Harald Welte | 468b643 | 2014-09-11 13:05:51 +0800 | [diff] [blame] | 1 | /* (C) 2008-2010 by Harald Welte <laforge@gnumonks.org> |
| 2 | * |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | * |
| 18 | */ |
| 19 | |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 20 | #include <stdio.h> |
| 21 | #include <stdint.h> |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 22 | #include <osmocom/core/utils.h> |
| 23 | #include <osmocom/gsm/tlv.h> |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 24 | |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 25 | /*! \addtogroup tlv |
| 26 | * @{ |
| 27 | */ |
Katerina Barone-Adesi | c28c6a0 | 2013-02-15 13:27:59 +0100 | [diff] [blame] | 28 | /*! \file tlv_parser.c */ |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 29 | |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 30 | struct tlv_definition tvlv_att_def; |
Harald Welte | 2fe6847 | 2012-07-14 01:50:33 +0200 | [diff] [blame] | 31 | struct tlv_definition vtvlv_gan_att_def; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 32 | |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 33 | /*! \brief Dump pasred TLV structure to stdout */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 34 | int tlv_dump(struct tlv_parsed *dec) |
| 35 | { |
| 36 | int i; |
| 37 | |
| 38 | for (i = 0; i <= 0xff; i++) { |
| 39 | if (!dec->lv[i].val) |
| 40 | continue; |
| 41 | printf("T=%02x L=%d\n", i, dec->lv[i].len); |
| 42 | } |
| 43 | return 0; |
| 44 | } |
| 45 | |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 46 | /*! \brief Parse a single TLV encoded IE |
| 47 | * \param[out] o_tag the tag of the IE that was found |
| 48 | * \param[out] o_len length of the IE that was found |
| 49 | * \param[out] o_val pointer to the data of the IE that was found |
| 50 | * \param[in] def structure defining the valid TLV tags / configurations |
| 51 | * \param[in] buf the input data buffer to be parsed |
| 52 | * \param[in] buf_len length of the input data buffer |
| 53 | * \returns number of bytes consumed by the TLV entry / IE parsed |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 54 | */ |
| 55 | int tlv_parse_one(uint8_t *o_tag, uint16_t *o_len, const uint8_t **o_val, |
| 56 | const struct tlv_definition *def, |
| 57 | const uint8_t *buf, int buf_len) |
| 58 | { |
| 59 | uint8_t tag; |
| 60 | int len; |
| 61 | |
| 62 | tag = *buf; |
| 63 | *o_tag = tag; |
| 64 | |
Andreas Eversberg | cd2a74b | 2010-07-12 08:55:14 +0200 | [diff] [blame] | 65 | /* single octet TV IE */ |
| 66 | if (def->def[tag & 0xf0].type == TLV_TYPE_SINGLE_TV) { |
| 67 | *o_tag = tag & 0xf0; |
| 68 | *o_val = buf; |
| 69 | *o_len = 1; |
| 70 | return 1; |
| 71 | } |
| 72 | |
Neels Hofmeyr | 667e83d | 2015-11-02 20:18:11 +0100 | [diff] [blame] | 73 | /* FIXME: use tables for known IEI */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 74 | switch (def->def[tag].type) { |
| 75 | case TLV_TYPE_T: |
| 76 | /* GSM TS 04.07 11.2.4: Type 1 TV or Type 2 T */ |
| 77 | *o_val = buf; |
| 78 | *o_len = 0; |
| 79 | len = 1; |
| 80 | break; |
| 81 | case TLV_TYPE_TV: |
| 82 | *o_val = buf+1; |
| 83 | *o_len = 1; |
| 84 | len = 2; |
| 85 | break; |
| 86 | case TLV_TYPE_FIXED: |
| 87 | *o_val = buf+1; |
| 88 | *o_len = def->def[tag].fixed_len; |
| 89 | len = def->def[tag].fixed_len + 1; |
| 90 | break; |
| 91 | case TLV_TYPE_TLV: |
Harald Welte | 2fe6847 | 2012-07-14 01:50:33 +0200 | [diff] [blame] | 92 | tlv: /* GSM TS 04.07 11.2.4: Type 4 TLV */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 93 | if (buf + 1 > buf + buf_len) |
