diff options
Diffstat (limited to 'src/tools/mdnssd/DNSCommon.c')
| -rw-r--r-- | src/tools/mdnssd/DNSCommon.c | 3153 |
1 files changed, 0 insertions, 3153 deletions
diff --git a/src/tools/mdnssd/DNSCommon.c b/src/tools/mdnssd/DNSCommon.c deleted file mode 100644 index e5260683393..00000000000 --- a/src/tools/mdnssd/DNSCommon.c +++ /dev/null @@ -1,3153 +0,0 @@ -/* -*- Mode: C; tab-width: 4 -*- - * - * Copyright (c) 2002-2003 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. - */ - -// Set mDNS_InstantiateInlines to tell mDNSEmbeddedAPI.h to instantiate inline functions, if necessary -#define mDNS_InstantiateInlines 1 -#include "DNSCommon.h" - -// Disable certain benign warnings with Microsoft compilers -#if (defined(_MSC_VER)) - // Disable "conditional expression is constant" warning for debug macros. - // Otherwise, this generates warnings for the perfectly natural construct "while(1)" - // If someone knows a variant way of writing "while(1)" that doesn't generate warning messages, please let us know - #pragma warning(disable:4127) - // Disable "array is too small to include a terminating null character" warning - // -- domain labels have an initial length byte, not a terminating null character - #pragma warning(disable:4295) -#endif - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - Program Constants -#endif - -mDNSexport const mDNSInterfaceID mDNSInterface_Any = 0; -mDNSexport const mDNSInterfaceID mDNSInterfaceMark = (mDNSInterfaceID)-1; -mDNSexport const mDNSInterfaceID mDNSInterface_LocalOnly = (mDNSInterfaceID)-2; -mDNSexport const mDNSInterfaceID mDNSInterface_Unicast = (mDNSInterfaceID)-3; -mDNSexport const mDNSInterfaceID mDNSInterface_P2P = (mDNSInterfaceID)-4; - -// Note: Microsoft's proposed "Link Local Multicast Name Resolution Protocol" (LLMNR) is essentially a limited version of -// Multicast DNS, using the same packet formats, naming syntax, and record types as Multicast DNS, but on a different UDP -// port and multicast address, which means it won't interoperate with the existing installed base of Multicast DNS responders. -// LLMNR uses IPv4 multicast address 224.0.0.252, IPv6 multicast address FF02::0001:0003, and UDP port 5355. -// Uncomment the appropriate lines below to build a special Multicast DNS responder for testing interoperability -// with Microsoft's LLMNR client code. - -#define DiscardPortAsNumber 9 -#define SSHPortAsNumber 22 -#define UnicastDNSPortAsNumber 53 -#define SSDPPortAsNumber 1900 -#define IPSECPortAsNumber 4500 -#define NSIPCPortAsNumber 5030 // Port used for dnsextd to talk to local nameserver bound to loopback -#define NATPMPAnnouncementPortAsNumber 5350 -#define NATPMPPortAsNumber 5351 -#define DNSEXTPortAsNumber 5352 // Port used for end-to-end DNS operations like LLQ, Updates with Leases, etc. -#define MulticastDNSPortAsNumber 5353 -#define LoopbackIPCPortAsNumber 5354 -//#define MulticastDNSPortAsNumber 5355 // LLMNR -#define PrivateDNSPortAsNumber 5533 - -mDNSexport const mDNSIPPort DiscardPort = { { DiscardPortAsNumber >> 8, DiscardPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort SSHPort = { { SSHPortAsNumber >> 8, SSHPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort UnicastDNSPort = { { UnicastDNSPortAsNumber >> 8, UnicastDNSPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort SSDPPort = { { SSDPPortAsNumber >> 8, SSDPPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort IPSECPort = { { IPSECPortAsNumber >> 8, IPSECPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort NSIPCPort = { { NSIPCPortAsNumber >> 8, NSIPCPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort NATPMPAnnouncementPort = { { NATPMPAnnouncementPortAsNumber >> 8, NATPMPAnnouncementPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort NATPMPPort = { { NATPMPPortAsNumber >> 8, NATPMPPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort DNSEXTPort = { { DNSEXTPortAsNumber >> 8, DNSEXTPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort MulticastDNSPort = { { MulticastDNSPortAsNumber >> 8, MulticastDNSPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort LoopbackIPCPort = { { LoopbackIPCPortAsNumber >> 8, LoopbackIPCPortAsNumber & 0xFF } }; -mDNSexport const mDNSIPPort PrivateDNSPort = { { PrivateDNSPortAsNumber >> 8, PrivateDNSPortAsNumber & 0xFF } }; - -mDNSexport const OwnerOptData zeroOwner = { 0, 0, { { 0 } }, { { 0 } }, { { 0 } } }; - -mDNSexport const mDNSIPPort zeroIPPort = { { 0 } }; -mDNSexport const mDNSv4Addr zerov4Addr = { { 0 } }; -mDNSexport const mDNSv6Addr zerov6Addr = { { 0 } }; -mDNSexport const mDNSEthAddr zeroEthAddr = { { 0 } }; -mDNSexport const mDNSv4Addr onesIPv4Addr = { { 255, 255, 255, 255 } }; -mDNSexport const mDNSv6Addr onesIPv6Addr = { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 } }; -mDNSexport const mDNSEthAddr onesEthAddr = { { 255, 255, 255, 255, 255, 255 } }; -mDNSexport const mDNSAddr zeroAddr = { mDNSAddrType_None, {{{ 0 }}} }; - -mDNSexport const mDNSv4Addr AllDNSAdminGroup = { { 239, 255, 255, 251 } }; -mDNSexport const mDNSv4Addr AllHosts_v4 = { { 224, 0, 0, 1 } }; // For NAT-PMP Annoucements -mDNSexport const mDNSv6Addr AllHosts_v6 = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01 } }; -mDNSexport const mDNSv6Addr NDP_prefix = { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01, 0xFF,0x00,0x00,0xFB } }; // FF02:0:0:0:0:1:FF00::/104 -mDNSexport const mDNSEthAddr AllHosts_v6_Eth = { { 0x33, 0x33, 0x00, 0x00, 0x00, 0x01 } }; -mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 251 } } } }; -//mDNSexport const mDNSAddr AllDNSLinkGroup_v4 = { mDNSAddrType_IPv4, { { { 224, 0, 0, 252 } } } }; // LLMNR -mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0xFB } } } }; -//mDNSexport const mDNSAddr AllDNSLinkGroup_v6 = { mDNSAddrType_IPv6, { { { 0xFF,0x02,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00, 0x00,0x01,0x00,0x03 } } } }; // LLMNR - -mDNSexport const mDNSOpaque16 zeroID = { { 0, 0 } }; -mDNSexport const mDNSOpaque16 onesID = { { 255, 255 } }; -mDNSexport const mDNSOpaque16 QueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery, 0 } }; -mDNSexport const mDNSOpaque16 uQueryFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_StdQuery | kDNSFlag0_RD, 0 } }; -mDNSexport const mDNSOpaque16 ResponseFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_StdQuery | kDNSFlag0_AA, 0 } }; -mDNSexport const mDNSOpaque16 UpdateReqFlags = { { kDNSFlag0_QR_Query | kDNSFlag0_OP_Update, 0 } }; -mDNSexport const mDNSOpaque16 UpdateRespFlags = { { kDNSFlag0_QR_Response | kDNSFlag0_OP_Update, 0 } }; - -mDNSexport const mDNSOpaque64 zeroOpaque64 = { { 0 } }; - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - General Utility Functions -#endif - -// return true for RFC1918 private addresses -mDNSexport mDNSBool mDNSv4AddrIsRFC1918(mDNSv4Addr *addr) - { - return ((addr->b[0] == 10) || // 10/8 prefix - (addr->b[0] == 172 && (addr->b[1] & 0xF0) == 16) || // 172.16/12 - (addr->b[0] == 192 && addr->b[1] == 168)); // 192.168/16 - } - -mDNSexport NetworkInterfaceInfo *GetFirstActiveInterface(NetworkInterfaceInfo *intf) - { - while (intf && !intf->InterfaceActive) intf = intf->next; - return(intf); - } - -mDNSexport mDNSInterfaceID GetNextActiveInterfaceID(const NetworkInterfaceInfo *intf) - { - const NetworkInterfaceInfo *next = GetFirstActiveInterface(intf->next); - if (next) return(next->InterfaceID); else return(mDNSNULL); - } - -mDNSexport mDNSu32 NumCacheRecordsForInterfaceID(const mDNS *const m, mDNSInterfaceID id) - { - mDNSu32 slot, used = 0; - CacheGroup *cg; - const CacheRecord *rr; - FORALL_CACHERECORDS(slot, cg, rr) - if (rr->resrec.InterfaceID == id) used++; - return(used); - } - -mDNSexport char *DNSTypeName(mDNSu16 rrtype) - { - switch (rrtype) - { - case kDNSType_A: return("Addr"); - case kDNSType_NS: return("NS"); - case kDNSType_CNAME:return("CNAME"); - case kDNSType_SOA: return("SOA"); - case kDNSType_NULL: return("NULL"); - case kDNSType_PTR: return("PTR"); - case kDNSType_HINFO:return("HINFO"); - case kDNSType_TXT: return("TXT"); - case kDNSType_AAAA: return("AAAA"); - case kDNSType_SRV: return("SRV"); - case kDNSType_OPT: return("OPT"); - case kDNSType_NSEC: return("NSEC"); - case kDNSType_TSIG: return("TSIG"); - case kDNSQType_ANY: return("ANY"); - default: { - static char buffer[16]; - mDNS_snprintf(buffer, sizeof(buffer), "(%d)", rrtype); - return(buffer); - } - } - } - -// Note slight bug: this code uses the rdlength from the ResourceRecord object, to display -// the rdata from the RDataBody object. Sometimes this could be the wrong length -- but as -// long as this routine is only used for debugging messages, it probably isn't a big problem. -mDNSexport char *GetRRDisplayString_rdb(const ResourceRecord *const rr, const RDataBody *const rd1, char *const buffer) - { - const RDataBody2 *const rd = (RDataBody2 *)rd1; - #define RemSpc (MaxMsg-1-length) - char *ptr = buffer; - mDNSu32 length = mDNS_snprintf(buffer, MaxMsg-1, "%4d %##s %s ", rr->rdlength, rr->name->c, DNSTypeName(rr->rrtype)); - if (rr->RecordType == kDNSRecordTypePacketNegative) return(buffer); - if (!rr->rdlength) { mDNS_snprintf(buffer+length, RemSpc, "<< ZERO RDATA LENGTH >>"); return(buffer); } - - switch (rr->rrtype) - { - case kDNSType_A: mDNS_snprintf(buffer+length, RemSpc, "%.4a", &rd->ipv4); break; - - case kDNSType_NS: // Same as PTR - case kDNSType_CNAME:// Same as PTR - case kDNSType_PTR: mDNS_snprintf(buffer+length, RemSpc, "%##s", rd->name.c); break; - - case kDNSType_SOA: mDNS_snprintf(buffer+length, RemSpc, "%##s %##s %d %d %d %d %d", - rd->soa.mname.c, rd->soa.rname.c, - rd->soa.serial, rd->soa.refresh, rd->soa.retry, rd->soa.expire, rd->soa.min); - break; - - case kDNSType_HINFO:// Display this the same as TXT (show all constituent strings) - case kDNSType_TXT: { - const mDNSu8 *t = rd->txt.c; - while (t < rd->txt.c + rr->rdlength) - { - length += mDNS_snprintf(buffer+length, RemSpc, "%s%#s", t > rd->txt.c ? "|" : "", t); - t += 1 + t[0]; - } - } break; - - case kDNSType_AAAA: mDNS_snprintf(buffer+length, RemSpc, "%.16a", &rd->ipv6); break; - case kDNSType_SRV: mDNS_snprintf(buffer+length, RemSpc, "%u %u %u %##s", - rd->srv.priority, rd->srv.weight, mDNSVal16(rd->srv.port), rd->srv.target.c); break; - - case kDNSType_OPT: { - const rdataOPT *opt; - const rdataOPT *const end = (const rdataOPT *)&rd->data[rr->rdlength]; - length += mDNS_snprintf(buffer+length, RemSpc, "Max %d", rr->rrclass); - for (opt = &rd->opt[0]; opt < end; opt++) - { - switch(opt->opt) - { - case kDNSOpt_LLQ: - length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d", opt->u.llq.vers); - length += mDNS_snprintf(buffer+length, RemSpc, " Op %d", opt->u.llq.llqOp); - length += mDNS_snprintf(buffer+length, RemSpc, " Err/Port %d", opt->u.llq.err); - length += mDNS_snprintf(buffer+length, RemSpc, " ID %08X%08X", opt->u.llq.id.l[0], opt->u.llq.id.l[1]); - length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d", opt->u.llq.llqlease); - break; - case kDNSOpt_Lease: - length += mDNS_snprintf(buffer+length, RemSpc, " Lease %d", opt->u.updatelease); - break; - case kDNSOpt_Owner: - length += mDNS_snprintf(buffer+length, RemSpc, " Vers %d", opt->u.owner.vers); - length += mDNS_snprintf(buffer+length, RemSpc, " Seq %3d", (mDNSu8)opt->u.owner.seq); // Display as unsigned - length += mDNS_snprintf(buffer+length, RemSpc, " MAC %.6a", opt->u.owner.HMAC.b); - if (opt->optlen >= DNSOpt_OwnerData_ID_Wake_Space-4) - { - length += mDNS_snprintf(buffer+length, RemSpc, " I-MAC %.6a", opt->u.owner.IMAC.b); - if (opt->optlen > DNSOpt_OwnerData_ID_Wake_Space-4) - length += mDNS_snprintf(buffer+length, RemSpc, " Password %.6a", opt->u.owner.password.b); - } - break; - default: - length += mDNS_snprintf(buffer+length, RemSpc, " Unknown %d", opt->opt); - break; - } - } - } - break; - - case kDNSType_NSEC: { - mDNSu16 i; - for (i=0; i<255; i++) - if (rd->nsec.bitmap[i>>3] & (128 >> (i&7))) - length += mDNS_snprintf(buffer+length, RemSpc, "%s ", DNSTypeName(i)); - } - break; - - default: mDNS_snprintf(buffer+length, RemSpc, "RDLen %d: %s", rr->rdlength, rd->data); - // Really should scan buffer to check if text is valid UTF-8 and only replace with dots if not - for (ptr = buffer; *ptr; ptr++) if (*ptr < ' ') *ptr = '.'; - break; - } - return(buffer); - } - -// See comments in mDNSEmbeddedAPI.h -#if _PLATFORM_HAS_STRONG_PRNG_ -#define mDNSRandomNumber mDNSPlatformRandomNumber -#else -mDNSlocal mDNSu32 mDNSRandomFromSeed(mDNSu32 seed) - { - return seed * 21 + 1; - } - -mDNSlocal mDNSu32 mDNSMixRandomSeed(mDNSu32 seed, mDNSu8 iteration) - { - return iteration ? mDNSMixRandomSeed(mDNSRandomFromSeed(seed), --iteration) : seed; - } - -mDNSlocal mDNSu32 mDNSRandomNumber() - { - static mDNSBool seeded = mDNSfalse; - static mDNSu32 seed = 0; - if (!seeded) - { - seed = mDNSMixRandomSeed(mDNSPlatformRandomSeed(), 100); - seeded = mDNStrue; - } - return (seed = mDNSRandomFromSeed(seed)); - } -#endif // ! _PLATFORM_HAS_STRONG_PRNG_ - -mDNSexport mDNSu32 mDNSRandom(mDNSu32 max) // Returns pseudo-random result from zero to max inclusive - { - mDNSu32 ret = 0; - mDNSu32 mask = 1; - - while (mask < max) mask = (mask << 1) | 1; - - do ret = mDNSRandomNumber() & mask; - while (ret > max); - - return ret; - } - -mDNSexport mDNSBool mDNSSameAddress(const mDNSAddr *ip1, const mDNSAddr *ip2) - { - if (ip1->type == ip2->type) - { - switch (ip1->type) - { - case mDNSAddrType_None : return(mDNStrue); // Empty addresses have no data and are therefore always equal - case mDNSAddrType_IPv4 : return(mDNSBool)(mDNSSameIPv4Address(ip1->ip.v4, ip2->ip.v4)); - case mDNSAddrType_IPv6 : return(mDNSBool)(mDNSSameIPv6Address(ip1->ip.v6, ip2->ip.v6)); - } - } - return(mDNSfalse); - } - -mDNSexport mDNSBool mDNSAddrIsDNSMulticast(const mDNSAddr *ip) - { - switch(ip->type) - { - case mDNSAddrType_IPv4: return(mDNSBool)(mDNSSameIPv4Address(ip->ip.v4, AllDNSLinkGroup_v4.ip.v4)); - case mDNSAddrType_IPv6: return(mDNSBool)(mDNSSameIPv6Address(ip->ip.v6, AllDNSLinkGroup_v6.ip.v6)); - default: return(mDNSfalse); - } - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - Domain Name Utility Functions -#endif - -mDNSexport mDNSBool SameDomainLabel(const mDNSu8 *a, const mDNSu8 *b) - { - int i; - const int len = *a++; - - if (len > MAX_DOMAIN_LABEL) - { debugf("Malformed label (too long)"); return(mDNSfalse); } - - if (len != *b++) return(mDNSfalse); - for (i=0; i<len; i++) - { - mDNSu8 ac = *a++; - mDNSu8 bc = *b++; - if (mDNSIsUpperCase(ac)) ac += 'a' - 'A'; - if (mDNSIsUpperCase(bc)) bc += 'a' - 'A'; - if (ac != bc) return(mDNSfalse); - } - return(mDNStrue); - } - -mDNSexport mDNSBool SameDomainName(const domainname *const d1, const domainname *const d2) - { - const mDNSu8 * a = d1->c; - const mDNSu8 * b = d2->c; - const mDNSu8 *const max = d1->c + MAX_DOMAIN_NAME; // Maximum that's valid - - while (*a || *b) - { - if (a + 1 + *a >= max) - { debugf("Malformed domain name (more than 256 characters)"); return(mDNSfalse); } - if (!SameDomainLabel(a, b)) return(mDNSfalse); - a += 1 + *a; - b += 1 + *b; - } - - return(mDNStrue); - } - -mDNSexport mDNSBool SameDomainNameCS(const domainname *const d1, const domainname *const d2) - { - mDNSu16 l1 = DomainNameLength(d1); - mDNSu16 l2 = DomainNameLength(d2); - return(l1 <= MAX_DOMAIN_NAME && l1 == l2 && mDNSPlatformMemSame(d1, d2, l1)); - } - -mDNSexport mDNSBool IsLocalDomain(const domainname *d) - { - // Domains that are defined to be resolved via link-local multicast are: - // local., 254.169.in-addr.arpa., and {8,9,A,B}.E.F.ip6.arpa. - static const domainname *nL = (const domainname*)"\x5" "local"; - static const domainname *nR = (const domainname*)"\x3" "254" "\x3" "169" "\x7" "in-addr" "\x4" "arpa"; - static const domainname *n8 = (const domainname*)"\x1" "8" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; - static const domainname *n9 = (const domainname*)"\x1" "9" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; - static const domainname *nA = (const domainname*)"\x1" "a" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; - static const domainname *nB = (const domainname*)"\x1" "b" "\x1" "e" "\x1" "f" "\x3" "ip6" "\x4" "arpa"; - - const domainname *d1, *d2, *d3, *d4, *d5; // Top-level domain, second-level domain, etc. - d1 = d2 = d3 = d4 = d5 = mDNSNULL; - while (d->c[0]) - { - d5 = d4; d4 = d3; d3 = d2; d2 = d1; d1 = d; - d = (const domainname*)(d->c + 1 + d->c[0]); - } - - if (d1 && SameDomainName(d1, nL)) return(mDNStrue); - if (d4 && SameDomainName(d4, nR)) return(mDNStrue); - if (d5 && SameDomainName(d5, n8)) return(mDNStrue); - if (d5 && SameDomainName(d5, n9)) return(mDNStrue); - if (d5 && SameDomainName(d5, nA)) return(mDNStrue); - if (d5 && SameDomainName(d5, nB)) return(mDNStrue); - return(mDNSfalse); - } - -mDNSexport const mDNSu8 *LastLabel(const domainname *d) - { - const mDNSu8 *p = d->c; - while (d->c[0]) - { - p = d->c; - d = (const domainname*)(d->c + 1 + d->c[0]); - } - return(p); - } - -// Returns length of a domain name INCLUDING the byte for the final null label -// e.g. for the root label "." it returns one -// For the FQDN "com." it returns 5 (length byte, three data bytes, final zero) -// Legal results are 1 (just root label) to 256 (MAX_DOMAIN_NAME) -// If the given domainname is invalid, result is 257 (MAX_DOMAIN_NAME+1) -mDNSexport mDNSu16 DomainNameLengthLimit(const domainname *const name, const mDNSu8 *limit) - { - const mDNSu8 *src = name->c; - while (src < limit && *src <= MAX_DOMAIN_LABEL) - { - if (*src == 0) return((mDNSu16)(src - name->c + 1)); - src += 1 + *src; - } - return(MAX_DOMAIN_NAME+1); - } - -// CompressedDomainNameLength returns the length of a domain name INCLUDING the byte -// for the final null label, e.g. for the root label "." it returns one. -// E.g. for the FQDN "foo.com." it returns 9 -// (length, three data bytes, length, three more data bytes, final zero). -// In the case where a parent domain name is provided, and the given name is a child -// of that parent, CompressedDomainNameLength returns the length of the prefix portion -// of the child name, plus TWO bytes for the compression pointer. -// E.g. for the name "foo.com." with parent "com.", it returns 6 -// (length, three data bytes, two-byte compression pointer). -mDNSexport mDNSu16 CompressedDomainNameLength(const domainname *const name, const domainname *parent) - { - const mDNSu8 *src = name->c; - if (parent && parent->c[0] == 0) parent = mDNSNULL; - while (*src) - { - if (*src > MAX_DOMAIN_LABEL) return(MAX_DOMAIN_NAME+1); - if (parent && SameDomainName((const domainname *)src, parent)) return((mDNSu16)(src - name->c + 2)); - src += 1 + *src; - if (src - name->c >= MAX_DOMAIN_NAME) return(MAX_DOMAIN_NAME+1); - } - return((mDNSu16)(src - name->c + 1)); - } - -// CountLabels() returns number of labels in name, excluding final root label -// (e.g. for "apple.com." CountLabels returns 2.) -mDNSexport int CountLabels(const domainname *d) - { - int count = 0; - const mDNSu8 *ptr; - for (ptr = d->c; *ptr; ptr = ptr + ptr[0] + 1) count++; - return count; - } - -// SkipLeadingLabels skips over the first 'skip' labels in the domainname, -// returning a pointer to the suffix with 'skip' labels removed. -mDNSexport const domainname *SkipLeadingLabels(const domainname *d, int skip) - { - while (skip > 0 && d->c[0]) { d = (const domainname *)(d->c + 1 + d->c[0]); skip--; } - return(d); - } - -// AppendLiteralLabelString appends a single label to an existing (possibly empty) domainname. -// The C string contains the label as-is, with no escaping, etc. -// Any dots in the name are literal dots, not label separators -// If successful, AppendLiteralLabelString returns a pointer to the next unused byte -// in the domainname bufer (i.e. the next byte after the terminating zero). -// If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) -// AppendLiteralLabelString returns mDNSNULL. -mDNSexport mDNSu8 *AppendLiteralLabelString(domainname *const name, const char *cstr) - { - mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name - const mDNSu8 *const lim1 = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero) - const mDNSu8 *const lim2 = ptr + 1 + MAX_DOMAIN_LABEL; - const mDNSu8 *const lim = (lim1 < lim2) ? lim1 : lim2; - mDNSu8 *lengthbyte = ptr++; // Record where the length is going to go - - while (*cstr && ptr < lim) *ptr++ = (mDNSu8)*cstr++; // Copy the data - *lengthbyte = (mDNSu8)(ptr - lengthbyte - 1); // Fill in the length byte - *ptr++ = 0; // Put the null root label on the end - if (*cstr) return(mDNSNULL); // Failure: We didn't successfully consume all input - else return(ptr); // Success: return new value of ptr - } - -// AppendDNSNameString appends zero or more labels to an existing (possibly empty) domainname. -// The C string is in conventional DNS syntax: -// Textual labels, escaped as necessary using the usual DNS '\' notation, separated by dots. -// If successful, AppendDNSNameString returns a pointer to the next unused byte -// in the domainname bufer (i.e. the next byte after the terminating zero). -// If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) -// AppendDNSNameString returns mDNSNULL. -mDNSexport mDNSu8 *AppendDNSNameString(domainname *const name, const char *cstring) - { - const char *cstr = cstring; - mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name - const mDNSu8 *const lim = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero) - while (*cstr && ptr < lim) // While more characters, and space to put them... - { - mDNSu8 *lengthbyte = ptr++; // Record where the length is going to go - if (*cstr == '.') { LogMsg("AppendDNSNameString: Illegal empty label in name \"%s\"", cstring); return(mDNSNULL); } - while (*cstr && *cstr != '.' && ptr < lim) // While we have characters in the label... - { - mDNSu8 c = (mDNSu8)*cstr++; // Read the character - if (c == '\\') // If escape character, check next character - { - c = (mDNSu8)*cstr++; // Assume we'll just take the next character - if (mDNSIsDigit(cstr[-1]) && mDNSIsDigit(cstr[0]) && mDNSIsDigit(cstr[1])) - { // If three decimal digits, - int v0 = cstr[-1] - '0'; // then interpret as three-digit decimal - int v1 = cstr[ 0] - '0'; - int v2 = cstr[ 1] - '0'; - int val = v0 * 100 + v1 * 10 + v2; - if (val <= 255) { c = (mDNSu8)val; cstr += 2; } // If valid three-digit decimal value, use it - } - } - *ptr++ = c; // Write the character - } - if (*cstr) cstr++; // Skip over the trailing dot (if present) - if (ptr - lengthbyte - 1 > MAX_DOMAIN_LABEL) // If illegal label, abort - return(mDNSNULL); - *lengthbyte = (mDNSu8)(ptr - lengthbyte - 1); // Fill in the length byte - } - - *ptr++ = 0; // Put the null root label on the end - if (*cstr) return(mDNSNULL); // Failure: We didn't successfully consume all input - else return(ptr); // Success: return new value of ptr - } - -// AppendDomainLabel appends a single label to a name. -// If successful, AppendDomainLabel returns a pointer to the next unused byte -// in the domainname bufer (i.e. the next byte after the terminating zero). -// If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) -// AppendDomainLabel returns mDNSNULL. -mDNSexport mDNSu8 *AppendDomainLabel(domainname *const name, const domainlabel *const label) - { - int i; - mDNSu8 *ptr = name->c + DomainNameLength(name) - 1; - - // Check label is legal - if (label->c[0] > MAX_DOMAIN_LABEL) return(mDNSNULL); - - // Check that ptr + length byte + data bytes + final zero does not exceed our limit - if (ptr + 1 + label->c[0] + 1 > name->c + MAX_DOMAIN_NAME) return(mDNSNULL); - - for (i=0; i<=label->c[0]; i++) *ptr++ = label->c[i]; // Copy the label data - *ptr++ = 0; // Put the null root label on the end - return(ptr); - } - -mDNSexport mDNSu8 *AppendDomainName(domainname *const name, const domainname *const append) - { - mDNSu8 * ptr = name->c + DomainNameLength(name) - 1; // Find end of current name - const mDNSu8 *const lim = name->c + MAX_DOMAIN_NAME - 1; // Limit of how much we can add (not counting final zero) - const mDNSu8 * src = append->c; - while (src[0]) - { - int i; - if (ptr + 1 + src[0] > lim) return(mDNSNULL); - for (i=0; i<=src[0]; i++) *ptr++ = src[i]; - *ptr = 0; // Put the null root label on the end - src += i; - } - return(ptr); - } - -// MakeDomainLabelFromLiteralString makes a single domain label from a single literal C string (with no escaping). -// If successful, MakeDomainLabelFromLiteralString returns mDNStrue. -// If unable to convert the whole string to a legal domain label (i.e. because length is more than 63 bytes) then -// MakeDomainLabelFromLiteralString makes a legal domain label from the first 63 bytes of the string and returns mDNSfalse. -// In some cases silently truncated oversized names to 63 bytes is acceptable, so the return result may be ignored. -// In other cases silent truncation may not be acceptable, so in those cases the calling function needs to check the return result. -mDNSexport mDNSBool MakeDomainLabelFromLiteralString(domainlabel *const label, const char *cstr) - { - mDNSu8 * ptr = label->c + 1; // Where we're putting it - const mDNSu8 *const limit = label->c + 1 + MAX_DOMAIN_LABEL; // The maximum we can put - while (*cstr && ptr < limit) *ptr++ = (mDNSu8)*cstr++; // Copy the label - label->c[0] = (mDNSu8)(ptr - label->c - 1); // Set the length byte - return(*cstr == 0); // Return mDNStrue if we successfully consumed all input - } - -// MakeDomainNameFromDNSNameString makes a native DNS-format domainname from a C string. -// The C string is in conventional DNS syntax: -// Textual labels, escaped as necessary using the usual DNS '\' notation, separated by dots. -// If successful, MakeDomainNameFromDNSNameString returns a pointer to the next unused byte -// in the domainname bufer (i.e. the next byte after the terminating zero). -// If unable to construct a legal domain name (i.e. label more than 63 bytes, or total more than 256 bytes) -// MakeDomainNameFromDNSNameString returns mDNSNULL. -mDNSexport mDNSu8 *MakeDomainNameFromDNSNameString(domainname *const name, const char *cstr) - { - name->c[0] = 0; // Make an empty domain name - return(AppendDNSNameString(name, cstr)); // And then add this string to it - } - -mDNSexport char *ConvertDomainLabelToCString_withescape(const domainlabel *const label, char *ptr, char esc) - { - const mDNSu8 * src = label->c; // Domain label we're reading - const mDNSu8 len = *src++; // Read length of this (non-null) label - const mDNSu8 *const end = src + len; // Work out where the label ends - if (len > MAX_DOMAIN_LABEL) return(mDNSNULL); // If illegal label, abort - while (src < end) // While we have characters in the label - { - mDNSu8 c = *src++; - if (esc) - { - if (c == '.' || c == esc) // If character is a dot or the escape character - *ptr++ = esc; // Output escape character - else if (c <= ' ') // If non-printing ascii, - { // Output decimal escape sequence - *ptr++ = esc; - *ptr++ = (char) ('0' + (c / 100) ); - *ptr++ = (char) ('0' + (c / 10) % 10); - c = (mDNSu8)('0' + (c ) % 10); - } - } - *ptr++ = (char)c; // Copy the character - } - *ptr = 0; // Null-terminate the string - return(ptr); // and return - } - -// Note: To guarantee that there will be no possible overrun, cstr must be at least MAX_ESCAPED_DOMAIN_NAME (1009 bytes) -mDNSexport char *ConvertDomainNameToCString_withescape(const domainname *const name, char *ptr, char esc) - { - const mDNSu8 *src = name->c; // Domain name we're reading - const mDNSu8 *const max = name->c + MAX_DOMAIN_NAME; // Maximum that's valid - - if (*src == 0) *ptr++ = '.'; // Special case: For root, just write a dot - - while (*src) // While more characters in the domain name - { - if (src + 1 + *src >= max) return(mDNSNULL); - ptr = ConvertDomainLabelToCString_withescape((const domainlabel *)src, ptr, esc); - if (!ptr) return(mDNSNULL); - src += 1 + *src; - *ptr++ = '.'; // Write the dot after the label - } - - *ptr++ = 0; // Null-terminate the string - return(ptr); // and return - } - -// RFC 1034 rules: -// Host names must start with a letter, end with a letter or digit, -// and have as interior characters only letters, digits, and hyphen. -// This was subsequently modified in RFC 1123 to allow the first character to be either a letter or a digit - -mDNSexport void ConvertUTF8PstringToRFC1034HostLabel(const mDNSu8 UTF8Name[], domainlabel *const hostlabel) - { - const mDNSu8 * src = &UTF8Name[1]; - const mDNSu8 *const end = &UTF8Name[1] + UTF8Name[0]; - mDNSu8 * ptr = &hostlabel->c[1]; - const mDNSu8 *const lim = &hostlabel->c[1] + MAX_DOMAIN_LABEL; - while (src < end) - { - // Delete apostrophes from source name - if (src[0] == '\'') { src++; continue; } // Standard straight single quote - if (src + 2 < end && src[0] == 0xE2 && src[1] == 0x80 && src[2] == 0x99) - { src += 3; continue; } // Unicode curly apostrophe - if (ptr < lim) - { - if (mDNSValidHostChar(*src, (ptr > &hostlabel->c[1]), (src < end-1))) *ptr++ = *src; - else if (ptr > &hostlabel->c[1] && ptr[-1] != '-') *ptr++ = '-'; - } - src++; - } - while (ptr > &hostlabel->c[1] && ptr[-1] == '-') ptr--; // Truncate trailing '-' marks - hostlabel->c[0] = (mDNSu8)(ptr - &hostlabel->c[1]); - } - -#define ValidTransportProtocol(X) ( (X)[0] == 4 && (X)[1] == '_' && \ - ((((X)[2] | 0x20) == 'u' && ((X)[3] | 0x20) == 'd') || (((X)[2] | 0x20) == 't' && ((X)[3] | 0x20) == 'c')) && \ - ((X)[4] | 0x20) == 'p') - -mDNSexport mDNSu8 *ConstructServiceName(domainname *const fqdn, - const domainlabel *name, const domainname *type, const domainname *const domain) - { - int i, len; - mDNSu8 *dst = fqdn->c; - const mDNSu8 *src; - const char *errormsg; -#if APPLE_OSX_mDNSResponder - mDNSBool loggedUnderscore = mDNSfalse; - static char typeBuf[MAX_ESCAPED_DOMAIN_NAME]; -#endif - - // In the case where there is no name (and ONLY in that case), - // a single-label subtype is allowed as the first label of a three-part "type" - if (!name && type) - { - const mDNSu8 *s0 = type->c; - if (s0[0] && s0[0] < 0x40) // If legal first label (at least one character, and no more than 63) - { - const mDNSu8 * s1 = s0 + 1 + s0[0]; - if (s1[0] && s1[0] < 0x40) // and legal second label (at least one character, and no more than 63) - { - const mDNSu8 *s2 = s1 + 1 + s1[0]; - if (s2[0] && s2[0] < 0x40 && s2[1+s2[0]] == 0) // and we have three and only three labels - { - static const mDNSu8 SubTypeLabel[5] = "\x04_sub"; - src = s0; // Copy the first label - len = *src; - for (i=0; i <= len; i++) *dst++ = *src++; - for (i=0; i < (int)sizeof(SubTypeLabel); i++) *dst++ = SubTypeLabel[i]; - type = (const domainname *)s1; - - // Special support to enable the DNSServiceBrowse call made by Bonjour Browser - // For these queries, we retract the "._sub" we just added between the subtype and the main type - // Remove after Bonjour Browser is updated to use DNSServiceQueryRecord instead of DNSServiceBrowse - if (SameDomainName((domainname*)s0, (const domainname*)"\x09_services\x07_dns-sd\x04_udp")) - dst -= sizeof(SubTypeLabel); - } - } - } - } - - if (name && name->c[0]) - { - src = name->c; // Put the service name into the domain name - len = *src; - if (len >= 0x40) { errormsg = "Service instance name too long"; goto fail; } - for (i=0; i<=len; i++) *dst++ = *src++; - } - else - name = (domainlabel*)""; // Set this up to be non-null, to avoid errors if we have to call LogMsg() below - - src = type->c; // Put the service type into the domain name - len = *src; - if (len < 2 || len > 16) - { - LogMsg("Bad service type in %#s.%##s%##s Application protocol name must be underscore plus 1-15 characters. " - "See <http://www.dns-sd.org/ServiceTypes.html>", name->c, type->c, domain->c); -#if APPLE_OSX_mDNSResponder - ConvertDomainNameToCString(type, typeBuf); - mDNSASLLog(mDNSNULL, "serviceType.nameTooLong", "noop", typeBuf, ""); -#endif - } - if (len < 2 || len >= 0x40 || (len > 16 && !SameDomainName(domain, &localdomain))) return(mDNSNULL); - if (src[1] != '_') { errormsg = "Application protocol name must begin with underscore"; goto fail; } - for (i=2; i<=len; i++) - { - // Letters and digits are allowed anywhere - if (mDNSIsLetter(src[i]) || mDNSIsDigit(src[i])) continue; - // Hyphens are only allowed as interior characters - // Underscores are not supposed to be allowed at all, but for backwards compatibility with some old products we do allow them, - // with the same rule as hyphens - if ((src[i] == '-' || src[i] == '_') && i > 2 && i < len) - { -#if APPLE_OSX_mDNSResponder - if (src[i] == '_' && loggedUnderscore == mDNSfalse) - { - ConvertDomainNameToCString(type, typeBuf); - mDNSASLLog(mDNSNULL, "serviceType.nameWithUnderscore", "noop", typeBuf, ""); - loggedUnderscore = mDNStrue; - } -#endif - continue; - } - errormsg = "Application protocol name must contain only letters, digits, and hyphens"; -#if APPLE_OSX_mDNSResponder - { - ConvertDomainNameToCString(type, typeBuf); - mDNSASLLog(mDNSNULL, "serviceType.nameWithIllegalCharacters", "noop", typeBuf, ""); - } -#endif - goto fail; - } - for (i=0; i<=len; i++) *dst++ = *src++; - - len = *src; - if (!ValidTransportProtocol(src)) { errormsg = "Transport protocol name must be _udp or _tcp"; goto fail; } - for (i=0; i<=len; i++) *dst++ = *src++; - - if (*src) { errormsg = "Service type must have only two labels"; goto fail; } - - *dst = 0; - if (!domain->c[0]) { errormsg = "Service domain must be non-empty"; goto fail; } - if (SameDomainName(domain, (const domainname*)"\x05" "local" "\x04" "arpa")) - { errormsg = "Illegal domain \"local.arpa.