1 /* 2 * Copyright (c) 2008, 2009 open80211s Ltd. 3 * Author: Luis Carlos Cobo <luisca@cozybit.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 10 #include <linux/slab.h> 11 #include <linux/etherdevice.h> 12 #include <asm/unaligned.h> 13 #include "wme.h" 14 #include "mesh.h" 15 16 #define TEST_FRAME_LEN 8192 17 #define MAX_METRIC 0xffffffff 18 #define ARITH_SHIFT 8 19 #define LINK_FAIL_THRESH 95 20 21 #define MAX_PREQ_QUEUE_LEN 64 22 23 static void mesh_queue_preq(struct mesh_path *, u8); 24 25 static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae) 26 { 27 if (ae) 28 offset += 6; 29 return get_unaligned_le32(preq_elem + offset); 30 } 31 32 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae) 33 { 34 if (ae) 35 offset += 6; 36 return get_unaligned_le16(preq_elem + offset); 37 } 38 39 /* HWMP IE processing macros */ 40 #define AE_F (1<<6) 41 #define AE_F_SET(x) (*x & AE_F) 42 #define PREQ_IE_FLAGS(x) (*(x)) 43 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 44 #define PREQ_IE_TTL(x) (*(x + 2)) 45 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 46 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 47 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0) 48 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)) 49 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)) 50 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 51 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 52 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)) 53 54 55 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 56 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 57 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 58 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 59 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x)) 60 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)) 61 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)) 62 #define PREP_IE_TARGET_ADDR(x) (x + 3) 63 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 64 65 #define PERR_IE_TTL(x) (*(x)) 66 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 67 #define PERR_IE_TARGET_ADDR(x) (x + 3) 68 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 69 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) 70 71 #define MSEC_TO_TU(x) (x*1000/1024) 72 #define SN_GT(x, y) ((s32)(y - x) < 0) 73 #define SN_LT(x, y) ((s32)(x - y) < 0) 74 #define MAX_SANE_SN_DELTA 32 75 76 static inline u32 SN_DELTA(u32 x, u32 y) 77 { 78 return x >= y ? x - y : y - x; 79 } 80 81 #define net_traversal_jiffies(s) \ 82 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 83 #define default_lifetime(s) \ 84 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 85 #define min_preq_int_jiff(s) \ 86 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 87 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 88 #define disc_timeout_jiff(s) \ 89 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 90 #define root_path_confirmation_jiffies(s) \ 91 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval) 92 93 enum mpath_frame_type { 94 MPATH_PREQ = 0, 95 MPATH_PREP, 96 MPATH_PERR, 97 MPATH_RANN 98 }; 99 100 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 101 102 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 103 const u8 *orig_addr, u32 orig_sn, 104 u8 target_flags, const u8 *target, 105 u32 target_sn, const u8 *da, 106 u8 hop_count, u8 ttl, 107 u32 lifetime, u32 metric, u32 preq_id, 108 struct ieee80211_sub_if_data *sdata) 109 { 110 struct ieee80211_local *local = sdata->local; 111 struct sk_buff *skb; 112 struct ieee80211_mgmt *mgmt; 113 u8 *pos, ie_len; 114 int hdr_len = offsetofend(struct ieee80211_mgmt, 115 u.action.u.mesh_action); 116 117 skb = dev_alloc_skb(local->tx_headroom + 118 hdr_len + 119 2 + 37); /* max HWMP IE */ 120 if (!skb) 121 return -1; 122 skb_reserve(skb, local->tx_headroom); 123 mgmt = skb_put_zero(skb, hdr_len); 124 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 125 IEEE80211_STYPE_ACTION); 126 127 memcpy(mgmt->da, da, ETH_ALEN); 128 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 129 /* BSSID == SA */ 130 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 131 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 132 mgmt->u.action.u.mesh_action.action_code = 133 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 134 135 switch (action) { 136 case MPATH_PREQ: 137 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target); 138 ie_len = 37; 139 pos = skb_put(skb, 2 + ie_len); 140 *pos++ = WLAN_EID_PREQ; 141 break; 142 case MPATH_PREP: 143 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr); 144 ie_len = 31; 145 pos = skb_put(skb, 