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Diffstat (limited to 'src/3rdparty/tinycbor/src/cborparser.c')
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diff --git a/src/3rdparty/tinycbor/src/cborparser.c b/src/3rdparty/tinycbor/src/cborparser.c new file mode 100644 index 0000000000..65b0b4b5c8 --- /dev/null +++ b/src/3rdparty/tinycbor/src/cborparser.c @@ -0,0 +1,1522 @@ +/**************************************************************************** +** +** Copyright (C) 2018 Intel Corporation +** +** Permission is hereby granted, free of charge, to any person obtaining a copy +** of this software and associated documentation files (the "Software"), to deal +** in the Software without restriction, including without limitation the rights +** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +** copies of the Software, and to permit persons to whom the Software is +** furnished to do so, subject to the following conditions: +** +** The above copyright notice and this permission notice shall be included in +** all copies or substantial portions of the Software. +** +** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +** THE SOFTWARE. +** +****************************************************************************/ + +#ifndef _BSD_SOURCE +#define _BSD_SOURCE 1 +#endif +#ifndef _DEFAULT_SOURCE +#define _DEFAULT_SOURCE 1 +#endif +#ifndef __STDC_LIMIT_MACROS +# define __STDC_LIMIT_MACROS 1 +#endif + +#include "cbor.h" +#include "cborinternal_p.h" +#include "compilersupport_p.h" + +#include <string.h> + +/** + * \defgroup CborParsing Parsing CBOR streams + * \brief Group of functions used to parse CBOR streams. + * + * TinyCBOR provides functions for pull-based stream parsing of a CBOR-encoded + * payload. The main data type for the parsing is a CborValue, which behaves + * like an iterator and can be used to extract the encoded data. It is first + * initialized with a call to cbor_parser_init() and is usually used to extract + * exactly one item, most often an array or map. + * + * Nested CborValue objects can be parsed using cbor_value_enter_container(). + * Each call to cbor_value_enter_container() must be matched by a call to + * cbor_value_leave_container(), with the exact same parameters. + * + * The example below initializes a CborParser object, begins the parsing with a + * CborValue and decodes a single integer: + * + * \code + * int extract_int(const uint8_t *buffer, size_t len) + * { + * CborParser parser; + * CborValue value; + * int result; + * cbor_parser_init(buffer, len, 0, &parser, &value); + * cbor_value_get_int(&value, &result); + * return result; + * } + * \endcode + * + * The code above does no error checking, which means it assumes the data comes + * from a source trusted to send one properly-encoded integer. The following + * example does the exact same operation, but includes error checking and + * returns 0 on parsing failure: + * + * \code + * int extract_int(const uint8_t *buffer, size_t len) + * { + * CborParser parser; + * CborValue value; + * int result; + * if (cbor_parser_init(buffer, len, 0, &parser, &value) != CborNoError) + * return 0; + * if (!cbor_value_is_integer(&value) || + * cbor_value_get_int(&value, &result) != CborNoError) + * return 0; + * return result; + * } + * \endcode + * + * Note, in the example above, that one can't distinguish a parsing failure + * from an encoded value of zero. Reporting a parsing error is left as an + * exercise to the reader. + * + * The code above does not execute a range-check either: it is possible that + * the value decoded from the CBOR stream encodes a number larger than what can + * be represented in a variable of type \c{int}. If detecting that case is + * important, the code should call cbor_value_get_int_checked() instead. + * + * <h3 class="groupheader">Memory and parsing constraints</h3> + * + * TinyCBOR is designed to run with little memory and with minimal overhead. + * Except where otherwise noted, the parser functions always run on constant + * time (O(1)), do not recurse and never allocate memory (thus, stack usage is + * bounded and is O(1)). + * + * <h3 class="groupheader">Error handling and preconditions</h3> + * + * All functions operating on a CborValue return a CborError condition, with + * CborNoError standing for the normal situation in which no parsing error + * occurred. All functions may return parsing errors in case the stream cannot + * be decoded properly, be it due to corrupted data or due to reaching the end + * of the input buffer. + * + * Error conditions must not be ignored. All decoder functions have undefined + * behavior if called after an error has been reported, and may crash. + * + * Some functions are also documented to have preconditions, like + * cbor_value_get_int() requiring that the input be an integral value. + * Violation of preconditions also results in undefined behavior and the + * program may crash. + */ + +/** + * \addtogroup CborParsing + * @{ + */ + +/** + * \struct CborValue + * + * This type contains one value parsed from the CBOR stream. Each CborValue + * behaves as an iterator in a StAX-style parser. + * + * \if privatedocs + * Implementation details: the CborValue contains these fields: + * \list + * \li ptr: pointer to the actual data + * \li flags: flags from the decoder + * \li extra: partially decoded integer value (0, 1 or 2 bytes) + * \li remaining: remaining items in this collection after this item or UINT32_MAX if length is unknown + * \endlist + * \endif + */ + +static uint64_t extract_number_and_advance(CborValue *it) +{ + /* This function is only called after we've verified that the number + * here is valid, so we can just use _cbor_value_extract_int64_helper. */ + uint8_t descriptor; + uint64_t v = _cbor_value_extract_int64_helper(it); + + read_bytes_unchecked(it, &descriptor, 0, 1); + descriptor &= SmallValueMask; + + size_t bytesNeeded = descriptor < Value8Bit ? 0 : (1 << (descriptor - Value8Bit)); + advance_bytes(it, bytesNeeded + 1); + + return v; +} + +static bool is_fixed_type(uint8_t type) +{ + return type != CborTextStringType && type != CborByteStringType && type != CborArrayType && + type != CborMapType; +} + +static CborError preparse_value(CborValue *it) +{ + enum { + /* flags to keep */ + FlagsToKeep = CborIteratorFlag_ContainerIsMap | CborIteratorFlag_NextIsMapKey + }; + uint8_t descriptor; + + /* are we at the end? */ + it->type = CborInvalidType; + it->flags &= FlagsToKeep; + if (!read_bytes(it, &descriptor, 0, 1)) + return CborErrorUnexpectedEOF; + + uint8_t type = descriptor & MajorTypeMask; + it->type = type; + it->extra = (descriptor &= SmallValueMask); + + if (descriptor > Value64Bit) { + if (unlikely(descriptor != IndefiniteLength)) + return type == CborSimpleType ? CborErrorUnknownType : CborErrorIllegalNumber; + if (likely(!is_fixed_type(type))) { + /* special case */ + it->flags |= CborIteratorFlag_UnknownLength; + it->type = type; + return CborNoError; + } + return type == CborSimpleType ? CborErrorUnexpectedBreak : CborErrorIllegalNumber; + } + + size_t bytesNeeded = descriptor < Value8Bit ? 