1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021-2023 Intel Corporation 5 * Author: Luis Carlos Cobo <luisca@cozybit.com> 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/etherdevice.h> 10 #include <linux/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 u32_field_get(const u8 * preq_elem,int offset,bool ae)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 u16_field_get(const u8 * preq_elem,int offset,bool ae)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 SN_DELTA(u32 x,u32 y)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 mesh_path_sel_frame_tx(enum mpath_frame_type action,u8 flags,const u8 * orig_addr,u32 orig_sn,u8 target_flags,const u8 * target,u32 target_sn,const u8 * da,u8 hop_count,u8 ttl,u32 lifetime,u32 metric,u32 preq_id,struct ieee80211_sub_if_data * sdata)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 -EOPNOTSUPP; 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. */ prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)200 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, 201 struct sk_buff *skb) 202 { 203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 204 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 205 206 skb_reset_mac_header(skb); 207 skb_reset_network_header(skb); 208 skb_reset_transport_header(skb); 209 210 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ 211 skb_set_queue_mapping(skb, IEEE80211_AC_VO); 212 skb->priority = 7; 213 214 info->control.vif = &sdata->vif; 215 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING; 216 ieee80211_set_qos_hdr(sdata, skb); 217 ieee80211_mps_set_frame_flags(sdata, NULL, hdr); 218 } 219 220 /** 221 * mesh_path_error_tx - Sends a PERR mesh management frame 222 * 223 * @ttl: allowed remaining hops 224 * @target: broken destination 225 * @target_sn: SN of the broken destination 226 * @target_rcode: reason code for this PERR 227 * @ra: node this frame is addressed to 228 * @sdata: local mesh subif 229 * 230 * Note: This function may be called with driver locks taken that the driver 231 * also acquires in the TX path. To avoid a deadlock we don't transmit the 232 * frame directly but add it to the pending queue instead. 233 * 234 * Returns: 0 on success 235 */ mesh_path_error_tx(struct ieee80211_sub_if_data * sdata,u8 ttl,const u8 * target,u32 target_sn,u16 target_rcode,const u8 * ra)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 IEEE80211_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 + IEEE80211_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 ieee80211s_update_metric(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_tx_status * st)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 /* use rate info set by the driver directly if present */ 316 if (st->n_rates) 317 rinfo = sta->deflink.tx_stats.last_rate_info; 318 else 319 sta_set_rate_info_tx(sta, &sta->deflink.tx_stats.last_rate, &rinfo); 320 321 ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg, 322 cfg80211_calculate_bitrate(&rinfo)); 323 } 324 airtime_link_metric_get(struct ieee80211_local * local,struct sta_info * sta)325 u32 airtime_link_metric_get(struct ieee80211_local *local, 326 struct sta_info *sta) 327 { 328 /* This should be adjusted for each device */ 329 int device_constant = 1 << ARITH_SHIFT; 330 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 331 int s_unit = 1 << ARITH_SHIFT; 332 int rate, err; 333 u32 tx_time, estimated_retx; 334 u64 result; 335 unsigned long fail_avg = 336 ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); 337 338 if (sta->mesh->plink_state != NL80211_PLINK_ESTAB) 339 return MAX_METRIC; 340 341 /* Try to get rate based on HW/SW RC algorithm. 342 * Rate is returned in units of Kbps, correct this 343 * to comply with airtime calculation units 344 * Round up in case we get rate < 100Kbps 345 */ 346 rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); 347 348 if (rate) { 349 err = 0; 350 } else { 351 if (fail_avg > LINK_FAIL_THRESH) 352 return MAX_METRIC; 353 354 rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg); 355 if (WARN_ON(!rate)) 356 return MAX_METRIC; 357 358 err = (fail_avg << ARITH_SHIFT) / 100; 359 } 360 361 /* bitrate is in units of 100 Kbps, while we need rate in units of 362 * 1Mbps. This will be corrected on tx_time computation. 