2 + ie_len); 146 *pos++ = WLAN_EID_PREP; 147 break; 148 case MPATH_RANN: 149 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr); 150 ie_len = sizeof(struct ieee80211_rann_ie); 151 pos = skb_put(skb, 2 + ie_len); 152 *pos++ = WLAN_EID_RANN; 153 break; 154 default: 155 kfree_skb(skb); 156 return -ENOTSUPP; 157 } 158 *pos++ = ie_len; 159 *pos++ = flags; 160 *pos++ = hop_count; 161 *pos++ = ttl; 162 if (action == MPATH_PREP) { 163 memcpy(pos, target, ETH_ALEN); 164 pos += ETH_ALEN; 165 put_unaligned_le32(target_sn, pos); 166 pos += 4; 167 } else { 168 if (action == MPATH_PREQ) { 169 put_unaligned_le32(preq_id, pos); 170 pos += 4; 171 } 172 memcpy(pos, orig_addr, ETH_ALEN); 173 pos += ETH_ALEN; 174 put_unaligned_le32(orig_sn, pos); 175 pos += 4; 176 } 177 put_unaligned_le32(lifetime, pos); /* interval for RANN */ 178 pos += 4; 179 put_unaligned_le32(metric, pos); 180 pos += 4; 181 if (action == MPATH_PREQ) { 182 *pos++ = 1; /* destination count */ 183 *pos++ = target_flags; 184 memcpy(pos, target, ETH_ALEN); 185 pos += ETH_ALEN; 186 put_unaligned_le32(target_sn, pos); 187 pos += 4; 188 } else if (action == MPATH_PREP) { 189 memcpy(pos, orig_addr, ETH_ALEN); 190 pos += ETH_ALEN; 191 put_unaligned_le32(orig_sn, pos); 192 pos += 4; 193 } 194 195 ieee80211_tx_skb(sdata, skb); 196 return 0; 197 } 198 199 200 /* Headroom is not adjusted. Caller should ensure that skb has sufficient 201 * headroom in case the frame is encrypted. */ 202 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, 203 struct sk_buff *skb) 204 { 205 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 206 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 207 208 skb_reset_mac_header(skb); 209 skb_reset_network_header(skb); 210 skb_reset_transport_header(skb); 211 212 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ 213 skb_set_queue_mapping(skb, IEEE80211_AC_VO); 214 skb->priority = 7; 215 216 info->control.vif = &sdata->vif; 217 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 218 ieee80211_set_qos_hdr(sdata, skb); 219 ieee80211_mps_set_frame_flags(sdata, NULL, hdr); 220 } 221 222 /** 223 * mesh_path_error_tx - Sends a PERR mesh management frame 224 * 225 * @ttl: allowed remaining hops 226 * @target: broken destination 227 * @target_sn: SN of the broken destination 228 * @target_rcode: reason code for this PERR 229 * @ra: node this frame is addressed to 230 * @sdata: local mesh subif 231 * 232 * Note: This function may be called with driver locks taken that the driver 233 * also acquires in the TX path. To avoid a deadlock we don't transmit the 234 * frame directly but add it to the pending queue instead. 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 sdata->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 + sdata->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; 303 304 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 305 306 /* moving average, scaled to 100. 307 * feed failure as 100 and success as 0 308 */ 309 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); 310 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 311 LINK_FAIL_THRESH) 312 mesh_plink_broken(sta); 313 } 314 315 static u32 airtime_link_metric_get(struct ieee80211_local *local, 316 struct sta_info *sta) 317 { 318 struct rate_info rinfo; 319 /* This should be adjusted for each device */ 320 int device_constant = 1 << ARITH_SHIFT; 321 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 322 int s_unit = 1 << ARITH_SHIFT; 323 int rate, err; 324 u32 tx_time, estimated_retx; 325 u64 result; 326 unsigned long fail_avg = 327 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 328 329 /* Try to get rate based on HW/SW RC algorithm. 330 * Rate is returned in units of Kbps, correct this 331 * to comply with airtime calculation units 332 * Round up in case we get rate < 100Kbps 333 */ 334 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 335 336 if (rate) { 337 err = 0; 338 } else { 339 if (fail_avg > LINK_FAIL_THRESH) 340 return MAX_METRIC; 341 342 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo); 343 rate = cfg80211_calculate_bitrate(&rinfo); 344 if (WARN_ON(!rate)) 345 return MAX_METRIC; 346 347 err = (fail_avg << ARITH_SHIFT) / 100; 348 } 349 350 /* bitrate is in units of 100 Kbps, while we need rate in units of 351 * 1Mbps. This will be corrected on tx_time computation. 352 */ 353 tx_time = (device_constant + 10 * test_frame_len / rate); 354 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 355 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT); 356 return (u32)result; 357 } 358 359 /** 360 * hwmp_route_info_get - Update routing info to originator and transmitter 361 * 362 * @sdata: local mesh subif 363 * @mgmt: mesh management frame 364 * @hwmp_ie: hwmp information element (PREP or PREQ) 365 * @action: type of hwmp ie 366 * 367 * This function updates the path routing information to the originator and the 368 * transmitter of a HWMP PREQ or PREP frame. 