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 struct rate_info rinfo; 304 305 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 306 307 /* moving average, scaled to 100. 308 * feed failure as 100 and success as 0 309 */ 310 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); 311 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 312 LINK_FAIL_THRESH) 313 mesh_plink_broken(sta); 314 315 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo); 316 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg, 317 cfg80211_calculate_bitrate(&rinfo)); 318 } 319 320 static u32 airtime_link_metric_get(struct ieee80211_local *local, 321 struct sta_info *sta) 322 { 323 /* This should be adjusted for each device */ 324 int device_constant = 1 << ARITH_SHIFT; 325 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 326 int s_unit = 1 << ARITH_SHIFT; 327 int rate, err; 328 u32 tx_time, estimated_retx; 329 u64 result; 330 unsigned long fail_avg = 331 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 332 333 /* Try to get rate based on HW/SW RC algorithm. 334 * Rate is returned in units of Kbps, correct this 335 * to comply with airtime calculation units 336 * Round up in case we get rate < 100Kbps 337 */ 338 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 339 340 if (rate) { 341 err = 0; 342 } else { 343 if (fail_avg > LINK_FAIL_THRESH) 344 return MAX_METRIC; 345 346 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg); 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 u8 hopcount; 393 394 rcu_read_lock(); 395 sta = sta_info_get(sdata, mgmt->sa); 396 if (!sta) { 397 rcu_read_unlock(); 398 return 0; 399 } 400 401 last_hop_metric = airtime_link_metric_get(local, sta); 402 /* Update and check originator routing info */ 403 fresh_info = true; 404 405 switch (action) { 406 case MPATH_PREQ: 407 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 408 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 409 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 410 orig_metric = PREQ_IE_METRIC(hwmp_ie); 411 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1; 412 break; 413 case MPATH_PREP: 414 /* Originator here refers to the MP that was the target in the 415 * Path Request. We divert from the nomenclature in the draft 416 * so that we can easily use a single function to gather path 417 * information from both PREQ and PREP frames. 418 */ 419 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 420 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 421 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 422 orig_metric = PREP_IE_METRIC(hwmp_ie); 423 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1; 424 break; 425 default: 426 rcu_read_unlock(); 427 return 0; 428 } 429 new_metric = orig_metric + last_hop_metric; 430 if (new_metric < orig_metric) 431 new_metric = MAX_METRIC; 432 exp_time = TU_TO_EXP_TIME(orig_lifetime); 433 434 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 435 /* This MP is the originator, we are not interested in this 436 * frame, except for updating transmitter's path info. 437 */ 438 process = false; 439 fresh_info = false; 440 } else { 441 mpath = mesh_path_lookup(sdata, orig_addr); 442 if (mpath) { 443 spin_lock_bh(&mpath->state_lock); 444 if (mpath->flags & MESH_PATH_FIXED) 445 fresh_info = false; 446 else if ((mpath->flags & MESH_PATH_ACTIVE) && 447 (mpath->flags & MESH_PATH_SN_VALID)) { 448 if (SN_GT(mpath->sn, orig_sn) || 449 (mpath->sn == orig_sn && 450 (rcu_access_pointer(mpath->next_hop) != 451 sta ? 