363 */ 364 tx_time = (device_constant + 10 * test_frame_len / rate); 365 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 366 result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT); 367 return (u32)result; 368 } 369 370 /** 371 * hwmp_route_info_get - Update routing info to originator and transmitter 372 * 373 * @sdata: local mesh subif 374 * @mgmt: mesh management frame 375 * @hwmp_ie: hwmp information element (PREP or PREQ) 376 * @action: type of hwmp ie 377 * 378 * This function updates the path routing information to the originator and the 379 * transmitter of a HWMP PREQ or PREP frame. 380 * 381 * Returns: metric to frame originator or 0 if the frame should not be further 382 * processed 383 * 384 * Notes: this function is the only place (besides user-provided info) where 385 * path routing information is updated. 386 */ hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)387 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 388 struct ieee80211_mgmt *mgmt, 389 const u8 *hwmp_ie, enum mpath_frame_type action) 390 { 391 struct ieee80211_local *local = sdata->local; 392 struct mesh_path *mpath; 393 struct sta_info *sta; 394 bool fresh_info; 395 const u8 *orig_addr, *ta; 396 u32 orig_sn, orig_metric; 397 unsigned long orig_lifetime, exp_time; 398 u32 last_hop_metric, new_metric; 399 bool flush_mpath = false; 400 bool process = true; 401 u8 hopcount; 402 403 rcu_read_lock(); 404 sta = sta_info_get(sdata, mgmt->sa); 405 if (!sta) { 406 rcu_read_unlock(); 407 return 0; 408 } 409 410 last_hop_metric = airtime_link_metric_get(local, sta); 411 /* Update and check originator routing info */ 412 fresh_info = true; 413 414 switch (action) { 415 case MPATH_PREQ: 416 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 417 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 418 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 419 orig_metric = PREQ_IE_METRIC(hwmp_ie); 420 hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1; 421 break; 422 case MPATH_PREP: 423 /* Originator here refers to the MP that was the target in the 424 * Path Request. We divert from the nomenclature in the draft 425 * so that we can easily use a single function to gather path 426 * information from both PREQ and PREP frames. 427 */ 428 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 429 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 430 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 431 orig_metric = PREP_IE_METRIC(hwmp_ie); 432 hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1; 433 break; 434 default: 435 rcu_read_unlock(); 436 return 0; 437 } 438 new_metric = orig_metric + last_hop_metric; 439 if (new_metric < orig_metric) 440 new_metric = MAX_METRIC; 441 exp_time = TU_TO_EXP_TIME(orig_lifetime); 442 443 if (ether_addr_equal(orig_addr, sdata->vif.addr)) { 444 /* This MP is the originator, we are not interested in this 445 * frame, except for updating transmitter's path info. 446 */ 447 process = false; 448 fresh_info = false; 449 } else { 450 mpath = mesh_path_lookup(sdata, orig_addr); 451 if (mpath) { 452 spin_lock_bh(&mpath->state_lock); 453 if (mpath->flags & MESH_PATH_FIXED) 454 fresh_info = false; 455 else if ((mpath->flags & MESH_PATH_ACTIVE) && 456 (mpath->flags & MESH_PATH_SN_VALID)) { 457 if (SN_GT(mpath->sn, orig_sn) || 458 (mpath->sn == orig_sn && 459 (rcu_access_pointer(mpath->next_hop) != 460 sta ? 461 mult_frac(new_metric, 10, 9) : 462 new_metric) >= mpath->metric)) { 463 process = false; 464 fresh_info = false; 465 } 466 } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { 467 bool have_sn, newer_sn, bounced; 468 469 have_sn = mpath->flags & MESH_PATH_SN_VALID; 470 newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); 471 bounced = have_sn && 472 (SN_DELTA(orig_sn, mpath->sn) > 473 MAX_SANE_SN_DELTA); 474 475 if (!have_sn || newer_sn) { 476 /* if SN is newer than what we had 477 * then we can take it */; 478 } else if (bounced) { 479 /* if SN is way different than what 480 * we had then assume the other side 481 * rebooted or restarted */; 482 } else { 483 process = false; 484 fresh_info = false; 485 } 486 } 487 } else { 488 mpath = mesh_path_add(sdata, orig_addr); 489 if (IS_ERR(mpath)) { 490 rcu_read_unlock(); 491 return 0; 492 } 493 spin_lock_bh(&mpath->state_lock); 494 } 495 496 if (fresh_info) { 497 if (rcu_access_pointer(mpath->next_hop) != sta) { 498 mpath->path_change_count++; 499 flush_mpath = true; 500 } 501 mesh_path_assign_nexthop(mpath, sta); 502 mpath->flags |= MESH_PATH_SN_VALID; 503 mpath->metric = new_metric; 504 mpath->sn = orig_sn; 505 mpath->exp_time = time_after(mpath->exp_time, exp_time) 506 ? mpath->exp_time : exp_time; 507 mpath->hop_count = hopcount; 508 mesh_path_activate(mpath); 509 spin_unlock_bh(&mpath->state_lock); 510 if (flush_mpath) 511 mesh_fast_tx_flush_mpath(mpath); 512 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 513 /* init it at a low value - 0 start is tricky */ 514 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 515 mesh_path_tx_pending(mpath); 516 /* draft says preq_id should be saved to, but there does 517 * not seem to be any use for it, skipping by now 518 */ 519 } else 520 spin_unlock_bh(&mpath->state_lock); 521 } 522 523 /* Update and check transmitter routing info */ 524 ta = mgmt->sa; 525 if (ether_addr_equal(orig_addr, ta)) 526 fresh_info = false; 527 else { 528 fresh_info = true; 529 530 mpath = mesh_path_lookup(sdata, ta); 531 if (mpath) { 532 spin_lock_bh(&mpath->state_lock); 533 if ((mpath->flags & MESH_PATH_FIXED) || 534 ((mpath->flags & MESH_PATH_ACTIVE) && 535 ((rcu_access_pointer(mpath->next_hop) != sta ? 536 mult_frac(last_hop_metric, 10, 9) : 537 last_hop_metric) > mpath->metric))) 538 fresh_info = false; 539 } else { 540 mpath = mesh_path_add(sdata, ta); 541 if (IS_ERR(mpath)) { 542 rcu_read_unlock(); 543 return 0; 544 } 545 spin_lock_bh(&mpath->state_lock); 546 } 547 548 if (fresh_info) { 549 if (rcu_access_pointer(mpath->next_hop) != sta) { 550 mpath->path_change_count++; 551 flush_mpath = true; 552 } 553 mesh_path_assign_nexthop(mpath, sta); 554 mpath->metric = last_hop_metric; 555 mpath->exp_time = time_after(mpath->exp_time, exp_time) 556 ? mpath->exp_time : exp_time; 557 mpath->hop_count = 1; 558 mesh_path_activate(mpath); 559 spin_unlock_bh(&mpath->state_lock); 560 if (flush_mpath) 561 mesh_fast_tx_flush_mpath(mpath); 562 ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); 563 /* init it at a low value - 0 start is tricky */ 564 ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); 565 mesh_path_tx_pending(mpath); 566 } else 567 spin_unlock_bh(&mpath->state_lock); 568 } 569 570 rcu_read_unlock(); 571 572 return process ? new_metric : 0; 573 } 574 hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 orig_metric)575 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 576 struct ieee80211_mgmt *mgmt, 577 const u8 *preq_elem, u32 orig_metric) 578 { 579 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 580 struct mesh_path *mpath = NULL; 581 const u8 *target_addr, *orig_addr; 582 const u8 *da; 583 u8 target_flags, ttl, flags; 584 u32 orig_sn, target_sn, lifetime, target_metric = 0; 585 bool reply = false; 586 bool forward = true; 587 bool root_is_gate; 588 589 /* Update target SN, if present */ 590 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 591 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 592 target_sn = PREQ_IE_TARGET_SN(preq_elem); 593 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 594 target_flags = PREQ_IE_TARGET_F(preq_elem); 595 /* Proactive PREQ gate announcements */ 596 flags = PREQ_IE_FLAGS(preq_elem); 597 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 598 599 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); 600 601 if (ether_addr_equal(target_addr, sdata->vif.addr)) { 602 mhwmp_dbg(sdata, "PREQ is for us\n"); 603 forward = false; 604 reply = true; 605 target_metric = 0; 606 607 if (SN_GT(target_sn, ifmsh->sn)) 608 ifmsh->sn = target_sn; 609 610 if (time_after(jiffies, ifmsh->last_sn_update + 611 net_traversal_jiffies(sdata)) || 612 time_before(jiffies, ifmsh->last_sn_update)) { 613 ++ifmsh->sn; 614 ifmsh->last_sn_update = jiffies; 615 } 616 target_sn = ifmsh->sn; 617 } else if (is_broadcast_ether_addr(target_addr) && 618 (target_flags & IEEE80211_PREQ_TO_FLAG)) { 619 rcu_read_lock(); 620 mpath = mesh_path_lookup(sdata, orig_addr); 621 if (mpath) { 622 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 623 reply = true; 624 target_addr = sdata->vif.addr; 625 target_sn = ++ifmsh->sn; 626 target_metric = 0; 627 ifmsh->last_sn_update = jiffies; 628 } 629 if (root_is_gate) 630 mesh_path_add_gate(mpath); 631 } 632 rcu_read_unlock(); 633 } else { 634 rcu_read_lock(); 635 mpath = mesh_path_lookup(sdata, target_addr); 636 if (mpath) { 637 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 638 SN_LT(mpath->sn, target_sn)) { 639 mpath->sn = target_sn; 640 mpath->flags |= MESH_PATH_SN_VALID; 641 } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && 642 (mpath->flags & MESH_PATH_ACTIVE)) { 643 reply = true; 644 target_metric = mpath->metric; 645 target_sn = mpath->sn; 646 /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ 647 target_flags |= IEEE80211_PREQ_TO_FLAG; 648 } 649 } 650 rcu_read_unlock(); 651 } 652 653 if (reply) { 654 lifetime = PREQ_IE_LIFETIME(preq_elem); 655 ttl = ifmsh->mshcfg.element_ttl; 656 if (ttl != 0) { 657 mhwmp_dbg(sdata, "replying to the PREQ\n"); 658 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 659 orig_sn, 0, target_addr, 660 target_sn, mgmt->sa, 0, ttl, 661 lifetime, target_metric, 0, 662 sdata); 663 } else { 664 ifmsh->mshstats.dropped_frames_ttl++; 665 } 666 } 667 668 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 669 u32 preq_id; 670 u8 hopcount; 671 672 ttl = PREQ_IE_TTL(preq_elem); 673 lifetime = PREQ_IE_LIFETIME(preq_elem); 674 if (ttl <= 1) { 675 ifmsh->mshstats.dropped_frames_ttl++; 676 return; 677 } 678 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); 679 --ttl; 680 preq_id = PREQ_IE_PREQ_ID(preq_elem); 681 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 682 da = (mpath && mpath->is_root) ? 683 mpath->rann_snd_addr : broadcast_addr; 684 685 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { 686 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 687 target_sn = PREQ_IE_TARGET_SN(preq_elem); 688 } 689 690 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 691 orig_sn, target_flags, target_addr, 692 target_sn, da, hopcount, ttl, lifetime, 693 orig_metric, preq_id, sdata); 694 if (!is_multicast_ether_addr(da)) 695 ifmsh->mshstats.fwded_unicast++; 696 else 697 ifmsh->mshstats.fwded_mcast++; 698 ifmsh->mshstats.fwded_frames++; 699 } 700 } 701 702 703 static inline struct sta_info * next_hop_deref_protected(struct mesh_path * mpath)704 next_hop_deref_protected(struct mesh_path *mpath) 705 { 706 return rcu_dereference_protected(mpath->next_hop, 707 lockdep_is_held(&mpath->state_lock)); 708 } 709 710 hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)711 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 712 struct ieee80211_mgmt *mgmt, 713 const u8 *prep_elem, u32 metric) 714 { 715 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 716 struct mesh_path *mpath; 717 const u8 *target_addr, *orig_addr; 718 u8 ttl, hopcount, flags; 719 u8 next_hop[ETH_ALEN]; 720 u32 target_sn, orig_sn, lifetime; 721 722 mhwmp_dbg(sdata, "received PREP from %pM\n", 723 PREP_IE_TARGET_ADDR(prep_elem)); 724 725 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 726 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 727 /* destination, no forwarding required */ 728 return; 729 730 if (!ifmsh->mshcfg.dot11MeshForwarding) 731 return; 732 733 ttl = PREP_IE_TTL(prep_elem); 734 if (ttl <= 1) { 735 sdata->u.mesh.mshstats.dropped_frames_ttl++; 736 return; 737 } 738 739 rcu_read_lock(); 740 mpath = mesh_path_lookup(sdata, orig_addr); 741 if (mpath) 742 spin_lock_bh(&mpath->state_lock); 743 else 744 goto fail; 745 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 746 spin_unlock_bh(&mpath->state_lock); 747 goto fail; 748 } 749 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 750 spin_unlock_bh(&mpath->state_lock); 751 --ttl; 752 flags = PREP_IE_FLAGS(prep_elem); 753 lifetime = PREP_IE_LIFETIME(prep_elem); 754 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 755 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 756 target_sn = PREP_IE_TARGET_SN(prep_elem); 757 orig_sn = PREP_IE_ORIG_SN(prep_elem); 758 759 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, 760 target_addr, target_sn, next_hop, hopcount, 761 ttl, lifetime, metric, 0, sdata); 762 rcu_read_unlock(); 763 764 sdata->u.mesh.mshstats.fwded_unicast++; 765 sdata->u.mesh.mshstats.fwded_frames++; 766 return; 767 768 fail: 769 rcu_read_unlock(); 770 sdata->u.mesh.mshstats.dropped_frames_no_route++; 771 } 772 hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)773 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 774 struct ieee80211_mgmt *mgmt, 775 const u8 *perr_elem) 776 { 777 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 778 struct mesh_path *mpath; 779 u8 ttl; 780 const u8 *ta, *target_addr; 781 u32 target_sn; 782 u16 target_rcode; 783 784 ta = mgmt->sa; 785 ttl = PERR_IE_TTL(perr_elem); 786 if (ttl <= 1) { 787 ifmsh->mshstats.dropped_frames_ttl++; 788 return; 789 } 790 ttl--; 791 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 792 target_sn = PERR_IE_TARGET_SN(perr_elem); 793 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 794 795 rcu_read_lock(); 796 mpath = mesh_path_lookup(sdata, target_addr); 797 if (mpath) { 798 struct sta_info *sta; 799 800 spin_lock_bh(&mpath->state_lock); 801 sta = next_hop_deref_protected(mpath); 802 if (mpath->flags & MESH_PATH_ACTIVE && 803 ether_addr_equal(ta, sta->sta.addr) && 804 !