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> |
| 6 | * |
| 7 | * All Rights Reserved |
| 8 | * |
Harald Welte | e08da97 | 2017-11-13 01:00:26 +0900 | [diff] [blame] | 9 | * SPDX-License-Identifier: GPL-2.0+ |
| 10 | * |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 11 | * This program is free software; you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License as published by |
| 13 | * the Free Software Foundation; either version 2 of the License, or |
| 14 | * (at your option) any later version. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License along |
| 22 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 23 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 24 | * |
| 25 | */ |
| 26 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 27 | #include <osmocom/gsm/gsm0480.h> |
| 28 | #include <osmocom/gsm/gsm_utils.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 29 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 30 | #include <osmocom/core/logging.h> |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 31 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 32 | #include <osmocom/gsm/protocol/gsm_04_08.h> |
| 33 | #include <osmocom/gsm/protocol/gsm_04_80.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 34 | |
| 35 | #include <string.h> |
| 36 | |
| 37 | static inline unsigned char *msgb_wrap_with_TL(struct msgb *msgb, uint8_t tag) |
| 38 | { |
| 39 | uint8_t *data = msgb_push(msgb, 2); |
| 40 | |
| 41 | data[0] = tag; |
| 42 | data[1] = msgb->len - 2; |
| 43 | return data; |
| 44 | } |
| 45 | |
| 46 | static inline unsigned char *msgb_push_TLV1(struct msgb *msgb, uint8_t tag, |
| 47 | uint8_t value) |
| 48 | { |
| 49 | uint8_t *data = msgb_push(msgb, 3); |
| 50 | |
| 51 | data[0] = tag; |
| 52 | data[1] = 1; |
| 53 | data[2] = value; |
| 54 | return data; |
| 55 | } |
| 56 | |
| 57 | /* wrap an invoke around it... the other way around |
| 58 | * |
| 59 | * 1.) Invoke Component tag |
| 60 | * 2.) Invoke ID Tag |
| 61 | * 3.) Operation |
| 62 | * 4.) Data |
| 63 | */ |
| 64 | int gsm0480_wrap_invoke(struct msgb *msg, int op, int link_id) |
| 65 | { |
| 66 | /* 3. operation */ |
| 67 | msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, op); |
| 68 | |
| 69 | /* 2. invoke id tag */ |
| 70 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, link_id); |
| 71 | |
| 72 | /* 1. component tag */ |
| 73 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_INVOKE); |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | /* wrap the GSM 04.08 Facility IE around it */ |
| 79 | int gsm0480_wrap_facility(struct msgb *msg) |
| 80 | { |
| 81 | msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); |
| 82 | |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | struct msgb *gsm0480_create_unstructuredSS_Notify(int alertPattern, const char *text) |
| 87 | { |
| 88 | struct msgb *msg; |
| 89 | uint8_t *seq_len_ptr, *ussd_len_ptr, *data; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 90 | int len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 91 | |
| 92 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 93 | if (!msg) |
| 94 | return NULL; |
| 95 | |
| 96 | /* SEQUENCE { */ |
| 97 | msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG); |
| 98 | seq_len_ptr = msgb_put(msg, 1); |
| 99 | |
| 100 | /* DCS { */ |
| 101 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 102 | msgb_put_u8(msg, 1); |
| 103 | msgb_put_u8(msg, 0x0F); |
| 104 | /* } DCS */ |
| 105 | |
| 106 | /* USSD-String { */ |
| 107 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 108 | ussd_len_ptr = msgb_put(msg, 1); |
| 109 | data = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 110 | 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] | 111 | msgb_put(msg, len); |
