1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021-2023 Intel Corporation 5 * Author: Luis Carlos Cobo <luisca@cozybit.com> 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/etherdevice.h> 10 #include <linux/unaligned.h> 11 #include "wme.h" 12 #include "mesh.h" 13 14 #define TEST_FRAME_LEN 8192 15 #define MAX_METRIC 0xffffffff 16 #define ARITH_SHIFT 8 17 #define LINK_FAIL_THRESH 95 18 19 #define MAX_PREQ_QUEUE_LEN 64 20 21 static void mesh_queue_preq(struct mesh_path *, u8); 22 23 static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae) 24 { 25 if (ae) 26 offset += 6; 27 return get_unaligned_le32(preq_elem + offset); 28 } 29 30 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae) 31 { 32 if (ae) 33 offset += 6; 34 return get_unaligned_le16(preq_elem + offset); 35 } 36 37 /* HWMP IE processing macros */ 38 #define AE_F (1<<6) 39 #define AE_F_SET(x) (*x & AE_F) 40 #define PREQ_IE_FLAGS(x) (*(x)) 41 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 42 #define PREQ_IE_TTL(x) (*(x + 2)) 43 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 44 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 45 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0) 46 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)) 47 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)) 48 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 49 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 50 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)) 51 52 53 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 54 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 55 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 56 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 57 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x)) 58 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)) 59 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)) 60 #define PREP_IE_TARGET_ADDR(x) (x + 3) 61 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 62 63 #define PERR_IE_TTL(x) (*(x)) 64 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 65 #define PERR_IE_TARGET_ADDR(x) (x + 3) 66 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 67 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) 68 69 #define MSEC_TO_TU(x) (x*1000/1024) 70 #define SN_GT(x, y) ((s32)(y - x) < 0) 71 #define SN_LT(x, y) ((s32)(x - y) < 0) 72 #define MAX_SANE_SN_DELTA 32 73 74 static inline u32 SN_DELTA(u32 x, u32 y) 75 { 76 return x >= y ? x - y : y - x; 77 } 78 79 #define net_traversal_jiffies(s) \ 80 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 81 #define default_lifetime(s) \ 82 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 83 #define min_preq_int_jiff(s) \ 84 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 85 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 86 #define disc_timeout_jiff(s) \ 87 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 88 #define root_path_confirmation_jiffies(s) \ 89 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval) 90 91 enum mpath_frame_type { 92 MPATH_PREQ = 0, 93 MPATH_PREP, 94 MPATH_PERR, 95 MPATH_RANN 96 }; 97 98 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 99 100 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 101 const u8 *orig_addr, u32 orig_sn, 102 u8 target_flags, const u8 *target, 103 u32 target_sn, const u8 *da, 104 u8 hop_count, u8 ttl, 105 u32 lifetime, u32 metric, u32 preq_id, 106 struct ieee80211_sub_if_data *sdata) 107 { 108 struct ieee80211_local *local = sdata->local; 109 struct sk_buff *skb; 110 struct ieee80211_mgmt *mgmt; 111 u8 *pos, ie_len; 112 int hdr_len = offsetofend(struct ieee80211_mgmt, 113 u.action.u.mesh_action); 114 115 skb = dev_alloc_skb(local->tx_headroom + 116 hdr_len + 117 2 + 37); /* max HWMP IE */ 118 if (!skb) 119 return -1; 120 skb_reserve(skb, local->tx_headroom); 121 mgmt = skb_put_zero(skb, hdr_len); 122 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 123 IEEE80211_STYPE_ACTION); 124 125 memcpy(mgmt->da, da, ETH_ALEN); 126 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 127 /* BSSID == SA */ 128 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 129 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 130 mgmt->u.action.u.mesh_action.action_code = 131 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 132 133 switch (action) { 134 case MPATH_PREQ: 135 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target); 136 ie_len = 37; 137 pos = skb_put(skb, 2 + ie_len); 138 *pos++ = WLAN_EID_PREQ; 139 break; 140 case MPATH_PREP: 141 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr); 142 ie_len = 31; 143 pos = skb_put(skb, 2 + ie_len); 144 *pos++ = WLAN_EID_PREP; 145 break; 146 case MPATH_RANN: 147 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr); 148 ie_len = sizeof(struct ieee80211_rann_ie); 149 pos = skb_put(skb, 2 + ie_len); 150 *pos++ = WLAN_EID_RANN; 151 break; 152 default: 153 kfree_skb(skb); 154 return -EOPNOTSUPP; 155 } 156 *pos++ = ie_len; 157 *pos++ = flags; 158 *pos++ = hop_count; 159 *pos++ = ttl; 160 if (action == MPATH_PREP) { 161 memcpy(pos, target, ETH_ALEN); 162 pos += ETH_ALEN; 163 put_unaligned_le32(target_sn, pos); 164 pos += 4; 165 } else { 166 if (action == MPATH_PREQ) { 167 put_unaligned_le32(preq_id, pos); 168 pos += 