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 "mesh.h" 12 13#ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG 14#define mhwmp_dbg(fmt, args...) printk(KERN_DEBUG "Mesh HWMP: " fmt, ##args) 15#else 16#define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0) 17#endif 18 19#define TEST_FRAME_LEN 8192 20#define MAX_METRIC 0xffffffff 21#define ARITH_SHIFT 8 22 23/* Number of frames buffered per destination for unresolved destinations */ 24#define MESH_FRAME_QUEUE_LEN 10 25#define MAX_PREQ_QUEUE_LEN 64 26 27/* Destination only */ 28#define MP_F_DO 0x1 29/* Reply and forward */ 30#define MP_F_RF 0x2 31/* Unknown Sequence Number */ 32#define MP_F_USN 0x01 33/* Reason code Present */ 34#define MP_F_RCODE 0x02 35 36static void mesh_queue_preq(struct mesh_path *, u8); 37 38static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae) 39{ 40 if (ae) 41 offset += 6; 42 return get_unaligned_le32(preq_elem + offset); 43} 44 45static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae) 46{ 47 if (ae) 48 offset += 6; 49 return get_unaligned_le16(preq_elem + offset); 50} 51 52/* HWMP IE processing macros */ 53#define AE_F (1<<6) 54#define AE_F_SET(x) (*x & AE_F) 55#define PREQ_IE_FLAGS(x) (*(x)) 56#define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 57#define PREQ_IE_TTL(x) (*(x + 2)) 58#define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 59#define PREQ_IE_ORIG_ADDR(x) (x + 7) 60#define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0); 61#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)); 62#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)); 63#define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 64#define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 65#define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)); 66 67 68#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 69#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 70#define PREP_IE_TTL(x) PREQ_IE_TTL(x) 71#define PREP_IE_ORIG_ADDR(x) (x + 3) 72#define PREP_IE_ORIG_SN(x) u32_field_get(x, 9, 0); 73#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)); 74#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)); 75#define PREP_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 76#define PREP_IE_TARGET_SN(x) u32_field_get(x, 27, AE_F_SET(x)); 77 78#define PERR_IE_TTL(x) (*(x)) 79#define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 80#define PERR_IE_TARGET_ADDR(x) (x + 3) 81#define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0); 82#define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0); 83 84#define MSEC_TO_TU(x) (x*1000/1024) 85#define SN_GT(x, y) ((long) (y) - (long) (x) < 0) 86#define SN_LT(x, y) ((long) (x) - (long) (y) < 0) 87 88#define net_traversal_jiffies(s) \ 89 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 90#define default_lifetime(s) \ 91 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 92#define min_preq_int_jiff(s) \ 93 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 94#define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 95#define disc_timeout_jiff(s) \ 96 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 97 98enum mpath_frame_type { 99 MPATH_PREQ = 0, 100 MPATH_PREP, 101 MPATH_PERR, 102 MPATH_RANN 103}; 104 105static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 106 107static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 108 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target, 109 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl, 110 __le32 lifetime, __le32 metric, __le32 preq_id, 111 struct ieee80211_sub_if_data *sdata) 112{ 113 struct ieee80211_local *local = sdata->local; 114 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 115 struct ieee80211_mgmt *mgmt; 116 u8 *pos; 117 int ie_len; 118 119 if (!skb) 120 return -1; 121 