Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 1 | /* GPRS LLC protocol implementation as per 3GPP TS 04.64 */ |
| 2 | |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 3 | /* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org> |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 4 | * |
| 5 | * All Rights Reserved |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
Harald Welte | 0e3e88e | 2011-01-01 15:25:50 +0100 | [diff] [blame] | 8 | * it under the terms of the GNU Affero General Public License as published by |
| 9 | * the Free Software Foundation; either version 3 of the License, or |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
Harald Welte | 0e3e88e | 2011-01-01 15:25:50 +0100 | [diff] [blame] | 15 | * GNU Affero General Public License for more details. |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 16 | * |
Harald Welte | 0e3e88e | 2011-01-01 15:25:50 +0100 | [diff] [blame] | 17 | * You should have received a copy of the GNU Affero General Public License |
| 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <errno.h> |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 23 | #include <stdint.h> |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 24 | |
Pablo Neira Ayuso | dd5fff4 | 2011-03-22 16:47:59 +0100 | [diff] [blame] | 25 | #include <osmocom/core/msgb.h> |
| 26 | #include <osmocom/core/linuxlist.h> |
| 27 | #include <osmocom/core/timer.h> |
| 28 | #include <osmocom/core/talloc.h> |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 29 | |
| 30 | #include <openbsc/gsm_data.h> |
| 31 | #include <openbsc/debug.h> |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 32 | #include <openbsc/gprs_sgsn.h> |
| 33 | #include <openbsc/gprs_gmm.h> |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 34 | #include <openbsc/gprs_bssgp.h> |
| 35 | #include <openbsc/gprs_llc.h> |
| 36 | #include <openbsc/crc24.h> |
Holger Hans Peter Freyther | f9839f6 | 2011-10-14 23:42:13 +0200 | [diff] [blame] | 37 | #include <openbsc/sgsn.h> |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 38 | |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 39 | /* Section 8.9.9 LLC layer parameter default values */ |
| 40 | static const struct gprs_llc_params llc_default_params[] = { |
| 41 | [1] = { |
| 42 | .t200_201 = 5, |
| 43 | .n200 = 3, |
| 44 | .n201_u = 400, |
| 45 | }, |
| 46 | [2] = { |
| 47 | .t200_201 = 5, |
| 48 | .n200 = 3, |
| 49 | .n201_u = 270, |
| 50 | }, |
| 51 | [3] = { |
| 52 | .iov_i_exp = 27, |
| 53 | .t200_201 = 5, |
| 54 | .n200 = 3, |
| 55 | .n201_u = 500, |
| 56 | .n201_i = 1503, |
| 57 | .mD = 1520, |
| 58 | .mU = 1520, |
| 59 | .kD = 16, |
| 60 | .kU = 16, |
| 61 | }, |
| 62 | [5] = { |
| 63 | .iov_i_exp = 27, |
| 64 | .t200_201 = 10, |
| 65 | .n200 = 3, |
| 66 | .n201_u = 500, |
| 67 | .n201_i = 1503, |
| 68 | .mD = 760, |
| 69 | .mU = 760, |
| 70 | .kD = 8, |
| 71 | .kU = 8, |
| 72 | }, |
| 73 | [7] = { |
| 74 | .t200_201 = 20, |
| 75 | .n200 = 3, |
| 76 | .n201_u = 270, |
| 77 | }, |
| 78 | [8] = { |
| 79 | .t200_201 = 20, |
| 80 | .n200 = 3, |
| 81 | .n201_u = 270, |
| 82 | }, |
| 83 | [9] = { |
| 84 | .iov_i_exp = 27, |
| 85 | .t200_201 = 20, |
| 86 | .n200 = 3, |
| 87 | .n201_u = 500, |
| 88 | .n201_i = 1503, |
| 89 | .mD = 380, |
| 90 | .mU = 380, |
| 91 | .kD = 4, |
| 92 | .kU = 4, |
| 93 | }, |
| 94 | [11] = { |
| 95 | .iov_i_exp = 27, |
| 96 | .t200_201 = 40, |
| 97 | .n200 = 3, |
| 98 | .n201_u = 500, |
| 99 | .n201_i = 1503, |
| 100 | .mD = 190, |
| 101 | .mU = 190, |
| 102 | .kD = 2, |
| 103 | .kU = 2, |
| 104 | }, |
| 105 | }; |
| 106 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 107 | LLIST_HEAD(gprs_llc_llmes); |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 108 | void *llc_tall_ctx; |
| 109 | |
Harald Welte | 66d062a | 2010-12-26 10:39:26 +0100 | [diff] [blame] | 110 | /* If the TLLI is foreign, return its local version */ |
| 111 | static inline uint32_t tlli_foreign2local(uint32_t tlli) |
| 112 | { |
| 113 | uint32_t new_tlli; |
| 114 | |
| 115 | if (gprs_tlli_type(tlli) == TLLI_FOREIGN) { |
| 116 | new_tlli = tlli | 0x40000000; |
| 117 | DEBUGP(DLLC, "TLLI 0x%08x is foreign, converting to " |
| 118 | "local TLLI 0x%08x\n", tlli, new_tlli); |
| 119 | } else |
| 120 | new_tlli = tlli; |
| 121 | |
| 122 | return new_tlli; |
| 123 | } |
| 124 | |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 125 | /* lookup LLC Entity based on DLCI (TLLI+SAPI tuple) */ |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 126 | static struct gprs_llc_lle *lle_by_tlli_sapi(uint32_t tlli, uint8_t sapi) |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 127 | { |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 128 | struct gprs_llc_llme *llme; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 129 | |
Harald Welte | 66d062a | 2010-12-26 10:39:26 +0100 | [diff] [blame] | 130 | tlli = tlli_foreign2local(tlli); |
| 131 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 132 | llist_for_each_entry(llme, &gprs_llc_llmes, list) { |
| 133 | if (llme->tlli == tlli || llme->old_tlli == tlli) |
| 134 | return &llme->lle[sapi]; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 135 | } |
| 136 | return NULL; |
| 137 | } |
| 138 | |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 139 | static void lle_init(struct gprs_llc_llme *llme, uint8_t sapi) |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 140 | { |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 141 | struct gprs_llc_lle *lle = &llme->lle[sapi]; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 142 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 143 | lle->llme = llme; |