452 mult_frac(new_metric, 10, 9) : 453 new_metric) >= mpath->metric)) { 454 process = false; 455 fresh_info = false; 456 } 457 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 458 bool have_sn, newer_sn, bounced; 459 460 have_sn = mpath->flags & MESH_PATH_SN_VALID; 461 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 462 bounced = have_sn && 463 (SN_DELTA(orig_sn, mpath->sn) > 464 MAX_SANE_SN_DELTA); 465 466 if (!have_sn || newer_sn) { 467 /* if SN is newer than what we had 468 * then we can take it */; 469 } else if (bounced) { 470 /* if SN is way different than what 471 * we had then assume the other side 472 * rebooted or restarted */; 473 } else { 474 process = false; 475 fresh_info = false; 476 } 477 } 478 } else { 479 mpath = mesh_path_add(sdata, orig_addr); 480 if (IS_ERR(mpath)) { 481 rcu_read_unlock(); 482 return 0; 483 } 484 spin_lock_bh(&mpath->state_lock); 485 } 486 487 if (fresh_info) { 488 if (rcu_access_pointer(mpath->next_hop) != sta) 489 mpath->path_change_count++; 490 mesh_path_assign_nexthop(mpath, sta); 491 mpath->flags |= MESH_PATH_SN_VALID; 492 mpath->metric = new_metric; 493 mpath->sn = orig_sn; 494 mpath->exp_time = time_after(mpath->exp_time, exp_time) 495 ? mpath->exp_time : exp_time; 496 mpath->hop_count = hopcount; 497 mesh_path_activate(mpath); 498 spin_unlock_bh(&mpath->state_lock); 499 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 500 /* init it at a low value - 0 start is tricky */ 501 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 502 mesh_path_tx_pending(mpath); 503 /* draft says preq_id should be saved to, but there does 504 * not seem to be any use for it, skipping by now 505 */ 506 } else 507 spin_unlock_bh(&mpath->state_lock); 508 } 509 510 /* Update and check transmitter routing info */ 511 ta = mgmt->sa; 512 if (ether_addr_equal(orig_addr, ta)) 513 fresh_info = false; 514 else { 515 fresh_info = true; 516 517 mpath = mesh_path_lookup(sdata, ta); 518 if (mpath) { 519 spin_lock_bh(&mpath->state_lock); 520 if ((mpath->flags & MESH_PATH_FIXED) || 521 ((mpath->flags & MESH_PATH_ACTIVE) && 522 ((rcu_access_pointer(mpath->next_hop) != sta ? 523 mult_frac(last_hop_metric, 10, 9) : 524 last_hop_metric) > mpath->metric))) 525 fresh_info = false; 526 } else { 527 mpath = mesh_path_add(sdata, ta); 528 if (IS_ERR(mpath)) { 529 rcu_read_unlock(); 530 return 0; 531 } 532 spin_lock_bh(&mpath->state_lock); 533 } 534 535 if (fresh_info) { 536 if (rcu_access_pointer(mpath->next_hop) != sta) 537 mpath->path_change_count++; 538 mesh_path_assign_nexthop(mpath, sta); 539 mpath->metric = last_hop_metric; 540 mpath->exp_time = time_after(mpath->exp_time, exp_time) 541 ? mpath->exp_time : exp_time; 542 mpath->hop_count = 1; 543 mesh_path_activate(mpath); 544 spin_unlock_bh(&mpath->state_lock); 545 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 546 /* init it at a low value - 0 start is tricky */ 547 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 548 mesh_path_tx_pending(mpath); 549 } else 550 spin_unlock_bh(&mpath->state_lock); 551 } 552 553 rcu_read_unlock(); 554 555 return process ? new_metric : 0; 556 } 557 558 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 559 struct ieee80211_mgmt *mgmt, 560 const u8 *preq_elem, u32 orig_metric) 561 { 562 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 563 struct mesh_path *mpath = NULL; 564 const u8 *target_addr, *orig_addr; 565 const u8 *da; 566 u8 target_flags, ttl, flags; 567 u32 orig_sn, target_sn, lifetime, target_metric = 0; 568 bool reply = false; 569 bool forward = true; 570 bool root_is_gate; 571 572 /* Update target SN, if present */ 573 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 574 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 575 target_sn = PREQ_IE_TARGET_SN(preq_elem); 576 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 577 target_flags = PREQ_IE_TARGET_F(preq_elem); 578 /* Proactive PREQ gate announcements */ 579 flags = PREQ_IE_FLAGS(preq_elem); 580 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 581 582 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 583 584 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 585 mhwmp_dbg(sdata, "PREQ is for us\n"); 586 forward = false; 587 reply = true; 588 target_metric = 0; 589 590 if (SN_GT(target_sn, ifmsh->sn)) 591 ifmsh->sn = target_sn; 592 593 if (time_after(jiffies, ifmsh->last_sn_update + 594 net_traversal_jiffies(sdata)) || 595 time_before(jiffies, ifmsh->last_sn_update)) { 596 ++ifmsh->sn; 597 ifmsh->last_sn_update = jiffies; 598 } 599 target_sn = ifmsh->sn; 600 } else if (is_broadcast_ether_addr(target_addr) && 601 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 602 rcu_read_lock(); 603 mpath = mesh_path_lookup(sdata, orig_addr); 604 if (mpath) { 605 