skb_reserve(skb, local->hw.extra_tx_headroom); 122 /* 25 is the size of the common mgmt part (24) plus the size of the 123 * common action part (1) 124 */ 125 mgmt = (struct ieee80211_mgmt *) 126 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 127 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 128 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 129 IEEE80211_STYPE_ACTION); 130 131 memcpy(mgmt->da, da, ETH_ALEN); 132 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 133 /* BSSID == SA */ 134 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 135 mgmt->u.action.category = WLAN_CATEGORY_MESH_PATH_SEL; 136 mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION; 137 138 switch (action) { 139 case MPATH_PREQ: 140 mhwmp_dbg("sending PREQ to %pM\n", target); 141 ie_len = 37; 142 pos = skb_put(skb, 2 + ie_len); 143 *pos++ = WLAN_EID_PREQ; 144 break; 145 case MPATH_PREP: 146 mhwmp_dbg("sending PREP to %pM\n", target); 147 ie_len = 31; 148 pos = skb_put(skb, 2 + ie_len); 149 *pos++ = WLAN_EID_PREP; 150 break; 151 case MPATH_RANN: 152 mhwmp_dbg("sending RANN from %pM\n", orig_addr); 153 ie_len = sizeof(struct ieee80211_rann_ie); 154 pos = skb_put(skb, 2 + ie_len); 155 *pos++ = WLAN_EID_RANN; 156 break; 157 default: 158 kfree_skb(skb); 159 return -ENOTSUPP; 160 break; 161 } 162 *pos++ = ie_len; 163 *pos++ = flags; 164 *pos++ = hop_count; 165 *pos++ = ttl; 166 if (action == MPATH_PREQ) { 167 memcpy(pos, &preq_id, 4); 168 pos += 4; 169 } 170 memcpy(pos, orig_addr, ETH_ALEN); 171 pos += ETH_ALEN; 172 memcpy(pos, &orig_sn, 4); 173 pos += 4; 174 if (action != MPATH_RANN) { 175 memcpy(pos, &lifetime, 4); 176 pos += 4; 177 } 178 memcpy(pos, &metric, 4); 179 pos += 4; 180 if (action == MPATH_PREQ) { 181 /* destination count */ 182 *pos++ = 1; 183 *pos++ = target_flags; 184 } 185 if (action != MPATH_RANN) { 186 memcpy(pos, target, ETH_ALEN); 187 pos += ETH_ALEN; 188 memcpy(pos, &target_sn, 4); 189 } 190 191 ieee80211_tx_skb(sdata, skb); 192 return 0; 193} 194 195/** 196 * mesh_send_path error - Sends a PERR mesh management frame 197 * 198 * @target: broken destination 199 * @target_sn: SN of the broken destination 200 * @target_rcode: reason code for this PERR 201 * @ra: node this frame is addressed to 202 */ 203int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, 204 __le16 target_rcode, const u8 *ra, 205 struct ieee80211_sub_if_data *sdata) 206{ 207 struct ieee80211_local *local = sdata->local; 208 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 209 struct ieee80211_mgmt *mgmt; 210 u8 *pos; 211 int ie_len; 212 213 if (!skb) 214 return -1; 215 skb_reserve(skb, local->hw.extra_tx_headroom); 216 /* 25 is the size of the common mgmt part (24) plus the size of the 217 * common action part (1) 218 */ 219 mgmt = (struct ieee80211_mgmt *) 220 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 221 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 222 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 223 IEEE80211_STYPE_ACTION); 224 225 memcpy(mgmt->da, ra, ETH_ALEN); 226 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 227 /* BSSID is left zeroed, wildcard value */ 228 mgmt->u.action.category = WLAN_CATEGORY_MESH_PATH_SEL; 229 mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION; 230 ie_len = 15; 231 pos = skb_put(skb, 2 + ie_len); 232 *pos++ = WLAN_EID_PERR; 233 *pos++ = ie_len; 234 /* ttl */ 235 *pos++ = MESH_TTL; 236 /* number of destinations */ 237 *pos++ = 1; 238 /* 239 * flags bit, bit 1 is unset if we know the sequence number and 240 * bit 2 is set if we have a reason code 241 */ 242 *pos = 0; 243 if (!target_sn) 244 *pos |= MP_F_USN; 245 if (target_rcode) 246 *pos |= MP_F_RCODE; 247 pos++; 248 memcpy(pos, target, ETH_ALEN); 249 pos += ETH_ALEN; 250 memcpy(pos, &target_sn, 4); 251 pos += 4; 252 memcpy(pos, &target_rcode, 2); 253 254 ieee80211_tx_skb(sdata, skb); 