4; 169 } 170 memcpy(pos, orig_addr, ETH_ALEN); 171 pos += ETH_ALEN; 172 put_unaligned_le32(orig_sn, pos); 173 pos += 4; 174 } 175 put_unaligned_le32(lifetime, pos); /* interval for RANN */ 176 pos += 4; 177 put_unaligned_le32(metric, pos); 178 pos += 4; 179 if (action == MPATH_PREQ) { 180 *pos++ = 1; /* destination count */ 181 *pos++ = target_flags; 182 memcpy(pos, target, ETH_ALEN); 183 pos += ETH_ALEN; 184 put_unaligned_le32(target_sn, pos); 185 pos += 4; 186 } else if (action == MPATH_PREP) { 187 memcpy(pos, orig_addr, ETH_ALEN); 188 pos += ETH_ALEN; 189 put_unaligned_le32(orig_sn, pos); 190 pos += 4; 191 } 192 193 ieee80211_tx_skb(sdata, skb); 194 return 0; 195 } 196 197 198 /* Headroom is not adjusted. Caller should ensure that skb has sufficient 199 * headroom in case the frame is encrypted. */ 200 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, 201 struct sk_buff *skb) 202 { 203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 204 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 205 206 skb_reset_mac_header(skb); 207 skb_reset_network_header(skb); 208 skb_reset_transport_header(skb); 209 210 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ 211 skb_set_queue_mapping(skb, IEEE80211_AC_VO); 212 skb->priority = 7; 213 214 info->control.vif = &sdata->vif; 215 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING; 216 ieee80211_set_qos_hdr(sdata, skb); 217 ieee80211_mps_set_frame_flags(sdata, NULL, hdr); 218 } 219 220 /** 221 * mesh_path_error_tx - Sends a PERR mesh management frame 222 * 223 * @sdata: local mesh subif 224 * @ttl: allowed remaining hops 225 * @target: broken destination 226 * @target_sn: SN of the broken destination 227 * @target_rcode: reason code for this PERR 228 * @ra: node this frame is addressed to 229 * 230 * Note: This function may be called with driver locks taken that the driver 231 * also acquires in the TX path. To avoid a deadlock we don't transmit the 232 * frame directly but add it to the pending queue instead. 233 * 234 * Returns: 0 on success 235 */ 236 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata, 237 u8 ttl, const u8 *target, u32 target_sn, 238 u16 target_rcode, const u8 *ra) 239 { 240 struct ieee80211_local *local = sdata->local; 241 struct sk_buff *skb; 242 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 243 struct ieee80211_mgmt *mgmt; 244 u8 *pos, ie_len; 245 int hdr_len = offsetofend(struct ieee80211_mgmt, 246 u.action.u.mesh_action); 247 248 if (time_before(jiffies, ifmsh->next_perr)) 249 return -EAGAIN; 250 251 skb = dev_alloc_skb(local->tx_headroom + 252 IEEE80211_ENCRYPT_HEADROOM + 253 IEEE80211_ENCRYPT_TAILROOM + 254 hdr_len + 255 2 + 15 /* PERR IE */); 256 if (!skb) 257 return -1; 258 skb_reserve(skb, local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM); 259 mgmt = skb_put_zero(skb, hdr_len); 260 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 261 IEEE80211_STYPE_ACTION); 262 263 memcpy(mgmt->da, ra, ETH_ALEN); 264 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 265 /* BSSID == SA */ 266 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 267 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 268 mgmt->u.action.u.mesh_action.action_code = 269 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 270 ie_len = 15; 271 pos = skb_put(skb, 2 + ie_len); 272 *pos++ = WLAN_EID_PERR; 273 *pos++ = ie_len; 274 /* ttl */ 275 *pos++ = ttl; 276 /* number of destinations */ 277 *pos++ = 1; 278 /* Flags field has AE bit only as defined in 279 * sec 8.4.2.117 IEEE802.11-2012 280 */ 281 *pos = 0; 282 pos++; 283 memcpy(pos, target, ETH_ALEN); 284 pos += ETH_ALEN; 285 put_unaligned_le32(target_sn, pos); 286 pos += 4; 287 put_unaligned_le16(target_rcode, pos); 288 289 /* see note in function header */ 290 prepare_frame_for_deferred_tx(sdata, skb); 291 ifmsh->next_perr = TU_TO_EXP_TIME( 292 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval); 293 ieee80211_add_pending_skb(local, skb); 294 return 0; 295 } 296 297 void ieee80211s_update_metric(struct ieee80211_local *local, 298 struct sta_info *sta, 299 struct ieee80211_tx_status *st) 300 { 301 struct ieee80211_tx_info *txinfo = st->info; 302 int failed; 303 struct rate_info rinfo; 304 305 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 306 307 /* moving average, scaled to 100. 308 * feed failure as 100 and success as 0 309 */ 310 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); 311 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 312 LINK_FAIL_THRESH) 313 mesh_plink_broken(sta); 314 315 /* use rate info set by the driver directly if present */ 316 if (st->n_rates) 317 rinfo = sta->deflink.tx_stats.last_rate_info; 318 else 319 sta_set_rate_info_tx(sta, &sta->deflink.tx_stats.last_rate, &rinfo); 320 321 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg, 322 cfg80211_calculate_bitrate(&rinfo)); 323 } 324 325 u32 airtime_link_metric_get(struct ieee80211_local *local, 326 struct sta_info *sta) 327 { 328 /* This should be adjusted for each device */ 329 int device_constant = 1 << ARITH_SHIFT; 330 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 331 int s_unit = 1 << ARITH_SHIFT; 332 int rate, err; 333 u32 tx_time, estimated_retx; 334 u64 result; 335 unsigned long fail_avg = 336 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 337 338 if (sta->mesh->plink_state != NL80211_PLINK_ESTAB) 339 return MAX_METRIC; 340 341 /* Try to get rate based on HW/SW RC algorithm. 