| 94 | return -1; |
| 95 | *o_val = buf+2; |
| 96 | *o_len = *(buf+1); |
| 97 | len = *o_len + 2; |
| 98 | if (len > buf_len) |
| 99 | return -2; |
| 100 | break; |
Harald Welte | 2fe6847 | 2012-07-14 01:50:33 +0200 | [diff] [blame] | 101 | case TLV_TYPE_vTvLV_GAN: /* 44.318 / 11.1.4 */ |
| 102 | /* FIXME: variable-length TAG! */ |
| 103 | if (*(buf+1) & 0x80) { |
| 104 | /* like TL16Vbut without highest bit of len */ |
| 105 | if (2 > buf_len) |
| 106 | return -1; |
| 107 | *o_val = buf+3; |
| 108 | *o_len = (*(buf+1) & 0x7F) << 8 | *(buf+2); |
| 109 | len = *o_len + 3; |
| 110 | if (len > buf_len) |
| 111 | return -2; |
| 112 | } else { |
| 113 | /* like TLV */ |
| 114 | goto tlv; |
| 115 | } |
| 116 | break; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 117 | case TLV_TYPE_TvLV: |
| 118 | if (*(buf+1) & 0x80) { |
| 119 | /* like TLV, but without highest bit of len */ |
| 120 | if (buf + 1 > buf + buf_len) |
| 121 | return -1; |
| 122 | *o_val = buf+2; |
| 123 | *o_len = *(buf+1) & 0x7f; |
| 124 | len = *o_len + 2; |
| 125 | if (len > buf_len) |
| 126 | return -2; |
| 127 | break; |
| 128 | } |
| 129 | /* like TL16V, fallthrough */ |
| 130 | case TLV_TYPE_TL16V: |
| 131 | if (2 > buf_len) |
| 132 | return -1; |
| 133 | *o_val = buf+3; |
| 134 | *o_len = *(buf+1) << 8 | *(buf+2); |
| 135 | len = *o_len + 3; |
| 136 | if (len > buf_len) |
| 137 | return -2; |
| 138 | break; |
| 139 | default: |
| 140 | return -3; |
| 141 | } |
| 142 | |
| 143 | return len; |
| 144 | } |
| 145 | |
Neels Hofmeyr | 667e83d | 2015-11-02 20:18:11 +0100 | [diff] [blame] | 146 | /*! \brief Parse an entire buffer of TLV encoded Information Elements |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 147 | * \param[out] dec caller-allocated pointer to \ref tlv_parsed |
| 148 | * \param[in] def structure defining the valid TLV tags / configurations |
| 149 | * \param[in] buf the input data buffer to be parsed |
| 150 | * \param[in] buf_len length of the input data buffer |
| 151 | * \param[in] lv_tag an initial LV tag at the start of the buffer |
| 152 | * \param[in] lv_tag2 a second initial LV tag following the \a lv_tag |
| 153 | * \returns number of bytes consumed by the TLV entry / IE parsed |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 154 | */ |
| 155 | int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def, |
| 156 | const uint8_t *buf, int buf_len, uint8_t lv_tag, |
| 157 | uint8_t lv_tag2) |
| 158 | { |
| 159 | int ofs = 0, num_parsed = 0; |
| 160 | uint16_t len; |
| 161 | |
| 162 | memset(dec, 0, sizeof(*dec)); |
| 163 | |
| 164 | if (lv_tag) { |
| 165 | if (ofs > buf_len) |
| 166 | return -1; |
| 167 | dec->lv[lv_tag].val = &buf[ofs+1]; |
| 168 | dec->lv[lv_tag].len = buf[ofs]; |
| 169 | len = dec->lv[lv_tag].len + 1; |
| 170 | if (ofs + len > buf_len) |
| 171 | return -2; |
| 172 | num_parsed++; |
| 173 | ofs += len; |
| 174 | } |
| 175 | if (lv_tag2) { |
| 176 | if (ofs > buf_len) |
| 177 | return -1; |
| 178 | dec->lv[lv_tag2].val = &buf[ofs+1]; |
| 179 | dec->lv[lv_tag2].len = buf[ofs]; |
| 180 | len = dec->lv[lv_tag2].len + 1; |
| 181 | if (ofs + len > buf_len) |
| 182 | return -2; |
| 183 | num_parsed++; |
| 184 | ofs += len; |
| 185 | } |
| 186 | |
| 187 | while (ofs < buf_len) { |
| 188 | int rv; |
| 189 | uint8_t tag; |
| 190 | const uint8_t *val; |
| 191 | |
| 192 | rv = tlv_parse_one(&tag, &len, &val, def, |
