1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021-2022 Intel Corporation 5 * Author: Luis Carlos Cobo <luisca@cozybit.com> 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/etherdevice.h> 10 #include <asm/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 -ENOTSUPP; 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 * @ttl: allowed remaining hops 224 * @target: broken destination 225 * @target_sn: SN of the broken destination 226 * @target_rcode: reason code for this PERR 227 * @ra: node this frame is addressed to 228 * @sdata: local mesh subif 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 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata, 235 u8 ttl, const u8 *target, u32 target_sn, 236 u16 target_rcode, const u8 *ra) 237 { 238 struct ieee80211_local *local = sdata->local; 239 struct sk_buff *skb; 240 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 241 struct ieee80211_mgmt *mgmt; 242 u8 *pos, ie_len; 243 int hdr_len = offsetofend(struct ieee80211_mgmt, 244 u.action.u.mesh_action); 245 246 if (time_before(jiffies, ifmsh->next_perr)) 247 return -EAGAIN; 248 249 skb = dev_alloc_skb(local->tx_headroom + 250 IEEE80211_ENCRYPT_HEADROOM + 251 IEEE80211_ENCRYPT_TAILROOM + 252 hdr_len + 253 2 + 15 /* PERR IE */); 254 if (!skb) 255 return -1; 256 skb_reserve(skb, local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM); 257 mgmt = skb_put_zero(skb, hdr_len); 258 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 259 IEEE80211_STYPE_ACTION); 260 261 memcpy(mgmt->da, ra, ETH_ALEN); 262 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 263 /* BSSID == SA */ 264 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 265 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 266 mgmt->u.action.u.mesh_action.action_code = 267 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 268 ie_len = 15; 269 pos = skb_put(skb, 2 + ie_len); 270 *pos++ = WLAN_EID_PERR; 271 *pos++ = ie_len; 272 /* ttl */ 273 *pos++ = ttl; 274 /* number of destinations */ 275 *pos++ = 1; 276 /* Flags field has AE bit only as defined in 277 * sec 8.4.2.117 IEEE802.11-2012 278 */ 279 *pos = 0; 280 pos++; 281 memcpy(pos, target, ETH_ALEN); 282 pos += ETH_ALEN; 283 put_unaligned_le32(target_sn, pos); 284 pos += 4; 285 put_unaligned_le16(target_rcode, pos); 286 287 /* see note in function header */ 288 prepare_frame_for_deferred_tx(sdata, skb); 289 ifmsh->next_perr = TU_TO_EXP_TIME( 290 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval); 291 ieee80211_add_pending_skb(local, skb); 292 return 0; 293 } 294 295 void ieee80211s_update_metric(struct ieee80211_local *local, 296 struct sta_info *sta, 297 struct ieee80211_tx_status *st) 298 { 299 struct ieee80211_tx_info *txinfo = st->info; 300 int failed; 301 struct rate_info rinfo; 302 303 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 304 305 /* moving average, scaled to 100. 306 * feed failure as 100 and success as 0 307 */ 308 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); 309 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 310 LINK_FAIL_THRESH) 311 mesh_plink_broken(sta); 312 313 /* use rate info set by the driver directly if present */ 314 if (st->n_rates) 315 rinfo = sta->deflink.tx_stats.last_rate_info; 316 else 317 sta_set_rate_info_tx(sta, &sta->deflink.tx_stats.last_rate, &rinfo); 318 319 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg, 320 cfg80211_calculate_bitrate(&rinfo)); 321 } 322 323 u32 airtime_link_metric_get(struct ieee80211_local *local, 324 struct sta_info *sta) 325 { 326 /* This should be adjusted for each device */ 327 int device_constant = 1 << ARITH_SHIFT; 328 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 329 int s_unit = 1 << ARITH_SHIFT; 330 int rate, err; 331 u32 tx_time, estimated_retx; 332 u64 result; 333 unsigned long fail_avg = 334 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 335 336 if (sta->mesh->plink_state != NL80211_PLINK_ESTAB) 337 return MAX_METRIC; 338 339 /* Try to get rate based on HW/SW RC algorithm. 340 * Rate is returned in units of Kbps, correct this 341 * to comply with airtime calculation units 342 * Round up in case we get rate < 100Kbps 343 */ 344 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 345 346 if (rate) { 347 err = 0; 348 } else { 349 if (fail_avg > LINK_FAIL_THRESH) 350 return MAX_METRIC; 351 352 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg); 353 if (WARN_ON(!rate)) 354 return MAX_METRIC; 355 356 err = (fail_avg << ARITH_SHIFT) / 100; 357 } 358 359 /* bitrate is in units of 100 Kbps, while we need rate in units of 360 * 1Mbps. This will be corrected on tx_time computation. 