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 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG 17 #define mhwmp_dbg(fmt, args...) \ 18 printk(KERN_DEBUG "Mesh HWMP (%s): " fmt "\n", sdata->name, ##args) 19 #else 20 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0) 21 #endif 22 23 #define TEST_FRAME_LEN 8192 24 #define MAX_METRIC 0xffffffff 25 #define ARITH_SHIFT 8 26 27 /* Number of frames buffered per destination for unresolved destinations */ 28 #define MESH_FRAME_QUEUE_LEN 10 29 #define MAX_PREQ_QUEUE_LEN 64 30 31 /* Destination only */ 32 #define MP_F_DO 0x1 33 /* Reply and forward */ 34 #define MP_F_RF 0x2 35 /* Unknown Sequence Number */ 36 #define MP_F_USN 0x01 37 /* Reason code Present */ 38 #define MP_F_RCODE 0x02 39 40 static void mesh_queue_preq(struct mesh_path *, u8); 41 42 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae) 43 { 44 if (ae) 45 offset += 6; 46 return get_unaligned_le32(preq_elem + offset); 47 } 48 49 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae) 50 { 51 if (ae) 52 offset += 6; 53 return get_unaligned_le16(preq_elem + offset); 54 } 55 56 /* HWMP IE processing macros */ 57 #define AE_F (1<<6) 58 #define AE_F_SET(x) (*x & AE_F) 59 #define PREQ_IE_FLAGS(x) (*(x)) 60 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 61 #define PREQ_IE_TTL(x) (*(x + 2)) 62 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 63 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 64 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0) 65 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)) 66 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)) 67 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 68 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 69 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)) 70 71 72 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 73 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 74 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 75 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 76 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x)) 77 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)) 78 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)) 79 #define PREP_IE_TARGET_ADDR(x) (x + 3) 80 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 81 82 #define PERR_IE_TTL(x) (*(x)) 83 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 84 #define PERR_IE_TARGET_ADDR(x) (x + 3) 85 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 86 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) 87 88 #define MSEC_TO_TU(x) (x*1000/1024) 89 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0) 90 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0) 91 92 #define net_traversal_jiffies(s) \ 93 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 94 #define default_lifetime(s) \ 95 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 96 #define min_preq_int_jiff(s) \ 97 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 98 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 99 #define disc_timeout_jiff(s) \ 100 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 101 102 enum mpath_frame_type { 103 MPATH_PREQ = 0, 104 MPATH_PREP, 105 MPATH_PERR, 106 MPATH_RANN 107 }; 108 109 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 110 111 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 112 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target, 113 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl, 114 __le32 lifetime, __le32 metric, __le32 preq_id, 115 struct ieee80211_sub_if_data *sdata) 116 { 117 struct ieee80211_local *local = sdata->local; 118 struct sk_buff *skb; 119 struct ieee80211_mgmt *mgmt; 120 u8 *pos, ie_len; 121 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + 122 sizeof(mgmt->u.action.u.mesh_action); 123 124 skb = dev_alloc_skb(local->tx_headroom + 125 hdr_len + 126 2 + 37); /* max HWMP IE */ 127 if (!skb) 128 return -1; 129 skb_reserve(skb, local->tx_headroom); 130 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 131 memset(mgmt, 0, hdr_len); 132 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 133 IEEE80211_STYPE_ACTION); 134 135 memcpy(mgmt->da, da, ETH_ALEN); 136 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 137 /* BSSID == SA */ 138 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 