\" Use \"local.\" (or empty string)"; goto fail; } - dst = AppendDomainName(fqdn, domain); - if (!dst) { errormsg = "Service domain too long"; goto fail; } - return(dst); - -fail: - LogMsg("ConstructServiceName: %s: %#s.%##s%##s", errormsg, name->c, type->c, domain->c); - return(mDNSNULL); - } - -// A service name has the form: instance.application-protocol.transport-protocol.domain -// DeconstructServiceName is currently fairly forgiving: It doesn't try to enforce character -// set or length limits for the protocol names, and the final domain is allowed to be empty. -// However, if the given FQDN doesn't contain at least three labels, -// DeconstructServiceName will reject it and return mDNSfalse. -mDNSexport mDNSBool DeconstructServiceName(const domainname *const fqdn, - domainlabel *const name, domainname *const type, domainname *const domain) - { - int i, len; - const mDNSu8 *src = fqdn->c; - const mDNSu8 *max = fqdn->c + MAX_DOMAIN_NAME; - mDNSu8 *dst; - - dst = name->c; // Extract the service name - len = *src; - if (!len) { debugf("DeconstructServiceName: FQDN empty!"); return(mDNSfalse); } - if (len >= 0x40) { debugf("DeconstructServiceName: Instance name too long"); return(mDNSfalse); } - for (i=0; i<=len; i++) *dst++ = *src++; - - dst = type->c; // Extract the service type - len = *src; - if (!len) { debugf("DeconstructServiceName: FQDN contains only one label!"); return(mDNSfalse); } - if (len >= 0x40) { debugf("DeconstructServiceName: Application protocol name too long"); return(mDNSfalse); } - if (src[1] != '_'){ debugf("DeconstructServiceName: No _ at start of application protocol"); return(mDNSfalse); } - for (i=0; i<=len; i++) *dst++ = *src++; - - len = *src; - if (!len) { debugf("DeconstructServiceName: FQDN contains only two labels!"); return(mDNSfalse); } - if (!ValidTransportProtocol(src)) - { debugf("DeconstructServiceName: Transport protocol must be _udp or _tcp"); return(mDNSfalse); } - for (i=0; i<=len; i++) *dst++ = *src++; - *dst++ = 0; // Put terminator on the end of service type - - dst = domain->c; // Extract the service domain - while (*src) - { - len = *src; - if (len >= 0x40) - { debugf("DeconstructServiceName: Label in service domain too long"); return(mDNSfalse); } - if (src + 1 + len + 1 >= max) - { debugf("DeconstructServiceName: Total service domain too long"); return(mDNSfalse); } - for (i=0; i<=len; i++) *dst++ = *src++; - } - *dst++ = 0; // Put the null root label on the end - - return(mDNStrue); - } - -// Notes on UTF-8: -// 0xxxxxxx represents a 7-bit ASCII value from 0x00 to 0x7F -// 10xxxxxx is a continuation byte of a multi-byte character -// 110xxxxx is the first byte of a 2-byte character (11 effective bits; values 0x 80 - 0x 800-1) -// 1110xxxx is the first byte of a 3-byte character (16 effective bits; values 0x 800 - 0x 10000-1) -// 11110xxx is the first byte of a 4-byte character (21 effective bits; values 0x 10000 - 0x 200000-1) -// 111110xx is the first byte of a 5-byte character (26 effective bits; values 0x 200000 - 0x 4000000-1) -// 1111110x is the first byte of a 6-byte character (31 effective bits; values 0x4000000 - 0x80000000-1) -// -// UTF-16 surrogate pairs are used in UTF-16 to encode values larger than 0xFFFF. -// Although UTF-16 surrogate pairs are not supposed to appear in legal UTF-8, we want to be defensive -// about that too. (See <http://www.unicode.org/faq/utf_bom.html#34>, "What are surrogates?") -// The first of pair is a UTF-16 value in the range 0xD800-0xDBFF (11101101 1010xxxx 10xxxxxx in UTF-8), -// and the second is a UTF-16 value in the range 0xDC00-0xDFFF (11101101 1011xxxx 10xxxxxx in UTF-8). - -mDNSexport mDNSu32 TruncateUTF8ToLength(mDNSu8 *string, mDNSu32 length, mDNSu32 max) - { - if (length > max) - { - mDNSu8 c1 = string[max]; // First byte after cut point - mDNSu8 c2 = (max+1 < length) ? string[max+1] : (mDNSu8)0xB0; // Second byte after cut point - length = max; // Trim length down - while (length > 0) - { - // Check if the byte right after the chop point is a UTF-8 continuation byte, - // or if the character right after the chop point is the second of a UTF-16 surrogate pair. - // If so, then we continue to chop more bytes until we get to a legal chop point. - mDNSBool continuation = ((c1 & 0xC0) == 0x80); - mDNSBool secondsurrogate = (c1 == 0xED && (c2 & 0xF0) == 0xB0); - if (!continuation && !secondsurrogate) break; - c2 = c1; - c1 = string[--length]; - } - // Having truncated characters off the end of our string, also cut off any residual white space - while (length > 0 && string[length-1] <= ' ') length--; - } - return(length); - } - -// Returns true if a rich text label ends in " (nnn)", or if an RFC 1034 -// name ends in "-nnn", where n is some decimal number. -mDNSexport mDNSBool LabelContainsSuffix(const domainlabel *const name, const mDNSBool RichText) - { - mDNSu16 l = name->c[0]; - - if (RichText) - { - if (l < 4) return mDNSfalse; // Need at least " (2)" - if (name->c[l--] != ')') return mDNSfalse; // Last char must be ')' - if (!mDNSIsDigit(name->c[l])) return mDNSfalse; // Preceeded by a digit - l--; - while (l > 2 && mDNSIsDigit(name->c[l])) l--; // Strip off digits - return (name->c[l] == '(' && name->c[l - 1] == ' '); - } - else - { - if (l < 2) return mDNSfalse; // Need at least "-2" - if (!mDNSIsDigit(name->c[l])) return mDNSfalse; // Last char must be a digit - l--; - while (l > 2 && mDNSIsDigit(name->c[l])) l--; // Strip off digits - return (name->c[l] == '-'); - } - } - -// removes an auto-generated suffix (appended on a name collision) from a label. caller is -// responsible for ensuring that the label does indeed contain a suffix. returns the number -// from the suffix that was removed. -mDNSexport mDNSu32 RemoveLabelSuffix(domainlabel *name, mDNSBool RichText) - { - mDNSu32 val = 0, multiplier = 1; - - // Chop closing parentheses from RichText suffix - if (RichText && name->c[0] >= 1 && name->c[name->c[0]] == ')') name->c[0]--; - - // Get any existing numerical suffix off the name - while (mDNSIsDigit(name->c[name->c[0]])) - { val += (name->c[name->c[0]] - '0') * multiplier; multiplier *= 10; name->c[0]--; } - - // Chop opening parentheses or dash from suffix - if (RichText) - { - if (name->c[0] >= 2 && name->c[name->c[0]] == '(' && name->c[name->c[0]-1] == ' ') name->c[0] -= 2; - } - else - { - if (name->c[0] >= 1 && name->c[name->c[0]] == '-') name->c[0] -= 1; - } - - return(val); - } - -// appends a numerical suffix to a label, with the number following a whitespace and enclosed -// in parentheses (rich text) or following two consecutive hyphens (RFC 1034 domain label). -mDNSexport void AppendLabelSuffix(domainlabel *const name, mDNSu32 val, const mDNSBool RichText) - { - mDNSu32 divisor = 1, chars = 2; // Shortest possible RFC1034 name suffix is 2 characters ("-2") - if (RichText) chars = 4; // Shortest possible RichText suffix is 4 characters (" (2)") - - // Truncate trailing spaces from RichText names - if (RichText) while (name->c[name->c[0]] == ' ') name->c[0]--; - - while (divisor < 0xFFFFFFFFUL/10 && val >= divisor * 10) { divisor *= 10; chars++; } - - name->c[0] = (mDNSu8) TruncateUTF8ToLength(name->c+1, name->c[0], MAX_DOMAIN_LABEL - chars); - - if (RichText) { name->c[++name->c[0]] = ' '; name->c[++name->c[0]] = '('; } - else { name->c[++name->c[0]] = '-'; } - - while (divisor) - { - name->c[++name->c[0]] = (mDNSu8)('0' + val / divisor); - val %= divisor; - divisor /= 10; - } - - if (RichText) name->c[++name->c[0]] = ')'; - } - -mDNSexport void IncrementLabelSuffix(domainlabel *name, mDNSBool RichText) - { - mDNSu32 val = 0; - - if (LabelContainsSuffix(name, RichText)) - val = RemoveLabelSuffix(name, RichText); - - // If no existing suffix, start by renaming "Foo" as "Foo (2)" or "Foo-2" as appropriate. - // If existing suffix in the range 2-9, increment it. - // If we've had ten conflicts already, there are probably too many hosts trying to use the same name, - // so add a random increment to improve the chances of finding an available name next time. - if (val == 0) val = 2; - else if (val < 10) val++; - else val += 1 + mDNSRandom(99); - - AppendLabelSuffix(name, val, RichText); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - Resource Record Utility Functions -#endif - -// Set up a AuthRecord with sensible default values. -// These defaults may be overwritten with new values before mDNS_Register is called -mDNSexport void mDNS_SetupResourceRecord(AuthRecord *rr, RData *RDataStorage, mDNSInterfaceID InterfaceID, - mDNSu16 rrtype, mDNSu32 ttl, mDNSu8 RecordType, AuthRecType artype, mDNSRecordCallback Callback, void *Context) - { - // - // LocalOnly auth record can be created with LocalOnly InterfaceID or a valid InterfaceID. - // Most of the applications normally create with LocalOnly InterfaceID and we store them as - // such, so that we can deliver the response to questions that specify LocalOnly InterfaceID. - // LocalOnly resource records can also be created with valid InterfaceID which happens today - // when we create LocalOnly records for /etc/hosts. - - if (InterfaceID == mDNSInterface_LocalOnly && artype != AuthRecordLocalOnly) - { - LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch LocalOnly record InterfaceID %p called with artype %d", InterfaceID, artype); - return; - } - else if (InterfaceID == mDNSInterface_P2P && artype != AuthRecordP2P) - { - LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch P2P record InterfaceID %p called with artype %d", InterfaceID, artype); - return; - } - else if (!InterfaceID && (artype == AuthRecordP2P || artype == AuthRecordLocalOnly)) - { - LogMsg("mDNS_SetupResourceRecord: ERROR!! Mismatch InterfaceAny record InterfaceID %p called with artype %d", InterfaceID, artype); - return; - } - - // Don't try to store a TTL bigger than we can represent in platform time units - if (ttl > 0x7FFFFFFFUL / mDNSPlatformOneSecond) - ttl = 0x7FFFFFFFUL / mDNSPlatformOneSecond; - else if (ttl == 0) // And Zero TTL is illegal - ttl = DefaultTTLforRRType(rrtype); - - // Field Group 1: The actual information pertaining to this resource record - rr->resrec.RecordType = RecordType; - rr->resrec.InterfaceID = InterfaceID; - rr->resrec.name = &rr->namestorage; - rr->resrec.rrtype = rrtype; - rr->resrec.rrclass = kDNSClass_IN; - rr->resrec.rroriginalttl = ttl; - rr->resrec.rDNSServer = mDNSNULL; -// rr->resrec.rdlength = MUST set by client and/or in mDNS_Register_internal -// rr->resrec.rdestimate = set in mDNS_Register_internal -// rr->resrec.rdata = MUST be set by client - - if (RDataStorage) - rr->resrec.rdata = RDataStorage; - else - { - rr->resrec.rdata = &rr->rdatastorage; - rr->resrec.rdata->MaxRDLength = sizeof(RDataBody); - } - - // Field Group 2: Persistent metadata for Authoritative Records - rr->Additional1 = mDNSNULL; - rr->Additional2 = mDNSNULL; - rr->DependentOn = mDNSNULL; - rr->RRSet = mDNSNULL; - rr->RecordCallback = Callback; - rr->RecordContext = Context; - - rr->AutoTarget = Target_Manual; - rr->AllowRemoteQuery = mDNSfalse; - rr->ForceMCast = mDNSfalse; - - rr->WakeUp = zeroOwner; - rr->AddressProxy = zeroAddr; - rr->TimeRcvd = 0; - rr->TimeExpire = 0; - rr->ARType = artype; - - // Field Group 3: Transient state for Authoritative Records (set in mDNS_Register_internal) - // Field Group 4: Transient uDNS state for Authoritative Records (set in mDNS_Register_internal) - - // For now, until the uDNS code is fully integrated, it's helpful to zero the uDNS state fields here too, just in case - // (e.g. uDNS_RegisterService short-circuits the usual mDNS_Register_internal record registration calls, so a bunch - // of fields don't get set up properly. In particular, if we don't zero rr->QueuedRData then the uDNS code crashes.) - rr->state = regState_Zero; - rr->uselease = 0; - rr->expire = 0; - rr->Private = 0; - rr->updateid = zeroID; - rr->zone = rr->resrec.name; - rr->nta = mDNSNULL; - rr->tcp = mDNSNULL; - rr->OrigRData = 0; - rr->OrigRDLen = 0; - rr->InFlightRData = 0; - rr->InFlightRDLen = 0; - rr->QueuedRData = 0; - rr->QueuedRDLen = 0; - mDNSPlatformMemZero(&rr->NATinfo, sizeof(rr->NATinfo)); - rr->SRVChanged = mDNSfalse; - rr->mState = mergeState_Zero; - - rr->namestorage.c[0] = 0; // MUST be set by client before calling mDNS_Register() - } - -mDNSexport void mDNS_SetupQuestion(DNSQuestion *const q, const mDNSInterfaceID InterfaceID, const domainname *const name, - const mDNSu16 qtype, mDNSQuestionCallback *const callback, void *const context) - { - q->InterfaceID = InterfaceID; - q->Target = zeroAddr; - AssignDomainName(&q->qname, name); - q->qtype = qtype; - q->qclass = kDNSClass_IN; - q->LongLived = (qtype == kDNSType_PTR); - q->ExpectUnique = (qtype != kDNSType_PTR); - q->ForceMCast = mDNSfalse; - q->ReturnIntermed = mDNSfalse; - q->SuppressUnusable = mDNSfalse; - q->SearchListIndex = 0; - q->AppendSearchDomains = 0; - q->RetryWithSearchDomains = mDNSfalse; - q->TimeoutQuestion = 0; - q->WakeOnResolve = 0; - q->qnameOrig = mDNSNULL; - q->QuestionCallback = callback; - q->QuestionContext = context; - } - -mDNSexport mDNSu32 RDataHashValue(const ResourceRecord *const rr) - { - int len = rr->rdlength; - const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data; - switch(rr->rrtype) - { - case kDNSType_NS: - case kDNSType_CNAME: - case kDNSType_PTR: - case kDNSType_DNAME: return DomainNameHashValue(&rdb->name); - - case kDNSType_SOA: return rdb->soa.serial + - rdb->soa.refresh + - rdb->soa.retry + - rdb->soa.expire + - rdb->soa.min + - DomainNameHashValue(&rdb->soa.mname) + - DomainNameHashValue(&rdb->soa.rname); - - case kDNSType_MX: - case kDNSType_AFSDB: - case kDNSType_RT: - case kDNSType_KX: return DomainNameHashValue(&rdb->mx.exchange); - - case kDNSType_RP: return DomainNameHashValue(&rdb->rp.mbox) + DomainNameHashValue(&rdb->rp.txt); - - case kDNSType_PX: return DomainNameHashValue(&rdb->px.map822) + DomainNameHashValue(&rdb->px.mapx400); - - case kDNSType_SRV: return DomainNameHashValue(&rdb->srv.target); - - case kDNSType_OPT: return 0; // OPT is a pseudo-RR container structure; makes no sense to compare - - case kDNSType_NSEC: len = sizeof(rdataNSEC); // Use in-memory length of 32, and fall through default checksum computation below - - default: - { - mDNSu32 sum = 0; - int i; - for (i=0; i+1 < len; i+=2) - { - sum += (((mDNSu32)(rdb->data[i])) << 8) | rdb->data[i+1]; - sum = (sum<<3) | (sum>>29); - } - if (i < len) - { - sum += ((mDNSu32)(rdb->data[i])) << 8; - } - return(sum); - } - } - } - -// r1 has to be a full ResourceRecord including rrtype and rdlength -// r2 is just a bare RDataBody, which MUST be the same rrtype and rdlength as r1 -mDNSexport mDNSBool SameRDataBody(const ResourceRecord *const r1, const RDataBody *const r2, DomainNameComparisonFn *samename) - { - const RDataBody2 *const b1 = (RDataBody2 *)r1->rdata->u.data; - const RDataBody2 *const b2 = (RDataBody2 *)r2; - switch(r1->rrtype) - { - case kDNSType_NS: - case kDNSType_CNAME: - case kDNSType_PTR: - case kDNSType_DNAME:return(SameDomainName(&b1->name, &b2->name)); - - case kDNSType_SOA: return(mDNSBool)( b1->soa.serial == b2->soa.serial && - b1->soa.refresh == b2->soa.refresh && - b1->soa.retry == b2->soa.retry && - b1->soa.expire == b2->soa.expire && - b1->soa.min == b2->soa.min && - samename(&b1->soa.mname, &b2->soa.mname) && - samename(&b1->soa.rname, &b2->soa.rname)); - - case kDNSType_MX: - case kDNSType_AFSDB: - case kDNSType_RT: - case kDNSType_KX: return(mDNSBool)( b1->mx.preference == b2->mx.preference && - samename(&b1->mx.exchange, &b2->mx.exchange)); - - case kDNSType_RP: return(mDNSBool)( samename(&b1->rp.mbox, &b2->rp.mbox) && - samename(&b1->rp.txt, &b2->rp.txt)); - - case kDNSType_PX: return(mDNSBool)( b1->px.preference == b2->px.preference && - samename(&b1->px.map822, &b2->px.map822) && - samename(&b1->px.mapx400, &b2->px.mapx400)); - - case kDNSType_SRV: return(mDNSBool)( b1->srv.priority == b2->srv.priority && - b1->srv.weight == b2->srv.weight && - mDNSSameIPPort(b1->srv.port, b2->srv.port) && - samename(&b1->srv.target, &b2->srv.target)); - - case kDNSType_OPT: return mDNSfalse; // OPT is a pseudo-RR container structure; makes no sense to compare - - case kDNSType_NSEC: return(mDNSPlatformMemSame(b1->data, b2->data, sizeof(rdataNSEC))); - - default: return(mDNSPlatformMemSame(b1->data, b2->data, r1->rdlength)); - } - } - -// ResourceRecordAnswersQuestion returns mDNStrue if the given resource record is a valid answer to the given question. -// SameNameRecordAnswersQuestion is the same, except it skips the expensive SameDomainName() call. -// SameDomainName() is generally cheap when the names don't match, but expensive when they do match, -// because it has to check all the way to the end of the names to be sure. -// In cases where we know in advance that the names match it's especially advantageous to skip the -// SameDomainName() call because that's precisely the time when it's most expensive and least useful. - -mDNSexport mDNSBool SameNameRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q) - { - // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records - // are handled in LocalOnlyRecordAnswersQuestion - if ((rr->InterfaceID == mDNSInterface_LocalOnly) || (rr->InterfaceID == mDNSInterface_P2P)) - { - LogMsg("SameNameRecordAnswersQuestion: ERROR!! called with LocalOnly ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID); - return mDNSfalse; - } - if (rr->InterfaceID && - q ->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && - rr->InterfaceID != q->InterfaceID) return(mDNSfalse); - - // Resource record received via unicast, the DNSServer entries should match ? - if (!rr->InterfaceID && rr->rDNSServer != q->qDNSServer) return(mDNSfalse); - - // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question - if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); - - // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. - if (!RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); - if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); - - return(mDNStrue); - } - -mDNSexport mDNSBool ResourceRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q) - { - // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records - // are handled in LocalOnlyRecordAnswersQuestion - if ((rr->InterfaceID == mDNSInterface_LocalOnly) || (rr->InterfaceID == mDNSInterface_P2P)) - { - LogMsg("ResourceRecordAnswersQuestion: ERROR!! called with LocalOnly/P2P ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID); - return mDNSfalse; - } - - if (rr->InterfaceID && - q ->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && - rr->InterfaceID != q->InterfaceID) return(mDNSfalse); - - // Resource record received via unicast, the DNSServer entries should match ? - if (!rr->InterfaceID && rr->rDNSServer != q->qDNSServer) return(mDNSfalse); - - // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question. - if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); - - // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. - if (!RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); - if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); - - return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); - } - -// We have a separate function to handle LocalOnly AuthRecords because they can be created with -// a valid InterfaceID (e.g., scoped /etc/hosts) and can be used to answer unicast questions unlike -// multicast resource records (which has a valid InterfaceID) which can't be used to answer -// unicast questions. ResourceRecordAnswersQuestion/SameNameRecordAnswersQuestion can't tell whether -// a resource record is multicast or LocalOnly by just looking at the ResourceRecord because -// LocalOnly records are truly identified by ARType in the AuthRecord. As P2P and LocalOnly record -// are kept in the same hash table, we use the same function to make it easy for the callers when -// they walk the hash table to answer LocalOnly/P2P questions -// -mDNSexport mDNSBool LocalOnlyRecordAnswersQuestion(AuthRecord *const ar, const DNSQuestion *const q) - { - ResourceRecord *rr = &ar->resrec; - - // mDNSInterface_Any questions can be answered with LocalOnly/P2P records in this function. AuthRecord_Any - // records are handled in ResourceRecordAnswersQuestion/SameNameRecordAnswersQuestion - if (RRAny(ar)) - { - LogMsg("LocalOnlyRecordAnswersQuestion: ERROR!! called with regular AuthRecordAny %##s", rr->name->c); - return mDNSfalse; - } - - // Questions with mDNSInterface_LocalOnly InterfaceID should be answered with all resource records that are - // *local* to the machine. These include resource records that have InterfaceID set to mDNSInterface_LocalOnly, - // mDNSInterface_Any and any other real InterfaceID. Hence, LocalOnly questions should not be checked against - // the InterfaceID in the resource record. - // - // mDNSInterface_Unicast does not indicate any scope and hence treat them like mDNSInterface_Any. - - if (rr->InterfaceID && - q->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && q->InterfaceID != mDNSInterface_Unicast && - rr->InterfaceID != q->InterfaceID) return(mDNSfalse); - - // Entries in /etc/hosts are added as LocalOnly resource records. The LocalOnly resource records - // may have a scope e.g., fe80::1%en0. The question may be scoped or not: the InterfaceID may be set - // to mDNSInterface_Any, mDNSInterface_LocalOnly or a real InterfaceID (scoped). - // - // 1) Question: Any, LocalOnly Record: no scope. This question should be answered with this record. - // - // 2) Question: Any, LocalOnly Record: scoped. This question should be answered with the record because - // traditionally applications never specify scope e.g., getaddrinfo, but need to be able - // to get to /etc/hosts entries. - // - // 3) Question: Scoped (LocalOnly or InterfaceID), LocalOnly Record: no scope. This is the inverse of (2). - // If we register a LocalOnly record, we need to answer a LocalOnly question. If the /etc/hosts has a - // non scoped entry, it may not make sense to answer a scoped question. But we can't tell these two - // cases apart. As we currently answer LocalOnly question with LocalOnly record, we continue to do so. - // - // 4) Question: Scoped (LocalOnly or InterfaceID), LocalOnly Record: scoped. LocalOnly questions should be - // answered with any resource record where as if it has a valid InterfaceID, the scope should match. - // - // (1) and (2) is bypassed because we check for a non-NULL InterfaceID above. For (3), the InterfaceID is NULL - // and hence bypassed above. For (4) we bypassed LocalOnly questions and checked the scope of the record - // against the question. - // - // For P2P, InterfaceIDs of the question and the record should match. - - // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question. - // LocalOnly authoritative answers are exempt. LocalOnly authoritative answers are used for /etc/host entries. - // We don't want a local process to be able to create a fake LocalOnly address record for "www.bigbank.com" which would then - // cause other applications (e.g. Safari) to connect to the wrong address. The rpc to register records filters out records - // with names that don't end in local and have mDNSInterface_LocalOnly set. - // - // Note: The check is bypassed for LocalOnly and for P2P it is not needed as only .local records are registered and for - // a question to match its names, it also has to end in .local and that question can't be a unicast question (See - // Question_uDNS macro and its usage). As P2P does not enforce .local only registrations we still make this check - // and also makes it future proof. - - if (ar->ARType != AuthRecordLocalOnly && rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); - - // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. - if (!RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); - if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); - - return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); - } - -mDNSexport mDNSBool AnyTypeRecordAnswersQuestion(const ResourceRecord *const rr, const DNSQuestion *const q) - { - // LocalOnly/P2P questions can be answered with AuthRecordAny in this function. LocalOnly/P2P records - // are handled in LocalOnlyRecordAnswersQuestion - if ((rr->InterfaceID == mDNSInterface_LocalOnly) || (rr->InterfaceID == mDNSInterface_P2P)) - { - LogMsg("AnyTypeRecordAnswersQuestion: ERROR!! called with LocalOnly ResourceRecord %p, Question %p", rr->InterfaceID, q->InterfaceID); - return mDNSfalse; - } - if (rr->InterfaceID && - q ->InterfaceID && q->InterfaceID != mDNSInterface_LocalOnly && - rr->InterfaceID != q->InterfaceID) return(mDNSfalse); - - // Resource record received via unicast, the DNSServer entries should match ? - // Note that Auth Records are normally setup with NULL InterfaceID and - // both the DNSServers are assumed to be NULL in that case - if (!rr->InterfaceID && rr->rDNSServer != q->qDNSServer) return(mDNSfalse); - - // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question - if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); - - if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); - - return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); - } - -// This is called with both unicast resource record and multicast resource record. The question that -// received the unicast response could be the regular unicast response from a DNS server or a response -// to a mDNS QU query. The main reason we need this function is that we can't compare DNSServers between the -// question and the resource record because the resource record is not completely initialized in -// mDNSCoreReceiveResponse when this function is called. -mDNSexport mDNSBool ResourceRecordAnswersUnicastResponse(const ResourceRecord *const rr, const DNSQuestion *const q) - { - // For resource records created using multicast, the InterfaceIDs have to match - if (rr->InterfaceID && - q->InterfaceID && rr->InterfaceID != q->InterfaceID) return(mDNSfalse); - - // If ResourceRecord received via multicast, but question was unicast, then shouldn't use record to answer this question. - if (rr->InterfaceID && !mDNSOpaque16IsZero(q->TargetQID)) return(mDNSfalse); - - // RR type CNAME matches any query type. QTYPE ANY matches any RR type. QCLASS ANY matches any RR class. - if (!RRTypeAnswersQuestionType(rr,q->qtype)) return(mDNSfalse); - - if (rr->rrclass != q->qclass && q->qclass != kDNSQClass_ANY) return(mDNSfalse); - - return(rr->namehash == q->qnamehash && SameDomainName(rr->name, &q->qname)); - } - -mDNSexport mDNSu16 GetRDLength(const ResourceRecord *const rr, mDNSBool estimate) - { - const RDataBody2 *const rd = (RDataBody2 *)rr->rdata->u.data; - const domainname *const name = estimate ? rr->name : mDNSNULL; - if (rr->rrclass == kDNSQClass_ANY) return(rr->rdlength); // Used in update packets to mean "Delete An RRset" (RFC 2136) - else switch (rr->rrtype) - { - case kDNSType_A: return(sizeof(rd->ipv4)); - - case kDNSType_NS: - case kDNSType_CNAME: - case kDNSType_PTR: - case kDNSType_DNAME:return(CompressedDomainNameLength(&rd->name, name)); - - case kDNSType_SOA: return(mDNSu16)(CompressedDomainNameLength(&rd->soa.mname, name) + - CompressedDomainNameLength(&rd->soa.rname, name) + - 5 * sizeof(mDNSOpaque32)); - - case kDNSType_NULL: - case kDNSType_TSIG: - case kDNSType_TXT: - case kDNSType_X25: - case kDNSType_ISDN: - case kDNSType_LOC: - case kDNSType_DHCID:return(rr->rdlength); // Not self-describing, so have to just trust rdlength - - case kDNSType_HINFO:return(mDNSu16)(2 + (int)rd->data[0] + (int)rd->data[1 + (int)rd->data[0]]); - - case kDNSType_MX: - case kDNSType_AFSDB: - case kDNSType_RT: - case kDNSType_KX: return(mDNSu16)(2 + CompressedDomainNameLength(&rd->mx.exchange, name)); - - case kDNSType_RP: return(mDNSu16)(CompressedDomainNameLength(&rd->rp.mbox, name) + - CompressedDomainNameLength(&rd->rp.txt, name)); - - case kDNSType_PX: return(mDNSu16)(2 + CompressedDomainNameLength(&rd->px.map822, name) + - CompressedDomainNameLength(&rd->px.mapx400, name)); - - case kDNSType_AAAA: return(sizeof(rd->ipv6)); - - case kDNSType_SRV: return(mDNSu16)(6 + CompressedDomainNameLength(&rd->srv.target, name)); - - case kDNSType_OPT: return(rr->rdlength); - - case kDNSType_NSEC: { - int i; - for (i=sizeof(rdataNSEC); i>0; i--) if (rd->nsec.bitmap[i-1]) break; - // For our simplified use of NSEC synthetic records: - // nextname is always the record's own name, - // and if we have at least one record type that exists, - // - the block number is always 0, - // - the count byte is a value in the range 1-32, - // - followed by the 1-32 data bytes - return(mDNSu16)((estimate ? 2 : DomainNameLength(rr->name)) + (i ? (2 + i) : 0)); - } - - default: debugf("Warning! Don't know how to get length of resource type %d", rr->rrtype); - return(rr->rdlength); - } - } - -// When a local client registers (or updates) a record, we use this routine to do some simple validation checks -// to help reduce the risk of bogus malformed data on the network -mDNSexport mDNSBool ValidateRData(const mDNSu16 rrtype, const mDNSu16 rdlength, const RData *const rd) - { - mDNSu16 len; - - switch(rrtype) - { - case kDNSType_A: return(rdlength == sizeof(mDNSv4Addr)); - - case kDNSType_NS: // Same as PTR - case kDNSType_MD: // Same as PTR - case kDNSType_MF: // Same as PTR - case kDNSType_CNAME:// Same as PTR - //case kDNSType_SOA not checked - case kDNSType_MB: // Same as PTR - case kDNSType_MG: // Same as PTR - case kDNSType_MR: // Same as PTR - //case kDNSType_NULL not checked (no specified format, so always valid) - //case kDNSType_WKS not checked - case kDNSType_PTR: len = DomainNameLengthLimit(&rd->u.name, rd->u.data + rdlength); - return(len <= MAX_DOMAIN_NAME && rdlength == len); - - case kDNSType_HINFO:// Same as TXT (roughly) - case kDNSType_MINFO:// Same as TXT (roughly) - case kDNSType_TXT: if (!rdlength) return(mDNSfalse); // TXT record has to be at least one byte (RFC 1035) - { - const mDNSu8 *ptr = rd->u.txt.c; - const mDNSu8 *end = rd->u.txt.c + rdlength; - while (ptr < end) ptr += 1 + ptr[0]; - return (ptr == end); - } - - case kDNSType_AAAA: return(rdlength == sizeof(mDNSv6Addr)); - - case kDNSType_MX: // Must be at least two-byte preference, plus domainname - // Call to DomainNameLengthLimit() implicitly enforces both requirements for us - len = DomainNameLengthLimit(&rd->u.mx.exchange, rd->u.data + rdlength); - return(len <= MAX_DOMAIN_NAME && rdlength == 2+len); - - case kDNSType_SRV: // Must be at least priority+weight+port, plus domainname - // Call to DomainNameLengthLimit() implicitly enforces both requirements for us - len = DomainNameLengthLimit(&rd->u.srv.target, rd->u.data + rdlength); - return(len <= MAX_DOMAIN_NAME && rdlength == 6+len); - - //case kDNSType_NSEC not checked - - default: return(mDNStrue); // Allow all other types without checking - } - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - DNS Message Creation Functions -#endif - -mDNSexport void InitializeDNSMessage(DNSMessageHeader *h, mDNSOpaque16 id, mDNSOpaque16 flags) - { - h->id = id; - h->flags = flags; - h->numQuestions = 0; - h->numAnswers = 0; - h->numAuthorities = 0; - h->numAdditionals = 0; - } - -mDNSexport const mDNSu8 *FindCompressionPointer(const mDNSu8 *const base, const mDNSu8 *const end, const mDNSu8 *const domname) - { - const mDNSu8 *result = end - *domname - 1; - - if (*domname == 0) return(mDNSNULL); // There's no point trying to match just the root label - - // This loop examines each possible starting position in packet, starting end of the packet and working backwards - while (result >= base) - { - // If the length byte and first character of the label match, then check further to see - // if this location in the packet will yield a useful name compression pointer. - if (result[0] == domname[0] && result[1] == domname[1]) - { - const mDNSu8 *name = domname; - const mDNSu8 *targ = result; - while (targ + *name < end) - { - // First see if this label matches - int i; - const mDNSu8 *pointertarget; - for (i=0; i <= *name; i++) if (targ[i] != name[i]) break; - if (i <= *name) break; // If label did not match, bail out - targ += 1 + *name; // Else, did match, so advance target pointer - name += 1 + *name; // and proceed to check next label - if (*name == 0 && *targ == 0) return(result); // If no more labels, we found a match! - if (*name == 0) break; // If no more labels to match, we failed, so bail out - - // The label matched, so now follow the pointer (if appropriate) and then see if the next label matches - if (targ[0] < 0x40) continue; // If length value, continue to check next label - if (targ[0] < 0xC0) break; // If 40-BF, not valid - if (targ+1 >= end) break; // Second byte not present! - pointertarget = base + (((mDNSu16)(targ[0] & 0x3F)) << 8) + targ[1]; - if (targ < pointertarget) break; // Pointertarget must point *backwards* in the packet - if (pointertarget[0] >= 0x40) break; // Pointertarget must point to a valid length byte - targ = pointertarget; - } - } - result--; // We failed to match at this search position, so back up the tentative result pointer and try again - } - return(mDNSNULL); - } - -// Put a string of dot-separated labels as length-prefixed labels -// domainname is a fully-qualified name (i.e. assumed to be ending in a dot, even if it doesn't) -// msg points to the message we're building (pass mDNSNULL if we don't want to use compression pointers) -// end points to the end of the message so far -// ptr points to where we want to put the name -// limit points to one byte past the end of the buffer that we must not overrun -// domainname is the name to put -mDNSexport mDNSu8 *putDomainNameAsLabels(const DNSMessage *const msg, - mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name) - { - const mDNSu8 *const base = (const mDNSu8 *)msg; - const mDNSu8 * np = name->c; - const mDNSu8 *const max = name->c + MAX_DOMAIN_NAME; // Maximum that's valid - const mDNSu8 * pointer = mDNSNULL; - const mDNSu8 *const searchlimit = ptr; - - if (!ptr) { LogMsg("putDomainNameAsLabels %##s ptr is null", name->c); return(mDNSNULL); } - - if (!