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