0 : (1 << (descriptor - Value8Bit)); + + if (bytesNeeded) { + if (!can_read_bytes(it, bytesNeeded + 1)) + return CborErrorUnexpectedEOF; + + it->extra = 0; + + /* read up to 16 bits into it->extra */ + if (bytesNeeded <= 2) { + read_bytes_unchecked(it, &it->extra, 1, bytesNeeded); + if (bytesNeeded == 2) + it->extra = cbor_ntohs(it->extra); + } else { + cbor_static_assert(CborIteratorFlag_IntegerValueTooLarge == (Value32Bit & 3)); + cbor_static_assert((CborIteratorFlag_IntegerValueIs64Bit | + CborIteratorFlag_IntegerValueTooLarge) == (Value64Bit & 3)); + it->flags |= (descriptor & 3); + } + } + + uint8_t majortype = type >> MajorTypeShift; + if (majortype == NegativeIntegerType) { + it->flags |= CborIteratorFlag_NegativeInteger; + it->type = CborIntegerType; + } else if (majortype == SimpleTypesType) { + switch (descriptor) { + case FalseValue: + it->extra = false; + it->type = CborBooleanType; + break; + + case SinglePrecisionFloat: + case DoublePrecisionFloat: + it->flags |= CborIteratorFlag_IntegerValueTooLarge; + /* fall through */ + case TrueValue: + case NullValue: + case UndefinedValue: + case HalfPrecisionFloat: + read_bytes_unchecked(it, &it->type, 0, 1); + break; + + case SimpleTypeInNextByte: +#ifndef CBOR_PARSER_NO_STRICT_CHECKS + if (unlikely(it->extra < 32)) { + it->type = CborInvalidType; + return CborErrorIllegalSimpleType; + } +#endif + break; + + case 28: + case 29: + case 30: + case Break: + cbor_assert(false); /* these conditions can't be reached */ + return CborErrorUnexpectedBreak; + } + } + + return CborNoError; +} + +static CborError preparse_next_value_nodecrement(CborValue *it) +{ + uint8_t byte; + if (it->remaining == UINT32_MAX && read_bytes(it, &byte, 0, 1) && byte == (uint8_t)BreakByte) { + /* end of map or array */ + if ((it->flags & CborIteratorFlag_ContainerIsMap && it->flags & CborIteratorFlag_NextIsMapKey) + || it->type == CborTagType) { + /* but we weren't expecting it! */ + return CborErrorUnexpectedBreak; + } + it->type = CborInvalidType; + it->remaining = 0; + it->flags |= CborIteratorFlag_UnknownLength; /* leave_container must consume the Break */ + return CborNoError; + } + + return preparse_value(it); +} + +static CborError preparse_next_value(CborValue *it) +{ + /* tags don't count towards item totals or whether we've successfully + * read a map's key or value */ + bool itemCounts = it->type != CborTagType; + + if (it->remaining != UINT32_MAX) { + if (itemCounts && --it->remaining == 0) { + it->type = CborInvalidType; + it->flags &= ~CborIteratorFlag_UnknownLength; /* no Break to consume */ + return CborNoError; + } + } + if (itemCounts) { + /* toggle the flag indicating whether this was a map key */ + it->flags ^= CborIteratorFlag_NextIsMapKey; + } + return preparse_next_value_nodecrement(it); +} + +static CborError advance_internal(CborValue *it) +{ + uint64_t length = extract_number_and_advance(it); + + if (it->type == CborByteStringType || it->type == CborTextStringType) { + cbor_assert(length == (size_t)length); + cbor_assert((it->flags & CborIteratorFlag_UnknownLength) == 0); + advance_bytes(it, length); + } + + return preparse_next_value(it); +} + +/** \internal + * + * Decodes the CBOR integer value when it is larger than the 16 bits available + * in value->extra. This function requires that value->flags have the + * CborIteratorFlag_IntegerValueTooLarge flag set. + * + * This function is also used to extract single- and double-precision floating + * point values (SinglePrecisionFloat == Value32Bit and DoublePrecisionFloat == + * Value64Bit). + */ +uint64_t _cbor_value_decode_int64_internal(const CborValue *value) +{ + cbor_assert(value->flags & CborIteratorFlag_IntegerValueTooLarge || + value->type == CborFloatType || value->type == CborDoubleType); + if (value->flags & CborIteratorFlag_IntegerValueIs64Bit) + return read_uint64(value, 1); + + return read_uint32(value, 1); +} + +/** + * Initializes the CBOR parser for parsing \a size bytes beginning at \a + * buffer. Parsing will use flags set in \a flags. The iterator to the first + * element is returned in \a it. + * + * The \a parser structure needs to remain valid throughout the decoding + * process. It is not thread-safe to share one CborParser among multiple + * threads iterating at the same time, but the object can be copied so multiple + * threads can iterate. + */ +CborError cbor_parser_init(const uint8_t *buffer, size_t size, int flags, CborParser *parser, CborValue *it) +{ + memset(parser, 0, sizeof(*parser)); + parser->source.end = buffer + size; + parser->flags = (enum CborParserGlobalFlags)flags; + it->parser = parser; + it->source.ptr = buffer; + it->remaining = 1; /* there's one type altogether, usually an array or map */ + it->flags = 0; + return preparse_value(it); +} + +CborError cbor_parser_init_reader(const struct CborParserOperations *ops, CborParser *parser, CborValue *it, void *token) +{ + memset(parser, 0, sizeof(*parser)); + parser->source.ops = ops; + parser->flags = CborParserFlag_ExternalSource; + it->parser = parser; + it->source.token = token; + it->remaining = 1; + return preparse_value(it); +} + +/** + * \fn bool cbor_value_at_end(const CborValue *it) + * + * Returns true if \a it has reached the end of the iteration, usually when + * advancing after the last item in an array or map. + * + * In the case of the outermost CborValue object, this function returns true + * after decoding a single element. A pointer to the first byte of the + * remaining data (if any) can be obtained with cbor_value_get_next_byte(). + * + * \sa cbor_value_advance(), cbor_value_is_valid(), cbor_value_get_next_byte() + */ + +/** + * \fn const uint8_t *cbor_value_get_next_byte(const CborValue *it) + * + * Returns a pointer to the next byte that would be decoded if this CborValue + * object were advanced. + * + * This function is useful if cbor_value_at_end() returns true for the + * outermost CborValue: the pointer returned is the first byte of the data + * remaining in the buffer, if any. Code can decide whether to begin decoding a + * new CBOR data stream from this point, or parse some other data appended to + * the same buffer. + * + * This function may be used even after a parsing error. If that occurred, + * then this function returns a pointer to where the parsing error occurred. + * Note that the