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 "mesh.h" 11 12 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG 13 #define mhwmp_dbg(fmt, args...) printk(KERN_DEBUG "Mesh HWMP: " fmt, ##args) 14 #else 15 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0) 16 #endif 17 18 #define TEST_FRAME_LEN 8192 19 #define MAX_METRIC 0xffffffff 20 #define ARITH_SHIFT 8 21 22 /* Number of frames buffered per destination for unresolved destinations */ 23 #define MESH_FRAME_QUEUE_LEN 10 24 #define MAX_PREQ_QUEUE_LEN 64 25 26 /* Destination only */ 27 #define MP_F_DO 0x1 28 /* Reply and forward */ 29 #define MP_F_RF 0x2 30 /* Unknown Sequence Number */ 31 #define MP_F_USN 0x01 32 /* Reason code Present */ 33 #define MP_F_RCODE 0x02 34 35 static void mesh_queue_preq(struct mesh_path *, u8); 36 37 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae) 38 { 39 if (ae) 40 offset += 6; 41 return get_unaligned_le32(preq_elem + offset); 42 } 43 44 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae) 45 { 46 if (ae) 47 offset += 6; 48 return get_unaligned_le16(preq_elem + offset); 49 } 50 51 /* HWMP IE processing macros */ 52 #define AE_F (1<<6) 53 #define AE_F_SET(x) (*x & AE_F) 54 #define PREQ_IE_FLAGS(x) (*(x)) 55 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 56 #define PREQ_IE_TTL(x) (*(x + 2)) 57 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 58 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 59 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0); 60 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)); 61 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)); 62 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 63 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 64 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)); 65 66 67 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 68 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 69 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 70 #define PREP_IE_ORIG_ADDR(x) (x + 3) 71 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 9, 0); 72 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)); 73 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)); 74 #define PREP_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 75 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 27, AE_F_SET(x)); 76 77 #define PERR_IE_TTL(x) (*(x)) 78 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) 79 #define PERR_IE_TARGET_ADDR(x) (x + 3) 80 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0); 81 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0); 82 83 #define MSEC_TO_TU(x) (x*1000/1024) 84 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0) 85 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0) 86 87 #define net_traversal_jiffies(s) \ 88 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 89 #define default_lifetime(s) \ 90 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 91 #define min_preq_int_jiff(s) \ 92 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 93 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 94 #define disc_timeout_jiff(s) \ 95 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 96 97 enum mpath_frame_type { 98 MPATH_PREQ = 0, 99 MPATH_PREP, 100 MPATH_PERR, 101 MPATH_RANN 102 }; 103 104 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 105 106 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 107 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target, 108 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl, 109 __le32 lifetime, __le32 metric, __le32 preq_id, 110 struct ieee80211_sub_if_data *sdata) 111 { 112 struct ieee80211_local *local = sdata->local; 113 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 114 struct ieee80211_mgmt *mgmt; 115 u8 *pos; 116 int ie_len; 117 118 if (!skb) 119 return -1; 120 skb_reserve(skb, local->hw.extra_tx_headroom); 121 /* 25 is the size of the common mgmt part (24) plus the size of the 122 * common action part (1) 123 */ 124 mgmt = (struct ieee80211_mgmt *) 125 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 126 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 127 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 128 IEEE80211_STYPE_ACTION); 129 130 memcpy(mgmt->da, da, ETH_ALEN); 131 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 132 /* BSSID == SA */ 133 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN); 134 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; 135 mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION; 136 137 switch (action) { 138 case MPATH_PREQ: 139 mhwmp_dbg("sending PREQ to %pM\n", target); 140 ie_len = 37; 141 pos = skb_put(skb, 2 + ie_len); 142 *pos++ = WLAN_EID_PREQ; 143 break; 144 case MPATH_PREP: 145 mhwmp_dbg("sending PREP to %pM\n", target); 146 