139 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 140 mgmt->u.action.u.mesh_action.action_code = 141 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 142 143 switch (action) { 144 case MPATH_PREQ: 145 mhwmp_dbg("sending PREQ to %pM", target); 146 ie_len = 37; 147 pos = skb_put(skb, 2 + ie_len); 148 *pos++ = WLAN_EID_PREQ; 149 break; 150 case MPATH_PREP: 151 mhwmp_dbg("sending PREP to %pM", target); 152 ie_len = 31; 153 pos = skb_put(skb, 2 + ie_len); 154 *pos++ = WLAN_EID_PREP; 155 break; 156 case MPATH_RANN: 157 mhwmp_dbg("sending RANN from %pM", orig_addr); 158 ie_len = sizeof(struct ieee80211_rann_ie); 159 pos = skb_put(skb, 2 + ie_len); 160 *pos++ = WLAN_EID_RANN; 161 break; 162 default: 163 kfree_skb(skb); 164 return -ENOTSUPP; 165 break; 166 } 167 *pos++ = ie_len; 168 *pos++ = flags; 169 *pos++ = hop_count; 170 *pos++ = ttl; 171 if (action == MPATH_PREP) { 172 memcpy(pos, target, ETH_ALEN); 173 pos += ETH_ALEN; 174 memcpy(pos, &target_sn, 4); 175 pos += 4; 176 } else { 177 if (action == MPATH_PREQ) { 178 memcpy(pos, &preq_id, 4); 179 pos += 4; 180 } 181 memcpy(pos, orig_addr, ETH_ALEN); 182 pos += ETH_ALEN; 183 memcpy(pos, &orig_sn, 4); 184 pos += 4; 185 } 186 memcpy(pos, &lifetime, 4); /* interval for RANN */ 187 pos += 4; 188 memcpy(pos, &metric, 4); 189 pos += 4; 190 if (action == MPATH_PREQ) { 191 *pos++ = 1; /* destination count */ 192 *pos++ = target_flags; 193 memcpy(pos, target, ETH_ALEN); 194 pos += ETH_ALEN; 195 memcpy(pos, &target_sn, 4); 196 pos += 4; 197 } else if (action == MPATH_PREP) { 198 memcpy(pos, orig_addr, ETH_ALEN); 199 pos += ETH_ALEN; 200 memcpy(pos, &orig_sn, 4); 201 pos += 4; 202 } 203 204 ieee80211_tx_skb(sdata, skb); 205 return 0; 206 } 207 208 209 /* Headroom is not adjusted. Caller should ensure that skb has sufficient 210 * headroom in case the frame is encrypted. */ 211 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, 212 struct sk_buff *skb) 213 { 214 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 215 216 skb_set_mac_header(skb, 0); 217 skb_set_network_header(skb, 0); 218 skb_set_transport_header(skb, 0); 219 220 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ 221 skb_set_queue_mapping(skb, IEEE80211_AC_VO); 222 skb->priority = 7; 223 224 info->control.vif = &sdata->vif; 225 ieee80211_set_qos_hdr(sdata, skb); 226 } 227 228 /** 229 * mesh_send_path error - Sends a PERR mesh management frame 230 * 231 * @target: broken destination 232 * @target_sn: SN of the broken destination 233 * @target_rcode: reason code for this PERR 234 * @ra: node this frame is addressed to 235 * 236 * Note: This function may be called with driver locks taken that the driver 237 * also acquires in the TX path. To avoid a deadlock we don't transmit the 238 * frame directly but add it to the pending queue instead. 239 */ 240 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, 241 __le16 target_rcode, const u8 *ra, 242 struct ieee80211_sub_if_data *sdata) 243 { 244 struct ieee80211_local *local = sdata->local; 245 struct sk_buff *skb; 246 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 247 struct ieee80211_mgmt *mgmt; 248 u8 *pos, ie_len; 249 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + 250 sizeof(mgmt->u.action.u.mesh_action); 251 252 if (time_before(jiffies, ifmsh->next_perr)) 253 return -EAGAIN; 254 255 skb = dev_alloc_skb(local->tx_headroom + 256 hdr_len + 257 2 + 15 /* PERR IE */); 258 if (!skb) 259 return -1; 260 skb_reserve(skb, local->tx_headroom); 261 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 262 memset(mgmt, 0, hdr_len); 263 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 264 IEEE80211_STYPE_ACTION); 265 266 memcpy(mgmt->da, ra, ETH_ALEN); 267 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 268 /* BSSID == SA */ 269 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 270 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 271 mgmt->u.action.u.mesh_action.action_code = 272 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 273 ie_len = 15; 274 pos = skb_put(skb, 2 + ie_len); 275 *pos++ = WLAN_EID_PERR; 276 *pos++ = ie_len; 277 /* ttl */ 278 *pos++ = ttl; 279 /* number of destinations */ 280 *pos++ = 1; 281 /* 282 * flags bit, bit 1 is unset if we know the sequence number and 283 * bit 2 is set if we have a reason code 284 */ 285 *pos = 0; 286 if (!target_sn) 287 *pos |= MP_F_USN; 288 if (target_rcode) 289 *pos |= MP_F_RCODE; 290 pos++; 291 memcpy(pos, target, ETH_ALEN); 292 pos += ETH_ALEN; 293 memcpy(pos, &target_sn, 4); 294 pos += 4; 295 memcpy(pos, &target_rcode, 2); 296 297 /* see note in function header */ 298 prepare_frame_for_deferred_tx(sdata, skb); 299 ifmsh->next_perr = TU_TO_EXP_TIME( 300 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval); 301 ieee80211_add_pending_skb(local, skb); 302 return 0; 303 } 304 305 void ieee80211s_update_metric(struct ieee80211_local *local, 306 struct sta_info *stainfo, struct sk_buff *skb) 307 { 308 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); 309 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 310 int failed; 311 312 if (!ieee80211_is_data(hdr->frame_control)) 313 return; 314 315 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 316 317 /* moving average, scaled to 100 */ 318 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed); 319 if (stainfo->fail_avg > 95) 320 mesh_plink_broken(stainfo); 321 } 322 323 static u32 airtime_link_metric_get(struct ieee80211_local *local, 324 struct sta_info *sta) 325 { 326 struct ieee80211_supported_band *sband; 327 struct rate_info rinfo; 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; 335 336 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 337 338 if (sta->fail_avg >= 100) 339 return MAX_METRIC; 340 341 sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo); 342 rate = cfg80211_calculate_bitrate(&rinfo); 343 if (WARN_ON(!rate)) 344 return MAX_METRIC; 345 346 err = (sta->fail_avg << ARITH_SHIFT) / 100; 347 348 /* bitrate is in units of 100 Kbps, while we need rate in units of 349 * 1Mbps. This will be corrected on tx_time computation. 350 */ 351 tx_time = (device_constant + 10 * test_frame_len / rate); 352 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 353 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 354 return (u32)result; 355 } 356 357 /** 358 * hwmp_route_info_get - Update routing info to originator and transmitter 359 * 360 * @sdata: local mesh subif 361 * @mgmt: mesh management frame 362 * @hwmp_ie: hwmp information element (PREP or PREQ) 363 * 364 * This function updates the path routing information to the originator and the 365 * transmitter of a HWMP PREQ or PREP frame. 366 * 367 * Returns: metric to frame originator or 0 if the frame should not be further 368 * processed 369 * 370 * Notes: this function is the only place (besides user-provided info) where 371 * path routing information is updated. 372 */ 373 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 374 struct ieee80211_mgmt *mgmt, 375 u8 *hwmp_ie, enum mpath_frame_type action) 376 { 377 struct ieee80211_local *local = sdata->local; 378 struct mesh_path *mpath; 379 struct sta_info *sta; 380 bool fresh_info; 381 u8 *orig_addr, *ta; 382 u32 orig_sn, orig_metric; 383 unsigned long orig_lifetime, exp_time; 384 u32 last_hop_metric, new_metric; 385 bool process = true; 386 387 rcu_read_lock(); 388 sta = sta_info_get(sdata, mgmt->sa); 389 if (!sta) { 390 rcu_read_unlock(); 391 return 0; 392 } 393 394 last_hop_metric = airtime_link_metric_get(local, sta); 395 /* Update and check originator routing info */ 396 fresh_info = true; 397 398 switch (action) { 399 case MPATH_PREQ: 400 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 401 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 402 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 403 orig_metric = PREQ_IE_METRIC(hwmp_ie); 404 break; 405 case MPATH_PREP: 406 /* Originator here refers to the MP that was the target in the 407 * Path Request. We divert from the nomenclature in the draft 408 * so that we can easily use a single function to gather path 409 * information from both PREQ and PREP frames. 