361 */ 362 tx_time = (device_constant + 10 * test_frame_len / rate); 363 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 364 result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT); 365 return (u32)result; 366 } 367 368 /** 369 * hwmp_route_info_get - Update routing info to originator and transmitter 370 * 371 * @sdata: local mesh subif 372 * @mgmt: mesh management frame 373 * @hwmp_ie: hwmp information element (PREP or PREQ) 374 * @action: type of hwmp ie 375 * 376 * This function updates the path routing information to the originator and the 377 * transmitter of a HWMP PREQ or PREP frame. 378 * 379 * Returns: metric to frame originator or 0 if the frame should not be further 380 * processed 381 * 382 * Notes: this function is the only place (besides user-provided info) where 383 * path routing information is updated. 384 */ 385 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 386 struct ieee80211_mgmt *mgmt, 387 const u8 *hwmp_ie, enum mpath_frame_type action) 388 { 389 struct ieee80211_local *local = sdata->local; 390 struct mesh_path *mpath; 391 struct sta_info *sta; 392 bool fresh_info; 393 const u8 *orig_addr, *ta; 394 u32 orig_sn, orig_metric; 395 unsigned long orig_lifetime, exp_time; 396 u32 last_hop_metric, new_metric; 397 bool flush_mpath = false; 398 bool process = true; 399 u8 hopcount; 400 401 rcu_read_lock(); 402 sta = sta_info_get(sdata, mgmt->sa); 403 if (!sta) { 404 rcu_read_unlock(); 405 return 0; 406 } 407 408 last_hop_metric = airtime_link_metric_get(local, sta); 409 /* Update and check originator routing info */ 410 fresh_info = true; 411 412 switch (action) { 413 case MPATH_PREQ: 414 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 415 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 416 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 417 orig_metric = PREQ_IE_METRIC(hwmp_ie); 418 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1; 419 break; 420 case MPATH_PREP: 421 /* Originator here refers to the MP that was the target in the 422 * Path Request. We divert from the nomenclature in the draft 423 * so that we can easily use a single function to gather path 424 * information from both PREQ and PREP frames. 425 */ 426 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 427 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 428 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 429 orig_metric = PREP_IE_METRIC(hwmp_ie); 430 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1; 431 break; 432 default: 433 rcu_read_unlock(); 434 return 0; 435 } 436 new_metric = orig_metric + last_hop_metric; 437 if (new_metric < orig_metric) 438 new_metric = MAX_METRIC; 439 exp_time = TU_TO_EXP_TIME(orig_lifetime); 440 441 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 442 /* This MP is the originator, we are not interested in this 443 * frame, except for updating transmitter's path info. 444 */ 445 process = false; 446 fresh_info = false; 447 } else { 448 mpath = mesh_path_lookup(sdata, orig_addr); 449 if (mpath) { 450 spin_lock_bh(&mpath->state_lock); 451 if (mpath->flags & MESH_PATH_FIXED) 452 fresh_info = false; 453 else if ((mpath->flags & MESH_PATH_ACTIVE) && 454 (mpath->flags & MESH_PATH_SN_VALID)) { 455 if (SN_GT(mpath->sn, orig_sn) || 456 (mpath->sn == orig_sn && 457 (rcu_access_pointer(mpath->next_hop) != 458 sta ? 459 mult_frac(new_metric, 10, 9) : 460 new_metric) >= mpath->metric)) { 461 process = false; 462 fresh_info = false; 463 } 464 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 465 bool have_sn, newer_sn, bounced; 466 467 have_sn = mpath->flags & MESH_PATH_SN_VALID; 468 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 469 bounced = have_sn && 470 (SN_DELTA(orig_sn, mpath->sn) > 471 MAX_SANE_SN_DELTA); 472 473 if (!have_sn || newer_sn) { 474 /* if SN is newer than what we had 475 * then we can take it */; 476 } else if (bounced) { 477 /* if SN is way different than what 478 * we had then assume the other side 479 * rebooted or restarted */; 480 } else { 481 process = false; 482 fresh_info = false; 483 } 484 } 485 } else { 486 mpath = mesh_path_add(sdata, orig_addr); 487 if (IS_ERR(mpath)) { 488 rcu_read_unlock(); 489 return 0; 490 } 491 