369 * 370 * Returns: metric to frame originator or 0 if the frame should not be further 371 * processed 372 * 373 * Notes: this function is the only place (besides user-provided info) where 374 * path routing information is updated. 375 */ 376 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 377 struct ieee80211_mgmt *mgmt, 378 const u8 *hwmp_ie, enum mpath_frame_type action) 379 { 380 struct ieee80211_local *local = sdata->local; 381 struct mesh_path *mpath; 382 struct sta_info *sta; 383 bool fresh_info; 384 const u8 *orig_addr, *ta; 385 u32 orig_sn, orig_metric; 386 unsigned long orig_lifetime, exp_time; 387 u32 last_hop_metric, new_metric; 388 bool process = true; 389 390 rcu_read_lock(); 391 sta = sta_info_get(sdata, mgmt->sa); 392 if (!sta) { 393 rcu_read_unlock(); 394 return 0; 395 } 396 397 last_hop_metric = airtime_link_metric_get(local, sta); 398 /* Update and check originator routing info */ 399 fresh_info = true; 400 401 switch (action) { 402 case MPATH_PREQ: 403 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 404 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 405 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 406 orig_metric = PREQ_IE_METRIC(hwmp_ie); 407 break; 408 case MPATH_PREP: 409 /* Originator here refers to the MP that was the target in the 410 * Path Request. We divert from the nomenclature in the draft 411 * so that we can easily use a single function to gather path 412 * information from both PREQ and PREP frames. 413 */ 414 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 415 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 416 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 417 orig_metric = PREP_IE_METRIC(hwmp_ie); 418 break; 419 default: 420 rcu_read_unlock(); 421 return 0; 422 } 423 new_metric = orig_metric + last_hop_metric; 424 if (new_metric < orig_metric) 425 new_metric = MAX_METRIC; 426 exp_time = TU_TO_EXP_TIME(orig_lifetime); 427 428 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 429 /* This MP is the originator, we are not interested in this 430 * frame, except for updating transmitter's path info. 431 */ 432 process = false; 433 fresh_info = false; 434 } else { 435 mpath = mesh_path_lookup(sdata, orig_addr); 436 if (mpath) { 437 spin_lock_bh(&mpath->state_lock); 438 if (mpath->flags & MESH_PATH_FIXED) 439 fresh_info = false; 440 else if ((mpath->flags & MESH_PATH_ACTIVE) && 441 (mpath->flags & MESH_PATH_SN_VALID)) { 442 if (SN_GT(mpath->sn, orig_sn) || 443 (mpath->sn == orig_sn && 444 new_metric >= mpath->metric)) { 445 process = false; 446 fresh_info = false; 447 } 448 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 449 bool have_sn, newer_sn, bounced; 450 451 have_sn = mpath->flags & MESH_PATH_SN_VALID; 452 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 453 bounced = have_sn && 454 (SN_DELTA(orig_sn, mpath->sn) > 455 MAX_SANE_SN_DELTA); 456 457 if (!have_sn || newer_sn) { 458 /* if SN is newer than what we had 459 * then we can take it */; 460 } else if (bounced) { 461 /* if SN is way different than what 462 * we had then assume the other side 463 * rebooted or restarted */; 464 } else { 465 process = false; 466 fresh_info = false; 467 } 468 } 469 } else { 470 mpath = mesh_path_add(sdata, orig_addr); 471 if (IS_ERR(mpath)) { 472 rcu_read_unlock(); 473 return 0; 474 } 475 spin_lock_bh(&mpath->state_lock); 476 } 477 478 if (fresh_info) { 479 mesh_path_assign_nexthop(mpath, sta); 480 mpath->flags |= MESH_PATH_SN_VALID; 481 mpath->metric = new_metric; 482 mpath->sn = orig_sn; 483 mpath->exp_time = time_after(mpath->exp_time, exp_time) 484 ? mpath->exp_time : exp_time; 485 mesh_path_activate(mpath); 486 spin_unlock_bh(&mpath->state_lock); 487 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 488 /* init it at a low value - 0 start is tricky */ 489 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 490 mesh_path_tx_pending(mpath); 491 /* draft says preq_id should be saved to, but there does 492 * not seem to be any use for it, skipping by now 493 */ 494 } else 495 spin_unlock_bh(&mpath->state_lock); 496 } 497 498 /* Update and check transmitter routing info */ 499 ta = mgmt->sa; 500 if (ether_addr_equal(orig_addr, ta)) 501 fresh_info = false; 502 else { 503 fresh_info = true; 504 505 mpath = mesh_path_lookup(sdata, ta); 506 if (mpath) { 507 spin_lock_bh(&mpath->state_lock); 508 if ((mpath->flags & MESH_PATH_FIXED) || 509 ((mpath->flags & MESH_PATH_ACTIVE) && 510 (last_hop_metric > mpath->metric))) 511 fresh_info = false; 512 } else { 513 mpath = mesh_path_add(sdata, ta); 514 if (IS_ERR(mpath)) { 515 rcu_read_unlock(); 516 return 0; 517 } 518 spin_lock_bh(&mpath->state_lock); 519 } 520 521 if (fresh_info) { 522 mesh_path_assign_nexthop(mpath, sta); 523 mpath->metric = last_hop_metric; 524 mpath->exp_time = time_after(mpath->exp_time, exp_time) 525 ? mpath->exp_time : exp_time; 526 mesh_path_activate(mpath); 527 spin_unlock_bh(&mpath->state_lock); 528 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 529 /* init it at a low value - 0 start is tricky */ 530 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 531 mesh_path_tx_pending(mpath); 532 } else 533 spin_unlock_bh(&mpath->state_lock); 534 } 535 536 rcu_read_unlock(); 537 538 return process ? new_metric : 0; 539 } 540 541 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 542 struct ieee80211_mgmt *mgmt, 543 const u8 *preq_elem, u32 orig_metric) 544 { 545 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 546 struct mesh_path *mpath = NULL; 547 const u8 *target_addr, *orig_addr; 548 const u8 *da; 549 u8 target_flags, ttl, flags; 550 u32 orig_sn, target_sn, lifetime, target_metric = 0; 551 bool reply = false; 552 bool forward = true; 553 bool root_is_gate; 554 555 /* Update target SN, if present */ 556 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 557 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 558 target_sn = PREQ_IE_TARGET_SN(preq_elem); 559 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 560 target_flags = PREQ_IE_TARGET_F(preq_elem); 561 /* Proactive PREQ gate announcements */ 562 flags = PREQ_IE_FLAGS(preq_elem); 563 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 564 565 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 566 567 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 568 mhwmp_dbg(sdata, "PREQ is for us\n"); 569 forward = false; 570 reply = true; 571 target_metric = 0; 572 573 if (SN_GT(target_sn, ifmsh->sn)) 574 ifmsh->sn = target_sn; 575 576 if (time_after(jiffies, ifmsh->last_sn_update + 577 net_traversal_jiffies(sdata)) || 578 time_before(jiffies, ifmsh->last_sn_update)) { 579 ++ifmsh->sn; 580 ifmsh->last_sn_update = jiffies; 581 } 582 target_sn = ifmsh->sn; 583 } else if (is_broadcast_ether_addr(target_addr) && 584 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 585 rcu_read_lock(); 586 mpath = mesh_path_lookup(sdata, orig_addr); 587 if (mpath) { 588 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 589 reply = true; 590 target_addr = sdata->vif.addr; 591 target_sn = ++ifmsh->sn; 592 target_metric = 0; 593 ifmsh->last_sn_update = jiffies; 594 } 595 if (root_is_gate) 596 mesh_path_add_gate(mpath); 597 } 598 rcu_read_unlock(); 599 } else { 600 rcu_read_lock(); 601 mpath = mesh_path_lookup(sdata, target_addr); 602 if (mpath) { 603 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 604 SN_LT(mpath->sn, target_sn)) { 605 mpath->sn = target_sn; 606 mpath->flags |= MESH_PATH_SN_VALID; 607 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 608 (mpath->flags & MESH_PATH_ACTIVE)) { 609 reply = true; 610 target_metric = mpath->metric; 611 target_sn = mpath->sn; 612 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 613 target_flags |= IEEE80211_PREQ_TO_FLAG; 614 } 615 } 616 rcu_read_unlock(); 617 } 618 619 if (reply) { 620 lifetime = PREQ_IE_LIFETIME(preq_elem); 621 ttl = ifmsh->mshcfg.element_ttl; 622 if (ttl != 0) { 623 mhwmp_dbg(sdata, "replying to the PREQ\n"); 624 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 625 orig_sn, 0, target_addr, 626 target_sn, mgmt->sa, 0, ttl, 627 lifetime, target_metric, 0, 628 sdata); 629 } else { 630 ifmsh->mshstats.dropped_frames_ttl++; 631 } 632 } 633 634 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 635 u32 preq_id; 636 u8 hopcount; 637 638 ttl = PREQ_IE_TTL(preq_elem); 639 lifetime = PREQ_IE_LIFETIME(preq_elem); 640 if (ttl <= 1) { 641 ifmsh->mshstats.dropped_frames_ttl++; 642 return; 643 } 644 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 645 --ttl; 646 preq_id = PREQ_IE_PREQ_ID(preq_elem); 647 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 648 da = (mpath && mpath->is_root) ? 