| 112 | ussd_len_ptr[0] = len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 113 | /* USSD-String } */ |
| 114 | |
| 115 | /* alertingPattern { */ |
| 116 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 117 | msgb_put_u8(msg, 1); |
| 118 | msgb_put_u8(msg, alertPattern); |
| 119 | /* } alertingPattern */ |
| 120 | |
| 121 | seq_len_ptr[0] = 3 + 2 + ussd_len_ptr[0] + 3; |
| 122 | /* } SEQUENCE */ |
| 123 | |
| 124 | return msg; |
| 125 | } |
| 126 | |
| 127 | struct msgb *gsm0480_create_notifySS(const char *text) |
| 128 | { |
| 129 | struct msgb *msg; |
| 130 | uint8_t *data, *tmp_len; |
| 131 | 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] | 132 | int len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 133 | |
| 134 | len = strlen(text); |
| 135 | if (len < 1 || len > 160) |
| 136 | return NULL; |
| 137 | |
| 138 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 139 | if (!msg) |
| 140 | return NULL; |
| 141 | |
| 142 | msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG); |
| 143 | seq_len_ptr = msgb_put(msg, 1); |
| 144 | |
| 145 | /* ss_code for CNAP { */ |
| 146 | msgb_put_u8(msg, 0x81); |
| 147 | msgb_put_u8(msg, 1); |
| 148 | msgb_put_u8(msg, 0x19); |
| 149 | /* } ss_code */ |
| 150 | |
| 151 | |
| 152 | /* nameIndicator { */ |
| 153 | msgb_put_u8(msg, 0xB4); |
| 154 | nam_len_ptr = msgb_put(msg, 1); |
| 155 | |
| 156 | /* callingName { */ |
| 157 | msgb_put_u8(msg, 0xA0); |
| 158 | opt_len_ptr = msgb_put(msg, 1); |
| 159 | msgb_put_u8(msg, 0xA0); |
| 160 | cal_len_ptr = msgb_put(msg, 1); |
| 161 | |
| 162 | /* namePresentationAllowed { */ |
| 163 | /* add the DCS value */ |
| 164 | msgb_put_u8(msg, 0x80); |
| 165 | msgb_put_u8(msg, 1); |
| 166 | msgb_put_u8(msg, 0x0F); |
| 167 | |
| 168 | /* add the lengthInCharacters */ |
| 169 | msgb_put_u8(msg, 0x81); |
| 170 | msgb_put_u8(msg, 1); |
| 171 | msgb_put_u8(msg, strlen(text)); |
| 172 | |
| 173 | /* add the actual string */ |
| 174 | msgb_put_u8(msg, 0x82); |
| 175 | tmp_len = msgb_put(msg, 1); |
| 176 | data = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 177 | 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] | 178 | tmp_len[0] = len; |
| 179 | msgb_put(msg, len); |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 180 | |
| 181 | /* }; namePresentationAllowed */ |
| 182 | |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 183 | cal_len_ptr[0] = 3 + 3 + 2 + len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 184 | opt_len_ptr[0] = cal_len_ptr[0] + 2; |
| 185 | /* }; callingName */ |
| 186 | |
| 187 | nam_len_ptr[0] = opt_len_ptr[0] + 2; |
| 188 | /* ); nameIndicator */ |
| 189 | |
| 190 | /* write the lengths... */ |
| 191 | seq_len_ptr[0] = 3 + nam_len_ptr[0] + 2; |
| 192 | |
| 193 | return msg; |
| 194 | } |
| 195 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 196 | /* Forward declarations */ |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 197 | static int parse_ss(const struct gsm48_hdr *hdr, |
| 198 | uint16_t len, struct ss_request *req); |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 199 | static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len, |
| 200 | struct ss_request *req); |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 201 | static int parse_ss_info_elements(const uint8_t *ussd_ie, uint16_t len, |
| 202 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 203 | static int parse_facility_ie(const uint8_t *facility_ie, uint16_t length, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 204 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 205 | 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] | 206 | struct ss_request *req); |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 207 | static int parse_ss_return_result(const uint8_t *rr_data, uint16_t length, |
