domain); - zd->ZoneClass = kDNSClass_IN; - AssignDomainName(&zd->Host, &AuthInfo->hostname); - zd->Port = AuthInfo->port; - AssignDomainName(&zd->question.qname, &zd->Host); - GetZoneData_StartQuery(m, zd, kDNSType_A); - } - else - { - if (AuthInfo && AuthInfo->AutoTunnel) LogInfo("StartGetZoneData: Not Bypassing SOA, SRV query for %##s", AuthInfo->domain.c); - AssignDomainName(&zd->question.qname, zd->CurrentSOA); - GetZoneData_StartQuery(m, zd, kDNSType_SOA); - } - mDNS_ReclaimLockAfterCallback(); - - return zd; - } - -// Returns if the question is a GetZoneData question. These questions are special in -// that they are created internally while resolving a private query or LLQs. -mDNSexport mDNSBool IsGetZoneDataQuestion(DNSQuestion *q) - { - if (q->QuestionCallback == GetZoneData_QuestionCallback) return(mDNStrue); - else return(mDNSfalse); - } - -// GetZoneData queries are a special case -- even if we have a key for them, we don't do them privately, -// because that would result in an infinite loop (i.e. to do a private query we first need to get -// the _dns-query-tls SRV record for the zone, and we can't do *that* privately because to do so -// we'd need to already know the _dns-query-tls SRV record. -// Also, as a general rule, we never do SOA queries privately -mDNSexport DomainAuthInfo *GetAuthInfoForQuestion(mDNS *m, const DNSQuestion *const q) // Must be called with lock held - { - if (q->QuestionCallback == GetZoneData_QuestionCallback) return(mDNSNULL); - if (q->qtype == kDNSType_SOA ) return(mDNSNULL); - return(GetAuthInfoForName_internal(m, &q->qname)); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - host name and interface management -#endif - -mDNSlocal void SendRecordRegistration(mDNS *const m, AuthRecord *rr); -mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr); -mDNSlocal mDNSBool IsRecordMergeable(mDNS *const m, AuthRecord *rr, mDNSs32 time); - -// When this function is called, service record is already deregistered. We just -// have to deregister the PTR and TXT records. -mDNSlocal void UpdateAllServiceRecords(mDNS *const m, AuthRecord *rr, mDNSBool reg) - { - AuthRecord *r, *srvRR; - - if (rr->resrec.rrtype != kDNSType_SRV) { LogMsg("UpdateAllServiceRecords:ERROR!! ResourceRecord not a service record %s", ARDisplayString(m, rr)); return; } - - if (reg && rr->state == regState_NoTarget) { LogMsg("UpdateAllServiceRecords:ERROR!! SRV record %s in noTarget state during registration", ARDisplayString(m, rr)); return; } - - LogInfo("UpdateAllServiceRecords: ResourceRecord %s", ARDisplayString(m, rr)); - - for (r = m->ResourceRecords; r; r=r->next) - { - if (!AuthRecord_uDNS(r)) continue; - srvRR = mDNSNULL; - if (r->resrec.rrtype == kDNSType_PTR) - srvRR = r->Additional1; - else if (r->resrec.rrtype == kDNSType_TXT) - srvRR = r->DependentOn; - if (srvRR && srvRR->resrec.rrtype != kDNSType_SRV) - LogMsg("UpdateAllServiceRecords: ERROR!! Resource record %s wrong, expecting SRV type", ARDisplayString(m, srvRR)); - if (srvRR == rr) - { - if (!reg) - { - LogInfo("UpdateAllServiceRecords: deregistering %s", ARDisplayString(m, r)); - r->SRVChanged = mDNStrue; - r->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - r->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - r->state = regState_DeregPending; - } - else - { - // Clearing SRVchanged is a safety measure. If our pevious dereg never - // came back and we had a target change, we are starting fresh - r->SRVChanged = mDNSfalse; - // if it is already registered or in the process of registering, then don't - // bother re-registering. This happens today for non-BTMM domains where the - // TXT and PTR get registered before SRV records because of the delay in - // getting the port mapping. There is no point in re-registering the TXT - // and PTR records. - if ((r->state == regState_Registered) || - (r->state == regState_Pending && r->nta && !mDNSIPv4AddressIsZero(r->nta->Addr.ip.v4))) - LogInfo("UpdateAllServiceRecords: not registering %s, state %d", ARDisplayString(m, r), r->state); - else - { - LogInfo("UpdateAllServiceRecords: registering %s, state %d", ARDisplayString(m, r), r->state); - ActivateUnicastRegistration(m, r); - } - } - } - } - } - -// Called in normal client context (lock not held) -// Currently only supports SRV records for nat mapping -mDNSlocal void CompleteRecordNatMap(mDNS *m, NATTraversalInfo *n) - { - const domainname *target; - domainname *srvt; - AuthRecord *rr = (AuthRecord *)n->clientContext; - debugf("SRVNatMap complete %.4a IntPort %u ExternalPort %u NATLease %u", &n->ExternalAddress, mDNSVal16(n->IntPort), mDNSVal16(n->ExternalPort), n->NATLease); - - if (!rr) { LogMsg("CompleteRecordNatMap called with unknown AuthRecord object"); return; } - if (!n->NATLease) { LogMsg("CompleteRecordNatMap No NATLease for %s", ARDisplayString(m, rr)); return; } - - if (rr->resrec.rrtype != kDNSType_SRV) {LogMsg("CompleteRecordNatMap: Not a service record %s", ARDisplayString(m, rr)); return; } - - if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) { LogInfo("CompleteRecordNatMap called for %s, Service deregistering", ARDisplayString(m, rr)); return; } - - if (rr->state == regState_DeregPending) { LogInfo("CompleteRecordNatMap called for %s, record in DeregPending", ARDisplayString(m, rr)); return; } - - // As we free the zone info after registering/deregistering with the server (See hndlRecordUpdateReply), - // we need to restart the get zone data and nat mapping request to get the latest mapping result as we can't handle it - // at this moment. Restart from the beginning. - if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) - { - LogInfo("CompleteRecordNatMap called for %s but no zone information!", ARDisplayString(m, rr)); - // We need to clear out the NATinfo state so that it will result in re-acquiring the mapping - // and hence this callback called again. - if (rr->NATinfo.clientContext) - { - mDNS_StopNATOperation_internal(m, &rr->NATinfo); - rr->NATinfo.clientContext = mDNSNULL; - } - rr->state = regState_Pending; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - return; - } - - mDNS_Lock(m); - // Reevaluate the target always as Target could have changed while - // we were getting the port mapping (See UpdateOneSRVRecord) - target = GetServiceTarget(m, rr); - srvt = GetRRDomainNameTarget(&rr->resrec); - if (!target || target->c[0] == 0 || mDNSIPPortIsZero(n->ExternalPort)) - { - if (target && target->c[0]) - LogInfo("CompleteRecordNatMap - Target %##s for ResourceRecord %##s, ExternalPort %d", target->c, rr->resrec.name->c, mDNSVal16(n->ExternalPort)); - else - LogInfo("CompleteRecordNatMap - no target for %##s, ExternalPort %d", rr->resrec.name->c, mDNSVal16(n->ExternalPort)); - if (srvt) srvt->c[0] = 0; - rr->state = regState_NoTarget; - rr->resrec.rdlength = rr->resrec.rdestimate = 0; - mDNS_Unlock(m); - UpdateAllServiceRecords(m, rr, mDNSfalse); - return; - } - LogInfo("CompleteRecordNatMap - Target %##s for ResourceRecord %##s, ExternalPort %d", target->c, rr->resrec.name->c, mDNSVal16(n->ExternalPort)); - // This function might get called multiple times during a network transition event. Previosuly, we could - // have put the SRV record in NoTarget state above and deregistered all the other records. When this - // function gets called again with a non-zero ExternalPort, we need to set the target and register the - // other records again. - if (srvt && !SameDomainName(srvt, target)) - { - AssignDomainName(srvt, target); - SetNewRData(&rr->resrec, mDNSNULL, 0); // Update rdlength, rdestimate, rdatahash - } - - // SRVChanged is set when when the target of the SRV record changes (See UpdateOneSRVRecord). - // As a result of the target change, we might register just that SRV Record if it was - // previously registered and we have a new target OR deregister SRV (and the associated - // PTR/TXT records) if we don't have a target anymore. When we get a response from the server, - // SRVChanged state tells that we registered/deregistered because of a target change - // and hence handle accordingly e.g., if we deregistered, put the records in NoTarget state OR - // if we registered then put it in Registered state. - // - // Here, we are registering all the records again from the beginning. Treat this as first time - // registration rather than a temporary target change. - rr->SRVChanged = mDNSfalse; - - // We want IsRecordMergeable to check whether it is a record whose update can be - // sent with others. We set the time before we call IsRecordMergeable, so that - // it does not fail this record based on time. We are interested in other checks - // at this time - rr->state = regState_Pending; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - if (IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) - // Delay the record registration by MERGE_DELAY_TIME so that we can merge them - // into one update - rr->LastAPTime += MERGE_DELAY_TIME; - mDNS_Unlock(m); - // We call this always even though it may not be necessary always e.g., normal registration - // process where TXT and PTR gets registered followed by the SRV record after it gets - // the port mapping. In that case, UpdateAllServiceRecords handles the optimization. The - // update of TXT and PTR record is required if we entered noTargetState before as explained - // above. - UpdateAllServiceRecords(m, rr, mDNStrue); - } - -mDNSlocal void StartRecordNatMap(mDNS *m, AuthRecord *rr) - { - const mDNSu8 *p; - mDNSu8 protocol; - - if (rr->resrec.rrtype != kDNSType_SRV) - { - LogInfo("StartRecordNatMap: Resource Record %##s type %d, not supported", rr->resrec.name->c, rr->resrec.rrtype); - return; - } - p = rr->resrec.name->c; - //Assume <Service Instance>.<App Protocol>.<Transport protocol>.<Name> - // Skip the first two labels to get to the transport protocol - if (p[0]) p += 1 + p[0]; - if (p[0]) p += 1 + p[0]; - if (SameDomainLabel(p, (mDNSu8 *)"\x4" "_tcp")) protocol = NATOp_MapTCP; - else if (SameDomainLabel(p, (mDNSu8 *)"\x4" "_udp")) protocol = NATOp_MapUDP; - else { LogMsg("StartRecordNatMap: could not determine transport protocol of service %##s", rr->resrec.name->c); return; } - - //LogMsg("StartRecordNatMap: clientContext %p IntPort %d srv.port %d %s", - // rr->NATinfo.clientContext, mDNSVal16(rr->NATinfo.IntPort), mDNSVal16(rr->resrec.rdata->u.srv.port), ARDisplayString(m, rr)); - if (rr->NATinfo.clientContext) mDNS_StopNATOperation_internal(m, &rr->NATinfo); - rr->NATinfo.Protocol = protocol; - - // Shouldn't be trying to set IntPort here -- - // BuildUpdateMessage overwrites srs->RR_SRV.resrec.rdata->u.srv.port with external (mapped) port number - rr->NATinfo.IntPort = rr->resrec.rdata->u.srv.port; - rr->NATinfo.RequestedPort = rr->resrec.rdata->u.srv.port; - rr->NATinfo.NATLease = 0; // Request default lease - rr->NATinfo.clientCallback = CompleteRecordNatMap; - rr->NATinfo.clientContext = rr; - mDNS_StartNATOperation_internal(m, &rr->NATinfo); - } - -// Unlink an Auth Record from the m->ResourceRecords list. -// When a resource record enters regState_NoTarget initially, mDNS_Register_internal -// does not initialize completely e.g., it cannot check for duplicates etc. The resource -// record is temporarily left in the ResourceRecords list so that we can initialize later -// when the target is resolvable. Similarly, when host name changes, we enter regState_NoTarget -// and we do the same. - -// This UnlinkResourceRecord routine is very worrying. It bypasses all the normal cleanup performed -// by mDNS_Deregister_internal and just unceremoniously cuts the record from the active list. -// This is why re-regsitering this record was producing syslog messages like this: -// "Error! Tried to add a NAT traversal that's already in the active list" -// Right now UnlinkResourceRecord is fortunately only called by RegisterAllServiceRecords, -// which then immediately calls mDNS_Register_internal to re-register the record, which probably -// masked more serious problems. Any other use of UnlinkResourceRecord is likely to lead to crashes. -// For now we'll workaround that specific problem by explicitly calling mDNS_StopNATOperation_internal, -// but long-term we should either stop cancelling the record registration and then re-registering it, -// or if we really do need to do this for some reason it should be done via the usual -// mDNS_Deregister_internal path instead of just cutting the record from the list. - -mDNSlocal mStatus UnlinkResourceRecord(mDNS *const m, AuthRecord *const rr) - { - AuthRecord **list = &m->ResourceRecords; - while (*list && *list != rr) list = &(*list)->next; - if (*list) - { - *list = rr->next; - rr->next = mDNSNULL; - - // Temporary workaround to cancel any active NAT mapping operation - if (rr->NATinfo.clientContext) - { - mDNS_StopNATOperation_internal(m, &rr->NATinfo); - rr->NATinfo.clientContext = mDNSNULL; - if (rr->resrec.rrtype == kDNSType_SRV) rr->resrec.rdata->u.srv.port = rr->NATinfo.IntPort; - } - - return(mStatus_NoError); - } - LogMsg("UnlinkResourceRecord:ERROR!! - no such active record %##s", rr->resrec.name->c); - return(mStatus_NoSuchRecord); - } - -// We need to go through mDNS_Register again as we did not complete the -// full initialization last time e.g., duplicate checks. -// After we register, we will be in regState_GetZoneData. -mDNSlocal void RegisterAllServiceRecords(mDNS *const m, AuthRecord *rr) - { - LogInfo("RegisterAllServiceRecords: Service Record %##s", rr->resrec.name->c); - // First Register the service record, we do this differently from other records because - // when it entered NoTarget state, it did not go through complete initialization - rr->SRVChanged = mDNSfalse; - UnlinkResourceRecord(m, rr); - mDNS_Register_internal(m, rr); - // Register the other records - UpdateAllServiceRecords(m, rr, mDNStrue); - } - -// Called with lock held -mDNSlocal void UpdateOneSRVRecord(mDNS *m, AuthRecord *rr) - { - // Target change if: - // We have a target and were previously waiting for one, or - // We had a target and no longer do, or - // The target has changed - - domainname *curtarget = &rr->resrec.rdata->u.srv.target; - const domainname *const nt = GetServiceTarget(m, rr); - const domainname *const newtarget = nt ? nt : (domainname*)""; - mDNSBool TargetChanged = (newtarget->c[0] && rr->state == regState_NoTarget) || !SameDomainName(curtarget, newtarget); - mDNSBool HaveZoneData = rr->nta && !mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4); - - // Nat state change if: - // We were behind a NAT, and now we are behind a new NAT, or - // We're not behind a NAT but our port was previously mapped to a different external port - // We were not behind a NAT and now we are - - mDNSIPPort port = rr->resrec.rdata->u.srv.port; - mDNSBool NowNeedNATMAP = (rr->AutoTarget == Target_AutoHostAndNATMAP && !mDNSIPPortIsZero(port) && mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) && rr->nta && !mDNSAddrIsRFC1918(&rr->nta->Addr)); - mDNSBool WereBehindNAT = (rr->NATinfo.clientContext != mDNSNULL); - mDNSBool PortWasMapped = (rr->NATinfo.clientContext && !mDNSSameIPPort(rr->NATinfo.RequestedPort, port)); // I think this is always false -- SC Sept 07 - mDNSBool NATChanged = (!WereBehindNAT && NowNeedNATMAP) || (!NowNeedNATMAP && PortWasMapped); - - (void)HaveZoneData; //unused - - LogInfo("UpdateOneSRVRecord: Resource Record %s TargetChanged %d, NewTarget %##s", ARDisplayString(m, rr), TargetChanged, nt->c); - - debugf("UpdateOneSRVRecord: %##s newtarget %##s TargetChanged %d HaveZoneData %d port %d NowNeedNATMAP %d WereBehindNAT %d PortWasMapped %d NATChanged %d", - rr->resrec.name->c, newtarget, - TargetChanged, HaveZoneData, mDNSVal16(port), NowNeedNATMAP, WereBehindNAT, PortWasMapped, NATChanged); - - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("UpdateOneSRVRecord: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - if (!TargetChanged && !NATChanged) return; - - // If we are deregistering the record, then ignore any NAT/Target change. - if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) - { - LogInfo("UpdateOneSRVRecord: Deregistering record, Ignoring TargetChanged %d, NATChanged %d for %##s, state %d", TargetChanged, NATChanged, - rr->resrec.name->c, rr->state); - return; - } - - if (newtarget) - LogInfo("UpdateOneSRVRecord: TargetChanged %d, NATChanged %d for %##s, state %d, newtarget %##s", TargetChanged, NATChanged, rr->resrec.name->c, rr->state, newtarget->c); - else - LogInfo("UpdateOneSRVRecord: TargetChanged %d, NATChanged %d for %##s, state %d, null newtarget", TargetChanged, NATChanged, rr->resrec.name->c, rr->state); - switch(rr->state) - { - case regState_NATMap: - // In these states, the SRV has either not yet been registered (it will get up-to-date information when it is) - // or is in the process of, or has already been, deregistered. This assumes that whenever we transition out - // of this state, we need to look at the target again. - return; - - case regState_UpdatePending: - // We are getting a Target change/NAT change while the SRV record is being updated ? - // let us not do anything for now. - return; - - case regState_NATError: - if (!NATChanged) return; - // if nat changed, register if we have a target (below) - - case regState_NoTarget: - if (!newtarget->c[0]) - { - LogInfo("UpdateOneSRVRecord: No target yet for Resource Record %s", ARDisplayString(m, rr)); - return; - } - RegisterAllServiceRecords(m , rr); - return; - case regState_DeregPending: - // We are in DeregPending either because the service was deregistered from above or we handled - // a NAT/Target change before and sent the deregistration below. There are a few race conditions - // possible - // - // 1. We are handling a second NAT/Target change while the first dereg is in progress. It is possible - // that first dereg never