| 193 | &buf[ofs], buf_len-ofs); |
| 194 | if (rv < 0) |
| 195 | return rv; |
| 196 | dec->lv[tag].val = val; |
| 197 | dec->lv[tag].len = len; |
| 198 | ofs += rv; |
| 199 | num_parsed++; |
| 200 | } |
| 201 | //tlv_dump(dec); |
| 202 | return num_parsed; |
| 203 | } |
| 204 | |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 205 | /*! \brief take a master (src) tlvdev and fill up all empty slots in 'dst' */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 206 | void tlv_def_patch(struct tlv_definition *dst, const struct tlv_definition *src) |
| 207 | { |
| 208 | int i; |
| 209 | |
| 210 | for (i = 0; i < ARRAY_SIZE(dst->def); i++) { |
| 211 | if (src->def[i].type == TLV_TYPE_NONE) |
| 212 | continue; |
| 213 | if (dst->def[i].type == TLV_TYPE_NONE) |
| 214 | dst->def[i] = src->def[i]; |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | static __attribute__((constructor)) void on_dso_load_tlv(void) |
| 219 | { |
| 220 | int i; |
| 221 | for (i = 0; i < ARRAY_SIZE(tvlv_att_def.def); i++) |
| 222 | tvlv_att_def.def[i].type = TLV_TYPE_TvLV; |
Harald Welte | 2fe6847 | 2012-07-14 01:50:33 +0200 | [diff] [blame] | 223 | |
| 224 | for (i = 0; i < ARRAY_SIZE(vtvlv_gan_att_def.def); i++) |
| 225 | vtvlv_gan_att_def.def[i].type = TLV_TYPE_vTvLV_GAN; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 226 | } |
Harald Welte | 57c7d37 | 2011-08-17 17:50:55 +0200 | [diff] [blame] | 227 | |
Harald Welte | fbd02fa | 2016-04-25 15:19:35 +0200 | [diff] [blame] | 228 | /*! Advance the data pointer, subtract length and assign value pointer |
| 229 | * \param data pointer to the pointer to data |
| 230 | * \param data_len pointer to size_t containing \arg data length |
| 231 | * \param[in] len the length that we expect the fixed IE to hav |
| 232 | * \param[out] value pointer to pointer of value part of IE |
| 233 | * \returns length of IE value; negative in case of error |
| 234 | */ |
| 235 | int osmo_shift_v_fixed(uint8_t **data, size_t *data_len, |
| 236 | size_t len, uint8_t **value) |
| 237 | { |
| 238 | if (len > *data_len) |
| 239 | goto fail; |
| 240 | |
| 241 | if (value) |
| 242 | *value = *data; |
| 243 | |
| 244 | *data += len; |
| 245 | *data_len -= len; |
| 246 | |
| 247 | return len; |
| 248 | |
| 249 | fail: |
| 250 | *data += *data_len; |
| 251 | *data_len = 0; |
| 252 | return -1; |
| 253 | } |
| 254 | |
| 255 | /*! Match tag, check length and assign value pointer |
| 256 | * \param data pointer to the pointer to data |
| 257 | * \param data_len pointer to size_t containing \arg data length |
| 258 | * \param[in] tag the tag (IEI) that we expect at \arg data |
| 259 | * \param[in] len the length that we expect the fixed IE to have |
| 260 | * \param[out] value pointer to pointer of value part of IE |
| 261 | * \returns length of IE value; negative in case of error |
| 262 | */ |
| 263 | int osmo_match_shift_tv_fixed(uint8_t **data, size_t *data_len, |
| 264 | uint8_t tag, size_t len, |
| 265 | uint8_t **value) |
| 266 | { |
| 267 | size_t ie_len; |
| 268 | |
| 269 | if (*data_len == 0) |
| 270 | goto fail; |
| 271 | |
| 272 | if ((*data)[0] != tag) |
| 273 | return 0; |
| 274 | |
| 275 | if (len > *data_len - 1) |
| 276 | goto fail; |
| 277 | |
| 278 | if (value) |
| 279 | *value = *data + 1; |
| 280 | |
| 281 | ie_len = len + 1; |
| 282 | *data += ie_len; |
| 283 | *data_len -= ie_len; |
| 284 | |
| 285 | return ie_len; |
| 286 | |
| 287 | fail: |
| 288 | *data += *data_len; |
| 289 | *data_len = 0; |
| 290 | return -1; |