(mpath->flags & MESH_PATH_FIXED) && 805 (!(mpath->flags & MESH_PATH_SN_VALID) || 806 SN_GT(target_sn, mpath->sn) || target_sn == 0)) { 807 mpath->flags &= ~MESH_PATH_ACTIVE; 808 if (target_sn != 0) 809 mpath->sn = target_sn; 810 else 811 mpath->sn += 1; 812 spin_unlock_bh(&mpath->state_lock); 813 if (!ifmsh->mshcfg.dot11MeshForwarding) 814 goto endperr; 815 mesh_path_error_tx(sdata, ttl, target_addr, 816 target_sn, target_rcode, 817 broadcast_addr); 818 } else 819 spin_unlock_bh(&mpath->state_lock); 820 } 821 endperr: 822 rcu_read_unlock(); 823 } 824 hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)825 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 826 struct ieee80211_mgmt *mgmt, 827 const struct ieee80211_rann_ie *rann) 828 { 829 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 830 struct ieee80211_local *local = sdata->local; 831 struct sta_info *sta; 832 struct mesh_path *mpath; 833 u8 ttl, flags, hopcount; 834 const u8 *orig_addr; 835 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; 836 bool root_is_gate; 837 838 ttl = rann->rann_ttl; 839 flags = rann->rann_flags; 840 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 841 orig_addr = rann->rann_addr; 842 orig_sn = le32_to_cpu(rann->rann_seq); 843 interval = le32_to_cpu(rann->rann_interval); 844 hopcount = rann->rann_hopcount; 845 hopcount++; 846 orig_metric = le32_to_cpu(rann->rann_metric); 847 848 /* Ignore our own RANNs */ 849 if (ether_addr_equal(orig_addr, sdata->vif.addr)) 850 return; 851 852 mhwmp_dbg(sdata, 853 "received RANN from %pM via neighbour %pM (is_gate=%d)\n", 854 orig_addr, mgmt->sa, root_is_gate); 855 856 rcu_read_lock(); 857 sta = sta_info_get(sdata, mgmt->sa); 858 if (!sta) { 859 rcu_read_unlock(); 860 return; 861 } 862 863 last_hop_metric = airtime_link_metric_get(local, sta); 864 new_metric = orig_metric + last_hop_metric; 865 if (new_metric < orig_metric) 866 new_metric = MAX_METRIC; 867 868 mpath = mesh_path_lookup(sdata, orig_addr); 869 if (!mpath) { 870 mpath = mesh_path_add(sdata, orig_addr); 871 if (IS_ERR(mpath)) { 872 rcu_read_unlock(); 873 sdata->u.mesh.mshstats.dropped_frames_no_route++; 874 return; 875 } 876 } 877 878 if (!(SN_LT(mpath->sn, orig_sn)) && 879 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { 880 rcu_read_unlock(); 881 return; 882 } 883 884 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 885 (time_after(jiffies, mpath->last_preq_to_root + 886 root_path_confirmation_jiffies(sdata)) || 887 time_before(jiffies, mpath->last_preq_to_root))) && 888 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { 889 mhwmp_dbg(sdata, 890 "time to refresh root mpath %pM\n", 891 orig_addr); 892 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 893 mpath->last_preq_to_root = jiffies; 894 } 895 896 mpath->sn = orig_sn; 897 mpath->rann_metric = new_metric; 898 mpath->is_root = true; 899 /* Recording RANNs sender address to send individually 900 * addressed PREQs destined for root mesh STA */ 901 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 902 903 if (root_is_gate) 904 mesh_path_add_gate(mpath); 905 906 if (ttl <= 1) { 907 ifmsh->mshstats.dropped_frames_ttl++; 908 rcu_read_unlock(); 909 return; 910 } 911 ttl--; 912 913 if (ifmsh->mshcfg.dot11MeshForwarding) { 914 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 915 orig_sn, 0, NULL, 0, broadcast_addr, 916 hopcount, ttl, interval, 917 new_metric, 0, sdata); 918 } 919 920 rcu_read_unlock(); 921 } 922 923 mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)924 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 925 struct ieee80211_mgmt *mgmt, size_t len) 926 { 927 struct ieee802_11_elems *elems; 928 size_t baselen; 929 u32 path_metric; 930 struct sta_info *sta; 931 932 /* need action_code */ 933 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 934 return; 935 936 rcu_read_lock(); 937 sta = sta_info_get(sdata, mgmt->sa); 938 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 939 rcu_read_unlock(); 940 return; 941 } 942 rcu_read_unlock(); 943 944 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 945 elems = ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 946 len - baselen, false, NULL); 947 if (!elems) 948 return; 949 950 if (elems->preq) { 951 if (elems->preq_len != 37) 952 /* Right now we support just 1 destination and no AE */ 953 goto free; 954 