made it through because there was no network connectivity e.g., disconnecting - // from network triggers this function due to a target change and later connecting to the network - // retriggers this function but the deregistration never made it through yet. Just fall through. - // If there is a target register otherwise deregister. - // - // 2. While we sent the dereg during a previous NAT/Target change, uDNS_DeregisterRecord gets - // called as part of service deregistration. When the response comes back, we call - // CompleteDeregistration rather than handle NAT/Target change because the record is in - // kDNSRecordTypeDeregistering state. - // - // 3. If the upper layer deregisters the service, we check for kDNSRecordTypeDeregistering both - // here in this function to avoid handling NAT/Target change and in hndlRecordUpdateReply to call - // CompleteDeregistration instead of handling NAT/Target change. Hence, we are not concerned - // about that case here. - // - // We just handle case (1) by falling through - case regState_Pending: - case regState_Refresh: - case regState_Registered: - // target or nat changed. deregister service. upon completion, we'll look for a new target - rr->SRVChanged = mDNStrue; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - if (newtarget->c[0]) - { - LogInfo("UpdateOneSRVRecord: SRV record changed for service %##s, registering with new target %##s", - rr->resrec.name->c, newtarget->c); - rr->state = regState_Pending; - } - else - { - LogInfo("UpdateOneSRVRecord: SRV record changed for service %##s de-registering", rr->resrec.name->c); - rr->state = regState_DeregPending; - UpdateAllServiceRecords(m, rr, mDNSfalse); - } - return; - case regState_Unregistered: - default: LogMsg("UpdateOneSRVRecord: Unknown state %d for %##s", rr->state, rr->resrec.name->c); - } - } - -mDNSexport void UpdateAllSRVRecords(mDNS *m) - { - m->NextSRVUpdate = 0; - LogInfo("UpdateAllSRVRecords %d", m->SleepState); - - if (m->CurrentRecord) - LogMsg("UpdateAllSRVRecords ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); - m->CurrentRecord = m->ResourceRecords; - while (m->CurrentRecord) - { - AuthRecord *rptr = m->CurrentRecord; - m->CurrentRecord = m->CurrentRecord->next; - if (AuthRecord_uDNS(rptr) && rptr->resrec.rrtype == kDNSType_SRV) - UpdateOneSRVRecord(m, rptr); - } - } - -// Forward reference: AdvertiseHostname references HostnameCallback, and HostnameCallback calls AdvertiseHostname -mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result); - -// Called in normal client context (lock not held) -mDNSlocal void hostnameGetPublicAddressCallback(mDNS *m, NATTraversalInfo *n) - { - HostnameInfo *h = (HostnameInfo *)n->clientContext; - - if (!h) { LogMsg("RegisterHostnameRecord: registration cancelled"); return; } - - if (!n->Result) - { - if (mDNSIPv4AddressIsZero(n->ExternalAddress) || mDNSv4AddrIsRFC1918(&n->ExternalAddress)) return; - - if (h->arv4.resrec.RecordType) - { - if (mDNSSameIPv4Address(h->arv4.resrec.rdata->u.ipv4, n->ExternalAddress)) return; // If address unchanged, do nothing - LogInfo("Updating hostname %p %##s IPv4 from %.4a to %.4a (NAT gateway's external address)",n, - h->arv4.resrec.name->c, &h->arv4.resrec.rdata->u.ipv4, &n->ExternalAddress); - mDNS_Deregister(m, &h->arv4); // mStatus_MemFree callback will re-register with new address - } - else - { - LogInfo("Advertising hostname %##s IPv4 %.4a (NAT gateway's external address)", h->arv4.resrec.name->c, &n->ExternalAddress); - h->arv4.resrec.RecordType = kDNSRecordTypeKnownUnique; - h->arv4.resrec.rdata->u.ipv4 = n->ExternalAddress; - mDNS_Register(m, &h->arv4); - } - } - } - -// register record or begin NAT traversal -mDNSlocal void AdvertiseHostname(mDNS *m, HostnameInfo *h) - { - if (!mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4) && h->arv4.resrec.RecordType == kDNSRecordTypeUnregistered) - { - mDNS_SetupResourceRecord(&h->arv4, mDNSNULL, mDNSInterface_Any, kDNSType_A, kHostNameTTL, kDNSRecordTypeUnregistered, AuthRecordAny, HostnameCallback, h); - AssignDomainName(&h->arv4.namestorage, &h->fqdn); - h->arv4.resrec.rdata->u.ipv4 = m->AdvertisedV4.ip.v4; - h->arv4.state = regState_Unregistered; - if (mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4)) - { - // If we already have a NAT query active, stop it and restart it to make sure we get another callback - if (h->natinfo.clientContext) mDNS_StopNATOperation_internal(m, &h->natinfo); - h->natinfo.Protocol = 0; - h->natinfo.IntPort = zeroIPPort; - h->natinfo.RequestedPort = zeroIPPort; - h->natinfo.NATLease = 0; - h->natinfo.clientCallback = hostnameGetPublicAddressCallback; - h->natinfo.clientContext = h; - mDNS_StartNATOperation_internal(m, &h->natinfo); - } - else - { - LogInfo("Advertising hostname %##s IPv4 %.4a", h->arv4.resrec.name->c, &m->AdvertisedV4.ip.v4); - h->arv4.resrec.RecordType = kDNSRecordTypeKnownUnique; - mDNS_Register_internal(m, &h->arv4); - } - } - - if (!mDNSIPv6AddressIsZero(m->AdvertisedV6.ip.v6) && h->arv6.resrec.RecordType == kDNSRecordTypeUnregistered) - { - mDNS_SetupResourceRecord(&h->arv6, mDNSNULL, mDNSInterface_Any, kDNSType_AAAA, kHostNameTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, HostnameCallback, h); - AssignDomainName(&h->arv6.namestorage, &h->fqdn); - h->arv6.resrec.rdata->u.ipv6 = m->AdvertisedV6.ip.v6; - h->arv6.state = regState_Unregistered; - LogInfo("Advertising hostname %##s IPv6 %.16a", h->arv6.resrec.name->c, &m->AdvertisedV6.ip.v6); - mDNS_Register_internal(m, &h->arv6); - } - } - -mDNSlocal void HostnameCallback(mDNS *const m, AuthRecord *const rr, mStatus result) - { - HostnameInfo *hi = (HostnameInfo *)rr->RecordContext; - - if (result == mStatus_MemFree) - { - if (hi) - { - // If we're still in the Hostnames list, update to new address - HostnameInfo *i; - LogInfo("HostnameCallback: Got mStatus_MemFree for %p %p %s", hi, rr, ARDisplayString(m, rr)); - for (i = m->Hostnames; i; i = i->next) - if (rr == &i->arv4 || rr == &i->arv6) - { mDNS_Lock(m); AdvertiseHostname(m, i); mDNS_Unlock(m); return; } - - // Else, we're not still in the Hostnames list, so free the memory - if (hi->arv4.resrec.RecordType == kDNSRecordTypeUnregistered && - hi->arv6.resrec.RecordType == kDNSRecordTypeUnregistered) - { - if (hi->natinfo.clientContext) mDNS_StopNATOperation_internal(m, &hi->natinfo); - hi->natinfo.clientContext = mDNSNULL; - mDNSPlatformMemFree(hi); // free hi when both v4 and v6 AuthRecs deallocated - } - } - return; - } - - if (result) - { - // don't unlink or free - we can retry when we get a new address/router - if (rr->resrec.rrtype == kDNSType_A) - LogMsg("HostnameCallback: Error %d for registration of %##s IP %.4a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv4); - else - LogMsg("HostnameCallback: Error %d for registration of %##s IP %.16a", result, rr->resrec.name->c, &rr->resrec.rdata->u.ipv6); - if (!hi) { mDNSPlatformMemFree(rr); return; } - if (rr->state != regState_Unregistered) LogMsg("Error: HostnameCallback invoked with error code for record not in regState_Unregistered!"); - - if (hi->arv4.state == regState_Unregistered && - hi->arv6.state == regState_Unregistered) - { - // only deliver status if both v4 and v6 fail - rr->RecordContext = (void *)hi->StatusContext; - if (hi->StatusCallback) - hi->StatusCallback(m, rr, result); // client may NOT make API calls here - rr->RecordContext = (void *)hi; - } - return; - } - - // register any pending services that require a target - mDNS_Lock(m); - m->NextSRVUpdate = NonZeroTime(m->timenow); - mDNS_Unlock(m); - - // Deliver success to client - if (!hi) { LogMsg("HostnameCallback invoked with orphaned address record"); return; } - if (rr->resrec.rrtype == kDNSType_A) - LogInfo("Registered hostname %##s IP %.4a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv4); - else - LogInfo("Registered hostname %##s IP %.16a", rr->resrec.name->c, &rr->resrec.rdata->u.ipv6); - - rr->RecordContext = (void *)hi->StatusContext; - if (hi->StatusCallback) - hi->StatusCallback(m, rr, result); // client may NOT make API calls here - rr->RecordContext = (void *)hi; - } - -mDNSlocal void FoundStaticHostname(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) - { - const domainname *pktname = &answer->rdata->u.name; - domainname *storedname = &m->StaticHostname; - HostnameInfo *h = m->Hostnames; - - (void)question; - - if (answer->rdlength != 0) - LogInfo("FoundStaticHostname: question %##s -> answer %##s (%s)", question->qname.c, answer->rdata->u.name.c, AddRecord ? "ADD" : "RMV"); - else - LogInfo("FoundStaticHostname: question %##s -> answer NULL (%s)", question->qname.c, AddRecord ? "ADD" : "RMV"); - - if (AddRecord && answer->rdlength != 0 && !SameDomainName(pktname, storedname)) - { - AssignDomainName(storedname, pktname); - while (h) - { - if (h->arv4.state == regState_Pending || h->arv4.state == regState_NATMap || h->arv6.state == regState_Pending) - { - // if we're in the process of registering a dynamic hostname, delay SRV update so we don't have to reregister services if the dynamic name succeeds - m->NextSRVUpdate = NonZeroTime(m->timenow + 5 * mDNSPlatformOneSecond); - debugf("FoundStaticHostname: NextSRVUpdate in %d %d", m->NextSRVUpdate - m->timenow, m->timenow); - return; - } - h = h->next; - } - mDNS_Lock(m); - m->NextSRVUpdate = NonZeroTime(m->timenow); - mDNS_Unlock(m); - } - else if (!AddRecord && SameDomainName(pktname, storedname)) - { - mDNS_Lock(m); - storedname->c[0] = 0; - m->NextSRVUpdate = NonZeroTime(m->timenow); - mDNS_Unlock(m); - } - } - -// Called with lock held -mDNSlocal void GetStaticHostname(mDNS *m) - { - char buf[MAX_REVERSE_MAPPING_NAME_V4]; - DNSQuestion *q = &m->ReverseMap; - mDNSu8 *ip = m->AdvertisedV4.ip.v4.b; - mStatus err; - - if (m->ReverseMap.ThisQInterval != -1) return; // already running - if (mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4)) return; - - mDNSPlatformMemZero(q, sizeof(*q)); - // Note: This is reverse order compared to a normal dotted-decimal IP address, so we can't use our customary "%.4a" format code - mDNS_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa.", ip[3], ip[2], ip[1], ip[0]); - if (!MakeDomainNameFromDNSNameString(&q->qname, buf)) { LogMsg("Error: GetStaticHostname - bad name %s", buf); return; } - - q->InterfaceID = mDNSInterface_Any; - q->Target = zeroAddr; - q->qtype = kDNSType_PTR; - q->qclass = kDNSClass_IN; - q->LongLived = mDNSfalse; - q->ExpectUnique = mDNSfalse; - q->ForceMCast = mDNSfalse; - q->ReturnIntermed = mDNStrue; - q->SuppressUnusable = mDNSfalse; - q->SearchListIndex = 0; - q->AppendSearchDomains = 0; - q->RetryWithSearchDomains = mDNSfalse; - q->TimeoutQuestion = 0; - q->WakeOnResolve = 0; - q->qnameOrig = mDNSNULL; - q->QuestionCallback = FoundStaticHostname; - q->QuestionContext = mDNSNULL; - - LogInfo("GetStaticHostname: %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - err = mDNS_StartQuery_internal(m, q); - if (err) LogMsg("Error: GetStaticHostname - StartQuery returned error %d", err); - } - -mDNSexport void mDNS_AddDynDNSHostName(mDNS *m, const domainname *fqdn, mDNSRecordCallback *StatusCallback, const void *StatusContext) - { - HostnameInfo **ptr = &m->Hostnames; - - LogInfo("mDNS_AddDynDNSHostName %##s", fqdn); - - while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next; - if (*ptr) { LogMsg("DynDNSHostName %##s already in list", fqdn->c); return; } - - // allocate and format new address record - *ptr = mDNSPlatformMemAllocate(sizeof(**ptr)); - if (!*ptr) { LogMsg("ERROR: mDNS_AddDynDNSHostName - malloc"); return; } - - mDNSPlatformMemZero(*ptr, sizeof(**ptr)); - AssignDomainName(&(*ptr)->fqdn, fqdn); - (*ptr)->arv4.state = regState_Unregistered; - (*ptr)->arv6.state = regState_Unregistered; - (*ptr)->StatusCallback = StatusCallback; - (*ptr)->StatusContext = StatusContext; - - AdvertiseHostname(m, *ptr); - } - -mDNSexport void mDNS_RemoveDynDNSHostName(mDNS *m, const domainname *fqdn) - { - HostnameInfo **ptr = &m->Hostnames; - - LogInfo("mDNS_RemoveDynDNSHostName %##s", fqdn); - - while (*ptr && !SameDomainName(fqdn, &(*ptr)->fqdn)) ptr = &(*ptr)->next; - if (!*ptr) LogMsg("mDNS_RemoveDynDNSHostName: no such domainname %##s", fqdn->c); - else - { - HostnameInfo *hi = *ptr; - // We do it this way because, if we have no active v6 record, the "mDNS_Deregister_internal(m, &hi->arv4);" - // below could free the memory, and we have to make sure we don't touch hi fields after that. - mDNSBool f4 = hi->arv4.resrec.RecordType != kDNSRecordTypeUnregistered && hi->arv4.state != regState_Unregistered; - mDNSBool f6 = hi->arv6.resrec.RecordType != kDNSRecordTypeUnregistered && hi->arv6.state != regState_Unregistered; - if (f4) LogInfo("mDNS_RemoveDynDNSHostName removing v4 %##s", fqdn); - if (f6) LogInfo("mDNS_RemoveDynDNSHostName removing v6 %##s", fqdn); - *ptr = (*ptr)->next; // unlink - if (f4) mDNS_Deregister_internal(m, &hi->arv4, mDNS_Dereg_normal); - if (f6) mDNS_Deregister_internal(m, &hi->arv6, mDNS_Dereg_normal); - // When both deregistrations complete we'll free the memory in the mStatus_MemFree callback - } - if (!m->mDNS_busy) LogMsg("mDNS_RemoveDynDNSHostName: ERROR: Lock not held"); - m->NextSRVUpdate = NonZeroTime(m->timenow); - } - -// Currently called without holding the lock -// Maybe we should change that? -mDNSexport void mDNS_SetPrimaryInterfaceInfo(mDNS *m, const mDNSAddr *v4addr, const mDNSAddr *v6addr, const mDNSAddr *router) - { - mDNSBool v4Changed, v6Changed, RouterChanged; - - if (m->mDNS_busy != m->mDNS_reentrancy) - LogMsg("mDNS_SetPrimaryInterfaceInfo: mDNS_busy (%ld) != mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - if (v4addr && v4addr->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo v4 address - incorrect type. Discarding. %#a", v4addr); return; } - if (v6addr && v6addr->type != mDNSAddrType_IPv6) { LogMsg("mDNS_SetPrimaryInterfaceInfo v6 address - incorrect type. Discarding. %#a", v6addr); return; } - if (router && router->type != mDNSAddrType_IPv4) { LogMsg("mDNS_SetPrimaryInterfaceInfo passed non-v4 router. Discarding. %#a", router); return; } - - mDNS_Lock(m); - - v4Changed = !mDNSSameIPv4Address(m->AdvertisedV4.ip.v4, v4addr ? v4addr->ip.v4 : zerov4Addr); - v6Changed = !mDNSSameIPv6Address(m->AdvertisedV6.ip.v6, v6addr ? v6addr->ip.v6 : zerov6Addr); - RouterChanged = !mDNSSameIPv4Address(m->Router.ip.v4, router ? router->ip.v4 : zerov4Addr); - - if (v4addr && (v4Changed || RouterChanged)) - debugf("mDNS_SetPrimaryInterfaceInfo: address changed from %#a to %#a", &m->AdvertisedV4, v4addr); - - if (v4addr) m->AdvertisedV4 = *v4addr; else m->AdvertisedV4.ip.v4 = zerov4Addr; - if (v6addr) m->AdvertisedV6 = *v6addr; else m->AdvertisedV6.ip.v6 = zerov6Addr; - if (router) m->Router = *router; else m->Router .ip.v4 = zerov4Addr; - // setting router to zero indicates that nat mappings must be reestablished when router is reset - - if (v4Changed || RouterChanged || v6Changed) - { - HostnameInfo *i; - LogInfo("mDNS_SetPrimaryInterfaceInfo: %s%s%s%#a %#a %#a", - v4Changed ? "v4Changed " : "", - RouterChanged ? "RouterChanged " : "", - v6Changed ? "v6Changed " : "", v4addr, v6addr, router); - - for (i = m->Hostnames; i; i = i->next) - { - LogInfo("mDNS_SetPrimaryInterfaceInfo updating host name registrations for %##s", i->fqdn.c); - - if (i->arv4.resrec.RecordType > kDNSRecordTypeDeregistering && - !mDNSSameIPv4Address(i->arv4.resrec.rdata->u.ipv4, m->AdvertisedV4.ip.v4)) - { - LogInfo("mDNS_SetPrimaryInterfaceInfo deregistering %s", ARDisplayString(m, &i->arv4)); - mDNS_Deregister_internal(m, &i->arv4, mDNS_Dereg_normal); - } - - if (i->arv6.resrec.RecordType > kDNSRecordTypeDeregistering && - !mDNSSameIPv6Address(i->arv6.resrec.rdata->u.ipv6, m->AdvertisedV6.ip.v6)) - { - LogInfo("mDNS_SetPrimaryInterfaceInfo deregistering %s", ARDisplayString(m, &i->arv6)); - mDNS_Deregister_internal(m, &i->arv6, mDNS_Dereg_normal); - } - - // AdvertiseHostname will only register new address records. - // For records still in the process of deregistering it will ignore them, and let the mStatus_MemFree callback handle them. - AdvertiseHostname(m, i); - } - - if (v4Changed || RouterChanged) - { - // If we have a non-zero IPv4 address, we should try immediately to see if we have a NAT gateway - // If we have no IPv4 address, we don't want to be in quite such a hurry to report failures to our clients - // <rdar://problem/6935929> Sleeping server sometimes briefly disappears over Back to My Mac after it wakes up - m->ExternalAddress = zerov4Addr; - m->retryIntervalGetAddr = NATMAP_INIT_RETRY; - m->retryGetAddr = m->timenow + (v4addr ? 