Neels Hofmeyr | 17518fe | 2017-06-20 04:35:06 +0200 | [diff] [blame] | 1 | /*! \file gsm0480.c |
| 2 | * Format functions for GSM 04.80. */ |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 3 | /* |
| 4 | * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> |
| 5 | * (C) 2009 by Mike Haben <michael.haben@btinternet.com> |
Harald Welte | b1a35d6 | 2018-06-16 18:34:52 +0200 | [diff] [blame] | 6 | * (C) 2018 by Harald Welte <laforge@gnumonks.org> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 7 | * |
| 8 | * All Rights Reserved |
| 9 | * |
Harald Welte | e08da97 | 2017-11-13 01:00:26 +0900 | [diff] [blame] | 10 | * SPDX-License-Identifier: GPL-2.0+ |
| 11 | * |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License along |
| 23 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 24 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 25 | * |
| 26 | */ |
| 27 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 28 | #include <osmocom/gsm/gsm0480.h> |
| 29 | #include <osmocom/gsm/gsm_utils.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 30 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 31 | #include <osmocom/core/logging.h> |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 32 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 33 | #include <osmocom/gsm/protocol/gsm_04_08.h> |
| 34 | #include <osmocom/gsm/protocol/gsm_04_80.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 35 | |
| 36 | #include <string.h> |
Vadim Yanitskiy | 52e4412 | 2018-06-11 03:51:11 +0700 | [diff] [blame] | 37 | #include <errno.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 38 | |
Harald Welte | b1a35d6 | 2018-06-16 18:34:52 +0200 | [diff] [blame] | 39 | const struct value_string gsm0480_comp_type_names[] = { |
| 40 | { GSM0480_CTYPE_INVOKE, "Invoke" }, |
| 41 | { GSM0480_CTYPE_RETURN_RESULT, "ReturnResult" }, |
| 42 | { GSM0480_CTYPE_RETURN_ERROR, "ReturnError" }, |
| 43 | { GSM0480_CTYPE_REJECT, "Reject" }, |
| 44 | { 0, NULL } |
| 45 | }; |
| 46 | |
| 47 | const struct value_string gsm0480_op_code_names[] = { |
| 48 | { GSM0480_OP_CODE_REGISTER_SS, "RegisterSS" }, |
| 49 | { GSM0480_OP_CODE_ERASE_SS, "EraseSS" }, |
| 50 | { GSM0480_OP_CODE_ACTIVATE_SS, "ActivateSS" }, |
| 51 | { GSM0480_OP_CODE_DEACTIVATE_SS, "DeactivateSS" }, |
| 52 | { GSM0480_OP_CODE_INTERROGATE_SS, "IngerrogateSS" }, |
| 53 | { GSM0480_OP_CODE_NOTIFY_SS, "NotifySS" }, |
| 54 | { GSM0480_OP_CODE_REGISTER_PASSWORD, "RegisterPassword" }, |
| 55 | { GSM0480_OP_CODE_GET_PASSWORD, "GetPassword" }, |
| 56 | { GSM0480_OP_CODE_PROCESS_USS_DATA, "ProcessUSSD" }, |
| 57 | { GSM0480_OP_CODE_FORWARD_CHECK_SS_IND, "ForwardChecckSSind" }, |
| 58 | { GSM0480_OP_CODE_PROCESS_USS_REQ, "ProcessUssReq" }, |
| 59 | { GSM0480_OP_CODE_USS_REQUEST, "UssRequest" }, |
| 60 | { GSM0480_OP_CODE_USS_NOTIFY, "UssNotify" }, |
| 61 | { GSM0480_OP_CODE_FORWARD_CUG_INFO, "ForwardCugInfo" }, |
| 62 | { GSM0480_OP_CODE_SPLIT_MPTY, "SplitMPTY" }, |
| 63 | { GSM0480_OP_CODE_RETRIEVE_MPTY, "RetrieveMPTY" }, |
| 64 | { GSM0480_OP_CODE_HOLD_MPTY, "HoldMPTY" }, |
| 65 | { GSM0480_OP_CODE_BUILD_MPTY, "BuildMPTY" }, |
| 66 | { GSM0480_OP_CODE_FORWARD_CHARGE_ADVICE, "ForwardChargeAdvice" }, |
| 67 | { 0, NULL } |
| 68 | }; |
| 69 | |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 70 | static inline unsigned char *msgb_wrap_with_TL(struct msgb *msgb, uint8_t tag) |
| 71 | { |
| 72 | uint8_t *data = msgb_push(msgb, 2); |
| 73 | |
| 74 | data[0] = tag; |
| 75 | data[1] = msgb->len - 2; |
| 76 | return data; |
| 77 | } |
| 78 | |
| 79 | static inline unsigned char *msgb_push_TLV1(struct msgb *msgb, uint8_t tag, |
| 80 | uint8_t value) |
| 81 | { |
| 82 | uint8_t *data = msgb_push(msgb, 3); |
| 83 | |
| 84 | data[0] = tag; |
| 85 | data[1] = 1; |
| 86 | data[2] = value; |
| 87 | return data; |
| 88 | } |
| 89 | |
Harald Welte | 7ecc4a3 | 2018-07-28 23:05:36 +0200 | [diff] [blame] | 90 | static inline unsigned char *msgb_push_NULL(struct msgb *msgb) |
| 91 | { |
| 92 | uint8_t *data = msgb_push(msgb, 2); |
| 93 | |
| 94 | data[0] = ASN1_NULL_TYPE_TAG; |
| 95 | data[1] = 0; |
| 96 | return data; |
| 97 | } |
| 98 | |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 99 | /* wrap an invoke around it... the other way around |
| 100 | * |
| 101 | * 1.) Invoke Component tag |
| 102 | * 2.) Invoke ID Tag |
| 103 | * 3.) Operation |
| 104 | * 4.) Data |
| 105 | */ |
| 106 | int gsm0480_wrap_invoke(struct msgb *msg, int op, int link_id) |
| 107 | { |
| 108 | /* 3. operation */ |
| 109 | msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, op); |
| 110 | |
| 111 | /* 2. invoke id tag */ |
| 112 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, link_id); |
| 113 | |
| 114 | /* 1. component tag */ |
| 115 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_INVOKE); |
| 116 | |
| 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | /* wrap the GSM 04.08 Facility IE around it */ |
| 121 | int gsm0480_wrap_facility(struct msgb *msg) |
| 122 | { |
| 123 | msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); |
| 124 | |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | struct msgb *gsm0480_create_unstructuredSS_Notify(int alertPattern, const char *text) |
| 129 | { |
| 130 | struct msgb *msg; |
| 131 | uint8_t *seq_len_ptr, *ussd_len_ptr, *data; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 132 | int len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 133 | |