| 208 | struct ss_request *req); |
| 209 | static int parse_process_uss_data(const uint8_t *uss_req_data, uint16_t length, |
| 210 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 211 | 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] | 212 | struct ss_request *req); |
| 213 | static int parse_ss_for_bs_req(const uint8_t *ss_req_data, |
| 214 | uint16_t length, |
| 215 | struct ss_request *req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 216 | |
| 217 | /* Decode a mobile-originated USSD-request message */ |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 218 | int gsm0480_decode_ussd_request(const struct gsm48_hdr *hdr, uint16_t len, |
| 219 | struct ussd_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 220 | { |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 221 | struct ss_request ss; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 222 | int rc = 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 223 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 224 | memset(&ss, 0, sizeof(ss)); |
| 225 | |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 226 | if (len < sizeof(*hdr) + 2) { |
| 227 | LOGP(0, LOGL_DEBUG, "USSD Request is too short.\n"); |
| 228 | return 0; |
| 229 | } |
| 230 | |
Neels Hofmeyr | 282e908 | 2016-03-14 16:06:46 +0100 | [diff] [blame] | 231 | if (gsm48_hdr_pdisc(hdr) == GSM48_PDISC_NC_SS) { |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 232 | req->transaction_id = hdr->proto_discr & 0x70; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 233 | |
| 234 | ss.transaction_id = req->transaction_id; |
Vadim Yanitskiy | 7689e0f | 2018-01-17 03:23:39 +0600 | [diff] [blame] | 235 | rc = parse_ss(hdr, len - sizeof(*hdr), &ss); |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 236 | |
| 237 | /* convert from ss_request to legacy ussd_request */ |
| 238 | req->transaction_id = ss.transaction_id; |
| 239 | req->invoke_id = ss.invoke_id; |
| 240 | if (ss.ussd_text[0] == 0xFF) |
| 241 | req->text[0] = '\0'; |
| 242 | else { |
| 243 | memcpy(req->text, ss.ussd_text, sizeof(req->text)); |
| 244 | req->text[sizeof(req->text)-1] = '\0'; |
| 245 | } |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 246 | } |
| 247 | |
| 248 | if (!rc) |
| 249 | LOGP(0, LOGL_DEBUG, "Error occurred while parsing received USSD!\n"); |
| 250 | |
| 251 | return rc; |
| 252 | } |
| 253 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 254 | /* Decode a mobile-originated SS request message */ |
| 255 | int gsm0480_decode_ss_request(const struct gsm48_hdr *hdr, uint16_t len, |
| 256 | struct ss_request *req) |
| 257 | { |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame^] | 258 | uint8_t pdisc; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 259 | |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame^] | 260 | /** |
| 261 | * Check Protocol Discriminator |
| 262 | * see TS GSM 04.07 and GSM 04.80 |
| 263 | */ |
| 264 | pdisc = gsm48_hdr_pdisc(hdr); |
| 265 | if (pdisc != GSM48_PDISC_NC_SS) { |
| 266 | LOGP(0, LOGL_ERROR, "Dropping message with " |
| 267 | "unsupported pdisc=%02x\n", pdisc); |
| 268 | return 0; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 269 | } |
| 270 | |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame^] | 271 | /* GSM 04.80 3.3 Transaction Identifier */ |
| 272 | req->transaction_id = hdr->proto_discr & 0x70; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 273 | |
Vadim Yanitskiy | f07c58c | 2018-01-17 03:42:16 +0600 | [diff] [blame^] | 274 | /* Parse SS request */ |
| 275 | return parse_ss(hdr, len - sizeof(*hdr), req); |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 276 | } |
| 277 | |