0 : mDNSPlatformOneSecond * 5); - m->NextScheduledNATOp = m->timenow; - m->LastNATMapResultCode = NATErr_None; -#ifdef _LEGACY_NAT_TRAVERSAL_ - LNT_ClearState(m); -#endif // _LEGACY_NAT_TRAVERSAL_ - LogInfo("mDNS_SetPrimaryInterfaceInfo:%s%s: retryGetAddr in %d %d", - v4Changed ? " v4Changed" : "", - RouterChanged ? " RouterChanged" : "", - m->retryGetAddr - m->timenow, m->timenow); - } - - if (m->ReverseMap.ThisQInterval != -1) mDNS_StopQuery_internal(m, &m->ReverseMap); - m->StaticHostname.c[0] = 0; - - m->NextSRVUpdate = NonZeroTime(m->timenow); - -#if APPLE_OSX_mDNSResponder - if (RouterChanged) uuid_generate(m->asl_uuid); - UpdateAutoTunnelDomainStatuses(m); -#endif - } - - mDNS_Unlock(m); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Incoming Message Processing -#endif - -mDNSlocal mStatus ParseTSIGError(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const domainname *const displayname) - { - const mDNSu8 *ptr; - mStatus err = mStatus_NoError; - int i; - - ptr = LocateAdditionals(msg, end); - if (!ptr) goto finish; - - for (i = 0; i < msg->h.numAdditionals; i++) - { - ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); - if (!ptr) goto finish; - if (m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative && m->rec.r.resrec.rrtype == kDNSType_TSIG) - { - mDNSu32 macsize; - mDNSu8 *rd = m->rec.r.resrec.rdata->u.data; - mDNSu8 *rdend = rd + m->rec.r.resrec.rdlength; - int alglen = DomainNameLengthLimit(&m->rec.r.resrec.rdata->u.name, rdend); - if (alglen > MAX_DOMAIN_NAME) goto finish; - rd += alglen; // algorithm name - if (rd + 6 > rdend) goto finish; - rd += 6; // 48-bit timestamp - if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; - rd += sizeof(mDNSOpaque16); // fudge - if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; - macsize = mDNSVal16(*(mDNSOpaque16 *)rd); - rd += sizeof(mDNSOpaque16); // MAC size - if (rd + macsize > rdend) goto finish; - rd += macsize; - if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; - rd += sizeof(mDNSOpaque16); // orig id - if (rd + sizeof(mDNSOpaque16) > rdend) goto finish; - err = mDNSVal16(*(mDNSOpaque16 *)rd); // error code - - if (err == TSIG_ErrBadSig) { LogMsg("%##s: bad signature", displayname->c); err = mStatus_BadSig; } - else if (err == TSIG_ErrBadKey) { LogMsg("%##s: bad key", displayname->c); err = mStatus_BadKey; } - else if (err == TSIG_ErrBadTime) { LogMsg("%##s: bad time", displayname->c); err = mStatus_BadTime; } - else if (err) { LogMsg("%##s: unknown tsig error %d", displayname->c, err); err = mStatus_UnknownErr; } - goto finish; - } - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - } - - finish: - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - return err; - } - -mDNSlocal mStatus checkUpdateResult(mDNS *const m, const domainname *const displayname, const mDNSu8 rcode, const DNSMessage *const msg, const mDNSu8 *const end) - { - (void)msg; // currently unused, needed for TSIG errors - if (!rcode) return mStatus_NoError; - else if (rcode == kDNSFlag1_RC_YXDomain) - { - debugf("name in use: %##s", displayname->c); - return mStatus_NameConflict; - } - else if (rcode == kDNSFlag1_RC_Refused) - { - LogMsg("Update %##s refused", displayname->c); - return mStatus_Refused; - } - else if (rcode == kDNSFlag1_RC_NXRRSet) - { - LogMsg("Reregister refused (NXRRSET): %##s", displayname->c); - return mStatus_NoSuchRecord; - } - else if (rcode == kDNSFlag1_RC_NotAuth) - { - // TSIG errors should come with FormErr as per RFC 2845, but BIND 9 sends them with NotAuth so we look here too - mStatus tsigerr = ParseTSIGError(m, msg, end, displayname); - if (!tsigerr) - { - LogMsg("Permission denied (NOAUTH): %##s", displayname->c); - return mStatus_UnknownErr; - } - else return tsigerr; - } - else if (rcode == kDNSFlag1_RC_FormErr) - { - mStatus tsigerr = ParseTSIGError(m, msg, end, displayname); - if (!tsigerr) - { - LogMsg("Format Error: %##s", displayname->c); - return mStatus_UnknownErr; - } - else return tsigerr; - } - else - { - LogMsg("Update %##s failed with rcode %d", displayname->c, rcode); - return mStatus_UnknownErr; - } - } - -// We add three Additional Records for unicast resource record registrations -// which is a function of AuthInfo and AutoTunnel properties -mDNSlocal mDNSu32 RRAdditionalSize(mDNS *const m, DomainAuthInfo *AuthInfo) - { - mDNSu32 leaseSize, hinfoSize, tsigSize; - mDNSu32 rr_base_size = 10; // type (2) class (2) TTL (4) rdlength (2) - - // OPT RR : Emptyname(.) + base size + rdataOPT - leaseSize = 1 + rr_base_size + sizeof(rdataOPT); - - // HINFO: Resource Record Name + base size + RDATA - // HINFO is added only for autotunnels - hinfoSize = 0; - if (AuthInfo && AuthInfo->AutoTunnel) - hinfoSize = (m->hostlabel.c[0] + 1) + DomainNameLength(&AuthInfo->domain) + - rr_base_size + (2 + m->HIHardware.c[0] + m->HISoftware.c[0]); - - //TSIG: Resource Record Name + base size + RDATA - // RDATA: - // Algorithm name: hmac-md5.sig-alg.reg.int (8+7+3+3 + 5 bytes for length = 26 bytes) - // Time: 6 bytes - // Fudge: 2 bytes - // Mac Size: 2 bytes - // Mac: 16 bytes - // ID: 2 bytes - // Error: 2 bytes - // Len: 2 bytes - // Total: 58 bytes - tsigSize = 0; - if (AuthInfo) tsigSize = DomainNameLength(&AuthInfo->keyname) + rr_base_size + 58; - - return (leaseSize + hinfoSize + tsigSize); - } - -//Note: Make sure that RREstimatedSize is updated accordingly if anything that is done here -//would modify rdlength/rdestimate -mDNSlocal mDNSu8* BuildUpdateMessage(mDNS *const m, mDNSu8 *ptr, AuthRecord *rr, mDNSu8 *limit) - { - //If this record is deregistering, then just send the deletion record - if (rr->state == regState_DeregPending) - { - rr->expire = 0; // Indicate that we have no active registration any more - ptr = putDeletionRecordWithLimit(&m->omsg, ptr, &rr->resrec, limit); - if (!ptr) goto exit; - return ptr; - } - - // This is a common function to both sending an update in a group or individual - // records separately. Hence, we change the state here. - if (rr->state == regState_Registered) rr->state = regState_Refresh; - if (rr->state != regState_Refresh && rr->state != regState_UpdatePending) - rr->state = regState_Pending; - - // For Advisory records like e.g., _services._dns-sd, which is shared, don't send goodbyes as multiple - // host might be registering records and deregistering from one does not make sense - if (rr->resrec.RecordType != kDNSRecordTypeAdvisory) rr->RequireGoodbye = mDNStrue; - - if ((rr->resrec.rrtype == kDNSType_SRV) && (rr->AutoTarget == Target_AutoHostAndNATMAP) && - !mDNSIPPortIsZero(rr->NATinfo.ExternalPort)) - { - rr->resrec.rdata->u.srv.port = rr->NATinfo.ExternalPort; - } - - if (rr->state == regState_UpdatePending) - { - // delete old RData - SetNewRData(&rr->resrec, rr->OrigRData, rr->OrigRDLen); - if (!(ptr = putDeletionRecordWithLimit(&m->omsg, ptr, &rr->resrec, limit))) goto exit; // delete old rdata - - // add new RData - SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); - if (!(ptr = PutResourceRecordTTLWithLimit(&m->omsg, ptr, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit))) goto exit; - } - else - { - if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique || rr->resrec.RecordType == kDNSRecordTypeVerified) - { - // KnownUnique : Delete any previous value - // For Unicast registrations, we don't verify that it is unique, but set to verified and hence we want to - // delete any previous value - ptr = putDeleteRRSetWithLimit(&m->omsg, ptr, rr->resrec.name, rr->resrec.rrtype, limit); - if (!ptr) goto exit; - } - else if (rr->resrec.RecordType != kDNSRecordTypeShared) - { - // For now don't do this, until we have the logic for intelligent grouping of individual records into logical service record sets - //ptr = putPrereqNameNotInUse(rr->resrec.name, &m->omsg, ptr, end); - if (!ptr) goto exit; - } - - ptr = PutResourceRecordTTLWithLimit(&m->omsg, ptr, &m->omsg.h.mDNS_numUpdates, &rr->resrec, rr->resrec.rroriginalttl, limit); - if (!ptr) goto exit; - } - - return ptr; -exit: - LogMsg("BuildUpdateMessage: Error formatting message for %s", ARDisplayString(m, rr)); - return mDNSNULL; - } - -// Called with lock held -mDNSlocal void SendRecordRegistration(mDNS *const m, AuthRecord *rr) - { - mDNSu8 *ptr = m->omsg.data; - mStatus err = mStatus_UnknownErr; - mDNSu8 *limit; - DomainAuthInfo *AuthInfo; - - // For the ability to register large TXT records, we limit the single record registrations - // to AbsoluteMaxDNSMessageData - limit = ptr + AbsoluteMaxDNSMessageData; - - AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); - limit -= RRAdditionalSize(m, AuthInfo); - - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("SendRecordRegistration: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) - { - // We never call this function when there is no zone information . Log a message if it ever happens. - LogMsg("SendRecordRegistration: No Zone information, should not happen %s", ARDisplayString(m, rr)); - return; - } - - rr->updateid = mDNS_NewMessageID(m); - InitializeDNSMessage(&m->omsg.h, rr->updateid, UpdateReqFlags); - - // set zone - ptr = putZone(&m->omsg, ptr, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); - if (!ptr) goto exit; - - if (!(ptr = BuildUpdateMessage(m, ptr, rr, limit))) goto exit; - - if (rr->uselease) - { - ptr = putUpdateLeaseWithLimit(&m->omsg, ptr, DEFAULT_UPDATE_LEASE, limit); - if (!ptr) goto exit; - } - if (rr->Private) - { - LogInfo("SendRecordRegistration TCP %p %s", rr->tcp, ARDisplayString(m, rr)); - if (rr->tcp) LogInfo("SendRecordRegistration: Disposing existing TCP connection for %s", ARDisplayString(m, rr)); - if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } - if (!rr->nta) { LogMsg("SendRecordRegistration:Private:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } - rr->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &rr->nta->Addr, rr->nta->Port, &rr->nta->Host, mDNSNULL, rr); - } - else - { - LogInfo("SendRecordRegistration UDP %s", ARDisplayString(m, rr)); - if (!rr->nta) { LogMsg("SendRecordRegistration:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } - err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, &rr->nta->Addr, rr->nta->Port, mDNSNULL, GetAuthInfoForName_internal(m, rr->resrec.name)); - if (err) debugf("ERROR: SendRecordRegistration - mDNSSendDNSMessage - %d", err); - } - - SetRecordRetry(m, rr, 0); - return; -exit: - LogMsg("SendRecordRegistration: Error formatting message for %s, disabling further updates", ARDisplayString(m, rr)); - // Disable this record from future updates - rr->state = regState_NoTarget; - } - -// Is the given record "rr" eligible for merging ? -mDNSlocal mDNSBool IsRecordMergeable(mDNS *const m, AuthRecord *rr, mDNSs32 time) - { - DomainAuthInfo *info; - (void) m; //unused - // A record is eligible for merge, if the following properties are met. - // - // 1. uDNS Resource Record - // 2. It is time to send them now - // 3. It is in proper state - // 4. Update zone has been resolved - // 5. if DomainAuthInfo exists for the zone, it should not be soon deleted - // 6. Zone information is present - // 7. Update server is not zero - // 8. It has a non-null zone - // 9. It uses a lease option - // 10. DontMerge is not set - // - // Following code is implemented as separate "if" statements instead of one "if" statement - // is for better debugging purposes e.g., we know exactly what failed if debugging turned on. - - if (!AuthRecord_uDNS(rr)) return mDNSfalse; - - if (rr->LastAPTime + rr->ThisAPInterval - time > 0) - { debugf("IsRecordMergeable: Time %d not reached for %s", rr->LastAPTime + rr->ThisAPInterval - m->timenow, ARDisplayString(m, rr)); return mDNSfalse; } - - if (!rr->zone) return mDNSfalse; - - info = GetAuthInfoForName_internal(m, rr->zone); - - if (info && info->deltime && m->timenow - info->deltime >= 0) {debugf("IsRecordMergeable: Domain %##s will be deleted soon", info->domain.c); return mDNSfalse;} - - if (rr->state != regState_DeregPending && rr->state != regState_Pending && rr->state != regState_Registered && rr->state != regState_Refresh && rr->state != regState_UpdatePending) - { debugf("IsRecordMergeable: state %d not right %s", rr->state, ARDisplayString(m, rr)); return mDNSfalse; } - - if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) return mDNSfalse; - - if (!rr->uselease) return mDNSfalse; - - if (rr->mState == mergeState_DontMerge) {debugf("IsRecordMergeable Dontmerge true %s", ARDisplayString(m, rr));return mDNSfalse;} - debugf("IsRecordMergeable: Returning true for %s", ARDisplayString(m, rr)); - return mDNStrue; - } - -// Is the resource record "rr" eligible to merge to with "currentRR" ? -mDNSlocal mDNSBool AreRecordsMergeable(mDNS *const m, AuthRecord *currentRR, AuthRecord *rr, mDNSs32 time) - { - // A record is eligible to merge with another record as long it is eligible for merge in itself - // and it has the same zone information as the other record - if (!IsRecordMergeable(m, rr, time)) return mDNSfalse; - - if (!SameDomainName(currentRR->zone, rr->zone)) - { debugf("AreRecordMergeable zone mismatch current rr Zone %##s, rr zone %##s", currentRR->zone->c, rr->zone->c); return mDNSfalse; } - - if (!mDNSSameIPv4Address(currentRR->nta->Addr.ip.v4, rr->nta->Addr.ip.v4)) return mDNSfalse; - - if (!mDNSSameIPPort(currentRR->nta->Port, rr->nta->Port)) return mDNSfalse; - - debugf("AreRecordsMergeable: Returning true for %s", ARDisplayString(m, rr)); - return mDNStrue; - } - -// If we can't build the message successfully because of problems in pre-computing -// the space, we disable merging for all the current records -mDNSlocal void RRMergeFailure(mDNS *const m) - { - AuthRecord *rr; - for (rr = m->ResourceRecords; rr; rr = rr->next) - { - rr->mState = mergeState_DontMerge; - rr->SendRNow = mDNSNULL; - // Restarting the registration is much simpler than saving and restoring - // the exact time - ActivateUnicastRegistration(m, rr); - } - } - -mDNSlocal void SendGroupRRMessage(mDNS *const m, AuthRecord *anchorRR, mDNSu8 *ptr, DomainAuthInfo *info) - { - mDNSu8 *limit; - if (!anchorRR) {debugf("SendGroupRRMessage: Could not merge records"); return;} - - if (info && info->AutoTunnel) limit = m->omsg.data + AbsoluteMaxDNSMessageData; - else limit = m->omsg.data + NormalMaxDNSMessageData; - - // This has to go in the additional section and hence need to be done last - ptr = putUpdateLeaseWithLimit(&m->omsg, ptr, DEFAULT_UPDATE_LEASE, limit); - if (!ptr) - { - LogMsg("SendGroupRRMessage: ERROR: Could not put lease option, failing the group registration"); - // if we can't put the lease, we need to undo the merge - RRMergeFailure(m); - return; - } - if (anchorRR->Private) - { - if (anchorRR->tcp) debugf("SendGroupRRMessage: Disposing existing TCP connection for %s", ARDisplayString(m, anchorRR)); - if (anchorRR->tcp) { DisposeTCPConn(anchorRR->tcp); anchorRR->tcp = mDNSNULL; } - if (!anchorRR->nta) { LogMsg("SendGroupRRMessage:ERROR!! nta is NULL for %s", ARDisplayString(m, anchorRR)); return; } - anchorRR->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &anchorRR->nta->Addr, anchorRR->nta->Port, &anchorRR->nta->Host, mDNSNULL, anchorRR); - if (!anchorRR->tcp) LogInfo("SendGroupRRMessage: Cannot establish TCP connection for %s", ARDisplayString(m, anchorRR)); - else LogInfo("SendGroupRRMessage: Sent a group update ID: %d start %p, end %p, limit %p", mDNSVal16(m->omsg.h.id), m->omsg.data, ptr, limit); - } - else - { - mStatus err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, &anchorRR->nta->Addr, anchorRR->nta->Port, mDNSNULL, info); - if (err) LogInfo("SendGroupRRMessage: Cannot send UDP message for %s", ARDisplayString(m, anchorRR)); - else LogInfo("SendGroupRRMessage: Sent a group UDP update ID: %d start %p, end %p, limit %p", mDNSVal16(m->omsg.h.id), m->omsg.data, ptr, limit); - } - return; - } - -// As we always include the zone information and the resource records contain zone name -// at the end, it will get compressed. Hence, we subtract zoneSize and add two bytes for -// the compression pointer -mDNSlocal mDNSu32 RREstimatedSize(AuthRecord *rr, int zoneSize) - { - int rdlength; - - // Note: Estimation of the record size has to mirror the logic in BuildUpdateMessage, otherwise estimation - // would be wrong. Currently BuildUpdateMessage calls SetNewRData in UpdatePending case. Hence, we need - // to account for that here. Otherwise, we might under estimate the size. - if (rr->state == regState_UpdatePending) - // old RData that will be deleted - // new RData that will be added - rdlength = rr->OrigRDLen + rr->InFlightRDLen; - else - rdlength = rr->resrec.rdestimate; - - if (rr->state == regState_DeregPending) - { - debugf("RREstimatedSize: ResourceRecord %##s (%s), DomainNameLength %d, zoneSize %d, rdestimate %d", - rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), DomainNameLength(rr->resrec.name), zoneSize, rdlength); - return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + rdlength; - } - - // For SRV, TXT, AAAA etc. that are Unique/Verified, we also send a Deletion Record - if (rr->resrec.RecordType == kDNSRecordTypeKnownUnique || rr->resrec.RecordType == kDNSRecordTypeVerified) - { - // Deletion Record: Resource Record Name + Base size (10) + 0 - // Record: Resource Record Name (Compressed = 2) + Base size (10) + rdestimate - - debugf("RREstimatedSize: ResourceRecord %##s (%s), DomainNameLength %d, zoneSize %d, rdestimate %d", - rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), DomainNameLength(rr->resrec.name), zoneSize, rdlength); - return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + 2 + 10 + rdlength; - } - else - { - return DomainNameLength(rr->resrec.name) - zoneSize + 2 + 10 + rdlength; - } - } - -mDNSlocal AuthRecord *MarkRRForSending(mDNS *const m) - { - AuthRecord *rr; - AuthRecord *firstRR = mDNSNULL; - - // Look for records that needs to be sent in the next two seconds (MERGE_DELAY_TIME is set to 1 second). - // The logic is as follows. - // - // 1. Record 1 finishes getting zone data and its registration gets delayed by 1 second - // 2. Record 2 comes 0.1 second later, finishes getting its zone data and its registration is also delayed by - // 1 second which is now scheduled at 1.1 second - // - // By looking for 1 second into the future (m->timenow + MERGE_DELAY_TIME below does that) we have merged both - // of the above records. Note that we can't look for records too much into the future as this will affect the - // retry logic. The first retry is scheduled at 3 seconds. Hence, we should always look smaller than that. - // Anything more than one second will affect the first retry to happen sooner. - // - // Note: As a side effect of looking one second into the future to facilitate merging, the retries happen - // one second sooner. - for (rr = m->ResourceRecords; rr; rr = rr->next) - { - if (!firstRR) - { - if (!IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) continue; - firstRR = rr; - } - else if (!AreRecordsMergeable(m, firstRR, rr, m->timenow + MERGE_DELAY_TIME)) continue; - - if (rr->SendRNow) LogMsg("MarkRRForSending: Resourcerecord %s already marked for sending", ARDisplayString(m, rr)); - rr->SendRNow = mDNSInterfaceMark; - } - - // We parsed through all records and found something to send. The services/records might - // get registered at different times but we want the refreshes to be all merged and sent - // as one update. Hence, we accelerate some of the records so that they will sync up in - // the future. Look at the records excluding the ones that we have already sent in the - // previous pass. If it half way through its scheduled refresh/retransmit, merge them - // into this packet. - // - // Note that we only look at Registered/Refresh state to keep it simple. As we don't know - // whether the current update will fit into one or more packets, merging a resource record - // (which is in a different state) that has been scheduled for retransmit would trigger - // sending more packets. - if (firstRR) - { - int acc = 0; - for (rr = m->ResourceRecords; rr; rr = rr->next) - { - if ((rr->state != regState_Registered && rr->state != regState_Refresh) || - (rr->SendRNow == mDNSInterfaceMark) || - (!AreRecordsMergeable(m, firstRR, rr, m->timenow + rr->ThisAPInterval/2))) - continue; - rr->SendRNow = mDNSInterfaceMark; - acc++; - } - if (acc) LogInfo("MarkRRForSending: Accelereated %d records", acc); - } - return firstRR; - } - -mDNSlocal mDNSBool SendGroupUpdates(mDNS *const m) - { - mDNSOpaque16 msgid; - mDNSs32 spaceleft = 0; - mDNSs32 zoneSize, rrSize; - mDNSu8 *oldnext; // for debugging - mDNSu8 *next = m->omsg.data; - AuthRecord *rr; - AuthRecord *anchorRR = mDNSNULL; - int nrecords = 0; - AuthRecord *startRR = m->ResourceRecords; - mDNSu8 *limit = mDNSNULL; - DomainAuthInfo *AuthInfo = mDNSNULL; - mDNSBool sentallRecords = mDNStrue; - - - // We try to fit as many ResourceRecords as possible in AbsoluteNormal/MaxDNSMessageData. Before we start - // putting in resource records, we need to reserve space for a few things. Every group/packet should - // have the following. - // - // 1) Needs space for the Zone information (which needs to be at the beginning) - // 2) Additional section MUST have space for lease option, HINFO and TSIG option (which needs to - // to be at the end) - // - // In future we need to reserve space for the pre-requisites which also goes at the beginning. - // To accomodate pre-requisites in the future, first we walk the whole list marking records - // that can be sent in this packet and computing the space needed for these records. - // For TXT and SRV records, we delete the previous record if any by sending the same - // resource record with ANY RDATA and zero rdlen. Hence, we need to have space for both of them. - - while (startRR) - { - AuthInfo = mDNSNULL; - anchorRR = mDNSNULL; - nrecords = 0; - zoneSize = 0; - for (rr = startRR; rr; rr = rr->next) - { - if (rr->SendRNow != mDNSInterfaceMark) continue; - - rr->SendRNow = mDNSNULL; - - if (!anchorRR) - { - AuthInfo = GetAuthInfoForName_internal(m, rr->zone); - - // Though we allow single record registrations for UDP to be AbsoluteMaxDNSMessageData (See - // SendRecordRegistration) to handle large TXT records, to avoid fragmentation we limit UDP - // message to NormalMaxDNSMessageData - if (AuthInfo && AuthInfo->AutoTunnel) spaceleft = AbsoluteMaxDNSMessageData; - else spaceleft = NormalMaxDNSMessageData; - - next = m->omsg.data; - spaceleft -= RRAdditionalSize(m, AuthInfo); - if (spaceleft <= 0) - { - LogMsg("SendGroupUpdates: ERROR!!: spaceleft is zero at the beginning"); - RRMergeFailure(m); - return mDNSfalse; - } - limit = next + spaceleft; - - // Build the initial part of message before putting in the other records - msgid = mDNS_NewMessageID(m); - InitializeDNSMessage(&m->omsg.h, msgid, UpdateReqFlags); - - // We need zone information at the beginning of the packet. Length: ZNAME, ZTYPE(2), ZCLASS(2) - // zone has to be non-NULL for a record to be mergeable, hence it is safe to set/ examine zone - //without checking for NULL. - zoneSize = DomainNameLength(rr->zone) + 4; - spaceleft -= zoneSize; - if (spaceleft <= 0) - { - LogMsg("SendGroupUpdates: ERROR no space for zone information, disabling merge"); - RRMergeFailure(m); - return mDNSfalse; - } - next = putZone(&m->omsg, next, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); - if (!next) - { - LogMsg("SendGroupUpdates: ERROR! Cannot put zone, disabling merge"); - RRMergeFailure(m); - return mDNSfalse; - } - anchorRR = rr; - } - - rrSize = RREstimatedSize(rr, zoneSize - 4); - - if ((spaceleft - rrSize) < 0) - { - // If we can't fit even a single message, skip it, it will be sent separately - // in CheckRecordUpdates - if (!nrecords) - { - LogInfo("SendGroupUpdates: Skipping message %s, spaceleft %d, rrSize %d", ARDisplayString(m, rr), spaceleft, rrSize); - // Mark this as not sent so that the caller knows about it - rr->SendRNow = mDNSInterfaceMark; - // We need to remove the merge delay so that we can send it immediately - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - rr = rr->next; - anchorRR = mDNSNULL; - sentallRecords = mDNSfalse; - } - else - { - LogInfo("SendGroupUpdates:1: Parsed %d records and sending using %s, spaceleft %d, rrSize %d", nrecords, ARDisplayString(m, anchorRR), spaceleft, rrSize); - SendGroupRRMessage(m, anchorRR, next, AuthInfo); - } - break; // breaks out of for loop - } - spaceleft -= rrSize; - oldnext = next; - LogInfo("SendGroupUpdates: Building a message with resource record %s, next %p, state %d, ttl %d", ARDisplayString(m, rr), next, rr->state, rr->resrec.rroriginalttl); - if (!(next = BuildUpdateMessage(m, next, rr, limit))) - { - // We calculated the space and if we can't fit in, we had some bug in the calculation, - // disable merge completely. - LogMsg("SendGroupUpdates: ptr NULL while building message with %s", ARDisplayString(m, rr)); - RRMergeFailure(m); - return mDNSfalse; - } - // If our estimate was higher, adjust to the actual size - if ((next - oldnext) > rrSize) - LogMsg("SendGroupUpdates: ERROR!! Record size estimation is wrong for %s, Estimate %d, Actual %d, state %d", ARDisplayString(m, rr), rrSize, next - oldnext, rr->state); - else { spaceleft += rrSize; spaceleft -= (next - oldnext); } - - nrecords++; - // We could have sent an update earlier with this "rr" as anchorRR for which we never got a response. - // To preserve ordering, we blow away the previous connection before sending this. - if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL;} - rr->updateid = msgid; - - // By setting the retry time interval here, we will not be looking at these records - // again when we return to CheckGroupRecordUpdates. - SetRecordRetry(m, rr, 0); - } - // Either we have parsed all the records or stopped at "rr" above due to lack of space - startRR = rr; - } - - if (anchorRR) - { - LogInfo("SendGroupUpdates: Parsed %d records and sending using %s", nrecords, ARDisplayString(m, anchorRR)); - SendGroupRRMessage(m, anchorRR, next, AuthInfo); - } - return sentallRecords; - } - -// Merge the record registrations and send them as a group only if they -// have same DomainAuthInfo and hence the same key to put the TSIG -mDNSlocal void CheckGroupRecordUpdates(mDNS *const m) - { - AuthRecord *rr, *nextRR; - // Keep sending as long as there is at least one record to be sent - while (MarkRRForSending(m)) - { - if (!SendGroupUpdates(m)) - { - // if everything that was marked was not sent, send them out individually - for (rr = m->ResourceRecords; rr; rr = nextRR) - { - // SendRecordRegistrtion might delete the rr from list, hence - // dereference nextRR before calling the function - nextRR = rr->next; - if (rr->SendRNow == mDNSInterfaceMark) - { - // Any records marked for sending should be eligible to be sent out - // immediately. Just being cautious - if (rr->LastAPTime + rr->ThisAPInterval - m->timenow > 0) - { LogMsg("CheckGroupRecordUpdates: ERROR!! Resourcerecord %s not ready", ARDisplayString(m, rr)); continue; } - rr->SendRNow = mDNSNULL; - SendRecordRegistration(m, rr); - } - } - } - } - - debugf("CheckGroupRecordUpdates: No work, returning"); - return; - } - -mDNSlocal void hndlSRVChanged(mDNS *const m, AuthRecord *rr) - { - // Reevaluate the target always as NAT/Target could have changed while - // we were registering/deeregistering - domainname *dt; - const domainname *target = GetServiceTarget(m, rr); - if (!target || target->c[0] == 0) - { - // we don't have a target, if we just derregistered, then we don't have to do anything - if (rr->state == regState_DeregPending) - { - LogInfo("hndlSRVChanged: SRVChanged, No Target, SRV Deregistered for %##s, state %d", rr->resrec.name->c, - rr->state); - rr->SRVChanged = mDNSfalse; - dt = GetRRDomainNameTarget(&rr->resrec); - if (dt) dt->c[0] = 0; - rr->state = regState_NoTarget; // Wait for the next target change - rr->resrec.rdlength = rr->resrec.rdestimate = 0; - return; - } - - // we don't have a target, if we just registered, we need to deregister - if (rr->state == regState_Pending) - { - LogInfo("hndlSRVChanged: SRVChanged, No Target, Deregistering again %##s, state %d", rr->resrec.name->c, rr->state); - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - rr->state = regState_DeregPending; - return; - } - LogInfo("hndlSRVChanged: Not in DeregPending or RegPending state %##s, state %d", rr->resrec.name->c, rr->state); - } - else - { - // If we were in registered state and SRV changed to NULL, we deregister and come back here - // if we have a target, we need to register again. - // - // if we just registered check to see if it is same. If it is different just re-register the - // SRV and its assoicated records - // - // UpdateOneSRVRecord takes care of re-registering all service records - if ((rr->state == regState_DeregPending) || - (rr->state == regState_Pending && !SameDomainName(target, &rr->resrec.rdata->u.srv.target))) - { - dt = GetRRDomainNameTarget(&rr->resrec); - if (dt) dt->c[0] = 0; - rr->state = regState_NoTarget; // NoTarget will allow us to pick up new target OR nat traversal state - rr->resrec.rdlength = rr->resrec.rdestimate = 0; - LogInfo("hndlSRVChanged: SRVChanged, Valid Target %##s, Registering all records for %##s, state %d", - target->c, rr->resrec.name->c, rr->state); - rr->SRVChanged = mDNSfalse; - UpdateOneSRVRecord(m, rr); - return; - } - // Target did not change while this record was registering. Hence, we go to - // Registered state - the state we started from. - if (rr->state == regState_Pending) rr->state = regState_Registered; - } - - rr->SRVChanged = mDNSfalse; - } - -// Called with lock held -mDNSlocal void hndlRecordUpdateReply(mDNS *m, AuthRecord *rr, mStatus err, mDNSu32 random) - { - mDNSBool InvokeCallback = mDNStrue; - mDNSIPPort UpdatePort = zeroIPPort; - - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("hndlRecordUpdateReply: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - LogInfo("hndlRecordUpdateReply: err %d ID %d state %d %s(%p)", err, mDNSVal16(rr->updateid), rr->state, ARDisplayString(m, rr), rr); - - rr->updateError = err; -#if APPLE_OSX_mDNSResponder - if (err == mStatus_BadSig) UpdateAutoTunnelDomainStatuses(m); -#endif - - SetRecordRetry(m, rr, random); - - rr->updateid = zeroID; // Make sure that this is not considered as part of a group anymore - // Later when need to send an update, we will get the zone data again. Thus we avoid - // using stale information. - // - // Note: By clearing out the zone info here, it also helps better merging of records - // in some cases. For example, when we get out regState_NoTarget state e.g., move out - // of Double NAT, we want all the records to be in one update. Some BTMM records like - // _autotunnel6 and host records are registered/deregistered when NAT state changes. - // As they are re-registered the zone information is cleared out. To merge with other - // records that might be possibly going out, clearing out the information here helps - // as all of them try to get the zone data. - if (rr->nta) - { - // We always expect the question to be stopped when we get a valid response from the server. - // If the zone info tries to change during this time, updateid would be different and hence - // this response should not have been accepted. - if (rr->nta->question.ThisQInterval != -1) - LogMsg("hndlRecordUpdateReply: ResourceRecord %s, zone info question %##s (%s) interval %d not -1", - ARDisplayString(m, rr), rr->nta->question.qname.c, DNSTypeName(rr->nta->question.qtype), rr->nta->question.ThisQInterval); - UpdatePort = rr->nta->Port; - CancelGetZoneData(m, rr->nta); - rr->nta = mDNSNULL; - } - - // If we are deregistering the record, then complete the deregistration. Ignore any NAT/SRV change - // that could have happened during that time. - if (rr->resrec.RecordType == kDNSRecordTypeDeregistering && rr->state == regState_DeregPending) - { - debugf("hndlRecordUpdateReply: Received reply for deregister record %##s type %d", rr->resrec.name->c, rr->resrec.rrtype); - if (err) LogMsg("ERROR: Deregistration of record %##s type %d failed with error %d", - rr->resrec.name->c, rr->resrec.rrtype, err); - rr->state = regState_Unregistered; - CompleteDeregistration(m, rr); - return; - } - - // We are returning early without updating the state. When we come back from sleep we will re-register after - // re-initializing all the state as though it is a first registration. If the record can't be registered e.g., - // no target, it will be deregistered. Hence, the updating to the right state should not matter when going - // to sleep. - if (m->SleepState) - { - // Need to set it to NoTarget state so that RecordReadyForSleep knows that - // we are done - if (rr->resrec.rrtype == kDNSType_SRV && rr->state == regState_DeregPending) - rr->state = regState_NoTarget; - return; - } - - if (rr->state == regState_UpdatePending) - { - if (err) LogMsg("Update record failed for %##s (err %d)", rr->resrec.name->c, err); - rr->state = regState_Registered; - // deallocate old RData - if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->OrigRData, rr->OrigRDLen); - SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); - rr->OrigRData = mDNSNULL; - rr->InFlightRData = mDNSNULL; - } - - if (rr->SRVChanged) - { - if (rr->resrec.rrtype == kDNSType_SRV) - hndlSRVChanged(m, rr); - else - { - LogInfo("hndlRecordUpdateReply: Deregistered %##s (%s), state %d", rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype), rr->state); - rr->SRVChanged = mDNSfalse; - if (rr->state != regState_DeregPending) LogMsg("hndlRecordUpdateReply: ResourceRecord %s not in DeregPending state %d", ARDisplayString(m, rr), rr->state); - rr->state = regState_NoTarget; // Wait for the next target change - } - return; - } - - if (rr->state == regState_Pending || rr->state == regState_Refresh) - { - if (!err) - { - if (rr->state == regState_Refresh) InvokeCallback = mDNSfalse; - rr->state = regState_Registered; - } - else - { - // Retry without lease only for non-Private domains - LogMsg("hndlRecordUpdateReply: Registration of record %##s type %d failed with error %d", rr->resrec.name->c, rr->resrec.rrtype, err); - if (!rr->Private && rr->uselease && err == mStatus_UnknownErr && mDNSSameIPPort(UpdatePort, UnicastDNSPort)) - { - LogMsg("hndlRecordUpdateReply: Will retry update of record %##s without lease option", rr->resrec.name->c); - rr->uselease = mDNSfalse; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - return; - } - // Communicate the error to the application in the callback below - } - } - - if (rr->QueuedRData && rr->state == regState_Registered) - { - rr->state = regState_UpdatePending; - rr->InFlightRData = rr->QueuedRData; - rr->InFlightRDLen = rr->QueuedRDLen; - rr->OrigRData = rr->resrec.rdata; - rr->OrigRDLen = rr->resrec.rdlength; - rr->QueuedRData = mDNSNULL; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - return; - } - - // Don't invoke the callback on error as this may not be useful to the client. - // The client may potentially delete the resource record on error which we normally - // delete during deregistration - if (!err && InvokeCallback && rr->RecordCallback) - { - LogInfo("hndlRecordUpdateReply: Calling record callback on %##s", rr->resrec.name->c); - mDNS_DropLockBeforeCallback(); - rr->RecordCallback(m, rr, err); - mDNS_ReclaimLockAfterCallback(); - } - // CAUTION: MUST NOT do anything more with rr after calling rr->Callback(), because the client's callback function - // is allowed to do anything, including starting/stopping queries, registering/deregistering records, etc. - } - -mDNSexport void uDNS_ReceiveNATPMPPacket(mDNS *m, const mDNSInterfaceID InterfaceID, mDNSu8 *pkt, mDNSu16 len) - { - NATTraversalInfo *ptr; - NATAddrReply *AddrReply = (NATAddrReply *)pkt; - NATPortMapReply *PortMapReply = (NATPortMapReply *)pkt; - mDNSu32 nat_elapsed, our_elapsed; - - // Minimum packet is vers (1) opcode (1) err (2) upseconds (4) = 8 bytes - if (!AddrReply->err && len < 8) { LogMsg("NAT Traversal message too short (%d bytes)", len); return; } - if (AddrReply->vers != NATMAP_VERS) { LogMsg("Received NAT Traversal response with version %d (expected %d)", pkt[0], NATMAP_VERS); return; } - - // Read multi-byte numeric values (fields are identical in a NATPortMapReply) - AddrReply->err = (mDNSu16) ( (mDNSu16)pkt[2] << 8 | pkt[3]); - AddrReply->upseconds = (mDNSs32) ((mDNSs32)pkt[4] << 24 | (mDNSs32)pkt[5] << 16 | (mDNSs32)pkt[6] << 8 | pkt[7]); - - nat_elapsed = AddrReply->upseconds - m->LastNATupseconds; - our_elapsed = (m->timenow - m->LastNATReplyLocalTime) / mDNSPlatformOneSecond; - debugf("uDNS_ReceiveNATPMPPacket %X upseconds %u nat_elapsed %d our_elapsed %d", AddrReply->opcode, AddrReply->upseconds, nat_elapsed, our_elapsed); - - // We compute a conservative estimate of how much the NAT gateways's