1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019 Intel Corporation 5 * Author: Luis Carlos Cobo <luisca@cozybit.com> 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/etherdevice.h> 10 #include <asm/unaligned.h> 11 #include "wme.h" 12 #include "mesh.h" 13 14 #define TEST_FRAME_LEN 8192 15 #define MAX_METRIC 0xffffffff 16 #define ARITH_SHIFT 8 17 #define LINK_FAIL_THRESH 95 18 19 #define MAX_PREQ_QUEUE_LEN 64 20 21 static void mesh_queue_preq(struct mesh_path *, u8); 22 23 static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae) 24 { 25 if (ae) 26 offset += 6; 27 return get_unaligned_le32(preq_elem + offset); 28 } 29 30 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae) 31 { 32 if (ae) 33 offset += 6; 34 return get_unaligned_le16(preq_elem + offset); 35 } 36 37 /* HWMP IE processing macros */ 38 #define AE_F (1<<6) 39 #define AE_F_SET(x) (*x & AE_F) 40 #define PREQ_IE_FLAGS(x) (*(x)) 41 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 42 #define PREQ_IE_TTL(x) (*(x + 2)) 43 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 44 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 45 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0) 46 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)) 47 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)) 48 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 49 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 50 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)) 51 52 53 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 54 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 55 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 56 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 57 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x)) 58 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)) 59 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)) 60 #define PREP_IE_TARGET_ADDR(x) (x + 3) 61 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 62 63 #define PERR_IE_TTL(x) (*(x)) 64 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 65 #define PERR_IE_TARGET_ADDR(x) (x + 3) 66 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 67 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) 68 69 #define MSEC_TO_TU(x) (x*1000/1024) 70 #define SN_GT(x, y) ((s32)(y - x) < 0) 71 #define SN_LT(x, y) ((s32)(x - y) < 0) 72 #define MAX_SANE_SN_DELTA 32 73 74 static inline u32 SN_DELTA(u32 x, u32 y) 75 { 76 return x >= y ? x - y : y - x; 77 } 78 79 #define net_traversal_jiffies(s) \ 80 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 81 #define default_lifetime(s) \ 82 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 83 #define min_preq_int_jiff(s) \ 84 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 85 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 86 #define disc_timeout_jiff(s) \ 87 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 88 #define root_path_confirmation_jiffies(s) \ 89 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval) 90 91 enum mpath_frame_type { 92 MPATH_PREQ = 0, 93 MPATH_PREP, 94 MPATH_PERR, 95 MPATH_RANN 96 }; 97 98 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 99 100 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 101 const u8 *orig_addr, u32 orig_sn, 102 u8 target_flags, const u8 *target, 103 u32 target_sn, const u8 *da, 104 u8 hop_count, u8 ttl, 105 u32 lifetime, u32 metric, u32 preq_id, 106 struct ieee80211_sub_if_data *sdata) 107 { 108 struct ieee80211_local *local = sdata->local; 109 struct sk_buff *skb; 110 struct ieee80211_mgmt *mgmt; 111 u8 *pos, ie_len; 112 int hdr_len = offsetofend(struct ieee80211_mgmt, 113 u.action.u.mesh_action); 114 115 skb = dev_alloc_skb(local->tx_headroom + 116 hdr_len + 117 2 + 37); /* max HWMP IE */ 118 if (!skb) 119 return -1; 120 skb_reserve(skb, local->tx_headroom); 121 mgmt = skb_put_zero(skb, hdr_len); 122 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 123 IEEE80211_STYPE_ACTION); 124 125 memcpy(mgmt->da, da, ETH_ALEN); 126 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 127 /* BSSID == SA */ 128 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 129 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 130 mgmt->u.action.u.mesh_action.action_code = 131 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 132 133 switch (action) { 134 case MPATH_PREQ: 135 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target); 136 ie_len = 37; 137 pos = skb_put(skb, 2 + ie_len); 138 *pos++ = WLAN_EID_PREQ; 139 break; 140 case MPATH_PREP: 141 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr); 142 ie_len = 31; 143 pos = skb_put(skb, 2 + ie_len); 144 *pos++ = WLAN_EID_PREP; 145 break; 146 case MPATH_RANN: 147 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr); 148 ie_len = sizeof(struct ieee80211_rann_ie); 149 pos = skb_put(skb, 2 + ie_len); 150 *pos++ = WLAN_EID_RANN; 151 break; 152 default: 153 