410 */ 411 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 412 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 413 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 414 orig_metric = PREP_IE_METRIC(hwmp_ie); 415 break; 416 default: 417 rcu_read_unlock(); 418 return 0; 419 } 420 new_metric = orig_metric + last_hop_metric; 421 if (new_metric < orig_metric) 422 new_metric = MAX_METRIC; 423 exp_time = TU_TO_EXP_TIME(orig_lifetime); 424 425 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0) { 426 /* This MP is the originator, we are not interested in this 427 * frame, except for updating transmitter's path info. 428 */ 429 process = false; 430 fresh_info = false; 431 } else { 432 mpath = mesh_path_lookup(orig_addr, sdata); 433 if (mpath) { 434 spin_lock_bh(&mpath->state_lock); 435 if (mpath->flags & MESH_PATH_FIXED) 436 fresh_info = false; 437 else if ((mpath->flags & MESH_PATH_ACTIVE) && 438 (mpath->flags & MESH_PATH_SN_VALID)) { 439 if (SN_GT(mpath->sn, orig_sn) || 440 (mpath->sn == orig_sn && 441 new_metric >= mpath->metric)) { 442 process = false; 443 fresh_info = false; 444 } 445 } 446 } else { 447 mesh_path_add(orig_addr, sdata); 448 mpath = mesh_path_lookup(orig_addr, sdata); 449 if (!mpath) { 450 rcu_read_unlock(); 451 return 0; 452 } 453 spin_lock_bh(&mpath->state_lock); 454 } 455 456 if (fresh_info) { 457 mesh_path_assign_nexthop(mpath, sta); 458 mpath->flags |= MESH_PATH_SN_VALID; 459 mpath->metric = new_metric; 460 mpath->sn = orig_sn; 461 mpath->exp_time = time_after(mpath->exp_time, exp_time) 462 ? mpath->exp_time : exp_time; 463 mesh_path_activate(mpath); 464 spin_unlock_bh(&mpath->state_lock); 465 mesh_path_tx_pending(mpath); 466 /* draft says preq_id should be saved to, but there does 467 * not seem to be any use for it, skipping by now 468 */ 469 } else 470 spin_unlock_bh(&mpath->state_lock); 471 } 472 473 /* Update and check transmitter routing info */ 474 ta = mgmt->sa; 475 if (compare_ether_addr(orig_addr, ta) == 0) 476 fresh_info = false; 477 else { 478 fresh_info = true; 479 480 mpath = mesh_path_lookup(ta, sdata); 481 if (mpath) { 482 spin_lock_bh(&mpath->state_lock); 483 if ((mpath->flags & MESH_PATH_FIXED) || 484 ((mpath->flags & MESH_PATH_ACTIVE) && 485 (last_hop_metric > mpath->metric))) 486 fresh_info = false; 487 } else { 488 mesh_path_add(ta, sdata); 489 mpath = mesh_path_lookup(ta, sdata); 490 if (!mpath) { 491 rcu_read_unlock(); 492 return 0; 493 } 494 spin_lock_bh(&mpath->state_lock); 495 } 496 497 if (fresh_info) { 498 mesh_path_assign_nexthop(mpath, sta); 499 mpath->metric = last_hop_metric; 500 mpath->exp_time = time_after(mpath->exp_time, exp_time) 501 ? mpath->exp_time : exp_time; 502 mesh_path_activate(mpath); 503 spin_unlock_bh(&mpath->state_lock); 504 mesh_path_tx_pending(mpath); 505 } else 506 spin_unlock_bh(&mpath->state_lock); 507 } 508 509 rcu_read_unlock(); 510 511 return process ? new_metric : 0; 512 } 513 514 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 515 struct ieee80211_mgmt *mgmt, 516 u8 *preq_elem, u32 metric) 517 { 518 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 519 struct mesh_path *mpath = NULL; 520 u8 *target_addr, *orig_addr; 521 const u8 *da; 522 u8 target_flags, ttl; 523 u32 orig_sn, target_sn, lifetime; 524 bool reply = false; 525 bool forward = true; 526 527 /* Update target SN, if present */ 528 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 529 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 530 target_sn = PREQ_IE_TARGET_SN(preq_elem); 531 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 532 target_flags = PREQ_IE_TARGET_F(preq_elem); 533 534 mhwmp_dbg("received PREQ from %pM", orig_addr); 535 536 if (compare_ether_addr(target_addr, sdata->vif.addr) == 0) { 537 mhwmp_dbg("PREQ is for us"); 538 forward = false; 539 reply = true; 540 metric = 0; 541 if (time_after(jiffies, ifmsh->last_sn_update + 542 net_traversal_jiffies(sdata)) || 543 time_before(jiffies, ifmsh->last_sn_update)) { 544 target_sn = ++ifmsh->sn; 545 ifmsh->last_sn_update = jiffies; 546 } 547 } else { 548 rcu_read_lock(); 549 mpath = mesh_path_lookup(target_addr, sdata); 550 if (mpath) { 551 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 552 SN_LT(mpath->sn, target_sn)) { 553 mpath->sn = target_sn; 554 mpath->flags |= MESH_PATH_SN_VALID; 555 } else if ((!(target_flags & MP_F_DO)) && 556 (mpath->flags & MESH_PATH_ACTIVE)) { 557 reply = true; 558 metric = mpath->metric; 559 target_sn = mpath->sn; 560 if (target_flags & MP_F_RF) 561 target_flags |= MP_F_DO; 562 else 563 forward = false; 564 } 565 } 566 rcu_read_unlock(); 567 } 568 569 if (reply) { 570 lifetime = PREQ_IE_LIFETIME(preq_elem); 571 ttl = ifmsh->mshcfg.element_ttl; 572 if (ttl != 0) { 573 mhwmp_dbg("replying to the PREQ"); 574 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 575 cpu_to_le32(orig_sn), 0, target_addr, 576 cpu_to_le32(target_sn), mgmt->sa, 0, ttl, 577 cpu_to_le32(lifetime), cpu_to_le32(metric), 578 0, sdata); 579 } else 580 ifmsh->mshstats.dropped_frames_ttl++; 581 } 582 583 if (forward && ifmsh->mshcfg.dot11MeshForwarding) { 584 u32 preq_id; 585 u8 hopcount, flags; 586 587 ttl = PREQ_IE_TTL(preq_elem); 588 lifetime = PREQ_IE_LIFETIME(preq_elem); 589 if (ttl <= 1) { 590 ifmsh->mshstats.dropped_frames_ttl++; 591 return; 592 } 593 mhwmp_dbg("forwarding the PREQ from %pM", orig_addr); 594 --ttl; 595 flags = PREQ_IE_FLAGS(preq_elem); 596 preq_id = PREQ_IE_PREQ_ID(preq_elem); 597 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 598 da = (mpath && mpath->is_root) ? 