| 134 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 135 | if (!msg) |
| 136 | return NULL; |
| 137 | |
| 138 | /* SEQUENCE { */ |
| 139 | msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG); |
| 140 | seq_len_ptr = msgb_put(msg, 1); |
| 141 | |
| 142 | /* DCS { */ |
| 143 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 144 | msgb_put_u8(msg, 1); |
| 145 | msgb_put_u8(msg, 0x0F); |
| 146 | /* } DCS */ |
| 147 | |
| 148 | /* USSD-String { */ |
| 149 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 150 | ussd_len_ptr = msgb_put(msg, 1); |
| 151 | data = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 152 | gsm_7bit_encode_n_ussd(data, msgb_tailroom(msg), text, &len); |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 153 | msgb_put(msg, len); |
| 154 | ussd_len_ptr[0] = len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 155 | /* USSD-String } */ |
| 156 | |
| 157 | /* alertingPattern { */ |
| 158 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 159 | msgb_put_u8(msg, 1); |
| 160 | msgb_put_u8(msg, alertPattern); |
| 161 | /* } alertingPattern */ |
| 162 | |
| 163 | seq_len_ptr[0] = 3 + 2 + ussd_len_ptr[0] + 3; |
| 164 | /* } SEQUENCE */ |
| 165 | |
| 166 | return msg; |
| 167 | } |
| 168 | |
| 169 | struct msgb *gsm0480_create_notifySS(const char *text) |
| 170 | { |
| 171 | struct msgb *msg; |
| 172 | uint8_t *data, *tmp_len; |
| 173 | uint8_t *seq_len_ptr, *cal_len_ptr, *opt_len_ptr, *nam_len_ptr; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 174 | int len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 175 | |
| 176 | len = strlen(text); |
| 177 | if (len < 1 || len > 160) |
| 178 | return NULL; |
| 179 | |
| 180 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 181 | if (!msg) |
| 182 | return NULL; |
| 183 | |
| 184 | msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG); |
| 185 | seq_len_ptr = msgb_put(msg, 1); |
| 186 | |
| 187 | /* ss_code for CNAP { */ |
| 188 | msgb_put_u8(msg, 0x81); |
| 189 | msgb_put_u8(msg, 1); |
| 190 | msgb_put_u8(msg, 0x19); |
| 191 | /* } ss_code */ |
| 192 | |
| 193 | |
| 194 | /* nameIndicator { */ |
| 195 | msgb_put_u8(msg, 0xB4); |
| 196 | nam_len_ptr = msgb_put(msg, 1); |
| 197 | |
| 198 | /* callingName { */ |
| 199 | msgb_put_u8(msg, 0xA0); |
| 200 | opt_len_ptr = msgb_put(msg, 1); |
| 201 | msgb_put_u8(msg, 0xA0); |
| 202 | cal_len_ptr = msgb_put(msg, 1); |
| 203 | |
| 204 | /* namePresentationAllowed { */ |
| 205 | /* add the DCS value */ |
| 206 | msgb_put_u8(msg, 0x80); |
| 207 | msgb_put_u8(msg, 1); |
| 208 | msgb_put_u8(msg, 0x0F); |
| 209 | |
| 210 | /* add the lengthInCharacters */ |
| 211 | msgb_put_u8(msg, 0x81); |
| 212 | msgb_put_u8(msg, 1); |
| 213 | msgb_put_u8(msg, strlen(text)); |
| 214 | |
| 215 | /* add the actual string */ |
| 216 | msgb_put_u8(msg, 0x82); |
| 217 | tmp_len = msgb_put(msg, 1); |
| 218 | data = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 219 | gsm_7bit_encode_n_ussd(data, msgb_tailroom(msg), text, &len); |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 220 | tmp_len[0] = len; |
| 221 | msgb_put(msg, len); |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 222 | |
| 223 | /* }; namePresentationAllowed */ |
| 224 | |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 225 | cal_len_ptr[0] = 3 + 3 + 2 + len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 226 | opt_len_ptr[0] = cal_len_ptr[0] + 2; |
| 227 | /* }; callingName */ |
| 228 | |
| 229 | nam_len_ptr[0] = opt_len_ptr[0] + 2; |
| 230 | /* ); nameIndicator */ |
| 231 | |
| 232 | /* write the lengths... */ |
| 233 | seq_len_ptr[0] = 3 + nam_len_ptr[0] + 2; |
| 234 | |
| 235 | return msg; |
| 236 | } |
| 237 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 238 | /* Forward declarations */ |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 239 | static int parse_ss(const struct gsm48_hdr *hdr, |
| 240 | uint16_t len, struct ss_request *req); |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 241 | static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len, |
| 242 | struct ss_request *req); |
Vadim Yanitskiy | b41c70f | 2018-01-17 12:10:07 +0600 | [diff] [blame] | 243 | static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 244 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 245 | static int parse_ss_invoke(const uint8_t *invoke_data, uint16_t length, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 246 | struct ss_request *req); |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 247 | static int parse_ss_return_result(const uint8_t *rr_data, uint16_t length, |
| 248 | struct ss_request *req); |
| 249 | static int parse_process_uss_data(const uint8_t *uss_req_data, uint16_t length, |
| 250 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 251 | static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 252 | struct ss_request *req); |
| 253 | static int parse_ss_for_bs_req(const uint8_t *ss_req_data, |
| 254 | uint16_t length, |
| 255 | struct ss_request *req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 256 | |
Vadim Yanitskiy | 52e4412 | 2018-06-11 03:51:11 +0700 | [diff] [blame] | 257 | /*! Get pointer to the IE of a given type |
| 258 | * \param[in] hdr Pointer to the message starting from header |
| 259 | * \param[in] msg_len Length of the whole message + header |
| 260 | * \param[out] ie External pointer to be set |
| 261 | * \param[out] ie_len External IE length variable |
