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/****************************************************************************
**
** Copyright (C) 2016 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.
**
****************************************************************************/
#define _BSD_SOURCE 1
#define _DEFAULT_SOURCE 1
#ifndef __STDC_LIMIT_MACROS
# define __STDC_LIMIT_MACROS 1
#endif
#include "cbor.h"
#include "compilersupport_p.h"
#include "math_support_p.h"
#include <float.h>
#include <inttypes.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/**
* \defgroup CborPretty Converting CBOR to text
* \brief Group of functions used to convert CBOR to text form.
*
* This group contains two functions that are can be used to convert one
* CborValue object to a text representation. This module attempts to follow
* the recommendations from RFC 7049 section 6 "Diagnostic Notation", though it
* has a few differences. They are noted below.
*
* TinyCBOR does not provide a way to convert from the text representation back
* to encoded form. To produce a text form meant to be parsed, CborToJson is
* recommended instead.
*
* Either of the functions in this section will attempt to convert exactly one
* CborValue object to text. Those functions may return any error documented
* for the functions for CborParsing. In addition, if the C standard library
* stream functions return with error, the text conversion will return with
* error CborErrorIO.
*
* These functions also perform UTF-8 validation in CBOR text strings. If they
* encounter a sequence of bytes that not permitted in UTF-8, they will return
* CborErrorInvalidUtf8TextString. That includes encoding of surrogate points
* in UTF-8.
*
* \warning The output type produced by these functions is not guaranteed to
* remain stable. A future update of TinyCBOR may produce different output for
* the same input and parsers may be unable to handle them.
*
* \sa CborParsing, CborToJson, cbor_parser_init()
*/
/**
* \addtogroup CborPretty
* @{
* <h2 class="groupheader">Text format</h2>
*
* As described in RFC 7049 section 6 "Diagnostic Notation", the format is
* largely borrowed from JSON, but modified to suit CBOR's different data
* types. TinyCBOR makes further modifications to distinguish different, but
* similar values.
*
* CBOR values are currently encoded as follows:
* \par Integrals (unsigned and negative)
* Base-10 (decimal) text representation of the value
* \par Byte strings:
* <tt>"h'"</tt> followed by the Base16 (hex) representation of the binary data, followed by an ending quote (')
* \par Text strings:
* C-style escaped string in quotes, with C11/C++11 escaping of Unicode codepoints above U+007F.
* \par Tags:
* Tag value, with the tagged value in parentheses. No special encoding of the tagged value is performed.
* \par Simple types:
* <tt>"simple(nn)"</tt> where \c nn is the simple value
* \par Null:
* \c null
* \par Undefined:
* \c undefined
* \par Booleans:
* \c true or \c false
* \par Floating point:
* If NaN or infinite, the actual words \c NaN or \c infinite.
* Otherwise, the decimal representation with as many digits as necessary to ensure no loss of information,
* with float values suffixed by "f" and half-float values suffixed by "f16" (doubles have no suffix). A dot is always present.
* \par Arrays:
* Comma-separated list of elements, enclosed in square brackets ("[" and "]").
* If the array length is indeterminate, an underscore ("_") appears immediately after the opening bracket.
* \par Maps:
* Comma-separated list of key-value pairs, with the key and value separated
* by a colon (":"), enclosed in curly braces ("{" and "}").
* If the map length is indeterminate, an underscore ("_") appears immediately after the opening brace.
*/
static int hexDump(FILE *out, const uint8_t *buffer, size_t n)
{
while (n--) {
int r = fprintf(out, "%02" PRIx8, *buffer++);
if (r < 0)
return r;
}
return 0; /* should be n * 2, but we don't have the original n anymore */
}
/* This function decodes buffer as UTF-8 and prints as escaped UTF-16.