| 144 | lle->sapi = sapi; |
| 145 | lle->state = GPRS_LLES_UNASSIGNED; |
| 146 | |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 147 | /* Initialize according to parameters */ |
| 148 | memcpy(&lle->params, &llc_default_params[sapi], sizeof(lle->params)); |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 149 | } |
| 150 | |
| 151 | static struct gprs_llc_llme *llme_alloc(uint32_t tlli) |
| 152 | { |
| 153 | struct gprs_llc_llme *llme; |
| 154 | uint32_t i; |
| 155 | |
| 156 | llme = talloc_zero(llc_tall_ctx, struct gprs_llc_llme); |
| 157 | if (!llme) |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 158 | return NULL; |
| 159 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 160 | llme->tlli = tlli; |
Harald Welte | b3d84a4 | 2010-07-01 11:54:31 +0200 | [diff] [blame] | 161 | llme->old_tlli = 0xffffffff; |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 162 | llme->state = GPRS_LLMS_UNASSIGNED; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 163 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 164 | for (i = 0; i < ARRAY_SIZE(llme->lle); i++) |
| 165 | lle_init(llme, i); |
| 166 | |
| 167 | llist_add(&llme->list, &gprs_llc_llmes); |
| 168 | |
| 169 | return llme; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 170 | } |
| 171 | |
Harald Welte | 7a62a3a | 2010-06-28 22:18:26 +0200 | [diff] [blame] | 172 | static void llme_free(struct gprs_llc_llme *llme) |
| 173 | { |
| 174 | llist_del(&llme->list); |
| 175 | talloc_free(llme); |
| 176 | } |
| 177 | |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 178 | enum gprs_llc_cmd { |
| 179 | GPRS_LLC_NULL, |
| 180 | GPRS_LLC_RR, |
| 181 | GPRS_LLC_ACK, |
| 182 | GPRS_LLC_RNR, |
| 183 | GPRS_LLC_SACK, |
| 184 | GPRS_LLC_DM, |
| 185 | GPRS_LLC_DISC, |
| 186 | GPRS_LLC_UA, |
| 187 | GPRS_LLC_SABM, |
| 188 | GPRS_LLC_FRMR, |
| 189 | GPRS_LLC_XID, |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 190 | GPRS_LLC_UI, |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 191 | }; |
| 192 | |
Harald Welte | 366c204 | 2010-05-18 12:31:50 +0200 | [diff] [blame] | 193 | static const struct value_string llc_cmd_strs[] = { |
| 194 | { GPRS_LLC_NULL, "NULL" }, |
| 195 | { GPRS_LLC_RR, "RR" }, |
| 196 | { GPRS_LLC_ACK, "ACK" }, |
| 197 | { GPRS_LLC_RNR, "RNR" }, |
| 198 | { GPRS_LLC_SACK, "SACK" }, |
| 199 | { GPRS_LLC_DM, "DM" }, |
| 200 | { GPRS_LLC_DISC, "DISC" }, |
| 201 | { GPRS_LLC_UA, "UA" }, |
| 202 | { GPRS_LLC_SABM, "SABM" }, |
| 203 | { GPRS_LLC_FRMR, "FRMR" }, |
| 204 | { GPRS_LLC_XID, "XID" }, |
| 205 | { GPRS_LLC_UI, "UI" }, |
| 206 | { 0, NULL } |
| 207 | }; |
| 208 | |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 209 | struct gprs_llc_hdr_parsed { |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 210 | uint8_t sapi; |
| 211 | uint8_t is_cmd:1, |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 212 | ack_req:1, |
| 213 | is_encrypted:1; |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 214 | uint32_t seq_rx; |
| 215 | uint32_t seq_tx; |
| 216 | uint32_t fcs; |
| 217 | uint32_t fcs_calc; |
| 218 | uint8_t *data; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 219 | uint16_t data_len; |
Harald Welte | fa32507 | 2010-06-30 23:15:57 +0200 | [diff] [blame] | 220 | uint16_t crc_length; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 221 | enum gprs_llc_cmd cmd; |
| 222 | }; |
| 223 | |
| 224 | #define LLC_ALLOC_SIZE 16384 |
| 225 | #define UI_HDR_LEN 3 |
| 226 | #define N202 4 |
| 227 | #define CRC24_LENGTH 3 |
| 228 | |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 229 | static int gprs_llc_fcs(uint8_t *data, unsigned int len) |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 230 | { |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 231 | uint32_t fcs_calc; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 232 | |
| 233 | fcs_calc = crc24_calc(INIT_CRC24, data, len); |
| 234 | fcs_calc = ~fcs_calc; |
| 235 | fcs_calc &= 0xffffff; |
| 236 | |
| 237 | return fcs_calc; |
| 238 | } |
| 239 | |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 240 | static void t200_expired(void *data) |
| 241 | { |
| 242 | struct gprs_llc_lle *lle = data; |
| 243 | |
| 244 | /* 8.5.1.3: Expiry of T200 */ |
| 245 | |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 246 | if (lle->retrans_ctr >= lle->params.n200) { |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 247 | /* FIXME: LLGM-STATUS-IND, LL-RELEASE-IND/CNF */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 248 | lle->state = GPRS_LLES_ASSIGNED_ADM; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 249 | } |
| 250 | |
| 251 | switch (lle->state) { |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 252 | case GPRS_LLES_LOCAL_EST: |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 253 | /* FIXME: retransmit SABM */ |
| 254 | /* FIXME: re-start T200 */ |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 255 | lle->retrans_ctr++; |
| 256 | break; |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 257 | case GPRS_LLES_LOCAL_REL: |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 258 | /* FIXME: retransmit DISC */ |
| 259 | /* FIXME: re-start T200 */ |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 260 | lle->retrans_ctr++; |