| 262 | * \param[in] ie_tag Tag value of the required IE |
| 263 | * \returns 0 in case of success, otherwise -ERRNO |
| 264 | * |
| 265 | * This function iterates over existing IEs within a given |
| 266 | * message (depending on its type), and looks for the one with |
| 267 | * given \ref ie_tag value. If the IE is found, the external |
| 268 | * pointer pointed by \ref ie will be set to its value part |
| 269 | * (omitting TL), and \ref ie_len will be set to the length. |
| 270 | * Otherwise, e.g. in case of parsing error, both \ref ie |
| 271 | * and \ref ie_len are set to NULL and 0 respectively. |
| 272 | */ |
| 273 | int gsm0480_extract_ie_by_tag(const struct gsm48_hdr *hdr, uint16_t msg_len, |
| 274 | uint8_t **ie, uint16_t *ie_len, uint8_t ie_tag) |
| 275 | { |
| 276 | uint8_t pdisc, msg_type; |
| 277 | uint8_t *tlv, len; |
| 278 | |
| 279 | /* Init external variables */ |
| 280 | *ie_len = 0; |
| 281 | *ie = NULL; |
| 282 | |
| 283 | /* Drop incomplete / corrupted messages */ |
| 284 | if (msg_len < sizeof(*hdr)) |
| 285 | return -EINVAL; |
| 286 | |
| 287 | pdisc = gsm48_hdr_pdisc(hdr); |
| 288 | msg_type = gsm48_hdr_msg_type(hdr); |
| 289 | |
| 290 | /* Drop non-SS related messages */ |
| 291 | if (pdisc != GSM48_PDISC_NC_SS) |
| 292 | return -EINVAL; |
| 293 | |
| 294 | len = msg_len - sizeof(*hdr); |
| 295 | tlv = (uint8_t *) hdr->data; |
| 296 | |
| 297 | /* Parse a message depending on its type */ |
| 298 | switch (msg_type) { |
| 299 | /* See table 2.5: RELEASE COMPLETE message content */ |
| 300 | case GSM0480_MTYPE_RELEASE_COMPLETE: |
| 301 | /* See tables 2.3 and 2.4: REGISTER message content */ |
| 302 | case GSM0480_MTYPE_REGISTER: |
| 303 | /* Iterate over TLV-based IEs */ |
| 304 | while (len > 2) { |
| 305 | if (tlv[0] == ie_tag) { |
| 306 | *ie_len = tlv[1]; |
| 307 | *ie = tlv + 2; |
| 308 | return 0; |
| 309 | } |
| 310 | |
| 311 | len -= tlv[1] + 2; |
| 312 | tlv += tlv[1] + 2; |
| 313 | continue; |
| 314 | } |
| 315 | |
| 316 | /* The Facility IE is mandatory for REGISTER */ |
| 317 | if (msg_type == GSM0480_MTYPE_REGISTER) |
| 318 | if (ie_tag == GSM0480_IE_FACILITY) |
| 319 | return -EINVAL; |
| 320 | break; |
| 321 | |
| 322 | /* See table 2.2: FACILITY message content */ |
| 323 | case GSM0480_MTYPE_FACILITY: |
| 324 | /* There is no other IEs */ |
| 325 | if (ie_tag != GSM0480_IE_FACILITY) |
| 326 | break; |
| 327 | |
| 328 | /* Mandatory LV-based Facility IE */ |
| 329 | if (len < 2) |
| 330 | return -EINVAL; |
| 331 | |
| 332 | *ie_len = tlv[0]; |
| 333 | *ie = tlv + 1; |
| 334 | return 0; |
| 335 | |
| 336 | default: |
| 337 | /* Wrong message type, out of specs */ |
| 338 | return -EINVAL; |
| 339 | } |
| 340 | |
| 341 | return 0; |
| 342 | } |
| 343 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 344 | /* Decode a mobile-originated USSD-request message */ |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 345 | int gsm0480_decode_ussd_request(const struct gsm48_hdr *hdr, uint16_t len, |
| 346 | struct ussd_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 347 | { |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 348 | struct ss_request ss; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 349 | int rc = 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 350 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 351 | memset(&ss, 0, sizeof(ss)); |
| 352 | |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 353 | if (len < sizeof(*hdr) + 2) { |
| 354 | LOGP(0, LOGL_DEBUG, "USSD Request is too short.\n"); |
| 355 | return 0; |
| 356 | } |
| 357 | |
Neels Hofmeyr | 282e908 | 2016-03-14 16:06:46 +0100 | [diff] [blame] | 358 | if (gsm48_hdr_pdisc(hdr) == GSM48_PDISC_NC_SS) { |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 359 | req->transaction_id = hdr->proto_discr & 0x70; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 360 | |
| 361 | ss.transaction_id = req->transaction_id; |
Vadim Yanitskiy | 7689e0f | 2018-01-17 03:23:39 +0600 | [diff] [blame] | 362 | rc = parse_ss(hdr, len - sizeof(*hdr), &ss); |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 363 | |
| 364 | /* convert from ss_request to legacy ussd_request */ |
| 365 | req->transaction_id = ss.transaction_id; |
| 366 | req->invoke_id = ss.invoke_id; |
| 367 | if (ss.ussd_text[0] == 0xFF) |
| 368 | req->text[0] = '\0'; |
| 369 | else { |
| 370 | memcpy(req->text, ss.ussd_text, sizeof(req->text)); |
| 371 | req->text[sizeof(req->text)-1] = '\0'; |
| 372 | } |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 373 | } |
| 374 | |
| 375 | if (!rc) |
| 376 | LOGP(0, LOGL_DEBUG, "Error occurred while parsing received USSD!\n"); |
| 377 | |
| 378 | return rc; |
| 379 | } |
| 380 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 381 | /* Decode a mobile-originated SS request message */ |
| 382 | int gsm0480_decode_ss_request(const struct gsm48_hdr *hdr, uint16_t len, |
| 383 | struct ss_request *req) |
| 384 | { |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame] | 385 | uint8_t pdisc; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 386 | |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame] | 387 | /** |
| 388 | * Check Protocol Discriminator |
| 389 | * see TS GSM 04.07 and GSM 04.80 |
| 390 | */ |
| 391 | pdisc = gsm48_hdr_pdisc(hdr); |
| 392 | if (pdisc != GSM48_PDISC_NC_SS) { |
| 393 | LOGP(0, LOGL_ERROR, "Dropping message with " |
| 394 | "unsupported pdisc=%02x\n", pdisc); |
| 395 | return 0; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 396 | } |