path_metric = hwmp_route_info_get(sdata, mgmt, elems->preq, 955 MPATH_PREQ); 956 if (path_metric) 957 hwmp_preq_frame_process(sdata, mgmt, elems->preq, 958 path_metric); 959 } 960 if (elems->prep) { 961 if (elems->prep_len != 31) 962 /* Right now we support no AE */ 963 goto free; 964 path_metric = hwmp_route_info_get(sdata, mgmt, elems->prep, 965 MPATH_PREP); 966 if (path_metric) 967 hwmp_prep_frame_process(sdata, mgmt, elems->prep, 968 path_metric); 969 } 970 if (elems->perr) { 971 if (elems->perr_len != 15) 972 /* Right now we support only one destination per PERR */ 973 goto free; 974 hwmp_perr_frame_process(sdata, mgmt, elems->perr); 975 } 976 if (elems->rann) 977 hwmp_rann_frame_process(sdata, mgmt, elems->rann); 978 free: 979 kfree(elems); 980 } 981 982 /** 983 * mesh_queue_preq - queue a PREQ to a given destination 984 * 985 * @mpath: mesh path to discover 986 * @flags: special attributes of the PREQ to be sent 987 * 988 * Locking: the function must be called from within a rcu read lock block. 989 * 990 */ mesh_queue_preq(struct mesh_path * mpath,u8 flags)991 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 992 { 993 struct ieee80211_sub_if_data *sdata = mpath->sdata; 994 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 995 struct mesh_preq_queue *preq_node; 996 997 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 998 if (!preq_node) { 999 mhwmp_dbg(sdata, "could not allocate PREQ node\n"); 1000 return; 1001 } 1002 1003 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1004 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 1005 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1006 kfree(preq_node); 1007 if (printk_ratelimit()) 1008 mhwmp_dbg(sdata, "PREQ node queue full\n"); 1009 return; 1010 } 1011 1012 spin_lock(&mpath->state_lock); 1013 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 1014 spin_unlock(&mpath->state_lock); 1015 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1016 kfree(preq_node); 1017 return; 1018 } 1019 1020 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 1021 preq_node->flags = flags; 1022 1023 mpath->flags |= MESH_PATH_REQ_QUEUED; 1024 spin_unlock(&mpath->state_lock); 1025 1026 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 1027 ++ifmsh->preq_queue_len; 1028 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1029 1030 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 1031 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work); 1032 1033 else if (time_before(jiffies, ifmsh->last_preq)) { 1034 /* avoid long wait if did not send preqs for a long time 1035 * and jiffies wrapped around 1036 */ 1037 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 1038 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work); 1039 } else 1040 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 1041 min_preq_int_jiff(sdata)); 1042 } 1043 1044 /** 1045 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 1046 * 1047 * @sdata: local mesh subif 1048 */ mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)1049 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 1050 { 1051 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1052 struct mesh_preq_queue *preq_node; 1053 struct mesh_path *mpath; 1054 u8 ttl, target_flags = 0; 1055 const u8 *da; 1056 u32 lifetime; 1057 1058 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 1059 if (!ifmsh->preq_queue_len || 1060 time_before(jiffies, ifmsh->last_preq + 1061 min_preq_int_jiff(sdata))) { 1062 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1063 return; 1064 } 1065 1066 preq_node = list_first_entry(&ifmsh->preq_queue.list, 1067 struct mesh_preq_queue, list); 1068 list_del(&preq_node->list); 1069 --ifmsh->preq_queue_len; 1070 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 1071 1072 rcu_read_lock(); 1073 mpath = mesh_path_lookup(sdata, preq_node->dst); 1074 if (!mpath) 1075 goto enddiscovery; 1076 1077 spin_lock_bh(&mpath->state_lock); 1078 if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { 1079 spin_unlock_bh(&mpath->state_lock); 1080 goto enddiscovery; 1081 } 1082 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1083 if (preq_node->flags & PREQ_Q_F_START) { 1084 if (mpath->flags & MESH_PATH_RESOLVING) { 1085 spin_unlock_bh(&mpath->state_lock); 1086 goto enddiscovery; 1087 } else { 1088 mpath->flags &= ~MESH_PATH_RESOLVED; 1089 mpath->flags |= MESH_PATH_RESOLVING; 1090 mpath->discovery_retries = 0; 1091 mpath->discovery_timeout = disc_timeout_jiff(sdata); 1092 } 1093 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 1094 mpath->flags & MESH_PATH_RESOLVED) { 1095 mpath->flags &= ~MESH_PATH_RESOLVING; 1096 spin_unlock_bh(&mpath->state_lock); 1097 goto enddiscovery; 1098 } 1099 1100 ifmsh->last_preq = jiffies; 1101 1102 if (time_after(jiffies, ifmsh->last_sn_update + 1103 net_traversal_jiffies(sdata)) || 1104 time_before(jiffies, ifmsh->last_sn_update)) { 1105 ++ifmsh->sn; 1106 sdata->u.mesh.last_sn_update = jiffies; 1107 } 1108 lifetime = default_lifetime(sdata); 1109 ttl = sdata->u.mesh.mshcfg.element_ttl; 1110 if (ttl == 0) { 1111 sdata->u.mesh.mshstats.dropped_frames_ttl++; 1112 spin_unlock_bh(&mpath->state_lock); 1113 goto enddiscovery; 1114 } 1115 1116 if (preq_node->flags & PREQ_Q_F_REFRESH) 1117 target_flags |= IEEE80211_PREQ_TO_FLAG; 1118 else 1119 target_flags &= ~IEEE80211_PREQ_TO_FLAG; 1120 1121 spin_unlock_bh(&mpath->state_lock); 1122 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 1123 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, 1124 target_flags, mpath->dst, mpath->sn, da, 0, 1125 ttl, lifetime, 0, ifmsh->preq_id++, sdata); 1126 1127 spin_lock_bh(&mpath->state_lock); 1128 if (!(mpath->flags & MESH_PATH_DELETED)) 1129 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1130 spin_unlock_bh(&mpath->state_lock); 1131 1132 enddiscovery: 1133 rcu_read_unlock(); 1134 kfree(preq_node); 1135 } 1136 1137 /** 1138 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery 1139 * 1140 * @skb: 802.11 frame to be sent 1141 * @sdata: network subif the frame will be sent through 1142 * 1143 * Lookup next hop for given skb and start path discovery if no 1144 * forwarding information is found. 1145 * 1146 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1147 * skb is freed here if no mpath could be allocated. 1148 */ mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1149 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, 1150 struct sk_buff *skb) 1151 { 1152 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1153 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1154 struct mesh_path *mpath; 1155 struct sk_buff *skb_to_free = NULL; 1156 u8 *target_addr = hdr->addr3; 1157 1158 /* Nulls are only sent to peers for PS and should be pre-addressed */ 1159 if (ieee80211_is_qos_nullfunc(hdr->frame_control)) 1160 return 0; 1161 1162 /* Allow injected packets to bypass mesh routing */ 1163 if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP) 1164 return 0; 1165 1166 if (!mesh_nexthop_lookup(sdata, skb)) 1167 return 0; 1168 1169 /* no nexthop found, start resolving */ 1170 mpath = mesh_path_lookup(sdata, target_addr); 1171 if (!mpath) { 1172 mpath = mesh_path_add(sdata, target_addr); 1173 if (IS_ERR(mpath)) { 1174 mesh_path_discard_frame(sdata, skb); 1175 return PTR_ERR(mpath); 1176 } 1177 } 1178 1179 if (!(mpath->flags & MESH_PATH_RESOLVING) && 1180 mesh_path_sel_is_hwmp(sdata)) 1181 mesh_queue_preq(mpath, PREQ_Q_F_START); 1182 1183 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1184 skb_to_free = skb_dequeue(&mpath->frame_queue); 1185 1186 info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING; 1187 ieee80211_set_qos_hdr(sdata, skb); 1188 skb_queue_tail(&mpath->frame_queue, skb); 1189 if (skb_to_free) 1190 mesh_path_discard_frame(sdata, skb_to_free); 1191 1192 return -ENOENT; 1193 } 1194 1195 /** 1196 * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery 1197 * @skb: 802.11 frame to be sent 1198 * @sdata: network subif the frame will be sent through 1199 * 1200 * Check if the meshDA (addr3) of a unicast frame is a direct neighbor. 1201 * And if so, set the RA (addr1) to it to transmit to this node directly, 1202 * avoiding PREQ/PREP path discovery. 1203 * 1204 * Returns: 0 if the next hop was found and -ENOENT otherwise. 1205 */ mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1206 static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata, 1207 struct sk_buff *skb) 1208 { 1209 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 1210 struct sta_info *sta; 1211 1212 if (is_multicast_ether_addr(hdr->addr1)) 1213 return -ENOENT; 1214 1215 rcu_read_lock(); 1216 sta = sta_info_get(sdata, hdr->addr3); 1217 1218 if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { 1219 rcu_read_unlock(); 1220 return -ENOENT; 1221 } 1222 rcu_read_unlock(); 1223 1224 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN); 1225 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1226 return 0; 1227 } 1228 mesh_path_refresh(struct