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 = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + 115 sizeof(mgmt->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 = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + 246 sizeof(mgmt->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, struct sk_buff *skb) 299 { 300 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); 301 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 302 int failed; 303 304 if (!ieee80211_is_data(hdr->frame_control)) 305 return; 306 307 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 308 309 /* moving average, scaled to 100. 310 * feed failure as 100 and success as 0 311 */ 312 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); 313 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 314 LINK_FAIL_THRESH) 315 mesh_plink_broken(sta); 316 } 317 318 static u32 airtime_link_metric_get(struct ieee80211_local *local, 319 struct sta_info *sta) 320 { 321 struct rate_info rinfo; 322 /* This should be adjusted for each device */ 323 int device_constant = 1 << ARITH_SHIFT; 324 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 325 int s_unit = 1 << ARITH_SHIFT; 326 int rate, err; 327 u32 tx_time, estimated_retx; 328 u64 result; 329 unsigned long fail_avg = 330 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 331 332 /* Try to get rate based on HW/SW RC algorithm. 333 * Rate is returned in units of Kbps, correct this 334 * to comply with airtime calculation units 335 * Round up in case we get rate < 100Kbps 336 */ 337 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 338 339 if (rate) { 340 err = 0; 341 } else { 342 if (fail_avg > LINK_FAIL_THRESH) 343 return MAX_METRIC; 344 345 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo); 346 rate = cfg80211_calculate_bitrate(&rinfo); 347 if (WARN_ON(!rate)) 348 return MAX_METRIC; 349 350 err = (fail_avg << ARITH_SHIFT) / 100; 351 } 352 353 /* bitrate is in units of 100 Kbps, while we need rate in units of 354 * 1Mbps. This will be corrected on tx_time computation. 355 */ 356 tx_time = (device_constant + 10 * test_frame_len / rate); 357 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 358 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT); 359 return (u32)result; 360 } 361 362 /** 363 * hwmp_route_info_get - Update routing info to originator and transmitter 364 * 365 * @sdata: local mesh subif 366 * @mgmt: mesh management frame 367 * @hwmp_ie: hwmp information element (PREP or PREQ) 368 * @action: type of hwmp ie 369 * 370 * This function updates the path routing information to the originator and the 371 * transmitter of a HWMP PREQ or PREP frame. 372 * 373 * Returns: metric to frame originator or 0 if the frame should not be further 374 * processed 375 * 376 * Notes: this function is the only place (besides user-provided info) where 377 * path routing information is updated. 378 */ 379 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 380 struct ieee80211_mgmt *mgmt, 381 const u8 *hwmp_ie, enum mpath_frame_type action) 382 { 383 struct ieee80211_local *local = sdata->local; 384 struct mesh_path *mpath; 385 struct sta_info *sta; 386 bool fresh_info; 387 const u8 *orig_addr, *ta; 388 u32 orig_sn, orig_metric; 389 unsigned long orig_lifetime, exp_time; 390 u32 last_hop_metric, new_metric; 391 bool process = true; 392 393 rcu_read_lock(); 394 sta = sta_info_get(sdata, mgmt->sa); 395 if (!sta) { 396 rcu_read_unlock(); 397 return 0; 398 } 399 400 last_hop_metric = airtime_link_metric_get(local, sta); 401 /* Update and check originator routing info */ 402 fresh_info = true; 403 404 switch (action) { 405 case MPATH_PREQ: 406 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 407 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 408 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 409 orig_metric = PREQ_IE_METRIC(hwmp_ie); 410 break; 411 case MPATH_PREP: 412 /* Originator here refers to the MP that was the target in the 413 * Path Request. We divert from the nomenclature in the draft 414 * so that we can easily use a single function to gather path 415 * information from both PREQ and PREP frames. 