| 261 | break; |
| 262 | } |
| 263 | |
| 264 | } |
| 265 | |
| 266 | static void t201_expired(void *data) |
| 267 | { |
| 268 | struct gprs_llc_lle *lle = data; |
| 269 | |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 270 | if (lle->retrans_ctr < lle->params.n200) { |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 271 | /* FIXME: transmit apropriate supervisory frame (8.6.4.1) */ |
| 272 | /* FIXME: set timer T201 */ |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 273 | lle->retrans_ctr++; |
| 274 | } |
| 275 | } |
| 276 | |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 277 | int gprs_llc_tx_u(struct msgb *msg, uint8_t sapi, int command, |
| 278 | enum gprs_llc_u_cmd u_cmd, int pf_bit) |
| 279 | { |
| 280 | uint8_t *fcs, *llch; |
| 281 | uint8_t addr, ctrl; |
| 282 | uint32_t fcs_calc; |
| 283 | |
| 284 | /* Identifiers from UP: (TLLI, SAPI) + (BVCI, NSEI) */ |
| 285 | |
| 286 | /* Address Field */ |
| 287 | addr = sapi & 0xf; |
| 288 | if (command) |
| 289 | addr |= 0x40; |
| 290 | |
| 291 | /* 6.3 Figure 8 */ |
| 292 | ctrl = 0xe0 | u_cmd; |
| 293 | if (pf_bit) |
| 294 | ctrl |= 0x10; |
| 295 | |
| 296 | /* prepend LLC UI header */ |
| 297 | llch = msgb_push(msg, 2); |
| 298 | llch[0] = addr; |
| 299 | llch[1] = ctrl; |
| 300 | |
| 301 | /* append FCS to end of frame */ |
| 302 | fcs = msgb_put(msg, 3); |
| 303 | fcs_calc = gprs_llc_fcs(llch, fcs - llch); |
| 304 | fcs[0] = fcs_calc & 0xff; |
| 305 | fcs[1] = (fcs_calc >> 8) & 0xff; |
| 306 | fcs[2] = (fcs_calc >> 16) & 0xff; |
| 307 | |
| 308 | /* Identifiers passed down: (BVCI, NSEI) */ |
| 309 | |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 310 | /* Send BSSGP-DL-UNITDATA.req */ |
Harald Welte | cca80c9 | 2010-05-31 22:12:30 +0200 | [diff] [blame] | 311 | return gprs_bssgp_tx_dl_ud(msg, NULL); |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 312 | } |
| 313 | |
| 314 | /* Send XID response to LLE */ |
Harald Welte | ac687be | 2011-10-16 18:49:05 +0200 | [diff] [blame] | 315 | static int gprs_llc_tx_xid(struct gprs_llc_lle *lle, struct msgb *msg, |
| 316 | int command) |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 317 | { |
| 318 | /* copy identifiers from LLE to ensure lower layers can route */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 319 | msgb_tlli(msg) = lle->llme->tlli; |
| 320 | msgb_bvci(msg) = lle->llme->bvci; |
| 321 | msgb_nsei(msg) = lle->llme->nsei; |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 322 | |
Harald Welte | ac687be | 2011-10-16 18:49:05 +0200 | [diff] [blame] | 323 | return gprs_llc_tx_u(msg, lle->sapi, command, GPRS_LLC_U_XID, 1); |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 324 | } |
| 325 | |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 326 | /* Transmit a UI frame over the given SAPI */ |
Harald Welte | cca80c9 | 2010-05-31 22:12:30 +0200 | [diff] [blame] | 327 | int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command, |
| 328 | void *mmctx) |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 329 | { |
Harald Welte | a6e3270 | 2010-05-02 11:19:37 +0200 | [diff] [blame] | 330 | struct gprs_llc_lle *lle; |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 331 | uint8_t *fcs, *llch; |
| 332 | uint8_t addr, ctrl[2]; |
| 333 | uint32_t fcs_calc; |
| 334 | uint16_t nu = 0; |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 335 | uint32_t oc; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 336 | |
Harald Welte | a6e3270 | 2010-05-02 11:19:37 +0200 | [diff] [blame] | 337 | /* Identifiers from UP: (TLLI, SAPI) + (BVCI, NSEI) */ |
| 338 | |
| 339 | /* look-up or create the LL Entity for this (TLLI, SAPI) tuple */ |
| 340 | lle = lle_by_tlli_sapi(msgb_tlli(msg), sapi); |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 341 | if (!lle) { |
| 342 | struct gprs_llc_llme *llme; |
Harald Welte | 66d062a | 2010-12-26 10:39:26 +0100 | [diff] [blame] | 343 | LOGP(DLLC, LOGL_ERROR, "LLC TX: unknown TLLI 0x%08x, " |
| 344 | "creating LLME on the fly\n", msgb_tlli(msg)); |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 345 | llme = llme_alloc(msgb_tlli(msg)); |
| 346 | lle = &llme->lle[sapi]; |
| 347 | } |
Harald Welte | df270ad | 2010-06-03 07:11:04 +0200 | [diff] [blame] | 348 | |
| 349 | if (msg->len > lle->params.n201_u) { |
| 350 | LOGP(DLLC, LOGL_ERROR, "Cannot Tx %u bytes (N201-U=%u)\n", |
| 351 | msg->len, lle->params.n201_u); |
| 352 | return -EFBIG; |
| 353 | } |
| 354 | |
Harald Welte | a6e3270 | 2010-05-02 11:19:37 +0200 | [diff] [blame] | 355 | /* Update LLE's (BVCI, NSEI) tuple */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 356 | lle->llme->bvci = msgb_bvci(msg); |
| 357 | lle->llme->nsei = msgb_nsei(msg); |
Harald Welte | a6e3270 | 2010-05-02 11:19:37 +0200 | [diff] [blame] | 358 | |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 359 | /* Obtain current values for N(u) and OC */ |
Harald Welte | 02343f9 | 2010-05-30 21:51:58 +0200 | [diff] [blame] | 360 | nu = lle->vu_send; |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 361 | oc = lle->oc_ui_send; |
| 362 | /* Increment V(U) */ |
Harald Welte | 02343f9 | 2010-05-30 21:51:58 +0200 | [diff] [blame] | 363 | lle->vu_send = (lle->vu_send + 1) % 512; |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 364 | /* Increment Overflow Counter, if needed */ |
| 365 | if ((lle->vu_send + 1) / 512) |
| 366 | lle->oc_ui_send += 512; |