| 278 | 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] | 279 | { |
| 280 | int rc = 1; |
Neels Hofmeyr | a95ee5e | 2016-10-10 22:46:20 +0200 | [diff] [blame] | 281 | 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] | 282 | |
Vadim Yanitskiy | fd744ce | 2018-01-17 03:31:15 +0600 | [diff] [blame] | 283 | /** |
| 284 | * GSM 04.80 Section 2.5 'Release complete' Table 2.5 |
| 285 | * payload is optional for 'RELEASE COMPLETE' message |
| 286 | */ |
| 287 | if (msg_type != GSM0480_MTYPE_RELEASE_COMPLETE) { |
| 288 | if (len < 2) { |
| 289 | LOGP(0, LOGL_DEBUG, "SS Request is too short.\n"); |
| 290 | return 0; |
| 291 | } |
| 292 | } |
| 293 | |
Vadim Yanitskiy | 44ebb93 | 2018-01-17 02:59:46 +0600 | [diff] [blame] | 294 | /* Table 2.1: Messages for call independent SS control */ |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 295 | switch (msg_type) { |
| 296 | case GSM0480_MTYPE_RELEASE_COMPLETE: |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 297 | LOGP(0, LOGL_DEBUG, "SS Release Complete\n"); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 298 | /* could also parse out the optional Cause/Facility data */ |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 299 | req->ussd_text[0] = 0xFF; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 300 | break; |
| 301 | case GSM0480_MTYPE_REGISTER: |
Vadim Yanitskiy | 7689e0f | 2018-01-17 03:23:39 +0600 | [diff] [blame] | 302 | rc &= parse_ss_info_elements(&hdr->data[0], len, req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 303 | break; |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 304 | case GSM0480_MTYPE_FACILITY: |
Vadim Yanitskiy | 7689e0f | 2018-01-17 03:23:39 +0600 | [diff] [blame] | 305 | rc &= parse_ss_facility(&hdr->data[0], len, req); |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 306 | break; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 307 | default: |
| 308 | 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] | 309 | hdr->msg_type); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 310 | rc = 0; |
| 311 | break; |
| 312 | } |
| 313 | |
| 314 | return rc; |
| 315 | } |
| 316 | |
Vadim Yanitskiy | c30431f | 2017-07-29 04:47:42 +0600 | [diff] [blame] | 317 | static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len, |
| 318 | struct ss_request *req) |
| 319 | { |
| 320 | uint8_t facility_length; |
| 321 | |
| 322 | facility_length = ss_facility[0]; |
| 323 | if (len - 1 < facility_length) |
| 324 | return 0; |
| 325 | |
| 326 | return parse_facility_ie(ss_facility + 1, facility_length, req); |
| 327 | } |
| 328 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 329 | static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, |
| 330 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 331 | { |
| 332 | int rc = -1; |
| 333 | /* 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] | 334 | uint8_t iei; |
| 335 | uint8_t iei_length; |
| 336 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 337 | iei = ss_ie[0]; |
| 338 | iei_length = ss_ie[1]; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 339 | |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 340 | /* If the data does not fit, report an error */ |
| 341 | if (len - 2 < iei_length) |
| 342 | return 0; |
| 343 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 344 | switch (iei) { |
| 345 | case GSM48_IE_CAUSE: |
| 346 | break; |
| 347 | case GSM0480_IE_FACILITY: |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 348 | rc = parse_facility_ie(ss_ie + 2, iei_length, req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 349 | break; |
| 350 | case GSM0480_IE_SS_VERSION: |
| 351 | break; |
| 352 | default: |
| 353 | LOGP(0, LOGL_DEBUG, "Unhandled GSM 04.08 or 04.80 IEI 0x%02x\n", |
| 354 | iei); |
| 355 | rc = 0; |