416 */ 417 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 418 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 419 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 420 orig_metric = PREP_IE_METRIC(hwmp_ie); 421 break; 422 default: 423 rcu_read_unlock(); 424 return 0; 425 } 426 new_metric = orig_metric + last_hop_metric; 427 if (new_metric < orig_metric) 428 new_metric = MAX_METRIC; 429 exp_time = TU_TO_EXP_TIME(orig_lifetime); 430 431 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 432 /* This MP is the originator, we are not interested in this 433 * frame, except for updating transmitter's path info. 434 */ 435 process = false; 436 fresh_info = false; 437 } else { 438 mpath = mesh_path_lookup(sdata, orig_addr); 439 if (mpath) { 440 spin_lock_bh(&mpath->state_lock); 441 if (mpath->flags & MESH_PATH_FIXED) 442 fresh_info = false; 443 else if ((mpath->flags & MESH_PATH_ACTIVE) && 444 (mpath->flags & MESH_PATH_SN_VALID)) { 445 if (SN_GT(mpath->sn, orig_sn) || 446 (mpath->sn == orig_sn && 447 new_metric >= mpath->metric)) { 448 process = false; 449 fresh_info = false; 450 } 451 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 452 bool have_sn, newer_sn, bounced; 453 454 have_sn = mpath->flags & MESH_PATH_SN_VALID; 455 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 456 bounced = have_sn && 457 (SN_DELTA(orig_sn, mpath->sn) > 458 MAX_SANE_SN_DELTA); 459 460 if (!have_sn || newer_sn) { 461 /* if SN is newer than what we had 462 * then we can take it */; 463 } else if (bounced) { 464 /* if SN is way different than what 465 * we had then assume the other side 466 * rebooted or restarted */; 467 } else { 468 process = false; 469 fresh_info = false; 470 } 471 } 472 } else { 473 mpath = mesh_path_add(sdata, orig_addr); 474 if (IS_ERR(mpath)) { 475 rcu_read_unlock(); 476 return 0; 477 } 478 spin_lock_bh(&mpath->state_lock); 479 } 480 481 if (fresh_info) { 482 mesh_path_assign_nexthop(mpath, sta); 483 mpath->flags |= MESH_PATH_SN_VALID; 484 mpath->metric = new_metric; 485 mpath->sn = orig_sn; 486 mpath->exp_time = time_after(mpath->exp_time, exp_time) 487 ? mpath->exp_time : exp_time; 488 mesh_path_activate(mpath); 489 spin_unlock_bh(&mpath->state_lock); 490 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 491 /* init it at a low value - 0 start is tricky */ 492 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 493 mesh_path_tx_pending(mpath); 494 /* draft says preq_id should be saved to, but there does 495 * not seem to be any use for it, skipping by now 496 */ 497 } else 498 spin_unlock_bh(&mpath->state_lock); 499 } 500 501 /* Update and check transmitter routing info */ 502 ta = mgmt->sa; 503 if (ether_addr_equal(orig_addr, ta)) 504 fresh_info = false; 505 else { 506 fresh_info = true; 507 508 mpath = mesh_path_lookup(sdata, ta); 509 if (mpath) { 510 spin_lock_bh(&mpath->state_lock); 511 if ((mpath->flags & MESH_PATH_FIXED) || 512 ((mpath->flags & MESH_PATH_ACTIVE) && 513 (last_hop_metric > mpath->metric))) 514 fresh_info = false; 515 } else { 516 mpath = mesh_path_add(sdata, ta); 517 if (IS_ERR(mpath)) { 518 rcu_read_unlock(); 519 return 0; 520 } 521 spin_lock_bh(&mpath->state_lock); 522 } 523 524 if (fresh_info) { 525 mesh_path_assign_nexthop(mpath, sta); 526 mpath->metric = last_hop_metric; 527 mpath->exp_time = time_after(mpath->exp_time, exp_time) 528 ? mpath->exp_time : exp_time; 529 mesh_path_activate(mpath); 530 spin_unlock_bh(&mpath->state_lock); 531 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 532 /* init it at a low value - 0 start is tricky */ 533 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 534 mesh_path_tx_pending(mpath); 535 } else 536 spin_unlock_bh(&mpath->state_lock); 537 } 538 539 rcu_read_unlock(); 540 541 return process ? new_metric : 0; 542 } 543 544 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 545 struct ieee80211_mgmt *mgmt, 546 const u8 *preq_elem, u32 orig_metric) 547 { 548 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 549 struct mesh_path *mpath = NULL; 550 const u8 *target_addr, *orig_addr; 551 const u8 *da; 552 u8 target_flags, ttl, flags; 553 u32 orig_sn, target_sn, lifetime, target_metric = 0; 554 bool reply = false; 555 bool forward = true; 556 bool root_is_gate; 557 558 /* Update target SN, if present */ 559 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 560 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 561 target_sn = PREQ_IE_TARGET_SN(preq_elem); 