649 mpath->rann_snd_addr : broadcast_addr; 650 651 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 652 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 653 target_sn = PREQ_IE_TARGET_SN(preq_elem); 654 } 655 656 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 657 orig_sn, target_flags, target_addr, 658 target_sn, da, hopcount, ttl, lifetime, 659 orig_metric, preq_id, sdata); 660 if (!is_multicast_ether_addr(da)) 661 ifmsh->mshstats.fwded_unicast++; 662 else 663 ifmsh->mshstats.fwded_mcast++; 664 ifmsh->mshstats.fwded_frames++; 665 } 666 } 667 668 669 static inline struct sta_info * 670 next_hop_deref_protected(struct mesh_path *mpath) 671 { 672 return rcu_dereference_protected(mpath->next_hop, 673 lockdep_is_held(&mpath->state_lock)); 674 } 675 676 677 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 678 struct ieee80211_mgmt *mgmt, 679 const u8 *prep_elem, u32 metric) 680 { 681 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 682 struct mesh_path *mpath; 683 const u8 *target_addr, *orig_addr; 684 u8 ttl, hopcount, flags; 685 u8 next_hop[ETH_ALEN]; 686 u32 target_sn, orig_sn, lifetime; 687 688 mhwmp_dbg(sdata, "received PREP from %pM\n", 689 PREP_IE_TARGET_ADDR(prep_elem)); 690 691 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 692 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 693 /* destination, no forwarding required */ 694 return; 695 696 if (!ifmsh->mshcfg.dot11MeshForwarding) 697 return; 698 699 ttl = PREP_IE_TTL(prep_elem); 700 if (ttl <= 1) { 701 sdata->u.mesh.mshstats.dropped_frames_ttl++; 702 return; 703 } 704 705 rcu_read_lock(); 706 mpath = mesh_path_lookup(sdata, orig_addr); 707 if (mpath) 708 spin_lock_bh(&mpath->state_lock); 709 else 710 goto fail; 711 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 712 spin_unlock_bh(&mpath->state_lock); 713 goto fail; 714 } 715 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 716 spin_unlock_bh(&mpath->state_lock); 717 --ttl; 718 flags = PREP_IE_FLAGS(prep_elem); 719 lifetime = PREP_IE_LIFETIME(prep_elem); 720 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 721 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 722 target_sn = PREP_IE_TARGET_SN(prep_elem); 723 orig_sn = PREP_IE_ORIG_SN(prep_elem); 724 725 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 726 target_addr, target_sn, next_hop, hopcount, 727 ttl, lifetime, metric, 0, sdata); 728 rcu_read_unlock(); 729 730 sdata->u.mesh.mshstats.fwded_unicast++; 731 sdata->u.mesh.mshstats.fwded_frames++; 732 return; 733 734 fail: 735 rcu_read_unlock(); 736 sdata->u.mesh.mshstats.dropped_frames_no_route++; 737 } 738 739 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 740 struct ieee80211_mgmt *mgmt, 741 const u8 *perr_elem) 742 { 743 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 744 struct mesh_path *mpath; 745 u8 ttl; 746 const u8 *ta, *target_addr; 747 u32 target_sn; 748 u16 target_rcode; 749 750 ta = mgmt->sa; 751 ttl = PERR_IE_TTL(perr_elem); 752 if (ttl <= 1) { 753 ifmsh->mshstats.dropped_frames_ttl++; 754 return; 755 } 756 ttl--; 757 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 758 target_sn = PERR_IE_TARGET_SN(perr_elem); 759 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 760 761 rcu_read_lock(); 762 mpath = mesh_path_lookup(sdata, target_addr); 763 if (mpath) { 764 struct sta_info *sta; 765 766 spin_lock_bh(&mpath->state_lock); 767 sta = next_hop_deref_protected(mpath); 768 if (mpath->flags & MESH_PATH_ACTIVE && 769 ether_addr_equal(ta, sta->sta.addr) && 770 !(mpath->flags & MESH_PATH_FIXED) && 771 (!(mpath->flags & MESH_PATH_SN_VALID) || 772 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 773 mpath->flags &= ~MESH_PATH_ACTIVE; 774 if (target_sn != 0) 775 mpath->sn = target_sn; 776 else 777 mpath->sn += 1; 778 spin_unlock_bh(&mpath->state_lock); 779 if (!ifmsh->mshcfg.dot11MeshForwarding) 780 goto endperr; 781 mesh_path_error_tx(sdata, ttl, target_addr, 782 target_sn, target_rcode, 783 broadcast_addr); 784 } else 785 spin_unlock_bh(&mpath->state_lock); 786 } 787 endperr: 788 rcu_read_unlock(); 789 } 790 791 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 792 struct ieee80211_mgmt *mgmt, 793 const struct ieee80211_rann_ie *rann) 794 { 795 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 796 struct ieee80211_local *local = sdata->local; 797 struct sta_info *sta; 798 struct mesh_path *mpath; 799 u8 ttl, flags, hopcount; 800 const u8 *orig_addr; 801 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; 802 bool root_is_gate; 803 804 ttl = rann->rann_ttl; 805 flags = rann->rann_flags; 806 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 807 orig_addr = rann->rann_addr; 808 orig_sn = le32_to_cpu(rann->rann_seq); 809 interval = le32_to_cpu(rann->rann_interval); 810 hopcount = rann->rann_hopcount; 811 hopcount++; 812 orig_metric = le32_to_cpu(rann->rann_metric); 813 814 /* Ignore our own RANNs */ 815 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 816 return; 817 818 mhwmp_dbg(sdata, 819 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 820 orig_addr, mgmt->sa, root_is_gate); 821 822 rcu_read_lock(); 823 sta = sta_info_get(sdata, mgmt->sa); 824 if (!sta) { 825 rcu_read_unlock(); 826 return; 827 } 828 829 last_hop_metric = airtime_link_metric_get(local, sta); 830 new_metric = orig_metric + last_hop_metric; 831 if (new_metric < orig_metric) 832 new_metric = MAX_METRIC; 833 834 mpath = mesh_path_lookup(sdata, orig_addr); 835 if (!mpath) { 836 mpath = mesh_path_add(sdata, orig_addr); 837 if (IS_ERR(mpath)) { 838 rcu_read_unlock(); 839 sdata->u.mesh.mshstats.dropped_frames_no_route++; 840 return; 841 } 842 } 843 844 if (!