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 "wme.h" 12 #include "mesh.h" 13 14 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG 15 #define mhwmp_dbg(fmt, args...) \ 16 printk(KERN_DEBUG "Mesh HWMP (%s): " fmt "\n", sdata->name, ##args) 17 #else 18 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0) 19 #endif 20 21 #define TEST_FRAME_LEN 8192 22 #define MAX_METRIC 0xffffffff 23 #define ARITH_SHIFT 8 24 25 /* Number of frames buffered per destination for unresolved destinations */ 26 #define MESH_FRAME_QUEUE_LEN 10 27 #define MAX_PREQ_QUEUE_LEN 64 28 29 /* Destination only */ 30 #define MP_F_DO 0x1 31 /* Reply and forward */ 32 #define MP_F_RF 0x2 33 /* Unknown Sequence Number */ 34 #define MP_F_USN 0x01 35 /* Reason code Present */ 36 #define MP_F_RCODE 0x02 37 38 static void mesh_queue_preq(struct mesh_path *, u8); 39 40 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae) 41 { 42 if (ae) 43 offset += 6; 44 return get_unaligned_le32(preq_elem + offset); 45 } 46 47 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae) 48 { 49 if (ae) 50 offset += 6; 51 return get_unaligned_le16(preq_elem + offset); 52 } 53 54 /* HWMP IE processing macros */ 55 #define AE_F (1<<6) 56 #define AE_F_SET(x) (*x & AE_F) 57 #define PREQ_IE_FLAGS(x) (*(x)) 58 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 59 #define PREQ_IE_TTL(x) (*(x + 2)) 60 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 61 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 62 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0) 63 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)) 64 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)) 65 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 66 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 67 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)) 68 69 70 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 71 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 72 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 73 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 74 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x)) 75 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)) 76 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)) 77 #define PREP_IE_TARGET_ADDR(x) (x + 3) 78 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 79 80 #define PERR_IE_TTL(x) (*(x)) 81 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 82 #define PERR_IE_TARGET_ADDR(x) (x + 3) 83 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0) 84 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) 85 86 #define MSEC_TO_TU(x) (x*1000/1024) 87 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0) 88 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0) 89 90 #define net_traversal_jiffies(s) \ 91 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 92 #define default_lifetime(s) \ 93 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 94 #define min_preq_int_jiff(s) \ 95 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 96 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 97 #define disc_timeout_jiff(s) \ 98 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 99 100 enum mpath_frame_type { 101 MPATH_PREQ = 0, 102 MPATH_PREP, 103 MPATH_PERR, 104 MPATH_RANN 105 }; 106 107 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 108 109 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 110 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target, 111 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl, 112 __le32 lifetime, __le32 metric, __le32 preq_id, 113 struct ieee80211_sub_if_data *sdata) 114 { 115 struct ieee80211_local *local = sdata->local; 116 struct sk_buff *skb; 117 struct ieee80211_mgmt *mgmt; 118 u8 *pos, ie_len; 119 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + 120 sizeof(mgmt->u.action.u.mesh_action); 121 122 skb = dev_alloc_skb(local->tx_headroom + 123 hdr_len + 124 2 + 37); /* max HWMP IE */ 125 if (!skb) 126 return -1; 127 skb_reserve(skb, local->tx_headroom); 128 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 129 memset(mgmt, 0, hdr_len); 130 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 131 IEEE80211_STYPE_ACTION); 132 133 memcpy(mgmt->da, da, ETH_ALEN); 134 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 