| 397 | |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame] | 398 | /* GSM 04.80 3.3 Transaction Identifier */ |
| 399 | req->transaction_id = hdr->proto_discr & 0x70; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 400 | |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame] | 401 | /* Parse SS request */ |
| 402 | return parse_ss(hdr, len - sizeof(*hdr), req); |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 403 | } |
| 404 | |
| 405 | static int parse_ss(const struct gsm48_hdr *hdr, uint16_t len, struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 406 | { |
| 407 | int rc = 1; |
Neels Hofmeyr | a95ee5e | 2016-10-10 22:46:20 +0200 | [diff] [blame] | 408 | uint8_t msg_type = hdr->msg_type & 0x3F; /* message-type - section 3.4 */ |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 409 | |
Vadim Yanitskiy | fd744ce | 2018-01-17 03:31:15 +0600 | [diff] [blame] | 410 | /** |
| 411 | * GSM 04.80 Section 2.5 'Release complete' Table 2.5 |
| 412 | * payload is optional for 'RELEASE COMPLETE' message |
| 413 | */ |
| 414 | if (msg_type != GSM0480_MTYPE_RELEASE_COMPLETE) { |
| 415 | if (len < 2) { |
| 416 | LOGP(0, LOGL_DEBUG, "SS Request is too short.\n"); |
| 417 | return 0; |
| 418 | } |
| 419 | } |
| 420 | |
Vadim Yanitskiy | 44ebb93 | 2018-01-17 02:59:46 +0600 | [diff] [blame] | 421 | /* Table 2.1: Messages for call independent SS control */ |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 422 | switch (msg_type) { |
| 423 | case GSM0480_MTYPE_RELEASE_COMPLETE: |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 424 | LOGP(0, LOGL_DEBUG, "SS Release Complete\n"); |
Vadim Yanitskiy | 3cafc06 | 2018-01-17 12:28:40 +0600 | [diff] [blame] | 425 | |
Vadim Yanitskiy | fb5da89 | 2018-04-04 19:25:38 +0700 | [diff] [blame] | 426 | /** |
| 427 | * Indicates that there is no decoded message. |
| 428 | * To be overwriten by the message otherwise. |
| 429 | */ |
| 430 | req->ussd_text[0] = 0xFF; |
| 431 | |
Vadim Yanitskiy | 3cafc06 | 2018-01-17 12:28:40 +0600 | [diff] [blame] | 432 | /* Parse optional Cause and/or Facility data */ |
| 433 | if (len >= 2) |
| 434 | rc &= parse_ss_info_elements(&hdr->data[0], len, req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 435 | break; |
| 436 | case GSM0480_MTYPE_REGISTER: |
Vadim Yanitskiy | 7689e0f | 2018-01-17 03:23:39 +0600 | [diff] [blame] | 437 | rc &= parse_ss_info_elements(&hdr->data[0], len, req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 438 | break; |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 439 | case GSM0480_MTYPE_FACILITY: |
Vadim Yanitskiy | 7689e0f | 2018-01-17 03:23:39 +0600 | [diff] [blame] | 440 | rc &= parse_ss_facility(&hdr->data[0], len, req); |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 441 | break; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 442 | default: |
| 443 | LOGP(0, LOGL_DEBUG, "Unknown GSM 04.80 message-type field 0x%02x\n", |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 444 | hdr->msg_type); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 445 | rc = 0; |
| 446 | break; |
| 447 | } |
| 448 | |
| 449 | return rc; |
| 450 | } |
| 451 | |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 452 | static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len, |
| 453 | struct ss_request *req) |
| 454 | { |
| 455 | uint8_t facility_length; |
| 456 | |
| 457 | facility_length = ss_facility[0]; |
| 458 | if (len - 1 < facility_length) |
| 459 | return 0; |
| 460 | |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 461 | return !gsm0480_parse_facility_ie(ss_facility + 1, facility_length, req); |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 462 | } |
| 463 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 464 | static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, |
| 465 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 466 | { |
| 467 | int rc = -1; |
| 468 | /* Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 */ |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 469 | uint8_t iei; |
| 470 | uint8_t iei_length; |
| 471 | |
Vadim Yanitskiy | b92a27f | 2018-01-17 12:18:27 +0600 | [diff] [blame] | 472 | /* We need at least two bytes */ |
| 473 | if (len < 2) |
| 474 | return 0; |
| 475 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 476 | iei = ss_ie[0]; |
| 477 | iei_length = ss_ie[1]; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 478 | |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 479 | /* If the data does not fit, report an error */ |
Vadim Yanitskiy | b92a27f | 2018-01-17 12:18:27 +0600 | [diff] [blame] | 480 | if (iei_length + 2 > len) |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 481 | return 0; |
| 482 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 483 | switch (iei) { |
| 484 | case GSM48_IE_CAUSE: |
| 485 | break; |
| 486 | case GSM0480_IE_FACILITY: |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 487 | rc = !gsm0480_parse_facility_ie(ss_ie + 2, iei_length, req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 488 | break; |
| 489 | case GSM0480_IE_SS_VERSION: |
| 490 | break; |
| 491 | default: |
| 492 | LOGP(0, LOGL_DEBUG, "Unhandled GSM 04.08 or 04.80 IEI 0x%02x\n", |
| 493 | iei); |
| 494 | rc = 0; |
| 495 | break; |
| 496 | } |
| 497 | |
Vadim Yanitskiy | b92a27f | 2018-01-17 12:18:27 +0600 | [diff] [blame] | 498 | /* A message may contain multiple IEs */ |