Harald Welte | 02343f9 | 2010-05-30 21:51:58 +0200 | [diff] [blame] | 367 | |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 368 | /* Address Field */ |
| 369 | addr = sapi & 0xf; |
| 370 | if (command) |
| 371 | addr |= 0x40; |
| 372 | |
| 373 | /* Control Field */ |
| 374 | ctrl[0] = 0xc0; |
| 375 | ctrl[0] |= nu >> 6; |
| 376 | ctrl[1] = (nu << 2) & 0xfc; |
| 377 | ctrl[1] |= 0x01; /* Protected Mode */ |
| 378 | |
| 379 | /* prepend LLC UI header */ |
| 380 | llch = msgb_push(msg, 3); |
| 381 | llch[0] = addr; |
| 382 | llch[1] = ctrl[0]; |
| 383 | llch[2] = ctrl[1]; |
| 384 | |
| 385 | /* append FCS to end of frame */ |
| 386 | fcs = msgb_put(msg, 3); |
| 387 | fcs_calc = gprs_llc_fcs(llch, fcs - llch); |
| 388 | fcs[0] = fcs_calc & 0xff; |
| 389 | fcs[1] = (fcs_calc >> 8) & 0xff; |
| 390 | fcs[2] = (fcs_calc >> 16) & 0xff; |
| 391 | |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 392 | /* encrypt information field + FCS, if needed! */ |
| 393 | if (lle->llme->algo != GPRS_ALGO_GEA0) { |
| 394 | uint32_t iov_ui = 0; /* FIXME: randomly select for TLLI */ |
| 395 | uint16_t crypt_len = (fcs + 3) - (llch + 3); |
| 396 | uint8_t cipher_out[GSM0464_CIPH_MAX_BLOCK]; |
| 397 | uint32_t iv; |
| 398 | int rc, i; |
| 399 | uint64_t kc = *(uint64_t *)&lle->llme->kc; |
| 400 | |
| 401 | /* Compute the 'Input' Paraemeter */ |
| 402 | iv = gprs_cipher_gen_input_ui(iov_ui, sapi, nu, oc); |
| 403 | |
| 404 | /* Compute the keystream that we need to XOR with the data */ |
| 405 | rc = gprs_cipher_run(cipher_out, crypt_len, lle->llme->algo, |
| 406 | kc, iv, GPRS_CIPH_SGSN2MS); |
| 407 | if (rc < 0) { |
| 408 | LOGP(DLLC, LOGL_ERROR, "Error crypting UI frame: %d\n", rc); |
| 409 | return rc; |
| 410 | } |
| 411 | |
| 412 | /* XOR the cipher output with the information field + FCS */ |
| 413 | for (i = 0; i < crypt_len; i++) |
| 414 | *(llch + 3 + i) ^= cipher_out[i]; |
| 415 | |
| 416 | /* Mark frame as encrypted */ |
| 417 | ctrl[1] |= 0x02; |
| 418 | } |
| 419 | |
Harald Welte | a6e3270 | 2010-05-02 11:19:37 +0200 | [diff] [blame] | 420 | /* Identifiers passed down: (BVCI, NSEI) */ |
| 421 | |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 422 | /* Send BSSGP-DL-UNITDATA.req */ |
Harald Welte | cca80c9 | 2010-05-31 22:12:30 +0200 | [diff] [blame] | 423 | return gprs_bssgp_tx_dl_ud(msg, mmctx); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 424 | } |
| 425 | |
Harald Welte | ac687be | 2011-10-16 18:49:05 +0200 | [diff] [blame] | 426 | /* According to 6.4.1.6 / Figure 11 */ |
| 427 | static int msgb_put_xid_par(struct msgb *msg, uint8_t type, uint8_t length, uint8_t *data) |
| 428 | { |
| 429 | uint8_t header_len = 1; |
| 430 | uint8_t *cur; |
| 431 | |
| 432 | /* type is a 5-bit field... */ |
| 433 | if (type > 0x1f) |
| 434 | return -EINVAL; |
| 435 | |
| 436 | if (length > 3) |
| 437 | header_len = 2; |
| 438 | |
| 439 | cur = msgb_put(msg, length + header_len); |
| 440 | |
| 441 | /* build the header without or with XL bit */ |
| 442 | if (length <= 3) { |
| 443 | *cur++ = (type << 2) | (length & 3); |
| 444 | } else { |
| 445 | *cur++ = 0x80 | (type << 2) | (length >> 6); |
| 446 | *cur++ = (length << 2); |
| 447 | } |
| 448 | |
| 449 | /* copy over the payload of the parameter*/ |
| 450 | memcpy(cur, data, length); |
| 451 | |
| 452 | return length + header_len; |
| 453 | } |
| 454 | |
| 455 | static void rx_llc_xid(struct gprs_llc_lle *lle, |
| 456 | struct gprs_llc_hdr_parsed *gph) |
| 457 | { |
| 458 | /* FIXME: 8.5.3.3: check if XID is invalid */ |
| 459 | if (gph->is_cmd) { |
| 460 | /* FIXME: implement XID negotiation using SNDCP */ |
| 461 | struct msgb *resp; |
| 462 | uint8_t *xid; |
| 463 | resp = msgb_alloc_headroom(4096, 1024, "LLC_XID"); |
| 464 | xid = msgb_put(resp, gph->data_len); |
| 465 | memcpy(xid, gph->data, gph->data_len); |
| 466 | gprs_llc_tx_xid(lle, resp, 0); |
| 467 | } else { |
| 468 | /* FIXME: if we had sent a XID reset, send |
| 469 | * LLGMM-RESET.conf to GMM */ |
| 470 | /* FIXME: implement XID negotiation using SNDCP */ |
| 471 | } |
| 472 | } |
| 473 | |
Holger Hans Peter Freyther | 6f8867b | 2010-05-23 21:35:25 +0800 | [diff] [blame] | 474 | static void gprs_llc_hdr_dump(struct gprs_llc_hdr_parsed *gph) |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 475 | { |
Sylvain Munaut | 1a3b9c9 | 2010-07-03 22:03:02 +0200 | [diff] [blame] | 476 | DEBUGP(DLLC, "LLC SAPI=%u %c %c FCS=0x%06x", |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 477 | gph->sapi, gph->is_cmd ? 'C' : 'R', gph->ack_req ? 'A' : ' ', |
Sylvain Munaut | 1a3b9c9 | 2010-07-03 22:03:02 +0200 | [diff] [blame] | 478 | gph->fcs); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 479 | |
| 480 | if (gph->cmd) |
Harald Welte | 366c204 | 2010-05-18 12:31:50 +0200 | [diff] [blame] | 481 | DEBUGPC(DLLC, "CMD=%s ", get_value_string(llc_cmd_strs, gph->cmd)); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 482 | |
| 483 | if (gph->data) |
Harald Welte | 24b7887 | 2010-05-13 19:47:50 +0200 | [diff] [blame] | 484 | DEBUGPC(DLLC, "DATA "); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 485 | |
Harald Welte | 24b7887 | 2010-05-13 19:47:50 +0200 | [diff] [blame] | 486 | DEBUGPC(DLLC, "\n"); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 487 | } |
| 488 | static int gprs_llc_hdr_rx(struct gprs_llc_hdr_parsed *gph, |
| 489 | struct gprs_llc_lle *lle) |
| 490 | { |
| 491 | switch (gph->cmd) { |
| 492 | case GPRS_LLC_SABM: /* Section 6.4.1.1 */ |