562 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 563 target_flags = PREQ_IE_TARGET_F(preq_elem); 564 /* Proactive PREQ gate announcements */ 565 flags = PREQ_IE_FLAGS(preq_elem); 566 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 567 568 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 569 570 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 571 mhwmp_dbg(sdata, "PREQ is for us\n"); 572 forward = false; 573 reply = true; 574 target_metric = 0; 575 if (time_after(jiffies, ifmsh->last_sn_update + 576 net_traversal_jiffies(sdata)) || 577 time_before(jiffies, ifmsh->last_sn_update)) { 578 ++ifmsh->sn; 579 ifmsh->last_sn_update = jiffies; 580 } 581 target_sn = ifmsh->sn; 582 } else if (is_broadcast_ether_addr(target_addr) && 583 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 584 rcu_read_lock(); 585 mpath = mesh_path_lookup(sdata, orig_addr); 586 if (mpath) { 587 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 588 reply = true; 589 target_addr = sdata->vif.addr; 590 target_sn = ++ifmsh->sn; 591 target_metric = 0; 592 ifmsh->last_sn_update = jiffies; 593 } 594 if (root_is_gate) 595 mesh_path_add_gate(mpath); 596 } 597 rcu_read_unlock(); 598 } else { 599 rcu_read_lock(); 600 mpath = mesh_path_lookup(sdata, target_addr); 601 if (mpath) { 602 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 603 SN_LT(mpath->sn, target_sn)) { 604 mpath->sn = target_sn; 605 mpath->flags |= MESH_PATH_SN_VALID; 606 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 607 (mpath->flags & MESH_PATH_ACTIVE)) { 608 reply = true; 609 target_metric = mpath->metric; 610 target_sn = mpath->sn; 611 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 612 target_flags |= IEEE80211_PREQ_TO_FLAG; 613 } 614 } 615 rcu_read_unlock(); 616 } 617 618 if (reply) { 619 lifetime = PREQ_IE_LIFETIME(preq_elem); 620 ttl = ifmsh->mshcfg.element_ttl; 621 if (ttl != 0) { 622 mhwmp_dbg(sdata, "replying to the PREQ\n"); 623 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 624 orig_sn, 0, target_addr, 625 target_sn, mgmt->sa, 0, ttl, 626 lifetime, target_metric, 0, 627 sdata); 628 } else { 629 ifmsh->mshstats.dropped_frames_ttl++; 630 } 631 } 632 633 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 634 u32 preq_id; 635 u8 hopcount; 636 637 ttl = PREQ_IE_TTL(preq_elem); 638 lifetime = PREQ_IE_LIFETIME(preq_elem); 639 if (ttl <= 1) { 640 ifmsh->mshstats.dropped_frames_ttl++; 641 return; 642 } 643 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 644 --ttl; 645 preq_id = PREQ_IE_PREQ_ID(preq_elem); 646 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 647 da = (mpath && mpath->is_root) ? 648 mpath->rann_snd_addr : broadcast_addr; 649 650 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 651 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 652 target_sn = PREQ_IE_TARGET_SN(preq_elem); 653 } 654 655 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 656 orig_sn, target_flags, target_addr, 657 target_sn, da, hopcount, ttl, lifetime, 658 orig_metric, preq_id, sdata); 659 if (!is_multicast_ether_addr(da)) 660 ifmsh->mshstats.fwded_unicast++; 661 else 662 ifmsh->mshstats.fwded_mcast++; 663 ifmsh->mshstats.fwded_frames++; 664 } 665 } 666 667 668 static inline struct sta_info * 669 next_hop_deref_protected(struct mesh_path *mpath) 670 { 671 return rcu_dereference_protected(mpath->next_hop, 672 lockdep_is_held(&mpath->state_lock)); 673 } 674 675 676 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 677 struct ieee80211_mgmt *mgmt, 678 const u8 *prep_elem, u32 metric) 679 { 680 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 681 struct mesh_path *mpath; 682 const u8 *target_addr, *orig_addr; 683 u8 ttl, hopcount, flags; 684 u8 next_hop[ETH_ALEN]; 685 u32 target_sn, orig_sn, lifetime; 686 687 mhwmp_dbg(sdata, "received PREP from %pM\n", 688 PREP_IE_TARGET_ADDR(prep_elem)); 689 690 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 691 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 692 /* destination, no forwarding required */ 693 return; 694 695 if (!ifmsh->mshcfg.dot11MeshForwarding) 696 return; 697 698 ttl = PREP_IE_TTL(prep_elem); 699 if (ttl <= 1) { 700 sdata->u.mesh.mshstats.dropped_frames_ttl++; 701 return; 702 } 703 704 rcu_read_lock(); 705 mpath = mesh_path_lookup(sdata, orig_addr); 706 