Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 1 | /* Format functions for GSM 04.80 */ |
| 2 | |
| 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 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License along |
| 20 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 21 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 22 | * |
| 23 | */ |
| 24 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 25 | #include <osmocom/gsm/gsm0480.h> |
| 26 | #include <osmocom/gsm/gsm_utils.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 27 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 28 | #include <osmocom/core/logging.h> |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 29 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 30 | #include <osmocom/gsm/protocol/gsm_04_08.h> |
| 31 | #include <osmocom/gsm/protocol/gsm_04_80.h> |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 32 | |
| 33 | #include <string.h> |
| 34 | |
| 35 | static inline unsigned char *msgb_wrap_with_TL(struct msgb *msgb, uint8_t tag) |
| 36 | { |
| 37 | uint8_t *data = msgb_push(msgb, 2); |
| 38 | |
| 39 | data[0] = tag; |
| 40 | data[1] = msgb->len - 2; |
| 41 | return data; |
| 42 | } |
| 43 | |
| 44 | static inline unsigned char *msgb_push_TLV1(struct msgb *msgb, uint8_t tag, |
| 45 | uint8_t value) |
| 46 | { |
| 47 | uint8_t *data = msgb_push(msgb, 3); |
| 48 | |
| 49 | data[0] = tag; |
| 50 | data[1] = 1; |
| 51 | data[2] = value; |
| 52 | return data; |
| 53 | } |
| 54 | |
| 55 | /* wrap an invoke around it... the other way around |
| 56 | * |
| 57 | * 1.) Invoke Component tag |
| 58 | * 2.) Invoke ID Tag |
| 59 | * 3.) Operation |
| 60 | * 4.) Data |
| 61 | */ |
| 62 | int gsm0480_wrap_invoke(struct msgb *msg, int op, int link_id) |
| 63 | { |
| 64 | /* 3. operation */ |
| 65 | msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, op); |
| 66 | |
| 67 | /* 2. invoke id tag */ |
| 68 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, link_id); |
| 69 | |
| 70 | /* 1. component tag */ |
| 71 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_INVOKE); |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | /* wrap the GSM 04.08 Facility IE around it */ |
| 77 | int gsm0480_wrap_facility(struct msgb *msg) |
| 78 | { |
| 79 | msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); |
| 80 | |
| 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | struct msgb *gsm0480_create_unstructuredSS_Notify(int alertPattern, const char *text) |
| 85 | { |
| 86 | struct msgb *msg; |
| 87 | uint8_t *seq_len_ptr, *ussd_len_ptr, *data; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 88 | int len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 89 | |
| 90 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 91 | if (!msg) |
| 92 | return NULL; |
| 93 | |
| 94 | /* SEQUENCE { */ |
| 95 | msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG); |
| 96 | seq_len_ptr = msgb_put(msg, 1); |
| 97 | |
| 98 | /* DCS { */ |
| 99 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 100 | msgb_put_u8(msg, 1); |
| 101 | msgb_put_u8(msg, 0x0F); |
| 102 | /* } DCS */ |
| 103 | |
| 104 | /* USSD-String { */ |
| 105 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 106 | ussd_len_ptr = msgb_put(msg, 1); |
| 107 | data = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 108 | 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] | 109 | msgb_put(msg, len); |
| 110 | ussd_len_ptr[0] = len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 111 | /* USSD-String } */ |
| 112 | |
| 113 | /* alertingPattern { */ |
| 114 | msgb_put_u8(msg, ASN1_OCTET_STRING_TAG); |
| 115 | msgb_put_u8(msg, 1); |
| 116 | msgb_put_u8(msg, alertPattern); |
| 117 | /* } alertingPattern */ |
| 118 | |
| 119 | seq_len_ptr[0] = 3 + 2 + ussd_len_ptr[0] + 3; |
| 120 | /* } SEQUENCE */ |
| 121 | |
| 122 | return msg; |
| 123 | } |
| 124 | |
| 125 | struct msgb *gsm0480_create_notifySS(const char *text) |
| 126 | { |
| 127 | struct msgb *msg; |
| 128 | uint8_t *data, *tmp_len; |
| 129 | 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] | 130 | int len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 131 | |
| 132 | len = strlen(text); |
| 133 | if (len < 1 || len > 160) |
| 134 | return NULL; |
| 135 | |