ieee80211_sub_if_data * sdata,struct mesh_path * mpath,const u8 * addr)1229 void mesh_path_refresh(struct ieee80211_sub_if_data *sdata, 1230 struct mesh_path *mpath, const u8 *addr) 1231 { 1232 if (mpath->flags & (MESH_PATH_REQ_QUEUED | MESH_PATH_FIXED | 1233 MESH_PATH_RESOLVING)) 1234 return; 1235 1236 if (time_after(jiffies, 1237 mpath->exp_time - 1238 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1239 (!addr || ether_addr_equal(sdata->vif.addr, addr))) 1240 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1241 } 1242 1243 /** 1244 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1245 * this function is considered "using" the associated mpath, so preempt a path 1246 * refresh if this mpath expires soon. 1247 * 1248 * @skb: 802.11 frame to be sent 1249 * @sdata: network subif the frame will be sent through 1250 * 1251 * Returns: 0 if the next hop was found. Nonzero otherwise. 1252 */ mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1253 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, 1254 struct sk_buff *skb) 1255 { 1256 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1257 struct mesh_path *mpath; 1258 struct sta_info *next_hop; 1259 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1260 u8 *target_addr = hdr->addr3; 1261 1262 if (ifmsh->mshcfg.dot11MeshNolearn && 1263 !mesh_nexthop_lookup_nolearn(sdata, skb)) 1264 return 0; 1265 1266 mpath = mesh_path_lookup(sdata, target_addr); 1267 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1268 return -ENOENT; 1269 1270 mesh_path_refresh(sdata, mpath, hdr->addr4); 1271 1272 next_hop = rcu_dereference(mpath->next_hop); 1273 if (next_hop) { 1274 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1275 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1276 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); 1277 if (ieee80211_hw_check(&sdata->local->hw, SUPPORT_FAST_XMIT)) 1278 mesh_fast_tx_cache(sdata, skb, mpath); 1279 return 0; 1280 } 1281 1282 return -ENOENT; 1283 } 1284 mesh_path_timer(struct timer_list * t)1285 void mesh_path_timer(struct timer_list *t) 1286 { 1287 struct mesh_path *mpath = from_timer(mpath, t, timer); 1288 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1289 int ret; 1290 1291 if (sdata->local->quiescing) 1292 return; 1293 1294 spin_lock_bh(&mpath->state_lock); 1295 if (mpath->flags & MESH_PATH_RESOLVED || 1296 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1297 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1298 spin_unlock_bh(&mpath->state_lock); 1299 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1300 ++mpath->discovery_retries; 1301 mpath->discovery_timeout *= 2; 1302 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1303 spin_unlock_bh(&mpath->state_lock); 1304 mesh_queue_preq(mpath, 0); 1305 } else { 1306 mpath->flags &= ~(MESH_PATH_RESOLVING | 1307 MESH_PATH_RESOLVED | 1308 MESH_PATH_REQ_QUEUED); 1309 mpath->exp_time = jiffies; 1310 spin_unlock_bh(&mpath->state_lock); 1311 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1312 ret = mesh_path_send_to_gates(mpath); 1313 if (ret) 1314 mhwmp_dbg(sdata, "no gate was reachable\n"); 1315 } else 1316 mesh_path_flush_pending(mpath); 1317 } 1318 } 1319 mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1320 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1321 { 1322 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1323 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1324 u8 flags, target_flags = 0; 1325 1326 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1327 ? RANN_FLAG_IS_GATE : 0; 1328 1329 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { 1330 case IEEE80211_PROACTIVE_RANN: 1331 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1332 ++ifmsh->sn, 0, NULL, 0, broadcast_addr, 1333 0, ifmsh->mshcfg.element_ttl, 1334 interval, 0, 0, sdata); 1335 break; 1336 case IEEE80211_PROACTIVE_PREQ_WITH_PREP: 1337 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; 1338 fallthrough; 1339 case IEEE80211_PROACTIVE_PREQ_NO_PREP: 1340 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; 1341 target_flags |= IEEE80211_PREQ_TO_FLAG | 1342 IEEE80211_PREQ_USN_FLAG; 1343 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, 1344 ++ifmsh->sn, target_flags, 1345 (u8 *) broadcast_addr, 0, broadcast_addr, 1346 0, ifmsh->mshcfg.element_ttl, interval, 1347 0, ifmsh->preq_id++, sdata); 1348 break; 1349 default: 1350 mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); 1351 return; 1352 } 1353 } 1354