1/****************************************************************************
2**
3** Copyright (C) 2018 Intel Corporation
4**
5** Permission is hereby granted, free of charge, to any person obtaining a copy
6** of this software and associated documentation files (the "Software"), to deal
7** in the Software without restriction, including without limitation the rights
8** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9** copies of the Software, and to permit persons to whom the Software is
10** furnished to do so, subject to the following conditions:
11**
12** The above copyright notice and this permission notice shall be included in
13** all copies or substantial portions of the Software.
14**
15** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21** THE SOFTWARE.
22**
23****************************************************************************/
24
25#ifndef CBORINTERNAL_P_H
26#define CBORINTERNAL_P_H
27
28#include "compilersupport_p.h"
29
30#ifndef CBOR_NO_FLOATING_POINT
31# include <float.h>
32# include <math.h>
33#else
34# ifndef CBOR_NO_HALF_FLOAT_TYPE
35# define CBOR_NO_HALF_FLOAT_TYPE 1
36# endif
37#endif
38
39#ifndef CBOR_NO_HALF_FLOAT_TYPE
40# ifdef __F16C__
41# include <immintrin.h>
42static inline unsigned short encode_half(double val)
43{
44 return _cvtss_sh((float)val, 3);
45}
46static inline double decode_half(unsigned short half)
47{
48 return _cvtsh_ss(half);
49}
50# else
51/* software implementation of float-to-fp16 conversions */
52static inline unsigned short encode_half(double val)
53{
54 uint64_t v;
55 int sign, exp, mant;
56 memcpy(&v, &val, sizeof(v));
57 sign = v >> 63 << 15;
58 exp = (v >> 52) & 0x7ff;
59 mant = v << 12 >> 12 >> (53-11); /* keep only the 11 most significant bits of the mantissa */
60 exp -= 1023;
61 if (exp == 1024) {
62 /* infinity or NaN */
63 exp = 16;
64 mant >>= 1;
65 } else if (exp >= 16) {
66 /* overflow, as largest number */
67 exp = 15;
68 mant = 1023;
69 } else if (exp >= -14) {
70 /* regular normal */
71 } else if (exp >= -24) {
72 /* subnormal */
73 mant |= 1024;
74 mant >>= -(exp + 14);
75 exp = -15;
76 } else {
77 /* underflow, make zero */
78 return 0;
79 }
80
81 /* safe cast here as bit operations above guarantee not to overflow */
82 return (unsigned short)(sign | ((exp + 15) << 10) | mant);
83}
84
85/* this function was copied & adapted from RFC 7049 Appendix D */
86static inline double decode_half(unsigned short half)
87{
88 int exp = (half >> 10) & 0x1f;
89 int mant = half & 0x3ff;
90 double val;
91 if (exp == 0) val = ldexp(mant, -24);
92 else if (exp != 31) val = ldexp(mant + 1024, exp - 25);
93 else val = mant == 0 ? INFINITY : NAN;
94 return half & 0x8000 ? -val : val;
95}
96# endif
97#endif /* CBOR_NO_HALF_FLOAT_TYPE */
98
99#ifndef CBOR_INTERNAL_API
100# define CBOR_INTERNAL_API
101#endif
102
103#ifndef CBOR_PARSER_MAX_RECURSIONS
104# define CBOR_PARSER_MAX_RECURSIONS 1024
105#endif
106
107#ifndef CBOR_ENCODER_WRITER_CONTROL
108# define CBOR_ENCODER_WRITER_CONTROL 0
109#endif
110#ifndef CBOR_PARSER_READER_CONTROL
111# define CBOR_PARSER_READER_CONTROL 0
112#endif
113
114/*
115 * CBOR Major types
116 * Encoded in the high 3 bits of the descriptor byte
117 * See http://tools.ietf.org/html/rfc7049#section-2.1
118 */
119typedef enum CborMajorTypes {
120 UnsignedIntegerType = 0U,
121 NegativeIntegerType = 1U,
122 ByteStringType = 2U,
123 TextStringType = 3U,
124 ArrayType = 4U,
125 MapType = 5U, /* a.k.a. object */
126 TagType = 6U,
127 SimpleTypesType = 7U
128} CborMajorTypes;
129
130/*
131 * CBOR simple and floating point types
132 * Encoded in the low 8 bits of the descriptor byte when the
133 * Major Type is 7.
134 */
135typedef enum CborSimpleTypes {
136 FalseValue = 20,
137 TrueValue = 21,
138 NullValue = 22,
139 UndefinedValue = 23,
140 SimpleTypeInNextByte = 24, /* not really a simple type */
141 HalfPrecisionFloat = 25, /* ditto */
142 SinglePrecisionFloat = 26, /* ditto */
143 DoublePrecisionFloat = 27, /* ditto */
144 Break = 31
145} CborSimpleTypes;
146
147enum {
148 SmallValueBitLength = 5U,
149 SmallValueMask = (1U << SmallValueBitLength) - 1, /* 31 */
150 Value8Bit = 24U,
151 Value16Bit = 25U,
152 Value32Bit = 26U,
153 Value64Bit = 27U,
154 IndefiniteLength = 31U,
155
156 MajorTypeShift = SmallValueBitLength,
157 MajorTypeMask = (int) (~0U << MajorTypeShift),
158
159 BreakByte = (unsigned)Break | (SimpleTypesType << MajorTypeShift)
160};
161
162static inline void copy_current_position(CborValue *dst, const CborValue *src)
163{
164 /* This "if" is here for pedantry only: the two branches should perform
165 * the same memory operation. */
166 if (src->parser->flags & CborParserFlag_ExternalSource)
167 dst->source.token = src->source.token;
168 else
169 dst->source.ptr = src->source.ptr;
170}
171
172static inline bool can_read_bytes(const CborValue *it, size_t n)
173{
174 if (CBOR_PARSER_READER_CONTROL >= 0) {
175 if (it->parser->flags & CborParserFlag_ExternalSource || CBOR_PARSER_READER_CONTROL != 0) {
176#ifdef CBOR_PARSER_CAN_READ_BYTES_FUNCTION
177 return CBOR_PARSER_CAN_READ_BYTES_FUNCTION(it->source.token, n);
178#else
179 return it->parser->source.ops->can_read_bytes(it->source.token, n);
180#endif
181 }
182 }
183
184 /* Convert the pointer subtraction to size_t since end >= ptr
185 * (this prevents issues with (ptrdiff_t)n becoming negative).