error recovery is not precise and the pointer may not indicate + * the exact byte containing bad data. + * + * This function makes sense only when using a linear buffer (that is, when the + * parser is initialize by cbor_parser_init()). If using an external source, + * this function may return garbage; instead, consult the external source itself + * to find out more details about the presence of more data. + * + * \sa cbor_value_at_end() + */ + +CborError cbor_value_reparse(CborValue *it) +{ + if (it->flags & CborIteratorFlag_IteratingStringChunks) + return CborNoError; + return preparse_next_value_nodecrement(it); +} + +/** + * \fn bool cbor_value_is_valid(const CborValue *it) + * + * Returns true if the iterator \a it contains a valid value. Invalid iterators + * happen when iteration reaches the end of a container (see \ref + * cbor_value_at_end()) or when a search function resulted in no matches. + * + * \sa cbor_value_advance(), cbor_value_at_end(), cbor_value_get_type() + */ + +/** + * Performs a basic validation of the CBOR stream pointed by \a it and returns + * the error it found. If no error was found, it returns CborNoError and the + * application can iterate over the items with certainty that no other errors + * will appear during parsing. + * + * A basic validation checks for: + * \list + * \li absence of undefined additional information bytes; + * \li well-formedness of all numbers, lengths, and simple values; + * \li string contents match reported sizes; + * \li arrays and maps contain the number of elements they are reported to have; + * \endlist + * + * For further checks, see cbor_value_validate(). + * + * This function has the same timing and memory requirements as + * cbor_value_advance(). + * + * \sa cbor_value_validate(), cbor_value_advance() + */ +CborError cbor_value_validate_basic(const CborValue *it) +{ + CborValue value = *it; + return cbor_value_advance(&value); +} + +/** + * Advances the CBOR value \a it by one fixed-size position. Fixed-size types + * are: integers, tags, simple types (including boolean, null and undefined + * values) and floating point types. + * + * If the type is not of fixed size, this function has undefined behavior. Code + * must be sure that the current type is one of the fixed-size types before + * calling this function. This function is provided because it can guarantee + * that it runs in constant time (O(1)). + * + * If the caller is not able to determine whether the type is fixed or not, code + * can use the cbor_value_advance() function instead. + * + * \sa cbor_value_at_end(), cbor_value_advance(), cbor_value_enter_container(), cbor_value_leave_container() + */ +CborError cbor_value_advance_fixed(CborValue *it) +{ + cbor_assert(it->type != CborInvalidType); + cbor_assert(is_fixed_type(it->type)); + if (!it->remaining) + return CborErrorAdvancePastEOF; + return advance_internal(it); +} + +static CborError advance_recursive(CborValue *it, int nestingLevel) +{ + if (is_fixed_type(it->type)) + return advance_internal(it); + + if (!cbor_value_is_container(it)) { + size_t len = SIZE_MAX; + return _cbor_value_copy_string(it, NULL, &len, it); + } + + /* map or array */ + if (nestingLevel == 0) + return CborErrorNestingTooDeep; + + CborError err; + CborValue recursed; + err = cbor_value_enter_container(it, &recursed); + if (err) + return err; + while (!cbor_value_at_end(&recursed)) { + err = advance_recursive(&recursed, nestingLevel - 1); + if (err) + return err; + } + return cbor_value_leave_container(it, &recursed); +} + + +/** + * Advances the CBOR value \a it by one element, skipping over containers. + * Unlike cbor_value_advance_fixed(), this function can be called on a CBOR + * value of any type. However, if the type is a container (map or array) or a + * string with a chunked payload, this function will not run in constant time + * and will recurse into itself (it will run on O(n) time for the number of + * elements or chunks and will use O(n) memory for the number of nested + * containers). + * + * The number of recursions can be limited at compile time to avoid stack + * exhaustion in constrained systems. + * + * \sa cbor_value_at_end(), cbor_value_advance_fixed(), cbor_value_enter_container(), cbor_value_leave_container() + */ +CborError cbor_value_advance(CborValue *it) +{ + cbor_assert(it->type != CborInvalidType); + if (!it->remaining) + return CborErrorAdvancePastEOF; + return advance_recursive(it, CBOR_PARSER_MAX_RECURSIONS); +} + +/** + * \fn bool cbor_value_is_tag(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR tag. + * + * \sa cbor_value_get_tag(), cbor_value_skip_tag() + */ + +/** + * \fn CborError cbor_value_get_tag(const CborValue *value, CborTag *result) + * + * Retrieves the CBOR tag value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to a CBOR tag value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_tag is recommended. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_tag() + */ + +/** + * Advances the CBOR value \a it until it no longer points to a tag. If \a it is + * already not pointing to a tag, then this function returns it unchanged. + * + * This function does not run in constant time: it will run on O(n) for n being + * the number of tags. It does use constant memory (O(1) memory requirements). + * + * \sa cbor_value_advance_fixed(), cbor_value_advance() + */ +CborError cbor_value_skip_tag(CborValue *it) +{ + while (cbor_value_is_tag(it)) { + CborError err = cbor_value_advance_fixed(it); + if (err) + return err; + } + return CborNoError; +} + +/** + * \fn bool cbor_value_is_container(const CborValue *it) + * + * Returns true if the \a it value is a container and requires recursion in + * order to decode (maps and arrays), false otherwise. + */ + +/** + * Creates a CborValue iterator pointing to the first element of the container + * represented by \a it and saves it in \a recursed. The \a it container object + * needs to be kept and passed again to cbor_value_leave_container() in order + * to continue iterating past this container. + * + * The \a it CborValue iterator must point to a container. + * + * \sa cbor_value_is_container(), cbor_value_leave_container(), cbor_value_advance() + */ +CborError cbor_value_enter_container(const CborValue *it, CborValue *recursed) +{ + cbor_static_assert(CborIteratorFlag_ContainerIsMap == (CborMapType & ~CborArrayType)); + cbor_assert(cbor_value_is_container(it)); + *recursed = *it; + + if (it->flags & CborIteratorFlag_UnknownLength) { + recursed->remaining = UINT32_MAX; + advance_bytes(recursed, 1); + } else { + uint64_t len = extract_number_and_advance(recursed); + + recursed->remaining = (uint32_t)len; + if (recursed->remaining != len || len == UINT32_MAX) { + /* back track the pointer to indicate where the error occurred */ + copy_current_position(recursed, it); + return CborErrorDataTooLarge; + } + if (recursed->type == CborMapType) { + /* maps have keys and values, so we need to multiply by 2 */ + if (recursed->remaining > UINT32_MAX / 2) { + /* back track the pointer to indicate where the error occurred */ + copy_current_position(recursed, it); + return CborErrorDataTooLarge; + } + recursed->remaining *= 2; + } + if (len == 0) { + /* the case of the empty container */ + recursed->type = CborInvalidType; + return CborNoError; + } + } + recursed->flags = (recursed->type & CborIteratorFlag_ContainerIsMap); + return preparse_next_value_nodecrement(recursed); +} + +/** + * Updates \a it to point to the next element after the container. The \a + * recursed object needs to point to the element obtained either by advancing + * the last element of the container (via cbor_value_advance(), + * cbor_value_advance_fixed(), a nested cbor_value_leave_container(), or the \c + * next pointer from cbor_value_copy_string() or cbor_value_dup_string()). + * + * The \a it and \a recursed parameters must be the exact same as passed to + * cbor_value_enter_container(). + * + * \sa cbor_value_enter_container(), cbor_value_at_end() + */ +CborError cbor_value_leave_container(CborValue *it, const CborValue *recursed) +{ + cbor_assert(cbor_value_is_container(it)); + cbor_assert(recursed->type == CborInvalidType); + + copy_current_position(it, recursed); + if (recursed->flags & CborIteratorFlag_UnknownLength) + advance_bytes(it, 1); + return preparse_next_value(it); +} + + +/** + * \fn CborType cbor_value_get_type(const CborValue *value) + * + * Returns the type of the CBOR value that the iterator \a value points to. If + * \a value does not point to a valid value, this function returns \ref + * CborInvalidType. + * + * TinyCBOR also provides functions to test directly if a given CborValue object + * is of a given type, like cbor_value_is_text_string() and cbor_value_is_null(). + * + * \sa cbor_value_is_valid() + */ + +/** + * \fn bool cbor_value_is_null(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR null type. + * + * \sa cbor_value_is_valid(), cbor_value_is_undefined() + */ + +/** + * \fn bool cbor_value_is_undefined(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR undefined type. + * + * \sa cbor_value_is_valid(), cbor_value_is_null() + */ + +/** + * \fn bool cbor_value_is_boolean(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR boolean + * type (true or false). + * + * \sa cbor_value_is_valid(), cbor_value_get_boolean() + */ + +/** + * \fn CborError cbor_value_get_boolean(const CborValue *value, bool *result) + * + * Retrieves the boolean value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to a boolean value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_boolean is recommended. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_boolean() + */ + +/** + * \fn bool cbor_value_is_simple_type(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR Simple Type + * type (other than true, false, null and undefined). + * + * \sa cbor_value_is_valid(), cbor_value_get_simple_type() + */ + +/** + * \fn CborError cbor_value_get_simple_type(const CborValue *value, uint8_t *result) + * + * Retrieves the CBOR Simple Type value that \a value points to and stores it + * in \a result. If the iterator \a value does not point to a simple_type + * value, the behavior is undefined, so checking with \ref cbor_value_get_type + * or with \ref cbor_value_is_simple_type is recommended. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_simple_type() + */ + +/** + * \fn bool cbor_value_is_integer(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR integer + * type. + * + * \sa cbor_value_is_valid(), cbor_value_get_int, cbor_value_get_int64, cbor_value_get_uint64, cbor_value_get_raw_integer + */ + +/** + * \fn bool cbor_value_is_unsigned_integer(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR unsigned + * integer type (positive values or zero). + * + * \sa cbor_value_is_valid(), cbor_value_get_uint64() + */ + +/** + * \fn bool cbor_value_is_negative_integer(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR negative + * integer type. + * + * \sa cbor_value_is_valid(), cbor_value_get_int, cbor_value_get_int64, cbor_value_get_raw_integer + */ + +/** + * \fn CborError cbor_value_get_int(const CborValue *value, int *result) + * + * Retrieves the CBOR integer value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to an integer value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_integer is recommended. + * + * Note that this function does not do range-checking: integral values that do + * not fit in a variable of type \c{int} are silently truncated to fit. Use + * cbor_value_get_int_checked() if that is not acceptable. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer() + */ + +/** + * \fn CborError cbor_value_get_int64(const CborValue *value, int64_t *result) + * + * Retrieves the CBOR integer value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to an integer value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_integer is recommended. + * + * Note that this function does not do range-checking: integral values that do + * not fit in a variable of type \c{int64_t} are silently truncated to fit. Use + * cbor_value_get_int64_checked() that is not acceptable. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer() + */ + +/** + * \fn CborError cbor_value_get_uint64(const CborValue *value, uint64_t *result) + * + * Retrieves the CBOR integer value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to an unsigned integer + * value, the behavior is undefined, so checking with \ref cbor_value_get_type + * or with \ref cbor_value_is_unsigned_integer is recommended. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_unsigned_integer() + */ + +/** + * \fn CborError cbor_value_get_raw_integer(const CborValue *value, uint64_t *result) + * + * Retrieves the CBOR integer value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to an integer value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_integer is recommended. + * + * This function is provided because CBOR negative integers can assume values + * that cannot be represented with normal 64-bit integer variables. + * + * If the integer is unsigned (that is, if cbor_value_is_unsigned_integer() + * returns true), then \a result will contain the actual value. If the integer + * is negative, then \a result will contain the absolute value of that integer, + * minus one. That is, \c {actual = -result - 1}. On architectures using two's + * complement for representation of negative integers, it is equivalent to say + * that \a result will contain the bitwise negation of the actual value. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer() + */ + +/** + * Retrieves the CBOR integer value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to an integer value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_integer is recommended. + * + * Unlike \ref cbor_value_get_int64(), this function performs a check to see if the + * stored integer fits in \a result without data loss. If the number is outside + * the valid range for the data type, this function returns the recoverable + * error CborErrorDataTooLarge. In that case, use either + * cbor_value_get_uint64() (if the number is positive) or + * cbor_value_get_raw_integer(). + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer(), cbor_value_get_int64() + */ +CborError cbor_value_get_int64_checked(const CborValue *value, int64_t *result) +{ + cbor_assert(cbor_value_is_integer(value)); + uint64_t v = _cbor_value_extract_int64_helper(value); + + /* Check before converting, as the standard says (C11 6.3.1.3 paragraph 3): + * "[if] the new type is signed and the value cannot be represented in it; either the + * result is implementation-defined or an implementation-defined signal is raised." + * + * The range for int64_t is -2^63 to 2^63-1 (int64_t is required to be + * two's complement, C11 7.20.1.1 paragraph 3), which in CBOR is + * represented the same way, differing only on the "sign bit" (the major + * type). + */ + + if (unlikely(v > (uint64_t)INT64_MAX)) + return CborErrorDataTooLarge; + + *result = v; + if (value->flags & CborIteratorFlag_NegativeInteger) + *result = -*result - 1; + return CborNoError; +} + +/** + * Retrieves the CBOR integer value that \a value points to and stores it in \a + * result. If the iterator \a value does not point to an integer value, the + * behavior is undefined, so checking with \ref cbor_value_get_type or with + * \ref cbor_value_is_integer is recommended. + * + * Unlike \ref cbor_value_get_int(), this function performs a check to see if the + * stored integer fits in \a result without data loss. If the number is outside + * the valid range for the data type, this function returns the recoverable + * error CborErrorDataTooLarge. In that case, use one of the other integer + * functions to obtain the value. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_integer(), cbor_value_get_int64(), + * cbor_value_get_uint64(), cbor_value_get_int64_checked(), cbor_value_get_raw_integer() + */ +CborError cbor_value_get_int_checked(const CborValue *value, int *result) +{ + cbor_assert(cbor_value_is_integer(value)); + uint64_t v = _cbor_value_extract_int64_helper(value); + + /* Check before converting, as the standard says (C11 6.3.1.3 paragraph 3): + * "[if] the new type is signed and the value cannot be represented in it; either the + * result is implementation-defined or an implementation-defined signal is raised." + * + * But we can convert from signed to unsigned without fault (paragraph 2). + * + * The range for int is implementation-defined and int is not guaranteed to use + * two's complement representation (although int32_t is). + */ + + if (value->flags & CborIteratorFlag_NegativeInteger) { + if (unlikely(v > (unsigned) -(INT_MIN + 1))) + return CborErrorDataTooLarge; + + *result = (int)v; + *result = -*result - 1; + } else { + if (unlikely(v > (uint64_t)INT_MAX)) + return CborErrorDataTooLarge; + + *result = (int)v; + } + return CborNoError; + +} + +/** + * \fn bool cbor_value_is_length_known(const CborValue *value) + * + * Returns true if the length of this type is known without calculation. That + * is, if the length of this CBOR string, map or array is encoded in the data + * stream, this function returns true. If the length is not encoded, it returns + * false. + * + * If the length is known, code can call cbor_value_get_string_length(), + * cbor_value_get_array_length() or cbor_value_get_map_length() to obtain the + * length. If the length is not known but is necessary, code can use the + * cbor_value_calculate_string_length() function (no equivalent function is + * provided for maps and arrays). + */ + +/** + * \fn bool cbor_value_is_text_string(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR text + * string. CBOR text strings are UTF-8 encoded and usually contain + * human-readable text. + * + * \sa cbor_value_is_valid(), cbor_value_get_string_length(), cbor_value_calculate_string_length(), + * cbor_value_copy_text_string(), cbor_value_dup_text_string() + */ + +/** + * \fn bool cbor_value_is_byte_string(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR text + * string. CBOR byte strings are binary data with no specified encoding or + * format. + * + * \sa cbor_value_is_valid(), cbor_value_get_string_length(), cbor_value_calculate_string_length(), + * cbor_value_copy_byte_string(), cbor_value_dup_byte_string() + */ + +/** + * \fn CborError cbor_value_get_string_length(const CborValue *value, size_t *length) + * + * Extracts the length of the byte or text string that \a value points to and + * stores it in \a result. If the iterator \a value does not point to a text + * string or a byte string, the behaviour is undefined, so checking with \ref + * cbor_value_get_type, with \ref cbor_value_is_text_string or \ref + * cbor_value_is_byte_string is recommended. + * + * If the length of this string is not encoded in the CBOR data stream, this + * function will return the recoverable error CborErrorUnknownLength. You may + * also check whether that is the case by using cbor_value_is_length_known(). + * + * If the length of the string is required but the length was not encoded, use + * cbor_value_calculate_string_length(), but note that that function does not + * run in constant time. + * + * \note On 32-bit platforms, this function will return error condition of \ref + * CborErrorDataTooLarge if the stream indicates a length that is too big to + * fit in 32-bit. + * + * \sa cbor_value_is_valid(), cbor_value_is_length_known(), cbor_value_calculate_string_length() + */ + +/** + * Calculates the length of the byte or text string that \a value points to and + * stores it in \a len. If the iterator \a value does not point to a text + * string or a byte string, the behaviour is undefined, so checking with \ref + * cbor_value_get_type, with \ref cbor_value_is_text_string or \ref + * cbor_value_is_byte_string is recommended. + * + * This function is different from cbor_value_get_string_length() in that it + * calculates the length even for strings sent in chunks. For that reason, this + * function may not run in constant time (it will run in O(n) time on the + * number of chunks). It