255 return 0; 256} 257 258void ieee80211s_update_metric(struct ieee80211_local *local, 259 struct sta_info *stainfo, struct sk_buff *skb) 260{ 261 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); 262 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 263 int failed; 264 265 if (!ieee80211_is_data(hdr->frame_control)) 266 return; 267 268 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 269 270 /* moving average, scaled to 100 */ 271 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed); 272 if (stainfo->fail_avg > 95) 273 mesh_plink_broken(stainfo); 274} 275 276static u32 airtime_link_metric_get(struct ieee80211_local *local, 277 struct sta_info *sta) 278{ 279 struct ieee80211_supported_band *sband; 280 /* This should be adjusted for each device */ 281 int device_constant = 1 << ARITH_SHIFT; 282 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 283 int s_unit = 1 << ARITH_SHIFT; 284 int rate, err; 285 u32 tx_time, estimated_retx; 286 u64 result; 287 288 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 289 290 if (sta->fail_avg >= 100) 291 return MAX_METRIC; 292 293 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS) 294 return MAX_METRIC; 295 296 err = (sta->fail_avg << ARITH_SHIFT) / 100; 297 298 /* bitrate is in units of 100 Kbps, while we need rate in units of 299 * 1Mbps. This will be corrected on tx_time computation. 300 */ 301 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate; 302 tx_time = (device_constant + 10 * test_frame_len / rate); 303 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 304 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 305 return (u32)result; 306} 307 308/** 309 * hwmp_route_info_get - Update routing info to originator and transmitter 310 * 311 * @sdata: local mesh subif 312 * @mgmt: mesh management frame 313 * @hwmp_ie: hwmp information element (PREP or PREQ) 314 * 315 * This function updates the path routing information to the originator and the 316 * transmitter of a HWMP PREQ or PREP frame. 317 * 318 * Returns: metric to frame originator or 0 if the frame should not be further 319 * processed 320 * 321 * Notes: this function is the only place (besides user-provided info) where 322 * path routing information is updated. 323 */ 324static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 325 struct ieee80211_mgmt *mgmt, 326 u8 *hwmp_ie, enum mpath_frame_type action) 327{ 328 struct ieee80211_local *local = sdata->local; 329 struct mesh_path *mpath; 330 struct sta_info *sta; 331 bool fresh_info; 332 u8 *orig_addr, *ta; 333 u32 orig_sn, orig_metric; 334 unsigned long orig_lifetime, exp_time; 335 u32 last_hop_metric, new_metric; 336 bool process = true; 337 338 rcu_read_lock(); 339 sta = sta_info_get(sdata, mgmt->sa); 340 if (!sta) { 341 rcu_read_unlock(); 342 return 0; 343 } 344 345 last_hop_metric = airtime_link_metric_get(local, sta); 346 /* Update and check originator routing info */ 347 fresh_info = true; 348 349 switch (action) { 350 case MPATH_PREQ: 351 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 352 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 353 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 354 orig_metric = PREQ_IE_METRIC(hwmp_ie); 355 break; 356 case MPATH_PREP: 357 /* Originator here refers to the MP that was the destination in 358 * the Path Request. The draft refers to that MP as the 359 * destination address, even though usually it is the origin of 360 * the PREP frame. We divert from the nomenclature in the draft 361 * so that we can easily use a single function to gather path 362 * information from both PREQ and PREP frames. 