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 606 reply = true; 607 target_addr = sdata->vif.addr; 608 target_sn = ++ifmsh->sn; 609 target_metric = 0; 610 ifmsh->last_sn_update = jiffies; 611 } 612 if (root_is_gate) 613 mesh_path_add_gate(mpath); 614 } 615 rcu_read_unlock(); 616 } else { 617 rcu_read_lock(); 618 mpath = mesh_path_lookup(sdata, target_addr); 619 if (mpath) { 620 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 621 SN_LT(mpath->sn, target_sn)) { 622 mpath->sn = target_sn; 623 mpath->flags |= MESH_PATH_SN_VALID; 624 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 625 (mpath->flags & MESH_PATH_ACTIVE)) { 626 reply = true; 627 target_metric = mpath->metric; 628 target_sn = mpath->sn; 629 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 630 target_flags |= IEEE80211_PREQ_TO_FLAG; 631 } 632 } 633 rcu_read_unlock(); 634 } 635 636 if (reply) { 637 lifetime = PREQ_IE_LIFETIME(preq_elem); 638 ttl = ifmsh->mshcfg.element_ttl; 639 if (ttl != 0) { 640 mhwmp_dbg(sdata, "replying to the PREQ\n"); 641 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 642 orig_sn, 0, target_addr, 643 target_sn, mgmt->sa, 0, ttl, 644 lifetime, target_metric, 0, 645 sdata); 646 } else { 647 ifmsh->mshstats.dropped_frames_ttl++; 648 } 649 } 650 651 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 652 u32 preq_id; 653 u8 hopcount; 654 655 ttl = PREQ_IE_TTL(preq_elem); 656 lifetime = PREQ_IE_LIFETIME(preq_elem); 657 if (ttl <= 1) { 658 ifmsh->mshstats.dropped_frames_ttl++; 659 return; 660 } 661 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 662 --ttl; 663 preq_id = PREQ_IE_PREQ_ID(preq_elem); 664 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 665 da = (mpath && mpath->is_root) ? 666 mpath->rann_snd_addr : broadcast_addr; 667 668 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 669 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 670 target_sn = PREQ_IE_TARGET_SN(preq_elem); 671 } 672 673 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 674 orig_sn, target_flags, target_addr, 675 target_sn, da, hopcount, ttl, lifetime, 676 orig_metric, preq_id, sdata); 677 if (!is_multicast_ether_addr(da)) 678 ifmsh->mshstats.fwded_unicast++; 679 else 680 ifmsh->mshstats.fwded_mcast++; 681 ifmsh->mshstats.fwded_frames++; 682 } 683 } 684 685 686 static inline struct sta_info * 687 next_hop_deref_protected(struct mesh_path *mpath) 688 { 689 return rcu_dereference_protected(mpath->next_hop, 690 lockdep_is_held(&mpath->state_lock)); 691 } 692 693 694 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 695 struct ieee80211_mgmt *mgmt, 696 const u8 *prep_elem, u32 metric) 697 { 698 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 699 struct mesh_path *mpath; 700 const u8 *target_addr, *orig_addr; 701 u8 ttl, hopcount, flags; 702 u8 next_hop[ETH_ALEN]; 703 u32 target_sn, orig_sn, lifetime; 704 705 mhwmp_dbg(sdata, "received PREP from %pM\n", 706 PREP_IE_TARGET_ADDR(prep_elem)); 707 708 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 709 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 710 /* destination, no forwarding required */ 711 return; 712 713 if (!ifmsh->mshcfg.dot11MeshForwarding) 714 return; 715 716 ttl = PREP_IE_TTL(prep_elem); 717 if (ttl <= 1) { 718 sdata->u.mesh.mshstats.dropped_frames_ttl++; 719 return; 720 } 721 722 rcu_read_lock(); 723 mpath = mesh_path_lookup(sdata, orig_addr); 724 if (mpath) 725 spin_lock_bh(&mpath->state_lock); 726 else 727 goto fail; 728 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 729 spin_unlock_bh(&mpath->state_lock); 730 goto fail; 731 } 732 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 733 spin_unlock_bh(&mpath->state_lock); 734 --ttl; 735 flags = PREP_IE_FLAGS(prep_elem); 736 lifetime = PREP_IE_LIFETIME(prep_elem); 737 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 738 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 739 target_sn = PREP_IE_TARGET_SN(prep_elem); 740 orig_sn = PREP_IE_ORIG_SN(prep_elem); 741 742 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 743 target_addr, target_sn, next_hop, hopcount, 744 ttl, lifetime, metric, 0, sdata); 745 rcu_read_unlock(); 746 