599 mpath->rann_snd_addr : broadcast_addr; 600 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 601 cpu_to_le32(orig_sn), target_flags, target_addr, 602 cpu_to_le32(target_sn), da, 603 hopcount, ttl, cpu_to_le32(lifetime), 604 cpu_to_le32(metric), cpu_to_le32(preq_id), 605 sdata); 606 ifmsh->mshstats.fwded_mcast++; 607 ifmsh->mshstats.fwded_frames++; 608 } 609 } 610 611 612 static inline struct sta_info * 613 next_hop_deref_protected(struct mesh_path *mpath) 614 { 615 return rcu_dereference_protected(mpath->next_hop, 616 lockdep_is_held(&mpath->state_lock)); 617 } 618 619 620 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 621 struct ieee80211_mgmt *mgmt, 622 u8 *prep_elem, u32 metric) 623 { 624 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 625 struct mesh_path *mpath; 626 u8 *target_addr, *orig_addr; 627 u8 ttl, hopcount, flags; 628 u8 next_hop[ETH_ALEN]; 629 u32 target_sn, orig_sn, lifetime; 630 631 mhwmp_dbg("received PREP from %pM", PREP_IE_ORIG_ADDR(prep_elem)); 632 633 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 634 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0) 635 /* destination, no forwarding required */ 636 return; 637 638 if (!ifmsh->mshcfg.dot11MeshForwarding) 639 return; 640 641 ttl = PREP_IE_TTL(prep_elem); 642 if (ttl <= 1) { 643 sdata->u.mesh.mshstats.dropped_frames_ttl++; 644 return; 645 } 646 647 rcu_read_lock(); 648 mpath = mesh_path_lookup(orig_addr, sdata); 649 if (mpath) 650 spin_lock_bh(&mpath->state_lock); 651 else 652 goto fail; 653 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 654 spin_unlock_bh(&mpath->state_lock); 655 goto fail; 656 } 657 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 658 spin_unlock_bh(&mpath->state_lock); 659 --ttl; 660 flags = PREP_IE_FLAGS(prep_elem); 661 lifetime = PREP_IE_LIFETIME(prep_elem); 662 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 663 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 664 target_sn = PREP_IE_TARGET_SN(prep_elem); 665 orig_sn = PREP_IE_ORIG_SN(prep_elem); 666 667 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 668 cpu_to_le32(orig_sn), 0, target_addr, 669 cpu_to_le32(target_sn), next_hop, hopcount, 670 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric), 671 0, sdata); 672 rcu_read_unlock(); 673 674 sdata->u.mesh.mshstats.fwded_unicast++; 675 sdata->u.mesh.mshstats.fwded_frames++; 676 return; 677 678 fail: 679 rcu_read_unlock(); 680 sdata->u.mesh.mshstats.dropped_frames_no_route++; 681 } 682 683 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 684 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 685 { 686 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 687 struct mesh_path *mpath; 688 u8 ttl; 689 u8 *ta, *target_addr; 690 u32 target_sn; 691 u16 target_rcode; 692 693 ta = mgmt->sa; 694 ttl = PERR_IE_TTL(perr_elem); 695 if (ttl <= 1) { 696 ifmsh->mshstats.dropped_frames_ttl++; 697 return; 698 } 699 ttl--; 700 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 701 target_sn = PERR_IE_TARGET_SN(perr_elem); 702 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 703 704 rcu_read_lock(); 705 mpath = mesh_path_lookup(target_addr, sdata); 706 if (mpath) { 707 struct sta_info *sta; 708 709 spin_lock_bh(&mpath->state_lock); 710 sta = next_hop_deref_protected(mpath); 711 if (mpath->flags & MESH_PATH_ACTIVE && 712 compare_ether_addr(ta, sta->sta.addr) == 0 && 713 (!