| 493 | lle->v_sent = lle->v_ack = lle->v_recv = 0; |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 494 | if (lle->state == GPRS_LLES_ASSIGNED_ADM) { |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 495 | /* start re-establishment (8.7.1) */ |
| 496 | } |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 497 | lle->state = GPRS_LLES_REMOTE_EST; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 498 | /* FIXME: Send UA */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 499 | lle->state = GPRS_LLES_ABM; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 500 | /* FIXME: process data */ |
| 501 | break; |
| 502 | case GPRS_LLC_DISC: /* Section 6.4.1.2 */ |
| 503 | /* FIXME: Send UA */ |
| 504 | /* terminate ABM */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 505 | lle->state = GPRS_LLES_ASSIGNED_ADM; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 506 | break; |
| 507 | case GPRS_LLC_UA: /* Section 6.4.1.3 */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 508 | if (lle->state == GPRS_LLES_LOCAL_EST) |
| 509 | lle->state = GPRS_LLES_ABM; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 510 | break; |
| 511 | case GPRS_LLC_DM: /* Section 6.4.1.4: ABM cannot be performed */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 512 | if (lle->state == GPRS_LLES_LOCAL_EST) |
| 513 | lle->state = GPRS_LLES_ASSIGNED_ADM; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 514 | break; |
| 515 | case GPRS_LLC_FRMR: /* Section 6.4.1.5 */ |
| 516 | break; |
| 517 | case GPRS_LLC_XID: /* Section 6.4.1.6 */ |
Harald Welte | ac687be | 2011-10-16 18:49:05 +0200 | [diff] [blame] | 518 | rx_llc_xid(lle, gph); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 519 | break; |
Harald Welte | d0e36dc | 2010-06-01 18:28:10 +0200 | [diff] [blame] | 520 | case GPRS_LLC_UI: |
Holger Hans Peter Freyther | 6721a08 | 2011-06-23 17:53:27 -0400 | [diff] [blame] | 521 | if (gprs_llc_is_retransmit(gph->seq_tx, lle->vu_recv)) { |
| 522 | LOGP(DLLC, LOGL_NOTICE, |
| 523 | "TLLI=%08x dropping UI, N(U=%d) not in window V(URV(UR:%d).\n", |
Holger Hans Peter Freyther | 1b5b66c | 2010-06-23 09:48:25 +0800 | [diff] [blame] | 524 | lle->llme ? lle->llme->tlli : -1, |
Harald Welte | d0e36dc | 2010-06-01 18:28:10 +0200 | [diff] [blame] | 525 | gph->seq_tx, lle->vu_recv); |
| 526 | return -EIO; |
| 527 | } |
| 528 | /* Increment the sequence number that we expect in the next frame */ |
| 529 | lle->vu_recv = (gph->seq_tx + 1) % 512; |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 530 | /* Increment Overflow Counter */ |
| 531 | if ((gph->seq_tx + 1) / 512) |
| 532 | lle->oc_ui_recv += 512; |
Harald Welte | d0e36dc | 2010-06-01 18:28:10 +0200 | [diff] [blame] | 533 | break; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 534 | } |
| 535 | |
| 536 | return 0; |
| 537 | } |
| 538 | |
| 539 | /* parse a GPRS LLC header, also check for invalid frames */ |
| 540 | static int gprs_llc_hdr_parse(struct gprs_llc_hdr_parsed *ghp, |
Holger Hans Peter Freyther | 6f26151 | 2010-05-23 21:43:57 +0800 | [diff] [blame] | 541 | uint8_t *llc_hdr, int len) |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 542 | { |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 543 | uint8_t *ctrl = llc_hdr+1; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 544 | |
| 545 | if (len <= CRC24_LENGTH) |
| 546 | return -EIO; |
| 547 | |
Harald Welte | fa32507 | 2010-06-30 23:15:57 +0200 | [diff] [blame] | 548 | ghp->crc_length = len - CRC24_LENGTH; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 549 | |
| 550 | ghp->ack_req = 0; |
| 551 | |
| 552 | /* Section 5.5: FCS */ |
| 553 | ghp->fcs = *(llc_hdr + len - 3); |
| 554 | ghp->fcs |= *(llc_hdr + len - 2) << 8; |
| 555 | ghp->fcs |= *(llc_hdr + len - 1) << 16; |
| 556 | |
| 557 | /* Section 6.2.1: invalid PD field */ |
| 558 | if (llc_hdr[0] & 0x80) |
| 559 | return -EIO; |
| 560 | |
| 561 | /* This only works for the MS->SGSN direction */ |
| 562 | if (llc_hdr[0] & 0x40) |
| 563 | ghp->is_cmd = 0; |
| 564 | else |
| 565 | ghp->is_cmd = 1; |
| 566 | |
| 567 | ghp->sapi = llc_hdr[0] & 0xf; |
| 568 | |
| 569 | /* Section 6.2.3: check for reserved SAPI */ |
| 570 | switch (ghp->sapi) { |
| 571 | case 0: |
| 572 | case 4: |
| 573 | case 6: |
| 574 | case 0xa: |
| 575 | case 0xc: |
| 576 | case 0xd: |
| 577 | case 0xf: |
| 578 | return -EINVAL; |
| 579 | } |
| 580 | |
| 581 | if ((ctrl[0] & 0x80) == 0) { |
| 582 | /* I (Information transfer + Supervisory) format */ |
Harald Welte | d85d9a9 | 2010-05-02 11:26:34 +0200 | [diff] [blame] | 583 | uint8_t k; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 584 | |
| 585 | ghp->data = ctrl + 3; |
| 586 | |
| 587 | if (ctrl[0] & 0x40) |
| 588 | ghp->ack_req = 1; |
| 589 | |
| 590 | ghp->seq_tx = (ctrl[0] & 0x1f) << 4; |
| 591 | ghp->seq_tx |= (ctrl[1] >> 4); |
| 592 | |
| 593 | ghp->seq_rx = (ctrl[1] & 0x7) << 6; |
| 594 | ghp->seq_rx |= (ctrl[2] >> 2); |
| 595 | |
| 596 | switch (ctrl[2] & 0x03) { |
| 597 | case 0: |
| 598 | ghp->cmd = GPRS_LLC_RR; |
| 599 | break; |
| 600 | case 1: |
| 601 | ghp->cmd = GPRS_LLC_ACK; |
| 602 | break; |
| 603 | case 2: |
| 604 | ghp->cmd = GPRS_LLC_RNR; |
| 605 | break; |
| 606 | case 3: |
| 607 | ghp->cmd = GPRS_LLC_SACK; |
| 608 | k = ctrl[3] & 0x1f; |
| 609 | ghp->data += 1 + k; |
| 610 | break; |