if (mpath) 707 spin_lock_bh(&mpath->state_lock); 708 else 709 goto fail; 710 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 711 spin_unlock_bh(&mpath->state_lock); 712 goto fail; 713 } 714 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 715 spin_unlock_bh(&mpath->state_lock); 716 --ttl; 717 flags = PREP_IE_FLAGS(prep_elem); 718 lifetime = PREP_IE_LIFETIME(prep_elem); 719 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 720 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 721 target_sn = PREP_IE_TARGET_SN(prep_elem); 722 orig_sn = PREP_IE_ORIG_SN(prep_elem); 723 724 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 725 target_addr, target_sn, next_hop, hopcount, 726 ttl, lifetime, metric, 0, sdata); 727 rcu_read_unlock(); 728 729 sdata->u.mesh.mshstats.fwded_unicast++; 730 sdata->u.mesh.mshstats.fwded_frames++; 731 return; 732 733 fail: 734 rcu_read_unlock(); 735 sdata->u.mesh.mshstats.dropped_frames_no_route++; 736 } 737 738 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 739 struct ieee80211_mgmt *mgmt, 740 const u8 *perr_elem) 741 { 742 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 743 struct mesh_path *mpath; 744 u8 ttl; 745 const u8 *ta, *target_addr; 746 u32 target_sn; 747 u16 target_rcode; 748 749 ta = mgmt->sa; 750 ttl = PERR_IE_TTL(perr_elem); 751 if (ttl <= 1) { 752 ifmsh->mshstats.dropped_frames_ttl++; 753 return; 754 } 755 ttl--; 756 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 757 target_sn = PERR_IE_TARGET_SN(perr_elem); 758 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 759 760 rcu_read_lock(); 761 mpath = mesh_path_lookup(sdata, target_addr); 762 if (mpath) { 763 struct sta_info *sta; 764 765 spin_lock_bh(&mpath->state_lock); 766 sta = next_hop_deref_protected(mpath); 767 if (mpath->flags & MESH_PATH_ACTIVE && 768 ether_addr_equal(ta, sta->sta.addr) && 769 !(mpath->flags & MESH_PATH_FIXED) && 770 (!(mpath->flags & MESH_PATH_SN_VALID) || 771 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 772 mpath->flags &= ~MESH_PATH_ACTIVE; 773 if (target_sn != 0) 774 mpath->sn = target_sn; 775 else 776 mpath->sn += 1; 777 spin_unlock_bh(&mpath->state_lock); 778 if (!ifmsh->mshcfg.dot11MeshForwarding) 779 goto endperr; 780 mesh_path_error_tx(sdata, ttl, target_addr, 781 target_sn, target_rcode, 782 broadcast_addr); 783 } else 784 spin_unlock_bh(&mpath->state_lock); 785 } 786 endperr: 787 rcu_read_unlock(); 788 } 789 790 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 791 struct ieee80211_mgmt *mgmt, 792 const struct ieee80211_rann_ie *rann) 793 { 794 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 795 struct ieee80211_local *local = sdata->local; 796 struct sta_info *sta; 797 struct mesh_path *mpath; 798 u8 ttl, flags, hopcount; 799 const u8 *orig_addr; 800 u32 orig_sn, metric, metric_txsta, interval; 801 bool root_is_gate; 802 803 ttl = rann->rann_ttl; 804 flags = rann->rann_flags; 805 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 806 orig_addr = rann->rann_addr; 807 orig_sn = le32_to_cpu(rann->rann_seq); 808 interval = le32_to_cpu(rann->rann_interval); 809 hopcount = rann->rann_hopcount; 810 hopcount++; 811 metric = le32_to_cpu(rann->rann_metric); 812 813 /* Ignore our own RANNs */ 814 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 815 return; 816 817 mhwmp_dbg(sdata, 818 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 819 orig_addr, mgmt->sa, root_is_gate); 820 821 rcu_read_lock(); 822 sta = sta_info_get(sdata, mgmt->sa); 823 if (!sta) { 824 rcu_read_unlock(); 825 return; 826 } 827 828 metric_txsta = airtime_link_metric_get(local, sta); 829 830 mpath = mesh_path_lookup(sdata, orig_addr); 831 if (!mpath) { 832 mpath = mesh_path_add(sdata, orig_addr); 833 if (IS_ERR(mpath)) { 834 rcu_read_unlock(); 835 sdata->u.mesh.mshstats.dropped_frames_no_route++; 836 return; 837 } 838 } 839 840 if (!(SN_LT(mpath->sn, orig_sn)) && 841 !