spin_lock_bh(&mpath->state_lock); 492 } 493 494 if (fresh_info) { 495 if (rcu_access_pointer(mpath->next_hop) != sta) { 496 mpath->path_change_count++; 497 flush_mpath = true; 498 } 499 mesh_path_assign_nexthop(mpath, sta); 500 mpath->flags |= MESH_PATH_SN_VALID; 501 mpath->metric = new_metric; 502 mpath->sn = orig_sn; 503 mpath->exp_time = time_after(mpath->exp_time, exp_time) 504 ? mpath->exp_time : exp_time; 505 mpath->hop_count = hopcount; 506 mesh_path_activate(mpath); 507 spin_unlock_bh(&mpath->state_lock); 508 if (flush_mpath) 509 mesh_fast_tx_flush_mpath(mpath); 510 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 511 /* init it at a low value - 0 start is tricky */ 512 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 513 mesh_path_tx_pending(mpath); 514 /* draft says preq_id should be saved to, but there does 515 * not seem to be any use for it, skipping by now 516 */ 517 } else 518 spin_unlock_bh(&mpath->state_lock); 519 } 520 521 /* Update and check transmitter routing info */ 522 ta = mgmt->sa; 523 if (ether_addr_equal(orig_addr, ta)) 524 fresh_info = false; 525 else { 526 fresh_info = true; 527 528 mpath = mesh_path_lookup(sdata, ta); 529 if (mpath) { 530 spin_lock_bh(&mpath->state_lock); 531 if ((mpath->flags & MESH_PATH_FIXED) || 532 ((mpath->flags & MESH_PATH_ACTIVE) && 533 ((rcu_access_pointer(mpath->next_hop) != sta ? 534 mult_frac(last_hop_metric, 10, 9) : 535 last_hop_metric) > mpath->metric))) 536 fresh_info = false; 537 } else { 538 mpath = mesh_path_add(sdata, ta); 539 if (IS_ERR(mpath)) { 540 rcu_read_unlock(); 541 return 0; 542 } 543 spin_lock_bh(&mpath->state_lock); 544 } 545 546 if (fresh_info) { 547 if (rcu_access_pointer(mpath->next_hop) != sta) { 548 mpath->path_change_count++; 549 flush_mpath = true; 550 } 551 mesh_path_assign_nexthop(mpath, sta); 552 mpath->metric = last_hop_metric; 553 mpath->exp_time = time_after(mpath->exp_time, exp_time) 554 ? mpath->exp_time : exp_time; 555 mpath->hop_count = 1; 556 mesh_path_activate(mpath); 557 spin_unlock_bh(&mpath->state_lock); 558 if (flush_mpath) 559 mesh_fast_tx_flush_mpath(mpath); 560 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 561 /* init it at a low value - 0 start is tricky */ 562 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 563 mesh_path_tx_pending(mpath); 564 } else 565 spin_unlock_bh(&mpath->state_lock); 566 } 567 568 rcu_read_unlock(); 569 570 return process ? new_metric : 0; 571 } 572 573 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 574 struct ieee80211_mgmt *mgmt, 575 const u8 *preq_elem, u32 orig_metric) 576 { 577 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 578 struct mesh_path *mpath = NULL; 579 const u8 *target_addr, *orig_addr; 580 const u8 *da; 581 u8 target_flags, ttl, flags; 582 u32 orig_sn, target_sn, lifetime, target_metric = 0; 583 bool reply = false; 584 bool forward = true; 585 bool root_is_gate; 586 587 /* Update target SN, if present */ 588 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 589 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 590 target_sn = PREQ_IE_TARGET_SN(preq_elem); 591 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 592 target_flags = PREQ_IE_TARGET_F(preq_elem); 593 /* Proactive PREQ gate announcements */ 594 flags = PREQ_IE_FLAGS(preq_elem); 595 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 596 597 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 598 599 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 600 mhwmp_dbg(sdata, "PREQ is for us\n"); 601 forward = false; 602 reply = true; 603 target_metric = 0; 604 605 if (SN_GT(target_sn, ifmsh->sn)) 606 ifmsh->sn = target_sn; 607 608 if (time_after(jiffies, ifmsh->last_sn_update + 609 net_traversal_jiffies(sdata)) || 610 time_before(jiffies, ifmsh->last_sn_update)) { 611 ++ifmsh->sn; 612 ifmsh->last_sn_update = jiffies; 613 } 614 target_sn = ifmsh->sn; 615 } else if (is_broadcast_ether_addr(target_addr) && 616 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 617 rcu_read_lock(); 618 mpath = mesh_path_lookup(sdata, orig_addr); 619 if (mpath) { 620 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 621 reply = true; 622 target_addr = sdata->vif.addr; 623 target_sn = ++ifmsh->sn; 624 target_metric = 0; 625 ifmsh->last_sn_update = jiffies; 626 } 627 if (root_is_gate) 628 mesh_path_add_gate(mpath); 629 } 630 rcu_read_unlock(); 631 } else { 632 rcu_read_lock(); 633 mpath = mesh_path_lookup(sdata, target_addr); 634 if (mpath) { 635 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 636 SN_LT(mpath->sn, target_sn)) { 637 mpath->sn = target_sn; 638 mpath->flags |= MESH_PATH_SN_VALID; 639 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 640 (mpath->flags & MESH_PATH_ACTIVE)) { 641 reply = true; 642 target_metric = mpath->metric; 643 target_sn = mpath->sn; 644 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 645 target_flags |= IEEE80211_PREQ_TO_FLAG; 646 } 647 } 648 rcu_read_unlock(); 649 } 650 651 if (reply) { 652 lifetime = PREQ_IE_LIFETIME(preq_elem); 653 ttl = ifmsh->mshcfg.element_ttl; 654 if (ttl != 0) { 655 mhwmp_dbg(sdata, "replying to the PREQ\n"); 656 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 657 orig_sn, 0, target_addr, 658 target_sn, mgmt->sa, 0, ttl, 659 lifetime, target_metric, 0, 660 sdata); 661 } else { 662 ifmsh->mshstats.dropped_frames_ttl++; 663 } 664 } 665 666 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 667 u32 preq_id; 668 u8 hopcount; 669 670 ttl = PREQ_IE_TTL(preq_elem); 671 lifetime = PREQ_IE_LIFETIME(preq_elem); 672 if (ttl <= 1) { 673 ifmsh->mshstats.dropped_frames_ttl++; 674 return; 675 } 676 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 677 --ttl; 678 preq_id = PREQ_IE_PREQ_ID(preq_elem); 679 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 680 da = (mpath && mpath->is_root) ? 681 mpath->rann_snd_addr : broadcast_addr; 682 683 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 684 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 685 target_sn = PREQ_IE_TARGET_SN(preq_elem); 686 } 687 688 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 689 orig_sn, target_flags, target_addr, 690 target_sn, da, hopcount, ttl, lifetime, 691 orig_metric, preq_id, sdata); 692 if (!is_multicast_ether_addr(da)) 693 ifmsh->mshstats.fwded_unicast++; 694 else 695 ifmsh->mshstats.fwded_mcast++; 696 ifmsh->mshstats.fwded_frames++; 697 } 698 } 699 700 701 static inline struct sta_info * 702 next_hop_deref_protected(struct mesh_path *mpath) 703 { 704 return rcu_dereference_protected(mpath->next_hop, 705 lockdep_is_held(&mpath->state_lock)); 706 } 707 708 709 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 710 struct ieee80211_mgmt *mgmt, 711 const u8 *prep_elem, u32 metric) 712 { 713 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 714 struct mesh_path *mpath; 715 const u8 *target_addr, *orig_addr; 716 u8 ttl, hopcount, flags; 717 u8 next_hop[ETH_ALEN]; 718 u32 target_sn, orig_sn, lifetime; 719 720 mhwmp_dbg(sdata, "received PREP from %pM\n", 721 PREP_IE_TARGET_ADDR(prep_elem)); 722 723 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 724 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 725 /* destination, no forwarding required */ 726 return; 727 728 if (!ifmsh->mshcfg.dot11MeshForwarding) 729 return; 730 731 ttl = PREP_IE_TTL(prep_elem); 732 if (ttl <= 1) { 733 sdata->u.mesh.mshstats.dropped_frames_ttl++; 734 return; 735 } 736 737 rcu_read_lock(); 738 mpath = mesh_path_lookup(sdata, orig_addr); 739 if (mpath) 740 spin_lock_bh(&mpath->state_lock); 741 else 742 goto fail; 743 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 744 spin_unlock_bh(&mpath->state_lock); 745 goto fail; 746 } 747 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 748 spin_unlock_bh(&mpath->state_lock); 749 --ttl; 750 flags = PREP_IE_FLAGS(prep_elem); 751 lifetime = PREP_IE_LIFETIME(prep_elem); 752 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 753 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 754 target_sn = PREP_IE_TARGET_SN(prep_elem); 755 orig_sn = PREP_IE_ORIG_SN(prep_elem); 756 757 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 758 target_addr, target_sn, next_hop, hopcount, 759 ttl, lifetime, metric, 0, sdata); 760 rcu_read_unlock(); 761 762 sdata->u.mesh.mshstats.fwded_unicast++; 763 sdata->u.mesh.mshstats.fwded_frames++; 764 return; 765 766 fail: 767 rcu_read_unlock(); 768 sdata->u.mesh.mshstats.dropped_frames_no_route++; 769 } 770 771 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 772 struct ieee80211_mgmt *mgmt, 773 const u8 *perr_elem) 774 { 775 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 776 struct mesh_path *mpath; 777 u8 ttl; 778 const u8 *ta, *target_addr; 779 u32 target_sn; 780 u16 target_rcode; 781 782 ta = mgmt->sa; 783 ttl = PERR_IE_TTL(perr_elem); 784 if (ttl <= 1) { 785 ifmsh->mshstats.dropped_frames_ttl++; 786 return; 787 } 788 ttl--; 789 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 790 target_sn = PERR_IE_TARGET_SN(perr_elem); 791 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 792 793 rcu_read_lock(); 794 mpath = mesh_path_lookup(sdata, target_addr); 795 if (mpath) { 796 struct sta_info *sta; 797 798 spin_lock_bh(&mpath->state_lock); 799 sta = next_hop_deref_protected(mpath); 800 if (mpath->flags & MESH_PATH_ACTIVE && 801 ether_addr_equal(ta, sta->sta.addr) && 802 !