*np) // If just writing one-byte root label, make sure we have space for that - { - if (ptr >= limit) return(mDNSNULL); - } - else // else, loop through writing labels and/or a compression offset - { - do { - if (*np > MAX_DOMAIN_LABEL) - { LogMsg("Malformed domain name %##s (label more than 63 bytes)", name->c); return(mDNSNULL); } - - // This check correctly allows for the final trailing root label: - // e.g. - // Suppose our domain name is exactly 256 bytes long, including the final trailing root label. - // Suppose np is now at name->c[249], and we're about to write our last non-null label ("local"). - // We know that max will be at name->c[256] - // That means that np + 1 + 5 == max - 1, so we (just) pass the "if" test below, write our - // six bytes, then exit the loop, write the final terminating root label, and the domain - // name we've written is exactly 256 bytes long, exactly at the correct legal limit. - // If the name is one byte longer, then we fail the "if" test below, and correctly bail out. - if (np + 1 + *np >= max) - { LogMsg("Malformed domain name %##s (more than 256 bytes)", name->c); return(mDNSNULL); } - - if (base) pointer = FindCompressionPointer(base, searchlimit, np); - if (pointer) // Use a compression pointer if we can - { - const mDNSu16 offset = (mDNSu16)(pointer - base); - if (ptr+2 > limit) return(mDNSNULL); // If we don't have two bytes of space left, give up - *ptr++ = (mDNSu8)(0xC0 | (offset >> 8)); - *ptr++ = (mDNSu8)( offset & 0xFF); - return(ptr); - } - else // Else copy one label and try again - { - int i; - mDNSu8 len = *np++; - // If we don't at least have enough space for this label *plus* a terminating zero on the end, give up - if (ptr + 1 + len >= limit) return(mDNSNULL); - *ptr++ = len; - for (i=0; i<len; i++) *ptr++ = *np++; - } - } while (*np); // While we've got characters remaining in the name, continue - } - - *ptr++ = 0; // Put the final root label - return(ptr); - } - -mDNSlocal mDNSu8 *putVal16(mDNSu8 *ptr, mDNSu16 val) - { - ptr[0] = (mDNSu8)((val >> 8 ) & 0xFF); - ptr[1] = (mDNSu8)((val ) & 0xFF); - return ptr + sizeof(mDNSOpaque16); - } - -mDNSlocal mDNSu8 *putVal32(mDNSu8 *ptr, mDNSu32 val) - { - ptr[0] = (mDNSu8)((val >> 24) & 0xFF); - ptr[1] = (mDNSu8)((val >> 16) & 0xFF); - ptr[2] = (mDNSu8)((val >> 8) & 0xFF); - ptr[3] = (mDNSu8)((val ) & 0xFF); - return ptr + sizeof(mDNSu32); - } - -// msg points to the message we're building (pass mDNSNULL if we don't want to use compression pointers) -mDNSexport mDNSu8 *putRData(const DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const ResourceRecord *const rr) - { - const RDataBody2 *const rdb = (RDataBody2 *)rr->rdata->u.data; - switch (rr->rrtype) - { - case kDNSType_A: if (rr->rdlength != 4) - { debugf("putRData: Illegal length %d for kDNSType_A", rr->rdlength); return(mDNSNULL); } - if (ptr + 4 > limit) return(mDNSNULL); - *ptr++ = rdb->ipv4.b[0]; - *ptr++ = rdb->ipv4.b[1]; - *ptr++ = rdb->ipv4.b[2]; - *ptr++ = rdb->ipv4.b[3]; - return(ptr); - - case kDNSType_NS: - case kDNSType_CNAME: - case kDNSType_PTR: - case kDNSType_DNAME:return(putDomainNameAsLabels(msg, ptr, limit, &rdb->name)); - - case kDNSType_SOA: ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->soa.mname); - if (!ptr) return(mDNSNULL); - ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->soa.rname); - if (!ptr || ptr + 20 > limit) return(mDNSNULL); - ptr = putVal32(ptr, rdb->soa.serial); - ptr = putVal32(ptr, rdb->soa.refresh); - ptr = putVal32(ptr, rdb->soa.retry); - ptr = putVal32(ptr, rdb->soa.expire); - ptr = putVal32(ptr, rdb->soa.min); - return(ptr); - - case kDNSType_NULL: - case kDNSType_HINFO: - case kDNSType_TSIG: - case kDNSType_TXT: - case kDNSType_X25: - case kDNSType_ISDN: - case kDNSType_LOC: - case kDNSType_DHCID:if (ptr + rr->rdlength > limit) return(mDNSNULL); - mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength); - return(ptr + rr->rdlength); - - case kDNSType_MX: - case kDNSType_AFSDB: - case kDNSType_RT: - case kDNSType_KX: if (ptr + 3 > limit) return(mDNSNULL); - ptr = putVal16(ptr, rdb->mx.preference); - return(putDomainNameAsLabels(msg, ptr, limit, &rdb->mx.exchange)); - - case kDNSType_RP: ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->rp.mbox); - if (!ptr) return(mDNSNULL); - ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->rp.txt); - return(ptr); - - case kDNSType_PX: if (ptr + 5 > limit) return(mDNSNULL); - ptr = putVal16(ptr, rdb->px.preference); - ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->px.map822); - if (!ptr) return(mDNSNULL); - ptr = putDomainNameAsLabels(msg, ptr, limit, &rdb->px.mapx400); - return(ptr); - - case kDNSType_AAAA: if (rr->rdlength != sizeof(rdb->ipv6)) - { debugf("putRData: Illegal length %d for kDNSType_AAAA", rr->rdlength); return(mDNSNULL); } - if (ptr + sizeof(rdb->ipv6) > limit) return(mDNSNULL); - mDNSPlatformMemCopy(ptr, &rdb->ipv6, sizeof(rdb->ipv6)); - return(ptr + sizeof(rdb->ipv6)); - - case kDNSType_SRV: if (ptr + 7 > limit) return(mDNSNULL); - *ptr++ = (mDNSu8)(rdb->srv.priority >> 8); - *ptr++ = (mDNSu8)(rdb->srv.priority & 0xFF); - *ptr++ = (mDNSu8)(rdb->srv.weight >> 8); - *ptr++ = (mDNSu8)(rdb->srv.weight & 0xFF); - *ptr++ = rdb->srv.port.b[0]; - *ptr++ = rdb->srv.port.b[1]; - return(putDomainNameAsLabels(msg, ptr, limit, &rdb->srv.target)); - - case kDNSType_OPT: { - int len = 0; - const rdataOPT *opt; - const rdataOPT *const end = (const rdataOPT *)&rr->rdata->u.data[rr->rdlength]; - for (opt = &rr->rdata->u.opt[0]; opt < end; opt++) len += DNSOpt_Data_Space(opt); - if (ptr + len > limit) { LogMsg("ERROR: putOptRData - out of space"); return mDNSNULL; } - - for (opt = &rr->rdata->u.opt[0]; opt < end; opt++) - { - const int space = DNSOpt_Data_Space(opt); - ptr = putVal16(ptr, opt->opt); - ptr = putVal16(ptr, (mDNSu16)space - 4); - switch (opt->opt) - { - case kDNSOpt_LLQ: - ptr = putVal16(ptr, opt->u.llq.vers); - ptr = putVal16(ptr, opt->u.llq.llqOp); - ptr = putVal16(ptr, opt->u.llq.err); - mDNSPlatformMemCopy(ptr, opt->u.llq.id.b, 8); // 8-byte id - ptr += 8; - ptr = putVal32(ptr, opt->u.llq.llqlease); - break; - case kDNSOpt_Lease: - ptr = putVal32(ptr, opt->u.updatelease); - break; - case kDNSOpt_Owner: - *ptr++ = opt->u.owner.vers; - *ptr++ = opt->u.owner.seq; - mDNSPlatformMemCopy(ptr, opt->u.owner.HMAC.b, 6); // 6-byte Host identifier - ptr += 6; - if (space >= DNSOpt_OwnerData_ID_Wake_Space) - { - mDNSPlatformMemCopy(ptr, opt->u.owner.IMAC.b, 6); // 6-byte interface MAC - ptr += 6; - if (space > DNSOpt_OwnerData_ID_Wake_Space) - { - mDNSPlatformMemCopy(ptr, opt->u.owner.password.b, space - DNSOpt_OwnerData_ID_Wake_Space); - ptr += space - DNSOpt_OwnerData_ID_Wake_Space; - } - } - break; - } - } - return ptr; - } - - case kDNSType_NSEC: { - // For our simplified use of NSEC synthetic records: - // nextname is always the record's own name, - // the block number is always 0, - // the count byte is a value in the range 1-32, - // followed by the 1-32 data bytes - int i, j; - for (i=sizeof(rdataNSEC); i>0; i--) if (rdb->nsec.bitmap[i-1]) break; - ptr = putDomainNameAsLabels(msg, ptr, limit, rr->name); - if (!ptr) return(mDNSNULL); - if (i) // Only put a block if at least one type exists for this name - { - if (ptr + 2 + i > limit) return(mDNSNULL); - *ptr++ = 0; - *ptr++ = (mDNSu8)i; - for (j=0; j<i; j++) *ptr++ = rdb->nsec.bitmap[j]; - } - return ptr; - } - - default: debugf("putRData: Warning! Writing unknown resource type %d as raw data", rr->rrtype); - if (ptr + rr->rdlength > limit) return(mDNSNULL); - mDNSPlatformMemCopy(ptr, rdb->data, rr->rdlength); - return(ptr + rr->rdlength); - } - } - -#define IsUnicastUpdate(X) (!mDNSOpaque16IsZero((X)->h.id) && ((X)->h.flags.b[0] & kDNSFlag0_OP_Mask) == kDNSFlag0_OP_Update) - -mDNSexport mDNSu8 *PutResourceRecordTTLWithLimit(DNSMessage *const msg, mDNSu8 *ptr, mDNSu16 *count, ResourceRecord *rr, mDNSu32 ttl, const mDNSu8 *limit) - { - mDNSu8 *endofrdata; - mDNSu16 actualLength; - // When sending SRV to conventional DNS server (i.e. in DNS update requests) we should not do name compression on the rdata (RFC 2782) - const DNSMessage *const rdatacompressionbase = (IsUnicastUpdate(msg) && rr->rrtype == kDNSType_SRV) ? mDNSNULL : msg; - - if (rr->RecordType == kDNSRecordTypeUnregistered) - { - LogMsg("PutResourceRecord ERROR! Attempt to put kDNSRecordTypeUnregistered %##s (%s)", rr->name->c, DNSTypeName(rr->rrtype)); - return(ptr); - } - - if (!ptr) { LogMsg("PutResourceRecordTTLWithLimit ptr is null"); return(mDNSNULL); } - - ptr = putDomainNameAsLabels(msg, ptr, limit, rr->name); - if (!ptr || ptr + 10 >= limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL - ptr[0] = (mDNSu8)(rr->rrtype >> 8); - ptr[1] = (mDNSu8)(rr->rrtype & 0xFF); - ptr[2] = (mDNSu8)(rr->rrclass >> 8); - ptr[3] = (mDNSu8)(rr->rrclass & 0xFF); - ptr[4] = (mDNSu8)((ttl >> 24) & 0xFF); - ptr[5] = (mDNSu8)((ttl >> 16) & 0xFF); - ptr[6] = (mDNSu8)((ttl >> 8) & 0xFF); - ptr[7] = (mDNSu8)( ttl & 0xFF); - // ptr[8] and ptr[9] filled in *after* we find out how much space the rdata takes - - endofrdata = putRData(rdatacompressionbase, ptr+10, limit, rr); - if (!endofrdata) { verbosedebugf("Ran out of space in PutResourceRecord for %##s (%s)", rr->name->c, DNSTypeName(rr->rrtype)); return(mDNSNULL); } - - // Go back and fill in the actual number of data bytes we wrote - // (actualLength can be less than rdlength when domain name compression is used) - actualLength = (mDNSu16)(endofrdata - ptr - 10); - ptr[8] = (mDNSu8)(actualLength >> 8); - ptr[9] = (mDNSu8)(actualLength & 0xFF); - - if (count) (*count)++; - else LogMsg("PutResourceRecordTTL: ERROR: No target count to update for %##s (%s)", rr->name->c, DNSTypeName(rr->rrtype)); - return(endofrdata); - } - -mDNSlocal mDNSu8 *putEmptyResourceRecord(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, mDNSu16 *count, const AuthRecord *rr) - { - ptr = putDomainNameAsLabels(msg, ptr, limit, rr->resrec.name); - if (!ptr || ptr + 10 > limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL - ptr[0] = (mDNSu8)(rr->resrec.rrtype >> 8); // Put type - ptr[1] = (mDNSu8)(rr->resrec.rrtype & 0xFF); - ptr[2] = (mDNSu8)(rr->resrec.rrclass >> 8); // Put class - ptr[3] = (mDNSu8)(rr->resrec.rrclass & 0xFF); - ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // TTL is zero - ptr[8] = ptr[9] = 0; // RDATA length is zero - (*count)++; - return(ptr + 10); - } - -mDNSexport mDNSu8 *putQuestion(DNSMessage *const msg, mDNSu8 *ptr, const mDNSu8 *const limit, const domainname *const name, mDNSu16 rrtype, mDNSu16 rrclass) - { - ptr = putDomainNameAsLabels(msg, ptr, limit, name); - if (!ptr || ptr+4 >= limit) return(mDNSNULL); // If we're out-of-space, return mDNSNULL - ptr[0] = (mDNSu8)(rrtype >> 8); - ptr[1] = (mDNSu8)(rrtype & 0xFF); - ptr[2] = (mDNSu8)(rrclass >> 8); - ptr[3] = (mDNSu8)(rrclass & 0xFF); - msg->h.numQuestions++; - return(ptr+4); - } - -// for dynamic updates -mDNSexport mDNSu8 *putZone(DNSMessage *const msg, mDNSu8 *ptr, mDNSu8 *limit, const domainname *zone, mDNSOpaque16 zoneClass) - { - ptr = putDomainNameAsLabels(msg, ptr, limit, zone); - if (!ptr || ptr + 4 > limit) return mDNSNULL; // If we're out-of-space, return NULL - *ptr++ = (mDNSu8)(kDNSType_SOA >> 8); - *ptr++ = (mDNSu8)(kDNSType_SOA & 0xFF); - *ptr++ = zoneClass.b[0]; - *ptr++ = zoneClass.b[1]; - msg->h.mDNS_numZones++; - return ptr; - } - -// for dynamic updates -mDNSexport mDNSu8 *putPrereqNameNotInUse(const domainname *const name, DNSMessage *const msg, mDNSu8 *const ptr, mDNSu8 *const end) - { - AuthRecord prereq; - mDNS_SetupResourceRecord(&prereq, mDNSNULL, mDNSInterface_Any, kDNSQType_ANY, kStandardTTL, 0, AuthRecordAny, mDNSNULL, mDNSNULL); - AssignDomainName(&prereq.namestorage, name); - prereq.resrec.rrtype = kDNSQType_ANY; - prereq.resrec.rrclass = kDNSClass_NONE; - return putEmptyResourceRecord(msg, ptr, end, &msg->h.mDNS_numPrereqs, &prereq); - } - -// for dynamic updates -mDNSexport mDNSu8 *putDeletionRecord(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr) - { - // deletion: specify record w/ TTL 0, class NONE - const mDNSu16 origclass = rr->rrclass; - rr->rrclass = kDNSClass_NONE; - ptr = PutResourceRecordTTLJumbo(msg, ptr, &msg->h.mDNS_numUpdates, rr, 0); - rr->rrclass = origclass; - return ptr; - } - -// for dynamic updates -mDNSexport mDNSu8 *putDeletionRecordWithLimit(DNSMessage *msg, mDNSu8 *ptr, ResourceRecord *rr, mDNSu8 *limit) - { - // deletion: specify record w/ TTL 0, class NONE - const mDNSu16 origclass = rr->rrclass; - rr->rrclass = kDNSClass_NONE; - ptr = PutResourceRecordTTLWithLimit(msg, ptr, &msg->h.mDNS_numUpdates, rr, 0, limit); - rr->rrclass = origclass; - return ptr; - } - -mDNSexport mDNSu8 *putDeleteRRSetWithLimit(DNSMessage *msg, mDNSu8 *ptr, const domainname *name, mDNSu16 rrtype, mDNSu8 *limit) - { - mDNSu16 class = kDNSQClass_ANY; - - ptr = putDomainNameAsLabels(msg, ptr, limit, name); - if (!ptr || ptr + 10 >= limit) return mDNSNULL; // If we're out-of-space, return mDNSNULL - ptr[0] = (mDNSu8)(rrtype >> 8); - ptr[1] = (mDNSu8)(rrtype & 0xFF); - ptr[2] = (mDNSu8)(class >> 8); - ptr[3] = (mDNSu8)(class & 0xFF); - ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // zero ttl - ptr[8] = ptr[9] = 0; // zero rdlength/rdata - - msg->h.mDNS_numUpdates++; - return ptr + 10; - } - -// for dynamic updates -mDNSexport mDNSu8 *putDeleteAllRRSets(DNSMessage *msg, mDNSu8 *ptr, const domainname *name) - { - const mDNSu8 *limit = msg->data + AbsoluteMaxDNSMessageData; - mDNSu16 class = kDNSQClass_ANY; - mDNSu16 rrtype = kDNSQType_ANY; - - ptr = putDomainNameAsLabels(msg, ptr, limit, name); - if (!ptr || ptr + 10 >= limit) return mDNSNULL; // If we're out-of-space, return mDNSNULL - ptr[0] = (mDNSu8)(rrtype >> 8); - ptr[1] = (mDNSu8)(rrtype & 0xFF); - ptr[2] = (mDNSu8)(class >> 8); - ptr[3] = (mDNSu8)(class & 0xFF); - ptr[4] = ptr[5] = ptr[6] = ptr[7] = 0; // zero ttl - ptr[8] = ptr[9] = 0; // zero rdlength/rdata - - msg->h.mDNS_numUpdates++; - return ptr + 10; - } - -// for dynamic updates -mDNSexport mDNSu8 *putUpdateLease(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease) - { - AuthRecord rr; - mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); - rr.resrec.rrclass = NormalMaxDNSMessageData; - rr.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record - rr.resrec.rdestimate = sizeof(rdataOPT); - rr.