(mpath->flags & MESH_PATH_SN_VALID) || 714 SN_GT(target_sn, mpath->sn))) { 715 mpath->flags &= ~MESH_PATH_ACTIVE; 716 mpath->sn = target_sn; 717 spin_unlock_bh(&mpath->state_lock); 718 if (!ifmsh->mshcfg.dot11MeshForwarding) 719 goto endperr; 720 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn), 721 cpu_to_le16(target_rcode), 722 broadcast_addr, sdata); 723 } else 724 spin_unlock_bh(&mpath->state_lock); 725 } 726 endperr: 727 rcu_read_unlock(); 728 } 729 730 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 731 struct ieee80211_mgmt *mgmt, 732 struct ieee80211_rann_ie *rann) 733 { 734 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 735 struct mesh_path *mpath; 736 u8 ttl, flags, hopcount; 737 u8 *orig_addr; 738 u32 orig_sn, metric; 739 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 740 bool root_is_gate; 741 742 ttl = rann->rann_ttl; 743 if (ttl <= 1) { 744 ifmsh->mshstats.dropped_frames_ttl++; 745 return; 746 } 747 ttl--; 748 flags = rann->rann_flags; 749 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 750 orig_addr = rann->rann_addr; 751 orig_sn = rann->rann_seq; 752 hopcount = rann->rann_hopcount; 753 hopcount++; 754 metric = rann->rann_metric; 755 756 /* Ignore our own RANNs */ 757 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0) 758 return; 759 760 mhwmp_dbg("received RANN from %pM via neighbour %pM (is_gate=%d)", 761 orig_addr, mgmt->sa, root_is_gate); 762 763 rcu_read_lock(); 764 mpath = mesh_path_lookup(orig_addr, sdata); 765 if (!mpath) { 766 mesh_path_add(orig_addr, sdata); 767 mpath = mesh_path_lookup(orig_addr, sdata); 768 if (!mpath) { 769 rcu_read_unlock(); 770 sdata->u.mesh.mshstats.dropped_frames_no_route++; 771 return; 772 } 773 } 774 775 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 776 time_after(jiffies, mpath->exp_time - 1*HZ)) && 777 !(mpath->flags & MESH_PATH_FIXED)) { 778 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name, 779 orig_addr); 780 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 781 } 782 783 if (mpath->sn < orig_sn && ifmsh->mshcfg.dot11MeshForwarding) { 784 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 785 cpu_to_le32(orig_sn), 786 0, NULL, 0, broadcast_addr, 787 hopcount, ttl, cpu_to_le32(interval), 788 cpu_to_le32(metric + mpath->metric), 789 0, sdata); 790 mpath->sn = orig_sn; 791 } 792 793 /* Using individually addressed PREQ for root node */ 794 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); 795 mpath->is_root = true; 796 797 if (root_is_gate) 798 mesh_path_add_gate(mpath); 799 800 rcu_read_unlock(); 801 } 802 803 804 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 805 struct ieee80211_mgmt *mgmt, 806 size_t len) 807 { 808 struct ieee802_11_elems elems; 809 size_t baselen; 810 u32 last_hop_metric; 811 struct sta_info *sta; 812 813 /* need action_code */ 814 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 815 return; 816 817 rcu_read_lock(); 818 sta = sta_info_get(sdata, mgmt->sa); 819 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) { 820 rcu_read_unlock(); 821 return; 822 } 823 rcu_read_unlock(); 824 825 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 826 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 827 len - baselen, &elems); 828 829 if (elems.preq) { 830 if (elems.preq_len != 37) 831 /* Right now we support just 1 destination and no AE */ 832 return; 833 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 834 MPATH_PREQ); 835 if (last_hop_metric) 836 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 837 last_hop_metric); 838 } 839 if (elems.prep) { 840 if (elems.prep_len != 31) 841 /* Right now we support no AE */ 842 return; 843 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 844 MPATH_PREP); 845 if (last_hop_metric) 846 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 847 last_hop_metric); 848 } 849 if (elems.perr) { 850 if (elems.perr_len != 15) 851 /* Right now we support only one destination per PERR */ 852 return; 853 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 854 } 855 if (elems.rann) 856 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 857 } 858 859 /** 860 * mesh_queue_preq - queue a PREQ to a given destination 861 * 862 * @mpath: mesh path to discover 863 * @flags: special attributes of the PREQ to be sent 864 * 865 * Locking: the function must be called from within a rcu read lock block. 