135 /* BSSID == SA */ 136 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 137 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 138 mgmt->u.action.u.mesh_action.action_code = 139 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 140 141 switch (action) { 142 case MPATH_PREQ: 143 mhwmp_dbg("sending PREQ to %pM", target); 144 ie_len = 37; 145 pos = skb_put(skb, 2 + ie_len); 146 *pos++ = WLAN_EID_PREQ; 147 break; 148 case MPATH_PREP: 149 mhwmp_dbg("sending PREP to %pM", target); 150 ie_len = 31; 151 pos = skb_put(skb, 2 + ie_len); 152 *pos++ = WLAN_EID_PREP; 153 break; 154 case MPATH_RANN: 155 mhwmp_dbg("sending RANN from %pM", orig_addr); 156 ie_len = sizeof(struct ieee80211_rann_ie); 157 pos = skb_put(skb, 2 + ie_len); 158 *pos++ = WLAN_EID_RANN; 159 break; 160 default: 161 kfree_skb(skb); 162 return -ENOTSUPP; 163 break; 164 } 165 *pos++ = ie_len; 166 *pos++ = flags; 167 *pos++ = hop_count; 168 *pos++ = ttl; 169 if (action == MPATH_PREP) { 170 memcpy(pos, target, ETH_ALEN); 171 pos += ETH_ALEN; 172 memcpy(pos, &target_sn, 4); 173 pos += 4; 174 } else { 175 if (action == MPATH_PREQ) { 176 memcpy(pos, &preq_id, 4); 177 pos += 4; 178 } 179 memcpy(pos, orig_addr, ETH_ALEN); 180 pos += ETH_ALEN; 181 memcpy(pos, &orig_sn, 4); 182 pos += 4; 183 } 184 memcpy(pos, &lifetime, 4); /* interval for RANN */ 185 pos += 4; 186 memcpy(pos, &metric, 4); 187 pos += 4; 188 if (action == MPATH_PREQ) { 189 *pos++ = 1; /* destination count */ 190 *pos++ = target_flags; 191 memcpy(pos, target, ETH_ALEN); 192 pos += ETH_ALEN; 193 memcpy(pos, &target_sn, 4); 194 pos += 4; 195 } else if (action == MPATH_PREP) { 196 memcpy(pos, orig_addr, ETH_ALEN); 197 pos += ETH_ALEN; 198 memcpy(pos, &orig_sn, 4); 199 pos += 4; 200 } 201 202 ieee80211_tx_skb(sdata, skb); 203 return 0; 204 } 205 206 207 /* Headroom is not adjusted. Caller should ensure that skb has sufficient 208 * headroom in case the frame is encrypted. */ 209 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, 210 struct sk_buff *skb) 211 { 212 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 213 214 skb_set_mac_header(skb, 0); 215 skb_set_network_header(skb, 0); 216 skb_set_transport_header(skb, 0); 217 218 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ 219 skb_set_queue_mapping(skb, IEEE80211_AC_VO); 220 skb->priority = 7; 221 222 info->control.vif = &sdata->vif; 223 ieee80211_set_qos_hdr(sdata, skb); 224 } 225 226 /** 227 * mesh_send_path error - Sends a PERR mesh management frame 228 * 229 * @target: broken destination 230 * @target_sn: SN of the broken destination 231 * @target_rcode: reason code for this PERR 232 * @ra: node this frame is addressed to 233 * 234 * Note: This function may be called with driver locks taken that the driver 235 * also acquires in the TX path. To avoid a deadlock we don't transmit the 236 * frame directly but add it to the pending queue instead. 237 */ 238 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, 239 __le16 target_rcode, const u8 *ra, 240 struct ieee80211_sub_if_data *sdata) 241 { 242 struct ieee80211_local *local = sdata->local; 243 struct sk_buff *skb; 244 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 245 struct ieee80211_mgmt *mgmt; 246 u8 *pos, ie_len; 247 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + 248 sizeof(mgmt->u.action.u.mesh_action); 249 250 if (time_before(jiffies, ifmsh->next_perr)) 251 return -EAGAIN; 252 253 skb = dev_alloc_skb(local->tx_headroom + 254 hdr_len + 255 2 + 15 /* PERR IE */); 256 if (!skb) 257 return -1; 258 skb_reserve(skb, local->tx_headroom); 259 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 260 memset(mgmt, 0, hdr_len); 261 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 262 IEEE80211_STYPE_ACTION); 263 264 memcpy(mgmt->da, ra, ETH_ALEN); 265 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 266 /* BSSID == SA */ 267 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 268 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; 269 mgmt->u.action.u.mesh_action.action_code = 270 WLAN_MESH_ACTION_HWMP_PATH_SELECTION; 271 ie_len = 15; 272 pos = skb_put(skb, 2 + ie_len); 273 *pos++ = WLAN_EID_PERR; 274 *pos++ = ie_len; 275 /* ttl */ 276 *pos++ = ttl; 277 /* number of destinations */ 278 *pos++ = 1; 279 /* 280 * flags