(mpath->flags & MESH_PATH_FIXED) && 803 (!(mpath->flags & MESH_PATH_SN_VALID) || 804 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 805 mpath->flags &= ~MESH_PATH_ACTIVE; 806 if (target_sn != 0) 807 mpath->sn = target_sn; 808 else 809 mpath->sn += 1; 810 spin_unlock_bh(&mpath->state_lock); 811 if (!ifmsh->mshcfg.dot11MeshForwarding) 812 goto endperr; 813 mesh_path_error_tx(sdata, ttl, target_addr, 814 target_sn, target_rcode, 815 broadcast_addr); 816 } else 817 spin_unlock_bh(&mpath->state_lock); 818 } 819 endperr: 820 rcu_read_unlock(); 821 } 822 823 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 824 struct ieee80211_mgmt *mgmt, 825 const struct ieee80211_rann_ie *rann) 826 { 827 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 828 struct ieee80211_local *local = sdata->local; 829 struct sta_info *sta; 830 struct mesh_path *mpath; 831 u8 ttl, flags, hopcount; 832 const u8 *orig_addr; 833 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; 834 bool root_is_gate; 835 836 ttl = rann->rann_ttl; 837 flags = rann->rann_flags; 838 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 839 orig_addr = rann->rann_addr; 840 orig_sn = le32_to_cpu(rann->rann_seq); 841 interval = le32_to_cpu(rann->rann_interval); 842 hopcount = rann->rann_hopcount; 843 hopcount++; 844 orig_metric = le32_to_cpu(rann->rann_metric); 845 846 /* Ignore our own RANNs */ 847 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 848 return; 849 850 mhwmp_dbg(sdata, 851 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 852 orig_addr, mgmt->sa, root_is_gate); 853 854 rcu_read_lock(); 855 sta = sta_info_get(sdata, mgmt->sa); 856 if (!sta) { 857 rcu_read_unlock(); 858 return; 859 } 860 861 last_hop_metric = airtime_link_metric_get(local, sta); 862 new_metric = orig_metric + last_hop_metric; 863 if (new_metric < orig_metric) 864 new_metric = MAX_METRIC; 865 866 mpath = mesh_path_lookup(sdata, orig_addr); 867 if (!mpath) { 868 mpath = mesh_path_add(sdata, orig_addr); 869 if (IS_ERR(mpath)) { 870 rcu_read_unlock(); 871 sdata->u.mesh.mshstats.dropped_frames_no_route++; 872 return; 873 } 874 } 875 876 if (!(SN_LT(mpath->sn, orig_sn)) && 877 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { 878 rcu_read_unlock(); 879 return; 880 } 881 882 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 883 (time_after(jiffies, mpath->last_preq_to_root + 884 root_path_confirmation_jiffies(sdata)) || 885 time_before(jiffies, mpath->last_preq_to_root))) && 886 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 887 mhwmp_dbg(sdata, 888 "time to refresh root mpath %pM\n", 889 orig_addr); 890 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 891 mpath->last_preq_to_root = jiffies; 892 } 893 894 mpath->sn = orig_sn; 895 mpath->rann_metric = new_metric; 896 mpath->is_root = true; 897 /* Recording RANNs sender address to send individually 898 * addressed PREQs destined for root mesh STA */ 899 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 900 901 if (root_is_gate) 902 mesh_path_add_gate(mpath); 903 904 if (ttl <= 1) { 905 ifmsh->mshstats.dropped_frames_ttl++; 906 rcu_read_unlock(); 907 return; 908 } 909 ttl--; 910 911 if (ifmsh->mshcfg.dot11MeshForwarding) { 912 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 913 orig_sn, 0, NULL, 0, broadcast_addr, 914 hopcount, ttl, interval, 915 new_metric, 0, sdata); 916 } 917 918 rcu_read_unlock(); 919 } 920 921 922 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 923 struct ieee80211_mgmt *mgmt, size_t len) 924 { 925 struct ieee802_11_elems *elems; 926 size_t baselen; 927 u32 path_metric; 928 struct sta_info *sta; 929 930 /* need action_code */ 931 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 932 return; 933 934 rcu_read_lock(); 935 sta = sta_info_get(sdata, mgmt->sa); 936 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 937 rcu_read_unlock(); 938 return; 939 } 940 rcu_read_unlock(); 941 942 