342 * Rate is returned in units of Kbps, correct this 343 * to comply with airtime calculation units 344 * Round up in case we get rate < 100Kbps 345 */ 346 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 347 348 if (rate) { 349 err = 0; 350 } else { 351 if (fail_avg > LINK_FAIL_THRESH) 352 return MAX_METRIC; 353 354 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg); 355 if (WARN_ON(!rate)) 356 return MAX_METRIC; 357 358 err = (fail_avg << ARITH_SHIFT) / 100; 359 } 360 361 /* bitrate is in units of 100 Kbps, while we need rate in units of 362 * 1Mbps. This will be corrected on tx_time computation. 363 */ 364 tx_time = (device_constant + 10 * test_frame_len / rate); 365 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 366 result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT); 367 return (u32)result; 368 } 369 370 /* Check that the first metric is at least 10% better than the second one */ 371 static bool is_metric_better(u32 x, u32 y) 372 { 373 return (x < y) && (x < (y - x / 10)); 374 } 375 376 /** 377 * hwmp_route_info_get - Update routing info to originator and transmitter 378 * 379 * @sdata: local mesh subif 380 * @mgmt: mesh management frame 381 * @hwmp_ie: hwmp information element (PREP or PREQ) 382 * @action: type of hwmp ie 383 * 384 * This function updates the path routing information to the originator and the 385 * transmitter of a HWMP PREQ or PREP frame. 386 * 387 * Returns: metric to frame originator or 0 if the frame should not be further 388 * processed 389 * 390 * Notes: this function is the only place (besides user-provided info) where 391 * path routing information is updated. 392 */ 393 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 394 struct ieee80211_mgmt *mgmt, 395 const u8 *hwmp_ie, enum mpath_frame_type action) 396 { 397 struct ieee80211_local *local = sdata->local; 398 struct mesh_path *mpath; 399 struct sta_info *sta; 400 bool fresh_info; 401 const u8 *orig_addr, *ta; 402 u32 orig_sn, orig_metric; 403 unsigned long orig_lifetime, exp_time; 404 u32 last_hop_metric, new_metric; 405 bool flush_mpath = false; 406 bool process = true; 407 u8 hopcount; 408 409 rcu_read_lock(); 410 sta = sta_info_get(sdata, mgmt->sa); 411 if (!sta) { 412 rcu_read_unlock(); 413 return 0; 414 } 415 416 last_hop_metric = airtime_link_metric_get(local, sta); 417 /* Update and check originator routing info */ 418 fresh_info = true; 419 420 switch (action) { 421 case MPATH_PREQ: 422 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 423 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 424 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 425 orig_metric = PREQ_IE_METRIC(hwmp_ie); 426 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1; 427 break; 428 case MPATH_PREP: 429 /* Originator here refers to the MP that was the target in the 430 * Path Request. We divert from the nomenclature in the draft 431 * so that we can easily use a single function to gather path 432 * information from both PREQ and PREP frames. 433 */ 434 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 435 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 436 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 437 orig_metric = PREP_IE_METRIC(hwmp_ie); 438 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1; 439 break; 440 default: 441 rcu_read_unlock(); 442 return 0; 443 } 444 new_metric = orig_metric + last_hop_metric; 445 if (new_metric < orig_metric) 446 new_metric = MAX_METRIC; 447 exp_time = TU_TO_EXP_TIME(orig_lifetime); 448 449 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 450 /* This MP is the originator, we are not interested in this 451 * frame, except for updating transmitter's path info. 452 */ 453 process = false; 454 fresh_info = false; 455 } else { 456 mpath = mesh_path_lookup(sdata, orig_addr); 457 if (mpath) { 458 spin_lock_bh(&mpath->state_lock); 459 if (mpath->flags & MESH_PATH_FIXED) 460 fresh_info = false; 461 else if ((mpath->flags & MESH_PATH_ACTIVE) && 462 (mpath->flags & MESH_PATH_SN_VALID)) { 463 if (SN_GT(mpath->sn, orig_sn) || 464 (mpath->sn == orig_sn && 465 (rcu_access_pointer(mpath->next_hop) != 466 sta ? 467 !is_metric_better(new_metric, mpath->metric) : 468 new_metric >= mpath->metric))) { 469 process = false; 470 fresh_info = false; 471 } 472 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 473 bool have_sn, newer_sn, bounced; 474 475 have_sn = mpath->flags & MESH_PATH_SN_VALID; 476 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 477 bounced = have_sn && 478 (SN_DELTA(orig_sn, mpath->sn) > 479 MAX_SANE_SN_DELTA); 480 481 if (!have_sn || newer_sn) { 482 /* if SN is newer than what we had 483 * then we can take it */; 484 } else if (bounced) { 485 /* if SN is way different than what 486 * we had then assume the other side 487 * rebooted or restarted */; 488 } else { 489 process = false; 490 fresh_info = false; 491 } 492 } 493 } else { 494 mpath = mesh_path_add(sdata, orig_addr); 495 if (IS_ERR(mpath)) { 496 rcu_read_unlock(); 497 return 0; 498 } 499 spin_lock_bh(&mpath->state_lock); 500 } 501 502 if (fresh_info) { 503 if (rcu_access_pointer(mpath->next_hop) != sta) { 