bit, bit 1 is unset if we know the sequence number and 281 * bit 2 is set if we have a reason code 282 */ 283 *pos = 0; 284 if (!target_sn) 285 *pos |= MP_F_USN; 286 if (target_rcode) 287 *pos |= MP_F_RCODE; 288 pos++; 289 memcpy(pos, target, ETH_ALEN); 290 pos += ETH_ALEN; 291 memcpy(pos, &target_sn, 4); 292 pos += 4; 293 memcpy(pos, &target_rcode, 2); 294 295 /* see note in function header */ 296 prepare_frame_for_deferred_tx(sdata, skb); 297 ifmsh->next_perr = TU_TO_EXP_TIME( 298 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval); 299 ieee80211_add_pending_skb(local, skb); 300 return 0; 301 } 302 303 void ieee80211s_update_metric(struct ieee80211_local *local, 304 struct sta_info *stainfo, struct sk_buff *skb) 305 { 306 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); 307 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 308 int failed; 309 310 if (!ieee80211_is_data(hdr->frame_control)) 311 return; 312 313 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 314 315 /* moving average, scaled to 100 */ 316 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed); 317 if (stainfo->fail_avg > 95) 318 mesh_plink_broken(stainfo); 319 } 320 321 static u32 airtime_link_metric_get(struct ieee80211_local *local, 322 struct sta_info *sta) 323 { 324 struct ieee80211_supported_band *sband; 325 /* This should be adjusted for each device */ 326 int device_constant = 1 << ARITH_SHIFT; 327 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 328 int s_unit = 1 << ARITH_SHIFT; 329 int rate, err; 330 u32 tx_time, estimated_retx; 331 u64 result; 332 333 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 334 335 if (sta->fail_avg >= 100) 336 return MAX_METRIC; 337 338 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS) 339 return MAX_METRIC; 340 341 err = (sta->fail_avg << ARITH_SHIFT) / 100; 342 343 /* bitrate is in units of 100 Kbps, while we need rate in units of 344 * 1Mbps. This will be corrected on tx_time computation. 345 */ 346 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate; 347 tx_time = (device_constant + 10 * test_frame_len / rate); 348 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 349 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 350 return (u32)result; 351 } 352 353 /** 354 * hwmp_route_info_get - Update routing info to originator and transmitter 355 * 356 * @sdata: local mesh subif 357 * @mgmt: mesh management frame 358 * @hwmp_ie: hwmp information element (PREP or PREQ) 359 * 360 * This function updates the path routing information to the originator and the 361 * transmitter of a HWMP PREQ or PREP frame. 362 * 363 * Returns: metric to frame originator or 0 if the frame should not be further 364 * processed 365 * 366 * Notes: this function is the only place (besides user-provided info) where 367 * path routing information is updated. 368 */ 369 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 370 struct ieee80211_mgmt *mgmt, 371 u8 *hwmp_ie, enum mpath_frame_type action) 372 { 373 struct ieee80211_local *local = sdata->local; 374 struct mesh_path *mpath; 375 struct sta_info *sta; 376 bool fresh_info; 377 u8 *orig_addr, *ta; 378 u32 orig_sn, orig_metric; 379 unsigned long orig_lifetime, exp_time; 380 u32 last_hop_metric, new_metric; 381 bool process = true; 382 383 rcu_read_lock(); 384 sta = sta_info_get(sdata, mgmt->sa); 385 if (!sta) { 386 rcu_read_unlock(); 387 return 0; 388 } 389 390 last_hop_metric = airtime_link_metric_get(local, sta); 391 /* Update and check originator routing info */ 392 fresh_info = true; 393 394 switch (action) { 395 case MPATH_PREQ: 396 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 397 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 398 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 399 orig_metric = PREQ_IE_METRIC(hwmp_ie); 400 break; 401 case MPATH_PREP: 402 /* Originator here refers to the MP that was the target in the 403 * Path Request. We divert from the nomenclature in the draft 404 * so that we can easily use a single function to gather path 405 * information from both PREQ and PREP frames. 