clock should have advanced - // 1. We subtract 12.5% from our own measured elapsed time, to allow for NAT gateways that have an inacurate clock that runs slowly - // 2. We add a two-second safety margin to allow for rounding errors: e.g. - // -- if NAT gateway sends a packet at t=2.000 seconds, then one at t=7.999, that's approximately 6 real seconds, - // but based on the values in the packet (2,7) the apparent difference according to the packet is only 5 seconds - // -- if we're slow handling packets and/or we have coarse clock granularity, - // we could receive the t=2 packet at our t=1.999 seconds, which we round down to 1 - // and the t=7.999 packet at our t=8.000 seconds, which we record as 8, - // giving an apparent local time difference of 7 seconds - // The two-second safety margin coves this possible calculation discrepancy - if (AddrReply->upseconds < m->LastNATupseconds || nat_elapsed + 2 < our_elapsed - our_elapsed/8) - { LogMsg("NAT gateway %#a rebooted", &m->Router); RecreateNATMappings(m); } - - m->LastNATupseconds = AddrReply->upseconds; - m->LastNATReplyLocalTime = m->timenow; -#ifdef _LEGACY_NAT_TRAVERSAL_ - LNT_ClearState(m); -#endif // _LEGACY_NAT_TRAVERSAL_ - - if (AddrReply->opcode == NATOp_AddrResponse) - { -#if APPLE_OSX_mDNSResponder - static char msgbuf[16]; - mDNS_snprintf(msgbuf, sizeof(msgbuf), "%d", AddrReply->err); - mDNSASLLog((uuid_t *)&m->asl_uuid, "natt.natpmp.AddressRequest", AddrReply->err ? "failure" : "success", msgbuf, ""); -#endif - if (!AddrReply->err && len < sizeof(NATAddrReply)) { LogMsg("NAT Traversal AddrResponse message too short (%d bytes)", len); return; } - natTraversalHandleAddressReply(m, AddrReply->err, AddrReply->ExtAddr); - } - else if (AddrReply->opcode == NATOp_MapUDPResponse || AddrReply->opcode == NATOp_MapTCPResponse) - { - mDNSu8 Protocol = AddrReply->opcode & 0x7F; -#if APPLE_OSX_mDNSResponder - static char msgbuf[16]; - mDNS_snprintf(msgbuf, sizeof(msgbuf), "%s - %d", AddrReply->opcode == NATOp_MapUDPResponse ? "UDP" : "TCP", PortMapReply->err); - mDNSASLLog((uuid_t *)&m->asl_uuid, "natt.natpmp.PortMapRequest", PortMapReply->err ? "failure" : "success", msgbuf, ""); -#endif - if (!PortMapReply->err) - { - if (len < sizeof(NATPortMapReply)) { LogMsg("NAT Traversal PortMapReply message too short (%d bytes)", len); return; } - PortMapReply->NATRep_lease = (mDNSu32) ((mDNSu32)pkt[12] << 24 | (mDNSu32)pkt[13] << 16 | (mDNSu32)pkt[14] << 8 | pkt[15]); - } - - // Since some NAT-PMP server implementations don't return the requested internal port in - // the reply, we can't associate this reply with a particular NATTraversalInfo structure. - // We globally keep track of the most recent error code for mappings. - m->LastNATMapResultCode = PortMapReply->err; - - for (ptr = m->NATTraversals; ptr; ptr=ptr->next) - if (ptr->Protocol == Protocol && mDNSSameIPPort(ptr->IntPort, PortMapReply->intport)) - natTraversalHandlePortMapReply(m, ptr, InterfaceID, PortMapReply->err, PortMapReply->extport, PortMapReply->NATRep_lease); - } - else { LogMsg("Received NAT Traversal response with version unknown opcode 0x%X", AddrReply->opcode); return; } - - // Don't need an SSDP socket if we get a NAT-PMP packet - if (m->SSDPSocket) { debugf("uDNS_ReceiveNATPMPPacket destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } - } - -// <rdar://problem/3925163> Shorten DNS-SD queries to avoid NAT bugs -// <rdar://problem/4288449> Add check to avoid crashing NAT gateways that have buggy DNS relay code -// -// We know of bugs in home NAT gateways that cause them to crash if they receive certain DNS queries. -// The DNS queries that make them crash are perfectly legal DNS queries, but even if they weren't, -// the gateway shouldn't crash -- in today's world of viruses and network attacks, software has to -// be written assuming that a malicious attacker could send them any packet, properly-formed or not. -// Still, we don't want to be crashing people's home gateways, so we go out of our way to avoid -// the queries that crash them. -// -// Some examples: -// -// 1. Any query where the name ends in ".in-addr.arpa." and the text before this is 32 or more bytes. -// The query type does not need to be PTR -- the gateway will crash for any query type. -// e.g. "ping long-name-crashes-the-buggy-router.in-addr.arpa" will crash one of these. -// -// 2. Any query that results in a large response with the TC bit set. -// -// 3. Any PTR query that doesn't begin with four decimal numbers. -// These gateways appear to assume that the only possible PTR query is a reverse-mapping query -// (e.g. "1.0.168.192.in-addr.arpa") and if they ever get a PTR query where the first four -// labels are not all decimal numbers in the range 0-255, they handle that by crashing. -// These gateways also ignore the remainder of the name following the four decimal numbers -// -- whether or not it actually says in-addr.arpa, they just make up an answer anyway. -// -// The challenge therefore is to craft a query that will discern whether the DNS server -// is one of these buggy ones, without crashing it. Furthermore we don't want our test -// queries making it all the way to the root name servers, putting extra load on those -// name servers and giving Apple a bad reputation. To this end we send this query: -// dig -t ptr 1.0.0.127.dnsbugtest.1.0.0.127.in-addr.arpa. -// -// The text preceding the ".in-addr.arpa." is under 32 bytes, so it won't cause crash (1). -// It will not yield a large response with the TC bit set, so it won't cause crash (2). -// It starts with four decimal numbers, so it won't cause crash (3). -// The name falls within the "1.0.0.127.in-addr.arpa." domain, the reverse-mapping name for the local -// loopback address, and therefore the query will black-hole at the first properly-configured DNS server -// it reaches, making it highly unlikely that this query will make it all the way to the root. -// -// Finally, the correct response to this query is NXDOMAIN or a similar error, but the -// gateways that ignore the remainder of the name following the four decimal numbers -// give themselves away by actually returning a result for this nonsense query. - -mDNSlocal const domainname *DNSRelayTestQuestion = (const domainname*) - "\x1" "1" "\x1" "0" "\x1" "0" "\x3" "127" "\xa" "dnsbugtest" - "\x1" "1" "\x1" "0" "\x1" "0" "\x3" "127" "\x7" "in-addr" "\x4" "arpa"; - -// See comments above for DNSRelayTestQuestion -// If this is the kind of query that has the risk of crashing buggy DNS servers, we do a test question first -mDNSlocal mDNSBool NoTestQuery(DNSQuestion *q) - { - int i; - mDNSu8 *p = q->qname.c; - if (q->AuthInfo) return(mDNStrue); // Don't need a test query for private queries sent directly to authoritative server over TLS/TCP - if (q->qtype != kDNSType_PTR) return(mDNStrue); // Don't need a test query for any non-PTR queries - for (i=0; i<4; i++) // If qname does not begin with num.num.num.num, can't skip the test query - { - if (p[0] < 1 || p[0] > 3) return(mDNSfalse); - if ( p[1] < '0' || p[1] > '9' ) return(mDNSfalse); - if (p[0] >= 2 && (p[2] < '0' || p[2] > '9')) return(mDNSfalse); - if (p[0] >= 3 && (p[3] < '0' || p[3] > '9')) return(mDNSfalse); - p += 1 + p[0]; - } - // If remainder of qname is ".in-addr.arpa.", this is a vanilla reverse-mapping query and - // we can safely do it without needing a test query first, otherwise we need the test query. - return(SameDomainName((domainname*)p, (const domainname*)"\x7" "in-addr" "\x4" "arpa")); - } - -// Returns mDNStrue if response was handled -mDNSlocal mDNSBool uDNS_ReceiveTestQuestionResponse(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, - const mDNSAddr *const srcaddr, const mDNSIPPort srcport) - { - const mDNSu8 *ptr = msg->data; - DNSQuestion pktq; - DNSServer *s; - mDNSu32 result = 0; - - // 1. Find out if this is an answer to one of our test questions - if (msg->h.numQuestions != 1) return(mDNSfalse); - ptr = getQuestion(msg, ptr, end, mDNSInterface_Any, &pktq); - if (!ptr) return(mDNSfalse); - if (pktq.qtype != kDNSType_PTR || pktq.qclass != kDNSClass_IN) return(mDNSfalse); - if (!SameDomainName(&pktq.qname, DNSRelayTestQuestion)) return(mDNSfalse); - - // 2. If the DNS relay gave us a positive response, then it's got buggy firmware - // else, if the DNS relay gave us an error or no-answer response, it passed our test - if ((msg->h.flags.b[1] & kDNSFlag1_RC_Mask) == kDNSFlag1_RC_NoErr && msg->h.numAnswers > 0) - result = DNSServer_Failed; - else - result = DNSServer_Passed; - - // 3. Find occurrences of this server in our list, and mark them appropriately - for (s = m->DNSServers; s; s = s->next) - { - mDNSBool matchaddr = (s->teststate != result && mDNSSameAddress(srcaddr, &s->addr) && mDNSSameIPPort(srcport, s->port)); - mDNSBool matchid = (s->teststate == DNSServer_Untested && mDNSSameOpaque16(msg->h.id, s->testid)); - if (matchaddr || matchid) - { - DNSQuestion *q; - s->teststate = result; - if (result == DNSServer_Passed) - { - LogInfo("DNS Server %#a:%d (%#a:%d) %d passed%s", - &s->addr, mDNSVal16(s->port), srcaddr, mDNSVal16(srcport), mDNSVal16(s->testid), - matchaddr ? "" : " NOTE: Reply did not come from address to which query was sent"); - } - else - { - LogMsg("NOTE: Wide-Area Service Discovery disabled to avoid crashing defective DNS relay %#a:%d (%#a:%d) %d%s", - &s->addr, mDNSVal16(s->port), srcaddr, mDNSVal16(srcport), mDNSVal16(s->testid), - matchaddr ? "" : " NOTE: Reply did not come from address to which query was sent"); - } - - // If this server has just changed state from DNSServer_Untested to DNSServer_Passed, then retrigger any waiting questions. - // We use the NoTestQuery() test so that we only retrigger questions that were actually blocked waiting for this test to complete. - if (result == DNSServer_Passed) // Unblock any questions that were waiting for this result - for (q = m->Questions; q; q=q->next) - if (q->qDNSServer == s && !NoTestQuery(q)) - { - q->ThisQInterval = INIT_UCAST_POLL_INTERVAL / QuestionIntervalStep; - q->unansweredQueries = 0; - q->LastQTime = m->timenow - q->ThisQInterval; - m->NextScheduledQuery = m->timenow; - } - } - } - - return(mDNStrue); // Return mDNStrue to tell uDNS_ReceiveMsg it doesn't need to process this packet further - } - -// Called from mDNSCoreReceive with the lock held -mDNSexport void uDNS_ReceiveMsg(mDNS *const m, DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *const srcaddr, const mDNSIPPort srcport) - { - DNSQuestion *qptr; - mStatus err = mStatus_NoError; - - mDNSu8 StdR = kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery; - mDNSu8 UpdateR = kDNSFlag0_QR_Response | kDNSFlag0_OP_Update; - mDNSu8 QR_OP = (mDNSu8)(msg->h.flags.b[0] & kDNSFlag0_QROP_Mask); - mDNSu8 rcode = (mDNSu8)(msg->h.flags.b[1] & kDNSFlag1_RC_Mask); - - (void)srcport; // Unused - - debugf("uDNS_ReceiveMsg from %#-15a with " - "%2d Question%s %2d Answer%s %2d Authorit%s %2d Additional%s %d bytes", - srcaddr, - msg->h.numQuestions, msg->h.numQuestions == 1 ? ", " : "s,", - msg->h.numAnswers, msg->h.numAnswers == 1 ? ", " : "s,", - msg->h.numAuthorities, msg->h.numAuthorities == 1 ? "y, " : "ies,", - msg->h.numAdditionals, msg->h.numAdditionals == 1 ? "" : "s", end - msg->data); - - if (QR_OP == StdR) - { - //if (srcaddr && recvLLQResponse(m, msg, end, srcaddr, srcport)) return; - if (uDNS_ReceiveTestQuestionResponse(m, msg, end, srcaddr, srcport)) return; - for (qptr = m->Questions; qptr; qptr = qptr->next) - if (msg->h.flags.b[0] & kDNSFlag0_TC && mDNSSameOpaque16(qptr->TargetQID, msg->h.id) && m->timenow - qptr->LastQTime < RESPONSE_WINDOW) - { - if (!srcaddr) LogMsg("uDNS_ReceiveMsg: TCP DNS response had TC bit set: ignoring"); - else - { - // Don't reuse TCP connections. We might have failed over to a different DNS server - // while the first TCP connection is in progress. We need a new TCP connection to the - // new DNS server. So, always try to establish a new connection. - if (qptr->tcp) { DisposeTCPConn(qptr->tcp); qptr->tcp = mDNSNULL; } - qptr->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_Zero, srcaddr, srcport, mDNSNULL, qptr, mDNSNULL); - } - } - } - - if (QR_OP == UpdateR) - { - mDNSu32 lease = GetPktLease(m, msg, end); - mDNSs32 expire = m->timenow + (mDNSs32)lease * mDNSPlatformOneSecond; - mDNSu32 random = mDNSRandom((mDNSs32)lease * mDNSPlatformOneSecond/10); - - //rcode = kDNSFlag1_RC_ServFail; // Simulate server failure (rcode 2) - - // Walk through all the records that matches the messageID. There could be multiple - // records if we had sent them in a group - if (m->CurrentRecord) - LogMsg("uDNS_ReceiveMsg ERROR m->CurrentRecord already set %s", ARDisplayString(m, m->CurrentRecord)); - m->CurrentRecord = m->ResourceRecords; - while (m->CurrentRecord) - { - AuthRecord *rptr = m->CurrentRecord; - m->CurrentRecord = m->CurrentRecord->next; - if (AuthRecord_uDNS(rptr) && mDNSSameOpaque16(rptr->updateid, msg->h.id)) - { - err = checkUpdateResult(m, rptr->resrec.name, rcode, msg, end); - if (!err && rptr->uselease && lease) - if (rptr->expire - expire >= 0 || rptr->state != regState_UpdatePending) - { - rptr->expire = expire; - rptr->refreshCount = 0; - } - // We pass the random value to make sure that if we update multiple - // records, they all get the same random value - hndlRecordUpdateReply(m, rptr, err, random); - } - } - } - debugf("Received unexpected response: ID %d matches no active records", mDNSVal16(msg->h.id)); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Query Routines -#endif - -mDNSexport void sendLLQRefresh(mDNS *m, DNSQuestion *q) - { - mDNSu8 *end; - LLQOptData llq; - mDNSu8 *limit = m->omsg.data + AbsoluteMaxDNSMessageData; - - if (q->ReqLease) - if ((q->state == LLQ_Established && q->ntries >= kLLQ_MAX_TRIES) || q->expire - m->timenow < 0) - { - LogMsg("Unable to refresh LLQ %##s (%s) - will retry in %d seconds", q->qname.c, DNSTypeName(q->qtype), LLQ_POLL_INTERVAL / mDNSPlatformOneSecond); - StartLLQPolling(m,q); - return; - } - - llq.vers = kLLQ_Vers; - llq.llqOp = kLLQOp_Refresh; - llq.err = q->tcp ? GetLLQEventPort(m, &q->servAddr) : LLQErr_NoError; // If using TCP tell server what UDP port to send notifications to - llq.id = q->id; - llq.llqlease = q->ReqLease; - - InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); - end = putLLQ(&m->omsg, m->omsg.data, q, &llq); - if (!end) { LogMsg("sendLLQRefresh: putLLQ failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } - - // Note that we (conditionally) add HINFO and TSIG here, since the question might be going away, - // so we may not be able to reference it (most importantly it's AuthInfo) when we actually send the message - end = putHINFO(m, &m->omsg, end, q->AuthInfo, limit); - if (!end) { LogMsg("sendLLQRefresh: putHINFO failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } - - if (PrivateQuery(q)) - { - DNSDigest_SignMessageHostByteOrder(&m->omsg, &end, q->AuthInfo); - if (!end) { LogMsg("sendLLQRefresh: DNSDigest_SignMessage failed %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } - } - - if (PrivateQuery(q) && !q->tcp) - { - LogInfo("sendLLQRefresh setting up new TLS session %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - if (!q->nta) { LogMsg("sendLLQRefresh:ERROR!! q->nta is NULL for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } - q->tcp = MakeTCPConn(m, &m->omsg, end, kTCPSocketFlags_UseTLS, &q->servAddr, q->servPort, &q->nta->Host, q, mDNSNULL); - } - else - { - mStatus err; - - // if AuthInfo and AuthInfo->AutoTunnel is set, we use the TCP socket but don't need to pass the AuthInfo as - // we already protected the message above. - LogInfo("sendLLQRefresh: using existing %s session %##s (%s)", PrivateQuery(q) ? "TLS" : "UDP", - q->qname.c, DNSTypeName(q->qtype)); - - err = mDNSSendDNSMessage(m, &m->omsg, end, mDNSInterface_Any, q->LocalSocket, &q->servAddr, q->servPort, q->tcp ? q->tcp->sock : mDNSNULL, mDNSNULL); - if (err) - { - LogMsg("sendLLQRefresh: mDNSSendDNSMessage%s failed: %d", q->tcp ? " (TCP)" : "", err); - if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } - } - } - - q->ntries++; - - debugf("sendLLQRefresh ntries %d %##s (%s)", q->ntries, q->qname.c, DNSTypeName(q->qtype)); - - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - } - -mDNSexport void LLQGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo) - { - DNSQuestion *q = (DNSQuestion *)zoneInfo->ZoneDataContext; - - mDNS_Lock(m); - - // If we get here it means that the GetZoneData operation has completed. - // We hold on to the zone data if it is AutoTunnel as we use the hostname - // in zoneInfo during the TLS connection setup. - q->servAddr = zeroAddr; - q->servPort = zeroIPPort; - - if (!err && zoneInfo && !mDNSIPPortIsZero(zoneInfo->Port) && !mDNSAddressIsZero(&zoneInfo->Addr) && zoneInfo->Host.c[0]) - { - q->servAddr = zoneInfo->Addr; - q->servPort = zoneInfo->Port; - if (!PrivateQuery(q)) - { - // We don't need the zone data as we use it only for the Host information which we - // don't need if we are not going to use TLS connections. - if (q->nta) - { - if (q->nta != zoneInfo) LogMsg("LLQGotZoneData: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); - CancelGetZoneData(m, q->nta); - q->nta = mDNSNULL; - } - } - q->ntries = 0; - debugf("LLQGotZoneData %#a:%d", &q->servAddr, mDNSVal16(q->servPort)); - startLLQHandshake(m, q); - } - else - { - if (q->nta) - { - if (q->nta != zoneInfo) LogMsg("LLQGotZoneData: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); - CancelGetZoneData(m, q->nta); - q->nta = mDNSNULL; - } - StartLLQPolling(m,q); - if (err == mStatus_NoSuchNameErr) - { - // this actually failed, so mark it by setting address to all ones - q->servAddr.type = mDNSAddrType_IPv4; - q->servAddr.ip.v4 = onesIPv4Addr; - } - } - - mDNS_Unlock(m); - } - -// Called in