504 mpath->path_change_count++; 505 flush_mpath = true; 506 } 507 mesh_path_assign_nexthop(mpath, sta); 508 mpath->flags |= MESH_PATH_SN_VALID; 509 mpath->metric = new_metric; 510 mpath->sn = orig_sn; 511 mpath->exp_time = time_after(mpath->exp_time, exp_time) 512 ? mpath->exp_time : exp_time; 513 mpath->hop_count = hopcount; 514 mesh_path_activate(mpath); 515 spin_unlock_bh(&mpath->state_lock); 516 if (flush_mpath) 517 mesh_fast_tx_flush_mpath(mpath); 518 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 519 /* init it at a low value - 0 start is tricky */ 520 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 521 mesh_path_tx_pending(mpath); 522 /* draft says preq_id should be saved to, but there does 523 * not seem to be any use for it, skipping by now 524 */ 525 } else 526 spin_unlock_bh(&mpath->state_lock); 527 } 528 529 /* Update and check transmitter routing info */ 530 ta = mgmt->sa; 531 if (ether_addr_equal(orig_addr, ta)) 532 fresh_info = false; 533 else { 534 fresh_info = true; 535 536 mpath = mesh_path_lookup(sdata, ta); 537 if (mpath) { 538 spin_lock_bh(&mpath->state_lock); 539 if ((mpath->flags & MESH_PATH_FIXED) || 540 ((mpath->flags & MESH_PATH_ACTIVE) && 541 ((rcu_access_pointer(mpath->next_hop) != sta ? 542 !is_metric_better(last_hop_metric, mpath->metric) : 543 last_hop_metric > mpath->metric)))) 544 fresh_info = false; 545 } else { 546 mpath = mesh_path_add(sdata, ta); 547 if (IS_ERR(mpath)) { 548 rcu_read_unlock(); 549 return 0; 550 } 551 spin_lock_bh(&mpath->state_lock); 552 } 553 554 if (fresh_info) { 555 if (rcu_access_pointer(mpath->next_hop) != sta) { 556 mpath->path_change_count++; 557 flush_mpath = true; 558 } 559 mesh_path_assign_nexthop(mpath, sta); 560 mpath->metric = last_hop_metric; 561 mpath->exp_time = time_after(mpath->exp_time, exp_time) 562 ? mpath->exp_time : exp_time; 563 mpath->hop_count = 1; 564 mesh_path_activate(mpath); 565 spin_unlock_bh(&mpath->state_lock); 566 if (flush_mpath) 567 mesh_fast_tx_flush_mpath(mpath); 568 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 569 /* init it at a low value - 0 start is tricky */ 570 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 571 mesh_path_tx_pending(mpath); 572 } else 573 spin_unlock_bh(&mpath->state_lock); 574 } 575 576 rcu_read_unlock(); 577 578 return process ? new_metric : 0; 579 } 580 581 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 582 struct ieee80211_mgmt *mgmt, 583 const u8 *preq_elem, u32 orig_metric) 584 { 585 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 586 struct mesh_path *mpath = NULL; 587 const u8 *target_addr, *orig_addr; 588 const u8 *da; 589 u8 target_flags, ttl, flags; 590 u32 orig_sn, target_sn, lifetime, target_metric = 0; 591 bool reply = false; 592 bool forward = true; 593 bool root_is_gate; 594 595 /* Update target SN, if present */ 596 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 597 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 598 target_sn = PREQ_IE_TARGET_SN(preq_elem); 599 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 600 target_flags = PREQ_IE_TARGET_F(preq_elem); 601 /* Proactive PREQ gate announcements */ 602 flags = PREQ_IE_FLAGS(preq_elem); 603 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 604 605 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 606 607 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 608 mhwmp_dbg(sdata, "PREQ is for us\n"); 609 forward = false; 610 reply = true; 611 target_metric = 0; 612 613 if (SN_GT(target_sn, ifmsh->sn)) 614 ifmsh->sn = target_sn; 615 616 if (time_after(jiffies, ifmsh->last_sn_update + 617 net_traversal_jiffies(sdata)) || 618 time_before(jiffies, ifmsh->last_sn_update)) { 619 ++ifmsh->sn; 620 ifmsh->last_sn_update = jiffies; 621 } 622 target_sn = ifmsh->sn; 623 } else if (is_broadcast_ether_addr(target_addr) && 624 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 625 rcu_read_lock(); 626 mpath = mesh_path_lookup(sdata, orig_addr); 627 if (mpath) { 628 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 629 reply = true; 630 target_addr = sdata->vif.addr; 631 target_sn = ++ifmsh->sn; 632 target_metric = 0; 633 ifmsh->last_sn_update = jiffies; 634 } 635 if (root_is_gate) 636 mesh_path_add_gate(mpath); 637 } 638 rcu_read_unlock(); 639 } else { 640 rcu_read_lock(); 641 mpath = mesh_path_lookup(sdata, target_addr); 642 if (mpath) { 643 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 644 SN_LT(mpath->sn, target_sn)) { 645 mpath->sn = target_sn; 646 mpath->flags |= MESH_PATH_SN_VALID; 647 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 648 (mpath->flags & MESH_PATH_ACTIVE)) { 649 reply = true; 650 target_metric = mpath->metric; 651 target_sn = mpath->sn; 652 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 653 target_flags |= IEEE80211_PREQ_TO_FLAG; 654 } 655 } 656 rcu_read_unlock(); 657 } 658 659 if (reply) { 660 lifetime = PREQ_IE_LIFETIME(preq_elem); 661 ttl = ifmsh->mshcfg.element_ttl; 662 if (ttl != 0) { 663 mhwmp_dbg(sdata, "replying to the PREQ\n"); 664 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 665 orig_sn, 0, target_addr, 666 target_sn, mgmt->sa, 0, ttl, 667 lifetime, target_metric, 0, 668 sdata); 669 } else { 670 ifmsh->mshstats.dropped_frames_ttl++; 671 } 672 } 673 674 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 675 u32 preq_id; 676 u8 hopcount; 677 678 ttl = PREQ_IE_TTL(preq_elem); 679 lifetime = PREQ_IE_LIFETIME(preq_elem); 680 if (ttl <= 1) { 681 ifmsh->mshstats.dropped_frames_ttl++; 682 return; 683 } 684 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 685 --ttl; 686 preq_id = PREQ_IE_PREQ_ID(preq_elem); 687 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 688 da = (mpath && mpath->is_root) ? 