kfree_skb(skb); 154 return -ENOTSUPP; 155 } 156 *pos++ = ie_len; 157 *pos++ = flags; 158 *pos++ = hop_count; 159 *pos++ = ttl; 160 if (action == MPATH_PREP) { 161 memcpy(pos, target, ETH_ALEN); 162 pos += ETH_ALEN; 163 put_unaligned_le32(target_sn, pos); 164 pos += 4; 165 } else { 166 if (action == MPATH_PREQ) { 167 put_unaligned_le32(preq_id, pos); 168 pos += 4; 169 } 170 memcpy(pos, orig_addr, ETH_ALEN); 171 pos += ETH_ALEN; 172 put_unaligned_le32(orig_sn, pos); 173 pos += 4; 174 } 175 put_unaligned_le32(lifetime, pos); /* interval for RANN */ 176 pos += 4; 177 put_unaligned_le32(metric, pos); 178 pos += 4; 179 if (action == MPATH_PREQ) { 180 *pos++ = 1; /* destination count */ 181 *pos++ = target_flags; 182 memcpy(pos, target, ETH_ALEN); 183 pos += ETH_ALEN; 184 put_unaligned_le32(target_sn, pos); 185 pos += 4; 186 } else if (action == MPATH_PREP) { 187 memcpy(pos, orig_addr, ETH_ALEN); 188 pos += ETH_ALEN; 189 put_unaligned_le32(orig_sn, pos); 190 pos += 4; 191 } 192 193 ieee80211_tx_skb(sdata, skb); 194 return 0; 195 } 196 197 198 /* Headroom is not adjusted. Caller should ensure that skb has sufficient 199 * headroom in case the frame is encrypted. */ 200 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, 201 struct sk_buff *skb) 202 { 203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 204 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 205 206 skb_reset_mac_header(skb); 207 skb_reset_network_header(skb); 208 skb_reset_transport_header(skb); 209 210 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ 211 skb_set_queue_mapping(skb, IEEE80211_AC_VO); 212 skb->priority = 7; 213 214 info->control.vif = &sdata->vif; 215 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 216 ieee80211_set_qos_hdr(sdata, skb); 217 ieee80211_mps_set_frame_flags(sdata, NULL, hdr); 218 } 219 220 /** 221 * mesh_path_error_tx - Sends a PERR mesh management frame 222 * 223 * @ttl: allowed remaining hops 224 * @target: broken destination 225 * @target_sn: SN of the broken destination 226 * @target_rcode: reason code for this PERR 227 * @ra: node this frame is addressed to 228 * @sdata: local mesh subif 229 * 230 * Note: This function may be called with driver locks taken that the driver 231 * also acquires in the TX path. To avoid a deadlock we don't transmit the 232 * frame directly but add it to the pending queue instead. 233 */ 234 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata, 235 u8 ttl, const u8 *target, u32 target_sn, 236 u16 target_rcode, const u8 *ra) 237 { 238 struct ieee80211_local *local = sdata->local; 239 struct sk_buff *skb; 240 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 241 struct ieee80211_mgmt *mgmt; 242 u8 *pos, ie_len; 243 int hdr_len = offsetofend(struct ieee80211_mgmt, 244 u.action.u.mesh_action); 245 246 if (time_before(jiffies, ifmsh->next_perr)) 247 return -EAGAIN; 248 249 skb = dev_alloc_skb(local->tx_headroom + 250 sdata->encrypt_headroom + 251 IEEE80211_ENCRYPT_TAILROOM + 252 hdr_len + 253 2 + 15 /* PERR IE */); 254 if (!skb) 255 return -1; 256 skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom); 257 mgmt = skb_put_zero(skb, hdr_len); 258 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 259 IEEE80211_STYPE_ACTION); 260 261 memcpy(mgmt->da, ra, ETH_ALEN); 262 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 263 /* BSSID == SA */ 264 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 265 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 266 mgmt->u.action.u.mesh_action.action_code = 267 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 268 ie_len = 15; 269 pos = skb_put(skb, 2 + ie_len); 270 *pos++ = WLAN_EID_PERR; 271 *pos++ = ie_len; 272 /* ttl */ 273 *pos++ = ttl; 274 /* number of destinations */ 275 *pos++ = 1; 276 /* Flags field has AE bit only as defined in 277 * sec 8.4.2.117 IEEE802.11-2012 278 */ 279 *pos = 0; 280 pos++; 281 memcpy(pos, target, ETH_ALEN); 282 pos += ETH_ALEN; 283 put_unaligned_le32(target_sn, pos); 284 pos += 4; 285 put_unaligned_le16(target_rcode, pos); 286 287 /* see note in function header */ 288 prepare_frame_for_deferred_tx(sdata, skb); 289 ifmsh->next_perr = TU_TO_EXP_TIME( 290 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval); 291 ieee80211_add_pending_skb(local, skb); 292 return 0; 293 } 294 295 void ieee80211s_update_metric(struct ieee80211_local *local, 296 struct sta_info *sta, 297 struct ieee80211_tx_status *st) 298 { 299 struct ieee80211_tx_info *txinfo = st->info; 300 int failed; 301 struct rate_info rinfo; 302 303 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 304 305 /* moving average, scaled to 100. 