363 */ 364 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie); 365 orig_sn = PREP_IE_ORIG_SN(hwmp_ie); 366 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 367 orig_metric = PREP_IE_METRIC(hwmp_ie); 368 break; 369 default: 370 rcu_read_unlock(); 371 return 0; 372 } 373 new_metric = orig_metric + last_hop_metric; 374 if (new_metric < orig_metric) 375 new_metric = MAX_METRIC; 376 exp_time = TU_TO_EXP_TIME(orig_lifetime); 377 378 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) { 379 /* This MP is the originator, we are not interested in this 380 * frame, except for updating transmitter's path info. 381 */ 382 process = false; 383 fresh_info = false; 384 } else { 385 mpath = mesh_path_lookup(orig_addr, sdata); 386 if (mpath) { 387 spin_lock_bh(&mpath->state_lock); 388 if (mpath->flags & MESH_PATH_FIXED) 389 fresh_info = false; 390 else if ((mpath->flags & MESH_PATH_ACTIVE) && 391 (mpath->flags & MESH_PATH_SN_VALID)) { 392 if (SN_GT(mpath->sn, orig_sn) || 393 (mpath->sn == orig_sn && 394 action == MPATH_PREQ && 395 new_metric >= mpath->metric)) { 396 process = false; 397 fresh_info = false; 398 } 399 } 400 } else { 401 mesh_path_add(orig_addr, sdata); 402 mpath = mesh_path_lookup(orig_addr, sdata); 403 if (!mpath) { 404 rcu_read_unlock(); 405 return 0; 406 } 407 spin_lock_bh(&mpath->state_lock); 408 } 409 410 if (fresh_info) { 411 mesh_path_assign_nexthop(mpath, sta); 412 mpath->flags |= MESH_PATH_SN_VALID; 413 mpath->metric = new_metric; 414 mpath->sn = orig_sn; 415 mpath->exp_time = time_after(mpath->exp_time, exp_time) 416 ? mpath->exp_time : exp_time; 417 mesh_path_activate(mpath); 418 spin_unlock_bh(&mpath->state_lock); 419 mesh_path_tx_pending(mpath); 420 /* draft says preq_id should be saved to, but there does 421 * not seem to be any use for it, skipping by now 422 */ 423 } else 424 spin_unlock_bh(&mpath->state_lock); 425 } 426 427 /* Update and check transmitter routing info */ 428 ta = mgmt->sa; 429 if (memcmp(orig_addr, ta, ETH_ALEN) == 0) 430 fresh_info = false; 431 else { 432 fresh_info = true; 433 434 mpath = mesh_path_lookup(ta, sdata); 435 if (mpath) { 436 spin_lock_bh(&mpath->state_lock); 437 if ((mpath->flags & MESH_PATH_FIXED) || 438 ((mpath->flags & MESH_PATH_ACTIVE) && 439 (last_hop_metric > mpath->metric))) 440 fresh_info = false; 441 } else { 442 mesh_path_add(ta, sdata); 443 mpath = mesh_path_lookup(ta, sdata); 444 if (!mpath) { 445 rcu_read_unlock(); 446 return 0; 447 } 448 spin_lock_bh(&mpath->state_lock); 449 } 450 451 if (fresh_info) { 452 mesh_path_assign_nexthop(mpath, sta); 453 mpath->flags &= ~MESH_PATH_SN_VALID; 454 mpath->metric = last_hop_metric; 455 mpath->exp_time = time_after(mpath->exp_time, exp_time) 456 ? mpath->exp_time : exp_time; 457 mesh_path_activate(mpath); 458 spin_unlock_bh(&mpath->state_lock); 459 mesh_path_tx_pending(mpath); 460 } else 461 spin_unlock_bh(&mpath->state_lock); 462 } 463 464 rcu_read_unlock(); 465 466 return process ? new_metric : 0; 467} 468 469static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 470 struct ieee80211_mgmt *mgmt, 471 u8 *preq_elem, u32 metric) 472{ 473 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 474 struct mesh_path *mpath; 475 u8 *target_addr, *orig_addr; 476 u8 target_flags, ttl; 477 u32 orig_sn, target_sn, lifetime; 478 bool reply = false; 479 bool forward = true; 480 481 /* Update target SN, if present */ 482 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 483 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 484 target_sn = PREQ_IE_TARGET_SN(preq_elem); 485 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 486 target_flags = PREQ_IE_TARGET_F(preq_elem); 487 488 mhwmp_dbg("received PREQ from %pM\n", orig_addr); 489 490 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) { 491 mhwmp_dbg("PREQ is for us\n"); 492 forward = false; 493 reply = true; 494 metric = 0; 495 if (time_after(jiffies, ifmsh->last_sn_update + 496 net_traversal_jiffies(sdata)) || 497 time_before(jiffies, ifmsh->last_sn_update)) { 498 target_sn = ++ifmsh->sn; 499 ifmsh->last_sn_update = jiffies; 500 } 501 } else { 502 rcu_read_lock(); 503 mpath = mesh_path_lookup(target_addr, sdata); 504 if (mpath) { 505 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 506 SN_LT(mpath->sn, target_sn)) { 507 mpath->sn = target_sn; 508 mpath->flags |= MESH_PATH_SN_VALID; 509 } else if ((!