(mpath->sn == orig_sn && metric < mpath->rann_metric)) { 842 rcu_read_unlock(); 843 return; 844 } 845 846 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 847 (time_after(jiffies, mpath->last_preq_to_root + 848 root_path_confirmation_jiffies(sdata)) || 849 time_before(jiffies, mpath->last_preq_to_root))) && 850 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 851 mhwmp_dbg(sdata, 852 "time to refresh root mpath %pM\n", 853 orig_addr); 854 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 855 mpath->last_preq_to_root = jiffies; 856 } 857 858 mpath->sn = orig_sn; 859 mpath->rann_metric = metric + metric_txsta; 860 mpath->is_root = true; 861 /* Recording RANNs sender address to send individually 862 * addressed PREQs destined for root mesh STA */ 863 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 864 865 if (root_is_gate) 866 mesh_path_add_gate(mpath); 867 868 if (ttl <= 1) { 869 ifmsh->mshstats.dropped_frames_ttl++; 870 rcu_read_unlock(); 871 return; 872 } 873 ttl--; 874 875 if (ifmsh->mshcfg.dot11MeshForwarding) { 876 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 877 orig_sn, 0, NULL, 0, broadcast_addr, 878 hopcount, ttl, interval, 879 metric + metric_txsta, 0, sdata); 880 } 881 882 rcu_read_unlock(); 883 } 884 885 886 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 887 struct ieee80211_mgmt *mgmt, size_t len) 888 { 889 struct ieee802_11_elems elems; 890 size_t baselen; 891 u32 path_metric; 892 struct sta_info *sta; 893 894 /* need action_code */ 895 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 896 return; 897 898 rcu_read_lock(); 899 sta = sta_info_get(sdata, mgmt->sa); 900 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 901 rcu_read_unlock(); 902 return; 903 } 904 rcu_read_unlock(); 905 906 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 907 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 908 len - baselen, false, &elems); 909 910 if (elems.preq) { 911 if (elems.preq_len != 37) 912 /* Right now we support just 1 destination and no AE */ 913 return; 914 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 915 MPATH_PREQ); 916 if (path_metric) 917 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 918 path_metric); 919 } 920 if (elems.prep) { 921 if (elems.prep_len != 31) 922 /* Right now we support no AE */ 923 return; 924 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 925 MPATH_PREP); 926 if (path_metric) 927 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 928 path_metric); 929 } 930 if (elems.perr) { 931 if (elems.perr_len != 15) 932 /* Right now we support only one destination per PERR */ 933 return; 934 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 935 } 936 if (elems.rann) 937 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 938 } 939 940 /** 941 * mesh_queue_preq - queue a PREQ to a given destination 942 * 943 * @mpath: mesh path to discover 944 * @flags: special attributes of the PREQ to be sent 945 * 946 * Locking: the function must be called from within a rcu read lock block. 947 * 948 */ 949 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 950 { 951 struct ieee80211_sub_if_data *sdata = mpath->sdata; 952 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 953 struct mesh_preq_queue *preq_node; 954 955 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 956 if (!preq_node) { 957 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 958 return; 959 } 960 961 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 962 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 963 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 964 kfree(preq_node); 965 if (printk_ratelimit()) 966 mhwmp_dbg(sdata, "PREQ node queue full\n"); 967 return; 968 } 969 970 spin_lock(&mpath->state_lock); 971 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 972 spin_unlock(&mpath->state_lock); 973 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 974 kfree(preq_node); 975 return; 976 } 977 978 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 979 preq_node->flags = flags; 980 981 mpath->flags |= MESH_PATH_REQ_QUEUED; 982 spin_unlock(&mpath->state_lock); 983 984 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 985 ++ifmsh->preq_queue_len; 986 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 987 988 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 989 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 990 991 else if (time_before(jiffies, ifmsh->last_preq)) { 992 /* avoid long wait if did not send preqs for a long time 993 * and jiffies wrapped around 994 */ 995 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 996 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 997 } else 998 