ie_len = 31; 147 pos = skb_put(skb, 2 + ie_len); 148 *pos++ = WLAN_EID_PREP; 149 break; 150 case MPATH_RANN: 151 mhwmp_dbg("sending RANN from %pM\n", orig_addr); 152 ie_len = sizeof(struct ieee80211_rann_ie); 153 pos = skb_put(skb, 2 + ie_len); 154 *pos++ = WLAN_EID_RANN; 155 break; 156 default: 157 kfree_skb(skb); 158 return -ENOTSUPP; 159 break; 160 } 161 *pos++ = ie_len; 162 *pos++ = flags; 163 *pos++ = hop_count; 164 *pos++ = ttl; 165 if (action == MPATH_PREQ) { 166 memcpy(pos, &preq_id, 4); 167 pos += 4; 168 } 169 memcpy(pos, orig_addr, ETH_ALEN); 170 pos += ETH_ALEN; 171 memcpy(pos, &orig_sn, 4); 172 pos += 4; 173 if (action != MPATH_RANN) { 174 memcpy(pos, &lifetime, 4); 175 pos += 4; 176 } 177 memcpy(pos, &metric, 4); 178 pos += 4; 179 if (action == MPATH_PREQ) { 180 /* destination count */ 181 *pos++ = 1; 182 *pos++ = target_flags; 183 } 184 if (action != MPATH_RANN) { 185 memcpy(pos, target, ETH_ALEN); 186 pos += ETH_ALEN; 187 memcpy(pos, &target_sn, 4); 188 } 189 190 ieee80211_tx_skb(sdata, skb); 191 return 0; 192 } 193 194 /** 195 * mesh_send_path error - Sends a PERR mesh management frame 196 * 197 * @target: broken destination 198 * @target_sn: SN of the broken destination 199 * @target_rcode: reason code for this PERR 200 * @ra: node this frame is addressed to 201 */ 202 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, 203 __le16 target_rcode, const u8 *ra, 204 struct ieee80211_sub_if_data *sdata) 205 { 206 struct ieee80211_local *local = sdata->local; 207 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 208 struct ieee80211_mgmt *mgmt; 209 u8 *pos; 210 int ie_len; 211 212 if (!skb) 213 return -1; 214 skb_reserve(skb, local->hw.extra_tx_headroom); 215 /* 25 is the size of the common mgmt part (24) plus the size of the 216 * common action part (1) 217 */ 218 mgmt = (struct ieee80211_mgmt *) 219 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 220 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 221 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 222 IEEE80211_STYPE_ACTION); 223 224 memcpy(mgmt->da, ra, ETH_ALEN); 225 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 226 /* BSSID is left zeroed, wildcard value */ 227 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; 228 mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION; 229 ie_len = 15; 230 pos = skb_put(skb, 2 + ie_len); 231 *pos++ = WLAN_EID_PERR; 232 *pos++ = ie_len; 233 /* ttl */ 234 *pos++ = MESH_TTL; 235 /* number of destinations */ 236 *pos++ = 1; 237 /* 238 * flags bit, bit 1 is unset if we know the sequence number and 239 * bit 2 is set if we have a reason code 240 */ 241 *pos = 0; 242 if (!target_sn) 243 *pos |= MP_F_USN; 244 if (target_rcode) 245 *pos |= MP_F_RCODE; 246 pos++; 247 memcpy(pos, target, ETH_ALEN); 248 pos += ETH_ALEN; 249 memcpy(pos, &target_sn, 4); 250 pos += 4; 251 memcpy(pos, &target_rcode, 2); 252 253 ieee80211_tx_skb(sdata, skb); 254 return 0; 255 } 256 257 void ieee80211s_update_metric(struct ieee80211_local *local, 258 struct sta_info *stainfo, struct sk_buff *skb) 259 { 260 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); 261 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 262 int failed; 263 264 if (!ieee80211_is_data(hdr->frame_control)) 265 return; 266 267 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 268 269 /* moving average, scaled to 100 */ 270 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed); 271 if (stainfo->fail_avg > 95) 272 mesh_plink_broken(stainfo); 273 } 274 275 static u32 airtime_link_metric_get(struct ieee80211_local *local, 276 struct sta_info *sta) 277 { 278 struct ieee80211_supported_band *sband; 279 /* This should be adjusted for each device */ 280 int device_constant = 1 << ARITH_SHIFT; 281 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 282 int s_unit = 1 << ARITH_SHIFT; 283 int rate, err; 284 u32 tx_time, estimated_retx; 285 u64 result; 286 287 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 288 289 if (sta->fail_avg >= 100) 290 return MAX_METRIC; 291 292 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS) 293 return MAX_METRIC; 294 295 err = (sta->fail_avg << ARITH_SHIFT) / 100; 296 297 /* bitrate is in units of 100 Kbps, while we need rate in units of 298 * 1Mbps. This will be corrected on tx_time computation. 299 */ 300 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate; 301 tx_time = (device_constant + 10 * test_frame_len / rate); 302 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 303 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 304 return (u32)result; 305 } 306 307 /** 308 * hwmp_route_info_get - Update routing info to originator and transmitter 309 * 310 * @sdata: local mesh subif 311 * @mgmt: mesh management frame 312 * @hwmp_ie: hwmp information element (PREP or PREQ) 313 * 314 * This function updates the path routing information to the originator and the 315 * transmitter of a HWMP PREQ or PREP frame. 