(SN_LT(mpath->sn, orig_sn)) && 845 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { 846 rcu_read_unlock(); 847 return; 848 } 849 850 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 851 (time_after(jiffies, mpath->last_preq_to_root + 852 root_path_confirmation_jiffies(sdata)) || 853 time_before(jiffies, mpath->last_preq_to_root))) && 854 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 855 mhwmp_dbg(sdata, 856 "time to refresh root mpath %pM\n", 857 orig_addr); 858 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 859 mpath->last_preq_to_root = jiffies; 860 } 861 862 mpath->sn = orig_sn; 863 mpath->rann_metric = new_metric; 864 mpath->is_root = true; 865 /* Recording RANNs sender address to send individually 866 * addressed PREQs destined for root mesh STA */ 867 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 868 869 if (root_is_gate) 870 mesh_path_add_gate(mpath); 871 872 if (ttl <= 1) { 873 ifmsh->mshstats.dropped_frames_ttl++; 874 rcu_read_unlock(); 875 return; 876 } 877 ttl--; 878 879 if (ifmsh->mshcfg.dot11MeshForwarding) { 880 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 881 orig_sn, 0, NULL, 0, broadcast_addr, 882 hopcount, ttl, interval, 883 new_metric, 0, sdata); 884 } 885 886 rcu_read_unlock(); 887 } 888 889 890 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 891 struct ieee80211_mgmt *mgmt, size_t len) 892 { 893 struct ieee802_11_elems elems; 894 size_t baselen; 895 u32 path_metric; 896 struct sta_info *sta; 897 898 /* need action_code */ 899 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 900 return; 901 902 rcu_read_lock(); 903 sta = sta_info_get(sdata, mgmt->sa); 904 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 905 rcu_read_unlock(); 906 return; 907 } 908 rcu_read_unlock(); 909 910 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 911 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 912 len - baselen, false, &elems); 913 914 if (elems.preq) { 915 if (elems.preq_len != 37) 916 /* Right now we support just 1 destination and no AE */ 917 return; 918 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 919 MPATH_PREQ); 920 if (path_metric) 921 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 922 path_metric); 923 } 924 if (elems.prep) { 925 if (elems.prep_len != 31) 926 /* Right now we support no AE */ 927 return; 928 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 929 MPATH_PREP); 930 if (path_metric) 931 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 932 path_metric); 933 } 934 if (elems.perr) { 935 if (elems.perr_len != 15) 936 /* Right now we support only one destination per PERR */ 937 return; 938 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 939 } 940 if (elems.rann) 941 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 942 } 943 944 /** 945 * mesh_queue_preq - queue a PREQ to a given destination 946 * 947 * @mpath: mesh path to discover 948 * @flags: special attributes of the PREQ to be sent 949 * 950 * Locking: the function must be called from within a rcu read lock block. 951 * 952 */ 953 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 954 { 955 struct ieee80211_sub_if_data *sdata = mpath->sdata; 956 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 957 struct mesh_preq_queue *preq_node; 958 959 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 960 if (!preq_node) { 961 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 962 return; 963 } 964 965 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 966 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 967 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 968 kfree(preq_node); 969 if (printk_ratelimit()) 970 mhwmp_dbg(sdata, "PREQ node queue full\n"); 971 return; 972 } 973 974 spin_lock(&mpath->state_lock); 975 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 976 spin_unlock(&mpath->state_lock); 977 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 978 kfree(preq_node); 979 return; 980 } 981 982 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 983 preq_node->flags = flags; 984 985 mpath->flags |= MESH_PATH_REQ_QUEUED; 986 spin_unlock(&mpath->state_lock); 987 988 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 989 ++ifmsh->preq_queue_len; 990 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 991 992 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 993 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 994 995 else if (time_before(jiffies, ifmsh->last_preq)) { 996 /* avoid long wait if did not send preqs for a long time 997 * and jiffies wrapped around 998 */ 999 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 1000 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1001 } else 1002 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 1003 min_preq_int_jiff(sdata)); 1004 } 1005 1006 /** 1007 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1008 * 1009 * @sdata: local mesh subif 1010 */ 1011 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1012 { 1013 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1014 struct mesh_preq_queue *preq_node; 1015 struct mesh_path *mpath; 1016 u8 ttl, target_flags = 0; 1017 const u8 *da; 1018 u32 lifetime; 1019 1020 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1021 if (!ifmsh->preq_queue_len || 1022 time_before(jiffies, ifmsh->last_preq + 1023 min_preq_int_jiff(sdata))) { 1024 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1025 return; 1026 } 1027 1028 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1029 struct mesh_preq_queue, list); 1030 list_del(&preq_node->list); 1031 --ifmsh->preq_queue_len; 1032 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1033 1034 rcu_read_lock(); 1035 mpath = mesh_path_lookup(sdata, preq_node->dst); 1036 if (!mpath) 1037 goto enddiscovery; 1038 1039 spin_lock_bh(&mpath->state_lock); 1040 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1041 spin_unlock_bh(&mpath->state_lock); 1042 goto enddiscovery; 1043 } 1044 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1045 if (preq_node->flags & PREQ_Q_F_START) { 1046 if (mpath->flags & MESH_PATH_RESOLVING) { 1047 spin_unlock_bh(&mpath->state_lock); 1048 goto enddiscovery; 1049 } else { 1050 mpath->flags &= ~MESH_PATH_RESOLVED; 1051 mpath->flags |= MESH_PATH_RESOLVING; 1052 mpath->discovery_retries = 0; 1053 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1054 } 1055 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1056 mpath->flags & MESH_PATH_RESOLVED) { 1057 mpath->flags &= ~MESH_PATH_RESOLVING; 1058 spin_unlock_bh(&mpath->state_lock); 1059 goto enddiscovery; 1060 } 1061 1062 ifmsh->last_preq = jiffies; 1063 1064 if (time_after(jiffies, ifmsh->last_sn_update + 1065 net_traversal_jiffies(sdata)) || 1066 time_before(jiffies, ifmsh->last_sn_update)) { 1067 ++ifmsh->sn; 1068 sdata->u.mesh.last_sn_update = jiffies; 1069 } 1070 lifetime = default_lifetime(sdata); 1071 ttl = sdata->u.mesh.mshcfg.element_ttl; 1072 if (ttl == 0) { 1073 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1074 spin_unlock_bh(&mpath->state_lock); 1075 goto enddiscovery; 1076 } 1077 1078 if (preq_node->flags & PREQ_Q_F_REFRESH) 1079 target_flags |= IEEE80211_PREQ_TO_FLAG; 1080 else 1081 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1082 1083 spin_unlock_bh(&mpath->state_lock); 1084 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1085 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1086 target_flags, mpath->dst, mpath->sn, da, 0, 1087 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1088 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1089 1090 enddiscovery: 1091 rcu_read_unlock(); 1092 kfree(preq_node); 1093 } 1094 1095 /** 1096 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1097 * 1098 * @skb: 802.11 frame to be sent 1099 * @sdata: network subif the frame will be sent through 1100 * 1101 * Lookup next hop for given skb and start path discovery if no 1102 * forwarding information is found. 1103 * 1104 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1105 * skb is freeed here if no mpath could be allocated. 1106 */ 1107 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1108 struct sk_buff *skb) 1109 { 1110 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1111 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1112 struct mesh_path *mpath; 1113 struct sk_buff *skb_to_free = NULL; 1114 u8 *target_addr = hdr->addr3; 1115 int err = 0; 1116 1117 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1118 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1119 return 0; 1120 1121 rcu_read_lock(); 1122 err = mesh_nexthop_lookup(sdata, skb); 1123 if (!err) 1124 goto endlookup; 1125 1126 /* no nexthop found, start resolving */ 1127 mpath = mesh_path_lookup(sdata, target_addr); 1128 if (!mpath) { 1129 mpath = mesh_path_add(sdata, target_addr); 1130 if (IS_ERR(mpath)) { 1131 mesh_path_discard_frame(sdata, skb); 1132 err = PTR_ERR(mpath); 1133 goto endlookup; 1134 } 1135 } 1136 1137 if (!