689 mpath->rann_snd_addr : broadcast_addr; 690 691 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 692 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 693 target_sn = PREQ_IE_TARGET_SN(preq_elem); 694 } 695 696 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 697 orig_sn, target_flags, target_addr, 698 target_sn, da, hopcount, ttl, lifetime, 699 orig_metric, preq_id, sdata); 700 if (!is_multicast_ether_addr(da)) 701 ifmsh->mshstats.fwded_unicast++; 702 else 703 ifmsh->mshstats.fwded_mcast++; 704 ifmsh->mshstats.fwded_frames++; 705 } 706 } 707 708 709 static inline struct sta_info * 710 next_hop_deref_protected(struct mesh_path *mpath) 711 { 712 return rcu_dereference_protected(mpath->next_hop, 713 lockdep_is_held(&mpath->state_lock)); 714 } 715 716 717 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 718 struct ieee80211_mgmt *mgmt, 719 const u8 *prep_elem, u32 metric) 720 { 721 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 722 struct mesh_path *mpath; 723 const u8 *target_addr, *orig_addr; 724 u8 ttl, hopcount, flags; 725 u8 next_hop[ETH_ALEN]; 726 u32 target_sn, orig_sn, lifetime; 727 728 mhwmp_dbg(sdata, "received PREP from %pM\n", 729 PREP_IE_TARGET_ADDR(prep_elem)); 730 731 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 732 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 733 /* destination, no forwarding required */ 734 return; 735 736 if (!ifmsh->mshcfg.dot11MeshForwarding) 737 return; 738 739 ttl = PREP_IE_TTL(prep_elem); 740 if (ttl <= 1) { 741 sdata->u.mesh.mshstats.dropped_frames_ttl++; 742 return; 743 } 744 745 rcu_read_lock(); 746 mpath = mesh_path_lookup(sdata, orig_addr); 747 if (mpath) 748 spin_lock_bh(&mpath->state_lock); 749 else 750 goto fail; 751 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 752 spin_unlock_bh(&mpath->state_lock); 753 goto fail; 754 } 755 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 756 spin_unlock_bh(&mpath->state_lock); 757 --ttl; 758 flags = PREP_IE_FLAGS(prep_elem); 759 lifetime = PREP_IE_LIFETIME(prep_elem); 760 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 761 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 762 target_sn = PREP_IE_TARGET_SN(prep_elem); 763 orig_sn = PREP_IE_ORIG_SN(prep_elem); 764 765 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 766 target_addr, target_sn, next_hop, hopcount, 767 ttl, lifetime, metric, 0, sdata); 768 rcu_read_unlock(); 769 770 sdata->u.mesh.mshstats.fwded_unicast++; 771 sdata->u.mesh.mshstats.fwded_frames++; 772 return; 773 774 fail: 775 rcu_read_unlock(); 776 sdata->u.mesh.mshstats.dropped_frames_no_route++; 777 } 778 779 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 780 struct ieee80211_mgmt *mgmt, 781 const u8 *perr_elem) 782 { 783 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 784 struct mesh_path *mpath; 785 u8 ttl; 786 const u8 *ta, *target_addr; 787 u32 target_sn; 788 u16 target_rcode; 789 790 ta = mgmt->sa; 791 ttl = PERR_IE_TTL(perr_elem); 792 if (ttl <= 1) { 793 ifmsh->mshstats.dropped_frames_ttl++; 794 return; 795 } 796 ttl--; 797 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 798 target_sn = PERR_IE_TARGET_SN(perr_elem); 799 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 800 801 rcu_read_lock(); 802 mpath = mesh_path_lookup(sdata, target_addr); 803 if (mpath) { 804 struct sta_info *sta; 805 806 spin_lock_bh(&mpath->state_lock); 807 sta = next_hop_deref_protected(mpath); 808 if (mpath->flags & MESH_PATH_ACTIVE && 809 ether_addr_equal(ta, sta->sta.addr) && 810 !(mpath->flags & MESH_PATH_FIXED) && 811 (!(mpath->flags & MESH_PATH_SN_VALID) || 812 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 813 mpath->flags &= ~MESH_PATH_ACTIVE; 814 if (target_sn != 0) 815 mpath->sn = target_sn; 816 else 817 mpath->sn += 1; 818 spin_unlock_bh(&mpath->state_lock); 819 if (!ifmsh->mshcfg.dot11MeshForwarding) 820 goto endperr; 821 mesh_path_error_tx(sdata, ttl, target_addr, 822 target_sn, target_rcode, 823 broadcast_addr); 824 } else 825 spin_unlock_bh(&mpath->state_lock); 826 } 827 endperr: 828 rcu_read_unlock(); 829 } 830 831 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 832 struct ieee80211_mgmt *mgmt, 833 const struct ieee80211_rann_ie *rann) 834 { 835 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 836 struct ieee80211_local *local = sdata->local; 837 struct sta_info *sta; 838 struct mesh_path *mpath; 839 u8 ttl, flags, hopcount; 840 const u8 *orig_addr; 841 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; 842 bool root_is_gate; 843 844 ttl = rann->rann_ttl; 845 flags = rann->rann_flags; 846 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 847 orig_addr = rann->rann_addr; 848 orig_sn = le32_to_cpu(rann->rann_seq); 849 interval = le32_to_cpu(rann->rann_interval); 850 hopcount = rann->rann_hopcount; 851 hopcount++; 852 orig_metric = le32_to_cpu(rann->rann_metric); 853 854 /* Ignore our own RANNs */ 855 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 856 return; 857 858 mhwmp_dbg(sdata, 859 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 860 orig_addr, mgmt->sa, root_is_gate); 861 862 rcu_read_lock(); 863 sta = sta_info_get(sdata, mgmt->sa); 864 if (!sta) { 865 rcu_read_unlock(); 866 return; 867 } 868 869 last_hop_metric = airtime_link_metric_get(local, sta); 870 new_metric = orig_metric + last_hop_metric; 871 if (new_metric < orig_metric) 872 new_metric = MAX_METRIC; 873 874 mpath = mesh_path_lookup(sdata, orig_addr); 875 if (!mpath) { 876 mpath = mesh_path_add(sdata, orig_addr); 877 if (IS_ERR(mpath)) { 878 rcu_read_unlock(); 879 sdata->u.mesh.mshstats.dropped_frames_no_route++; 880 return; 881 } 882 } 883 884 if (!