406 */ 407 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie); 408 orig_sn = PREP_IE_TARGET_SN(hwmp_ie); 409 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 410 orig_metric = PREP_IE_METRIC(hwmp_ie); 411 break; 412 default: 413 rcu_read_unlock(); 414 return 0; 415 } 416 new_metric = orig_metric + last_hop_metric; 417 if (new_metric < orig_metric) 418 new_metric = MAX_METRIC; 419 exp_time = TU_TO_EXP_TIME(orig_lifetime); 420 421 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) { 422 /* This MP is the originator, we are not interested in this 423 * frame, except for updating transmitter's path info. 424 */ 425 process = false; 426 fresh_info = false; 427 } else { 428 mpath = mesh_path_lookup(orig_addr, sdata); 429 if (mpath) { 430 spin_lock_bh(&mpath->state_lock); 431 if (mpath->flags & MESH_PATH_FIXED) 432 fresh_info = false; 433 else if ((mpath->flags & MESH_PATH_ACTIVE) && 434 (mpath->flags & MESH_PATH_SN_VALID)) { 435 if (SN_GT(mpath->sn, orig_sn) || 436 (mpath->sn == orig_sn && 437 new_metric >= mpath->metric)) { 438 process = false; 439 fresh_info = false; 440 } 441 } 442 } else { 443 mesh_path_add(orig_addr, sdata); 444 mpath = mesh_path_lookup(orig_addr, sdata); 445 if (!mpath) { 446 rcu_read_unlock(); 447 return 0; 448 } 449 spin_lock_bh(&mpath->state_lock); 450 } 451 452 if (fresh_info) { 453 mesh_path_assign_nexthop(mpath, sta); 454 mpath->flags |= MESH_PATH_SN_VALID; 455 mpath->metric = new_metric; 456 mpath->sn = orig_sn; 457 mpath->exp_time = time_after(mpath->exp_time, exp_time) 458 ? mpath->exp_time : exp_time; 459 mesh_path_activate(mpath); 460 spin_unlock_bh(&mpath->state_lock); 461 mesh_path_tx_pending(mpath); 462 /* draft says preq_id should be saved to, but there does 463 * not seem to be any use for it, skipping by now 464 */ 465 } else 466 spin_unlock_bh(&mpath->state_lock); 467 } 468 469 /* Update and check transmitter routing info */ 470 ta = mgmt->sa; 471 if (memcmp(orig_addr, ta, ETH_ALEN) == 0) 472 fresh_info = false; 473 else { 474 fresh_info = true; 475 476 mpath = mesh_path_lookup(ta, sdata); 477 if (mpath) { 478 spin_lock_bh(&mpath->state_lock); 479 if ((mpath->flags & MESH_PATH_FIXED) || 480 ((mpath->flags & MESH_PATH_ACTIVE) && 481 (last_hop_metric > mpath->metric))) 482 fresh_info = false; 483 } else { 484 mesh_path_add(ta, sdata); 485 mpath = mesh_path_lookup(ta, sdata); 486 if (!mpath) { 487 rcu_read_unlock(); 488 return 0; 489 } 490 spin_lock_bh(&mpath->state_lock); 491 } 492 493 if (fresh_info) { 494 mesh_path_assign_nexthop(mpath, sta); 495 mpath->metric = last_hop_metric; 496 mpath->exp_time = time_after(mpath->exp_time, exp_time) 497 ? mpath->exp_time : exp_time; 498 mesh_path_activate(mpath); 499 spin_unlock_bh(&mpath->state_lock); 500 mesh_path_tx_pending(mpath); 501 } else 502 spin_unlock_bh(&mpath->state_lock); 503 } 504 505 rcu_read_unlock(); 506 507 return process ? new_metric : 0; 508 } 509 510 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 511 struct ieee80211_mgmt *mgmt, 512 u8 *preq_elem, u32 metric) 513 { 514 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 515 struct mesh_path *mpath; 516 u8 *target_addr, *orig_addr; 517 u8 target_flags, ttl; 518 u32 orig_sn, target_sn, lifetime; 519 bool reply = false; 520 bool forward = true; 521 522 /* Update target SN, if present */ 523 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 524 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 525 target_sn = PREQ_IE_TARGET_SN(preq_elem); 526 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 527 target_flags = PREQ_IE_TARGET_F(preq_elem); 528 529 mhwmp_dbg("received PREQ from %pM", orig_addr); 530 531 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) { 532 mhwmp_dbg("PREQ is for us"); 533 forward = false; 534 reply = true; 535 metric = 0; 536 if (time_after(jiffies, ifmsh->last_sn_update + 537 net_traversal_jiffies(sdata)) || 538 time_before(jiffies, ifmsh->last_sn_update)) { 539 target_sn = ++ifmsh->sn; 540 ifmsh->last_sn_update = jiffies; 541 } 542 } else { 543 rcu_read_lock(); 544 mpath = mesh_path_lookup(target_addr, sdata); 545 if (mpath) { 546 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 547 SN_LT(mpath->sn, target_sn)) { 548 mpath->sn = target_sn; 549 mpath->flags |= MESH_PATH_SN_VALID; 550 } else if ((!