(mpath->flags & MESH_PATH_RESOLVING)) 1138 mesh_queue_preq(mpath, PREQ_Q_F_START); 1139 1140 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1141 skb_to_free = skb_dequeue(&mpath->frame_queue); 1142 1143 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 1144 ieee80211_set_qos_hdr(sdata, skb); 1145 skb_queue_tail(&mpath->frame_queue, skb); 1146 err = -ENOENT; 1147 if (skb_to_free) 1148 mesh_path_discard_frame(sdata, skb_to_free); 1149 1150 endlookup: 1151 rcu_read_unlock(); 1152 return err; 1153 } 1154 1155 /** 1156 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1157 * this function is considered "using" the associated mpath, so preempt a path 1158 * refresh if this mpath expires soon. 1159 * 1160 * @skb: 802.11 frame to be sent 1161 * @sdata: network subif the frame will be sent through 1162 * 1163 * Returns: 0 if the next hop was found. Nonzero otherwise. 1164 */ 1165 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1166 struct sk_buff *skb) 1167 { 1168 struct mesh_path *mpath; 1169 struct sta_info *next_hop; 1170 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1171 u8 *target_addr = hdr->addr3; 1172 int err = -ENOENT; 1173 1174 rcu_read_lock(); 1175 mpath = mesh_path_lookup(sdata, target_addr); 1176 1177 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1178 goto endlookup; 1179 1180 if (time_after(jiffies, 1181 mpath->exp_time - 1182 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1183 ether_addr_equal(sdata->vif.addr, hdr->addr4) && 1184 !(mpath->flags & MESH_PATH_RESOLVING) && 1185 !(mpath->flags & MESH_PATH_FIXED)) 1186 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1187 1188 next_hop = rcu_dereference(mpath->next_hop); 1189 if (next_hop) { 1190 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1191 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1192 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1193 err = 0; 1194 } 1195 1196 endlookup: 1197 rcu_read_unlock(); 1198 return err; 1199 } 1200 1201 void mesh_path_timer(struct timer_list *t) 1202 { 1203 struct mesh_path *mpath = from_timer(mpath, t, timer); 1204 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1205 int ret; 1206 1207 if (sdata->local->quiescing) 1208 return; 1209 1210 spin_lock_bh(&mpath->state_lock); 1211 if (mpath->flags & MESH_PATH_RESOLVED || 1212 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1213 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1214 spin_unlock_bh(&mpath->state_lock); 1215 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1216 ++mpath->discovery_retries; 1217 mpath->discovery_timeout *= 2; 1218 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1219 spin_unlock_bh(&mpath->state_lock); 1220 mesh_queue_preq(mpath, 0); 1221 } else { 1222 mpath->flags &= ~(MESH_PATH_RESOLVING | 1223 MESH_PATH_RESOLVED | 1224 MESH_PATH_REQ_QUEUED); 1225 mpath->exp_time = jiffies; 1226 spin_unlock_bh(&mpath->state_lock); 1227 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1228 ret = mesh_path_send_to_gates(mpath); 1229 if (ret) 1230 mhwmp_dbg(sdata, "no gate was reachable\n"); 1231 } else 1232 mesh_path_flush_pending(mpath); 1233 } 1234 } 1235 1236 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1237 { 1238 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1239 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1240 u8 flags, target_flags = 0; 1241 1242 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1243 ? RANN_FLAG_IS_GATE : 0; 1244 1245 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1246 case IEEE80211_PROACTIVE_RANN: 1247 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1248 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1249 0, ifmsh->mshcfg.element_ttl, 1250 interval, 0, 0, sdata); 1251 break; 1252 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1253 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1254 /* fall through */ 1255 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1256 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1257 target_flags |= IEEE80211_PREQ_TO_FLAG | 1258 IEEE80211_PREQ_USN_FLAG; 1259 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1260 ++ifmsh->sn, target_flags, 1261 (u8 *) broadcast_addr, 0, broadcast_addr, 1262 0, ifmsh->mshcfg.element_ttl, interval, 1263 0, ifmsh->preq_id++, sdata); 1264 break; 1265 default: 1266 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1267 return; 1268 } 1269 } 1270