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 943 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 944 len - baselen, false, NULL); 945 if (!elems) 946 return; 947 948 if (elems->preq) { 949 if (elems->preq_len != 37) 950 /* Right now we support just 1 destination and no AE */ 951 goto free; 952 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq, 953 MPATH_PREQ); 954 if (path_metric) 955 hwmp_preq_frame_process(sdata, mgmt, elems->preq, 956 path_metric); 957 } 958 if (elems->prep) { 959 if (elems->prep_len != 31) 960 /* Right now we support no AE */ 961 goto free; 962 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep, 963 MPATH_PREP); 964 if (path_metric) 965 hwmp_prep_frame_process(sdata, mgmt, elems->prep, 966 path_metric); 967 } 968 if (elems->perr) { 969 if (elems->perr_len != 15) 970 /* Right now we support only one destination per PERR */ 971 goto free; 972 hwmp_perr_frame_process(sdata, mgmt, elems->perr); 973 } 974 if (elems->rann) 975 hwmp_rann_frame_process(sdata, mgmt, elems->rann); 976 free: 977 kfree(elems); 978 } 979 980 /** 981 * mesh_queue_preq - queue a PREQ to a given destination 982 * 983 * @mpath: mesh path to discover 984 * @flags: special attributes of the PREQ to be sent 985 * 986 * Locking: the function must be called from within a rcu read lock block. 987 * 988 */ 989 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 990 { 991 struct ieee80211_sub_if_data *sdata = mpath->sdata; 992 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 993 struct mesh_preq_queue *preq_node; 994 995 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 996 if (!preq_node) { 997 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 998 return; 999 } 1000 1001 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1002 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 1003 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1004 kfree(preq_node); 1005 if (printk_ratelimit()) 1006 mhwmp_dbg(sdata, "PREQ node queue full\n"); 1007 return; 1008 } 1009 1010 spin_lock(&mpath->state_lock); 1011 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 1012 spin_unlock(&mpath->state_lock); 1013 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1014 kfree(preq_node); 1015 return; 1016 } 1017 1018 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 1019 preq_node->flags = flags; 1020 1021 mpath->flags |= MESH_PATH_REQ_QUEUED; 1022 spin_unlock(&mpath->state_lock); 1023 1024 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 1025 ++ifmsh->preq_queue_len; 1026 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1027 1028 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 1029 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1030 1031 else if (time_before(jiffies, ifmsh->last_preq)) { 1032 /* avoid long wait if did not send preqs for a long time 1033 * and jiffies wrapped around 1034 */ 1035 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 1036 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1037 } else 1038 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 1039 min_preq_int_jiff(sdata)); 1040 } 1041 1042 /** 1043 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1044 * 1045 * @sdata: local mesh subif 1046 */ 1047 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1048 { 1049 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1050 struct mesh_preq_queue *preq_node; 1051 struct mesh_path *mpath; 1052 u8 ttl, target_flags = 0; 1053 const u8 *da; 1054 u32 lifetime; 1055 1056 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1057 if (!ifmsh->preq_queue_len || 1058 time_before(jiffies, ifmsh->last_preq + 1059 min_preq_int_jiff(sdata))) { 1060 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1061 return; 1062 } 1063 1064 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1065 struct mesh_preq_queue, list); 1066 list_del(&preq_node->list); 1067 --ifmsh->preq_queue_len; 1068 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1069 1070 rcu_read_lock(); 1071 mpath = mesh_path_lookup(sdata, preq_node->dst); 1072 if (!mpath) 1073 goto enddiscovery; 1074 1075 spin_lock_bh(&mpath->state_lock); 1076 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1077 spin_unlock_bh(&mpath->state_lock); 1078 goto enddiscovery; 1079 } 1080 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1081 if (preq_node->flags & PREQ_Q_F_START) { 1082 if (mpath->flags & MESH_PATH_RESOLVING) { 1083 spin_unlock_bh(&mpath->state_lock); 