306 * feed failure as 100 and success as 0 307 */ 308 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); 309 if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 310 LINK_FAIL_THRESH) 311 mesh_plink_broken(sta); 312 313 sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo); 314 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg, 315 cfg80211_calculate_bitrate(&rinfo)); 316 } 317 318 u32 airtime_link_metric_get(struct ieee80211_local *local, 319 struct sta_info *sta) 320 { 321 /* This should be adjusted for each device */ 322 int device_constant = 1 << ARITH_SHIFT; 323 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 324 int s_unit = 1 << ARITH_SHIFT; 325 int rate, err; 326 u32 tx_time, estimated_retx; 327 u64 result; 328 unsigned long fail_avg = 329 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 330 331 /* Try to get rate based on HW/SW RC algorithm. 332 * Rate is returned in units of Kbps, correct this 333 * to comply with airtime calculation units 334 * Round up in case we get rate < 100Kbps 335 */ 336 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 337 338 if (rate) { 339 err = 0; 340 } else { 341 if (fail_avg > LINK_FAIL_THRESH) 342 return MAX_METRIC; 343 344 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg); 345 if (WARN_ON(!rate)) 346 return MAX_METRIC; 347 348 err = (fail_avg << ARITH_SHIFT) / 100; 349 } 350 351 /* bitrate is in units of 100 Kbps, while we need rate in units of 352 * 1Mbps. This will be corrected on tx_time computation. 353 */ 354 tx_time = (device_constant + 10 * test_frame_len / rate); 355 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 356 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT); 357 return (u32)result; 358 } 359 360 /** 361 * hwmp_route_info_get - Update routing info to originator and transmitter 362 * 363 * @sdata: local mesh subif 364 * @mgmt: mesh management frame 365 * @hwmp_ie: hwmp information element (PREP or PREQ) 366 * @action: type of hwmp ie 367 * 368 * This function updates the path routing information to the originator and the 369 * transmitter of a HWMP PREQ or PREP frame. 370 * 371 * Returns: metric to frame originator or 0 if the frame should not be further 372 * processed 373 * 374 * Notes: this function is the only place (besides user-provided info) where 375 * path routing information is updated. 376 */ 377 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 378 struct ieee80211_mgmt *mgmt, 379 const u8 *hwmp_ie, enum mpath_frame_type action) 380 { 381 struct ieee80211_local *local = sdata->local; 382 struct mesh_path *mpath; 383 struct sta_info *sta; 384 bool fresh_info; 385 const u8 *orig_addr, *ta; 386 u32 orig_sn, orig_metric; 387 unsigned long orig_lifetime, exp_time; 388 u32 last_hop_metric, new_metric; 389 bool process = true; 390 u8 hopcount; 391 392 rcu_read_lock(); 393 sta = sta_info_get(sdata, mgmt->sa); 394 if (!sta) { 395 rcu_read_unlock(); 396 return 0; 397 } 398 399 last_hop_metric = airtime_link_metric_get(local, sta); 400 /* Update and check originator routing info */ 401 fresh_info = true; 402 403 switch (action) { 404 case MPATH_PREQ: 405 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 406 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 407 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 408 orig_metric = PREQ_IE_METRIC(hwmp_ie); 409 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1; 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 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1; 422 break; 423 default: 424 rcu_read_unlock(); 425 return 0; 426 } 427 new_metric = orig_metric + last_hop_metric; 428 if (new_metric < orig_metric) 429 new_metric = MAX_METRIC; 430 exp_time = TU_TO_EXP_TIME(orig_lifetime); 431 432 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 433 /* This MP is the originator, we are not interested in this 434 * frame, except for updating transmitter's path info. 435 */ 436 process = false; 437 fresh_info = false; 438 } else { 439 mpath = mesh_path_lookup(sdata, orig_addr); 440 if (mpath) { 441 spin_lock_bh(&mpath->state_lock); 442 if (mpath->flags & MESH_PATH_FIXED) 443 fresh_info = false; 444 else if ((mpath->flags & MESH_PATH_ACTIVE) && 445 (mpath->flags & MESH_PATH_SN_VALID)) { 446 if (SN_GT(mpath->sn, orig_sn) || 447 (mpath->sn == orig_sn && 448 (rcu_access_pointer(mpath->next_hop) != 449 sta ? 450 mult_frac(new_metric, 10, 9) : 451 new_metric) >= mpath->metric)) { 452 process = false; 453 fresh_info = false; 454 } 455 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 456 bool have_sn, newer_sn, bounced; 457 458 have_sn = mpath->flags & MESH_PATH_SN_VALID; 459 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 460 bounced = have_sn && 461 (SN_DELTA(orig_sn, mpath->sn) > 462 MAX_SANE_SN_DELTA); 463 464 if (!have_sn || newer_sn) { 465 /* if SN is newer than what we had 466 * then we can take it */; 467 } else if (bounced) { 468 /* if SN is way different than what 469 * we had then assume the other side 470 * rebooted or restarted */; 471 } else { 472 process = false; 473 fresh_info = false; 474 } 475 } 476 } else { 477 mpath = mesh_path_add(sdata, orig_addr); 478 if (IS_ERR(mpath)) { 479 rcu_read_unlock(); 480 return 0; 481 } 482 