| 611 | } |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 612 | ghp->data_len = (llc_hdr + len - 3) - ghp->data; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 613 | } else if ((ctrl[0] & 0xc0) == 0x80) { |
| 614 | /* S (Supervisory) format */ |
| 615 | ghp->data = NULL; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 616 | ghp->data_len = 0; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 617 | |
| 618 | if (ctrl[0] & 0x20) |
| 619 | ghp->ack_req = 1; |
| 620 | ghp->seq_rx = (ctrl[0] & 0x7) << 6; |
| 621 | ghp->seq_rx |= (ctrl[1] >> 2); |
| 622 | |
| 623 | switch (ctrl[1] & 0x03) { |
| 624 | case 0: |
| 625 | ghp->cmd = GPRS_LLC_RR; |
| 626 | break; |
| 627 | case 1: |
| 628 | ghp->cmd = GPRS_LLC_ACK; |
| 629 | break; |
| 630 | case 2: |
| 631 | ghp->cmd = GPRS_LLC_RNR; |
| 632 | break; |
| 633 | case 3: |
| 634 | ghp->cmd = GPRS_LLC_SACK; |
| 635 | break; |
| 636 | } |
| 637 | } else if ((ctrl[0] & 0xe0) == 0xc0) { |
| 638 | /* UI (Unconfirmed Inforamtion) format */ |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 639 | ghp->cmd = GPRS_LLC_UI; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 640 | ghp->data = ctrl + 2; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 641 | ghp->data_len = (llc_hdr + len - 3) - ghp->data; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 642 | |
| 643 | ghp->seq_tx = (ctrl[0] & 0x7) << 6; |
| 644 | ghp->seq_tx |= (ctrl[1] >> 2); |
| 645 | if (ctrl[1] & 0x02) { |
| 646 | ghp->is_encrypted = 1; |
| 647 | /* FIXME: encryption */ |
| 648 | } |
| 649 | if (ctrl[1] & 0x01) { |
| 650 | /* FCS over hdr + all inf fields */ |
| 651 | } else { |
| 652 | /* FCS over hdr + N202 octets (4) */ |
Harald Welte | fa32507 | 2010-06-30 23:15:57 +0200 | [diff] [blame] | 653 | if (ghp->crc_length > UI_HDR_LEN + N202) |
| 654 | ghp->crc_length = UI_HDR_LEN + N202; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 655 | } |
| 656 | } else { |
| 657 | /* U (Unnumbered) format: 1 1 1 P/F M4 M3 M2 M1 */ |
| 658 | ghp->data = NULL; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 659 | ghp->data_len = 0; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 660 | |
| 661 | switch (ctrl[0] & 0xf) { |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 662 | case GPRS_LLC_U_NULL_CMD: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 663 | ghp->cmd = GPRS_LLC_NULL; |
| 664 | break; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 665 | case GPRS_LLC_U_DM_RESP: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 666 | ghp->cmd = GPRS_LLC_DM; |
| 667 | break; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 668 | case GPRS_LLC_U_DISC_CMD: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 669 | ghp->cmd = GPRS_LLC_DISC; |
| 670 | break; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 671 | case GPRS_LLC_U_UA_RESP: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 672 | ghp->cmd = GPRS_LLC_UA; |
| 673 | break; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 674 | case GPRS_LLC_U_SABM_CMD: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 675 | ghp->cmd = GPRS_LLC_SABM; |
| 676 | break; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 677 | case GPRS_LLC_U_FRMR_RESP: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 678 | ghp->cmd = GPRS_LLC_FRMR; |
| 679 | break; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 680 | case GPRS_LLC_U_XID: |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 681 | ghp->cmd = GPRS_LLC_XID; |
Harald Welte | 9f14f98 | 2010-05-03 13:25:07 +0200 | [diff] [blame] | 682 | ghp->data = ctrl + 1; |
| 683 | ghp->data_len = (llc_hdr + len - 3) - ghp->data; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 684 | break; |
| 685 | default: |
| 686 | return -EIO; |
| 687 | } |
| 688 | } |
| 689 | |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 690 | /* FIXME: parse sack frame */ |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 691 | if (ghp->cmd == GPRS_LLC_SACK) { |
Harald Welte | e349736 | 2010-05-13 19:49:06 +0200 | [diff] [blame] | 692 | LOGP(DLLC, LOGL_NOTICE, "Unsupported SACK frame\n"); |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 693 | return -EIO; |
| 694 | } |
| 695 | |
| 696 | return 0; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 697 | } |
| 698 | |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 699 | /* receive an incoming LLC PDU (BSSGP-UL-UNITDATA-IND, 7.2.4.2) */ |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 700 | int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv) |
| 701 | { |
Harald Welte | 7316440 | 2010-05-02 09:50:42 +0200 | [diff] [blame] | 702 | struct bssgp_ud_hdr *udh = (struct bssgp_ud_hdr *) msgb_bssgph(msg); |
Holger Hans Peter Freyther | f9839f6 | 2011-10-14 23:42:13 +0200 | [diff] [blame] | 703 | struct gprs_llc_hdr *lh = (struct gprs_llc_hdr *) msgb_llch(msg); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 704 | struct gprs_llc_hdr_parsed llhp; |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 705 | struct gprs_llc_lle *lle; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 706 | int rc = 0; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 707 | |
Harald Welte | 2351f1f | 2010-05-02 11:54:55 +0200 | [diff] [blame] | 708 | /* Identifiers from DOWN: NSEI, BVCI, TLLI */ |
| 709 | |
Holger Hans Peter Freyther | 510ae72 | 2010-05-23 21:33:57 +0800 | [diff] [blame] | 710 | memset(&llhp, 0, sizeof(llhp)); |