(target_flags & MP_F_DO)) && 510 (mpath->flags & MESH_PATH_ACTIVE)) { 511 reply = true; 512 metric = mpath->metric; 513 target_sn = mpath->sn; 514 if (target_flags & MP_F_RF) 515 target_flags |= MP_F_DO; 516 else 517 forward = false; 518 } 519 } 520 rcu_read_unlock(); 521 } 522 523 if (reply) { 524 lifetime = PREQ_IE_LIFETIME(preq_elem); 525 ttl = ifmsh->mshcfg.dot11MeshTTL; 526 if (ttl != 0) { 527 mhwmp_dbg("replying to the PREQ\n"); 528 mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr, 529 cpu_to_le32(target_sn), 0, orig_addr, 530 cpu_to_le32(orig_sn), mgmt->sa, 0, ttl, 531 cpu_to_le32(lifetime), cpu_to_le32(metric), 532 0, sdata); 533 } else 534 ifmsh->mshstats.dropped_frames_ttl++; 535 } 536 537 if (forward) { 538 u32 preq_id; 539 u8 hopcount, flags; 540 541 ttl = PREQ_IE_TTL(preq_elem); 542 lifetime = PREQ_IE_LIFETIME(preq_elem); 543 if (ttl <= 1) { 544 ifmsh->mshstats.dropped_frames_ttl++; 545 return; 546 } 547 mhwmp_dbg("forwarding the PREQ from %pM\n", orig_addr); 548 --ttl; 549 flags = PREQ_IE_FLAGS(preq_elem); 550 preq_id = PREQ_IE_PREQ_ID(preq_elem); 551 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 552 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 553 cpu_to_le32(orig_sn), target_flags, target_addr, 554 cpu_to_le32(target_sn), broadcast_addr, 555 hopcount, ttl, cpu_to_le32(lifetime), 556 cpu_to_le32(metric), cpu_to_le32(preq_id), 557 sdata); 558 ifmsh->mshstats.fwded_mcast++; 559 ifmsh->mshstats.fwded_frames++; 560 } 561} 562 563 564static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 565 struct ieee80211_mgmt *mgmt, 566 u8 *prep_elem, u32 metric) 567{ 568 struct mesh_path *mpath; 569 u8 *target_addr, *orig_addr; 570 u8 ttl, hopcount, flags; 571 u8 next_hop[ETH_ALEN]; 572 u32 target_sn, orig_sn, lifetime; 573 574 mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem)); 575 576 /* Note that we divert from the draft nomenclature and denominate 577 * destination to what the draft refers to as origininator. So in this 578 * function destnation refers to the final destination of the PREP, 579 * which corresponds with the originator of the PREQ which this PREP 580 * replies 581 */ 582 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 583 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) 584 /* destination, no forwarding required */ 585 return; 586 587 ttl = PREP_IE_TTL(prep_elem); 588 if (ttl <= 1) { 589 sdata->u.mesh.mshstats.dropped_frames_ttl++; 590 return; 591 } 592 593 rcu_read_lock(); 594 mpath = mesh_path_lookup(target_addr, sdata); 595 if (mpath) 596 spin_lock_bh(&mpath->state_lock); 597 else 598 goto fail; 599 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 600 spin_unlock_bh(&mpath->state_lock); 601 goto fail; 602 } 603 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN); 604 spin_unlock_bh(&mpath->state_lock); 605 --ttl; 606 flags = PREP_IE_FLAGS(prep_elem); 607 lifetime = PREP_IE_LIFETIME(prep_elem); 608 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 609 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 610 target_sn = PREP_IE_TARGET_SN(prep_elem); 611 orig_sn = PREP_IE_ORIG_SN(prep_elem); 612 613 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 614 cpu_to_le32(orig_sn), 0, target_addr, 615 cpu_to_le32(target_sn), next_hop, hopcount, 616 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric), 617 0, sdata); 618 rcu_read_unlock(); 619 620 sdata->u.mesh.mshstats.fwded_unicast++; 621 sdata->u.mesh.mshstats.fwded_frames++; 622 return; 623 624fail: 625 rcu_read_unlock(); 626 