| 136 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 137 | if (!msg) |
| 138 | return NULL; |
| 139 | |
| 140 | msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG); |
| 141 | seq_len_ptr = msgb_put(msg, 1); |
| 142 | |
| 143 | /* ss_code for CNAP { */ |
| 144 | msgb_put_u8(msg, 0x81); |
| 145 | msgb_put_u8(msg, 1); |
| 146 | msgb_put_u8(msg, 0x19); |
| 147 | /* } ss_code */ |
| 148 | |
| 149 | |
| 150 | /* nameIndicator { */ |
| 151 | msgb_put_u8(msg, 0xB4); |
| 152 | nam_len_ptr = msgb_put(msg, 1); |
| 153 | |
| 154 | /* callingName { */ |
| 155 | msgb_put_u8(msg, 0xA0); |
| 156 | opt_len_ptr = msgb_put(msg, 1); |
| 157 | msgb_put_u8(msg, 0xA0); |
| 158 | cal_len_ptr = msgb_put(msg, 1); |
| 159 | |
| 160 | /* namePresentationAllowed { */ |
| 161 | /* add the DCS value */ |
| 162 | msgb_put_u8(msg, 0x80); |
| 163 | msgb_put_u8(msg, 1); |
| 164 | msgb_put_u8(msg, 0x0F); |
| 165 | |
| 166 | /* add the lengthInCharacters */ |
| 167 | msgb_put_u8(msg, 0x81); |
| 168 | msgb_put_u8(msg, 1); |
| 169 | msgb_put_u8(msg, strlen(text)); |
| 170 | |
| 171 | /* add the actual string */ |
| 172 | msgb_put_u8(msg, 0x82); |
| 173 | tmp_len = msgb_put(msg, 1); |
| 174 | data = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 175 | 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] | 176 | tmp_len[0] = len; |
| 177 | msgb_put(msg, len); |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 178 | |
| 179 | /* }; namePresentationAllowed */ |
| 180 | |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 181 | cal_len_ptr[0] = 3 + 3 + 2 + len; |
Holger Hans Peter Freyther | 55aea50 | 2010-09-30 18:30:41 +0800 | [diff] [blame] | 182 | opt_len_ptr[0] = cal_len_ptr[0] + 2; |
| 183 | /* }; callingName */ |
| 184 | |
| 185 | nam_len_ptr[0] = opt_len_ptr[0] + 2; |
| 186 | /* ); nameIndicator */ |
| 187 | |
| 188 | /* write the lengths... */ |
| 189 | seq_len_ptr[0] = 3 + nam_len_ptr[0] + 2; |
| 190 | |
| 191 | return msg; |
| 192 | } |
| 193 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 194 | /* Forward declarations */ |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 195 | static int parse_ss(const struct gsm48_hdr *hdr, |
| 196 | uint16_t len, struct ss_request *req); |
| 197 | static int parse_ss_info_elements(const uint8_t *ussd_ie, uint16_t len, |
| 198 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 199 | 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] | 200 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 201 | 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] | 202 | struct ss_request *req); |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 203 | 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] | 204 | struct ss_request *req); |
| 205 | static int parse_ss_for_bs_req(const uint8_t *ss_req_data, |
| 206 | uint16_t length, |
| 207 | struct ss_request *req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 208 | |
| 209 | /* Decode a mobile-originated USSD-request message */ |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 210 | int gsm0480_decode_ussd_request(const struct gsm48_hdr *hdr, uint16_t len, |
| 211 | struct ussd_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 212 | { |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 213 | struct ss_request ss; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 214 | int rc = 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 215 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 216 | memset(&ss, 0, sizeof(ss)); |
| 217 | |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 218 | if (len < sizeof(*hdr) + 2) { |
| 219 | LOGP(0, LOGL_DEBUG, "USSD Request is too short.\n"); |
| 220 | return 0; |
| 221 | } |
| 222 | |
Neels Hofmeyr | 282e908 | 2016-03-14 16:06:46 +0100 | [diff] [blame] | 223 | if (gsm48_hdr_pdisc(hdr) == GSM48_PDISC_NC_SS) { |
Holger Hans Peter Freyther | daa653f | 2010-10-11 07:56:06 +0200 | [diff] [blame] | 224 | req->transaction_id = hdr->proto_discr & 0x70; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 225 | |
| 226 | ss.transaction_id = req->transaction_id; |
| 227 | rc = parse_ss(hdr, len, &ss); |
| 228 | |
| 229 | /* convert from ss_request to legacy ussd_request */ |
| 230 | req->transaction_id = ss.transaction_id; |
| 231 | req->invoke_id = ss.invoke_id; |