Holger Hans Peter Freyther | 6f26151 | 2010-05-23 21:43:57 +0800 | [diff] [blame] | 711 | rc = gprs_llc_hdr_parse(&llhp, (uint8_t *) lh, TLVP_LEN(tv, BSSGP_IE_LLC_PDU)); |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 712 | gprs_llc_hdr_dump(&llhp); |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 713 | if (rc < 0) { |
Harald Welte | e349736 | 2010-05-13 19:49:06 +0200 | [diff] [blame] | 714 | LOGP(DLLC, LOGL_NOTICE, "Error during LLC header parsing\n"); |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 715 | return rc; |
| 716 | } |
| 717 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 718 | switch (gprs_tlli_type(msgb_tlli(msg))) { |
| 719 | case TLLI_LOCAL: |
| 720 | case TLLI_FOREIGN: |
| 721 | case TLLI_RANDOM: |
| 722 | case TLLI_AUXILIARY: |
| 723 | break; |
| 724 | default: |
| 725 | LOGP(DLLC, LOGL_ERROR, |
| 726 | "Discarding frame with strange TLLI type\n"); |
| 727 | break; |
| 728 | } |
| 729 | |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 730 | /* find the LLC Entity for this TLLI+SAPI tuple */ |
| 731 | lle = lle_by_tlli_sapi(msgb_tlli(msg), llhp.sapi); |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 732 | |
| 733 | /* 7.2.1.1 LLC belonging to unassigned TLLI+SAPI shall be discarded, |
| 734 | * except UID and XID frames with SAPI=1 */ |
Harald Welte | 4b7d1de | 2010-05-18 12:45:08 +0200 | [diff] [blame] | 735 | if (!lle) { |
| 736 | if (llhp.sapi == GPRS_SAPI_GMM && |
| 737 | (llhp.cmd == GPRS_LLC_XID || llhp.cmd == GPRS_LLC_UI)) { |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 738 | struct gprs_llc_llme *llme; |
Harald Welte | 4b7d1de | 2010-05-18 12:45:08 +0200 | [diff] [blame] | 739 | /* FIXME: don't use the TLLI but the 0xFFFF unassigned? */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 740 | llme = llme_alloc(msgb_tlli(msg)); |
Dieter Spaar | 9770bd4 | 2011-07-27 23:38:46 +0200 | [diff] [blame] | 741 | LOGP(DLLC, LOGL_DEBUG, "LLC RX: unknown TLLI 0x%08x, " |
Harald Welte | 66d062a | 2010-12-26 10:39:26 +0100 | [diff] [blame] | 742 | "creating LLME on the fly\n", msgb_tlli(msg)); |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 743 | lle = &llme->lle[llhp.sapi]; |
Harald Welte | 4b7d1de | 2010-05-18 12:45:08 +0200 | [diff] [blame] | 744 | } else { |
| 745 | LOGP(DLLC, LOGL_NOTICE, |
| 746 | "unknown TLLI/SAPI: Silently dropping\n"); |
| 747 | return 0; |
| 748 | } |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 749 | } |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 750 | |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 751 | /* decrypt information field + FCS, if needed! */ |
| 752 | if (llhp.is_encrypted) { |
| 753 | uint32_t iov_ui = 0; /* FIXME: randomly select for TLLI */ |
| 754 | uint16_t crypt_len = llhp.data_len + 3; |
| 755 | uint8_t cipher_out[GSM0464_CIPH_MAX_BLOCK]; |
| 756 | uint32_t iv; |
| 757 | uint64_t kc = *(uint64_t *)&lle->llme->kc; |
| 758 | int rc, i; |
| 759 | |
| 760 | if (lle->llme->algo == GPRS_ALGO_GEA0) { |
| 761 | LOGP(DLLC, LOGL_NOTICE, "encrypted frame for LLC that " |
| 762 | "has no KC/Algo! Dropping.\n"); |
| 763 | return 0; |
| 764 | } |
| 765 | |
| 766 | iv = gprs_cipher_gen_input_ui(iov_ui, lle->sapi, llhp.seq_tx, |
| 767 | lle->oc_ui_recv); |
| 768 | rc = gprs_cipher_run(cipher_out, crypt_len, lle->llme->algo, |
| 769 | kc, iv, GPRS_CIPH_MS2SGSN); |
| 770 | if (rc < 0) { |
| 771 | LOGP(DLLC, LOGL_ERROR, "Error decrypting frame: %d\n", |
| 772 | rc); |
| 773 | return rc; |
| 774 | } |
| 775 | |
| 776 | /* XOR the cipher output with the information field + FCS */ |
| 777 | for (i = 0; i < crypt_len; i++) |
| 778 | *(llhp.data + i) ^= cipher_out[i]; |
| 779 | } else { |
| 780 | if (lle->llme->algo != GPRS_ALGO_GEA0) { |
| 781 | LOGP(DLLC, LOGL_NOTICE, "unencrypted frame for LLC " |
| 782 | "that is supposed to be encrypted. Dropping.\n"); |
| 783 | return 0; |
| 784 | } |
| 785 | } |
| 786 | |
| 787 | /* We have to do the FCS check _after_ decryption */ |
Harald Welte | fa32507 | 2010-06-30 23:15:57 +0200 | [diff] [blame] | 788 | llhp.fcs_calc = gprs_llc_fcs((uint8_t *)lh, llhp.crc_length); |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 789 | if (llhp.fcs != llhp.fcs_calc) { |
| 790 | LOGP(DLLC, LOGL_INFO, "Dropping frame with invalid FCS\n"); |
| 791 | return -EIO; |
| 792 | } |
| 793 | |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 794 | /* Update LLE's (BVCI, NSEI) tuple */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 795 | lle->llme->bvci = msgb_bvci(msg); |
| 796 | lle->llme->nsei = msgb_nsei(msg); |
Harald Welte | 439fa72 | 2010-05-03 12:28:12 +0200 | [diff] [blame] | 797 | |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 798 | /* Receive and Process the actual LLC frame */ |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 799 | rc = gprs_llc_hdr_rx(&llhp, lle); |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 800 | if (rc < 0) |
| 801 | return rc; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 802 | |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 803 | /* llhp.data is only set when we need to send LL_[UNIT]DATA_IND up */ |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 804 | if (llhp.data) { |
Harald Welte | cf3c414 | 2010-04-30 16:33:12 +0200 | [diff] [blame] | 805 | msgb_gmmh(msg) = llhp.data; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 806 | switch (llhp.sapi) { |
| 807 | case GPRS_SAPI_GMM: |