(SN_LT(mpath->sn, orig_sn)) && 885 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { 886 rcu_read_unlock(); 887 return; 888 } 889 890 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 891 (time_after(jiffies, mpath->last_preq_to_root + 892 root_path_confirmation_jiffies(sdata)) || 893 time_before(jiffies, mpath->last_preq_to_root))) && 894 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 895 mhwmp_dbg(sdata, 896 "time to refresh root mpath %pM\n", 897 orig_addr); 898 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 899 mpath->last_preq_to_root = jiffies; 900 } 901 902 mpath->sn = orig_sn; 903 mpath->rann_metric = new_metric; 904 mpath->is_root = true; 905 /* Recording RANNs sender address to send individually 906 * addressed PREQs destined for root mesh STA */ 907 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 908 909 if (root_is_gate) 910 mesh_path_add_gate(mpath); 911 912 if (ttl <= 1) { 913 ifmsh->mshstats.dropped_frames_ttl++; 914 rcu_read_unlock(); 915 return; 916 } 917 ttl--; 918 919 if (ifmsh->mshcfg.dot11MeshForwarding) { 920 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 921 orig_sn, 0, NULL, 0, broadcast_addr, 922 hopcount, ttl, interval, 923 new_metric, 0, sdata); 924 } 925 926 rcu_read_unlock(); 927 } 928 929 930 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 931 struct ieee80211_mgmt *mgmt, size_t len) 932 { 933 struct ieee802_11_elems *elems; 934 size_t baselen; 935 u32 path_metric; 936 struct sta_info *sta; 937 938 /* need action_code */ 939 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 940 return; 941 942 rcu_read_lock(); 943 sta = sta_info_get(sdata, mgmt->sa); 944 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 945 rcu_read_unlock(); 946 return; 947 } 948 rcu_read_unlock(); 949 950 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 951 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 952 len - baselen, false, NULL); 953 if (!elems) 954 return; 955 956 if (elems->preq) { 957 if (elems->preq_len != 37) 958 /* Right now we support just 1 destination and no AE */ 959 goto free; 960 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq, 961 MPATH_PREQ); 962 if (path_metric) 963 hwmp_preq_frame_process(sdata, mgmt, elems->preq, 964 path_metric); 965 } 966 if (elems->prep) { 967 if (elems->prep_len != 31) 968 /* Right now we support no AE */ 969 goto free; 970 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep, 971 MPATH_PREP); 972 if (path_metric) 973 hwmp_prep_frame_process(sdata, mgmt, elems->prep, 974 path_metric); 975 } 976 if (elems->perr) { 977 if (elems->perr_len != 15) 978 /* Right now we support only one destination per PERR */ 979 goto free; 980 hwmp_perr_frame_process(sdata, mgmt, elems->perr); 981 } 982 if (elems->rann) 983 hwmp_rann_frame_process(sdata, mgmt, elems->rann); 984 free: 985 kfree(elems); 986 } 987 988 /** 989 * mesh_queue_preq - queue a PREQ to a given destination 990 * 991 * @mpath: mesh path to discover 992 * @flags: special attributes of the PREQ to be sent 993 * 994 * Locking: the function must be called from within a rcu read lock block. 995 * 996 */ 997 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 998 { 999 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1000 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1001 struct mesh_preq_queue *preq_node; 1002 1003 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 1004 if (!preq_node) { 1005 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 1006 return; 1007 } 1008 1009 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1010 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 1011 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1012 kfree(preq_node); 1013 if (printk_ratelimit()) 1014 mhwmp_dbg(sdata, "PREQ node queue full\n"); 1015 return; 1016 } 1017 1018 spin_lock(&mpath->state_lock); 1019 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 1020 spin_unlock(&mpath->state_lock); 1021 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1022 kfree(preq_node); 1023 return; 1024 } 1025 1026 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 1027 preq_node->flags = flags; 1028 1029 mpath->flags |= MESH_PATH_REQ_QUEUED; 1030 spin_unlock(&mpath->state_lock); 1031 1032 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 1033 ++ifmsh->preq_queue_len; 1034 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1035 1036 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 1037 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work); 