| 499 | if (iei_length + 2 + 2 < len) |
| 500 | rc &= parse_ss_info_elements(ss_ie + iei_length + 2, |
| 501 | len - iei_length - 2, req); |
| 502 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 503 | return rc; |
| 504 | } |
| 505 | |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 506 | /*! Parse the components of a given Facility IE |
| 507 | * \param[in] facility_ie The Facility IE |
| 508 | * \param[in] length The length of Facility IE |
| 509 | * \param[out] req Abstract representation of SS message |
| 510 | * \return 0 in case of success, otherwise -ERRNO |
| 511 | */ |
| 512 | int gsm0480_parse_facility_ie(const uint8_t *facility_ie, uint16_t length, |
| 513 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 514 | { |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 515 | uint8_t component_length; |
| 516 | uint8_t component_type; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 517 | uint8_t offset = 0; |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 518 | int rc = 1; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 519 | |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 520 | /* Iterate over components within IE */ |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 521 | while (offset + 2 <= length) { |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 522 | /* Component Type tag - table 3.7 */ |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 523 | component_type = facility_ie[offset]; |
| 524 | component_length = facility_ie[offset + 1]; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 525 | |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 526 | /* Make sure that there is no overflow */ |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 527 | if (offset + 2 + component_length > length) { |
| 528 | LOGP(0, LOGL_ERROR, "Component does not fit.\n"); |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 529 | return -EINVAL; |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 530 | } |
| 531 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 532 | switch (component_type) { |
| 533 | case GSM0480_CTYPE_INVOKE: |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 534 | rc &= parse_ss_invoke(facility_ie + 2, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 535 | component_length, |
| 536 | req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 537 | break; |
| 538 | case GSM0480_CTYPE_RETURN_RESULT: |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 539 | rc &= parse_ss_return_result(facility_ie + 2, |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 540 | component_length, |
| 541 | req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 542 | break; |
| 543 | case GSM0480_CTYPE_RETURN_ERROR: |
| 544 | break; |
| 545 | case GSM0480_CTYPE_REJECT: |
| 546 | break; |
| 547 | default: |
| 548 | LOGP(0, LOGL_DEBUG, "Unknown GSM 04.80 Facility " |
| 549 | "Component Type 0x%02x\n", component_type); |
| 550 | rc = 0; |
| 551 | break; |
| 552 | } |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 553 | |
Vadim Yanitskiy | 5a09f75 | 2018-06-11 04:58:53 +0700 | [diff] [blame] | 554 | offset += (component_length + 2); |
| 555 | } |
| 556 | |
| 557 | /** |
| 558 | * The internal functions are using inverted return |
| 559 | * codes, where '0' means error/failure. While a |
| 560 | * common approach is to return negative errno in |
| 561 | * case of any failure, and '0' if all is ok. |
| 562 | */ |
| 563 | return (rc == 0) ? -EINVAL : 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 564 | } |
| 565 | |
| 566 | /* Parse an Invoke component - see table 3.3 */ |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 567 | static int parse_ss_invoke(const uint8_t *invoke_data, uint16_t length, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 568 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 569 | { |
| 570 | int rc = 1; |
| 571 | uint8_t offset; |
| 572 | |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 573 | if (length < 3) |
| 574 | return 0; |
| 575 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 576 | /* mandatory part */ |
| 577 | if (invoke_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) { |
| 578 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag " |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 579 | "0x%02x (expecting Invoke ID tag)\n", invoke_data[0]); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 580 | } |
| 581 | |
| 582 | offset = invoke_data[1] + 2; |
| 583 | req->invoke_id = invoke_data[2]; |
| 584 | |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 585 | /* look ahead once */ |
| 586 | if (offset + 1 > length) |
| 587 | return 0; |
| 588 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 589 | /* optional part */ |
| 590 | if (invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID) |
| 591 | offset += invoke_data[offset+1] + 2; /* skip over it */ |
| 592 | |
| 593 | /* mandatory part */ |
| 594 | if (invoke_data[offset] == GSM0480_OPERATION_CODE) { |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 595 | if (offset + 2 > length) |
| 596 | return 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 597 | uint8_t operation_code = invoke_data[offset+2]; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 598 | req->opcode = operation_code; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 599 | switch (operation_code) { |
Vadim Yanitskiy | 511426d | 2017-07-29 05:11:39 +0600 | [diff] [blame] | 600 | case GSM0480_OP_CODE_USS_NOTIFY: |