Harald Welte | febc426 | 2010-05-13 19:22:55 +0200 | [diff] [blame] | 808 | /* send LL_UNITDATA_IND to GMM */ |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 809 | rc = gsm0408_gprs_rcvmsg(msg, lle->llme); |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 810 | break; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 811 | case GPRS_SAPI_SNDCP3: |
| 812 | case GPRS_SAPI_SNDCP5: |
| 813 | case GPRS_SAPI_SNDCP9: |
| 814 | case GPRS_SAPI_SNDCP11: |
Harald Welte | d0e36dc | 2010-06-01 18:28:10 +0200 | [diff] [blame] | 815 | /* send LL_DATA_IND/LL_UNITDATA_IND to SNDCP */ |
| 816 | rc = sndcp_llunitdata_ind(msg, lle, llhp.data, llhp.data_len); |
| 817 | break; |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 818 | case GPRS_SAPI_SMS: |
| 819 | /* FIXME */ |
Harald Welte | d0e36dc | 2010-06-01 18:28:10 +0200 | [diff] [blame] | 820 | case GPRS_SAPI_TOM2: |
| 821 | case GPRS_SAPI_TOM8: |
| 822 | /* FIXME: send LL_DATA_IND/LL_UNITDATA_IND to TOM */ |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 823 | default: |
Harald Welte | 24b7887 | 2010-05-13 19:47:50 +0200 | [diff] [blame] | 824 | LOGP(DLLC, LOGL_NOTICE, "Unsupported SAPI %u\n", llhp.sapi); |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 825 | rc = -EINVAL; |
| 826 | break; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 827 | } |
| 828 | } |
| 829 | |
Harald Welte | c14e582 | 2010-05-02 09:28:11 +0200 | [diff] [blame] | 830 | return rc; |
Harald Welte | 75bb820 | 2010-03-14 15:45:01 +0800 | [diff] [blame] | 831 | } |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 832 | |
| 833 | /* 04.64 Chapter 7.2.1.1 LLGMM-ASSIGN */ |
| 834 | int gprs_llgmm_assign(struct gprs_llc_llme *llme, |
| 835 | uint32_t old_tlli, uint32_t new_tlli, |
| 836 | enum gprs_ciph_algo alg, const uint8_t *kc) |
| 837 | { |
| 838 | unsigned int i; |
| 839 | |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 840 | /* Update the crypto parameters */ |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 841 | llme->algo = alg; |
Harald Welte | 82e26e2 | 2010-06-30 23:19:23 +0200 | [diff] [blame] | 842 | if (alg != GPRS_ALGO_GEA0) |
| 843 | memcpy(llme->kc, kc, sizeof(llme->kc)); |
Harald Welte | 222b068 | 2010-06-30 23:07:59 +0200 | [diff] [blame] | 844 | |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 845 | if (old_tlli == 0xffffffff && new_tlli != 0xffffffff) { |
| 846 | /* TLLI Assignment 8.3.1 */ |
| 847 | /* New TLLI shall be assigned and used when (re)transmitting LLC frames */ |
| 848 | /* If old TLLI != 0xffffffff was assigned to LLME, then TLLI |
| 849 | * old is unassigned. Only TLLI new shall be accepted when |
| 850 | * received from peer. */ |
Harald Welte | b3d84a4 | 2010-07-01 11:54:31 +0200 | [diff] [blame] | 851 | if (llme->old_tlli != 0xffffffff) { |
| 852 | llme->old_tlli = 0xffffffff; |
| 853 | llme->tlli = new_tlli; |
| 854 | } else { |
| 855 | /* If TLLI old == 0xffffffff was assigned to LLME, then this is |
| 856 | * TLLI assignmemt according to 8.3.1 */ |
| 857 | llme->old_tlli = 0xffffffff; |
| 858 | llme->tlli = new_tlli; |
| 859 | llme->state = GPRS_LLMS_ASSIGNED; |
| 860 | /* 8.5.3.1 For all LLE's */ |
| 861 | for (i = 0; i < ARRAY_SIZE(llme->lle); i++) { |
| 862 | struct gprs_llc_lle *l = &llme->lle[i]; |
| 863 | l->vu_send = l->vu_recv = 0; |
| 864 | l->retrans_ctr = 0; |
| 865 | l->state = GPRS_LLES_ASSIGNED_ADM; |
| 866 | /* FIXME Set parameters according to table 9 */ |
| 867 | } |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 868 | } |
| 869 | } else if (old_tlli != 0xffffffff && new_tlli != 0xffffffff) { |
| 870 | /* TLLI Change 8.3.2 */ |
| 871 | /* Both TLLI Old and TLLI New are assigned; use New when |
| 872 | * (re)transmitting. Accept toth Old and New on Rx */ |
| 873 | llme->old_tlli = llme->tlli; |
| 874 | llme->tlli = new_tlli; |
| 875 | llme->state = GPRS_LLMS_ASSIGNED; |
| 876 | } else if (old_tlli != 0xffffffff && new_tlli == 0xffffffff) { |
| 877 | /* TLLI Unassignment 8.3.3) */ |
| 878 | llme->tlli = llme->old_tlli = 0; |
| 879 | llme->state = GPRS_LLMS_UNASSIGNED; |
| 880 | for (i = 0; i < ARRAY_SIZE(llme->lle); i++) { |
| 881 | struct gprs_llc_lle *l = &llme->lle[i]; |
| 882 | l->state = GPRS_LLES_UNASSIGNED; |
| 883 | } |
Harald Welte | 7a62a3a | 2010-06-28 22:18:26 +0200 | [diff] [blame] | 884 | llme_free(llme); |
Harald Welte | 75871c7 | 2010-06-01 11:53:01 +0200 | [diff] [blame] | 885 | } else |
| 886 | return -EINVAL; |
| 887 | |
| 888 | return 0; |
| 889 | } |
Harald Welte | 81fb358 | 2010-06-30 19:59:55 +0200 | [diff] [blame] | 890 | |
Harald Welte | ac687be | 2011-10-16 18:49:05 +0200 | [diff] [blame] | 891 | /* Chapter 7.2.1.2 LLGMM-RESET.req */ |
| 892 | int gprs_llgmm_reset(struct gprs_llc_llme *llme) |
| 893 | { |
| 894 | struct msgb *msg = msgb_alloc_headroom(4096, 1024, "LLC_XID"); |
| 895 | int random = rand(); |
| 896 | |
| 897 | /* First XID component must be RESET */ |
| 898 | msgb_put_xid_par(msg, GPRS_LLC_XID_T_RESET, 0, NULL); |
| 899 | /* randomly select new IOV-UI */ |
Harald Welte | ffc1999 | 2011-10-16 18:59:20 +0200 | [diff] [blame] | 900 | msgb_put_xid_par(msg, GPRS_LLC_XID_T_IOV_UI, 4, (uint8_t *) &random); |
Harald Welte | ac687be | 2011-10-16 18:49:05 +0200 | [diff] [blame] | 901 | |
| 902 | /* FIXME: Start T200, wait for XID response */ |
| 903 | return gprs_llc_tx_xid(&llme->lle[1], msg, 1); |
| 904 | } |
| 905 | |
Harald Welte | 81fb358 | 2010-06-30 19:59:55 +0200 | [diff] [blame] | 906 | int gprs_llc_init(const char *cipher_plugin_path) |
| 907 | { |
| 908 | return gprs_cipher_load(cipher_plugin_path); |
| 909 | } |