| 356 | break; |
| 357 | } |
| 358 | |
| 359 | return rc; |
| 360 | } |
| 361 | |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 362 | static int parse_facility_ie(const uint8_t *facility_ie, uint16_t length, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 363 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 364 | { |
| 365 | int rc = 1; |
| 366 | uint8_t offset = 0; |
| 367 | |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 368 | while (offset + 2 <= length) { |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 369 | /* Component Type tag - table 3.7 */ |
| 370 | uint8_t component_type = facility_ie[offset]; |
| 371 | uint8_t component_length = facility_ie[offset+1]; |
| 372 | |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 373 | /* size check */ |
| 374 | if (offset + 2 + component_length > length) { |
| 375 | LOGP(0, LOGL_ERROR, "Component does not fit.\n"); |
| 376 | return 0; |
| 377 | } |
| 378 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 379 | switch (component_type) { |
| 380 | case GSM0480_CTYPE_INVOKE: |
| 381 | rc &= parse_ss_invoke(facility_ie+2, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 382 | component_length, |
| 383 | req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 384 | break; |
| 385 | case GSM0480_CTYPE_RETURN_RESULT: |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 386 | rc &= parse_ss_return_result(facility_ie+2, |
| 387 | component_length, |
| 388 | req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 389 | break; |
| 390 | case GSM0480_CTYPE_RETURN_ERROR: |
| 391 | break; |
| 392 | case GSM0480_CTYPE_REJECT: |
| 393 | break; |
| 394 | default: |
| 395 | LOGP(0, LOGL_DEBUG, "Unknown GSM 04.80 Facility " |
| 396 | "Component Type 0x%02x\n", component_type); |
| 397 | rc = 0; |
| 398 | break; |
| 399 | } |
| 400 | offset += (component_length+2); |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 401 | }; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 402 | |
| 403 | return rc; |
| 404 | } |
| 405 | |
| 406 | /* Parse an Invoke component - see table 3.3 */ |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 407 | 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] | 408 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 409 | { |
| 410 | int rc = 1; |
| 411 | uint8_t offset; |
| 412 | |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 413 | if (length < 3) |
| 414 | return 0; |
| 415 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 416 | /* mandatory part */ |
| 417 | if (invoke_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) { |
| 418 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag " |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 419 | "0x%02x (expecting Invoke ID tag)\n", invoke_data[0]); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 420 | } |
| 421 | |
| 422 | offset = invoke_data[1] + 2; |
| 423 | req->invoke_id = invoke_data[2]; |
| 424 | |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 425 | /* look ahead once */ |
| 426 | if (offset + 1 > length) |
| 427 | return 0; |
| 428 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 429 | /* optional part */ |
| 430 | if (invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID) |
| 431 | offset += invoke_data[offset+1] + 2; /* skip over it */ |
| 432 | |
| 433 | /* mandatory part */ |
| 434 | if (invoke_data[offset] == GSM0480_OPERATION_CODE) { |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 435 | if (offset + 2 > length) |
| 436 | return 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 437 | uint8_t operation_code = invoke_data[offset+2]; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 438 | req->opcode = operation_code; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 439 | switch (operation_code) { |