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 999 min_preq_int_jiff(sdata)); 1000 } 1001 1002 /** 1003 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1004 * 1005 * @sdata: local mesh subif 1006 */ 1007 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1008 { 1009 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1010 struct mesh_preq_queue *preq_node; 1011 struct mesh_path *mpath; 1012 u8 ttl, target_flags = 0; 1013 const u8 *da; 1014 u32 lifetime; 1015 1016 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1017 if (!ifmsh->preq_queue_len || 1018 time_before(jiffies, ifmsh->last_preq + 1019 min_preq_int_jiff(sdata))) { 1020 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1021 return; 1022 } 1023 1024 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1025 struct mesh_preq_queue, list); 1026 list_del(&preq_node->list); 1027 --ifmsh->preq_queue_len; 1028 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1029 1030 rcu_read_lock(); 1031 mpath = mesh_path_lookup(sdata, preq_node->dst); 1032 if (!mpath) 1033 goto enddiscovery; 1034 1035 spin_lock_bh(&mpath->state_lock); 1036 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1037 spin_unlock_bh(&mpath->state_lock); 1038 goto enddiscovery; 1039 } 1040 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1041 if (preq_node->flags & PREQ_Q_F_START) { 1042 if (mpath->flags & MESH_PATH_RESOLVING) { 1043 spin_unlock_bh(&mpath->state_lock); 1044 goto enddiscovery; 1045 } else { 1046 mpath->flags &= ~MESH_PATH_RESOLVED; 1047 mpath->flags |= MESH_PATH_RESOLVING; 1048 mpath->discovery_retries = 0; 1049 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1050 } 1051 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1052 mpath->flags & MESH_PATH_RESOLVED) { 1053 mpath->flags &= ~MESH_PATH_RESOLVING; 1054 spin_unlock_bh(&mpath->state_lock); 1055 goto enddiscovery; 1056 } 1057 1058 ifmsh->last_preq = jiffies; 1059 1060 if (time_after(jiffies, ifmsh->last_sn_update + 1061 net_traversal_jiffies(sdata)) || 1062 time_before(jiffies, ifmsh->last_sn_update)) { 1063 ++ifmsh->sn; 1064 sdata->u.mesh.last_sn_update = jiffies; 1065 } 1066 lifetime = default_lifetime(sdata); 1067 ttl = sdata->u.mesh.mshcfg.element_ttl; 1068 if (ttl == 0) { 1069 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1070 spin_unlock_bh(&mpath->state_lock); 1071 goto enddiscovery; 1072 } 1073 1074 if (preq_node->flags & PREQ_Q_F_REFRESH) 1075 target_flags |= IEEE80211_PREQ_TO_FLAG; 1076 else 1077 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1078 1079 spin_unlock_bh(&mpath->state_lock); 1080 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1081 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1082 target_flags, mpath->dst, mpath->sn, da, 0, 1083 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1084 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1085 1086 enddiscovery: 1087 rcu_read_unlock(); 1088 kfree(preq_node); 1089 } 1090 1091 /** 1092 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1093 * 1094 * @skb: 802.11 frame to be sent 1095 * @sdata: network subif the frame will be sent through 1096 * 1097 * Lookup next hop for given skb and start path discovery if no 1098 * forwarding information is found. 1099 * 1100 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1101 * skb is freeed here if no mpath could be allocated. 1102 */ 1103 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1104 struct sk_buff *skb) 1105 { 1106 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1107 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1108 struct mesh_path *mpath; 1109 struct sk_buff *skb_to_free = NULL; 1110 u8 *target_addr = hdr->addr3; 1111 int err = 0; 1112 1113 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1114 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1115 return 0; 1116 1117 rcu_read_lock(); 1118 err = mesh_nexthop_lookup(sdata, skb); 1119 if (!err) 1120 goto endlookup; 1121 1122 /* no nexthop found, start resolving */ 1123 mpath = mesh_path_lookup(sdata, target_addr); 1124 if (!mpath) { 1125 mpath = mesh_path_add(sdata, target_addr); 1126 if (IS_ERR(mpath)) { 1127 mesh_path_discard_frame(sdata, skb); 1128 err = PTR_ERR(mpath); 1129 goto endlookup; 1130 } 1131 } 1132 1133 if (!