does use constant memory (O(1)). + * + * \note On 32-bit platforms, this function will return error condition of \ref + * CborErrorDataTooLarge if the stream indicates a length that is too big to + * fit in 32-bit. + * + * \sa cbor_value_get_string_length(), cbor_value_copy_text_string(), cbor_value_copy_byte_string(), cbor_value_is_length_known() + */ +CborError cbor_value_calculate_string_length(const CborValue *value, size_t *len) +{ + *len = SIZE_MAX; + return _cbor_value_copy_string(value, NULL, len, NULL); +} + +CborError _cbor_value_begin_string_iteration(CborValue *it) +{ + it->flags |= CborIteratorFlag_IteratingStringChunks | + CborIteratorFlag_BeforeFirstStringChunk; + if (!cbor_value_is_length_known(it)) { + /* chunked string: we're before the first chunk; + * advance to the first chunk */ + advance_bytes(it, 1); + } + + return CborNoError; +} + +CborError _cbor_value_finish_string_iteration(CborValue *it) +{ + if (!cbor_value_is_length_known(it)) + advance_bytes(it, 1); /* skip the Break */ + + return preparse_next_value(it); +} + +static CborError get_string_chunk_size(const CborValue *it, size_t *offset, size_t *len) +{ + uint8_t descriptor; + size_t bytesNeeded = 1; + + if (cbor_value_is_length_known(it) && (it->flags & CborIteratorFlag_BeforeFirstStringChunk) == 0) + return CborErrorNoMoreStringChunks; + + /* are we at the end? */ + if (!read_bytes(it, &descriptor, 0, 1)) + return CborErrorUnexpectedEOF; + + if (descriptor == BreakByte) + return CborErrorNoMoreStringChunks; + if ((descriptor & MajorTypeMask) != it->type) + return CborErrorIllegalType; + + /* find the string length */ + descriptor &= SmallValueMask; + if (descriptor < Value8Bit) { + *len = descriptor; + } else if (unlikely(descriptor > Value64Bit)) { + return CborErrorIllegalNumber; + } else { + uint64_t val; + bytesNeeded = (size_t)(1 << (descriptor - Value8Bit)); + if (!can_read_bytes(it, 1 + bytesNeeded)) + return CborErrorUnexpectedEOF; + + if (descriptor <= Value16Bit) { + if (descriptor == Value16Bit) + val = read_uint16(it, 1); + else + val = read_uint8(it, 1); + } else { + if (descriptor == Value32Bit) + val = read_uint32(it, 1); + else + val = read_uint64(it, 1); + } + + *len = val; + if (*len != val) + return CborErrorDataTooLarge; + + ++bytesNeeded; + } + + *offset = bytesNeeded; + return CborNoError; +} + +CborError _cbor_value_get_string_chunk_size(const CborValue *value, size_t *len) +{ + size_t offset; + return get_string_chunk_size(value, &offset, len); +} + +static CborError get_string_chunk(CborValue *it, const void **bufferptr, size_t *len) +{ + size_t offset; + CborError err = get_string_chunk_size(it, &offset, len); + if (err) + return err; + + /* we're good, transfer the string now */ + err = transfer_string(it, bufferptr, offset, *len); + if (err) + return err; + + /* we've iterated at least once */ + it->flags &= ~CborIteratorFlag_BeforeFirstStringChunk; + return CborNoError; +} + +/** + * \fn CborError cbor_value_get_text_string_chunk(const CborValue *value, const char **bufferptr, size_t *len, CborValue *next) + * + * Extracts one text string chunk pointed to by \a value and stores a pointer + * to the data in \a buffer and the size in \a len, which must not be null. If + * no more chunks are available, then \a bufferptr will be set to null. This + * function may be used to iterate over any string without causing its contents + * to be copied to a separate buffer, like the convenience function + * cbor_value_copy_text_string() does. + * + * It is designed to be used in code like: + * + * \code + * if (cbor_value_is_text_string(value)) { + * char *ptr; + * size_t len; + * while (1) { + * err = cbor_value_get_text_string_chunk(value, &ptr, &len, &value)); + * if (err) return err; + * if (ptr == NULL) return CborNoError; + * consume(ptr, len); + * } + * } + * \endcode + * + * If the iterator \a value does not point to a text string, the behaviour is + * undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_text_string is recommended. + * + * The \a next pointer, if not null, will be updated to point to the next item + * after this string. During iteration, the pointer must only be passed back + * again to this function; passing it to any other function in this library + * results in undefined behavior. If there are no more chunks to be read from + * \a value, then \a next will be set to the next item after this string; if \a + * value points to the last item, then \a next will be invalid. + * + * \note This function does not perform UTF-8 validation on the incoming text + * string. + * + * \sa cbor_value_dup_text_string(), cbor_value_copy_text_string(), cbor_value_caculate_string_length(), cbor_value_get_byte_string_chunk() + */ + +/** + * \fn CborError cbor_value_get_byte_string_chunk(const CborValue *value, const char **bufferptr, size_t *len, CborValue *next) + * + * Extracts one byte string chunk pointed to by \a value and stores a pointer + * to the data in \a buffer and the size in \a len, which must not be null. If + * no more chunks are available, then \a bufferptr will be set to null. This + * function may be used to iterate over any string without causing its contents + * to be copied to a separate buffer, like the convenience function + * cbor_value_copy_byte_string() does. + * + * It is designed to be used in code like: + * + * \code + * if (cbor_value_is_byte_string(value)) { + * char *ptr; + * size_t len; + * while (1) { + * err = cbor_value_get_byte_string_chunk(value, &ptr, &len, &value)); + * if (err) return err; + * if (ptr == NULL) return CborNoError; + * consume(ptr, len); + * } + * } + * \endcode + * + * If the iterator \a value does not point to a byte string, the behaviour is + * undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_byte_string is recommended. + * + * The \a next pointer, if not null, will be updated to point to the next item + * after this string. During iteration, the pointer must only be passed back + * again to this function; passing it to any other function in this library + * results in undefined behavior. If there are no more chunks to be read from + * \a value, then \a next will be set to the next item after this string; if \a + * value points to the last item, then \a next will be invalid. + * + * \sa cbor_value_dup_byte_string(), cbor_value_copy_byte_string(), cbor_value_caculate_string_length(), cbor_value_get_text_string_chunk() + */ + +CborError _cbor_value_get_string_chunk(const CborValue *value, const void **bufferptr, + size_t *len, CborValue *next) +{ + CborValue tmp; + if (!next) + next = &tmp; + *next = *value; + return get_string_chunk(next, bufferptr, len); +} + +/* We return uintptr_t so that we can pass memcpy directly as