spin_lock_bh(&mpath->state_lock); 483 } 484 485 if (fresh_info) { 486 if (rcu_access_pointer(mpath->next_hop) != sta) 487 mpath->path_change_count++; 488 mesh_path_assign_nexthop(mpath, sta); 489 mpath->flags |= MESH_PATH_SN_VALID; 490 mpath->metric = new_metric; 491 mpath->sn = orig_sn; 492 mpath->exp_time = time_after(mpath->exp_time, exp_time) 493 ? mpath->exp_time : exp_time; 494 mpath->hop_count = hopcount; 495 mesh_path_activate(mpath); 496 spin_unlock_bh(&mpath->state_lock); 497 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 498 /* init it at a low value - 0 start is tricky */ 499 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 500 mesh_path_tx_pending(mpath); 501 /* draft says preq_id should be saved to, but there does 502 * not seem to be any use for it, skipping by now 503 */ 504 } else 505 spin_unlock_bh(&mpath->state_lock); 506 } 507 508 /* Update and check transmitter routing info */ 509 ta = mgmt->sa; 510 if (ether_addr_equal(orig_addr, ta)) 511 fresh_info = false; 512 else { 513 fresh_info = true; 514 515 mpath = mesh_path_lookup(sdata, ta); 516 if (mpath) { 517 spin_lock_bh(&mpath->state_lock); 518 if ((mpath->flags & MESH_PATH_FIXED) || 519 ((mpath->flags & MESH_PATH_ACTIVE) && 520 ((rcu_access_pointer(mpath->next_hop) != sta ? 521 mult_frac(last_hop_metric, 10, 9) : 522 last_hop_metric) > mpath->metric))) 523 fresh_info = false; 524 } else { 525 mpath = mesh_path_add(sdata, ta); 526 if (IS_ERR(mpath)) { 527 rcu_read_unlock(); 528 return 0; 529 } 530 spin_lock_bh(&mpath->state_lock); 531 } 532 533 if (fresh_info) { 534 if (rcu_access_pointer(mpath->next_hop) != sta) 535 mpath->path_change_count++; 536 mesh_path_assign_nexthop(mpath, sta); 537 mpath->metric = last_hop_metric; 538 mpath->exp_time = time_after(mpath->exp_time, exp_time) 539 ? mpath->exp_time : exp_time; 540 mpath->hop_count = 1; 541 mesh_path_activate(mpath); 542 spin_unlock_bh(&mpath->state_lock); 543 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 544 /* init it at a low value - 0 start is tricky */ 545 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 546 mesh_path_tx_pending(mpath); 547 } else 548 spin_unlock_bh(&mpath->state_lock); 549 } 550 551 rcu_read_unlock(); 552 553 return process ? new_metric : 0; 554 } 555 556 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 557 struct ieee80211_mgmt *mgmt, 558 const u8 *preq_elem, u32 orig_metric) 559 { 560 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 561 struct mesh_path *mpath = NULL; 562 const u8 *target_addr, *orig_addr; 563 const u8 *da; 564 u8 target_flags, ttl, flags; 565 u32 orig_sn, target_sn, lifetime, target_metric = 0; 566 bool reply = false; 567 bool forward = true; 568 bool root_is_gate; 569 570 /* Update target SN, if present */ 571 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 572 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 573 target_sn = PREQ_IE_TARGET_SN(preq_elem); 574 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 575 target_flags = PREQ_IE_TARGET_F(preq_elem); 576 /* Proactive PREQ gate announcements */ 577 flags = PREQ_IE_FLAGS(preq_elem); 578 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 579 580 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 581 582 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 583 mhwmp_dbg(sdata, "PREQ is for us\n"); 584 forward = false; 585 reply = true; 586 target_metric = 0; 587 588 if (SN_GT(target_sn, ifmsh->sn)) 589 ifmsh->sn = target_sn; 590 591 if (time_after(jiffies, ifmsh->last_sn_update + 592 net_traversal_jiffies(sdata)) || 593 time_before(jiffies, ifmsh->last_sn_update)) { 594 ++ifmsh->sn; 595 ifmsh->last_sn_update = jiffies; 596 } 597 target_sn = ifmsh->sn; 598 } else if (is_broadcast_ether_addr(target_addr) && 599 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 600 rcu_read_lock(); 601 mpath = mesh_path_lookup(sdata, orig_addr); 602 if (mpath) { 603 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 604 reply = true; 605 target_addr = sdata->vif.addr; 606 target_sn = ++ifmsh->sn; 607 target_metric = 0; 608 ifmsh->last_sn_update = jiffies; 609 } 610 if (root_is_gate) 611 mesh_path_add_gate(mpath); 612 } 613 rcu_read_unlock(); 614 } else { 615 rcu_read_lock(); 616 mpath = mesh_path_lookup(sdata, target_addr); 617 if (mpath) { 618 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 619 SN_LT(mpath->sn, target_sn)) { 620 mpath->sn = target_sn; 621 mpath->flags |= MESH_PATH_SN_VALID; 622 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 623 (mpath->flags & MESH_PATH_ACTIVE)) { 624 reply = true; 625 target_metric = mpath->metric; 626 target_sn = mpath->sn; 627 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 628 target_flags |= IEEE80211_PREQ_TO_FLAG; 629 } 630 } 631 rcu_read_unlock(); 632 } 633 634 if (reply) { 635 lifetime = PREQ_IE_LIFETIME(preq_elem); 636 ttl = ifmsh->mshcfg.element_ttl; 637 if (ttl != 0) { 638 mhwmp_dbg(sdata, "replying to the PREQ\n"); 639 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 640 orig_sn, 0, target_addr, 641 target_sn, mgmt->sa, 0, ttl, 642 lifetime, target_metric, 0, 643 sdata); 644 } else { 645 ifmsh->mshstats.dropped_frames_ttl++; 646 } 647 } 648 649 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 650 u32 preq_id; 651 u8 hopcount; 652 653 ttl = PREQ_IE_TTL(preq_elem); 654 lifetime = PREQ_IE_LIFETIME(preq_elem); 655 if (ttl <= 1) { 656 ifmsh->mshstats.dropped_frames_ttl++; 657 return; 658 } 659 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 660 --ttl; 661 preq_id = PREQ_IE_PREQ_ID(preq_elem); 662 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 663 da = (mpath && mpath->is_root) ? 