(mpath->flags & MESH_PATH_RESOLVING)) 1134 mesh_queue_preq(mpath, PREQ_Q_F_START); 1135 1136 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1137 skb_to_free = skb_dequeue(&mpath->frame_queue); 1138 1139 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 1140 ieee80211_set_qos_hdr(sdata, skb); 1141 skb_queue_tail(&mpath->frame_queue, skb); 1142 err = -ENOENT; 1143 if (skb_to_free) 1144 mesh_path_discard_frame(sdata, skb_to_free); 1145 1146 endlookup: 1147 rcu_read_unlock(); 1148 return err; 1149 } 1150 1151 /** 1152 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1153 * this function is considered "using" the associated mpath, so preempt a path 1154 * refresh if this mpath expires soon. 1155 * 1156 * @skb: 802.11 frame to be sent 1157 * @sdata: network subif the frame will be sent through 1158 * 1159 * Returns: 0 if the next hop was found. Nonzero otherwise. 1160 */ 1161 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1162 struct sk_buff *skb) 1163 { 1164 struct mesh_path *mpath; 1165 struct sta_info *next_hop; 1166 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1167 u8 *target_addr = hdr->addr3; 1168 int err = -ENOENT; 1169 1170 rcu_read_lock(); 1171 mpath = mesh_path_lookup(sdata, target_addr); 1172 1173 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1174 goto endlookup; 1175 1176 if (time_after(jiffies, 1177 mpath->exp_time - 1178 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1179 ether_addr_equal(sdata->vif.addr, hdr->addr4) && 1180 !(mpath->flags & MESH_PATH_RESOLVING) && 1181 !(mpath->flags & MESH_PATH_FIXED)) 1182 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1183 1184 next_hop = rcu_dereference(mpath->next_hop); 1185 if (next_hop) { 1186 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1187 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1188 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1189 err = 0; 1190 } 1191 1192 endlookup: 1193 rcu_read_unlock(); 1194 return err; 1195 } 1196 1197 void mesh_path_timer(unsigned long data) 1198 { 1199 struct mesh_path *mpath = (void *) data; 1200 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1201 int ret; 1202 1203 if (sdata->local->quiescing) 1204 return; 1205 1206 spin_lock_bh(&mpath->state_lock); 1207 if (mpath->flags & MESH_PATH_RESOLVED || 1208 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1209 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1210 spin_unlock_bh(&mpath->state_lock); 1211 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1212 ++mpath->discovery_retries; 1213 mpath->discovery_timeout *= 2; 1214 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1215 spin_unlock_bh(&mpath->state_lock); 1216 mesh_queue_preq(mpath, 0); 1217 } else { 1218 mpath->flags &= ~(MESH_PATH_RESOLVING | 1219 MESH_PATH_RESOLVED | 1220 MESH_PATH_REQ_QUEUED); 1221 mpath->exp_time = jiffies; 1222 spin_unlock_bh(&mpath->state_lock); 1223 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1224 ret = mesh_path_send_to_gates(mpath); 1225 if (ret) 1226 mhwmp_dbg(sdata, "no gate was reachable\n"); 1227 } else 1228 mesh_path_flush_pending(mpath); 1229 } 1230 } 1231 1232 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1233 { 1234 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1235 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1236 u8 flags, target_flags = 0; 1237 1238 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1239 ? RANN_FLAG_IS_GATE : 0; 1240 1241 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1242 case IEEE80211_PROACTIVE_RANN: 1243 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1244 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1245 0, ifmsh->mshcfg.element_ttl, 1246 interval, 0, 0, sdata); 1247 break; 1248 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1249 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1250 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1251 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1252 target_flags |= IEEE80211_PREQ_TO_FLAG | 1253 IEEE80211_PREQ_USN_FLAG; 1254 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1255 ++ifmsh->sn, target_flags, 1256 (u8 *) broadcast_addr, 0, broadcast_addr, 1257 0, ifmsh->mshcfg.element_ttl, interval, 1258 0, ifmsh->preq_id++, sdata); 1259 break; 1260 default: 1261 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1262 return; 1263 } 1264 } 1265