* On UTF-8 decoding error, it returns CborErrorInvalidUtf8TextString */
static int utf8EscapedDump(FILE *out, const char *buffer, size_t n)
{
uint32_t uc;
while (n--) {
uc = (uint8_t)*buffer++;
if (uc < 0x80) {
/* single-byte UTF-8 */
if (uc < 0x7f && uc >= 0x20 && uc != '\\' && uc != '"') {
if (fprintf(out, "%c", (char)uc) < 0)
return CborErrorIO;
continue;
}
/* print as an escape sequence */
char escaped = (char)uc;
switch (uc) {
case '"':
case '\\':
break;
case '\b':
escaped = 'b';
break;
case '\f':
escaped = 'f';
break;
case '\n':
escaped = 'n';
break;
case '\r':
escaped = 'r';
break;
case '\t':
escaped = 't';
break;
default:
goto print_utf16;
}
if (fprintf(out, "\\%c", escaped) < 0)
return CborErrorIO;
continue;
}
/* multi-byte UTF-8, decode it */
unsigned charsNeeded;
uint32_t min_uc;
if (unlikely(uc <= 0xC1))
return CborErrorInvalidUtf8TextString;
if (uc < 0xE0) {
/* two-byte UTF-8 */
charsNeeded = 2;
min_uc = 0x80;
uc &= 0x1f;
} else if (uc < 0xF0) {
/* three-byte UTF-8 */
charsNeeded = 3;
min_uc = 0x800;
uc &= 0x0f;
} else if (uc < 0xF5) {
/* four-byte UTF-8 */
charsNeeded = 4;
min_uc = 0x10000;
uc &= 0x07;
} else {
return CborErrorInvalidUtf8TextString;
}
if (n < charsNeeded - 1)
return CborErrorInvalidUtf8TextString;
n -= charsNeeded - 1;
/* first continuation character */
uint8_t b = (uint8_t)*buffer++;
if ((b & 0xc0) != 0x80)
return CborErrorInvalidUtf8TextString;
uc <<= 6;
uc |= b & 0x3f;
if (charsNeeded > 2) {
/* second continuation character */
b = (uint8_t)*buffer++;
if ((b & 0xc0) != 0x80)
return CborErrorInvalidUtf8TextString;
uc <<= 6;
uc |= b & 0x3f;
if (charsNeeded > 3) {
/* third continuation character */
b = (uint8_t)*buffer++;
if ((b & 0xc0) != 0x80)
return CborErrorInvalidUtf8TextString;
uc <<= 6;
uc |= b & 0x3f;
}
}
/* overlong sequence? surrogate pair? out or range? */
if (uc < min_uc || uc - 0xd800U < 2048U || uc > 0x10ffff)
return CborErrorInvalidUtf8TextString;
/* now print the sequence */
if (charsNeeded > 3) {
/* needs surrogate pairs */
if (fprintf(out, "\\u%04" PRIX32 "\\u%04" PRIX32,
(uc >> 10) + 0xd7c0, /* high surrogate */
(uc % 0x0400) + 0xdc00) < 0)
return CborErrorIO;
} else {
print_utf16:
/* no surrogate pair needed */
if (fprintf(out, "\\u%04" PRIX32, uc) < 0)
return CborErrorIO;
}
}
return CborNoError;
}
static CborError value_to_pretty(FILE *out, CborValue *it);
static CborError container_to_pretty(FILE *out, CborValue *it, CborType containerType)
{
const char *comma = "";
while (!cbor_value_at_end(it)) {
if (fprintf(out, "%s", comma) < 0)
return CborErrorIO;
comma = ", ";
CborError err = value_to_pretty(out, it);
if (err)
return err;
if (containerType == CborArrayType)
continue;
/* map: that was the key, so get the value */
if (fprintf(out, ": ") < 0)
return CborErrorIO;
err = value_to_pretty(out, it);
if (err)
return err;
}
return CborNoError;
}
static CborError value_to_pretty(FILE *out, CborValue *it)
{
CborError err;
CborType type = cbor_value_get_type(it);
switch (type) {
case CborArrayType:
case CborMapType: {
/* recursive type */
CborValue recursed;
if (fprintf(out, type == CborArrayType ? "[" : "{") < 0)
return CborErrorIO;
if (!cbor_value_is_length_known(it)) {
if (fprintf(out, "_ ") < 0)
return CborErrorIO;
}
err = cbor_value_enter_container(it, &recursed);
if (err) {
it->ptr = recursed.ptr;
return err; /* parse error */
}
err = container_to_pretty(out, &recursed, type);
if (err) {
it->ptr = recursed.ptr;
return err; /* parse error */
}
err = cbor_value_leave_container(it, &recursed);
if (err)
return err; /* parse error */
if (fprintf(out, type == CborArrayType ? "]" : "}") < 0)
return CborErrorIO;
return CborNoError;
}
case CborIntegerType: {
uint64_t val;
cbor_value_get_raw_integer(it, &val); /* can't fail */
if (cbor_value_is_unsigned_integer(it)) {
if (fprintf(out, "%" PRIu64, val) < 0)
return CborErrorIO;