Vadim Yanitskiy | 511426d | 2017-07-29 05:11:39 +0600 | [diff] [blame] | 440 | case GSM0480_OP_CODE_USS_NOTIFY: |
| 441 | case GSM0480_OP_CODE_USS_REQUEST: |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 442 | case GSM0480_OP_CODE_PROCESS_USS_REQ: |
| 443 | rc = parse_process_uss_req(invoke_data + offset + 3, |
| 444 | length - offset - 3, |
| 445 | req); |
| 446 | break; |
Vadim Yanitskiy | 394447b | 2017-07-29 05:14:15 +0600 | [diff] [blame] | 447 | case GSM0480_OP_CODE_PROCESS_USS_DATA: |
| 448 | rc = parse_process_uss_data(invoke_data + offset + 3, |
| 449 | length - offset - 3, |
| 450 | req); |
| 451 | break; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 452 | case GSM0480_OP_CODE_ACTIVATE_SS: |
| 453 | case GSM0480_OP_CODE_DEACTIVATE_SS: |
| 454 | case GSM0480_OP_CODE_INTERROGATE_SS: |
| 455 | rc = parse_ss_for_bs_req(invoke_data + offset + 3, |
| 456 | length - offset - 3, |
| 457 | req); |
| 458 | break; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 459 | default: |
| 460 | LOGP(0, LOGL_DEBUG, "GSM 04.80 operation code 0x%02x " |
| 461 | "is not yet handled\n", operation_code); |
| 462 | rc = 0; |
| 463 | break; |
| 464 | } |
| 465 | } else { |
| 466 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag 0x%02x " |
| 467 | "(expecting Operation Code tag)\n", |
| 468 | invoke_data[0]); |
| 469 | rc = 0; |
| 470 | } |
| 471 | |
| 472 | return rc; |
| 473 | } |
| 474 | |
Vadim Yanitskiy | 7f16c44 | 2017-07-29 05:05:54 +0600 | [diff] [blame] | 475 | /* Parse a Return Result component - see table 3.4 */ |
| 476 | static int parse_ss_return_result(const uint8_t *rr_data, uint16_t length, |
| 477 | struct ss_request *req) |
| 478 | { |
| 479 | uint8_t operation_code; |
| 480 | uint8_t offset; |
| 481 | |
| 482 | if (length < 3) |
| 483 | return 0; |
| 484 | |
| 485 | /* Mandatory part */ |
| 486 | if (rr_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) { |
| 487 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag " |
| 488 | "0x%02x (expecting Invoke ID tag)\n", rr_data[0]); |
| 489 | return 0; |
| 490 | } |
| 491 | |
| 492 | offset = rr_data[1] + 2; |
| 493 | req->invoke_id = rr_data[2]; |
| 494 | |
| 495 | if (offset >= length) |
| 496 | return 0; |
| 497 | |
| 498 | if (rr_data[offset] != GSM_0480_SEQUENCE_TAG) |
| 499 | return 0; |
| 500 | |
| 501 | if (offset + 2 > length) |
| 502 | return 0; |
| 503 | |
| 504 | offset += 2; |
| 505 | operation_code = rr_data[offset + 2]; |
| 506 | req->opcode = operation_code; |
| 507 | |
| 508 | switch (operation_code) { |
| 509 | case GSM0480_OP_CODE_USS_NOTIFY: |
| 510 | case GSM0480_OP_CODE_USS_REQUEST: |
| 511 | case GSM0480_OP_CODE_PROCESS_USS_REQ: |
| 512 | return parse_process_uss_req(rr_data + offset + 3, |
| 513 | length - offset - 3, req); |
| 514 | case GSM0480_OP_CODE_PROCESS_USS_DATA: |
| 515 | return parse_process_uss_data(rr_data + offset + 3, |
| 516 | length - offset - 3, req); |
| 517 | default: |
| 518 | LOGP(0, LOGL_DEBUG, "GSM 04.80 operation code 0x%02x " |
| 519 | "is not yet handled\n", operation_code); |
| 520 | return 0; |
| 521 | } |
| 522 | |
| 523 | return 1; |
| 524 | } |
| 525 | |
| 526 | static int parse_process_uss_data(const uint8_t *uss_req_data, uint16_t length, |
| 527 | struct ss_request *req) |
| 528 | { |
| 529 | uint8_t num_chars; |
| 530 | |
| 531 | /* we need at least that much */ |
| 532 | if (length < 3) |
| 533 | return 0; |
| 534 | |
| 535 | if (uss_req_data[0] != ASN1_IA5_STRING_TAG) |
| 536 | return 0; |
| 537 | |
| 538 | num_chars = uss_req_data[1]; |
| 539 | if (num_chars > length - 2) |
| 540 | return 0; |
| 541 | |
| 542 | if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) |
| 543 | num_chars = GSM0480_USSD_OCTET_STRING_LEN; |