sdata->u.mesh.mshstats.dropped_frames_no_route++; 627} 628 629static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 630 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 631{ 632 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 633 struct mesh_path *mpath; 634 u8 ttl; 635 u8 *ta, *target_addr; 636 u8 target_flags; 637 u32 target_sn; 638 u16 target_rcode; 639 640 ta = mgmt->sa; 641 ttl = PERR_IE_TTL(perr_elem); 642 if (ttl <= 1) { 643 ifmsh->mshstats.dropped_frames_ttl++; 644 return; 645 } 646 ttl--; 647 target_flags = PERR_IE_TARGET_FLAGS(perr_elem); 648 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 649 target_sn = PERR_IE_TARGET_SN(perr_elem); 650 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 651 652 rcu_read_lock(); 653 mpath = mesh_path_lookup(target_addr, sdata); 654 if (mpath) { 655 spin_lock_bh(&mpath->state_lock); 656 if (mpath->flags & MESH_PATH_ACTIVE && 657 memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 && 658 (!(mpath->flags & MESH_PATH_SN_VALID) || 659 SN_GT(target_sn, mpath->sn))) { 660 mpath->flags &= ~MESH_PATH_ACTIVE; 661 mpath->sn = target_sn; 662 spin_unlock_bh(&mpath->state_lock); 663 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn), 664 cpu_to_le16(target_rcode), 665 broadcast_addr, sdata); 666 } else 667 spin_unlock_bh(&mpath->state_lock); 668 } 669 rcu_read_unlock(); 670} 671 672static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 673 struct ieee80211_mgmt *mgmt, 674 struct ieee80211_rann_ie *rann) 675{ 676 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 677 struct mesh_path *mpath; 678 u8 *ta; 679 u8 ttl, flags, hopcount; 680 u8 *orig_addr; 681 u32 orig_sn, metric; 682 683 ta = mgmt->sa; 684 ttl = rann->rann_ttl; 685 if (ttl <= 1) { 686 ifmsh->mshstats.dropped_frames_ttl++; 687 return; 688 } 689 ttl--; 690 flags = rann->rann_flags; 691 orig_addr = rann->rann_addr; 692 orig_sn = rann->rann_seq; 693 hopcount = rann->rann_hopcount; 694 hopcount++; 695 metric = rann->rann_metric; 696 mhwmp_dbg("received RANN from %pM\n", orig_addr); 697 698 rcu_read_lock(); 699 mpath = mesh_path_lookup(orig_addr, sdata); 700 if (!mpath) { 701 mesh_path_add(orig_addr, sdata); 702 mpath = mesh_path_lookup(orig_addr, sdata); 703 if (!mpath) { 704 rcu_read_unlock(); 705 sdata->u.mesh.mshstats.dropped_frames_no_route++; 706 return; 707 } 708 mesh_queue_preq(mpath, 709 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 710 } 711 if (mpath->sn < orig_sn) { 712 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 713 cpu_to_le32(orig_sn), 714 0, NULL, 0, broadcast_addr, 715 hopcount, ttl, 0, 716 cpu_to_le32(metric + mpath->metric), 717 0, sdata); 718 mpath->sn = orig_sn; 719 } 720 rcu_read_unlock(); 721} 722 723 724void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 725 struct ieee80211_mgmt *mgmt, 726 size_t len) 727{ 728 struct ieee802_11_elems elems; 729 size_t baselen; 730 u32 last_hop_metric; 731 732 /* need action_code */ 733 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 734 return; 735 736 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 737 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 738 len - baselen, &elems); 739 740 if (elems.preq) { 741 if (elems.preq_len != 37) 742 /* Right now we support just 1 destination and no AE */ 743 return; 744 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 745 MPATH_PREQ); 746 if (last_hop_metric) 747 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 748 last_hop_metric); 749 } 750 if (elems.prep) { 751 if (elems.prep_len != 31) 752 /* Right now we support no AE */ 753 return; 754 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 755 MPATH_PREP); 756 if (last_hop_metric) 757 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 758 last_hop_metric); 759 } 760 if (elems.perr) { 761 if (elems.perr_len != 15) 762 /* Right now we support only one destination per PERR */ 763 return; 764 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 765 } 766 if (elems.rann) 767 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 768} 769 770/** 771 * mesh_queue_preq - queue a PREQ to a given destination 772 * 773 * @mpath: mesh path to discover 774 * @flags: special attributes of the PREQ to be sent 775 * 776 * Locking: the function must be called from within a rcu read lock block. 