186 */
187 return (size_t)(it->parser->source.end - it->source.ptr) >= n;
188}
189
190static inline void advance_bytes(CborValue *it, size_t n)
191{
192 if (CBOR_PARSER_READER_CONTROL >= 0) {
193 if (it->parser->flags & CborParserFlag_ExternalSource || CBOR_PARSER_READER_CONTROL != 0) {
194#ifdef CBOR_PARSER_ADVANCE_BYTES_FUNCTION
195 CBOR_PARSER_ADVANCE_BYTES_FUNCTION(it->source.token, n);
196#else
197 it->parser->source.ops->advance_bytes(it->source.token, n);
198#endif
199 return;
200 }
201 }
202
203 it->source.ptr += n;
204}
205
206static inline CborError transfer_string(CborValue *it, const void **ptr, size_t offset, size_t len)
207{
208 if (CBOR_PARSER_READER_CONTROL >= 0) {
209 if (it->parser->flags & CborParserFlag_ExternalSource || CBOR_PARSER_READER_CONTROL != 0) {
210#ifdef CBOR_PARSER_TRANSFER_STRING_FUNCTION
211 return CBOR_PARSER_TRANSFER_STRING_FUNCTION(it->source.token, ptr, offset, len);
212#else
213 return it->parser->source.ops->transfer_string(it->source.token, ptr, offset, len);
214#endif
215 }
216 }
217
218 it->source.ptr += offset;
219 if (can_read_bytes(it, len)) {
220 *CONST_CAST(const void **, ptr) = it->source.ptr;
221 it->source.ptr += len;
222 return CborNoError;
223 }
224 return CborErrorUnexpectedEOF;
225}
226
227static inline void *read_bytes_unchecked(const CborValue *it, void *dst, size_t offset, size_t n)
228{
229 if (CBOR_PARSER_READER_CONTROL >= 0) {
230 if (it->parser->flags & CborParserFlag_ExternalSource || CBOR_PARSER_READER_CONTROL != 0) {
231#ifdef CBOR_PARSER_READ_BYTES_FUNCTION
232 return CBOR_PARSER_READ_BYTES_FUNCTION(it->source.token, dst, offset, n);
233#else
234 return it->parser->source.ops->read_bytes(it->source.token, dst, offset, n);
235#endif
236 }
237 }
238
239 return memcpy(dst, it->source.ptr + offset, n);
240}
241
242#ifdef __GNUC__
243__attribute__((warn_unused_result))
244#endif
245static inline void *read_bytes(const CborValue *it, void *dst, size_t offset, size_t n)
246{
247 if (can_read_bytes(it, offset + n))
248 return read_bytes_unchecked(it, dst, offset, n);
249 return NULL;
250}
251
252static inline uint16_t read_uint8(const CborValue *it, size_t offset)
253{
254 uint8_t result;
255 read_bytes_unchecked(it, &result, offset, sizeof(result));
256 return result;
257}
258
259static inline uint16_t read_uint16(const CborValue *it, size_t offset)
260{
261 uint16_t result;
262 read_bytes_unchecked(it, &result, offset, sizeof(result));
263 return cbor_ntohs(result);
264}
265
266static inline uint32_t read_uint32(const CborValue *it, size_t offset)
267{
268 uint32_t result;
269 read_bytes_unchecked(it, &result, offset, sizeof(result));
270 return cbor_ntohl(result);
271}
272
273static inline uint64_t read_uint64(const CborValue *it, size_t offset)
274{
275 uint64_t result;
276 read_bytes_unchecked(it, &result, offset, sizeof(result));
277 return cbor_ntohll(result);
278}
279
280static inline CborError extract_number_checked(const CborValue *it, uint64_t *value, size_t *bytesUsed)
281{
282 uint8_t descriptor;
283 size_t bytesNeeded = 0;
284
285 /* We've already verified that there's at least one byte to be read */
286 read_bytes_unchecked(it, &descriptor, 0, 1);
287 descriptor &= SmallValueMask;
288 if (descriptor < Value8Bit) {
289 *value = descriptor;
290 } else if (unlikely(descriptor > Value64Bit)) {
291 return CborErrorIllegalNumber;
292 } else {
293 bytesNeeded = (size_t)(1 << (descriptor - Value8Bit));
294 if (!can_read_bytes(it, 1 + bytesNeeded))
295 return CborErrorUnexpectedEOF;
296 if (descriptor <= Value16Bit) {
297 if (descriptor == Value16Bit)
298 *value = read_uint16(it, 1);
299 else
300 *value = read_uint8(it, 1);
301 } else {
302 if (descriptor == Value32Bit)
303 *value = read_uint32(it, 1);
304 else
305 *value = read_uint64(it, 1);
306 }
307 }
308
309 if (bytesUsed)
310 *bytesUsed = bytesNeeded;
311 return CborNoError;
312}
313
314#endif /* CBORINTERNAL_P_H */
315