664 mpath->rann_snd_addr : broadcast_addr; 665 666 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 667 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 668 target_sn = PREQ_IE_TARGET_SN(preq_elem); 669 } 670 671 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 672 orig_sn, target_flags, target_addr, 673 target_sn, da, hopcount, ttl, lifetime, 674 orig_metric, preq_id, sdata); 675 if (!is_multicast_ether_addr(da)) 676 ifmsh->mshstats.fwded_unicast++; 677 else 678 ifmsh->mshstats.fwded_mcast++; 679 ifmsh->mshstats.fwded_frames++; 680 } 681 } 682 683 684 static inline struct sta_info * 685 next_hop_deref_protected(struct mesh_path *mpath) 686 { 687 return rcu_dereference_protected(mpath->next_hop, 688 lockdep_is_held(&mpath->state_lock)); 689 } 690 691 692 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 693 struct ieee80211_mgmt *mgmt, 694 const u8 *prep_elem, u32 metric) 695 { 696 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 697 struct mesh_path *mpath; 698 const u8 *target_addr, *orig_addr; 699 u8 ttl, hopcount, flags; 700 u8 next_hop[ETH_ALEN]; 701 u32 target_sn, orig_sn, lifetime; 702 703 mhwmp_dbg(sdata, "received PREP from %pM\n", 704 PREP_IE_TARGET_ADDR(prep_elem)); 705 706 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 707 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 708 /* destination, no forwarding required */ 709 return; 710 711 if (!ifmsh->mshcfg.dot11MeshForwarding) 712 return; 713 714 ttl = PREP_IE_TTL(prep_elem); 715 if (ttl <= 1) { 716 sdata->u.mesh.mshstats.dropped_frames_ttl++; 717 return; 718 } 719 720 rcu_read_lock(); 721 mpath = mesh_path_lookup(sdata, orig_addr); 722 if (mpath) 723 spin_lock_bh(&mpath->state_lock); 724 else 725 goto fail; 726 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 727 spin_unlock_bh(&mpath->state_lock); 728 goto fail; 729 } 730 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 731 spin_unlock_bh(&mpath->state_lock); 732 --ttl; 733 flags = PREP_IE_FLAGS(prep_elem); 734 lifetime = PREP_IE_LIFETIME(prep_elem); 735 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 736 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 737 target_sn = PREP_IE_TARGET_SN(prep_elem); 738 orig_sn = PREP_IE_ORIG_SN(prep_elem); 739 740 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 741 target_addr, target_sn, next_hop, hopcount, 742 ttl, lifetime, metric, 0, sdata); 743 rcu_read_unlock(); 744 745 sdata->u.mesh.mshstats.fwded_unicast++; 746 sdata->u.mesh.mshstats.fwded_frames++; 747 return; 748 749 fail: 750 rcu_read_unlock(); 751 sdata->u.mesh.mshstats.dropped_frames_no_route++; 752 } 753 754 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 755 struct ieee80211_mgmt *mgmt, 756 const u8 *perr_elem) 757 { 758 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 759 struct mesh_path *mpath; 760 u8 ttl; 761 const u8 *ta, *target_addr; 762 u32 target_sn; 763 u16 target_rcode; 764 765 ta = mgmt->sa; 766 ttl = PERR_IE_TTL(perr_elem); 767 if (ttl <= 1) { 768 ifmsh->mshstats.dropped_frames_ttl++; 769 return; 770 } 771 ttl--; 772 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 773 target_sn = PERR_IE_TARGET_SN(perr_elem); 774 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 775 776 rcu_read_lock(); 777 mpath = mesh_path_lookup(sdata, target_addr); 778 if (mpath) { 779 struct sta_info *sta; 780 781 spin_lock_bh(&mpath->state_lock); 782 sta = next_hop_deref_protected(mpath); 783 if (mpath->flags & MESH_PATH_ACTIVE && 784 ether_addr_equal(ta, sta->sta.addr) && 785 !(mpath->flags & MESH_PATH_FIXED) && 786 (!