777 * 778 */ 779static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 780{ 781 struct ieee80211_sub_if_data *sdata = mpath->sdata; 782 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 783 struct mesh_preq_queue *preq_node; 784 785 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 786 if (!preq_node) { 787 mhwmp_dbg("could not allocate PREQ node\n"); 788 return; 789 } 790 791 spin_lock(&ifmsh->mesh_preq_queue_lock); 792 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 793 spin_unlock(&ifmsh->mesh_preq_queue_lock); 794 kfree(preq_node); 795 if (printk_ratelimit()) 796 mhwmp_dbg("PREQ node queue full\n"); 797 return; 798 } 799 800 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 801 preq_node->flags = flags; 802 803 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 804 ++ifmsh->preq_queue_len; 805 spin_unlock(&ifmsh->mesh_preq_queue_lock); 806 807 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 808 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 809 810 else if (time_before(jiffies, ifmsh->last_preq)) { 811 /* avoid long wait if did not send preqs for a long time 812 * and jiffies wrapped around 813 */ 814 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 815 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 816 } else 817 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 818 min_preq_int_jiff(sdata)); 819} 820 821/** 822 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 823 * 824 * @sdata: local mesh subif 825 */ 826void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 827{ 828 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 829 struct mesh_preq_queue *preq_node; 830 struct mesh_path *mpath; 831 u8 ttl, target_flags; 832 u32 lifetime; 833 834 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 835 if (!ifmsh->preq_queue_len || 836 time_before(jiffies, ifmsh->last_preq + 837 min_preq_int_jiff(sdata))) { 838 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 839 return; 840 } 841 842 preq_node = list_first_entry(&ifmsh->preq_queue.list, 843 struct mesh_preq_queue, list); 844 list_del(&preq_node->list); 845 --ifmsh->preq_queue_len; 846 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 847 848 rcu_read_lock(); 849 mpath = mesh_path_lookup(preq_node->dst, sdata); 850 if (!mpath) 851 goto enddiscovery; 852 853 spin_lock_bh(&mpath->state_lock); 854 if (preq_node->flags & PREQ_Q_F_START) { 855 if (mpath->flags & MESH_PATH_RESOLVING) { 856 spin_unlock_bh(&mpath->state_lock); 857 goto enddiscovery; 858 } else { 859 mpath->flags &= ~MESH_PATH_RESOLVED; 860 mpath->flags |= MESH_PATH_RESOLVING; 861 mpath->discovery_retries = 0; 862 mpath->discovery_timeout = disc_timeout_jiff(sdata); 863 } 864 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 865 mpath->flags & MESH_PATH_RESOLVED) { 866 mpath->flags &= ~MESH_PATH_RESOLVING; 867 spin_unlock_bh(&mpath->state_lock); 868 goto enddiscovery; 869 } 870 871 ifmsh->last_preq = jiffies; 872 873 if (time_after(jiffies, ifmsh->last_sn_update + 874 net_traversal_jiffies(sdata)) || 875 time_before(jiffies, ifmsh->last_sn_update)) { 876 ++ifmsh->sn; 877 sdata->u.mesh.last_sn_update = jiffies; 878 } 879 lifetime = default_lifetime(sdata); 880 ttl = sdata->u.mesh.mshcfg.dot11MeshTTL; 881 if (ttl == 0) { 882 sdata->u.mesh.mshstats.dropped_frames_ttl++; 883 spin_unlock_bh(&mpath->state_lock); 884 goto enddiscovery; 885 } 886 887 if (preq_node->flags & PREQ_Q_F_REFRESH) 888 target_flags = MP_F_DO; 889 else 890 target_flags = MP_F_RF; 891 892 spin_unlock_bh(&mpath->state_lock); 893 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, 894 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst, 895 cpu_to_le32(mpath->sn), broadcast_addr, 0, 896 ttl, cpu_to_le32(lifetime), 0, 897 cpu_to_le32(ifmsh->preq_id++), sdata); 898 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 899 900enddiscovery: 901 rcu_read_unlock(); 902 kfree(preq_node); 903} 904 905/** 906 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame 907 * 908 * @skb: 802.11 frame to be sent 909 * @sdata: network subif the frame will be sent through 910 * 911 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is 912 * found, the function will start a path discovery and queue the frame so it is 913 * sent when the path is resolved. This means the caller must not free the skb 914 * in this case. 915 */ 916int mesh_nexthop_lookup(struct sk_buff *skb, 917 struct ieee80211_sub_if_data *sdata) 918{ 919 struct sk_buff *skb_to_free = NULL; 920 struct mesh_path *mpath; 921 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 922 u8 *target_addr = hdr->addr3; 923 int err = 0; 924 925 rcu_read_lock(); 926 mpath = mesh_path_lookup(target_addr, sdata); 927 928 if (!mpath) { 929 mesh_path_add(target_addr, sdata); 930 mpath = mesh_path_lookup(target_addr, sdata); 931 if (!mpath) { 932 sdata->u.mesh.mshstats.dropped_frames_no_route++; 933 err = -ENOSPC; 934 goto endlookup; 935 } 936 } 937 938 if (mpath->flags & MESH_PATH_ACTIVE) { 939 if (time_after(jiffies, 940 mpath->exp_time - 941 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 942 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) && 943 !(mpath->flags & MESH_PATH_RESOLVING) && 944 !(mpath->flags & MESH_PATH_FIXED)) { 945 mesh_queue_preq(mpath, 946 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 947 } 948 memcpy(hdr->addr1, mpath->next_hop->sta.addr, ETH_ALEN); 949 } else { 950 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 951 if (!(mpath->flags & MESH_PATH_RESOLVING)) { 952 /* Start discovery only if it is not running yet */ 953 mesh_queue_preq(mpath, PREQ_Q_F_START); 954 } 955 956 if (skb_queue_len(&mpath->frame_queue) >= 957 MESH_FRAME_QUEUE_LEN) 958 skb_to_free = skb_dequeue(&mpath->frame_queue); 959 960 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 961 skb_queue_tail(&mpath->frame_queue, skb); 962 if (skb_to_free) 963 mesh_path_discard_frame(skb_to_free, sdata); 964 err = -ENOENT; 965 } 966 967endlookup: 968 rcu_read_unlock(); 969 return err; 970} 971 972void mesh_path_timer(unsigned long data) 973{ 974 struct ieee80211_sub_if_data *sdata; 975 struct mesh_path *mpath; 976 977 rcu_read_lock(); 978 mpath = (struct mesh_path *) data; 979 mpath = rcu_dereference(mpath); 980 if (!mpath) 981 goto endmpathtimer; 982 sdata = mpath->sdata; 983 984 if (sdata->local->quiescing) { 985 rcu_read_unlock(); 986 return; 987 } 988 989 spin_lock_bh(&mpath->state_lock); 990 if (mpath->flags & MESH_PATH_RESOLVED || 991 (!(mpath->flags & MESH_PATH_RESOLVING))) 992 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 993 else if (mpath->discovery_retries < max_preq_retries(sdata)) { 994 ++mpath->discovery_retries; 995 mpath->discovery_timeout *= 2; 996 mesh_queue_preq(mpath, 0); 997 } else { 998 mpath->flags = 0; 999 mpath->exp_time = jiffies; 1000 mesh_path_flush_pending(mpath); 1001 } 1002 1003 spin_unlock_bh(&mpath->state_lock); 1004endmpathtimer: 1005 rcu_read_unlock(); 1006} 1007 1008void 1009mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1010{ 1011 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1012 1013 mesh_path_sel_frame_tx(MPATH_RANN, 0, sdata->vif.addr, 1014 cpu_to_le32(++ifmsh->sn), 1015 0, NULL, 0, broadcast_addr, 1016 0, MESH_TTL, 0, 0, 0, sdata); 1017} 1018