866 * 867 */ 868 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 869 { 870 struct ieee80211_sub_if_data *sdata = mpath->sdata; 871 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 872 struct mesh_preq_queue *preq_node; 873 874 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 875 if (!preq_node) { 876 mhwmp_dbg("could not allocate PREQ node"); 877 return; 878 } 879 880 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 881 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 882 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 883 kfree(preq_node); 884 if (printk_ratelimit()) 885 mhwmp_dbg("PREQ node queue full"); 886 return; 887 } 888 889 spin_lock(&mpath->state_lock); 890 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 891 spin_unlock(&mpath->state_lock); 892 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 893 kfree(preq_node); 894 return; 895 } 896 897 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 898 preq_node->flags = flags; 899 900 mpath->flags |= MESH_PATH_REQ_QUEUED; 901 spin_unlock(&mpath->state_lock); 902 903 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 904 ++ifmsh->preq_queue_len; 905 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 906 907 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 908 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 909 910 else if (time_before(jiffies, ifmsh->last_preq)) { 911 /* avoid long wait if did not send preqs for a long time 912 * and jiffies wrapped around 913 */ 914 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 915 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 916 } else 917 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 918 min_preq_int_jiff(sdata)); 919 } 920 921 /** 922 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 923 * 924 * @sdata: local mesh subif 925 */ 926 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 927 { 928 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 929 struct mesh_preq_queue *preq_node; 930 struct mesh_path *mpath; 931 u8 ttl, target_flags; 932 const u8 *da; 933 u32 lifetime; 934 935 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 936 if (!ifmsh->preq_queue_len || 937 time_before(jiffies, ifmsh->last_preq + 938 min_preq_int_jiff(sdata))) { 939 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 940 return; 941 } 942 943 preq_node = list_first_entry(&ifmsh->preq_queue.list, 944 struct mesh_preq_queue, list); 945 list_del(&preq_node->list); 946 --ifmsh->preq_queue_len; 947 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 948 949 rcu_read_lock(); 950 mpath = mesh_path_lookup(preq_node->dst, sdata); 951 if (!mpath) 952 goto enddiscovery; 953 954 spin_lock_bh(&mpath->state_lock); 955 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 956 if (preq_node->flags & PREQ_Q_F_START) { 957 if (mpath->flags & MESH_PATH_RESOLVING) { 958 spin_unlock_bh(&mpath->state_lock); 959 goto enddiscovery; 960 } else { 961 mpath->flags &= ~MESH_PATH_RESOLVED; 962 mpath->flags |= MESH_PATH_RESOLVING; 963 mpath->discovery_retries = 0; 964 mpath->discovery_timeout = disc_timeout_jiff(sdata); 965 } 966 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 967 mpath->flags & MESH_PATH_RESOLVED) { 968 mpath->flags &= ~MESH_PATH_RESOLVING; 969 spin_unlock_bh(&mpath->state_lock); 970 goto enddiscovery; 971 } 972 973 ifmsh->last_preq = jiffies; 974 975 if (time_after(jiffies, ifmsh->last_sn_update + 976 net_traversal_jiffies(sdata)) || 977 time_before(jiffies, ifmsh->last_sn_update)) { 978 ++ifmsh->sn; 979 sdata->u.mesh.last_sn_update = jiffies; 980 } 981 lifetime = default_lifetime(sdata); 982 ttl = sdata->u.mesh.mshcfg.element_ttl; 983 if (ttl == 0) { 984 sdata->u.mesh.mshstats.dropped_frames_ttl++; 985 spin_unlock_bh(&mpath->state_lock); 986 goto enddiscovery; 987 } 988 989 if (preq_node->flags & PREQ_Q_F_REFRESH) 990 target_flags = MP_F_DO; 991 else 992 target_flags = MP_F_RF; 993 994 spin_unlock_bh(&mpath->state_lock); 995 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; 996 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, 997 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst, 998 cpu_to_le32(mpath->sn), da, 0, 999 ttl, cpu_to_le32(lifetime), 0, 1000 cpu_to_le32(ifmsh->preq_id++), sdata); 1001 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 1002 1003 enddiscovery: 1004 rcu_read_unlock(); 1005 kfree(preq_node); 1006 } 1007 1008 /* mesh_nexthop_resolve - lookup next hop for given skb and start path 1009 * discovery if no forwarding information is found. 1010 * 1011 * @skb: 802.11 frame to be sent 1012 * @sdata: network subif the frame will be sent through 1013 * 1014 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 1015 * skb is freeed here if no mpath could be allocated. 