| 232 | if (ss.ussd_text[0] == 0xFF) |
| 233 | req->text[0] = '\0'; |
| 234 | else { |
| 235 | memcpy(req->text, ss.ussd_text, sizeof(req->text)); |
| 236 | req->text[sizeof(req->text)-1] = '\0'; |
| 237 | } |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 238 | } |
| 239 | |
| 240 | if (!rc) |
| 241 | LOGP(0, LOGL_DEBUG, "Error occurred while parsing received USSD!\n"); |
| 242 | |
| 243 | return rc; |
| 244 | } |
| 245 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 246 | /* Decode a mobile-originated SS request message */ |
| 247 | int gsm0480_decode_ss_request(const struct gsm48_hdr *hdr, uint16_t len, |
| 248 | struct ss_request *req) |
| 249 | { |
| 250 | int rc = 0; |
| 251 | |
| 252 | if (len < sizeof(*hdr) + 2) { |
| 253 | LOGP(0, LOGL_DEBUG, "SS Request is too short.\n"); |
| 254 | return 0; |
| 255 | } |
| 256 | |
Neels Hofmeyr | 282e908 | 2016-03-14 16:06:46 +0100 | [diff] [blame] | 257 | if (gsm48_hdr_pdisc(hdr) == GSM48_PDISC_NC_SS) { |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 258 | req->transaction_id = hdr->proto_discr & 0x70; |
| 259 | rc = parse_ss(hdr, len, req); |
| 260 | } |
| 261 | |
| 262 | if (!rc) |
| 263 | LOGP(0, LOGL_DEBUG, "Error occurred while parsing received SS!\n"); |
| 264 | |
| 265 | return rc; |
| 266 | } |
| 267 | |
| 268 | 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] | 269 | { |
| 270 | int rc = 1; |
Neels Hofmeyr | a95ee5e | 2016-10-10 22:46:20 +0200 | [diff] [blame] | 271 | 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] | 272 | |
| 273 | switch (msg_type) { |
| 274 | case GSM0480_MTYPE_RELEASE_COMPLETE: |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 275 | LOGP(0, LOGL_DEBUG, "SS Release Complete\n"); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 276 | /* could also parse out the optional Cause/Facility data */ |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 277 | req->ussd_text[0] = 0xFF; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 278 | break; |
| 279 | case GSM0480_MTYPE_REGISTER: |
| 280 | case GSM0480_MTYPE_FACILITY: |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 281 | rc &= parse_ss_info_elements(&hdr->data[0], len - sizeof(*hdr), req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 282 | break; |
| 283 | default: |
| 284 | 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] | 285 | hdr->msg_type); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 286 | rc = 0; |
| 287 | break; |
| 288 | } |
| 289 | |
| 290 | return rc; |
| 291 | } |
| 292 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 293 | static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, |
| 294 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 295 | { |
| 296 | int rc = -1; |
| 297 | /* 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] | 298 | uint8_t iei; |
| 299 | uint8_t iei_length; |
| 300 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 301 | iei = ss_ie[0]; |
| 302 | iei_length = ss_ie[1]; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 303 | |
Holger Hans Peter Freyther | 8ac0486 | 2010-10-11 08:08:58 +0200 | [diff] [blame] | 304 | /* If the data does not fit, report an error */ |
| 305 | if (len - 2 < iei_length) |
| 306 | return 0; |
| 307 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 308 | switch (iei) { |
| 309 | case GSM48_IE_CAUSE: |
| 310 | break; |
| 311 | case GSM0480_IE_FACILITY: |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 312 | rc = parse_facility_ie(ss_ie + 2, iei_length, req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 313 | break; |
| 314 | case GSM0480_IE_SS_VERSION: |
| 315 | break; |
| 316 | default: |
| 317 | LOGP(0, LOGL_DEBUG, "Unhandled GSM 04.08 or 04.80 IEI 0x%02x\n", |
| 318 | iei); |
| 319 | rc = 0; |
| 320 | break; |
| 321 | } |
| 322 | |
| 323 | return rc; |
| 324 | } |
| 325 | |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 326 | 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] | 327 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 328 | { |
| 329 | int rc = 1; |
| 330 | uint8_t offset = 0; |
| 331 | |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 332 | while (offset + 2 <= length) { |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 333 | /* Component Type tag - table 3.7 */ |