1038 1039 else if (time_before(jiffies, ifmsh->last_preq)) { 1040 /* avoid long wait if did not send preqs for a long time 1041 * and jiffies wrapped around 1042 */ 1043 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 1044 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work); 1045 } else 1046 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 1047 min_preq_int_jiff(sdata)); 1048 } 1049 1050 /** 1051 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1052 * 1053 * @sdata: local mesh subif 1054 */ 1055 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1056 { 1057 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1058 struct mesh_preq_queue *preq_node; 1059 struct mesh_path *mpath; 1060 u8 ttl, target_flags = 0; 1061 const u8 *da; 1062 u32 lifetime; 1063 1064 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1065 if (!ifmsh->preq_queue_len || 1066 time_before(jiffies, ifmsh->last_preq + 1067 min_preq_int_jiff(sdata))) { 1068 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1069 return; 1070 } 1071 1072 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1073 struct mesh_preq_queue, list); 1074 list_del(&preq_node->list); 1075 --ifmsh->preq_queue_len; 1076 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1077 1078 rcu_read_lock(); 1079 mpath = mesh_path_lookup(sdata, preq_node->dst); 1080 if (!mpath) 1081 goto enddiscovery; 1082 1083 spin_lock_bh(&mpath->state_lock); 1084 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1085 spin_unlock_bh(&mpath->state_lock); 1086 goto enddiscovery; 1087 } 1088 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1089 if (preq_node->flags & PREQ_Q_F_START) { 1090 if (mpath->flags & MESH_PATH_RESOLVING) { 1091 spin_unlock_bh(&mpath->state_lock); 1092 goto enddiscovery; 1093 } else { 1094 mpath->flags &= ~MESH_PATH_RESOLVED; 1095 mpath->flags |= MESH_PATH_RESOLVING; 1096 mpath->discovery_retries = 0; 1097 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1098 } 1099 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1100 mpath->flags & MESH_PATH_RESOLVED) { 1101 mpath->flags &= ~MESH_PATH_RESOLVING; 1102 spin_unlock_bh(&mpath->state_lock); 1103 goto enddiscovery; 1104 } 1105 1106 ifmsh->last_preq = jiffies; 1107 1108 if (time_after(jiffies, ifmsh->last_sn_update + 1109 net_traversal_jiffies(sdata)) || 1110 time_before(jiffies, ifmsh->last_sn_update)) { 1111 ++ifmsh->sn; 1112 sdata->u.mesh.last_sn_update = jiffies; 1113 } 1114 lifetime = default_lifetime(sdata); 1115 ttl = sdata->u.mesh.mshcfg.element_ttl; 1116 if (ttl == 0) { 1117 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1118 spin_unlock_bh(&mpath->state_lock); 1119 goto enddiscovery; 1120 } 1121 1122 if (preq_node->flags & PREQ_Q_F_REFRESH) 1123 target_flags |= IEEE80211_PREQ_TO_FLAG; 1124 else 1125 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1126 1127 spin_unlock_bh(&mpath->state_lock); 1128 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1129 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1130 target_flags, mpath->dst, mpath->sn, da, 0, 1131 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1132 1133 spin_lock_bh(&mpath->state_lock); 1134 if (!(mpath->flags & MESH_PATH_DELETED)) 1135 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1136 spin_unlock_bh(&mpath->state_lock); 1137 1138 enddiscovery: 1139 rcu_read_unlock(); 1140 kfree(preq_node); 1141 } 1142 1143 /** 1144 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1145 * 1146 * @sdata: network subif the frame will be sent through 1147 * @skb: 802.11 frame to be sent 1148 * 1149 * Lookup next hop for given skb and start path discovery if no 1150 * forwarding information is found. 1151 * 1152 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1153 * skb is freed here if no mpath could be allocated. 1154 */ 1155 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1156 struct sk_buff *skb) 1157 { 1158 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1159 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1160 struct mesh_path *mpath; 1161 struct sk_buff *skb_to_free = NULL; 1162 u8 *target_addr = hdr->addr3; 1163 1164 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1165 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1166 return 0; 1167 1168 /* Allow injected packets to bypass mesh routing */ 1169 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP) 1170 return 0; 1171 1172 if (!mesh_nexthop_lookup(sdata, skb)) 1173 return 0; 1174 1175 /* no nexthop found, start resolving */ 1176 mpath = mesh_path_lookup(sdata, target_addr); 1177 if (!mpath) { 1178 mpath = mesh_path_add(sdata, target_addr); 1179 if (IS_ERR(mpath)) { 1180 mesh_path_discard_frame(sdata, skb); 1181 return PTR_ERR(mpath); 1182 } 1183 } 1184 1185 if (!(mpath->flags & MESH_PATH_RESOLVING) && 1186 mesh_path_sel_is_hwmp(sdata)) 1187 mesh_queue_preq(mpath, PREQ_Q_F_START); 1188 1189 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1190 skb_to_free = skb_dequeue(&mpath->frame_queue); 1191 1192 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING; 1193 ieee80211_set_qos_hdr(sdata, skb); 1194 skb_queue_tail(&mpath->frame_queue, skb); 1195 if (skb_to_free) 1196 mesh_path_discard_frame(sdata, skb_to_free); 1197 1198 return -ENOENT; 1199 } 1200 1201 /** 1202 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery 1203 * @skb: 802.11 frame to be sent 1204 * @sdata: network subif the frame will be sent through 1205 * 1206 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor. 1207 * And if so, set the RA (addr1) to it to transmit to this node directly, 1208 * avoiding PREQ/PREP path discovery. 