(target_flags & MP_F_DO)) && 551 (mpath->flags & MESH_PATH_ACTIVE)) { 552 reply = true; 553 metric = mpath->metric; 554 target_sn = mpath->sn; 555 if (target_flags & MP_F_RF) 556 target_flags |= MP_F_DO; 557 else 558 forward = false; 559 } 560 } 561 rcu_read_unlock(); 562 } 563 564 if (reply) { 565 lifetime = PREQ_IE_LIFETIME(preq_elem); 566 ttl = ifmsh->mshcfg.element_ttl; 567 if (ttl != 0) { 568 mhwmp_dbg("replying to the PREQ"); 569 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, 570 cpu_to_le32(orig_sn), 0, target_addr, 571 cpu_to_le32(target_sn), mgmt->sa, 0, ttl, 572 cpu_to_le32(lifetime), cpu_to_le32(metric), 573 0, sdata); 574 } else 575 ifmsh->mshstats.dropped_frames_ttl++; 576 } 577 578 if (forward) { 579 u32 preq_id; 580 u8 hopcount, flags; 581 582 ttl = PREQ_IE_TTL(preq_elem); 583 lifetime = PREQ_IE_LIFETIME(preq_elem); 584 if (ttl <= 1) { 585 ifmsh->mshstats.dropped_frames_ttl++; 586 return; 587 } 588 mhwmp_dbg("forwarding the PREQ from %pM", orig_addr); 589 --ttl; 590 flags = PREQ_IE_FLAGS(preq_elem); 591 preq_id = PREQ_IE_PREQ_ID(preq_elem); 592 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 593 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 594 cpu_to_le32(orig_sn), target_flags, target_addr, 595 cpu_to_le32(target_sn), broadcast_addr, 596 hopcount, ttl, cpu_to_le32(lifetime), 597 cpu_to_le32(metric), cpu_to_le32(preq_id), 598 sdata); 599 ifmsh->mshstats.fwded_mcast++; 600 ifmsh->mshstats.fwded_frames++; 601 } 602 } 603 604 605 static inline struct sta_info * 606 next_hop_deref_protected(struct mesh_path *mpath) 607 { 608 return rcu_dereference_protected(mpath->next_hop, 609 lockdep_is_held(&mpath->state_lock)); 610 } 611 612 613 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 614 struct ieee80211_mgmt *mgmt, 615 u8 *prep_elem, u32 metric) 616 { 617 struct mesh_path *mpath; 618 u8 *target_addr, *orig_addr; 619 u8 ttl, hopcount, flags; 620 u8 next_hop[ETH_ALEN]; 621 u32 target_sn, orig_sn, lifetime; 622 623 mhwmp_dbg("received PREP from %pM", PREP_IE_ORIG_ADDR(prep_elem)); 624 625 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 626 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) 627 /* destination, no forwarding required */ 628 return; 629 630 ttl = PREP_IE_TTL(prep_elem); 631 if (ttl <= 1) { 632 sdata->u.mesh.mshstats.dropped_frames_ttl++; 633 return; 634 } 635 636 rcu_read_lock(); 637 mpath = mesh_path_lookup(orig_addr, sdata); 638 if (mpath) 639 spin_lock_bh(&mpath->state_lock); 640 else 641 goto fail; 642 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 643 spin_unlock_bh(&mpath->state_lock); 644 goto fail; 645 } 646 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 647 spin_unlock_bh(&mpath->state_lock); 648 --ttl; 649 flags = PREP_IE_FLAGS(prep_elem); 650 lifetime = PREP_IE_LIFETIME(prep_elem); 651 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 652 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 653 target_sn = PREP_IE_TARGET_SN(prep_elem); 654 orig_sn = PREP_IE_ORIG_SN(prep_elem); 655 656 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 657 cpu_to_le32(orig_sn), 0, target_addr, 658 cpu_to_le32(target_sn), next_hop, hopcount, 659 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric), 660 0, sdata); 661 rcu_read_unlock(); 662 663 sdata->u.mesh.mshstats.fwded_unicast++; 664 sdata->u.mesh.mshstats.fwded_frames++; 665 return; 666 667 fail: 668 rcu_read_unlock(); 669 sdata->u.mesh.mshstats.dropped_frames_no_route++; 670 } 671 672 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 673 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 674 { 675 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 676 struct mesh_path *mpath; 677 u8 ttl; 678 u8 *ta, *target_addr; 679 u32 target_sn; 680 u16 target_rcode; 681 682 ta = mgmt->sa; 683 ttl = PERR_IE_TTL(perr_elem); 684 if (ttl <= 1) { 685 ifmsh->mshstats.dropped_frames_ttl++; 686 return; 687 } 688 ttl--; 689 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 690 target_sn = PERR_IE_TARGET_SN(perr_elem); 691 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 692 693 rcu_read_lock(); 694 mpath = mesh_path_lookup(target_addr, sdata); 695 if (mpath) { 696 spin_lock_bh(&mpath->state_lock); 697 if (mpath->flags & MESH_PATH_ACTIVE && 698 memcmp(ta, next_hop_deref_protected(mpath)->sta.addr, 699 ETH_ALEN) == 0 && 700 (!