(mpath->flags & MESH_PATH_SN_VALID) || 787 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 788 mpath->flags &= ~MESH_PATH_ACTIVE; 789 if (target_sn != 0) 790 mpath->sn = target_sn; 791 else 792 mpath->sn += 1; 793 spin_unlock_bh(&mpath->state_lock); 794 if (!ifmsh->mshcfg.dot11MeshForwarding) 795 goto endperr; 796 mesh_path_error_tx(sdata, ttl, target_addr, 797 target_sn, target_rcode, 798 broadcast_addr); 799 } else 800 spin_unlock_bh(&mpath->state_lock); 801 } 802 endperr: 803 rcu_read_unlock(); 804 } 805 806 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 807 struct ieee80211_mgmt *mgmt, 808 const struct ieee80211_rann_ie *rann) 809 { 810 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 811 struct ieee80211_local *local = sdata->local; 812 struct sta_info *sta; 813 struct mesh_path *mpath; 814 u8 ttl, flags, hopcount; 815 const u8 *orig_addr; 816 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; 817 bool root_is_gate; 818 819 ttl = rann->rann_ttl; 820 flags = rann->rann_flags; 821 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 822 orig_addr = rann->rann_addr; 823 orig_sn = le32_to_cpu(rann->rann_seq); 824 interval = le32_to_cpu(rann->rann_interval); 825 hopcount = rann->rann_hopcount; 826 hopcount++; 827 orig_metric = le32_to_cpu(rann->rann_metric); 828 829 /* Ignore our own RANNs */ 830 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 831 return; 832 833 mhwmp_dbg(sdata, 834 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 835 orig_addr, mgmt->sa, root_is_gate); 836 837 rcu_read_lock(); 838 sta = sta_info_get(sdata, mgmt->sa); 839 if (!sta) { 840 rcu_read_unlock(); 841 return; 842 } 843 844 last_hop_metric = airtime_link_metric_get(local, sta); 845 new_metric = orig_metric + last_hop_metric; 846 if (new_metric < orig_metric) 847 new_metric = MAX_METRIC; 848 849 mpath = mesh_path_lookup(sdata, orig_addr); 850 if (!mpath) { 851 mpath = mesh_path_add(sdata, orig_addr); 852 if (IS_ERR(mpath)) { 853 rcu_read_unlock(); 854 sdata->u.mesh.mshstats.dropped_frames_no_route++; 855 return; 856 } 857 } 858 859 if (!(SN_LT(mpath->sn, orig_sn)) && 860 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { 861 rcu_read_unlock(); 862 return; 863 } 864 865 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 866 (time_after(jiffies, mpath->last_preq_to_root + 867 root_path_confirmation_jiffies(sdata)) || 868 time_before(jiffies, mpath->last_preq_to_root))) && 869 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 870 mhwmp_dbg(sdata, 871 "time to refresh root mpath %pM\n", 872 orig_addr); 873 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 874 mpath->last_preq_to_root = jiffies; 875 } 876 877 mpath->sn = orig_sn; 878 mpath->rann_metric = new_metric; 879 mpath->is_root = true; 880 /* Recording RANNs sender address to send individually 881 * addressed PREQs destined for root mesh STA */ 882 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 883 884 if (root_is_gate) 885 mesh_path_add_gate(mpath); 886 887 if (ttl <= 1) { 888 ifmsh->mshstats.dropped_frames_ttl++; 889 rcu_read_unlock(); 890 return; 891 } 892 ttl--; 893 894 if (ifmsh->mshcfg.dot11MeshForwarding) { 895 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 896 orig_sn, 0, NULL, 0, broadcast_addr, 897 hopcount, ttl, interval, 898 new_metric, 0, sdata); 899 } 900 901 rcu_read_unlock(); 902 } 903 904 905 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 906 struct ieee80211_mgmt *mgmt, size_t len) 907 { 908 struct ieee802_11_elems elems; 909 size_t baselen; 910 u32 path_metric; 911 struct sta_info *sta; 912 913 /* need action_code */ 914 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 915 return; 916 917 rcu_read_lock(); 918 sta = sta_info_get(sdata, mgmt->sa); 919 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 920 rcu_read_unlock(); 921 return; 922 } 923 rcu_read_unlock(); 924 925 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 926 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 927 len - baselen, false, &elems, mgmt->bssid, NULL); 928 929 if (elems.preq) { 930 if (elems.preq_len != 37) 931 /* Right now we support just 1 destination and no AE */ 932 return; 933 path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 934 MPATH_PREQ); 935 if (path_metric) 936 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 937 path_metric); 938 } 939 if (elems.prep) { 940 if (elems.prep_len != 31) 941 /* Right now we support no AE */ 942 return; 943 path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 944 MPATH_PREP); 945 if (path_metric) 946 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 947 path_metric); 948 } 949 if (elems.perr) { 950 if (elems.perr_len != 15) 951 /* Right now we support only one destination per PERR */ 952 return; 953 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 954 } 955 if (elems.rann) 956 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 957 } 958 959 /** 960 * mesh_queue_preq - queue a PREQ to a given destination 961 * 962 * @mpath: mesh path to discover 963 * @flags: special attributes of the PREQ to be sent 964 * 965 * Locking: the function must be called from within a rcu read lock block. 