747 sdata->u.mesh.mshstats.fwded_unicast++; 748 sdata->u.mesh.mshstats.fwded_frames++; 749 return; 750 751 fail: 752 rcu_read_unlock(); 753 sdata->u.mesh.mshstats.dropped_frames_no_route++; 754 } 755 756 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 757 struct ieee80211_mgmt *mgmt, 758 const u8 *perr_elem) 759 { 760 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 761 struct mesh_path *mpath; 762 u8 ttl; 763 const u8 *ta, *target_addr; 764 u32 target_sn; 765 u16 target_rcode; 766 767 ta = mgmt->sa; 768 ttl = PERR_IE_TTL(perr_elem); 769 if (ttl <= 1) { 770 ifmsh->mshstats.dropped_frames_ttl++; 771 return; 772 } 773 ttl--; 774 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 775 target_sn = PERR_IE_TARGET_SN(perr_elem); 776 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 777 778 rcu_read_lock(); 779 mpath = mesh_path_lookup(sdata, target_addr); 780 if (mpath) { 781 struct sta_info *sta; 782 783 spin_lock_bh(&mpath->state_lock); 784 sta = next_hop_deref_protected(mpath); 785 if (mpath->flags & MESH_PATH_ACTIVE && 786 ether_addr_equal(ta, sta->sta.addr) && 787 !(mpath->flags & MESH_PATH_FIXED) && 788 (!(mpath->flags & MESH_PATH_SN_VALID) || 789 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 790 mpath->flags &= ~MESH_PATH_ACTIVE; 791 if (target_sn != 0) 792 mpath->sn = target_sn; 793 else 794 mpath->sn += 1; 795 spin_unlock_bh(&mpath->state_lock); 796 if (!ifmsh->mshcfg.dot11MeshForwarding) 797 goto endperr; 798 mesh_path_error_tx(sdata, ttl, target_addr, 799 target_sn, target_rcode, 800 broadcast_addr); 801 } else 802 spin_unlock_bh(&mpath->state_lock); 803 } 804 endperr: 805 rcu_read_unlock(); 806 } 807 808 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 809 struct ieee80211_mgmt *mgmt, 810 const struct ieee80211_rann_ie *rann) 811 { 812 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 813 struct ieee80211_local *local = sdata->local; 814 struct sta_info *sta; 815 struct mesh_path *mpath; 816 u8 ttl, flags, hopcount; 817 const u8 *orig_addr; 818 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; 819 bool root_is_gate; 820 821 ttl = rann->rann_ttl; 822 flags = rann->rann_flags; 823 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 824 orig_addr = rann->rann_addr; 825 orig_sn = le32_to_cpu(rann->rann_seq); 826 interval = le32_to_cpu(rann->rann_interval); 827 hopcount = rann->rann_hopcount; 828 hopcount++; 829 orig_metric = le32_to_cpu(rann->rann_metric); 830 831 /* Ignore our own RANNs */ 832 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 833 return; 834 835 mhwmp_dbg(sdata, 836 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 837 orig_addr, mgmt->sa, root_is_gate); 838 839 rcu_read_lock(); 840 sta = sta_info_get(sdata, mgmt->sa); 841 if (!sta) { 842 rcu_read_unlock(); 843 return; 844 } 845 846 last_hop_metric = airtime_link_metric_get(local, sta); 847 new_metric = orig_metric + last_hop_metric; 848 if (new_metric < orig_metric) 849 new_metric = MAX_METRIC; 850 851 mpath = mesh_path_lookup(sdata, orig_addr); 852 if (!mpath) { 853 mpath = mesh_path_add(sdata, orig_addr); 854 if (IS_ERR(mpath)) { 855 rcu_read_unlock(); 856 sdata->u.mesh.mshstats.dropped_frames_no_route++; 857 return; 858 } 859 } 860 861 if (!(SN_LT(mpath->sn, orig_sn)) && 862 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { 863 rcu_read_unlock(); 864 return; 865 } 866 867 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 868 (time_after(jiffies, mpath->last_preq_to_root + 869 root_path_confirmation_jiffies(sdata)) || 870 time_before(jiffies, mpath->last_preq_to_root))) && 871 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 872 mhwmp_dbg(sdata, 873 "time to refresh root mpath %pM\n", 874 orig_addr); 875 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 876 mpath->last_preq_to_root = jiffies; 877 } 878 879 mpath->sn = orig_sn; 880 mpath->rann_metric = new_metric; 881 mpath->is_root = true; 882 /* Recording RANNs sender address to send individually 883 * addressed PREQs destined for root mesh STA */ 884 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 885 886 if (root_is_gate) 887 mesh_path_add_gate(mpath); 888 889 if (ttl <= 