normal callback context (i.e. mDNS_busy and mDNS_reentrancy are both 1) -mDNSlocal void PrivateQueryGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneInfo) - { - DNSQuestion *q = (DNSQuestion *) zoneInfo->ZoneDataContext; - - LogInfo("PrivateQueryGotZoneData %##s (%s) err %d Zone %##s Private %d", q->qname.c, DNSTypeName(q->qtype), err, zoneInfo->ZoneName.c, zoneInfo->ZonePrivate); - - if (q->nta != zoneInfo) LogMsg("PrivateQueryGotZoneData:ERROR!!: nta (%p) != zoneInfo (%p) %##s (%s)", q->nta, zoneInfo, q->qname.c, DNSTypeName(q->qtype)); - - if (err || !zoneInfo || mDNSAddressIsZero(&zoneInfo->Addr) || mDNSIPPortIsZero(zoneInfo->Port) || !zoneInfo->Host.c[0]) - { - LogInfo("PrivateQueryGotZoneData: ERROR!! %##s (%s) invoked with error code %d %p %#a:%d", - q->qname.c, DNSTypeName(q->qtype), err, zoneInfo, - zoneInfo ? &zoneInfo->Addr : mDNSNULL, - zoneInfo ? mDNSVal16(zoneInfo->Port) : 0); - CancelGetZoneData(m, q->nta); - q->nta = mDNSNULL; - return; - } - - if (!zoneInfo->ZonePrivate) - { - debugf("Private port lookup failed -- retrying without TLS -- %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - q->AuthInfo = mDNSNULL; // Clear AuthInfo so we try again non-private - q->ThisQInterval = InitialQuestionInterval; - q->LastQTime = m->timenow - q->ThisQInterval; - CancelGetZoneData(m, q->nta); - q->nta = mDNSNULL; - mDNS_Lock(m); - SetNextQueryTime(m, q); - mDNS_Unlock(m); - return; - // Next call to uDNS_CheckCurrentQuestion() will do this as a non-private query - } - - if (!PrivateQuery(q)) - { - LogMsg("PrivateQueryGotZoneData: ERROR!! Not a private query %##s (%s) AuthInfo %p", q->qname.c, DNSTypeName(q->qtype), q->AuthInfo); - CancelGetZoneData(m, q->nta); - q->nta = mDNSNULL; - return; - } - - q->TargetQID = mDNS_NewMessageID(m); - if (q->tcp) { DisposeTCPConn(q->tcp); q->tcp = mDNSNULL; } - if (!q->nta) { LogMsg("PrivateQueryGotZoneData:ERROR!! nta is NULL for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); return; } - q->tcp = MakeTCPConn(m, mDNSNULL, mDNSNULL, kTCPSocketFlags_UseTLS, &zoneInfo->Addr, zoneInfo->Port, &q->nta->Host, q, mDNSNULL); - if (q->nta) { CancelGetZoneData(m, q->nta); q->nta = mDNSNULL; } - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Dynamic Updates -#endif - -// Called in normal callback context (i.e. mDNS_busy and mDNS_reentrancy are both 1) -mDNSexport void RecordRegistrationGotZoneData(mDNS *const m, mStatus err, const ZoneData *zoneData) - { - AuthRecord *newRR = (AuthRecord*)zoneData->ZoneDataContext; - AuthRecord *ptr; - int c1, c2; - - if (newRR->nta != zoneData) - LogMsg("RecordRegistrationGotZoneData: nta (%p) != zoneData (%p) %##s (%s)", newRR->nta, zoneData, newRR->resrec.name->c, DNSTypeName(newRR->resrec.rrtype)); - - if (m->mDNS_busy != m->mDNS_reentrancy) - LogMsg("RecordRegistrationGotZoneData: mDNS_busy (%ld) != mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - // make sure record is still in list (!!!) - for (ptr = m->ResourceRecords; ptr; ptr = ptr->next) if (ptr == newRR) break; - if (!ptr) - { - LogMsg("RecordRegistrationGotZoneData - RR no longer in list. Discarding."); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - - // check error/result - if (err) - { - if (err != mStatus_NoSuchNameErr) LogMsg("RecordRegistrationGotZoneData: error %d", err); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - - if (!zoneData) { LogMsg("ERROR: RecordRegistrationGotZoneData invoked with NULL result and no error"); return; } - - if (newRR->resrec.rrclass != zoneData->ZoneClass) - { - LogMsg("ERROR: New resource record's class (%d) does not match zone class (%d)", newRR->resrec.rrclass, zoneData->ZoneClass); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - - // Don't try to do updates to the root name server. - // We might be tempted also to block updates to any single-label name server (e.g. com, edu, net, etc.) but some - // organizations use their own private pseudo-TLD, like ".home", etc, and we don't want to block that. - if (zoneData->ZoneName.c[0] == 0) - { - LogInfo("RecordRegistrationGotZoneData: No name server found claiming responsibility for \"%##s\"!", newRR->resrec.name->c); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - - // Store discovered zone data - c1 = CountLabels(newRR->resrec.name); - c2 = CountLabels(&zoneData->ZoneName); - if (c2 > c1) - { - LogMsg("RecordRegistrationGotZoneData: Zone \"%##s\" is longer than \"%##s\"", zoneData->ZoneName.c, newRR->resrec.name->c); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - newRR->zone = SkipLeadingLabels(newRR->resrec.name, c1-c2); - if (!SameDomainName(newRR->zone, &zoneData->ZoneName)) - { - LogMsg("RecordRegistrationGotZoneData: Zone \"%##s\" does not match \"%##s\" for \"%##s\"", newRR->zone->c, zoneData->ZoneName.c, newRR->resrec.name->c); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - - if (mDNSIPPortIsZero(zoneData->Port) || mDNSAddressIsZero(&zoneData->Addr) || !zoneData->Host.c[0]) - { - LogInfo("RecordRegistrationGotZoneData: No _dns-update._udp service found for \"%##s\"!", newRR->resrec.name->c); - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - - newRR->Private = zoneData->ZonePrivate; - debugf("RecordRegistrationGotZoneData: Set zone information for %##s %##s to %#a:%d", - newRR->resrec.name->c, zoneData->ZoneName.c, &zoneData->Addr, mDNSVal16(zoneData->Port)); - - // If we are deregistering, uDNS_DeregisterRecord will do that as it has the zone data now. - if (newRR->state == regState_DeregPending) - { - mDNS_Lock(m); - uDNS_DeregisterRecord(m, newRR); - mDNS_Unlock(m); - return; - } - - if (newRR->resrec.rrtype == kDNSType_SRV) - { - const domainname *target; - // Reevaluate the target always as NAT/Target could have changed while - // we were fetching zone data. - mDNS_Lock(m); - target = GetServiceTarget(m, newRR); - mDNS_Unlock(m); - if (!target || target->c[0] == 0) - { - domainname *t = GetRRDomainNameTarget(&newRR->resrec); - LogInfo("RecordRegistrationGotZoneData - no target for %##s", newRR->resrec.name->c); - if (t) t->c[0] = 0; - newRR->resrec.rdlength = newRR->resrec.rdestimate = 0; - newRR->state = regState_NoTarget; - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - } - // If we have non-zero service port (always?) - // and a private address, and update server is non-private - // and this service is AutoTarget - // then initiate a NAT mapping request. On completion it will do SendRecordRegistration() for us - if (newRR->resrec.rrtype == kDNSType_SRV && !mDNSIPPortIsZero(newRR->resrec.rdata->u.srv.port) && - mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4) && newRR->nta && !mDNSAddrIsRFC1918(&newRR->nta->Addr) && - newRR->AutoTarget == Target_AutoHostAndNATMAP) - { - DomainAuthInfo *AuthInfo; - AuthInfo = GetAuthInfoForName(m, newRR->resrec.name); - if (AuthInfo && AuthInfo->AutoTunnel) - { - domainname *t = GetRRDomainNameTarget(&newRR->resrec); - LogMsg("RecordRegistrationGotZoneData: ERROR!! AutoTunnel has Target_AutoHostAndNATMAP for %s", ARDisplayString(m, newRR)); - if (t) t->c[0] = 0; - newRR->resrec.rdlength = newRR->resrec.rdestimate = 0; - newRR->state = regState_NoTarget; - CancelGetZoneData(m, newRR->nta); - newRR->nta = mDNSNULL; - return; - } - // During network transitions, we are called multiple times in different states. Setup NAT - // state just once for this record. - if (!newRR->NATinfo.clientContext) - { - LogInfo("RecordRegistrationGotZoneData StartRecordNatMap %s", ARDisplayString(m, newRR)); - newRR->state = regState_NATMap; - StartRecordNatMap(m, newRR); - return; - } - else LogInfo("RecordRegistrationGotZoneData: StartRecordNatMap for %s, state %d, context %p", ARDisplayString(m, newRR), newRR->state, newRR->NATinfo.clientContext); - } - mDNS_Lock(m); - // We want IsRecordMergeable to check whether it is a record whose update can be - // sent with others. We set the time before we call IsRecordMergeable, so that - // it does not fail this record based on time. We are interested in other checks - // at this time. If a previous update resulted in error, then don't reset the - // interval. Preserve the back-off so that we don't keep retrying aggressively. - if (newRR->updateError == mStatus_NoError) - { - newRR->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - newRR->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - } - if (IsRecordMergeable(m, newRR, m->timenow + MERGE_DELAY_TIME)) - { - // Delay the record registration by MERGE_DELAY_TIME so that we can merge them - // into one update - LogInfo("RecordRegistrationGotZoneData: Delayed registration for %s", ARDisplayString(m, newRR)); - newRR->LastAPTime += MERGE_DELAY_TIME; - } - mDNS_Unlock(m); - } - -mDNSlocal void SendRecordDeregistration(mDNS *m, AuthRecord *rr) - { - mDNSu8 *ptr = m->omsg.data; - mDNSu8 *limit; - DomainAuthInfo *AuthInfo; - - if (m->mDNS_busy != m->mDNS_reentrancy+1) - LogMsg("SendRecordDeRegistration: Lock not held! mDNS_busy (%ld) mDNS_reentrancy (%ld)", m->mDNS_busy, m->mDNS_reentrancy); - - if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) - { - LogMsg("SendRecordDeRegistration: No zone info for Resource record %s RecordType %d", ARDisplayString(m, rr), rr->resrec.RecordType); - return; - } - - limit = ptr + AbsoluteMaxDNSMessageData; - AuthInfo = GetAuthInfoForName_internal(m, rr->resrec.name); - limit -= RRAdditionalSize(m, AuthInfo); - - rr->updateid = mDNS_NewMessageID(m); - InitializeDNSMessage(&m->omsg.h, rr->updateid, UpdateReqFlags); - - // set zone - ptr = putZone(&m->omsg, ptr, limit, rr->zone, mDNSOpaque16fromIntVal(rr->resrec.rrclass)); - if (!ptr) goto exit; - - ptr = BuildUpdateMessage(m, ptr, rr, limit); - - if (!ptr) goto exit; - - if (rr->Private) - { - LogInfo("SendRecordDeregistration TCP %p %s", rr->tcp, ARDisplayString(m, rr)); - if (rr->tcp) LogInfo("SendRecordDeregistration: Disposing existing TCP connection for %s", ARDisplayString(m, rr)); - if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } - if (!rr->nta) { LogMsg("SendRecordDeregistration:Private:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } - rr->tcp = MakeTCPConn(m, &m->omsg, ptr, kTCPSocketFlags_UseTLS, &rr->nta->Addr, rr->nta->Port, &rr->nta->Host, mDNSNULL, rr); - } - else - { - mStatus err; - LogInfo("SendRecordDeregistration UDP %s", ARDisplayString(m, rr)); - if (!rr->nta) { LogMsg("SendRecordDeregistration:ERROR!! nta is NULL for %s", ARDisplayString(m, rr)); return; } - err = mDNSSendDNSMessage(m, &m->omsg, ptr, mDNSInterface_Any, mDNSNULL, &rr->nta->Addr, rr->nta->Port, mDNSNULL, GetAuthInfoForName_internal(m, rr->resrec.name)); - if (err) debugf("ERROR: SendRecordDeregistration - mDNSSendDNSMessage - %d", err); - //if (rr->state == regState_DeregPending) CompleteDeregistration(m, rr); // Don't touch rr after this - } - SetRecordRetry(m, rr, 0); - return; -exit: - LogMsg("SendRecordDeregistration: Error formatting message for %s", ARDisplayString(m, rr)); - } - -mDNSexport mStatus uDNS_DeregisterRecord(mDNS *const m, AuthRecord *const rr) - { - DomainAuthInfo *info; - - LogInfo("uDNS_DeregisterRecord: Resource Record %s, state %d", ARDisplayString(m, rr), rr->state); - - switch (rr->state) - { - case regState_Refresh: - case regState_Pending: - case regState_UpdatePending: - case regState_Registered: break; - case regState_DeregPending: break; - - case regState_NATError: - case regState_NATMap: - // A record could be in NoTarget to start with if the corresponding SRV record could not find a target. - // It is also possible to reenter the NoTarget state when we move to a network with a NAT that has - // no NAT-PMP/UPnP support. In that case before we entered NoTarget, we already deregistered with - // the server. - case regState_NoTarget: - case regState_Unregistered: - case regState_Zero: - default: - LogInfo("uDNS_DeregisterRecord: State %d for %##s type %s", rr->state, rr->resrec.name->c, DNSTypeName(rr->resrec.rrtype)); - // This function may be called during sleep when there are no sleep proxy servers - if (rr->resrec.RecordType == kDNSRecordTypeDeregistering) CompleteDeregistration(m, rr); - return mStatus_NoError; - } - - // If a current group registration is pending, we can't send this deregisration till that registration - // has reached the server i.e., the ordering is important. Previously, if we did not send this - // registration in a group, then the previous connection will be torn down as part of sending the - // deregistration. If we send this in a group, we need to locate the resource record that was used - // to send this registration and terminate that connection. This means all the updates on that might - // be lost (assuming the response is not waiting for us at the socket) and the retry will send the - // update again sometime in the near future. - // - // NOTE: SSL handshake failures normally free the TCP connection immediately. Hence, you may not - // find the TCP below there. This case can happen only when tcp is trying to actively retransmit - // the request or SSL negotiation taking time i.e resource record is actively trying to get the - // message to the server. During that time a deregister has to happen. - - if (!mDNSOpaque16IsZero(rr->updateid)) - { - AuthRecord *anchorRR; - mDNSBool found = mDNSfalse; - for (anchorRR = m->ResourceRecords; anchorRR; anchorRR = anchorRR->next) - { - if (AuthRecord_uDNS(rr) && mDNSSameOpaque16(anchorRR->updateid, rr->updateid) && anchorRR->tcp) - { - LogInfo("uDNS_DeregisterRecord: Found Anchor RR %s terminated", ARDisplayString(m, anchorRR)); - if (found) - LogMsg("uDNS_DeregisterRecord: ERROR: Another anchorRR %s found", ARDisplayString(m, anchorRR)); - DisposeTCPConn(anchorRR->tcp); - anchorRR->tcp = mDNSNULL; - found = mDNStrue; - } - } - if (!found) LogInfo("uDNSDeregisterRecord: Cannot find the anchor Resource Record for %s, not an error", ARDisplayString(m, rr)); - } - - // Retry logic for deregistration should be no different from sending registration the first time. - // Currently ThisAPInterval most likely is set to the refresh interval - rr->state = regState_DeregPending; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - info = GetAuthInfoForName_internal(m, rr->resrec.name); - if (IsRecordMergeable(m, rr, m->timenow + MERGE_DELAY_TIME)) - { - // Delay the record deregistration by MERGE_DELAY_TIME so that we can merge them - // into one update. If the domain is being deleted, delay by 2 * MERGE_DELAY_TIME - // so that we can merge all the AutoTunnel records and the service records in - // one update (they get deregistered a little apart) - if (info && info->deltime) rr->LastAPTime += (2 * MERGE_DELAY_TIME); - else rr->LastAPTime += MERGE_DELAY_TIME; - } - // IsRecordMergeable could have returned false for several reasons e.g., DontMerge is set or - // no zone information. Most likely it is the latter, CheckRecordUpdates will fetch the zone - // data when it encounters this record. - - if (m->NextuDNSEvent - (rr->LastAPTime + rr->ThisAPInterval) >= 0) - m->NextuDNSEvent = (rr->LastAPTime + rr->ThisAPInterval); - - return mStatus_NoError; - } - -mDNSexport mStatus uDNS_UpdateRecord(mDNS *m, AuthRecord *rr) - { - LogInfo("uDNS_UpdateRecord: Resource Record %##s, state %d", rr->resrec.name->c, rr->state); - switch(rr->state) - { - case regState_DeregPending: - case regState_Unregistered: - // not actively registered - goto unreg_error; - - case regState_NATMap: - case regState_NoTarget: - // change rdata directly since it hasn't been sent yet - if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->resrec.rdata, rr->resrec.rdlength); - SetNewRData(&rr->resrec, rr->NewRData, rr->newrdlength); - rr->NewRData = mDNSNULL; - return mStatus_NoError; - - case regState_Pending: - case regState_Refresh: - case regState_UpdatePending: - // registration in-flight. queue rdata and return - if (rr->QueuedRData && rr->UpdateCallback) - // if unsent rdata is already queued, free it before we replace it - rr->UpdateCallback(m, rr, rr->QueuedRData, rr->QueuedRDLen); - rr->QueuedRData = rr->NewRData; - rr->QueuedRDLen = rr->newrdlength; - rr->NewRData = mDNSNULL; - return mStatus_NoError; - - case regState_Registered: - rr->OrigRData = rr->resrec.rdata; - rr->OrigRDLen = rr->resrec.rdlength; - rr->InFlightRData = rr->NewRData; - rr->InFlightRDLen = rr->newrdlength; - rr->NewRData = mDNSNULL; - rr->state = regState_UpdatePending; - rr->ThisAPInterval = INIT_RECORD_REG_INTERVAL; - rr->LastAPTime = m->timenow - INIT_RECORD_REG_INTERVAL; - return mStatus_NoError; - - case regState_NATError: - LogMsg("ERROR: uDNS_UpdateRecord called for record %##s with bad state regState_NATError", rr->resrec.name->c); - return mStatus_UnknownErr; // states for service records only - - default: LogMsg("uDNS_UpdateRecord: Unknown state %d for %##s", rr->state, rr->resrec.name->c); - } - - unreg_error: - LogMsg("uDNS_UpdateRecord: Requested update of record %##s type %d, in erroneous state %d", - rr->resrec.name->c, rr->resrec.rrtype, rr->state); - return mStatus_Invalid; - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Periodic Execution Routines -#endif - -// The question to be checked is not passed in as an explicit parameter; -// instead it is implicit that the question to be checked is m->CurrentQuestion. -mDNSexport void uDNS_CheckCurrentQuestion(mDNS *const m) - { - DNSQuestion *q = m->CurrentQuestion; - if (m->timenow - NextQSendTime(q) < 0) return; - - if (q->LongLived) - { - switch (q->state) - { - case LLQ_InitialRequest: startLLQHandshake(m, q); break; - case LLQ_SecondaryRequest: - // For PrivateQueries, we need to start the handshake again as we don't do the Challenge/Response step - if (PrivateQuery(q)) - startLLQHandshake(m, q); - else - sendChallengeResponse(m, q, mDNSNULL); - break; - case LLQ_Established: sendLLQRefresh(m, q); break; - case LLQ_Poll: break; // Do nothing (handled below) - } - } - - // We repeat the check above (rather than just making this the "else" case) because startLLQHandshake can change q->state to LLQ_Poll - if (!