the iteration + * function. The choice is to optimize for memcpy, which is used in the base + * parser API (cbor_value_copy_string), while memcmp is used in convenience API + * only. */ +typedef uintptr_t (*IterateFunction)(char *, const uint8_t *, size_t); + +static uintptr_t iterate_noop(char *dest, const uint8_t *src, size_t len) +{ + (void)dest; + (void)src; + (void)len; + return true; +} + +static uintptr_t iterate_memcmp(char *s1, const uint8_t *s2, size_t len) +{ + return memcmp(s1, (const char *)s2, len) == 0; +} + +static uintptr_t iterate_memcpy(char *dest, const uint8_t *src, size_t len) +{ + return (uintptr_t)memcpy(dest, src, len); +} + +static CborError iterate_string_chunks(const CborValue *value, char *buffer, size_t *buflen, + bool *result, CborValue *next, IterateFunction func) +{ + cbor_assert(cbor_value_is_byte_string(value) || cbor_value_is_text_string(value)); + + CborError err; + CborValue tmp; + size_t total = 0; + const void *ptr; + + if (!next) + next = &tmp; + *next = *value; + *result = true; + + err = _cbor_value_begin_string_iteration(next); + if (err) + return err; + + while (1) { + size_t newTotal; + size_t chunkLen; + err = get_string_chunk(next, &ptr, &chunkLen); + if (err == CborErrorNoMoreStringChunks) + break; + if (err) + return err; + + if (unlikely(add_check_overflow(total, chunkLen, &newTotal))) + return CborErrorDataTooLarge; + + if (*result && *buflen >= newTotal) + *result = !!func(buffer + total, (const uint8_t *)ptr, chunkLen); + else + *result = false; + + total = newTotal; + } + + /* is there enough room for the ending NUL byte? */ + if (*result && *buflen > total) { + uint8_t nul[] = { 0 }; + *result = !!func(buffer + total, nul, 1); + } + *buflen = total; + return _cbor_value_finish_string_iteration(next); +} + +/** + * \fn CborError cbor_value_copy_text_string(const CborValue *value, char *buffer, size_t *buflen, CborValue *next) + * + * Copies the string pointed to by \a value into the buffer provided at \a buffer + * of \a buflen bytes. If \a buffer is a NULL pointer, this function will not + * copy anything and will only update the \a next value. + * + * If the iterator \a value does not point to a text string, the behaviour is + * undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_text_string is recommended. + * + * If the provided buffer length was too small, this function returns an error + * condition of \ref CborErrorOutOfMemory. If you need to calculate the length + * of the string in order to preallocate a buffer, use + * cbor_value_calculate_string_length(). + * + * On success, this function sets the number of bytes copied to \c{*buflen}. If + * the buffer is large enough, this function will insert a null byte after the + * last copied byte, to facilitate manipulation of text strings. That byte is + * not included in the returned value of \c{*buflen}. If there was no space for + * the terminating null, no error is returned, so callers must check the value + * of *buflen after the call, before relying on the '\0'; if it has not been + * changed by the call, there is no '\0'-termination on the buffer's contents. + * + * The \a next pointer, if not null, will be updated to point to the next item + * after this string. If \a value points to the last item, then \a next will be + * invalid. + * + * This function may not run in constant time (it will run in O(n) time on the + * number of chunks). It requires constant memory (O(1)). + * + * \note This function does not perform UTF-8 validation on the incoming text + * string. + * + * \sa cbor_value_get_text_string_chunk() cbor_value_dup_text_string(), cbor_value_copy_byte_string(), cbor_value_get_string_length(), cbor_value_calculate_string_length() + */ + +/** + * \fn CborError cbor_value_copy_byte_string(const CborValue *value, uint8_t *buffer, size_t *buflen, CborValue *next) + * + * Copies the string pointed by \a value into the buffer provided at \a buffer + * of \a buflen bytes. If \a buffer is a NULL pointer, this function will not + * copy anything and will only update the \a next value. + * + * If the iterator \a value does not point to a byte string, the behaviour is + * undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_byte_string is recommended. + * + * If the provided buffer length was too small, this function returns an error + * condition of \ref CborErrorOutOfMemory. If you need to calculate the length + * of the string in order to preallocate a buffer, use + * cbor_value_calculate_string_length(). + * + * On success, this function sets the number of bytes copied to \c{*buflen}. If + * the buffer is large enough, this function will insert a null byte after the + * last copied byte, to facilitate manipulation of null-terminated strings. + * That byte is not included in the returned value of \c{*buflen}. + * + * The \a next pointer, if not null, will be updated to point to the next item + * after this string. If \a value points to the last item, then \a next will be + * invalid. + * + * This function may not run in constant time (it will run in O(n) time on the + * number of chunks). It requires constant memory (O(1)). + * + * \sa cbor_value_get_byte_string_chunk(), cbor_value_dup_text_string(), cbor_value_copy_text_string(), cbor_value_get_string_length(), cbor_value_calculate_string_length() + */ + +CborError _cbor_value_copy_string(const CborValue *value, void *buffer, + size_t *buflen, CborValue *next) +{ + bool copied_all; + CborError err = iterate_string_chunks(value, (char*)buffer, buflen, &copied_all, next, + buffer ? iterate_memcpy : iterate_noop); + return err ? err : + copied_all ? CborNoError : CborErrorOutOfMemory; +} + +/** + * Compares the entry \a value with the string \a string and stores the result + * in \a result. If the value is different from \a string \a result will + * contain \c false. + * + * The entry at \a value may be a tagged string. If \a value is not a string or + * a tagged string, the comparison result will be false. + * + * CBOR requires text strings to be encoded in UTF-8, but this function does + * not validate either the strings in the stream or the string \a string to be + * matched. Moreover, comparison is done on strict codepoint comparison, + * without any Unicode normalization. + * + * This function may not run in constant time (it will run in O(n) time on the + * number of chunks). It requires constant memory (O(1)). + * + * \sa cbor_value_skip_tag(), cbor_value_copy_text_string() + */ +CborError cbor_value_text_string_equals(const CborValue *value, const char *string, bool *result) +{ + CborValue copy = *value; + CborError err = cbor_value_skip_tag(©); + if (err) + return err; + if (!cbor_value_is_text_string(©)) { + *result = false; + return CborNoError; + } + + size_t len = strlen(string); + return iterate_string_chunks(©, CONST_CAST(char *, string), &len, result, NULL, iterate_memcmp); +} + +/** + * \fn bool cbor_value_is_array(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR array. + * + * \sa cbor_value_is_valid(), cbor_value_is_map() + */ + +/** + * \fn CborError cbor_value_get_array_length(const CborValue *value, size_t *length) + * + * Extracts the length of the CBOR array that \a value points to and stores it + * in \a result. If the iterator \a value does not point to a CBOR array, the + * behaviour is undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_array is recommended. + * + * If the length of this array is not encoded in the CBOR data stream, this + * function will return the recoverable error CborErrorUnknownLength. You may + * also check whether that is the case by using cbor_value_is_length_known(). + * + * \note On 32-bit platforms, this function will return error condition of \ref + * CborErrorDataTooLarge if the stream indicates a length that is too big to + * fit in 32-bit. + * + * \sa cbor_value_is_valid(), cbor_value_is_length_known() + */ + +/** + * \fn bool cbor_value_is_map(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR map. + * + * \sa cbor_value_is_valid(), cbor_value_is_array() + */ + +/** + * \fn CborError cbor_value_get_map_length(const CborValue *value, size_t *length) + * + * Extracts the length of the CBOR map that \a value points to and stores it in + * \a result. If the iterator \a value does not point to a CBOR map, the + * behaviour is undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_map is recommended. + * + * If the length of this map is not encoded in the CBOR data stream, this + * function will return the recoverable error CborErrorUnknownLength. You may + * also check whether that is the case by using cbor_value_is_length_known(). + * + * \note On 32-bit platforms, this function will return error condition of \ref + * CborErrorDataTooLarge if the stream indicates a length that is too big to + * fit in 32-bit. + * + * \sa cbor_value_is_valid(), cbor_value_is_length_known() + */ + +/** + * Attempts to find the value in map \a map that corresponds to the text string + * entry \a string. If the iterator \a value does not point to a CBOR map, the + * behaviour is undefined, so checking with \ref cbor_value_get_type or \ref + * cbor_value_is_map is recommended. + * + * If the item is found, it is stored in \a result. If no item is found + * matching the key, then \a result will contain an element of type \ref + * CborInvalidType. Matching is performed using + * cbor_value_text_string_equals(), so tagged strings will also match. + * + * This function has a time complexity of O(n) where n is the number of + * elements in the map to be searched. In addition, this function is has O(n) + * memory requirement based on the number of nested containers (maps or arrays) + * found as elements of this map. + * + * \sa cbor_value_is_valid(), cbor_value_text_string_equals(), cbor_value_advance() + */ +CborError cbor_value_map_find_value(const CborValue *map, const char *string, CborValue *element) +{ + cbor_assert(cbor_value_is_map(map)); + size_t len = strlen(string); + CborError err = cbor_value_enter_container(map, element); + if (err) + goto error; + + while (!cbor_value_at_end(element)) { + /* find the non-tag so we can compare */ + err = cbor_value_skip_tag(element); + if (err) + goto error; + if (cbor_value_is_text_string(element)) { + bool equals; + size_t dummyLen = len; + err = iterate_string_chunks(element, CONST_CAST(char *, string), &dummyLen, + &equals, element, iterate_memcmp); + if (err) + goto error; + if (equals) + return preparse_value(element); + } else { + /* skip this key */ + err = cbor_value_advance(element); + if (err) + goto error; + } + + /* skip this value */ + err = cbor_value_skip_tag(element); + if (err) + goto error; + err = cbor_value_advance(element); + if (err) + goto error; + } + + /* not found */ + element->type = CborInvalidType; + return CborNoError; + +error: + element->type = CborInvalidType; + return err; +} + +/** + * \fn bool cbor_value_is_float(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR + * single-precision floating point (32-bit). + * + * \sa cbor_value_is_valid(), cbor_value_is_double(), cbor_value_is_half_float() + */ + +/** + * \fn CborError cbor_value_get_float(const CborValue *value, float *result) + * + * Retrieves the CBOR single-precision floating point (32-bit) value that \a + * value points to and stores it in \a result. If the iterator \a value does + * not point to a single-precision floating point value, the behavior is + * undefined, so checking with \ref cbor_value_get_type or with \ref + * cbor_value_is_float is recommended. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_float(), cbor_value_get_double() + */ + +/** + * \fn bool cbor_value_is_double(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR + * double-precision floating point (64-bit). + * + * \sa cbor_value_is_valid(), cbor_value_is_float(), cbor_value_is_half_float() + */ + +/** + * \fn CborError cbor_value_get_double(const CborValue *value, float *result) + * + * Retrieves the CBOR double-precision floating point (64-bit) value that \a + * value points to and stores it in \a result. If the iterator \a value does + * not point to a double-precision floating point value, the behavior is + * undefined, so checking with \ref cbor_value_get_type or with \ref + * cbor_value_is_double is recommended. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_double(), cbor_value_get_float() + */ + +/** + * \fn bool cbor_value_is_half_float(const CborValue *value) + * + * Returns true if the iterator \a value is valid and points to a CBOR + * single-precision floating point (16-bit). + * + * \sa cbor_value_is_valid(), cbor_value_is_double(), cbor_value_is_float() + */ + +/** + * \fn CborError cbor_value_get_half_float(const CborValue *value, void *result) + * + * Retrieves the CBOR half-precision floating point (16-bit) value that \a + * value points to and stores it in \a result. If the iterator \a value does + * not point to a half-precision floating point value, the behavior is + * undefined, so checking with \ref cbor_value_get_type or with \ref + * cbor_value_is_half_float is recommended. + * + * Note: since the C language does not have a standard type for half-precision + * floating point, this function takes a \c{void *} as a parameter for the + * storage area, which must be at least 16 bits wide. + * + * \sa cbor_value_get_type(), cbor_value_is_valid(), cbor_value_is_half_float(), cbor_value_get_float() + */ + +/** @} */ |