1084 goto enddiscovery; 1085 } else { 1086 mpath->flags &= ~MESH_PATH_RESOLVED; 1087 mpath->flags |= MESH_PATH_RESOLVING; 1088 mpath->discovery_retries = 0; 1089 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1090 } 1091 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1092 mpath->flags & MESH_PATH_RESOLVED) { 1093 mpath->flags &= ~MESH_PATH_RESOLVING; 1094 spin_unlock_bh(&mpath->state_lock); 1095 goto enddiscovery; 1096 } 1097 1098 ifmsh->last_preq = jiffies; 1099 1100 if (time_after(jiffies, ifmsh->last_sn_update + 1101 net_traversal_jiffies(sdata)) || 1102 time_before(jiffies, ifmsh->last_sn_update)) { 1103 ++ifmsh->sn; 1104 sdata->u.mesh.last_sn_update = jiffies; 1105 } 1106 lifetime = default_lifetime(sdata); 1107 ttl = sdata->u.mesh.mshcfg.element_ttl; 1108 if (ttl == 0) { 1109 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1110 spin_unlock_bh(&mpath->state_lock); 1111 goto enddiscovery; 1112 } 1113 1114 if (preq_node->flags & PREQ_Q_F_REFRESH) 1115 target_flags |= IEEE80211_PREQ_TO_FLAG; 1116 else 1117 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1118 1119 spin_unlock_bh(&mpath->state_lock); 1120 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1121 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1122 target_flags, mpath->dst, mpath->sn, da, 0, 1123 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1124 1125 spin_lock_bh(&mpath->state_lock); 1126 if (!(mpath->flags & MESH_PATH_DELETED)) 1127 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1128 spin_unlock_bh(&mpath->state_lock); 1129 1130 enddiscovery: 1131 rcu_read_unlock(); 1132 kfree(preq_node); 1133 } 1134 1135 /** 1136 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1137 * 1138 * @skb: 802.11 frame to be sent 1139 * @sdata: network subif the frame will be sent through 1140 * 1141 * Lookup next hop for given skb and start path discovery if no 1142 * forwarding information is found. 1143 * 1144 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1145 * skb is freed here if no mpath could be allocated. 1146 */ 1147 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1148 struct sk_buff *skb) 1149 { 1150 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1151 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1152 struct mesh_path *mpath; 1153 struct sk_buff *skb_to_free = NULL; 1154 u8 *target_addr = hdr->addr3; 1155 1156 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1157 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1158 return 0; 1159 1160 /* Allow injected packets to bypass mesh routing */ 1161 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP) 1162 return 0; 1163 1164 if (!mesh_nexthop_lookup(sdata, skb)) 1165 return 0; 1166 1167 /* no nexthop found, start resolving */ 1168 mpath = mesh_path_lookup(sdata, target_addr); 1169 if (!mpath) { 1170 mpath = mesh_path_add(sdata, target_addr); 1171 if (IS_ERR(mpath)) { 1172 mesh_path_discard_frame(sdata, skb); 1173 return PTR_ERR(mpath); 1174 } 1175 } 1176 1177 if (!(mpath->flags & MESH_PATH_RESOLVING) && 1178 mesh_path_sel_is_hwmp(sdata)) 1179 mesh_queue_preq(mpath, PREQ_Q_F_START); 1180 1181 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1182 skb_to_free = skb_dequeue(&mpath->frame_queue); 1183 1184 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING; 1185 ieee80211_set_qos_hdr(sdata, skb); 1186 skb_queue_tail(&mpath->frame_queue, skb); 1187 if (skb_to_free) 1188 mesh_path_discard_frame(sdata, skb_to_free); 1189 1190 return -ENOENT; 1191 } 1192 1193 /** 1194 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery 1195 * @skb: 802.11 frame to be sent 1196 * @sdata: network subif the frame will be sent through 1197 * 1198 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor. 1199 * And if so, set the RA (addr1) to it to transmit to this node directly, 1200 * avoiding PREQ/PREP path discovery. 1201 * 1202 * Returns: 0 if the next hop was found and -ENOENT otherwise. 