| 601 | case GSM0480_OP_CODE_USS_REQUEST: |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 602 | case GSM0480_OP_CODE_PROCESS_USS_REQ: |
| 603 | rc = parse_process_uss_req(invoke_data + offset + 3, |
| 604 | length - offset - 3, |
| 605 | req); |
| 606 | break; |
Vadim Yanitskiy | 394447b | 2017-07-29 05:14:15 +0600 | [diff] [blame] | 607 | case GSM0480_OP_CODE_PROCESS_USS_DATA: |
| 608 | rc = parse_process_uss_data(invoke_data + offset + 3, |
| 609 | length - offset - 3, |
| 610 | req); |
| 611 | break; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 612 | case GSM0480_OP_CODE_ACTIVATE_SS: |
| 613 | case GSM0480_OP_CODE_DEACTIVATE_SS: |
| 614 | case GSM0480_OP_CODE_INTERROGATE_SS: |
| 615 | rc = parse_ss_for_bs_req(invoke_data + offset + 3, |
| 616 | length - offset - 3, |
| 617 | req); |
| 618 | break; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 619 | default: |
| 620 | LOGP(0, LOGL_DEBUG, "GSM 04.80 operation code 0x%02x " |
| 621 | "is not yet handled\n", operation_code); |
| 622 | rc = 0; |
| 623 | break; |
| 624 | } |
| 625 | } else { |
| 626 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag 0x%02x " |
| 627 | "(expecting Operation Code tag)\n", |
| 628 | invoke_data[0]); |
| 629 | rc = 0; |
| 630 | } |
| 631 | |
| 632 | return rc; |
| 633 | } |
| 634 | |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 635 | /* Parse a Return Result component - see table 3.4 */ |
| 636 | static int parse_ss_return_result(const uint8_t *rr_data, uint16_t length, |
| 637 | struct ss_request *req) |
| 638 | { |
| 639 | uint8_t operation_code; |
| 640 | uint8_t offset; |
| 641 | |
| 642 | if (length < 3) |
| 643 | return 0; |
| 644 | |
| 645 | /* Mandatory part */ |
| 646 | if (rr_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) { |
| 647 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag " |
| 648 | "0x%02x (expecting Invoke ID tag)\n", rr_data[0]); |
| 649 | return 0; |
| 650 | } |
| 651 | |
| 652 | offset = rr_data[1] + 2; |
| 653 | req->invoke_id = rr_data[2]; |
| 654 | |
| 655 | if (offset >= length) |
| 656 | return 0; |
| 657 | |
| 658 | if (rr_data[offset] != GSM_0480_SEQUENCE_TAG) |
| 659 | return 0; |
| 660 | |
| 661 | if (offset + 2 > length) |
| 662 | return 0; |
| 663 | |
| 664 | offset += 2; |
| 665 | operation_code = rr_data[offset + 2]; |
| 666 | req->opcode = operation_code; |
| 667 | |
| 668 | switch (operation_code) { |
| 669 | case GSM0480_OP_CODE_USS_NOTIFY: |
| 670 | case GSM0480_OP_CODE_USS_REQUEST: |
| 671 | case GSM0480_OP_CODE_PROCESS_USS_REQ: |
| 672 | return parse_process_uss_req(rr_data + offset + 3, |
| 673 | length - offset - 3, req); |
| 674 | case GSM0480_OP_CODE_PROCESS_USS_DATA: |
| 675 | return parse_process_uss_data(rr_data + offset + 3, |
| 676 | length - offset - 3, req); |
| 677 | default: |
| 678 | LOGP(0, LOGL_DEBUG, "GSM 04.80 operation code 0x%02x " |
| 679 | "is not yet handled\n", operation_code); |
| 680 | return 0; |
| 681 | } |
| 682 | |
| 683 | return 1; |
| 684 | } |
| 685 | |
| 686 | static int parse_process_uss_data(const uint8_t *uss_req_data, uint16_t length, |
| 687 | struct ss_request *req) |
| 688 | { |
| 689 | uint8_t num_chars; |
| 690 | |
| 691 | /* we need at least that much */ |
| 692 | if (length < 3) |
| 693 | return 0; |
| 694 | |
| 695 | if (uss_req_data[0] != ASN1_IA5_STRING_TAG) |
| 696 | return 0; |
| 697 | |
| 698 | num_chars = uss_req_data[1]; |
| 699 | if (num_chars > length - 2) |
| 700 | return 0; |
| 701 | |
Vadim Yanitskiy | 2ecfb30 | 2018-04-04 19:19:07 +0700 | [diff] [blame] | 702 | /* Drop messages with incorrect length */ |
| 703 | if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) { |
| 704 | LOGP(DLGLOBAL, LOGL_ERROR, "Incorrect USS_DATA data length=%u, " |
| 705 | "dropping message", num_chars); |
| 706 | return 0; |
| 707 | } |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 708 | |
| 709 | memcpy(req->ussd_text, uss_req_data + 2, num_chars); |
| 710 | |
Vadim Yanitskiy | a24ead0 | 2018-04-04 10:34:41 +0700 | [diff] [blame] | 711 | /* Copy the data 'as is' */ |
| 712 | memcpy(req->ussd_data, uss_req_data + 2, num_chars); |
| 713 | req->ussd_data_len = num_chars; |
| 714 | req->ussd_data_dcs = 0x00; |
| 715 | |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 716 | return 1; |
| 717 | } |
| 718 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 719 | /* Parse the parameters of a Process UnstructuredSS Request */ |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 720 | static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 721 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 722 | { |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 723 | uint8_t num_chars; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 724 | uint8_t dcs; |
| 725 | |
Holger Hans Peter Freyther | d65a698 | 2010-10-11 09:23:50 +0200 | [diff] [blame] | 726 | /* we need at least that much */ |
| 727 | if (length < 8) |
| 728 | return 0; |
| 729 | |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 730 | if (uss_req_data[0] != GSM_0480_SEQUENCE_TAG) |
| 731 | return 0; |
Holger Hans Peter Freyther | d65a698 | 2010-10-11 09:23:50 +0200 | [diff] [blame] | 732 | |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 733 | /* Both 2th and 5th should be equal to ASN1_OCTET_STRING_TAG */ |
| 734 | if ((uss_req_data[2] & uss_req_data[5]) != ASN1_OCTET_STRING_TAG) |
| 735 | return 0; |