1209 * 1210 * Returns: 0 if the next hop was found and -ENOENT otherwise. 1211 */ 1212 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata, 1213 struct sk_buff *skb) 1214 { 1215 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 1216 struct sta_info *sta; 1217 1218 if (is_multicast_ether_addr(hdr->addr1)) 1219 return -ENOENT; 1220 1221 rcu_read_lock(); 1222 sta = sta_info_get(sdata, hdr->addr3); 1223 1224 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 1225 rcu_read_unlock(); 1226 return -ENOENT; 1227 } 1228 rcu_read_unlock(); 1229 1230 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN); 1231 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1232 return 0; 1233 } 1234 1235 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata, 1236 struct mesh_path *mpath, const u8 *addr) 1237 { 1238 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED | 1239 MESH_PATH_RESOLVING)) 1240 return; 1241 1242 if (time_after(jiffies, 1243 mpath->exp_time - 1244 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1245 (!addr || ether_addr_equal(sdata->vif.addr, addr))) 1246 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1247 } 1248 1249 /** 1250 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1251 * this function is considered "using" the associated mpath, so preempt a path 1252 * refresh if this mpath expires soon. 1253 * 1254 * @sdata: network subif the frame will be sent through 1255 * @skb: 802.11 frame to be sent 1256 * 1257 * Returns: 0 if the next hop was found. Nonzero otherwise. 1258 */ 1259 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1260 struct sk_buff *skb) 1261 { 1262 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1263 struct mesh_path *mpath; 1264 struct sta_info *next_hop; 1265 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1266 u8 *target_addr = hdr->addr3; 1267 1268 if (ifmsh->mshcfg.dot11MeshNolearn && 1269 !mesh_nexthop_lookup_nolearn(sdata, skb)) 1270 return 0; 1271 1272 mpath = mesh_path_lookup(sdata, target_addr); 1273 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1274 return -ENOENT; 1275 1276 mesh_path_refresh(sdata, mpath, hdr->addr4); 1277 1278 next_hop = rcu_dereference(mpath->next_hop); 1279 if (next_hop) { 1280 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1281 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1282 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1283 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT)) 1284 mesh_fast_tx_cache(sdata, skb, mpath); 1285 return 0; 1286 } 1287 1288 return -ENOENT; 1289 } 1290 1291 void mesh_path_timer(struct timer_list *t) 1292 { 1293 struct mesh_path *mpath = from_timer(mpath, t, timer); 1294 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1295 int ret; 1296 1297 if (sdata->local->quiescing) 1298 return; 1299 1300 spin_lock_bh(&mpath->state_lock); 1301 if (mpath->flags & MESH_PATH_RESOLVED || 1302 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1303 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1304 spin_unlock_bh(&mpath->state_lock); 1305 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1306 ++mpath->discovery_retries; 1307 mpath->discovery_timeout *= 2; 1308 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1309 spin_unlock_bh(&mpath->state_lock); 1310 mesh_queue_preq(mpath, 0); 1311 } else { 1312 mpath->flags &= ~(MESH_PATH_RESOLVING | 1313 MESH_PATH_RESOLVED | 1314 MESH_PATH_REQ_QUEUED); 1315 mpath->exp_time = jiffies; 1316 spin_unlock_bh(&mpath->state_lock); 1317 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1318 ret = mesh_path_send_to_gates(mpath); 1319 if (ret) 1320 mhwmp_dbg(sdata, "no gate was reachable\n"); 1321 } else 1322 mesh_path_flush_pending(mpath); 1323 } 1324 } 1325 1326 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1327 { 1328 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1329 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1330 u8 flags, target_flags = 0; 1331 1332 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1333 ? RANN_FLAG_IS_GATE : 0; 1334 1335 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1336 case IEEE80211_PROACTIVE_RANN: 1337 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1338 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1339 0, ifmsh->mshcfg.element_ttl, 1340 interval, 0, 0, sdata); 1341 break; 1342 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1343 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1344 fallthrough; 1345 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1346 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1347 target_flags |= IEEE80211_PREQ_TO_FLAG | 1348 IEEE80211_PREQ_USN_FLAG; 1349 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1350 ++ifmsh->sn, target_flags, 1351 (u8 *) broadcast_addr, 0, broadcast_addr, 1352 0, ifmsh->mshcfg.element_ttl, interval, 1353 0, ifmsh->preq_id++, sdata); 1354 break; 1355 default: 1356 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1357 return; 1358 } 1359 } 1360