(mpath->flags & MESH_PATH_SN_VALID) || 701 SN_GT(target_sn, mpath->sn))) { 702 mpath->flags &= ~MESH_PATH_ACTIVE; 703 mpath->sn = target_sn; 704 spin_unlock_bh(&mpath->state_lock); 705 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn), 706 cpu_to_le16(target_rcode), 707 broadcast_addr, sdata); 708 } else 709 spin_unlock_bh(&mpath->state_lock); 710 } 711 rcu_read_unlock(); 712 } 713 714 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 715 struct ieee80211_mgmt *mgmt, 716 struct ieee80211_rann_ie *rann) 717 { 718 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 719 struct mesh_path *mpath; 720 u8 ttl, flags, hopcount; 721 u8 *orig_addr; 722 u32 orig_sn, metric; 723 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 724 bool root_is_gate; 725 726 ttl = rann->rann_ttl; 727 if (ttl <= 1) { 728 ifmsh->mshstats.dropped_frames_ttl++; 729 return; 730 } 731 ttl--; 732 flags = rann->rann_flags; 733 root_is_gate = !!(flags & RANN_FLAG_IS_GATE); 734 orig_addr = rann->rann_addr; 735 orig_sn = rann->rann_seq; 736 hopcount = rann->rann_hopcount; 737 hopcount++; 738 metric = rann->rann_metric; 739 740 /* Ignore our own RANNs */ 741 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) 742 return; 743 744 mhwmp_dbg("received RANN from %pM (is_gate=%d)", orig_addr, 745 root_is_gate); 746 747 rcu_read_lock(); 748 mpath = mesh_path_lookup(orig_addr, sdata); 749 if (!mpath) { 750 mesh_path_add(orig_addr, sdata); 751 mpath = mesh_path_lookup(orig_addr, sdata); 752 if (!mpath) { 753 rcu_read_unlock(); 754 sdata->u.mesh.mshstats.dropped_frames_no_route++; 755 return; 756 } 757 } 758 759 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || 760 time_after(jiffies, mpath->exp_time - 1*HZ)) && 761 !(mpath->flags & MESH_PATH_FIXED)) { 762 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name, 763 orig_addr); 764 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 765 } 766 767 if (mpath->sn < orig_sn) { 768 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 769 cpu_to_le32(orig_sn), 770 0, NULL, 0, broadcast_addr, 771 hopcount, ttl, cpu_to_le32(interval), 772 cpu_to_le32(metric + mpath->metric), 773 0, sdata); 774 mpath->sn = orig_sn; 775 } 776 if (root_is_gate) 777 mesh_path_add_gate(mpath); 778 779 rcu_read_unlock(); 780 } 781 782 783 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 784 struct ieee80211_mgmt *mgmt, 785 size_t len) 786 { 787 struct ieee802_11_elems elems; 788 size_t baselen; 789 u32 last_hop_metric; 790 struct sta_info *sta; 791 792 /* need action_code */ 793 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 794 return; 795 796 rcu_read_lock(); 797 sta = sta_info_get(sdata, mgmt->sa); 798 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) { 799 rcu_read_unlock(); 800 return; 801 } 802 rcu_read_unlock(); 803 804 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 805 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 806 len - baselen, &elems); 807 808 if (elems.preq) { 809 if (elems.preq_len != 37) 810 /* Right now we support just 1 destination and no AE */ 811 return; 812 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 813 MPATH_PREQ); 814 if (last_hop_metric) 815 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 816 last_hop_metric); 817 } 818 if (elems.prep) { 819 if (elems.prep_len != 31) 820 /* Right now we support no AE */ 821 return; 822 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 823 MPATH_PREP); 824 if (last_hop_metric) 825 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 826 last_hop_metric); 827 } 828 if (elems.perr) { 829 if (elems.perr_len != 15) 830 /* Right now we support only one destination per PERR */ 831 return; 832 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 833 } 834 if (elems.rann) 835 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 836 } 837 838 /** 839 * mesh_queue_preq - queue a PREQ to a given destination 840 * 841 * @mpath: mesh path to discover 842 * @flags: special attributes of the PREQ to be sent 843 * 844 * Locking: the function must be called from within a rcu read lock block. 