1) { 890 ifmsh->mshstats.dropped_frames_ttl++; 891 rcu_read_unlock(); 892 return; 893 } 894 ttl--; 895 896 if (ifmsh->mshcfg.dot11MeshForwarding) { 897 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 898 orig_sn, 0, NULL, 0, broadcast_addr, 899 hopcount, ttl, interval, 900 new_metric, 0, sdata); 901 } 902 903 rcu_read_unlock(); 904 } 905 906 907 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 908 struct ieee80211_mgmt *mgmt, size_t len) 909 { 910 struct ieee802_11_elems elems; 911 size_t baselen; 912 u32 path_metric; 913 struct sta_info *sta; 914 915 /* need action_code */ 916 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 917 return; 918 919 rcu_read_lock(); 920 sta = sta_info_get(sdata, mgmt->sa); 921 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 922 rcu_read_unlock(); 923 return; 924 } 925 rcu_read_unlock(); 926 927 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 928 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 929 len - baselen, false, &elems); 930 931 if (elems.preq) { 932 if (elems.preq_len != 37) 933 /* Right now we support just 1 destination and no AE */ 934 return; 935 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 936 MPATH_PREQ); 937 if (path_metric) 938 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 939 path_metric); 940 } 941 if (elems.prep) { 942 if (elems.prep_len != 31) 943 /* Right now we support no AE */ 944 return; 945 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 946 MPATH_PREP); 947 if (path_metric) 948 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 949 path_metric); 950 } 951 if (elems.perr) { 952 if (elems.perr_len != 15) 953 /* Right now we support only one destination per PERR */ 954 return; 955 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 956 } 957 if (elems.rann) 958 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 959 } 960 961 /** 962 * mesh_queue_preq - queue a PREQ to a given destination 963 * 964 * @mpath: mesh path to discover 965 * @flags: special attributes of the PREQ to be sent 966 * 967 * Locking: the function must be called from within a rcu read lock block. 968 * 969 */ 970 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 971 { 972 struct ieee80211_sub_if_data *sdata = mpath->sdata; 973 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 974 struct mesh_preq_queue *preq_node; 975 976 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 977 if (!preq_node) { 978 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 979 return; 980 } 981 982 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 983 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 984 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 985 kfree(preq_node); 986 if (printk_ratelimit()) 987 mhwmp_dbg(sdata, "PREQ node queue full\n"); 988 return; 989 } 990 991 spin_lock(&mpath->state_lock); 992 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 993 spin_unlock(&mpath->state_lock); 994 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 995 kfree(preq_node); 996 return; 997 } 998 999 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 1000 preq_node->flags = flags; 1001 1002 mpath->flags |= MESH_PATH_REQ_QUEUED; 1003 spin_unlock(&mpath->state_lock); 1004 1005 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 1006 ++ifmsh->preq_queue_len; 1007 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1008 1009 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 1010 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1011 1012 else if (time_before(jiffies, ifmsh->last_preq)) { 1013 /* avoid long wait if did not send preqs for a long time 1014 * and jiffies wrapped around 1015 */ 1016 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 1017 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1018 } else 1019 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 1020 min_preq_int_jiff(sdata)); 1021 } 1022 1023 /** 1024 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1025 * 1026 * @sdata: local mesh subif 1027 */ 1028 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1029 { 1030 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1031 struct mesh_preq_queue *preq_node; 1032 struct mesh_path *mpath; 1033 u8 ttl, target_flags = 0; 1034 const u8 *da; 1035 u32 lifetime; 1036 1037 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1038 if (!ifmsh->preq_queue_len || 1039 time_before(jiffies, ifmsh->last_preq + 1040 min_preq_int_jiff(sdata))) { 1041 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1042 return; 1043 } 1044 1045 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1046 struct mesh_preq_queue, list); 1047 list_del(&preq_node->list); 1048 --ifmsh->preq_queue_len; 1049 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1050 1051 rcu_read_lock(); 1052 mpath = mesh_path_lookup(sdata, preq_node->dst); 1053 if (!mpath) 1054 goto enddiscovery; 1055 1056 spin_lock_bh(&mpath->state_lock); 1057 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1058 spin_unlock_bh(&mpath->state_lock); 1059 goto enddiscovery; 1060 } 1061 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1062 if (preq_node->flags & PREQ_Q_F_START) { 1063 if (mpath->flags & MESH_PATH_RESOLVING) { 1064 spin_unlock_bh(&mpath->state_lock); 1065 goto enddiscovery; 1066 } else { 1067 mpath->flags &= ~MESH_PATH_RESOLVED; 1068 mpath->flags |= MESH_PATH_RESOLVING; 1069 mpath->discovery_retries = 0; 1070 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1071 } 1072 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1073 mpath->flags & MESH_PATH_RESOLVED) { 1074 mpath->flags &= ~MESH_PATH_RESOLVING; 1075 spin_unlock_bh(&mpath->state_lock); 1076 goto enddiscovery; 1077 } 1078 1079 ifmsh->last_preq = jiffies; 1080 1081 if (time_after(jiffies, ifmsh->last_sn_update + 1082 net_traversal_jiffies(sdata)) || 1083 time_before(jiffies, ifmsh->last_sn_update)) { 1084 ++ifmsh->sn; 1085 sdata->u.mesh.last_sn_update = jiffies; 1086 } 1087 lifetime = default_lifetime(sdata); 1088 ttl = sdata->u.mesh.mshcfg.element_ttl; 1089 if (ttl == 0) { 1090 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1091 spin_unlock_bh(&mpath->state_lock); 1092 goto enddiscovery; 1093 } 1094 1095 if (preq_node->flags & PREQ_Q_F_REFRESH) 1096 target_flags |= IEEE80211_PREQ_TO_FLAG; 1097 else 1098 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1099 1100 spin_unlock_bh(&mpath->state_lock); 1101 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1102 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1103 target_flags, mpath->dst, mpath->sn, da, 0, 1104 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1105 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1106 1107 enddiscovery: 1108 rcu_read_unlock(); 1109 kfree(preq_node); 1110 } 1111 1112 /** 1113 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1114 * 1115 * @skb: 802.11 frame to be sent 1116 * @sdata: network subif the frame will be sent through 1117 * 1118 * Lookup next hop for given skb and start path discovery if no 1119 * forwarding information is found. 1120 * 1121 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1122 * skb is freeed here if no mpath could be allocated. 1123 */ 1124 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1125 struct sk_buff *skb) 1126 { 1127 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1128 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1129 struct mesh_path *mpath; 1130 struct sk_buff *skb_to_free = NULL; 1131 u8 *target_addr = hdr->addr3; 1132 int err = 0; 1133 1134 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1135 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1136 return 0; 1137 1138 rcu_read_lock(); 1139 err = mesh_nexthop_lookup(sdata, skb); 1140 if (!err) 1141 goto endlookup; 1142 1143 /* no nexthop found, start resolving */ 1144 mpath = mesh_path_lookup(sdata, target_addr); 1145 if (!mpath) { 1146 mpath = mesh_path_add(sdata, target_addr); 1147 if (IS_ERR(mpath)) { 1148 mesh_path_discard_frame(sdata, skb); 1149 err = PTR_ERR(mpath); 1150 goto endlookup; 1151 } 1152 } 1153 1154 if (!