| 736 | |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 737 | /* Get DCS (Data Coding Scheme) */ |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 738 | dcs = uss_req_data[4]; |
Vadim Yanitskiy | a24ead0 | 2018-04-04 10:34:41 +0700 | [diff] [blame] | 739 | /* Get the amount of bytes */ |
| 740 | num_chars = uss_req_data[6]; |
| 741 | |
Vadim Yanitskiy | 2ecfb30 | 2018-04-04 19:19:07 +0700 | [diff] [blame] | 742 | /* Drop messages with incorrect length */ |
| 743 | if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) { |
| 744 | LOGP(DLGLOBAL, LOGL_ERROR, "Incorrect USS_REQ data length=%u, " |
| 745 | "dropping message", num_chars); |
| 746 | return 0; |
| 747 | } |
Vadim Yanitskiy | a24ead0 | 2018-04-04 10:34:41 +0700 | [diff] [blame] | 748 | |
| 749 | /* Copy the data 'as is' */ |
| 750 | memcpy(req->ussd_data, uss_req_data + 7, num_chars); |
| 751 | req->ussd_data_len = num_chars; |
| 752 | req->ussd_data_dcs = dcs; |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 753 | |
| 754 | /** |
| 755 | * According to GSM 04.08, 4.4.2 "ASN.1 data types": |
| 756 | * the USSD-DataCodingScheme shall indicate use of |
| 757 | * the default alphabet using the 0x0F value. |
| 758 | */ |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 759 | if (dcs == 0x0F) { |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 760 | /* Calculate the amount of 7-bit characters */ |
Vadim Yanitskiy | a24ead0 | 2018-04-04 10:34:41 +0700 | [diff] [blame] | 761 | num_chars = (num_chars * 8) / 7; |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 762 | |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 763 | gsm_7bit_decode_n_ussd((char *)req->ussd_text, |
| 764 | sizeof(req->ussd_text), &(uss_req_data[7]), num_chars); |
| 765 | |
| 766 | return 1; |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 767 | } else { |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 768 | memcpy(req->ussd_text, &(uss_req_data[7]), num_chars); |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 769 | return 1; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 770 | } |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 771 | |
| 772 | return 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 773 | } |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 774 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 775 | /* Parse the parameters of a Interrogate/Activate/DeactivateSS Request */ |
| 776 | static int parse_ss_for_bs_req(const uint8_t *ss_req_data, |
| 777 | uint16_t length, |
| 778 | struct ss_request *req) |
| 779 | { |
| 780 | int rc = 0; |
| 781 | |
| 782 | |
| 783 | /* we need at least that much */ |
| 784 | if (length < 5) |
| 785 | return 0; |
| 786 | |
| 787 | |
| 788 | if (ss_req_data[0] == GSM_0480_SEQUENCE_TAG) { |
| 789 | if ((ss_req_data[2] == ASN1_OCTET_STRING_TAG) && |
| 790 | ss_req_data[3] == 1) { |
| 791 | req->ss_code = ss_req_data[4]; |
| 792 | |
| 793 | rc = 1; |
| 794 | } |
| 795 | } |
| 796 | return rc; |
| 797 | } |
| 798 | |
Harald Welte | 88fa5a3 | 2018-07-28 22:55:43 +0200 | [diff] [blame] | 799 | struct msgb *gsm0480_msgb_alloc_name(const char *name) |
| 800 | { |
| 801 | return msgb_alloc_headroom(1024, 128, name); |
| 802 | } |
| 803 | |
Harald Welte | b0d9594 | 2018-07-28 23:02:48 +0200 | [diff] [blame] | 804 | /*! Generate a USSD ReturnResult component containing a string in default GSM alphabet. |
| 805 | * \param[in] invoke_id InvokeID of the request to which we respond |
| 806 | * \param[in] text USSD text in ASCII; to be encoded as GSM 7-but alphabet |
| 807 | */ |
| 808 | struct msgb *gsm0480_gen_ussd_resp_7bit(uint8_t invoke_id, const char *text) |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 809 | { |
| 810 | struct msgb *msg; |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 811 | uint8_t *ptr8; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 812 | int response_len; |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 813 | |
Harald Welte | 88fa5a3 | 2018-07-28 22:55:43 +0200 | [diff] [blame] | 814 | msg = gsm0480_msgb_alloc_name("TS 04.80 USSD Resp"); |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 815 | if (!msg) |
| 816 | return NULL; |
| 817 | |
| 818 | /* First put the payload text into the message */ |
| 819 | ptr8 = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 820 | gsm_7bit_encode_n_ussd(ptr8, msgb_tailroom(msg), text, &response_len); |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 821 | msgb_put(msg, response_len); |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 822 | |
| 823 | /* Then wrap it as an Octet String */ |
| 824 | msgb_wrap_with_TL(msg, ASN1_OCTET_STRING_TAG); |
| 825 | |
| 826 | /* Pre-pend the DCS octet string */ |
| 827 | msgb_push_TLV1(msg, ASN1_OCTET_STRING_TAG, 0x0F); |
| 828 | |
| 829 | /* Then wrap these as a Sequence */ |
| 830 | msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); |
| 831 | |
| 832 | /* Pre-pend the operation code */ |
| 833 | msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, |
| 834 | GSM0480_OP_CODE_PROCESS_USS_REQ); |
| 835 | |
| 836 | /* Wrap the operation code and IA5 string as a sequence */ |
| 837 | msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); |
| 838 | |
| 839 | /* Pre-pend the invoke ID */ |
| 840 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id); |
| 841 | |
| 842 | /* Wrap this up as a Return Result component */ |
| 843 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_RETURN_RESULT); |