(q->LongLived && q->state != LLQ_Poll)) - { - if (q->unansweredQueries >= MAX_UCAST_UNANSWERED_QUERIES) - { - DNSServer *orig = q->qDNSServer; - if (orig) - LogInfo("uDNS_CheckCurrentQuestion: Sent %d unanswered queries for %##s (%s) to %#a:%d (%##s)", - q->unansweredQueries, q->qname.c, DNSTypeName(q->qtype), &orig->addr, mDNSVal16(orig->port), orig->domain.c); - - PenalizeDNSServer(m, q); - q->noServerResponse = 1; - } - // There are two cases here. - // - // 1. We have only one DNS server for this question. It is not responding even after we sent MAX_UCAST_UNANSWERED_QUERIES. - // In that case, we need to keep retrying till we get a response. But we need to backoff as we retry. We set - // noServerResponse in the block above and below we do not touch the question interval. When we come here, we - // already waited for the response. We need to send another query right at this moment. We do that below by - // reinitializing dns servers and reissuing the query. - // - // 2. We have more than one DNS server. If at least one server did not respond, we would have set noServerResponse - // either now (the last server in the list) or before (non-last server in the list). In either case, if we have - // reached the end of DNS server list, we need to try again from the beginning. Ideally we should try just the - // servers that did not respond, but for simplicity we try all the servers. Once we reached the end of list, we - // set triedAllServersOnce so that we don't try all the servers aggressively. See PenalizeDNSServer. - if (!q->qDNSServer && q->noServerResponse) - { - DNSServer *new; - DNSQuestion *qptr; - q->triedAllServersOnce = 1; - // Re-initialize all DNS servers for this question. If we have a DNSServer, DNSServerChangeForQuestion will - // handle all the work including setting the new DNS server. - SetValidDNSServers(m, q); - new = GetServerForQuestion(m, q); - if (new) - { - LogInfo("uDNS_checkCurrentQuestion: Retrying question %p %##s (%s) DNS Server %#a:%d ThisQInterval %d", - q, q->qname.c, DNSTypeName(q->qtype), new ? &new->addr : mDNSNULL, mDNSVal16(new ? new->port : zeroIPPort), q->ThisQInterval); - DNSServerChangeForQuestion(m, q, new); - } - for (qptr = q->next ; qptr; qptr = qptr->next) - if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = q->qDNSServer; } - } - if (q->qDNSServer && q->qDNSServer->teststate != DNSServer_Disabled) - { - mDNSu8 *end = m->omsg.data; - mStatus err = mStatus_NoError; - mDNSBool private = mDNSfalse; - - InitializeDNSMessage(&m->omsg.h, q->TargetQID, uQueryFlags); - - if (q->qDNSServer->teststate != DNSServer_Untested || NoTestQuery(q)) - { - end = putQuestion(&m->omsg, m->omsg.data, m->omsg.data + AbsoluteMaxDNSMessageData, &q->qname, q->qtype, q->qclass); - private = PrivateQuery(q); - } - else if (m->timenow - q->qDNSServer->lasttest >= INIT_UCAST_POLL_INTERVAL) // Make sure at least three seconds has elapsed since last test query - { - LogInfo("Sending DNS test query to %#a:%d", &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port)); - q->ThisQInterval = INIT_UCAST_POLL_INTERVAL / QuestionIntervalStep; - q->qDNSServer->lasttest = m->timenow; - end = putQuestion(&m->omsg, m->omsg.data, m->omsg.data + AbsoluteMaxDNSMessageData, DNSRelayTestQuestion, kDNSType_PTR, kDNSClass_IN); - q->qDNSServer->testid = m->omsg.h.id; - } - - if (end > m->omsg.data && (q->qDNSServer->teststate != DNSServer_Failed || NoTestQuery(q))) - { - //LogMsg("uDNS_CheckCurrentQuestion %p %d %p %##s (%s)", q, NextQSendTime(q) - m->timenow, private, q->qname.c, DNSTypeName(q->qtype)); - if (private) - { - if (q->nta) CancelGetZoneData(m, q->nta); - q->nta = StartGetZoneData(m, &q->qname, q->LongLived ? ZoneServiceLLQ : ZoneServiceQuery, PrivateQueryGotZoneData, q); - if (q->state == LLQ_Poll) q->ThisQInterval = (LLQ_POLL_INTERVAL + mDNSRandom(LLQ_POLL_INTERVAL/10)) / QuestionIntervalStep; - } - else - { - debugf("uDNS_CheckCurrentQuestion sending %p %##s (%s) %#a:%d UnansweredQueries %d", - q, q->qname.c, DNSTypeName(q->qtype), - q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort), q->unansweredQueries); - if (!q->LocalSocket) q->LocalSocket = mDNSPlatformUDPSocket(m, zeroIPPort); - if (!q->LocalSocket) err = mStatus_NoMemoryErr; // If failed to make socket (should be very rare), we'll try again next time - else err = mDNSSendDNSMessage(m, &m->omsg, end, q->qDNSServer->interface, q->LocalSocket, &q->qDNSServer->addr, q->qDNSServer->port, mDNSNULL, mDNSNULL); - } - } - - if (err) debugf("ERROR: uDNS_idle - mDNSSendDNSMessage - %d", err); // surpress syslog messages if we have no network - else - { - q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; // Only increase interval if send succeeded - q->unansweredQueries++; - if (q->ThisQInterval > MAX_UCAST_POLL_INTERVAL) - q->ThisQInterval = MAX_UCAST_POLL_INTERVAL; - if (private && q->state != LLQ_Poll) - { - // We don't want to retransmit too soon. Hence, we always schedule our first - // retransmisson at 3 seconds rather than one second - if (q->ThisQInterval < (3 * mDNSPlatformOneSecond)) - q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; - if (q->ThisQInterval > LLQ_POLL_INTERVAL) - q->ThisQInterval = LLQ_POLL_INTERVAL; - LogInfo("uDNS_CheckCurrentQuestion: private non polling question for %##s (%s) will be retried in %d ms", q->qname.c, DNSTypeName(q->qtype), q->ThisQInterval); - } - if (q->qDNSServer->cellIntf) - { - // We don't want to retransmit too soon. Schedule our first retransmisson at - // MIN_UCAST_RETRANS_TIMEOUT seconds. - if (q->ThisQInterval < MIN_UCAST_RETRANS_TIMEOUT) - q->ThisQInterval = MIN_UCAST_RETRANS_TIMEOUT; - } - debugf("uDNS_CheckCurrentQuestion: Increased ThisQInterval to %d for %##s (%s), cell %d", q->ThisQInterval, q->qname.c, DNSTypeName(q->qtype), q->qDNSServer->cellIntf); - } - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - } - else - { - // If we have no server for this query, or the only server is a disabled one, then we deliver - // a transient failure indication to the client. This is important for things like iPhone - // where we want to return timely feedback to the user when no network is available. - // After calling MakeNegativeCacheRecord() we store the resulting record in the - // cache so that it will be visible to other clients asking the same question. - // (When we have a group of identical questions, only the active representative of the group gets - // passed to uDNS_CheckCurrentQuestion -- we only want one set of query packets hitting the wire -- - // but we want *all* of the questions to get answer callbacks.) - - CacheRecord *rr; - const mDNSu32 slot = HashSlot(&q->qname); - CacheGroup *const cg = CacheGroupForName(m, slot, q->qnamehash, &q->qname); - if (cg) - for (rr = cg->members; rr; rr=rr->next) - if (SameNameRecordAnswersQuestion(&rr->resrec, q)) mDNS_PurgeCacheResourceRecord(m, rr); - - if (!q->qDNSServer) - { - if (!mDNSOpaque64IsZero(&q->validDNSServers)) - LogMsg("uDNS_CheckCurrentQuestion: ERROR!!: valid DNSServer bits not zero 0x%x, 0x%x for question %##s (%s)", - q->validDNSServers.l[1], q->validDNSServers.l[0], q->qname.c, DNSTypeName(q->qtype)); - // If we reached the end of list while picking DNS servers, then we don't want to deactivate the - // question. Try after 60 seconds. We find this by looking for valid DNSServers for this question, - // if we find any, then we must have tried them before we came here. This avoids maintaining - // another state variable to see if we had valid DNS servers for this question. - SetValidDNSServers(m, q); - if (mDNSOpaque64IsZero(&q->validDNSServers)) - { - LogInfo("uDNS_CheckCurrentQuestion: no DNS server for %##s (%s)", q->qname.c, DNSTypeName(q->qtype)); - q->ThisQInterval = 0; - } - else - { - DNSQuestion *qptr; - // Pretend that we sent this question. As this is an ActiveQuestion, the NextScheduledQuery should - // be set properly. Also, we need to properly backoff in cases where we don't set the question to - // MaxQuestionInterval when we answer the question e.g., LongLived, we need to keep backing off - q->ThisQInterval = q->ThisQInterval * QuestionIntervalStep; - q->LastQTime = m->timenow; - SetNextQueryTime(m, q); - // Pick a new DNS server now. Otherwise, when the cache is 80% of its expiry, we will try - // to send a query and come back to the same place here and log the above message. - q->qDNSServer = GetServerForQuestion(m, q); - for (qptr = q->next ; qptr; qptr = qptr->next) - if (qptr->DuplicateOf == q) { qptr->validDNSServers = q->validDNSServers; qptr->qDNSServer = q->qDNSServer; } - LogInfo("uDNS_checkCurrentQuestion: Tried all DNS servers, retry question %p SuppressUnusable %d %##s (%s) with DNS Server %#a:%d after 60 seconds, ThisQInterval %d", - q, q->SuppressUnusable, q->qname.c, DNSTypeName(q->qtype), - q->qDNSServer ? &q->qDNSServer->addr : mDNSNULL, mDNSVal16(q->qDNSServer ? q->qDNSServer->port : zeroIPPort), q->ThisQInterval); - } - } - else - { - q->ThisQInterval = 0; - LogMsg("uDNS_CheckCurrentQuestion DNS server %#a:%d for %##s is disabled", &q->qDNSServer->addr, mDNSVal16(q->qDNSServer->port), q->qname.c); - } - - // For some of the WAB queries that we generate form within the mDNSResponder, most of the home routers - // don't understand and return ServFail/NXDomain. In those cases, we don't want to try too often. We try - // every fifteen minutes in that case - MakeNegativeCacheRecord(m, &m->rec.r, &q->qname, q->qnamehash, q->qtype, q->qclass, (DomainEnumQuery(&q->qname) ? 60 * 15 : 60), mDNSInterface_Any, q->qDNSServer); - q->unansweredQueries = 0; - // We're already using the m->CurrentQuestion pointer, so CacheRecordAdd can't use it to walk the question list. - // To solve this problem we set rr->DelayDelivery to a nonzero value (which happens to be 'now') so that we - // momentarily defer generating answer callbacks until mDNS_Execute time. - CreateNewCacheEntry(m, slot, cg, NonZeroTime(m->timenow)); - ScheduleNextCacheCheckTime(m, slot, NonZeroTime(m->timenow)); - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - // MUST NOT touch m->CurrentQuestion (or q) after this -- client callback could have deleted it - } - } - } - -mDNSexport void CheckNATMappings(mDNS *m) - { - mStatus err = mStatus_NoError; - mDNSBool rfc1918 = mDNSv4AddrIsRFC1918(&m->AdvertisedV4.ip.v4); - mDNSBool HaveRoutable = !rfc1918 && !mDNSIPv4AddressIsZero(m->AdvertisedV4.ip.v4); - m->NextScheduledNATOp = m->timenow + 0x3FFFFFFF; - - if (HaveRoutable) m->ExternalAddress = m->AdvertisedV4.ip.v4; - - if (m->NATTraversals && rfc1918) // Do we need to open NAT-PMP socket to receive multicast announcements from router? - { - if (m->NATMcastRecvskt == mDNSNULL) // If we are behind a NAT and the socket hasn't been opened yet, open it - { - // we need to log a message if we can't get our socket, but only the first time (after success) - static mDNSBool needLog = mDNStrue; - m->NATMcastRecvskt = mDNSPlatformUDPSocket(m, NATPMPAnnouncementPort); - if (!m->NATMcastRecvskt) - { - if (needLog) - { - LogMsg("CheckNATMappings: Failed to allocate port 5350 UDP multicast socket for NAT-PMP announcements"); - needLog = mDNSfalse; - } - } - else - needLog = mDNStrue; - } - } - else // else, we don't want to listen for announcements, so close them if they're open - { - if (m->NATMcastRecvskt) { mDNSPlatformUDPClose(m->NATMcastRecvskt); m->NATMcastRecvskt = mDNSNULL; } - if (m->SSDPSocket) { debugf("CheckNATMappings destroying SSDPSocket %p", &m->SSDPSocket); mDNSPlatformUDPClose(m->SSDPSocket); m->SSDPSocket = mDNSNULL; } - } - - if (!m->NATTraversals) - m->retryGetAddr = m->timenow + 0x78000000; - else - { - if (m->timenow - m->retryGetAddr >= 0) - { - err = uDNS_SendNATMsg(m, mDNSNULL); // Will also do UPnP discovery for us, if necessary - if (!err) - { - if (m->retryIntervalGetAddr < NATMAP_INIT_RETRY) m->retryIntervalGetAddr = NATMAP_INIT_RETRY; - else if (m->retryIntervalGetAddr < NATMAP_MAX_RETRY_INTERVAL / 2) m->retryIntervalGetAddr *= 2; - else m->retryIntervalGetAddr = NATMAP_MAX_RETRY_INTERVAL; - } - LogInfo("CheckNATMappings retryGetAddr sent address request err %d interval %d", err, m->retryIntervalGetAddr); - - // Always update m->retryGetAddr, even if we fail to send the packet. Otherwise in cases where we can't send the packet - // (like when we have no active interfaces) we'll spin in an infinite loop repeatedly failing to send the packet - m->retryGetAddr = m->timenow + m->retryIntervalGetAddr; - } - // Even when we didn't send the GetAddr packet, still need to make sure NextScheduledNATOp is set correctly - if (m->NextScheduledNATOp - m->retryGetAddr > 0) - m->NextScheduledNATOp = m->retryGetAddr; - } - - if (m->CurrentNATTraversal) LogMsg("WARNING m->CurrentNATTraversal already in use"); - m->CurrentNATTraversal = m->NATTraversals; - - while (m->CurrentNATTraversal) - { - NATTraversalInfo *cur = m->CurrentNATTraversal; - m->CurrentNATTraversal = m->CurrentNATTraversal->next; - - if (HaveRoutable) // If not RFC 1918 address, our own address and port are effectively our external address and port - { - cur->ExpiryTime = 0; - cur->NewResult = mStatus_NoError; - } - else if (cur->Protocol) // Check if it's time to send port mapping packets - { - if (m->timenow - cur->retryPortMap >= 0) // Time to do something with this mapping - { - if (cur->ExpiryTime && cur->ExpiryTime - m->timenow < 0) // Mapping has expired - { - cur->ExpiryTime = 0; - cur->retryInterval = NATMAP_INIT_RETRY; - } - - //LogMsg("uDNS_SendNATMsg"); - err = uDNS_SendNATMsg(m, cur); - - if (cur->ExpiryTime) // If have active mapping then set next renewal time halfway to expiry - NATSetNextRenewalTime(m, cur); - else // else no mapping; use exponential backoff sequence - { - if (cur->retryInterval < NATMAP_INIT_RETRY ) cur->retryInterval = NATMAP_INIT_RETRY; - else if (cur->retryInterval < NATMAP_MAX_RETRY_INTERVAL / 2) cur->retryInterval *= 2; - else cur->retryInterval = NATMAP_MAX_RETRY_INTERVAL; - cur->retryPortMap = m->timenow + cur->retryInterval; - } - } - - if (m->NextScheduledNATOp - cur->retryPortMap > 0) - m->NextScheduledNATOp = cur->retryPortMap; - } - - // Notify the client if necessary. We invoke the callback if: - // (1) we have an ExternalAddress, or we've tried and failed a couple of times to discover it - // and (2) the client doesn't want a mapping, or the client won't need a mapping, or the client has a successful mapping, or we've tried and failed a couple of times - // and (3) we have new data to give the client that's changed since the last callback - // Time line is: Send, Wait 500ms, Send, Wait 1sec, Send, Wait 2sec, Send - // At this point we've sent three requests without an answer, we've just sent our fourth request, - // retryIntervalGetAddr is now 4 seconds, which is greater than NATMAP_INIT_RETRY * 8 (2 seconds), - // so we return an error result to the caller. - if (!mDNSIPv4AddressIsZero(m->ExternalAddress) || m->retryIntervalGetAddr > NATMAP_INIT_RETRY * 8) - { - const mStatus EffectiveResult = cur->NewResult ? cur->NewResult : mDNSv4AddrIsRFC1918(&m->ExternalAddress) ? mStatus_DoubleNAT : mStatus_NoError; - const mDNSIPPort ExternalPort = HaveRoutable ? cur->IntPort : - !mDNSIPv4AddressIsZero(m->ExternalAddress) && cur->ExpiryTime ? cur->RequestedPort : zeroIPPort; - if (!cur->Protocol || HaveRoutable || cur->ExpiryTime || cur->retryInterval > NATMAP_INIT_RETRY * 8) - if (!mDNSSameIPv4Address(cur->ExternalAddress, m->ExternalAddress) || - !mDNSSameIPPort (cur->ExternalPort, ExternalPort) || - cur->Result != EffectiveResult) - { - //LogMsg("NAT callback %d %d %d", cur->Protocol, cur->ExpiryTime, cur->retryInterval); - if (cur->Protocol && mDNSIPPortIsZero(ExternalPort) && !mDNSIPv4AddressIsZero(m->Router.ip.v4)) - { - if (!EffectiveResult) - LogInfo("CheckNATMapping: Failed to obtain NAT port mapping %p from router %#a external address %.4a internal port %5d interval %d error %d", - cur, &m->Router, &m->ExternalAddress, mDNSVal16(cur->IntPort), cur->retryInterval, EffectiveResult); - else - LogMsg("CheckNATMapping: Failed to obtain NAT port mapping %p from router %#a external address %.4a internal port %5d interval %d error %d", - cur, &m->Router, &m->ExternalAddress, mDNSVal16(cur->IntPort), cur->retryInterval, EffectiveResult); - } - - cur->ExternalAddress = m->ExternalAddress; - cur->ExternalPort = ExternalPort; - cur->Lifetime = cur->ExpiryTime && !mDNSIPPortIsZero(ExternalPort) ? - (cur->ExpiryTime - m->timenow + mDNSPlatformOneSecond/2) / mDNSPlatformOneSecond : 0; - cur->Result = EffectiveResult; - mDNS_DropLockBeforeCallback(); // Allow client to legally make mDNS API calls from the callback - if (cur->clientCallback) - cur->clientCallback(m, cur); - mDNS_ReclaimLockAfterCallback(); // Decrement mDNS_reentrancy to block mDNS API calls again - // MUST NOT touch cur after invoking the callback - } - } - } - } - -mDNSlocal mDNSs32 CheckRecordUpdates(mDNS *m) - { - AuthRecord *rr; - mDNSs32 nextevent = m->timenow + 0x3FFFFFFF; - - CheckGroupRecordUpdates(m); - - for (rr = m->ResourceRecords; rr; rr = rr->next) - { - if (!AuthRecord_uDNS(rr)) continue; - if (rr->state == regState_NoTarget) {debugf("CheckRecordUpdates: Record %##s in NoTarget", rr->resrec.name->c); continue;} - // While we are waiting for the port mapping, we have nothing to do. The port mapping callback - // will take care of this - if (rr->state == regState_NATMap) {debugf("CheckRecordUpdates: Record %##s in NATMap", rr->resrec.name->c); continue;} - if (rr->state == regState_Pending || rr->state == regState_DeregPending || rr->state == regState_UpdatePending || - rr->state == regState_Refresh || rr->state == regState_Registered) - { - if (rr->LastAPTime + rr->ThisAPInterval - m->timenow <= 0) - { - if (rr->tcp) { DisposeTCPConn(rr->tcp); rr->tcp = mDNSNULL; } - if (!rr->nta || mDNSIPv4AddressIsZero(rr->nta->Addr.ip.v4)) - { - // Zero out the updateid so that if we have a pending response from the server, it won't - // be accepted as a valid response. If we accept the response, we might free the new "nta" - if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); } - rr->nta = StartGetZoneData(m, rr->resrec.name, ZoneServiceUpdate, RecordRegistrationGotZoneData, rr); - - // We have just started the GetZoneData. We need to wait for it to finish. SetRecordRetry here - // schedules the update timer to fire in the future. - // - // There are three cases. - // - // 1) When the updates are sent the first time, the first retry is intended to be at three seconds - // in the future. But by calling SetRecordRetry here we set it to nine seconds. But it does not - // matter because when the answer comes back, RecordRegistrationGotZoneData resets the interval - // back to INIT_RECORD_REG_INTERVAL. This also gives enough time for the query. - // - // 2) In the case of update errors (updateError), this causes further backoff as - // RecordRegistrationGotZoneData does not reset the timer. This is intentional as in the case of - // errors, we don't want to update aggressively. - // - // 3) We might be refreshing the update. This is very similar to case (1). RecordRegistrationGotZoneData - // resets it back to INIT_RECORD_REG_INTERVAL. - // - SetRecordRetry(m, rr, 0); - } - else if (rr->state == regState_DeregPending) SendRecordDeregistration(m, rr); - else SendRecordRegistration(m, rr); - } - } - if (nextevent - (rr->LastAPTime + rr->ThisAPInterval) > 0) - nextevent = (rr->LastAPTime + rr->ThisAPInterval); - } - return nextevent; - } - -mDNSexport void uDNS_Tasks(mDNS *const m) - { - mDNSs32 nexte; - DNSServer *d; - - m->NextuDNSEvent = m->timenow + 0x3FFFFFFF; - - nexte = CheckRecordUpdates(m); - if (m->NextuDNSEvent - nexte > 0) - m->NextuDNSEvent = nexte; - - for (d = m->DNSServers; d; d=d->next) - if (d->penaltyTime) - { - if (m->timenow - d->penaltyTime >= 0) - { - LogInfo("DNS server %#a:%d out of penalty box", &d->addr, mDNSVal16(d->port)); - d->penaltyTime = 0; - } - else - if (m->NextuDNSEvent - d->penaltyTime > 0) - m->NextuDNSEvent = d->penaltyTime; - } - - if (m->CurrentQuestion) - LogMsg("uDNS_Tasks ERROR m->CurrentQuestion already set: %##s (%s)", m->CurrentQuestion->qname.c, DNSTypeName(m->CurrentQuestion->qtype)); - m->CurrentQuestion = m->Questions; - while (m->CurrentQuestion && m->CurrentQuestion != m->NewQuestions) - { - DNSQuestion *const q = m->CurrentQuestion; - if (ActiveQuestion(q) && !mDNSOpaque16IsZero(q->TargetQID)) - { - uDNS_CheckCurrentQuestion(m); - if (q == m->CurrentQuestion) - if (m->NextuDNSEvent - NextQSendTime(q) > 0) - m->NextuDNSEvent = NextQSendTime(q); - } - // If m->CurrentQuestion wasn't modified out from under us, advance it now - // We can't do this at the start of the loop because uDNS_CheckCurrentQuestion() - // depends on having m->CurrentQuestion point to the right question - if (m->CurrentQuestion == q) - m->CurrentQuestion = q->next; - } - m->CurrentQuestion = mDNSNULL; - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Startup, Shutdown, and Sleep -#endif - -mDNSexport void SleepRecordRegistrations(mDNS *m) - { - AuthRecord *rr; - for (rr = m->ResourceRecords; rr; rr=rr->next) - { - if (AuthRecord_uDNS(rr)) - { - // Zero out the updateid so that if we have a pending response from the server, it won't - // be accepted as a valid response. - if (rr->nta) { rr->updateid = zeroID; CancelGetZoneData(m, rr->nta); rr->nta = mDNSNULL; } - - if (rr->NATinfo.clientContext) - { - mDNS_StopNATOperation_internal(m, &rr->NATinfo); - rr->NATinfo.clientContext = mDNSNULL; - } - // We are waiting to update the resource record. The original data of the record is - // in OrigRData and the updated value is in InFlightRData. Free the old and the new - // one will be registered when we come back. - if (rr->state == regState_UpdatePending) - { - // act as if the update succeeded, since we're about to delete the name anyway - rr->state = regState_Registered; - // deallocate old RData - if (rr->UpdateCallback) rr->UpdateCallback(m, rr, rr->OrigRData, rr->OrigRDLen); - SetNewRData(&rr->resrec, rr->InFlightRData, rr->InFlightRDLen); - rr->OrigRData = mDNSNULL; - rr->InFlightRData = mDNSNULL; - } - - // If we have not begun the registration process i.e., never sent a registration packet, - // then uDNS_DeregisterRecord will not send a deregistration - uDNS_DeregisterRecord(m, rr); - - // When we wake, we call ActivateUnicastRegistration which starts at StartGetZoneData - } - } - } - -mDNSexport void mDNS_AddSearchDomain(const domainname *const domain, mDNSInterfaceID InterfaceID) - { - SearchListElem **p; - SearchListElem *tmp = mDNSNULL; - - // Check to see if we already have this domain in our list - for (p = &SearchList; *p; p = &(*p)->next) - if (((*p)->InterfaceID == InterfaceID) && SameDomainName(&(*p)->domain, domain)) - { - // If domain is already in list, and marked for deletion, unmark the delete - // Be careful not to touch the other flags that may be present - LogInfo("mDNS_AddSearchDomain already in list %##s", domain->c); - if ((*p)->flag & SLE_DELETE) (*p)->flag &= ~SLE_DELETE; - tmp = *p; - *p = tmp->next; - tmp->next = mDNSNULL; - break; - } - - - // move to end of list so that we maintain the same order - while (*p) p = &(*p)->next; - - if (tmp) *p = tmp; - else - { - // if domain not in list, add to list, mark as add (1) - *p = mDNSPlatformMemAllocate(sizeof(SearchListElem)); - if (!*p) { LogMsg("ERROR: mDNS_AddSearchDomain - malloc"); return; } - mDNSPlatformMemZero(*p, sizeof(SearchListElem)); - AssignDomainName(&(*p)->domain, domain); - (*p)->next = mDNSNULL; - (*p)->InterfaceID = InterfaceID; - LogInfo("mDNS_AddSearchDomain created new %##s, InterfaceID %p", domain->c, InterfaceID); - } - } - -mDNSlocal void FreeARElemCallback(mDNS *const m, AuthRecord *const rr, mStatus result) - { - (void)m; // unused - if (result == mStatus_MemFree) mDNSPlatformMemFree(rr->RecordContext); - } - -mDNSlocal void FoundDomain(mDNS *const m, DNSQuestion *question, const ResourceRecord *const answer, QC_result AddRecord) - { - SearchListElem *slElem = question->QuestionContext; - mStatus err; - const char *name; - - if (answer->rrtype != kDNSType_PTR) return; - if (answer->RecordType == kDNSRecordTypePacketNegative) return; - if (answer->InterfaceID == mDNSInterface_LocalOnly) return; - - if (question == &slElem->BrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowse]; - else if (question == &slElem->DefBrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseDefault]; - else if (question == &slElem->AutomaticBrowseQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeBrowseAutomatic]; - else if (question == &slElem->RegisterQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeRegistration]; - else if (question == &slElem->DefRegisterQ) name = mDNS_DomainTypeNames[mDNS_DomainTypeRegistrationDefault]; - else { LogMsg("FoundDomain - unknown question"); return; } - - LogInfo("FoundDomain: %p %s %s Q %##s A %s", answer->InterfaceID, AddRecord ? "Add" : "Rmv", name, question->qname.c, RRDisplayString(m, answer)); - - if (AddRecord) - { - ARListElem *arElem = mDNSPlatformMemAllocate(sizeof(ARListElem)); - if (!arElem) { LogMsg("ERROR: FoundDomain out of memory"); return; } - mDNS_SetupResourceRecord(&arElem->ar, mDNSNULL, mDNSInterface_LocalOnly, kDNSType_PTR, 7200, kDNSRecordTypeShared, AuthRecordLocalOnly, FreeARElemCallback, arElem); - MakeDomainNameFromDNSNameString(&arElem->ar.namestorage, name); - AppendDNSNameString (&arElem->ar.namestorage, "local"); - AssignDomainName(&arElem->ar.resrec.rdata->u.name, &answer->rdata->u.name); - LogInfo("FoundDomain: Registering %s", ARDisplayString(m, &arElem->ar)); - err = mDNS_Register(m, &arElem->ar); - if (err) { LogMsg("ERROR: FoundDomain - mDNS_Register returned %d", err); mDNSPlatformMemFree(arElem); return; } - arElem->next = slElem->AuthRecs; - slElem->AuthRecs = arElem; - } - else - { - ARListElem **ptr = &slElem->AuthRecs; - while (*ptr) - { - if (SameDomainName(&(*ptr)->ar.resrec.rdata->u.name, &answer->rdata->u.name)) - { - ARListElem *dereg = *ptr; - *ptr = (*ptr)->next; - LogInfo("FoundDomain: Deregistering %s", ARDisplayString(m, &dereg->ar)); - err = mDNS_Deregister(m, &dereg->ar); - if (err) LogMsg("ERROR: FoundDomain - mDNS_Deregister returned %d", err); - // Memory will be freed in the FreeARElemCallback - } - else - ptr = &(*ptr)->next; - } - } - } - -#if APPLE_OSX_mDNSResponder && MACOSX_MDNS_MALLOC_DEBUGGING -mDNSexport void udns_validatelists(void *const v) - { - mDNS *const m = v; - - NATTraversalInfo *n; - for (n = m->NATTraversals; n; n=n->next) - if (n->next == (NATTraversalInfo *)~0 || n->clientCallback == (NATTraversalClientCallback)~0) - LogMemCorruption("m->NATTraversals: %p is garbage", n); - - DNSServer *d; - for (d = m->DNSServers; d; d=d->next) - if (d->next == (DNSServer *)~0 || d->teststate > DNSServer_Disabled) - LogMemCorruption("m->DNSServers: %p is garbage (%d)", d, d->teststate); - - DomainAuthInfo *info; - for (info = m->AuthInfoList; info; info = info->next) - if (info->next == (DomainAuthInfo *)~0 || info->AutoTunnel == (const char*)~0) - LogMemCorruption("m->AuthInfoList: %p is garbage (%X)", info, info->AutoTunnel); - - HostnameInfo *hi; - for (hi = m->Hostnames; hi; hi = hi->next) - if (hi->next == (HostnameInfo *)~0 || hi->StatusCallback == (mDNSRecordCallback*)~0) - LogMemCorruption("m->Hostnames: %p is garbage", n); - - SearchListElem *ptr; - for (ptr = SearchList; ptr; ptr = ptr->next) - if (ptr->next == (SearchListElem *)~0 || ptr->AuthRecs == (void*)~0) - LogMemCorruption("SearchList: %p is garbage (%X)", ptr, ptr->AuthRecs); - } -#endif - -// This should probably move to the UDS daemon -- the concept of legacy clients and automatic registration / automatic browsing -// is really a UDS API issue, not something intrinsic to uDNS - -mDNSexport mStatus uDNS_SetupSearchDomains(mDNS *const m, int action) - { - SearchListElem **p = &SearchList, *ptr; - mStatus err; - - // step 1: mark each element for removal - for (ptr = SearchList; ptr; ptr = ptr->next) ptr->flag |= SLE_DELETE; - - // Make sure we have the search domains from the platform layer so that if we start the WAB - // queries below, we have the latest information - mDNS_Lock(m); - mDNSPlatformSetDNSConfig(m, mDNSfalse, mDNStrue, mDNSNULL, mDNSNULL, mDNSNULL); - mDNS_Unlock(m); - - if (action & UDNS_START_WAB_QUERY) - m->StartWABQueries = mDNStrue; - - // delete elems marked for removal, do queries for elems marked add - while (*p) - { - ptr = *p; - LogInfo("uDNS_SetupSearchDomains:action %d: Flags %d, AuthRecs %p, InterfaceID %p %##s", action, ptr->flag, ptr->AuthRecs, ptr->InterfaceID, ptr->domain.c); - if (ptr->flag & SLE_DELETE) - { - ARListElem *arList = ptr->AuthRecs; - ptr->AuthRecs = mDNSNULL; - *p = ptr->next; - - // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries - // We suppressed the domain enumeration for scoped search domains below. When we enable that - // enable this. - if ((ptr->flag & SLE_WAB_QUERY_STARTED) && - !SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) - { - mDNS_StopGetDomains(m, &ptr->BrowseQ); - mDNS_StopGetDomains(m, &ptr->RegisterQ); - mDNS_StopGetDomains(m, &ptr->DefBrowseQ); - mDNS_StopGetDomains(m, &ptr->DefRegisterQ); - mDNS_StopGetDomains(m, &ptr->AutomaticBrowseQ); - } - - mDNSPlatformMemFree(ptr); - - // deregister records generated from answers to the query - while (arList) - { - ARListElem *dereg = arList; - arList = arList->next; - debugf("Deregistering PTR %##s -> %##s", dereg->ar.resrec.name->c, dereg->ar.resrec.rdata->u.name.c); - err = mDNS_Deregister(m, &dereg->ar); - if (err) LogMsg("uDNS_SetupSearchDomains:: ERROR!! mDNS_Deregister returned %d", err); - // Memory will be freed in the FreeARElemCallback - } - continue; - } - - if ((action & UDNS_START_WAB_QUERY) && !(ptr->flag & SLE_WAB_QUERY_STARTED)) - { - // If the user has "local" in their DNS searchlist, we ignore that for the purposes of domain enumeration queries. - // Also, suppress the domain enumeration for scoped search domains for now until there is a need. - if (!SameDomainName(&ptr->domain, &localdomain) && (ptr->InterfaceID == mDNSInterface_Any)) - { - mStatus err1, err2, err3, err4, err5; - err1 = mDNS_GetDomains(m, &ptr->BrowseQ, mDNS_DomainTypeBrowse, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); - err2 = mDNS_GetDomains(m, &ptr->DefBrowseQ, mDNS_DomainTypeBrowseDefault, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); - err3 = mDNS_GetDomains(m, &ptr->RegisterQ, mDNS_DomainTypeRegistration, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); - err4 = mDNS_GetDomains(m, &ptr->DefRegisterQ, mDNS_DomainTypeRegistrationDefault, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); - err5 = mDNS_GetDomains(m, &ptr->AutomaticBrowseQ, mDNS_DomainTypeBrowseAutomatic, &ptr->domain, ptr->InterfaceID, FoundDomain, ptr); - if (err1 || err2 || err3 || err4 || err5) - LogMsg("uDNS_SetupSearchDomains: GetDomains for domain %##s returned error(s):\n" - "%d (mDNS_DomainTypeBrowse)\n" - "%d (mDNS_DomainTypeBrowseDefault)\n" - "%d (mDNS_DomainTypeRegistration)\n" - "%d (mDNS_DomainTypeRegistrationDefault)" - "%d (mDNS_DomainTypeBrowseAutomatic)\n", - ptr->domain.c, err1, err2, err3, err4, err5); - ptr->flag |= SLE_WAB_QUERY_STARTED; - } - } - - p = &ptr->next; - } - return mStatus_NoError; - } - -mDNSexport domainname *uDNS_GetNextSearchDomain(mDNS *const m, mDNSInterfaceID InterfaceID, mDNSs8 *searchIndex, mDNSBool ignoreDotLocal) - { - SearchListElem *p = SearchList; - int count = *searchIndex; - (void) m; // unused - - if (count < 0) { LogMsg("uDNS_GetNextSearchDomain: count %d less than zero", count); return mDNSNULL; } - - // skip the domains that we already looked at before - for (; count; count--) p = p->next; - - while (p) - { - int labels = CountLabels(&p->domain); - if (labels > 0) - { - const domainname *d = SkipLeadingLabels(&p->domain, labels - 1); - if (SameDomainLabel(d->c, (const mDNSu8 *)"\x4""arpa")) - { - LogInfo("uDNS_GetNextSearchDomain: skipping search domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); - (*searchIndex)++; - p = p->next; - continue; - } - if (ignoreDotLocal && SameDomainLabel(d->c, (const mDNSu8 *)"\x5""local")) - { - LogInfo("uDNS_GetNextSearchDomain: skipping local domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); - (*searchIndex)++; - p = p->next; - continue; - } - } - // Point to the next one in the list which we will look at next time. - (*searchIndex)++; - // When we are appending search domains in a ActiveDirectory domain, the question's InterfaceID - // set to mDNSInterface_Unicast. Match the unscoped entries in that case. - if (((InterfaceID == mDNSInterface_Unicast) && (p->InterfaceID == mDNSInterface_Any)) || - p->InterfaceID == InterfaceID) - { - LogInfo("uDNS_GetNextSearchDomain returning domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); - return &p->domain; - } - LogInfo("uDNS_GetNextSearchDomain skipping domain %##s, InterfaceID %p", p->domain.c, p->InterfaceID); - p = p->next; - } - return mDNSNULL; - } - -mDNSlocal void FlushAddressCacheRecords(mDNS *const m) - { - mDNSu32 slot; - CacheGroup *cg; - CacheRecord *cr; - FORALL_CACHERECORDS(slot, cg, cr) - { - if (cr->resrec.InterfaceID) continue; - - // If a resource record can answer A or AAAA, they need to be flushed so that we will - // never used to deliver an ADD or RMV - if (RRTypeAnswersQuestionType(&cr->resrec, kDNSType_A) || - RRTypeAnswersQuestionType(&cr->resrec, kDNSType_AAAA)) - { - LogInfo("FlushAddressCacheRecords: Purging Resourcerecord %s", CRDisplayString(m, cr)); - mDNS_PurgeCacheResourceRecord(m, cr); - } - } - } - -// Retry questions which has seach domains appended -mDNSexport void RetrySearchDomainQuestions(mDNS *const m) - { - // Purge all the A/AAAA cache records and restart the queries. mDNSCoreRestartAddressQueries - // does this. When we restart the question, we first want to try the new search domains rather - // than use the entries that is already in the cache. When we appended search domains, we might - // have created cache entries which is no longer valid as there are new search domains now - - LogInfo("RetrySearchDomainQuestions: Calling mDNSCoreRestartAddressQueries"); - mDNSCoreRestartAddressQueries(m, mDNStrue, FlushAddressCacheRecords, mDNSNULL, mDNSNULL); - } - -// Construction of Default Browse domain list (i.e. when clients pass NULL) is as follows: -// 1) query for b._dns-sd._udp.local on LocalOnly interface -// (.local manually generated via explicit callback) -// 2) for each search domain (from prefs pane), query for b._dns-sd._udp.<searchdomain>. -// 3) for each result from (2), register LocalOnly PTR record b._dns-sd._udp.local. -> <result> -// 4) result above should generate a callback from question in (1). result added to global list -// 5) global list delivered to client via GetSearchDomainList() -// 6) client calls to enumerate domains now go over LocalOnly interface -// (!!!KRS may add outgoing interface in addition) - -struct CompileTimeAssertionChecks_uDNS - { - // Check our structures are reasonable sizes. Including overly-large buffers, or embedding - // other overly-large structures instead of having a pointer to them, can inadvertently - // cause structure sizes (and therefore memory usage) to balloon unreasonably. - char sizecheck_tcpInfo_t [(sizeof(tcpInfo_t) <= 9056) ? 1 : -1]; - char sizecheck_SearchListElem[(sizeof(SearchListElem) <= 5000) ? 1 : -1]; - }; |