966 * 967 */ 968 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 969 { 970 struct ieee80211_sub_if_data *sdata = mpath->sdata; 971 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 972 struct mesh_preq_queue *preq_node; 973 974 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 975 if (!preq_node) { 976 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 977 return; 978 } 979 980 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 981 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 982 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 983 kfree(preq_node); 984 if (printk_ratelimit()) 985 mhwmp_dbg(sdata, "PREQ node queue full\n"); 986 return; 987 } 988 989 spin_lock(&mpath->state_lock); 990 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 991 spin_unlock(&mpath->state_lock); 992 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 993 kfree(preq_node); 994 return; 995 } 996 997 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 998 preq_node->flags = flags; 999 1000 mpath->flags |= MESH_PATH_REQ_QUEUED; 1001 spin_unlock(&mpath->state_lock); 1002 1003 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 1004 ++ifmsh->preq_queue_len; 1005 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1006 1007 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 1008 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1009 1010 else if (time_before(jiffies, ifmsh->last_preq)) { 1011 /* avoid long wait if did not send preqs for a long time 1012 * and jiffies wrapped around 1013 */ 1014 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 1015 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1016 } else 1017 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 1018 min_preq_int_jiff(sdata)); 1019 } 1020 1021 /** 1022 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1023 * 1024 * @sdata: local mesh subif 1025 */ 1026 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1027 { 1028 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1029 struct mesh_preq_queue *preq_node; 1030 struct mesh_path *mpath; 1031 u8 ttl, target_flags = 0; 1032 const u8 *da; 1033 u32 lifetime; 1034 1035 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1036 if (!ifmsh->preq_queue_len || 1037 time_before(jiffies, ifmsh->last_preq + 1038 min_preq_int_jiff(sdata))) { 1039 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1040 return; 1041 } 1042 1043 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1044 struct mesh_preq_queue, list); 1045 list_del(&preq_node->list); 1046 --ifmsh->preq_queue_len; 1047 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1048 1049 rcu_read_lock(); 1050 mpath = mesh_path_lookup(sdata, preq_node->dst); 1051 if (!mpath) 1052 goto enddiscovery; 1053 1054 spin_lock_bh(&mpath->state_lock); 1055 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1056 spin_unlock_bh(&mpath->state_lock); 1057 goto enddiscovery; 1058 } 1059 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1060 if (preq_node->flags & PREQ_Q_F_START) { 1061 if (mpath->flags & MESH_PATH_RESOLVING) { 1062 spin_unlock_bh(&mpath->state_lock); 1063 goto enddiscovery; 1064 } else { 1065 mpath->flags &= ~MESH_PATH_RESOLVED; 1066 mpath->flags |= MESH_PATH_RESOLVING; 1067 mpath->discovery_retries = 0; 1068 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1069 } 1070 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1071 mpath->flags & MESH_PATH_RESOLVED) { 1072 mpath->flags &= ~MESH_PATH_RESOLVING; 1073 spin_unlock_bh(&mpath->state_lock); 1074 goto enddiscovery; 1075 } 1076 1077 ifmsh->last_preq = jiffies; 1078 1079 if (time_after(jiffies, ifmsh->last_sn_update + 1080 net_traversal_jiffies(sdata)) || 1081 time_before(jiffies, ifmsh->last_sn_update)) { 1082 ++ifmsh->sn; 1083 sdata->u.mesh.last_sn_update = jiffies; 1084 } 1085 lifetime = default_lifetime(sdata); 1086 ttl = sdata->u.mesh.mshcfg.element_ttl; 1087 if (ttl == 0) { 1088 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1089 spin_unlock_bh(&mpath->state_lock); 1090 goto enddiscovery; 1091 } 1092 1093 if (preq_node->flags & PREQ_Q_F_REFRESH) 1094 target_flags |= IEEE80211_PREQ_TO_FLAG; 1095 else 1096 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1097 1098 spin_unlock_bh(&mpath->state_lock); 1099 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1100 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1101 target_flags, mpath->dst, mpath->sn, da, 0, 1102 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1103 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1104 1105 enddiscovery: 1106 rcu_read_unlock(); 1107 kfree(preq_node); 1108 } 1109 1110 /** 1111 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1112 * 1113 * @skb: 802.11 frame to be sent 1114 * @sdata: network subif the frame will be sent through 1115 * 1116 * Lookup next hop for given skb and start path discovery if no 1117 * forwarding information is found. 1118 * 1119 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1120 * skb is freeed here if no mpath could be allocated. 