} else {
/* CBOR stores the negative number X as -1 - X
* (that is, -1 is stored as 0, -2 as 1 and so forth) */
if (++val) { /* unsigned overflow may happen */
if (fprintf(out, "-%" PRIu64, val) < 0)
return CborErrorIO;
} else {
/* overflown
* 0xffff`ffff`ffff`ffff + 1 =
* 0x1`0000`0000`0000`0000 = 18446744073709551616 (2^64) */
if (fprintf(out, "-18446744073709551616") < 0)
return CborErrorIO;
}
}
break;
}
case CborByteStringType:{
size_t n = 0;
uint8_t *buffer;
err = cbor_value_dup_byte_string(it, &buffer, &n, it);
if (err)
return err;
bool failed = fprintf(out, "h'") < 0 || hexDump(out, buffer, n) < 0 || fprintf(out, "'") < 0;
free(buffer);
return failed ? CborErrorIO : CborNoError;
}
case CborTextStringType: {
size_t n = 0;
char *buffer;
err = cbor_value_dup_text_string(it, &buffer, &n, it);
if (err)
return err;
err = CborNoError;
bool failed = fprintf(out, "\"") < 0
|| (err = utf8EscapedDump(out, buffer, n)) != CborNoError
|| fprintf(out, "\"") < 0;
free(buffer);
return err != CborNoError ? err :
failed ? CborErrorIO : CborNoError;
}
case CborTagType: {
CborTag tag;
cbor_value_get_tag(it, &tag); /* can't fail */
if (fprintf(out, "%" PRIu64 "(", tag) < 0)
return CborErrorIO;
err = cbor_value_advance_fixed(it);
if (err)
return err;
err = value_to_pretty(out, it);
if (err)
return err;
if (fprintf(out, ")") < 0)
return CborErrorIO;
return CborNoError;
}
case CborSimpleType: {
uint8_t simple_type;
cbor_value_get_simple_type(it, &simple_type); /* can't fail */
if (fprintf(out, "simple(%" PRIu8 ")", simple_type) < 0)
return CborErrorIO;
break;
}
case CborNullType:
if (fprintf(out, "null") < 0)
return CborErrorIO;
break;
case CborUndefinedType:
if (fprintf(out, "undefined") < 0)
return CborErrorIO;
break;
case CborBooleanType: {
bool val;
cbor_value_get_boolean(it, &val); /* can't fail */
if (fprintf(out, val ? "true" : "false") < 0)
return CborErrorIO;
break;
}
case CborDoubleType: {
const char *suffix;
double val;
if (false) {
float f;
case CborFloatType:
cbor_value_get_float(it, &f);
val = f;
suffix = "f";
} else if (false) {
uint16_t f16;
case CborHalfFloatType:
cbor_value_get_half_float(it, &f16);
val = decode_half(f16);
suffix = "f16";
} else {
cbor_value_get_double(it, &val);
suffix = "";
}
int r = fpclassify(val);
if (r == FP_NAN || r == FP_INFINITE)
suffix = "";
uint64_t ival = (uint64_t)fabs(val);
if (ival == fabs(val)) {
/* this double value fits in a 64-bit integer, so show it as such
* (followed by a floating point suffix, to disambiguate) */
r = fprintf(out, "%s%" PRIu64 ".%s", val < 0 ? "-" : "", ival, suffix);
} else {
/* this number is definitely not a 64-bit integer */
r = fprintf(out, "%." DBL_DECIMAL_DIG_STR "g%s", val, suffix);
}
if (r < 0)
return CborErrorIO;
break;
}
case CborInvalidType:
if (fprintf(out, "invalid") < 0)
return CborErrorIO;
return CborErrorUnknownType;
}
err = cbor_value_advance_fixed(it);
return err;
}
/**
* \fn CborError cbor_value_to_pretty(FILE *out, const CborValue *value)
*
* Converts the current CBOR type pointed by \a value to its textual
* representation and writes it to the \a out stream. If an error occurs, this
* function returns an error code similar to CborParsing.
*
* \sa cbor_value_to_pretty_advance(), cbor_value_to_json_advance()
*/
/**
* Converts the current CBOR type pointed by \a value to its textual
* representation and writes it to the \a out stream. If an error occurs, this
* function returns an error code similar to CborParsing.
*
* If no error ocurred, this function advances \a value to the next element.
* Often, concatenating the text representation of multiple elements can be
* done by appending a comma to the output stream.
*
* \sa cbor_value_to_pretty(), cbor_value_to_json_advance()
*/
CborError cbor_value_to_pretty_advance(FILE *out, CborValue *value)
{
return value_to_pretty(out, value);
}
/** @} */