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease; - rr.resrec.rdata->u.opt[0].u.updatelease = lease; - end = PutResourceRecordTTLJumbo(msg, end, &msg->h.numAdditionals, &rr.resrec, 0); - if (!end) { LogMsg("ERROR: putUpdateLease - PutResourceRecordTTL"); return mDNSNULL; } - return end; - } - -// for dynamic updates -mDNSexport mDNSu8 *putUpdateLeaseWithLimit(DNSMessage *msg, mDNSu8 *end, mDNSu32 lease, mDNSu8 *limit) - { - AuthRecord rr; - mDNS_SetupResourceRecord(&rr, mDNSNULL, mDNSInterface_Any, kDNSType_OPT, kStandardTTL, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL); - rr.resrec.rrclass = NormalMaxDNSMessageData; - rr.resrec.rdlength = sizeof(rdataOPT); // One option in this OPT record - rr.resrec.rdestimate = sizeof(rdataOPT); - rr.resrec.rdata->u.opt[0].opt = kDNSOpt_Lease; - rr.resrec.rdata->u.opt[0].u.updatelease = lease; - end = PutResourceRecordTTLWithLimit(msg, end, &msg->h.numAdditionals, &rr.resrec, 0, limit); - if (!end) { LogMsg("ERROR: putUpdateLease - PutResourceRecordTTLWithLimit"); return mDNSNULL; } - return end; - } - -mDNSexport mDNSu8 *putHINFO(const mDNS *const m, DNSMessage *const msg, mDNSu8 *end, DomainAuthInfo *authInfo, mDNSu8 *limit) - { - if (authInfo && authInfo->AutoTunnel) - { - AuthRecord hinfo; - mDNSu8 *h = hinfo.rdatastorage.u.data; - mDNSu16 len = 2 + m->HIHardware.c[0] + m->HISoftware.c[0]; - mDNSu8 *newptr; - mDNS_SetupResourceRecord(&hinfo, mDNSNULL, mDNSInterface_Any, kDNSType_HINFO, 0, kDNSRecordTypeUnique, AuthRecordAny, mDNSNULL, mDNSNULL); - AppendDomainLabel(&hinfo.namestorage, &m->hostlabel); - AppendDomainName (&hinfo.namestorage, &authInfo->domain); - hinfo.resrec.rroriginalttl = 0; - mDNSPlatformMemCopy(h, &m->HIHardware, 1 + (mDNSu32)m->HIHardware.c[0]); - h += 1 + (int)h[0]; - mDNSPlatformMemCopy(h, &m->HISoftware, 1 + (mDNSu32)m->HISoftware.c[0]); - hinfo.resrec.rdlength = len; - hinfo.resrec.rdestimate = len; - newptr = PutResourceRecordTTLWithLimit(msg, end, &msg->h.numAdditionals, &hinfo.resrec, 0, limit); - return newptr; - } - else - return end; - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - DNS Message Parsing Functions -#endif - -mDNSexport mDNSu32 DomainNameHashValue(const domainname *const name) - { - mDNSu32 sum = 0; - const mDNSu8 *c; - - for (c = name->c; c[0] != 0 && c[1] != 0; c += 2) - { - sum += ((mDNSIsUpperCase(c[0]) ? c[0] + 'a' - 'A' : c[0]) << 8) | - (mDNSIsUpperCase(c[1]) ? c[1] + 'a' - 'A' : c[1]); - sum = (sum<<3) | (sum>>29); - } - if (c[0]) sum += ((mDNSIsUpperCase(c[0]) ? c[0] + 'a' - 'A' : c[0]) << 8); - return(sum); - } - -mDNSexport void SetNewRData(ResourceRecord *const rr, RData *NewRData, mDNSu16 rdlength) - { - domainname *target; - if (NewRData) - { - rr->rdata = NewRData; - rr->rdlength = rdlength; - } - // Must not try to get target pointer until after updating rr->rdata - target = GetRRDomainNameTarget(rr); - rr->rdlength = GetRDLength(rr, mDNSfalse); - rr->rdestimate = GetRDLength(rr, mDNStrue); - rr->rdatahash = target ? DomainNameHashValue(target) : RDataHashValue(rr); - } - -mDNSexport const mDNSu8 *skipDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end) - { - mDNSu16 total = 0; - - if (ptr < (mDNSu8*)msg || ptr >= end) - { debugf("skipDomainName: Illegal ptr not within packet boundaries"); return(mDNSNULL); } - - while (1) // Read sequence of labels - { - const mDNSu8 len = *ptr++; // Read length of this label - if (len == 0) return(ptr); // If length is zero, that means this name is complete - switch (len & 0xC0) - { - case 0x00: if (ptr + len >= end) // Remember: expect at least one more byte for the root label - { debugf("skipDomainName: Malformed domain name (overruns packet end)"); return(mDNSNULL); } - if (total + 1 + len >= MAX_DOMAIN_NAME) // Remember: expect at least one more byte for the root label - { debugf("skipDomainName: Malformed domain name (more than 256 characters)"); return(mDNSNULL); } - ptr += len; - total += 1 + len; - break; - - case 0x40: debugf("skipDomainName: Extended EDNS0 label types 0x%X not supported", len); return(mDNSNULL); - case 0x80: debugf("skipDomainName: Illegal label length 0x%X", len); return(mDNSNULL); - case 0xC0: return(ptr+1); - } - } - } - -// Routine to fetch an FQDN from the DNS message, following compression pointers if necessary. -mDNSexport const mDNSu8 *getDomainName(const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, - domainname *const name) - { - const mDNSu8 *nextbyte = mDNSNULL; // Record where we got to before we started following pointers - mDNSu8 *np = name->c; // Name pointer - const mDNSu8 *const limit = np + MAX_DOMAIN_NAME; // Limit so we don't overrun buffer - - if (ptr < (mDNSu8*)msg || ptr >= end) - { debugf("getDomainName: Illegal ptr not within packet boundaries"); return(mDNSNULL); } - - *np = 0; // Tentatively place the root label here (may be overwritten if we have more labels) - - while (1) // Read sequence of labels - { - const mDNSu8 len = *ptr++; // Read length of this label - if (len == 0) break; // If length is zero, that means this name is complete - switch (len & 0xC0) - { - int i; - mDNSu16 offset; - - case 0x00: if (ptr + len >= end) // Remember: expect at least one more byte for the root label - { debugf("getDomainName: Malformed domain name (overruns packet end)"); return(mDNSNULL); } - if (np + 1 + len >= limit) // Remember: expect at least one more byte for the root label - { debugf("getDomainName: Malformed domain name (more than 256 characters)"); return(mDNSNULL); } - *np++ = len; - for (i=0; i<len; i++) *np++ = *ptr++; - *np = 0; // Tentatively place the root label here (may be overwritten if we have more labels) - break; - - case 0x40: debugf("getDomainName: Extended EDNS0 label types 0x%X not supported in name %##s", len, name->c); - return(mDNSNULL); - - case 0x80: debugf("getDomainName: Illegal label length 0x%X in domain name %##s", len, name->c); return(mDNSNULL); - - case 0xC0: offset = (mDNSu16)((((mDNSu16)(len & 0x3F)) << 8) | *ptr++); - if (!nextbyte) nextbyte = ptr; // Record where we got to before we started following pointers - ptr = (mDNSu8 *)msg + offset; - if (ptr < (mDNSu8*)msg || ptr >= end) - { debugf("getDomainName: Illegal compression pointer not within packet boundaries"); return(mDNSNULL); } - if (*ptr & 0xC0) - { debugf("getDomainName: Compression pointer must point to real label"); return(mDNSNULL); } - break; - } - } - - if (nextbyte) return(nextbyte); - else return(ptr); - } - -mDNSexport const mDNSu8 *skipResourceRecord(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end) - { - mDNSu16 pktrdlength; - - ptr = skipDomainName(msg, ptr, end); - if (!ptr) { debugf("skipResourceRecord: Malformed RR name"); return(mDNSNULL); } - - if (ptr + 10 > end) { debugf("skipResourceRecord: Malformed RR -- no type/class/ttl/len!"); return(mDNSNULL); } - pktrdlength = (mDNSu16)((mDNSu16)ptr[8] << 8 | ptr[9]); - ptr += 10; - if (ptr + pktrdlength > end) { debugf("skipResourceRecord: RDATA exceeds end of packet"); return(mDNSNULL); } - - return(ptr + pktrdlength); - } - -mDNSexport const mDNSu8 *GetLargeResourceRecord(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *ptr, - const mDNSu8 *end, const mDNSInterfaceID InterfaceID, mDNSu8 RecordType, LargeCacheRecord *const largecr) - { - CacheRecord *const rr = &largecr->r; - RDataBody2 *const rdb = (RDataBody2 *)rr->smallrdatastorage.data; - mDNSu16 pktrdlength; - - if (largecr == &m->rec && m->rec.r.resrec.RecordType) - { - LogMsg("GetLargeResourceRecord: m->rec appears to be already in use for %s", CRDisplayString(m, &m->rec.r)); -#if ForceAlerts - *(long*)0 = 0; -#endif - } - - rr->next = mDNSNULL; - rr->resrec.name = &largecr->namestorage; - - rr->NextInKAList = mDNSNULL; - rr->TimeRcvd = m ? m->timenow : 0; - rr->DelayDelivery = 0; - rr->NextRequiredQuery = m ? m->timenow : 0; // Will be updated to the real value when we call SetNextCacheCheckTimeForRecord() - rr->LastUsed = m ? m->timenow : 0; - rr->CRActiveQuestion = mDNSNULL; - rr->UnansweredQueries = 0; - rr->LastUnansweredTime= 0; -#if ENABLE_MULTI_PACKET_QUERY_SNOOPING - rr->MPUnansweredQ = 0; - rr->MPLastUnansweredQT= 0; - rr->MPUnansweredKA = 0; - rr->MPExpectingKA = mDNSfalse; -#endif - rr->NextInCFList = mDNSNULL; - - rr->resrec.InterfaceID = InterfaceID; - rr->resrec.rDNSServer = mDNSNULL; - - ptr = getDomainName(msg, ptr, end, &largecr->namestorage); // Will bail out correctly if ptr is NULL - if (!ptr) { debugf("GetLargeResourceRecord: Malformed RR name"); return(mDNSNULL); } - rr->resrec.namehash = DomainNameHashValue(rr->resrec.name); - - if (ptr + 10 > end) { debugf("GetLargeResourceRecord: Malformed RR -- no type/class/ttl/len!"); return(mDNSNULL); } - - rr->resrec.rrtype = (mDNSu16) ((mDNSu16)ptr[0] << 8 | ptr[1]); - rr->resrec.rrclass = (mDNSu16)(((mDNSu16)ptr[2] << 8 | ptr[3]) & kDNSClass_Mask); - rr->resrec.rroriginalttl = (mDNSu32) ((mDNSu32)ptr[4] << 24 | (mDNSu32)ptr[5] << 16 | (mDNSu32)ptr[6] << 8 | ptr[7]); - if (rr->resrec.rroriginalttl > 0x70000000UL / mDNSPlatformOneSecond && (mDNSs32)rr->resrec.rroriginalttl != -1) - rr->resrec.rroriginalttl = 0x70000000UL / mDNSPlatformOneSecond; - // Note: We don't have to adjust m->NextCacheCheck here -- this is just getting a record into memory for - // us to look at. If we decide to copy it into the cache, then we'll update m->NextCacheCheck accordingly. - pktrdlength = (mDNSu16)((mDNSu16)ptr[8] << 8 | ptr[9]); - - // If mDNS record has cache-flush bit set, we mark it unique - // For uDNS records, all are implicitly deemed unique (a single DNS server is always - // authoritative for the entire RRSet), unless this is a truncated response - if (ptr[2] & (kDNSClass_UniqueRRSet >> 8) || (!InterfaceID && !(msg->h.flags.b[0] & kDNSFlag0_TC))) - RecordType |= kDNSRecordTypePacketUniqueMask; - ptr += 10; - if (ptr + pktrdlength > end) { debugf("GetLargeResourceRecord: RDATA exceeds end of packet"); return(mDNSNULL); } - end = ptr + pktrdlength; // Adjust end to indicate the end of the rdata for this resource record - - rr->resrec.rdata = (RData*)&rr->smallrdatastorage; - rr->resrec.rdata->MaxRDLength = MaximumRDSize; - - if (!RecordType) LogMsg("GetLargeResourceRecord: No RecordType for %##s", rr->resrec.name->c); - - // IMPORTANT: Any record type we understand and unpack into a structure containing domainnames needs to have corresponding - // cases in SameRDataBody() and RDataHashValue() to do a semantic comparison (or checksum) of the structure instead of a blind - // bitwise memory compare (or sum). This is because a domainname is a fixed size structure holding variable-length data. - // Any bytes past the logical end of the name are undefined, and a blind bitwise memory compare may indicate that - // two domainnames are different when semantically they are the same name and it's only the unused bytes that differ. - if (rr->resrec.rrclass == kDNSQClass_ANY && pktrdlength == 0) // Used in update packets to mean "Delete An RRset" (RFC 2136) - rr->resrec.rdlength = 0; - else switch (rr->resrec.rrtype) - { - case kDNSType_A: if (pktrdlength != sizeof(mDNSv4Addr)) goto fail; - rdb->ipv4.b[0] = ptr[0]; - rdb->ipv4.b[1] = ptr[1]; - rdb->ipv4.b[2] = ptr[2]; - rdb->ipv4.b[3] = ptr[3]; - break; - - case kDNSType_NS: - case kDNSType_CNAME: - case kDNSType_PTR: - case kDNSType_DNAME:ptr = getDomainName(msg, ptr, end, &rdb->name); - if (ptr != end) { debugf("GetLargeResourceRecord: Malformed CNAME/PTR RDATA name"); goto fail; } - //debugf("%##s PTR %##s rdlen %d", rr->resrec.name.c, rdb->name.c, pktrdlength); - break; - - case kDNSType_SOA: ptr = getDomainName(msg, ptr, end, &rdb->soa.mname); - if (!ptr) { debugf("GetLargeResourceRecord: Malformed SOA RDATA mname"); goto fail; } - ptr = getDomainName(msg, ptr, end, &rdb->soa.rname); - if (!ptr) { debugf("GetLargeResourceRecord: Malformed SOA RDATA rname"); goto fail; } - if (ptr + 0x14 != end) { debugf("GetLargeResourceRecord: Malformed SOA RDATA"); goto fail; } - rdb->soa.serial = (mDNSs32) ((mDNSs32)ptr[0x00] << 24 | (mDNSs32)ptr[0x01] << 16 | (mDNSs32)ptr[0x02] << 8 | ptr[0x03]); - rdb->soa.refresh = (mDNSu32) ((mDNSu32)ptr[0x04] << 24 | (mDNSu32)ptr[0x05] << 16 | (mDNSu32)ptr[0x06] << 8 | ptr[0x07]); - rdb->soa.retry = (mDNSu32) ((mDNSu32)ptr[0x08] << 24 | (mDNSu32)ptr[0x09] << 16 | (mDNSu32)ptr[0x0A] << 8 | ptr[0x0B]); - rdb->soa.expire = (mDNSu32) ((mDNSu32)ptr[0x0C] << 24 | (mDNSu32)ptr[0x0D] << 16 | (mDNSu32)ptr[0x0E] << 8 | ptr[0x0F]); - rdb->soa.min = (mDNSu32) ((mDNSu32)ptr[0x10] << 24 | (mDNSu32)ptr[0x11] << 16 | (mDNSu32)ptr[0x12] << 8 | ptr[0x13]); - break; - - case kDNSType_NULL: - case kDNSType_HINFO: - case kDNSType_TSIG: - case kDNSType_TXT: - case kDNSType_X25: - case kDNSType_ISDN: - case kDNSType_LOC: - case kDNSType_DHCID:if (pktrdlength > rr->resrec.rdata->MaxRDLength) - { - debugf("GetLargeResourceRecord: %s rdata size (%d) exceeds storage (%d)", - DNSTypeName(rr->resrec.rrtype), pktrdlength, rr->resrec.rdata->MaxRDLength); - goto fail; - } - rr->resrec.rdlength = pktrdlength; - mDNSPlatformMemCopy(rdb->data, ptr, pktrdlength); - break; - - case kDNSType_MX: - case kDNSType_AFSDB: - case kDNSType_RT: - case kDNSType_KX: if (pktrdlength < 3) goto fail; // Preference + domainname - rdb->mx.preference = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); - ptr = getDomainName(msg, ptr+2, end, &rdb->mx.exchange); - if (ptr != end) { debugf("GetLargeResourceRecord: Malformed MX name"); goto fail; } - //debugf("%##s SRV %##s rdlen %d", rr->resrec.name.c, rdb->srv.target.c, pktrdlength); - break; - - case kDNSType_RP: ptr = getDomainName(msg, ptr, end, &rdb->rp.mbox); // Domainname + domainname - if (!ptr) { debugf("GetLargeResourceRecord: Malformed RP mbox"); goto fail; } - ptr = getDomainName(msg, ptr, end, &rdb->rp.txt); - if (ptr != end) { debugf("GetLargeResourceRecord: Malformed RP txt"); goto fail; } - break; - - case kDNSType_PX: if (pktrdlength < 4) goto fail; // Preference + domainname + domainname - rdb->px.preference = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); - ptr = getDomainName(msg, ptr, end, &rdb->px.map822); - if (!ptr) { debugf("GetLargeResourceRecord: Malformed PX map822"); goto fail; } - ptr = getDomainName(msg, ptr, end, &rdb->px.mapx400); - if (ptr != end) { debugf("GetLargeResourceRecord: Malformed PX mapx400"); goto fail; } - break; - - case kDNSType_AAAA: if (pktrdlength != sizeof(mDNSv6Addr)) goto fail; - mDNSPlatformMemCopy(&rdb->ipv6, ptr, sizeof(rdb->ipv6)); - break; - - case kDNSType_SRV: if (pktrdlength < 7) goto fail; // Priority + weight + port + domainname - rdb->srv.priority = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); - rdb->srv.weight = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); - rdb->srv.port.b[0] = ptr[4]; - rdb->srv.port.b[1] = ptr[5]; - ptr = getDomainName(msg, ptr+6, end, &rdb->srv.target); - if (ptr != end) { debugf("GetLargeResourceRecord: Malformed SRV RDATA name"); goto fail; } - //debugf("%##s SRV %##s rdlen %d", rr->resrec.name.c, rdb->srv.target.c, pktrdlength); - break; - - case kDNSType_OPT: { - rdataOPT *opt = rr->resrec.rdata->u.opt; - rr->resrec.rdlength = 0; - while (ptr < end && (mDNSu8 *)(opt+1) < &rr->resrec.rdata->u.data[MaximumRDSize]) - { - const rdataOPT *const currentopt = opt; - if (ptr + 4 > end) { LogInfo("GetLargeResourceRecord: OPT RDATA ptr + 4 > end"); goto fail; } - opt->opt = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); - opt->optlen = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); - ptr += 4; - if (ptr + opt->optlen > end) { LogInfo("GetLargeResourceRecord: ptr + opt->optlen > end"); goto fail; } - switch (opt->opt) - { - case kDNSOpt_LLQ: - if (opt->optlen == DNSOpt_LLQData_Space - 4) - { - opt->u.llq.vers = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); - opt->u.llq.llqOp = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); - opt->u.llq.err = (mDNSu16)((mDNSu16)ptr[4] << 8 | ptr[5]); - mDNSPlatformMemCopy(opt->u.llq.id.b, ptr+6, 8); - opt->u.llq.llqlease = (mDNSu32) ((mDNSu32)ptr[14] << 24 | (mDNSu32)ptr[15] << 16 | (mDNSu32)ptr[16] << 8 | ptr[17]); - if (opt->u.llq.llqlease > 0x70000000UL / mDNSPlatformOneSecond) - opt->u.llq.llqlease = 0x70000000UL / mDNSPlatformOneSecond; - opt++; - } - break; - case kDNSOpt_Lease: - if (opt->optlen == DNSOpt_LeaseData_Space - 4) - { - opt->u.updatelease = (mDNSu32) ((mDNSu32)ptr[0] << 24 | (mDNSu32)ptr[1] << 16 | (mDNSu32)ptr[2] << 8 | ptr[3]); - if (opt->u.updatelease > 0x70000000UL / mDNSPlatformOneSecond) - opt->u.updatelease = 0x70000000UL / mDNSPlatformOneSecond; - opt++; - } - break; - case kDNSOpt_Owner: - if (ValidOwnerLength(opt->optlen)) - { - opt->u.owner.vers = ptr[0]; - opt->u.owner.seq = ptr[1]; - mDNSPlatformMemCopy(opt->u.owner.HMAC.b, ptr+2, 6); // 6-byte MAC address - mDNSPlatformMemCopy(opt->u.owner.IMAC.b, ptr+2, 6); // 6-byte MAC address - opt->u.owner.password = zeroEthAddr; - if (opt->optlen >= DNSOpt_OwnerData_ID_Wake_Space-4) - { - mDNSPlatformMemCopy(opt->u.owner.IMAC.b, ptr+8, 6); // 6-byte MAC address - // This mDNSPlatformMemCopy is safe because the ValidOwnerLength(opt->optlen) check above - // ensures that opt->optlen is no more than DNSOpt_OwnerData_ID_Wake_PW6_Space - 4 - if (opt->optlen > DNSOpt_OwnerData_ID_Wake_Space-4) - mDNSPlatformMemCopy(opt->u.owner.password.b, ptr+14, opt->optlen - (DNSOpt_OwnerData_ID_Wake_Space-4)); - } - opt++; - } - break; - } - ptr += currentopt->optlen; - } - rr->resrec.rdlength = (mDNSu16)((mDNSu8*)opt - rr->resrec.rdata->u.data); - if (ptr != end) { LogInfo("GetLargeResourceRecord: Malformed OptRdata"); goto fail; } - break; - } - - case kDNSType_NSEC: { - unsigned int i, j; - domainname d; - ptr = getDomainName(msg, ptr, end, &d); // Ignored for our simplified use of NSEC synthetic records - if (!ptr) { LogInfo("GetLargeResourceRecord: Malformed NSEC nextname"); goto fail; } - mDNSPlatformMemZero(rdb->nsec.bitmap, sizeof(rdb->nsec.bitmap)); - if (ptr < end) - { - if (*ptr++ != 0) { debugf("GetLargeResourceRecord: We only handle block zero NSECs"); goto fail; } - i = *ptr++; - if (i > sizeof(rdataNSEC)) { debugf("GetLargeResourceRecord: invalid block length %d", i); goto fail; } - for (j=0; j<i; j++) rdb->nsec.bitmap[j] = *ptr++; - } - if (ptr != end) { debugf("GetLargeResourceRecord: Malformed NSEC"); goto fail; } - break; - } - - default: if (pktrdlength > rr->resrec.rdata->MaxRDLength) - { - debugf("GetLargeResourceRecord: rdata %d (%s) size (%d) exceeds storage (%d)", - rr->resrec.rrtype, DNSTypeName(rr->resrec.rrtype), pktrdlength, rr->resrec.rdata->MaxRDLength); - goto fail; - } - debugf("GetLargeResourceRecord: Warning! Reading resource type %d (%s) as opaque data", - rr->resrec.rrtype, DNSTypeName(rr->resrec.rrtype)); - // Note: Just because we don't understand the record type, that doesn't - // mean we fail. The DNS protocol specifies rdlength, so we can - // safely skip over unknown records and ignore them. - // We also grab a binary copy of the rdata anyway, since the caller - // might know how to interpret it even if we don't. - rr->resrec.rdlength = pktrdlength; - mDNSPlatformMemCopy(rdb->data, ptr, pktrdlength); - break; - } - - SetNewRData(&rr->resrec, mDNSNULL, 0); // Sets rdlength, rdestimate, rdatahash for us - - // Success! Now fill in RecordType to show this record contains valid data - rr->resrec.RecordType = RecordType; - return(end); - -fail: - // If we were unable to parse the rdata in this record, we indicate that by - // returing a 'kDNSRecordTypePacketNegative' record with rdlength set to zero - rr->resrec.RecordType = kDNSRecordTypePacketNegative; - rr->resrec.rdlength = 0; - rr->resrec.rdestimate = 0; - rr->resrec.rdatahash = 0; - return(end); - } - -mDNSexport const mDNSu8 *skipQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end) - { - ptr = skipDomainName(msg, ptr, end); - if (!ptr) { debugf("skipQuestion: Malformed domain name in DNS question section"); return(mDNSNULL); } - if (ptr+4 > end) { debugf("skipQuestion: Malformed DNS question section -- no query type and class!"); return(mDNSNULL); } - return(ptr+4); - } - -mDNSexport const mDNSu8 *getQuestion(const DNSMessage *msg, const mDNSu8 *ptr, const mDNSu8 *end, const mDNSInterfaceID InterfaceID, - DNSQuestion *question) - { - mDNSPlatformMemZero(question, sizeof(*question)); - question->InterfaceID = InterfaceID; - if (!InterfaceID) question->TargetQID = onesID; // In DNSQuestions we use TargetQID as the indicator of whether it's unicast or multicast - ptr = getDomainName(msg, ptr, end, &question->qname); - if (!ptr) { debugf("Malformed domain name in DNS question section"); return(mDNSNULL); } - if (ptr+4 > end) { debugf("Malformed DNS question section -- no query type and class!"); return(mDNSNULL); } - - question->qnamehash = DomainNameHashValue(&question->qname); - question->qtype = (mDNSu16)((mDNSu16)ptr[0] << 8 | ptr[1]); // Get type - question->qclass = (mDNSu16)((mDNSu16)ptr[2] << 8 | ptr[3]); // and class - return(ptr+4); - } - -mDNSexport const mDNSu8 *LocateAnswers(const DNSMessage *const msg, const mDNSu8 *const end) - { - int i; - const mDNSu8 *ptr = msg->data; - for (i = 0; i < msg->h.numQuestions && ptr; i++) ptr = skipQuestion(msg, ptr, end); - return(ptr); - } - -mDNSexport const mDNSu8 *LocateAuthorities(const DNSMessage *const msg, const mDNSu8 *const end) - { - int i; - const mDNSu8 *ptr = LocateAnswers(msg, end); - for (i = 0; i < msg->h.numAnswers && ptr; i++) ptr = skipResourceRecord(msg, ptr, end); - return(ptr); - } - -mDNSexport const mDNSu8 *LocateAdditionals(const DNSMessage *const msg, const mDNSu8 *const end) - { - int i; - const mDNSu8 *ptr = LocateAuthorities(msg, end); - for (i = 0; i < msg->h.numAuthorities; i++) ptr = skipResourceRecord(msg, ptr, end); - return (ptr); - } - -mDNSexport const mDNSu8 *LocateOptRR(const DNSMessage *const msg, const mDNSu8 *const end, int minsize) - { - int i; - const mDNSu8 *ptr = LocateAdditionals(msg, end); - - // Locate the OPT record. - // According to RFC 2671, "One OPT pseudo-RR can be added to the additional data section of either a request or a response." - // This implies that there may be *at most* one OPT record per DNS message, in the Additional Section, - // but not necessarily the *last* entry in the Additional Section. - for (i = 0; ptr && i < msg->h.numAdditionals; i++) - { - if (ptr + DNSOpt_Header_Space + minsize <= end && // Make sure we have 11+minsize bytes of data - ptr[0] == 0 && // Name must be root label - ptr[1] == (kDNSType_OPT >> 8 ) && // rrtype OPT - ptr[2] == (kDNSType_OPT & 0xFF) && - ((mDNSu16)ptr[9] << 8 | (mDNSu16)ptr[10]) >= (mDNSu16)minsize) - return(ptr); - else - ptr = skipResourceRecord(msg, ptr, end); - } - return(mDNSNULL); - } - -// On success, GetLLQOptData returns pointer to storage within shared "m->rec"; -// it is caller's responsibilty to clear m->rec.r.resrec.RecordType after use -// Note: An OPT RDataBody actually contains one or more variable-length rdataOPT objects packed together -// The code that currently calls this assumes there's only one, instead of iterating through the set -mDNSexport const rdataOPT *GetLLQOptData(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end) - { - const mDNSu8 *ptr = LocateOptRR(msg, end, DNSOpt_LLQData_Space); - if (ptr) - { - ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); - if (ptr && m->rec.r.resrec.RecordType != kDNSRecordTypePacketNegative) return(&m->rec.r.resrec.rdata->u.opt[0]); - } - return(mDNSNULL); - } - -// Get the lease life of records in a dynamic update -// returns 0 on error or if no lease present -mDNSexport mDNSu32 GetPktLease(mDNS *m, DNSMessage *msg, const mDNSu8 *end) - { - mDNSu32 result = 0; - const mDNSu8 *ptr = LocateOptRR(msg, end, DNSOpt_LeaseData_Space); - if (ptr) ptr = GetLargeResourceRecord(m, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &m->rec); - if (ptr && m->rec.r.resrec.rdlength >= DNSOpt_LeaseData_Space && m->rec.r.resrec.rdata->u.opt[0].opt == kDNSOpt_Lease) - result = m->rec.r.resrec.rdata->u.opt[0].u.updatelease; - m->rec.r.resrec.RecordType = 0; // Clear RecordType to show we're not still using it - return(result); - } - -mDNSlocal const mDNSu8 *DumpRecords(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *ptr, const mDNSu8 *const end, int count, char *label) - { - int i; - LogMsg("%2d %s", count, label); - for (i = 0; i < count && ptr; i++) - { - // This puts a LargeCacheRecord on the stack instead of using the shared m->rec storage, - // but since it's only used for debugging (and probably only on OS X, not on - // embedded systems) putting a 9kB object on the stack isn't a big problem. - LargeCacheRecord largecr; - ptr = GetLargeResourceRecord(m, msg, ptr, end, mDNSInterface_Any, kDNSRecordTypePacketAns, &largecr); - if (ptr) LogMsg("%2d TTL%8d %s", i, largecr.r.resrec.rroriginalttl, CRDisplayString(m, &largecr.r)); - } - if (!ptr) LogMsg("ERROR: Premature end of packet data"); - return(ptr); - } - -#define DNS_OP_Name(X) ( \ - (X) == kDNSFlag0_OP_StdQuery ? "" : \ - (X) == kDNSFlag0_OP_Iquery ? "Iquery " : \ - (X) == kDNSFlag0_OP_Status ? "Status " : \ - (X) == kDNSFlag0_OP_Unused3 ? "Unused3 " : \ - (X) == kDNSFlag0_OP_Notify ? "Notify " : \ - (X) == kDNSFlag0_OP_Update ? "Update " : "?? " ) - -#define DNS_RC_Name(X) ( \ - (X) == kDNSFlag1_RC_NoErr ? "NoErr" : \ - (X) == kDNSFlag1_RC_FormErr ? "FormErr" : \ - (X) == kDNSFlag1_RC_ServFail ? "ServFail" : \ - (X) == kDNSFlag1_RC_NXDomain ? "NXDomain" : \ - (X) == kDNSFlag1_RC_NotImpl ? "NotImpl" : \ - (X) == kDNSFlag1_RC_Refused ? "Refused" : \ - (X) == kDNSFlag1_RC_YXDomain ? "YXDomain" : \ - (X) == kDNSFlag1_RC_YXRRSet ? "YXRRSet" : \ - (X) == kDNSFlag1_RC_NXRRSet ? "NXRRSet" : \ - (X) == kDNSFlag1_RC_NotAuth ? "NotAuth" : \ - (X) == kDNSFlag1_RC_NotZone ? "NotZone" : "??" ) - -// Note: DumpPacket expects the packet header fields in host byte order, not network byte order -mDNSexport void DumpPacket(mDNS *const m, mStatus status, mDNSBool sent, char *transport, - const mDNSAddr *srcaddr, mDNSIPPort srcport, - const mDNSAddr *dstaddr, mDNSIPPort dstport, const DNSMessage *const msg, const mDNSu8 *const end) - { - mDNSBool IsUpdate = ((msg->h.flags.b[0] & kDNSFlag0_OP_Mask) == kDNSFlag0_OP_Update); - const mDNSu8 *ptr = msg->data; - int i; - DNSQuestion q; - char tbuffer[64], sbuffer[64], dbuffer[64] = ""; - if (!status) tbuffer[mDNS_snprintf(tbuffer, sizeof(tbuffer), sent ? "Sent" : "Received" )] = 0; - else tbuffer[mDNS_snprintf(tbuffer, sizeof(tbuffer), "ERROR %d %sing", status, sent ? "Send" : "Receiv")] = 0; - if (sent) sbuffer[mDNS_snprintf(sbuffer, sizeof(sbuffer), "port " )] = 0; - else sbuffer[mDNS_snprintf(sbuffer, sizeof(sbuffer), "%#a:", srcaddr)] = 0; - if (dstaddr || !mDNSIPPortIsZero(dstport)) - dbuffer[mDNS_snprintf(dbuffer, sizeof(dbuffer), " to %#a:%d", dstaddr, mDNSVal16(dstport))] = 0; - - LogMsg("-- %s %s DNS %s%s (flags %02X%02X) RCODE: %s (%d) %s%s%s%s%s%sID: %d %d bytes from %s%d%s%s --", - tbuffer, transport, - DNS_OP_Name(msg->h.flags.b[0] & kDNSFlag0_OP_Mask), - msg->h.flags.b[0] & kDNSFlag0_QR_Response ? "Response" : "Query", - msg->h.flags.b[0], msg->h.flags.b[1], - DNS_RC_Name(msg->h.flags.b[1] & kDNSFlag1_RC_Mask), - msg->h.flags.b[1] & kDNSFlag1_RC_Mask, - msg->h.flags.b[0] & kDNSFlag0_AA ? "AA " : "", - msg->h.flags.b[0] & kDNSFlag0_TC ? "TC " : "", - msg->h.flags.b[0] & kDNSFlag0_RD ? "RD " : "", - msg->h.flags.b[1] & kDNSFlag1_RA ? "RA " : "", - msg->h.flags.b[1] & kDNSFlag1_AD ? "AD " : "", - msg->h.flags.b[1] & kDNSFlag1_CD ? "CD " : "", - mDNSVal16(msg->h.id), - end - msg->data, - sbuffer, mDNSVal16(srcport), dbuffer, - (msg->h.flags.b[0] & kDNSFlag0_TC) ? " (truncated)" : "" - ); - - LogMsg("%2d %s", msg->h.numQuestions, IsUpdate ? "Zone" : "Questions"); - for (i = 0; i < msg->h.numQuestions && ptr; i++) - { - ptr = getQuestion(msg, ptr, end, mDNSInterface_Any, &q); - if (ptr) LogMsg("%2d %##s %s", i, q.qname.c, DNSTypeName(q.qtype)); - } - ptr = DumpRecords(m, msg, ptr, end, msg->h.numAnswers, IsUpdate ? "Prerequisites" : "Answers"); - ptr = DumpRecords(m, msg, ptr, end, msg->h.numAuthorities, IsUpdate ? "Updates" : "Authorities"); - ptr = DumpRecords(m, msg, ptr, end, msg->h.numAdditionals, "Additionals"); - LogMsg("--------------"); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - Packet Sending Functions -#endif - -// Stub definition of TCPSocket_struct so we can access flags field. (Rest of TCPSocket_struct is platform-dependent.) -struct TCPSocket_struct { TCPSocketFlags flags; /* ... */ }; - -struct UDPSocket_struct - { - mDNSIPPort port; // MUST BE FIRST FIELD -- mDNSCoreReceive expects every UDPSocket_struct to begin with mDNSIPPort port - }; - -// Note: When we sign a DNS message using DNSDigest_SignMessage(), the current real-time clock value is used, which -// is why we generally defer signing until we send the message, to ensure the signature is as fresh as possible. -mDNSexport mStatus mDNSSendDNSMessage(mDNS *const m, DNSMessage *const msg, mDNSu8 *end, - mDNSInterfaceID InterfaceID, UDPSocket *src, const mDNSAddr *dst, mDNSIPPort dstport, TCPSocket *sock, DomainAuthInfo *authInfo) - { - mStatus status = mStatus_NoError; - const mDNSu16 numAdditionals = msg->h.numAdditionals; - mDNSu8 *newend; - mDNSu8 *limit = msg->data + AbsoluteMaxDNSMessageData; - - // Zero-length message data is okay (e.g. for a DNS Update ack, where all we need is an ID and an error code - if (end < msg->data || end - msg->data > AbsoluteMaxDNSMessageData) - { - LogMsg("mDNSSendDNSMessage: invalid message %p %p %d", msg->data, end, end - msg->data); - return mStatus_BadParamErr; - } - - newend = putHINFO(m, msg, end, authInfo, limit); - if (!newend) LogMsg("mDNSSendDNSMessage: putHINFO failed msg %p end %p, limit %p", msg->data, end, limit); // Not fatal - else end = newend; - - // Put all the integer values in IETF byte-order (MSB first, LSB second) - SwapDNSHeaderBytes(msg); - - if (authInfo) DNSDigest_SignMessage(msg, &end, authInfo, 0); // DNSDigest_SignMessage operates on message in network byte order - if (!end) { LogMsg("mDNSSendDNSMessage: DNSDigest_SignMessage failed"); status = mStatus_NoMemoryErr; } - else - { - // Send the packet on the wire - if (!sock) - status = mDNSPlatformSendUDP(m, msg, end, InterfaceID, src, dst, dstport); - else - { - mDNSu16 msglen = (mDNSu16)(end - (mDNSu8 *)msg); - mDNSu8 lenbuf[2] = { (mDNSu8)(msglen >> 8), (mDNSu8)(msglen & 0xFF) }; - long nsent = mDNSPlatformWriteTCP(sock, (char*)lenbuf, 2); // Should do scatter/gather here -- this is probably going out as two packets - if (nsent != 2) { LogMsg("mDNSSendDNSMessage: write msg length failed %d/%d", nsent, 2); status = mStatus_ConnFailed; } - else - { - nsent = mDNSPlatformWriteTCP(sock, (char *)msg, msglen); - if (nsent != msglen) { LogMsg("mDNSSendDNSMessage: write msg body failed %d/%d", nsent, msglen); status = mStatus_ConnFailed; } - } - } - } - - // Swap the integer values back the way they were (remember that numAdditionals may have been changed by putHINFO and/or SignMessage) - SwapDNSHeaderBytes(msg); - - // Dump the packet with the HINFO and TSIG - if (mDNS_PacketLoggingEnabled && !mDNSOpaque16IsZero(msg->h.id)) - DumpPacket(m, status, mDNStrue, sock && (sock->flags & kTCPSocketFlags_UseTLS) ? "TLS" : sock ? "TCP" : "UDP", mDNSNULL, src ? src->port : MulticastDNSPort, dst, dstport, msg, end); - - // put the number of additionals back the way it was - msg->h.numAdditionals = numAdditionals; - - return(status); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - RR List Management & Task Management -#endif - -mDNSexport void mDNS_Lock_(mDNS *const m, const char * const functionname) - { - // MUST grab the platform lock FIRST! - mDNSPlatformLock(m); - - // Normally, mDNS_reentrancy is zero and so is mDNS_busy - // However, when we call a client callback mDNS_busy is one, and we increment mDNS_reentrancy too - // If that client callback does mDNS API calls, mDNS_reentrancy and mDNS_busy will both be one - // If mDNS_busy != mDNS_reentrancy that's a bad sign - if (m->mDNS_busy != m->mDNS_reentrancy) - { - LogMsg("%s: mDNS_Lock: Locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", functionname, m->mDNS_busy, m->mDNS_reentrancy); -#if ForceAlerts - *(long*)0 = 0; -#endif - } - - // If this is an initial entry into the mDNSCore code, set m->timenow - // else, if this is a re-entrant entry into the mDNSCore code, m->timenow should already be set - if (m->mDNS_busy == 0) - { - if (m->timenow) - LogMsg("%s: mDNS_Lock: m->timenow already set (%ld/%ld)", functionname, m->timenow, mDNS_TimeNow_NoLock(m)); - m->timenow = mDNS_TimeNow_NoLock(m); - if (m->timenow == 0) m->timenow = 1; - } - else if (m->timenow == 0) - { - LogMsg("%s: mDNS_Lock: m->mDNS_busy is %ld but m->timenow not set", functionname, m->mDNS_busy); - m->timenow = mDNS_TimeNow_NoLock(m); - if (m->timenow == 0) m->timenow = 1; - } - - if (m->timenow_last - m->timenow > 0) - { - m->timenow_adjust += m->timenow_last - m->timenow; - LogMsg("%s: mDNSPlatformRawTime went backwards by %ld ticks; setting correction factor to %ld", functionname, m->timenow_last - m->timenow, m->timenow_adjust); - m->timenow = m->timenow_last; - } - m->timenow_last = m->timenow; - - // Increment mDNS_busy so we'll recognise re-entrant calls - m->mDNS_busy++; - } - -mDNSlocal AuthRecord *AnyLocalRecordReady(const mDNS *const m) - { - AuthRecord *rr; - for (rr = m->NewLocalRecords; rr; rr = rr->next) - if (LocalRecordReady(rr)) return rr; - return mDNSNULL; - } - -mDNSlocal mDNSs32 GetNextScheduledEvent(const mDNS *const m) - { - mDNSs32 e = m->timenow + 0x78000000; - if (m->mDNSPlatformStatus != mStatus_NoError) return(e); - if (m->NewQuestions) - { - if (m->NewQuestions->DelayAnswering) e = m->NewQuestions->DelayAnswering; - else return(m->timenow); - } - if (m->NewLocalOnlyQuestions) return(m->timenow); - if (m->NewLocalRecords && AnyLocalRecordReady(m)) return(m->timenow); - if (m->NewLocalOnlyRecords) return(m->timenow); - if (m->SPSProxyListChanged) return(m->timenow); - if (m->LocalRemoveEvents) return(m->timenow); - -#ifndef UNICAST_DISABLED - if (e - m->NextuDNSEvent > 0) e = m->NextuDNSEvent; - if (e - m->NextScheduledNATOp > 0) e = m->NextScheduledNATOp; - if (m->NextSRVUpdate && e - m->NextSRVUpdate > 0) e = m->NextSRVUpdate; -#endif - - if (e - m->NextCacheCheck > 0) e = m->NextCacheCheck; - if (e - m->NextScheduledSPS > 0) e = m->NextScheduledSPS; - // NextScheduledSPRetry only valid when DelaySleep not set - if (!m->DelaySleep && m->SleepLimit && e - m->NextScheduledSPRetry > 0) e = m->NextScheduledSPRetry; - if (m->DelaySleep && e - m->DelaySleep > 0) e = m->DelaySleep; - - if (m->SuppressSending) - { - if (e - m->SuppressSending > 0) e = m->SuppressSending; - } - else - { - if (e - m->NextScheduledQuery > 0) e = m->NextScheduledQuery; - if (e - m->NextScheduledProbe > 0) e = m->NextScheduledProbe; - if (e - m->NextScheduledResponse > 0) e = m->NextScheduledResponse; - } - if (e - m->NextScheduledStopTime > 0) e = m->NextScheduledStopTime; - return(e); - } - -mDNSexport void ShowTaskSchedulingError(mDNS *const m) - { - AuthRecord *rr; - mDNS_Lock(m); - - LogMsg("Task Scheduling Error: Continuously busy for more than a second"); - - // Note: To accurately diagnose *why* we're busy, the debugging code here needs to mirror the logic in GetNextScheduledEvent above - - if (m->NewQuestions && (!m->NewQuestions->DelayAnswering || m->timenow - m->NewQuestions->DelayAnswering >= 0)) - LogMsg("Task Scheduling Error: NewQuestion %##s (%s)", - m->NewQuestions->qname.c, DNSTypeName(m->NewQuestions->qtype)); - - if (m->NewLocalOnlyQuestions) - LogMsg("Task Scheduling Error: NewLocalOnlyQuestions %##s (%s)", - m->NewLocalOnlyQuestions->qname.c, DNSTypeName(m->NewLocalOnlyQuestions->qtype)); - - if (m->NewLocalRecords) - { - rr = AnyLocalRecordReady(m); - if (rr) LogMsg("Task Scheduling Error: NewLocalRecords %s", ARDisplayString(m, rr)); - } - - if (m->NewLocalOnlyRecords) LogMsg("Task Scheduling Error: NewLocalOnlyRecords"); - - if (m->SPSProxyListChanged) LogMsg("Task Scheduling Error: SPSProxyListChanged"); - if (m->LocalRemoveEvents) LogMsg("Task Scheduling Error: LocalRemoveEvents"); - - if (m->timenow - m->NextScheduledEvent >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledEvent %d", m->timenow - m->NextScheduledEvent); - -#ifndef UNICAST_DISABLED - if (m->timenow - m->NextuDNSEvent >= 0) - LogMsg("Task Scheduling Error: m->NextuDNSEvent %d", m->timenow - m->NextuDNSEvent); - if (m->timenow - m->NextScheduledNATOp >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledNATOp %d", m->timenow - m->NextScheduledNATOp); - if (m->NextSRVUpdate && m->timenow - m->NextSRVUpdate >= 0) - LogMsg("Task Scheduling Error: m->NextSRVUpdate %d", m->timenow - m->NextSRVUpdate); -#endif - - if (m->timenow - m->NextCacheCheck >= 0) - LogMsg("Task Scheduling Error: m->NextCacheCheck %d", m->timenow - m->NextCacheCheck); - if (m->timenow - m->NextScheduledSPS >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledSPS %d", m->timenow - m->NextScheduledSPS); - if (!m->DelaySleep && m->SleepLimit && m->timenow - m->NextScheduledSPRetry >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledSPRetry %d", m->timenow - m->NextScheduledSPRetry); - if (m->DelaySleep && m->timenow - m->DelaySleep >= 0) - LogMsg("Task Scheduling Error: m->DelaySleep %d", m->timenow - m->DelaySleep); - - if (m->SuppressSending && m->timenow - m->SuppressSending >= 0) - LogMsg("Task Scheduling Error: m->SuppressSending %d", m->timenow - m->SuppressSending); - if (m->timenow - m->NextScheduledQuery >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledQuery %d", m->timenow - m->NextScheduledQuery); - if (m->timenow - m->NextScheduledProbe >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledProbe %d", m->timenow - m->NextScheduledProbe); - if (m->timenow - m->NextScheduledResponse >= 0) - LogMsg("Task Scheduling Error: m->NextScheduledResponse %d", m->timenow - m->NextScheduledResponse); - - mDNS_Unlock(m); - } - -mDNSexport void mDNS_Unlock_(mDNS *const m, const char * const functionname) - { - // Decrement mDNS_busy - m->mDNS_busy--; - - // Check for locking failures - if (m->mDNS_busy != m->mDNS_reentrancy) - { - LogMsg("%s: mDNS_Unlock: Locking failure! mDNS_busy (%ld) != mDNS_reentrancy (%ld)", functionname, m->mDNS_busy, m->mDNS_reentrancy); -#if ForceAlerts - *(long*)0 = 0; -#endif - } - - // If this is a final exit from the mDNSCore code, set m->NextScheduledEvent and clear m->timenow - if (m->mDNS_busy == 0) - { - m->NextScheduledEvent = GetNextScheduledEvent(m); - if (m->timenow == 0) LogMsg("%s: mDNS_Unlock: ERROR! m->timenow aready zero", functionname); - m->timenow = 0; - } - - // MUST release the platform lock LAST! - mDNSPlatformUnlock(m); - } - -// *************************************************************************** -#if COMPILER_LIKES_PRAGMA_MARK -#pragma mark - -#pragma mark - Specialized mDNS version of vsnprintf -#endif - -static const struct mDNSprintf_format - { - unsigned leftJustify : 1; - unsigned forceSign : 1; - unsigned zeroPad : 1; - unsigned havePrecision : 1; - unsigned hSize : 1; - unsigned lSize : 1; - char altForm; - char sign; // +, - or space - unsigned int fieldWidth; - unsigned int precision; - } mDNSprintf_format_default = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; - -mDNSexport mDNSu32 mDNS_vsnprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, va_list arg) - { - mDNSu32 nwritten = 0; - int c; - if (buflen == 0) return(0); - buflen--; // Pre-reserve one space in the buffer for the terminating null - if (buflen == 0) goto exit; - - for (c = *fmt; c != 0; c = *++fmt) - { - if (c != '%') - { - *sbuffer++ = (char)c; - if (++nwritten >= buflen) goto exit; - } - else - { - unsigned int i=0, j; - // The mDNS Vsprintf Argument Conversion Buffer is used as a temporary holding area for - // generating decimal numbers, hexdecimal numbers, IP addresses, domain name strings, etc. - // The size needs to be enough for a 256-byte domain name plus some error text. - #define mDNS_VACB_Size 300 - char mDNS_VACB[mDNS_VACB_Size]; - #define mDNS_VACB_Lim (&mDNS_VACB[mDNS_VACB_Size]) - #define mDNS_VACB_Remain(s) ((mDNSu32)(mDNS_VACB_Lim - s)) - char *s = mDNS_VACB_Lim, *digits; - struct mDNSprintf_format F = mDNSprintf_format_default; - - while (1) // decode flags - { - c = *++fmt; - if (c == '-') F.leftJustify = 1; - else if (c == '+') F.forceSign = 1; - else if (c == ' ') F.sign = ' '; - else if (c == '#') F.altForm++; - else if (c == '0') F.zeroPad = 1; - else break; - } - - if (c == '*') // decode field width - { - int f = va_arg(arg, int); - if (f < 0) { f = -f; F.leftJustify = 1; } - F.fieldWidth = (unsigned int)f; - c = *++fmt; - } - else - { - for (; c >= '0' && c <= '9'; c = *++fmt) - F.fieldWidth = (10 * F.fieldWidth) + (c - '0'); - } - - if (c == '.') // decode precision - { - if ((c = *++fmt) == '*') - { F.precision = va_arg(arg, unsigned int); c = *++fmt; } - else for (; c >= '0' && c <= '9'; c = *++fmt) - F.precision = (10 * F.precision) + (c - '0'); - F.havePrecision = 1; - } - - if (F.leftJustify) F.zeroPad = 0; - - conv: - switch (c) // perform appropriate conversion - { - unsigned long n; - case 'h' : F.hSize = 1; c = *++fmt; goto conv; - case 'l' : // fall through - case 'L' : F.lSize = 1; c = *++fmt; goto conv; - case 'd' : - case 'i' : if (F.lSize) n = (unsigned long)va_arg(arg, long); - else n = (unsigned long)va_arg(arg, int); - if (F.hSize) n = (short) n; - if ((long) n < 0) { n = (unsigned long)-(long)n; F.sign = '-'; } - else if (F.forceSign) F.sign = '+'; - goto decimal; - case 'u' : if (F.lSize) n = va_arg(arg, unsigned long); - else n = va_arg(arg, unsigned int); - if (F.hSize) n = (unsigned short) n; - F.sign = 0; - goto decimal; - decimal: if (!F.havePrecision) - { - if (F.zeroPad) - { - F.precision = F.fieldWidth; - if (F.sign) --F.precision; - } - if (F.precision < 1) F.precision = 1; - } - if (F.precision > mDNS_VACB_Size - 1) - F.precision = mDNS_VACB_Size - 1; - for (i = 0; n; n /= 10, i++) *--s = (char)(n % 10 + '0'); - for (; i < F.precision; i++) *--s = '0'; - if (F.sign) { *--s = F.sign; i++; } - break; - - case 'o' : if (F.lSize) n = va_arg(arg, unsigned long); - else n = va_arg(arg, unsigned int); - if (F.hSize) n = (unsigned short) n; - if (!F.havePrecision) - { - if (F.zeroPad) F.precision = F.fieldWidth; - if (F.precision < 1) F.precision = 1; - } - if (F.precision > mDNS_VACB_Size - 1) - F.precision = mDNS_VACB_Size - 1; - for (i = 0; n; n /= 8, i++) *--s = (char)(n % 8 + '0'); - if (F.altForm && i && *s != '0') { *--s = '0'; i++; } - for (; i < F.precision; i++) *--s = '0'; - break; - - case 'a' : { - unsigned char *a = va_arg(arg, unsigned char *); - if (!a) { static char emsg[] = "<<NULL>>"; s = emsg; i = sizeof(emsg)-1; } - else - { - s = mDNS_VACB; // Adjust s to point to the start of the buffer, not the end - if (F.altForm) - { - mDNSAddr *ip = (mDNSAddr*)a; - switch (ip->type) - { - case mDNSAddrType_IPv4: F.precision = 4; a = (unsigned char *)&ip->ip.v4; break; - case mDNSAddrType_IPv6: F.precision = 16; a = (unsigned char *)&ip->ip.v6; break; - default: F.precision = 0; break; - } - } - if (F.altForm && !F.precision) - i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "<ZERO ADDRESS>"); - else switch (F.precision) - { - case 4: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%d.%d.%d.%d", - a[0], a[1], a[2], a[3]); break; - case 6: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%02X:%02X:%02X:%02X:%02X:%02X", - a[0], a[1], a[2], a[3], a[4], a[5]); break; - case 16: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), - "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X", - a[0x0], a[0x1], a[0x2], a[0x3], a[0x4], a[0x5], a[0x6], a[0x7], - a[0x8], a[0x9], a[0xA], a[0xB], a[0xC], a[0xD], a[0xE], a[0xF]); break; - default: i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "%s", "<< ERROR: Must specify" - " address size (i.e. %.4a=IPv4, %.6a=Ethernet, %.16a=IPv6) >>"); break; - } - } - } - break; - - case 'p' : F.havePrecision = F.lSize = 1; - F.precision = sizeof(void*) * 2; // 8 characters on 32-bit; 16 characters on 64-bit - case 'X' : digits = "0123456789ABCDEF"; - goto hexadecimal; - case 'x' : digits = "0123456789abcdef"; - hexadecimal:if (F.lSize) n = va_arg(arg, unsigned long); - else n = va_arg(arg, unsigned int); - if (F.hSize) n = (unsigned short) n; - if (!F.havePrecision) - { - if (F.zeroPad) - { - F.precision = F.fieldWidth; - if (F.altForm) F.precision -= 2; - } - if (F.precision < 1) F.precision = 1; - } - if (F.precision > mDNS_VACB_Size - 1) - F.precision = mDNS_VACB_Size - 1; - for (i = 0; n; n /= 16, i++) *--s = digits[n % 16]; - for (; i < F.precision; i++) *--s = '0'; - if (F.altForm) { *--s = (char)c; *--s = '0'; i += 2; } - break; - - case 'c' : *--s = (char)va_arg(arg, int); i = 1; break; - - case 's' : s = va_arg(arg, char *); - if (!s) { static char emsg[] = "<<NULL>>"; s = emsg; i = sizeof(emsg)-1; } - else switch (F.altForm) - { - case 0: i=0; - if (!F.havePrecision) // C string - while (s[i]) i++; - else - { - while ((i < F.precision) && s[i]) i++; - // Make sure we don't truncate in the middle of a UTF-8 character - // If last character we got was any kind of UTF-8 multi-byte character, - // then see if we have to back up. - // This is not as easy as the similar checks below, because - // here we can't assume it's safe to examine the *next* byte, so we - // have to confine ourselves to working only backwards in the string. - j = i; // Record where we got to - // Now, back up until we find first non-continuation-char - while (i>0 && (s[i-1] & 0xC0) == 0x80) i--; - // Now s[i-1] is the first non-continuation-char - // and (j-i) is the number of continuation-chars we found - if (i>0 && (s[i-1] & 0xC0) == 0xC0) // If we found a start-char - { - i--; // Tentatively eliminate this start-char as well - // Now (j-i) is the number of characters we're considering eliminating. - // To be legal UTF-8, the start-char must contain (j-i) one-bits, - // followed by a zero bit. If we shift it right by (7-(j-i)) bits - // (with sign extension) then the result has to be 0xFE. - // If this is right, then we reinstate the tentatively eliminated bytes. - if (((j-i) < 7) && (((s[i] >> (7-(j-i))) & 0xFF) == 0xFE)) i = j; - } - } - break; - case 1: i = (unsigned char) *s++; break; // Pascal string - case 2: { // DNS label-sequence name - unsigned char *a = (unsigned char *)s; - s = mDNS_VACB; // Adjust s to point to the start of the buffer, not the end - if (*a == 0) *s++ = '.'; // Special case for root DNS name - while (*a) - { - char buf[63*4+1]; - if (*a > 63) - { s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "<<INVALID LABEL LENGTH %u>>", *a); break; } - if (s + *a >= &mDNS_VACB[254]) - { s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "<<NAME TOO LONG>>"); break; } - // Need to use ConvertDomainLabelToCString to do proper escaping here, - // so it's clear what's a literal dot and what's a label separator - ConvertDomainLabelToCString((domainlabel*)a, buf); - s += mDNS_snprintf(s, mDNS_VACB_Remain(s), "%s.", buf); - a += 1 + *a; - } - i = (mDNSu32)(s - mDNS_VACB); - s = mDNS_VACB; // Reset s back to the start of the buffer - break; - } - } - // Make sure we don't truncate in the middle of a UTF-8 character (see similar comment below) - if (F.havePrecision && i > F.precision) - { i = F.precision; while (i>0 && (s[i] & 0xC0) == 0x80) i--; } - break; - - case 'n' : s = va_arg(arg, char *); - if (F.hSize) * (short *) s = (short)nwritten; - else if (F.lSize) * (long *) s = (long)nwritten; - else * (int *) s = (int)nwritten; - continue; - - default: s = mDNS_VACB; - i = mDNS_snprintf(mDNS_VACB, sizeof(mDNS_VACB), "<<UNKNOWN FORMAT CONVERSION CODE %%%c>>", c); - - case '%' : *sbuffer++ = (char)c; - if (++nwritten >= buflen) goto exit; - break; - } - - if (i < F.fieldWidth && !F.leftJustify) // Pad on the left - do { - *sbuffer++ = ' '; - if (++nwritten >= buflen) goto exit; - } while (i < --F.fieldWidth); - - // Make sure we don't truncate in the middle of a UTF-8 character. - // Note: s[i] is the first eliminated character; i.e. the next character *after* the last character of the - // allowed output. If s[i] is a UTF-8 continuation character, then we've cut a unicode character in half, - // so back up 'i' until s[i] is no longer a UTF-8 continuation character. (if the input was proprly - // formed, s[i] will now be the UTF-8 start character of the multi-byte character we just eliminated). - if (i > buflen - nwritten) - { i = buflen - nwritten; while (i>0 && (s[i] & 0xC0) == 0x80) i--; } - for (j=0; j<i; j++) *sbuffer++ = *s++; // Write the converted result - nwritten += i; - if (nwritten >= buflen) goto exit; - - for (; i < F.fieldWidth; i++) // Pad on the right - { - *sbuffer++ = ' '; - if (++nwritten >= buflen) goto exit; - } - } - } - exit: - *sbuffer++ = 0; - return(nwritten); - } - -mDNSexport mDNSu32 mDNS_snprintf(char *sbuffer, mDNSu32 buflen, const char *fmt, ...) - { - mDNSu32 length; - - va_list ptr; - va_start(ptr,fmt); - length = mDNS_vsnprintf(sbuffer, buflen, fmt, ptr); - va_end(ptr); - - return(length); - } |