1121 */ 1122 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1123 struct sk_buff *skb) 1124 { 1125 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1126 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1127 struct mesh_path *mpath; 1128 struct sk_buff *skb_to_free = NULL; 1129 u8 *target_addr = hdr->addr3; 1130 1131 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1132 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1133 return 0; 1134 1135 /* Allow injected packets to bypass mesh routing */ 1136 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP) 1137 return 0; 1138 1139 if (!mesh_nexthop_lookup(sdata, skb)) 1140 return 0; 1141 1142 /* no nexthop found, start resolving */ 1143 mpath = mesh_path_lookup(sdata, target_addr); 1144 if (!mpath) { 1145 mpath = mesh_path_add(sdata, target_addr); 1146 if (IS_ERR(mpath)) { 1147 mesh_path_discard_frame(sdata, skb); 1148 return PTR_ERR(mpath); 1149 } 1150 } 1151 1152 if (!(mpath->flags & MESH_PATH_RESOLVING)) 1153 mesh_queue_preq(mpath, PREQ_Q_F_START); 1154 1155 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1156 skb_to_free = skb_dequeue(&mpath->frame_queue); 1157 1158 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 1159 ieee80211_set_qos_hdr(sdata, skb); 1160 skb_queue_tail(&mpath->frame_queue, skb); 1161 if (skb_to_free) 1162 mesh_path_discard_frame(sdata, skb_to_free); 1163 1164 return -ENOENT; 1165 } 1166 1167 /** 1168 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1169 * this function is considered "using" the associated mpath, so preempt a path 1170 * refresh if this mpath expires soon. 1171 * 1172 * @skb: 802.11 frame to be sent 1173 * @sdata: network subif the frame will be sent through 1174 * 1175 * Returns: 0 if the next hop was found. Nonzero otherwise. 1176 */ 1177 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1178 struct sk_buff *skb) 1179 { 1180 struct mesh_path *mpath; 1181 struct sta_info *next_hop; 1182 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1183 u8 *target_addr = hdr->addr3; 1184 1185 mpath = mesh_path_lookup(sdata, target_addr); 1186 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1187 return -ENOENT; 1188 1189 if (time_after(jiffies, 1190 mpath->exp_time - 1191 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1192 ether_addr_equal(sdata->vif.addr, hdr->addr4) && 1193 !(mpath->flags & MESH_PATH_RESOLVING) && 1194 !(mpath->flags & MESH_PATH_FIXED)) 1195 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1196 1197 next_hop = rcu_dereference(mpath->next_hop); 1198 if (next_hop) { 1199 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1200 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1201 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1202 return 0; 1203 } 1204 1205 return -ENOENT; 1206 } 1207 1208 void mesh_path_timer(struct timer_list *t) 1209 { 1210 struct mesh_path *mpath = from_timer(mpath, t, timer); 1211 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1212 int ret; 1213 1214 if (sdata->local->quiescing) 1215 return; 1216 1217 spin_lock_bh(&mpath->state_lock); 1218 if (mpath->flags & MESH_PATH_RESOLVED || 1219 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1220 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1221 spin_unlock_bh(&mpath->state_lock); 1222 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1223 ++mpath->discovery_retries; 1224 mpath->discovery_timeout *= 2; 1225 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1226 spin_unlock_bh(&mpath->state_lock); 1227 mesh_queue_preq(mpath, 0); 1228 } else { 1229 mpath->flags &= ~(MESH_PATH_RESOLVING | 1230 MESH_PATH_RESOLVED | 1231 MESH_PATH_REQ_QUEUED); 1232 mpath->exp_time = jiffies; 1233 spin_unlock_bh(&mpath->state_lock); 1234 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1235 ret = mesh_path_send_to_gates(mpath); 1236 if (ret) 1237 mhwmp_dbg(sdata, "no gate was reachable\n"); 1238 } else 1239 mesh_path_flush_pending(mpath); 1240 } 1241 } 1242 1243 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1244 { 1245 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1246 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1247 u8 flags, target_flags = 0; 1248 1249 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1250 ? RANN_FLAG_IS_GATE : 0; 1251 1252 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1253 case IEEE80211_PROACTIVE_RANN: 1254 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1255 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1256 0, ifmsh->mshcfg.element_ttl, 1257 interval, 0, 0, sdata); 1258 break; 1259 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1260 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1261 /* fall through */ 1262 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1263 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1264 target_flags |= IEEE80211_PREQ_TO_FLAG | 1265 IEEE80211_PREQ_USN_FLAG; 1266 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1267 ++ifmsh->sn, target_flags, 1268 (u8 *) broadcast_addr, 0, broadcast_addr, 1269 0, ifmsh->mshcfg.element_ttl, interval, 1270 0, ifmsh->preq_id++, sdata); 1271 break; 1272 default: 1273 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1274 return; 1275 } 1276 } 1277