| 544 | |
| 545 | memcpy(req->ussd_text, uss_req_data + 2, num_chars); |
| 546 | |
| 547 | return 1; |
| 548 | } |
| 549 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 550 | /* Parse the parameters of a Process UnstructuredSS Request */ |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 551 | 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] | 552 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 553 | { |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 554 | uint8_t num_chars; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 555 | uint8_t dcs; |
| 556 | |
Holger Hans Peter Freyther | d65a698 | 2010-10-11 09:23:50 +0200 | [diff] [blame] | 557 | /* we need at least that much */ |
| 558 | if (length < 8) |
| 559 | return 0; |
| 560 | |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 561 | if (uss_req_data[0] != GSM_0480_SEQUENCE_TAG) |
| 562 | return 0; |
Holger Hans Peter Freyther | d65a698 | 2010-10-11 09:23:50 +0200 | [diff] [blame] | 563 | |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 564 | /* Both 2th and 5th should be equal to ASN1_OCTET_STRING_TAG */ |
| 565 | if ((uss_req_data[2] & uss_req_data[5]) != ASN1_OCTET_STRING_TAG) |
| 566 | return 0; |
| 567 | |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 568 | /* Get DCS (Data Coding Scheme) */ |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 569 | dcs = uss_req_data[4]; |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 570 | |
| 571 | /** |
| 572 | * According to GSM 04.08, 4.4.2 "ASN.1 data types": |
| 573 | * the USSD-DataCodingScheme shall indicate use of |
| 574 | * the default alphabet using the 0x0F value. |
| 575 | */ |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 576 | if (dcs == 0x0F) { |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 577 | /* Calculate the amount of 7-bit characters */ |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 578 | num_chars = (uss_req_data[6] * 8) / 7; |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 579 | |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 580 | /* Prevent a mobile-originated buffer-overrun! */ |
| 581 | if (num_chars > GSM0480_USSD_7BIT_STRING_LEN) |
| 582 | num_chars = GSM0480_USSD_7BIT_STRING_LEN; |
| 583 | |
| 584 | gsm_7bit_decode_n_ussd((char *)req->ussd_text, |
| 585 | sizeof(req->ussd_text), &(uss_req_data[7]), num_chars); |
| 586 | |
| 587 | return 1; |
Vadim Yanitskiy | 01b8572 | 2017-07-29 04:43:48 +0600 | [diff] [blame] | 588 | } else { |
| 589 | /* Get the amount of 8-bit characters */ |
| 590 | num_chars = uss_req_data[6]; |
| 591 | |
| 592 | /* Prevent a mobile-originated buffer-overrun! */ |
| 593 | if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) |
| 594 | num_chars = GSM0480_USSD_OCTET_STRING_LEN; |
| 595 | |
| 596 | memcpy(req->ussd_text, &(uss_req_data[7]), num_chars); |
| 597 | |
| 598 | return 1; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 599 | } |
Vadim Yanitskiy | 5b0790d | 2017-07-29 04:26:21 +0600 | [diff] [blame] | 600 | |
| 601 | return 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 602 | } |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 603 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 604 | /* Parse the parameters of a Interrogate/Activate/DeactivateSS Request */ |
| 605 | static int parse_ss_for_bs_req(const uint8_t *ss_req_data, |
| 606 | uint16_t length, |
| 607 | struct ss_request *req) |
| 608 | { |
| 609 | int rc = 0; |
| 610 | |
| 611 | |
| 612 | /* we need at least that much */ |
| 613 | if (length < 5) |
| 614 | return 0; |
| 615 | |
| 616 | |
| 617 | if (ss_req_data[0] == GSM_0480_SEQUENCE_TAG) { |
| 618 | if ((ss_req_data[2] == ASN1_OCTET_STRING_TAG) && |
| 619 | ss_req_data[3] == 1) { |
| 620 | req->ss_code = ss_req_data[4]; |