(mpath->flags & MESH_PATH_RESOLVING)) 1155 mesh_queue_preq(mpath, PREQ_Q_F_START); 1156 1157 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1158 skb_to_free = skb_dequeue(&mpath->frame_queue); 1159 1160 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 1161 ieee80211_set_qos_hdr(sdata, skb); 1162 skb_queue_tail(&mpath->frame_queue, skb); 1163 err = -ENOENT; 1164 if (skb_to_free) 1165 mesh_path_discard_frame(sdata, skb_to_free); 1166 1167 endlookup: 1168 rcu_read_unlock(); 1169 return err; 1170 } 1171 1172 /** 1173 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1174 * this function is considered "using" the associated mpath, so preempt a path 1175 * refresh if this mpath expires soon. 1176 * 1177 * @skb: 802.11 frame to be sent 1178 * @sdata: network subif the frame will be sent through 1179 * 1180 * Returns: 0 if the next hop was found. Nonzero otherwise. 1181 */ 1182 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1183 struct sk_buff *skb) 1184 { 1185 struct mesh_path *mpath; 1186 struct sta_info *next_hop; 1187 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1188 u8 *target_addr = hdr->addr3; 1189 int err = -ENOENT; 1190 1191 rcu_read_lock(); 1192 mpath = mesh_path_lookup(sdata, target_addr); 1193 1194 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1195 goto endlookup; 1196 1197 if (time_after(jiffies, 1198 mpath->exp_time - 1199 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1200 ether_addr_equal(sdata->vif.addr, hdr->addr4) && 1201 !(mpath->flags & MESH_PATH_RESOLVING) && 1202 !(mpath->flags & MESH_PATH_FIXED)) 1203 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1204 1205 next_hop = rcu_dereference(mpath->next_hop); 1206 if (next_hop) { 1207 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1208 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1209 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1210 err = 0; 1211 } 1212 1213 endlookup: 1214 rcu_read_unlock(); 1215 return err; 1216 } 1217 1218 void mesh_path_timer(struct timer_list *t) 1219 { 1220 struct mesh_path *mpath = from_timer(mpath, t, timer); 1221 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1222 int ret; 1223 1224 if (sdata->local->quiescing) 1225 return; 1226 1227 spin_lock_bh(&mpath->state_lock); 1228 if (mpath->flags & MESH_PATH_RESOLVED || 1229 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1230 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1231 spin_unlock_bh(&mpath->state_lock); 1232 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1233 ++mpath->discovery_retries; 1234 mpath->discovery_timeout *= 2; 1235 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1236 spin_unlock_bh(&mpath->state_lock); 1237 mesh_queue_preq(mpath, 0); 1238 } else { 1239 mpath->flags &= ~(MESH_PATH_RESOLVING | 1240 MESH_PATH_RESOLVED | 1241 MESH_PATH_REQ_QUEUED); 1242 mpath->exp_time = jiffies; 1243 spin_unlock_bh(&mpath->state_lock); 1244 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1245 ret = mesh_path_send_to_gates(mpath); 1246 if (ret) 1247 mhwmp_dbg(sdata, "no gate was reachable\n"); 1248 } else 1249 mesh_path_flush_pending(mpath); 1250 } 1251 } 1252 1253 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1254 { 1255 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1256 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1257 u8 flags, target_flags = 0; 1258 1259 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1260 ? RANN_FLAG_IS_GATE : 0; 1261 1262 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1263 case IEEE80211_PROACTIVE_RANN: 1264 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1265 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1266 0, ifmsh->mshcfg.element_ttl, 1267 interval, 0, 0, sdata); 1268 break; 1269 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1270 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1271 /* fall through */ 1272 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1273 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1274 target_flags |= IEEE80211_PREQ_TO_FLAG | 1275 IEEE80211_PREQ_USN_FLAG; 1276 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1277 ++ifmsh->sn, target_flags, 1278 (u8 *) broadcast_addr, 0, broadcast_addr, 1279 0, ifmsh->mshcfg.element_ttl, interval, 1280 0, ifmsh->preq_id++, sdata); 1281 break; 1282 default: 1283 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1284 return; 1285 } 1286 } 1287