845 * 846 */ 847 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 848 { 849 struct ieee80211_sub_if_data *sdata = mpath->sdata; 850 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 851 struct mesh_preq_queue *preq_node; 852 853 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 854 if (!preq_node) { 855 mhwmp_dbg("could not allocate PREQ node"); 856 return; 857 } 858 859 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 860 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 861 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 862 kfree(preq_node); 863 if (printk_ratelimit()) 864 mhwmp_dbg("PREQ node queue full"); 865 return; 866 } 867 868 spin_lock(&mpath->state_lock); 869 if (mpath->flags & MESH_PATH_REQ_QUEUED) { 870 spin_unlock(&mpath->state_lock); 871 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 872 kfree(preq_node); 873 return; 874 } 875 876 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 877 preq_node->flags = flags; 878 879 mpath->flags |= MESH_PATH_REQ_QUEUED; 880 spin_unlock(&mpath->state_lock); 881 882 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 883 ++ifmsh->preq_queue_len; 884 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 885 886 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 887 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 888 889 else if (time_before(jiffies, ifmsh->last_preq)) { 890 /* avoid long wait if did not send preqs for a long time 891 * and jiffies wrapped around 892 */ 893 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 894 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 895 } else 896 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 897 min_preq_int_jiff(sdata)); 898 } 899 900 /** 901 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 902 * 903 * @sdata: local mesh subif 904 */ 905 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 906 { 907 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 908 struct mesh_preq_queue *preq_node; 909 struct mesh_path *mpath; 910 u8 ttl, target_flags; 911 u32 lifetime; 912 913 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 914 if (!ifmsh->preq_queue_len || 915 time_before(jiffies, ifmsh->last_preq + 916 min_preq_int_jiff(sdata))) { 917 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 918 return; 919 } 920 921 preq_node = list_first_entry(&ifmsh->preq_queue.list, 922 struct mesh_preq_queue, list); 923 list_del(&preq_node->list); 924 --ifmsh->preq_queue_len; 925 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 926 927 rcu_read_lock(); 928 mpath = mesh_path_lookup(preq_node->dst, sdata); 929 if (!mpath) 930 goto enddiscovery; 931 932 spin_lock_bh(&mpath->state_lock); 933 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 934 if (preq_node->flags & PREQ_Q_F_START) { 935 if (mpath->flags & MESH_PATH_RESOLVING) { 936 spin_unlock_bh(&mpath->state_lock); 937 goto enddiscovery; 938 } else { 939 mpath->flags &= ~MESH_PATH_RESOLVED; 940 mpath->flags |= MESH_PATH_RESOLVING; 941 mpath->discovery_retries = 0; 942 mpath->discovery_timeout = disc_timeout_jiff(sdata); 943 } 944 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 945 mpath->flags & MESH_PATH_RESOLVED) { 946 mpath->flags &= ~MESH_PATH_RESOLVING; 947 spin_unlock_bh(&mpath->state_lock); 948 goto enddiscovery; 949 } 950 951 ifmsh->last_preq = jiffies; 952 953 if (time_after(jiffies, ifmsh->last_sn_update + 954 net_traversal_jiffies(sdata)) || 955 time_before(jiffies, ifmsh->last_sn_update)) { 956 ++ifmsh->sn; 957 sdata->u.mesh.last_sn_update = jiffies; 958 } 959 lifetime = default_lifetime(sdata); 960 ttl = sdata->u.mesh.mshcfg.element_ttl; 961 if (ttl == 0) { 962 sdata->u.mesh.mshstats.dropped_frames_ttl++; 963 spin_unlock_bh(&mpath->state_lock); 964 goto enddiscovery; 965 } 966 967 if (preq_node->flags & PREQ_Q_F_REFRESH) 968 target_flags = MP_F_DO; 969 else 970 target_flags = MP_F_RF; 971 972 spin_unlock_bh(&mpath->state_lock); 973 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, 974 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst, 975 cpu_to_le32(mpath->sn), broadcast_addr, 0, 976 ttl, cpu_to_le32(lifetime), 0, 977 cpu_to_le32(ifmsh->preq_id++), sdata); 978 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 979 980 enddiscovery: 981 rcu_read_unlock(); 982 kfree(preq_node); 983 } 984 985 /* mesh_nexthop_resolve - lookup next hop for given skb and start path 986 * discovery if no forwarding information is found. 987 * 988 * @skb: 802.11 frame to be sent 989 * @sdata: network subif the frame will be sent through 990 * 991 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. 992 * skb is freeed here if no mpath could be allocated. 