| 291 | } |
| 292 | |
| 293 | /*! Verify TLV header and advance data / subtract length |
| 294 | * \param data pointer to the pointer to data |
| 295 | * \param data_len pointer to size_t containing \arg data length |
| 296 | * \param[in] expected_tag the tag (IEI) that we expect at \arg data |
| 297 | * \param[out] value pointer to pointer of value part of IE |
| 298 | * \param[out] value_len pointer to length of \arg value |
| 299 | * \returns length of IE value; negative in case of error |
| 300 | */ |
| 301 | int osmo_match_shift_tlv(uint8_t **data, size_t *data_len, |
| 302 | uint8_t expected_tag, uint8_t **value, |
| 303 | size_t *value_len) |
| 304 | { |
| 305 | int rc; |
| 306 | uint8_t tag; |
| 307 | uint8_t *old_data = *data; |
| 308 | size_t old_data_len = *data_len; |
| 309 | |
| 310 | rc = osmo_shift_tlv(data, data_len, &tag, value, value_len); |
| 311 | |
| 312 | if (rc > 0 && tag != expected_tag) { |
| 313 | *data = old_data; |
| 314 | *data_len = old_data_len; |
| 315 | return 0; |
| 316 | } |
| 317 | |
| 318 | return rc; |
| 319 | } |
| 320 | |
| 321 | /*! Extract TLV and advance data pointer + subtract length |
| 322 | * \param data pointer to the pointer to data |
| 323 | * \param data_len pointer to size_t containing \arg data lengt |
| 324 | * \param[out] tag extract the tag (IEI) at start of \arg data |
| 325 | * \param[out] value extracted pointer to value part of TLV |
| 326 | * \param[out] value_len extracted length of \arg value |
| 327 | * \returns number of bytes subtracted |
| 328 | */ |
| 329 | int osmo_shift_tlv(uint8_t **data, size_t *data_len, |
| 330 | uint8_t *tag, uint8_t **value, size_t *value_len) |
| 331 | { |
| 332 | size_t len; |
| 333 | size_t ie_len; |
| 334 | |
| 335 | if (*data_len < 2) |
| 336 | goto fail; |
| 337 | |
| 338 | len = (*data)[1]; |
| 339 | if (len > *data_len - 2) |
| 340 | goto fail; |
| 341 | |
| 342 | if (tag) |
| 343 | *tag = (*data)[0]; |
| 344 | if (value) |
| 345 | *value = *data + 2; |
| 346 | if (value_len) |
| 347 | *value_len = len; |
| 348 | |
| 349 | ie_len = len + 2; |
| 350 | |
| 351 | *data += ie_len; |
| 352 | *data_len -= ie_len; |
| 353 | |
| 354 | return ie_len; |
| 355 | |
| 356 | fail: |
| 357 | *data += *data_len; |
| 358 | *data_len = 0; |
| 359 | return -1; |
| 360 | } |
| 361 | |
| 362 | /*! Extract LV and advance data pointer + subtract length |
| 363 | * \param data pointer to the pointer to data |
| 364 | * \param data_len pointer to size_t containing \arg data lengt |
| 365 | * \param[out] value extracted pointer to value part of TLV |
| 366 | * \param[out] value_len extracted length of \arg value |
| 367 | * \returns number of bytes subtracted |
| 368 | */ |
| 369 | int osmo_shift_lv(uint8_t **data, size_t *data_len, |
| 370 | uint8_t **value, size_t *value_len) |
| 371 | { |
| 372 | size_t len; |
| 373 | size_t ie_len; |
| 374 | |
| 375 | if (*data_len < 1) |
| 376 | goto fail; |
| 377 | |
| 378 | len = (*data)[0]; |
| 379 | if (len > *data_len - 1) |
| 380 | goto fail; |
| 381 | |
| 382 | if (value) |
| 383 | *value = *data + 1; |
| 384 | if (value_len) |
| 385 | *value_len = len; |
| 386 | |
| 387 | ie_len = len + 1; |
| 388 | *data += ie_len; |
| 389 | *data_len -= ie_len; |
| 390 | |
| 391 | return ie_len; |
| 392 | |
| 393 | fail: |
| 394 | *data += *data_len; |
| 395 | *data_len = 0; |
| 396 | return -1; |
| 397 | } |
| 398 | |
Sylvain Munaut | dca7d2c | 2012-04-18 21:53:23 +0200 | [diff] [blame] | 399 | /*! @} */ |