1016 */ 1017 int mesh_nexthop_resolve(struct sk_buff *skb, 1018 struct ieee80211_sub_if_data *sdata) 1019 { 1020 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1021 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 1022 struct mesh_path *mpath; 1023 struct sk_buff *skb_to_free = NULL; 1024 u8 *target_addr = hdr->addr3; 1025 int err = 0; 1026 1027 rcu_read_lock(); 1028 err = mesh_nexthop_lookup(skb, sdata); 1029 if (!err) 1030 goto endlookup; 1031 1032 /* no nexthop found, start resolving */ 1033 mpath = mesh_path_lookup(target_addr, sdata); 1034 if (!mpath) { 1035 mesh_path_add(target_addr, sdata); 1036 mpath = mesh_path_lookup(target_addr, sdata); 1037 if (!mpath) { 1038 mesh_path_discard_frame(skb, sdata); 1039 err = -ENOSPC; 1040 goto endlookup; 1041 } 1042 } 1043 1044 if (!(mpath->flags & MESH_PATH_RESOLVING)) 1045 mesh_queue_preq(mpath, PREQ_Q_F_START); 1046 1047 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1048 skb_to_free = skb_dequeue(&mpath->frame_queue); 1049 1050 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 1051 ieee80211_set_qos_hdr(sdata, skb); 1052 skb_queue_tail(&mpath->frame_queue, skb); 1053 err = -ENOENT; 1054 if (skb_to_free) 1055 mesh_path_discard_frame(skb_to_free, sdata); 1056 1057 endlookup: 1058 rcu_read_unlock(); 1059 return err; 1060 } 1061 /** 1062 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1063 * this function is considered "using" the associated mpath, so preempt a path 1064 * refresh if this mpath expires soon. 1065 * 1066 * @skb: 802.11 frame to be sent 1067 * @sdata: network subif the frame will be sent through 1068 * 1069 * Returns: 0 if the next hop was found. Nonzero otherwise. 1070 */ 1071 int mesh_nexthop_lookup(struct sk_buff *skb, 1072 struct ieee80211_sub_if_data *sdata) 1073 { 1074 struct mesh_path *mpath; 1075 struct sta_info *next_hop; 1076 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1077 u8 *target_addr = hdr->addr3; 1078 int err = -ENOENT; 1079 1080 rcu_read_lock(); 1081 mpath = mesh_path_lookup(target_addr, sdata); 1082 1083 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1084 goto endlookup; 1085 1086 if (time_after(jiffies, 1087 mpath->exp_time - 1088 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1089 !compare_ether_addr(sdata->vif.addr, hdr->addr4) && 1090 !(mpath->flags & MESH_PATH_RESOLVING) && 1091 !(mpath->flags & MESH_PATH_FIXED)) 1092 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1093 1094 next_hop = rcu_dereference(mpath->next_hop); 1095 if (next_hop) { 1096 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1097 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1098 err = 0; 1099 } 1100 1101 endlookup: 1102 rcu_read_unlock(); 1103 return err; 1104 } 1105 1106 void mesh_path_timer(unsigned long data) 1107 { 1108 struct mesh_path *mpath = (void *) data; 1109 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1110 int ret; 1111 1112 if (sdata->local->quiescing) 1113 return; 1114 1115 spin_lock_bh(&mpath->state_lock); 1116 if (mpath->flags & MESH_PATH_RESOLVED || 1117 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1118 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1119 spin_unlock_bh(&mpath->state_lock); 1120 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1121 ++mpath->discovery_retries; 1122 mpath->discovery_timeout *= 2; 1123 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1124 spin_unlock_bh(&mpath->state_lock); 1125 mesh_queue_preq(mpath, 0); 1126 } else { 1127 mpath->flags = 0; 1128 mpath->exp_time = jiffies; 1129 spin_unlock_bh(&mpath->state_lock); 1130 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1131 ret = mesh_path_send_to_gates(mpath); 1132 if (ret) 1133 mhwmp_dbg("no gate was reachable"); 1134 } else 1135 mesh_path_flush_pending(mpath); 1136 } 1137 } 1138 1139 void 1140 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1141 { 1142 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1143 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1144 u8 flags; 1145 1146 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1147 ? RANN_FLAG_IS_GATE : 0; 1148 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1149 cpu_to_le32(++ifmsh->sn), 1150 0, NULL, 0, broadcast_addr, 1151 0, sdata->u.mesh.mshcfg.element_ttl, 1152 cpu_to_le32(interval), 0, 0, sdata); 1153 } 1154