1203 */ 1204 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata, 1205 struct sk_buff *skb) 1206 { 1207 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 1208 struct sta_info *sta; 1209 1210 if (is_multicast_ether_addr(hdr->addr1)) 1211 return -ENOENT; 1212 1213 rcu_read_lock(); 1214 sta = sta_info_get(sdata, hdr->addr3); 1215 1216 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 1217 rcu_read_unlock(); 1218 return -ENOENT; 1219 } 1220 rcu_read_unlock(); 1221 1222 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN); 1223 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1224 return 0; 1225 } 1226 1227 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata, 1228 struct mesh_path *mpath, const u8 *addr) 1229 { 1230 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED | 1231 MESH_PATH_RESOLVING)) 1232 return; 1233 1234 if (time_after(jiffies, 1235 mpath->exp_time - 1236 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1237 (!addr || ether_addr_equal(sdata->vif.addr, addr))) 1238 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1239 } 1240 1241 /** 1242 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1243 * this function is considered "using" the associated mpath, so preempt a path 1244 * refresh if this mpath expires soon. 1245 * 1246 * @skb: 802.11 frame to be sent 1247 * @sdata: network subif the frame will be sent through 1248 * 1249 * Returns: 0 if the next hop was found. Nonzero otherwise. 1250 */ 1251 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1252 struct sk_buff *skb) 1253 { 1254 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1255 struct mesh_path *mpath; 1256 struct sta_info *next_hop; 1257 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1258 u8 *target_addr = hdr->addr3; 1259 1260 if (ifmsh->mshcfg.dot11MeshNolearn && 1261 !mesh_nexthop_lookup_nolearn(sdata, skb)) 1262 return 0; 1263 1264 mpath = mesh_path_lookup(sdata, target_addr); 1265 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1266 return -ENOENT; 1267 1268 mesh_path_refresh(sdata, mpath, hdr->addr4); 1269 1270 next_hop = rcu_dereference(mpath->next_hop); 1271 if (next_hop) { 1272 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1273 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1274 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1275 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT)) 1276 mesh_fast_tx_cache(sdata, skb, mpath); 1277 return 0; 1278 } 1279 1280 return -ENOENT; 1281 } 1282 1283 void mesh_path_timer(struct timer_list *t) 1284 { 1285 struct mesh_path *mpath = from_timer(mpath, t, timer); 1286 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1287 int ret; 1288 1289 if (sdata->local->quiescing) 1290 return; 1291 1292 spin_lock_bh(&mpath->state_lock); 1293 if (mpath->flags & MESH_PATH_RESOLVED || 1294 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1295 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1296 spin_unlock_bh(&mpath->state_lock); 1297 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1298 ++mpath->discovery_retries; 1299 mpath->discovery_timeout *= 2; 1300 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1301 spin_unlock_bh(&mpath->state_lock); 1302 mesh_queue_preq(mpath, 0); 1303 } else { 1304 mpath->flags &= ~(MESH_PATH_RESOLVING | 1305 MESH_PATH_RESOLVED | 1306 MESH_PATH_REQ_QUEUED); 1307 mpath->exp_time = jiffies; 1308 spin_unlock_bh(&mpath->state_lock); 1309 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1310 ret = mesh_path_send_to_gates(mpath); 1311 if (ret) 1312 mhwmp_dbg(sdata, "no gate was reachable\n"); 1313 } else 1314 mesh_path_flush_pending(mpath); 1315 } 1316 } 1317 1318 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1319 { 1320 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1321 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1322 u8 flags, target_flags = 0; 1323 1324 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1325 ? RANN_FLAG_IS_GATE : 0; 1326 1327 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1328 case IEEE80211_PROACTIVE_RANN: 1329 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1330 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1331 0, ifmsh->mshcfg.element_ttl, 1332 interval, 0, 0, sdata); 1333 break; 1334 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1335 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1336 fallthrough; 1337 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1338 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1339 target_flags |= IEEE80211_PREQ_TO_FLAG | 1340 IEEE80211_PREQ_USN_FLAG; 1341 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1342 ++ifmsh->sn, target_flags, 1343 (u8 *) broadcast_addr, 0, broadcast_addr, 1344 0, ifmsh->mshcfg.element_ttl, interval, 1345 0, ifmsh->preq_id++, sdata); 1346 break; 1347 default: 1348 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1349 return; 1350 } 1351 } 1352