| 334 | uint8_t component_type = facility_ie[offset]; |
| 335 | uint8_t component_length = facility_ie[offset+1]; |
| 336 | |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 337 | /* size check */ |
| 338 | if (offset + 2 + component_length > length) { |
| 339 | LOGP(0, LOGL_ERROR, "Component does not fit.\n"); |
| 340 | return 0; |
| 341 | } |
| 342 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 343 | switch (component_type) { |
| 344 | case GSM0480_CTYPE_INVOKE: |
| 345 | rc &= parse_ss_invoke(facility_ie+2, |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 346 | component_length, |
| 347 | req); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 348 | break; |
| 349 | case GSM0480_CTYPE_RETURN_RESULT: |
| 350 | break; |
| 351 | case GSM0480_CTYPE_RETURN_ERROR: |
| 352 | break; |
| 353 | case GSM0480_CTYPE_REJECT: |
| 354 | break; |
| 355 | default: |
| 356 | LOGP(0, LOGL_DEBUG, "Unknown GSM 04.80 Facility " |
| 357 | "Component Type 0x%02x\n", component_type); |
| 358 | rc = 0; |
| 359 | break; |
| 360 | } |
| 361 | offset += (component_length+2); |
Holger Hans Peter Freyther | 4156ec6 | 2010-10-11 09:07:50 +0200 | [diff] [blame] | 362 | }; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 363 | |
| 364 | return rc; |
| 365 | } |
| 366 | |
| 367 | /* Parse an Invoke component - see table 3.3 */ |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 368 | 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] | 369 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 370 | { |
| 371 | int rc = 1; |
| 372 | uint8_t offset; |
| 373 | |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 374 | if (length < 3) |
| 375 | return 0; |
| 376 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 377 | /* mandatory part */ |
| 378 | if (invoke_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) { |
| 379 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag " |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 380 | "0x%02x (expecting Invoke ID tag)\n", invoke_data[0]); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 381 | } |
| 382 | |
| 383 | offset = invoke_data[1] + 2; |
| 384 | req->invoke_id = invoke_data[2]; |
| 385 | |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 386 | /* look ahead once */ |
| 387 | if (offset + 1 > length) |
| 388 | return 0; |
| 389 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 390 | /* optional part */ |
| 391 | if (invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID) |
| 392 | offset += invoke_data[offset+1] + 2; /* skip over it */ |
| 393 | |
| 394 | /* mandatory part */ |
| 395 | if (invoke_data[offset] == GSM0480_OPERATION_CODE) { |
Holger Hans Peter Freyther | 7d0bce3 | 2010-10-11 09:12:33 +0200 | [diff] [blame] | 396 | if (offset + 2 > length) |
| 397 | return 0; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 398 | uint8_t operation_code = invoke_data[offset+2]; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 399 | req->opcode = operation_code; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 400 | switch (operation_code) { |
| 401 | case GSM0480_OP_CODE_PROCESS_USS_REQ: |
| 402 | rc = parse_process_uss_req(invoke_data + offset + 3, |
| 403 | length - offset - 3, |
| 404 | req); |
| 405 | break; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 406 | case GSM0480_OP_CODE_ACTIVATE_SS: |
| 407 | case GSM0480_OP_CODE_DEACTIVATE_SS: |
| 408 | case GSM0480_OP_CODE_INTERROGATE_SS: |
| 409 | rc = parse_ss_for_bs_req(invoke_data + offset + 3, |
| 410 | length - offset - 3, |
| 411 | req); |
| 412 | break; |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 413 | default: |
| 414 | LOGP(0, LOGL_DEBUG, "GSM 04.80 operation code 0x%02x " |
| 415 | "is not yet handled\n", operation_code); |
| 416 | rc = 0; |
| 417 | break; |
| 418 | } |
| 419 | } else { |
| 420 | LOGP(0, LOGL_DEBUG, "Unexpected GSM 04.80 Component-ID tag 0x%02x " |
| 421 | "(expecting Operation Code tag)\n", |
| 422 | invoke_data[0]); |
| 423 | rc = 0; |
| 424 | } |
| 425 | |
| 426 | return rc; |
| 427 | } |
| 428 | |
| 429 | /* Parse the parameters of a Process UnstructuredSS Request */ |
Holger Hans Peter Freyther | 49ad500 | 2010-10-11 09:06:47 +0200 | [diff] [blame] | 430 | 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] | 431 | struct ss_request *req) |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 432 | { |