| 844 | |
Harald Welte | b0d9594 | 2018-07-28 23:02:48 +0200 | [diff] [blame] | 845 | return msg; |
| 846 | } |
| 847 | |
| 848 | /*! Legacy helper: Generate USSD response including FACILITY IE + L3 header. |
| 849 | * |
| 850 | * This function is just like \ref gsm0480_gen_ussd_resp_7bit, but it generates |
| 851 | * not only the FACILITY value, but the full L3 message including message header |
| 852 | * and FACILITY IE Tag+Length. |
| 853 | */ |
| 854 | struct msgb *gsm0480_create_ussd_resp(uint8_t invoke_id, uint8_t trans_id, const char *text) |
| 855 | { |
| 856 | struct msgb *msg; |
| 857 | |
| 858 | msg = gsm0480_gen_ussd_resp_7bit(invoke_id, text); |
| 859 | if (!msg) |
| 860 | return NULL; |
| 861 | |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 862 | /* Wrap the component in a Facility message */ |
| 863 | msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); |
| 864 | |
| 865 | /* And finally pre-pend the L3 header */ |
Neels Hofmeyr | 25774b9 | 2016-11-26 15:21:05 +0100 | [diff] [blame] | 866 | gsm0480_l3hdr_push(msg, |
| 867 | GSM48_PDISC_NC_SS | trans_id |
| 868 | | (1<<7) /* TI direction = 1 */, |
| 869 | GSM0480_MTYPE_RELEASE_COMPLETE); |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 870 | return msg; |
| 871 | } |
Neels Hofmeyr | 25774b9 | 2016-11-26 15:21:05 +0100 | [diff] [blame] | 872 | |
Harald Welte | 7ecc4a3 | 2018-07-28 23:05:36 +0200 | [diff] [blame] | 873 | /*! Generate a ReturnError component (see section 3.6.1) and given error code (see section 3.6.6). |
| 874 | * \param[in] invoke_id InvokeID of the request |
| 875 | * \param[in] error_code Error code (section 4.5) |
| 876 | * \return message buffer containing the Reject component |
| 877 | * |
| 878 | * Note: if InvokeID is not available, e.g. when message parsing failed, any incorrect vlue |
| 879 | * can be passed (0x00 > x > 0xff), so the universal NULL-tag (see table 3.6) will be used instead. |
| 880 | */ |
| 881 | struct msgb *gsm0480_gen_return_error(uint8_t invoke_id, uint8_t error_code) |
| 882 | { |
| 883 | struct msgb *msg = gsm0480_msgb_alloc_name("TS 04.80 ReturnError"); |
| 884 | |
| 885 | /* First insert the problem code */ |
| 886 | msgb_push_TLV1(msg, GSM_0480_ERROR_CODE_TAG, error_code); |
| 887 | |
| 888 | /* Before it, insert the invoke ID */ |
| 889 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id); |
| 890 | |
| 891 | /* Wrap this up as a Reject component */ |
| 892 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_RETURN_ERROR); |
| 893 | |
| 894 | /* FIXME: Wrap in Facility + L3? */ |
| 895 | return msg; |
| 896 | } |
| 897 | |
| 898 | /*! Generate a Reject component (see section 3.6.1) and given error code (see section 3.6.7). |
| 899 | * \param[in] invoke_id InvokeID of the request |
| 900 | * \param[in] problem_tag Problem code tag (table 3.13) |
| 901 | * \param[in] problem_code Problem code (table 3.14-3.17) |
| 902 | * \return message buffer containing the Reject component |
| 903 | * |
| 904 | * Note: if InvokeID is not available, e.g. when message parsing failed, any incorrect vlue |
| 905 | * can be passed (0x00 > x > 0xff), so the universal NULL-tag (see table 3.6) will be used instead. |
| 906 | */ |
| 907 | struct msgb *gsm0480_gen_reject(int invoke_id, uint8_t problem_tag, uint8_t problem_code) |
| 908 | { |
| 909 | struct msgb *msg = gsm0480_msgb_alloc_name("TS 04.80 Reject"); |
| 910 | |
| 911 | /* First insert the problem code */ |
| 912 | msgb_push_TLV1(msg, problem_tag, problem_code); |
| 913 | |
| 914 | /* If the Invoke ID is not available, Universal NULL (table 3.9) with length=0 shall be used */ |
| 915 | if (invoke_id < 0 || invoke_id > 255) |
| 916 | msgb_push_NULL(msg); |
| 917 | else |
| 918 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id); |
| 919 | |
| 920 | /* Wrap this up as a Reject component */ |
| 921 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_REJECT); |
| 922 | |
| 923 | /* FIXME: Wrap in Facility + L3? */ |
| 924 | return msg; |
| 925 | } |
| 926 | |
| 927 | |
Neels Hofmeyr | 25774b9 | 2016-11-26 15:21:05 +0100 | [diff] [blame] | 928 | struct gsm48_hdr *gsm0480_l3hdr_push(struct msgb *msg, uint8_t proto_discr, |
| 929 | uint8_t msg_type) |
| 930 | { |
| 931 | struct gsm48_hdr *gh; |
| 932 | gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh)); |
| 933 | gh->proto_discr = proto_discr; |
| 934 | gh->msg_type = msg_type; |
| 935 | return gh; |
| 936 | } |
Neels Hofmeyr | bc1d758 | 2016-11-26 15:21:15 +0100 | [diff] [blame] | 937 | |
| 938 | struct msgb *gsm0480_create_ussd_notify(int level, const char *text) |
| 939 | { |
| 940 | struct msgb *msg; |
| 941 | |
| 942 | msg = gsm0480_create_unstructuredSS_Notify(level, text); |
| 943 | if (!msg) |
| 944 | return NULL; |
| 945 | |
| 946 | gsm0480_wrap_invoke(msg, GSM0480_OP_CODE_USS_NOTIFY, 0); |
| 947 | gsm0480_wrap_facility(msg); |
| 948 | |
| 949 | gsm0480_l3hdr_push(msg, GSM48_PDISC_NC_SS, GSM0480_MTYPE_REGISTER); |
| 950 | return msg; |
| 951 | } |
| 952 | |
| 953 | struct msgb *gsm0480_create_ussd_release_complete(void) |
| 954 | { |
| 955 | struct msgb *msg; |
| 956 | |
| 957 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80 USSD REL COMPL"); |
| 958 | if (!msg) |
| 959 | return NULL; |
| 960 | |
| 961 | /* FIXME: should this set trans_id and TI direction flag? */ |
| 962 | gsm0480_l3hdr_push(msg, GSM48_PDISC_NC_SS, |
| 963 | GSM0480_MTYPE_RELEASE_COMPLETE); |
| 964 | return msg; |
| 965 | } |