993 */ 994 int mesh_nexthop_resolve(struct sk_buff *skb, 995 struct ieee80211_sub_if_data *sdata) 996 { 997 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 998 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 999 struct mesh_path *mpath; 1000 struct sk_buff *skb_to_free = NULL; 1001 u8 *target_addr = hdr->addr3; 1002 int err = 0; 1003 1004 rcu_read_lock(); 1005 err = mesh_nexthop_lookup(skb, sdata); 1006 if (!err) 1007 goto endlookup; 1008 1009 /* no nexthop found, start resolving */ 1010 mpath = mesh_path_lookup(target_addr, sdata); 1011 if (!mpath) { 1012 mesh_path_add(target_addr, sdata); 1013 mpath = mesh_path_lookup(target_addr, sdata); 1014 if (!mpath) { 1015 mesh_path_discard_frame(skb, sdata); 1016 err = -ENOSPC; 1017 goto endlookup; 1018 } 1019 } 1020 1021 if (!(mpath->flags & MESH_PATH_RESOLVING)) 1022 mesh_queue_preq(mpath, PREQ_Q_F_START); 1023 1024 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) 1025 skb_to_free = skb_dequeue(&mpath->frame_queue); 1026 1027 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 1028 ieee80211_set_qos_hdr(sdata, skb); 1029 skb_queue_tail(&mpath->frame_queue, skb); 1030 err = -ENOENT; 1031 if (skb_to_free) 1032 mesh_path_discard_frame(skb_to_free, sdata); 1033 1034 endlookup: 1035 rcu_read_unlock(); 1036 return err; 1037 } 1038 /** 1039 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling 1040 * this function is considered "using" the associated mpath, so preempt a path 1041 * refresh if this mpath expires soon. 1042 * 1043 * @skb: 802.11 frame to be sent 1044 * @sdata: network subif the frame will be sent through 1045 * 1046 * Returns: 0 if the next hop was found. Nonzero otherwise. 1047 */ 1048 int mesh_nexthop_lookup(struct sk_buff *skb, 1049 struct ieee80211_sub_if_data *sdata) 1050 { 1051 struct mesh_path *mpath; 1052 struct sta_info *next_hop; 1053 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1054 u8 *target_addr = hdr->addr3; 1055 int err = -ENOENT; 1056 1057 rcu_read_lock(); 1058 mpath = mesh_path_lookup(target_addr, sdata); 1059 1060 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) 1061 goto endlookup; 1062 1063 if (time_after(jiffies, 1064 mpath->exp_time - 1065 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 1066 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) && 1067 !(mpath->flags & MESH_PATH_RESOLVING) && 1068 !(mpath->flags & MESH_PATH_FIXED)) 1069 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); 1070 1071 next_hop = rcu_dereference(mpath->next_hop); 1072 if (next_hop) { 1073 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 1074 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); 1075 err = 0; 1076 } 1077 1078 endlookup: 1079 rcu_read_unlock(); 1080 return err; 1081 } 1082 1083 void mesh_path_timer(unsigned long data) 1084 { 1085 struct mesh_path *mpath = (void *) data; 1086 struct ieee80211_sub_if_data *sdata = mpath->sdata; 1087 int ret; 1088 1089 if (sdata->local->quiescing) 1090 return; 1091 1092 spin_lock_bh(&mpath->state_lock); 1093 if (mpath->flags & MESH_PATH_RESOLVED || 1094 (!(mpath->flags & MESH_PATH_RESOLVING))) { 1095 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 1096 spin_unlock_bh(&mpath->state_lock); 1097 } else if (mpath->discovery_retries < max_preq_retries(sdata)) { 1098 ++mpath->discovery_retries; 1099 mpath->discovery_timeout *= 2; 1100 mpath->flags &= ~MESH_PATH_REQ_QUEUED; 1101 spin_unlock_bh(&mpath->state_lock); 1102 mesh_queue_preq(mpath, 0); 1103 } else { 1104 mpath->flags = 0; 1105 mpath->exp_time = jiffies; 1106 spin_unlock_bh(&mpath->state_lock); 1107 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { 1108 ret = mesh_path_send_to_gates(mpath); 1109 if (ret) 1110 mhwmp_dbg("no gate was reachable"); 1111 } else 1112 mesh_path_flush_pending(mpath); 1113 } 1114 } 1115 1116 void 1117 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1118 { 1119 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1120 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; 1121 u8 flags; 1122 1123 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) 1124 ? RANN_FLAG_IS_GATE : 0; 1125 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, 1126 cpu_to_le32(++ifmsh->sn), 1127 0, NULL, 0, broadcast_addr, 1128 0, sdata->u.mesh.mshcfg.element_ttl, 1129 cpu_to_le32(interval), 0, 0, sdata); 1130 } 1131