| 433 | int rc = 0; |
| 434 | int num_chars; |
| 435 | uint8_t dcs; |
| 436 | |
Holger Hans Peter Freyther | d65a698 | 2010-10-11 09:23:50 +0200 | [diff] [blame] | 437 | |
| 438 | /* we need at least that much */ |
| 439 | if (length < 8) |
| 440 | return 0; |
| 441 | |
| 442 | |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 443 | if (uss_req_data[0] == GSM_0480_SEQUENCE_TAG) { |
| 444 | if (uss_req_data[2] == ASN1_OCTET_STRING_TAG) { |
| 445 | dcs = uss_req_data[4]; |
| 446 | if ((dcs == 0x0F) && |
| 447 | (uss_req_data[5] == ASN1_OCTET_STRING_TAG)) { |
| 448 | num_chars = (uss_req_data[6] * 8) / 7; |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 449 | /* Prevent a mobile-originated buffer-overrun! */ |
| 450 | if (num_chars > MAX_LEN_USSD_STRING) |
| 451 | num_chars = MAX_LEN_USSD_STRING; |
| 452 | gsm_7bit_decode_n_ussd((char *)req->ussd_text, |
| 453 | sizeof(req->ussd_text), |
| 454 | &(uss_req_data[7]), num_chars); |
Holger Hans Peter Freyther | 00cb570 | 2010-10-09 01:47:15 +0800 | [diff] [blame] | 455 | rc = 1; |
| 456 | } |
| 457 | } |
| 458 | } |
| 459 | return rc; |
| 460 | } |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 461 | |
Tobias Engel | 419684e | 2012-03-08 13:31:52 +0100 | [diff] [blame] | 462 | /* Parse the parameters of a Interrogate/Activate/DeactivateSS Request */ |
| 463 | static int parse_ss_for_bs_req(const uint8_t *ss_req_data, |
| 464 | uint16_t length, |
| 465 | struct ss_request *req) |
| 466 | { |
| 467 | int rc = 0; |
| 468 | |
| 469 | |
| 470 | /* we need at least that much */ |
| 471 | if (length < 5) |
| 472 | return 0; |
| 473 | |
| 474 | |
| 475 | if (ss_req_data[0] == GSM_0480_SEQUENCE_TAG) { |
| 476 | if ((ss_req_data[2] == ASN1_OCTET_STRING_TAG) && |
| 477 | ss_req_data[3] == 1) { |
| 478 | req->ss_code = ss_req_data[4]; |
| 479 | |
| 480 | rc = 1; |
| 481 | } |
| 482 | } |
| 483 | return rc; |
| 484 | } |
| 485 | |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 486 | struct msgb *gsm0480_create_ussd_resp(uint8_t invoke_id, uint8_t trans_id, const char *text) |
| 487 | { |
| 488 | struct msgb *msg; |
| 489 | struct gsm48_hdr *gh; |
| 490 | uint8_t *ptr8; |
Holger Hans Peter Freyther | 47aa482 | 2013-07-07 13:54:53 +0200 | [diff] [blame] | 491 | int response_len; |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 492 | |
| 493 | msg = msgb_alloc_headroom(1024, 128, "GSM 04.80"); |
| 494 | if (!msg) |
| 495 | return NULL; |
| 496 | |
| 497 | /* First put the payload text into the message */ |
| 498 | ptr8 = msgb_put(msg, 0); |
Jacob Erlbeck | 1d7f3b5 | 2013-08-12 17:07:53 +0200 | [diff] [blame] | 499 | 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] | 500 | msgb_put(msg, response_len); |
Holger Hans Peter Freyther | c64970e | 2010-10-18 16:56:43 +0200 | [diff] [blame] | 501 | |
| 502 | /* Then wrap it as an Octet String */ |
| 503 | msgb_wrap_with_TL(msg, ASN1_OCTET_STRING_TAG); |
| 504 | |
| 505 | /* Pre-pend the DCS octet string */ |
| 506 | msgb_push_TLV1(msg, ASN1_OCTET_STRING_TAG, 0x0F); |
| 507 | |
| 508 | /* Then wrap these as a Sequence */ |
| 509 | msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); |
| 510 | |
| 511 | /* Pre-pend the operation code */ |
| 512 | msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, |
| 513 | GSM0480_OP_CODE_PROCESS_USS_REQ); |
| 514 | |
| 515 | /* Wrap the operation code and IA5 string as a sequence */ |
| 516 | msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); |
| 517 | |
| 518 | /* Pre-pend the invoke ID */ |
| 519 | msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id); |
| 520 | |
| 521 | /* Wrap this up as a Return Result component */ |
| 522 | msgb_wrap_with_TL(msg, GSM0480_CTYPE_RETURN_RESULT); |
| 523 | |
| 524 | /* Wrap the component in a Facility message */ |
| 525 | msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); |
| 526 | |
| 527 | /* And finally pre-pend the L3 header */ |
| 528 | gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh)); |
| 529 | gh->proto_discr = GSM48_PDISC_NC_SS | trans_id |
| 530 | | (1<<7); /* TI direction = 1 */ |
| 531 | gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE; |
| 532 | |
| 533 | return msg; |
| 534 | } |