| 621 | |
| 622 | rc = 1; |
| 623 | } |
| 624 | } |
| 625 | return rc; |
| 626 | } |
| 627 | |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 628 | struct msgb *gsm0480_create_ussd_resp(uint8_t invoke_id, uint8_t trans_id, const char *text) |
| 629 | { |
| 630 | struct msgb *msg; |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 631 | uint8_t *ptr8; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 632 | int response_len; |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 633 | |
| 634 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 635 | if (!msg) |
| 636 | return NULL; |
| 637 | |
| 638 | /* First put the payload text into the message */ |
| 639 | ptr8 = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 640 | 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] | 641 | msgb_put(msg, response_len); |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 642 | |
| 643 | /* Then wrap it as an Octet String */ |
| 644 | msgb_wrap_with_TL(msg, ASN1_OCTET_STRING_TAG); |
| 645 | |
| 646 | /* Pre-pend the DCS octet string */ |
| 647 | msgb_push_TLV1(msg, ASN1_OCTET_STRING_TAG, 0x0F); |
| 648 | |
| 649 | /* Then wrap these as a Sequence */ |
| 650 | msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); |
| 651 | |
| 652 | /* Pre-pend the operation code */ |
| 653 | msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, |
| 654 | GSM0480_OP_CODE_PROCESS_USS_REQ); |
| 655 | |
| 656 | /* Wrap the operation code and IA5 string as a sequence */ |
| 657 | msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); |
| 658 | |
| 659 | /* Pre-pend the invoke ID */ |
| 660 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id); |
| 661 | |
| 662 | /* Wrap this up as a Return Result component */ |
| 663 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_RETURN_RESULT); |
| 664 | |
| 665 | /* Wrap the component in a Facility message */ |
| 666 | msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); |
| 667 | |
| 668 | /* And finally pre-pend the L3 header */ |
Neels Hofmeyr | 25774b9 | 2016-11-26 15:21:05 +0100 | [diff] [blame] | 669 | gsm0480_l3hdr_push(msg, |
| 670 | GSM48_PDISC_NC_SS | trans_id |
| 671 | | (1<<7) /* TI direction = 1 */, |
| 672 | GSM0480_MTYPE_RELEASE_COMPLETE); |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 673 | return msg; |
| 674 | } |
Neels Hofmeyr | 25774b9 | 2016-11-26 15:21:05 +0100 | [diff] [blame] | 675 | |
| 676 | struct gsm48_hdr *gsm0480_l3hdr_push(struct msgb *msg, uint8_t proto_discr, |
| 677 | uint8_t msg_type) |
| 678 | { |
| 679 | struct gsm48_hdr *gh; |
| 680 | gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh)); |
| 681 | gh->proto_discr = proto_discr; |
| 682 | gh->msg_type = msg_type; |
| 683 | return gh; |
| 684 | } |
Neels Hofmeyr | bc1d758 | 2016-11-26 15:21:15 +0100 | [diff] [blame] | 685 | |
| 686 | struct msgb *gsm0480_create_ussd_notify(int level, const char *text) |
| 687 | { |
| 688 | struct msgb *msg; |
| 689 | |
| 690 | msg = gsm0480_create_unstructuredSS_Notify(level, text); |
| 691 | if (!msg) |
| 692 | return NULL; |
| 693 | |
| 694 | gsm0480_wrap_invoke(msg, GSM0480_OP_CODE_USS_NOTIFY, 0); |
| 695 | gsm0480_wrap_facility(msg); |
| 696 | |
| 697 | gsm0480_l3hdr_push(msg, GSM48_PDISC_NC_SS, GSM0480_MTYPE_REGISTER); |
| 698 | return msg; |
| 699 | } |
| 700 | |
| 701 | struct msgb *gsm0480_create_ussd_release_complete(void) |
| 702 | { |
| 703 | struct msgb *msg; |
| 704 | |
| 705 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80 USSD REL COMPL"); |
| 706 | if (!msg) |
| 707 | return NULL; |
| 708 | |
| 709 | /* FIXME: should this set trans_id and TI direction flag? */ |
| 710 | gsm0480_l3hdr_push(msg, GSM48_PDISC_NC_SS, |
| 711 | GSM0480_MTYPE_RELEASE_COMPLETE); |
| 712 | return msg; |
| 713 | } |