316 * 317 * Returns: metric to frame originator or 0 if the frame should not be further 318 * processed 319 * 320 * Notes: this function is the only place (besides user-provided info) where 321 * path routing information is updated. 322 */ 323 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 324 struct ieee80211_mgmt *mgmt, 325 u8 *hwmp_ie, enum mpath_frame_type action) 326 { 327 struct ieee80211_local *local = sdata->local; 328 struct mesh_path *mpath; 329 struct sta_info *sta; 330 bool fresh_info; 331 u8 *orig_addr, *ta; 332 u32 orig_sn, orig_metric; 333 unsigned long orig_lifetime, exp_time; 334 u32 last_hop_metric, new_metric; 335 bool process = true; 336 337 rcu_read_lock(); 338 sta = sta_info_get(local, mgmt->sa); 339 if (!sta) { 340 rcu_read_unlock(); 341 return 0; 342 } 343 344 last_hop_metric = airtime_link_metric_get(local, sta); 345 /* Update and check originator routing info */ 346 fresh_info = true; 347 348 switch (action) { 349 case MPATH_PREQ: 350 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 351 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie); 352 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 353 orig_metric = PREQ_IE_METRIC(hwmp_ie); 354 break; 355 case MPATH_PREP: 356 /* Originator here refers to the MP that was the destination in 357 * the Path Request. The draft refers to that MP as the 358 * destination address, even though usually it is the origin of 359 * the PREP frame. We divert from the nomenclature in the draft 360 * so that we can easily use a single function to gather path 361 * information from both PREQ and PREP frames. 362 */ 363 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie); 364 orig_sn = PREP_IE_ORIG_SN(hwmp_ie); 365 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 366 orig_metric = PREP_IE_METRIC(hwmp_ie); 367 break; 368 default: 369 rcu_read_unlock(); 370 return 0; 371 } 372 new_metric = orig_metric + last_hop_metric; 373 if (new_metric < orig_metric) 374 new_metric = MAX_METRIC; 375 exp_time = TU_TO_EXP_TIME(orig_lifetime); 376 377 if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 378 /* This MP is the originator, we are not interested in this 379 * frame, except for updating transmitter's path info. 380 */ 381 process = false; 382 fresh_info = false; 383 } else { 384 mpath = mesh_path_lookup(orig_addr, sdata); 385 if (mpath) { 386 spin_lock_bh(&mpath->state_lock); 387 if (mpath->flags & MESH_PATH_FIXED) 388 fresh_info = false; 389 else if ((mpath->flags & MESH_PATH_ACTIVE) && 390 (mpath->flags & MESH_PATH_SN_VALID)) { 391 if (SN_GT(mpath->sn, orig_sn) || 392 (mpath->sn == orig_sn && 393 action == MPATH_PREQ && 394 new_metric > mpath->metric)) { 395 process = false; 396 fresh_info = false; 397 } 398 } 399 } else { 400 mesh_path_add(orig_addr, sdata); 401 mpath = mesh_path_lookup(orig_addr, sdata); 402 if (!mpath) { 403 rcu_read_unlock(); 404 return 0; 405 } 406 spin_lock_bh(&mpath->state_lock); 407 } 408 409 if (fresh_info) { 410 mesh_path_assign_nexthop(mpath, sta); 411 mpath->flags |= MESH_PATH_SN_VALID; 412 mpath->metric = new_metric; 413 mpath->sn = orig_sn; 414 mpath->exp_time = time_after(mpath->exp_time, exp_time) 415 ? mpath->exp_time : exp_time; 416 mesh_path_activate(mpath); 417 spin_unlock_bh(&mpath->state_lock); 418 mesh_path_tx_pending(mpath); 419 /* draft says preq_id should be saved to, but there does 420 * not seem to be any use for it, skipping by now 421 */ 422 } else 423 spin_unlock_bh(&mpath->state_lock); 424 } 425 426 /* Update and check transmitter routing info */ 427 ta = mgmt->sa; 428 if (memcmp(orig_addr, ta, ETH_ALEN) == 0) 429 fresh_info = false; 430 else { 431 fresh_info = true; 432 433 mpath = mesh_path_lookup(ta, sdata); 434 if (mpath) { 435 spin_lock_bh(&mpath->state_lock); 436 if ((mpath->flags & MESH_PATH_FIXED) || 437 ((mpath->flags & MESH_PATH_ACTIVE) && 438 (last_hop_metric > mpath->metric))) 439 fresh_info = false; 440 } else { 441 mesh_path_add(ta, sdata); 442 mpath = mesh_path_lookup(ta, sdata); 443 if (!mpath) { 444 rcu_read_unlock(); 445 return 0; 446 } 447 spin_lock_bh(&mpath->state_lock); 448 } 449 450 if (fresh_info) { 451 mesh_path_assign_nexthop(mpath, sta); 452 mpath->flags &= ~MESH_PATH_SN_VALID; 453 mpath->metric = last_hop_metric; 454 mpath->exp_time = time_after(mpath->exp_time, exp_time) 455 ? mpath->exp_time : exp_time; 456 mesh_path_activate(mpath); 457 spin_unlock_bh(&mpath->state_lock); 458 mesh_path_tx_pending(mpath); 459 } else 460 spin_unlock_bh(&mpath->state_lock); 461 } 462 463 rcu_read_unlock(); 464 465 return process ? new_metric : 0; 466 } 467 468 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 469 struct ieee80211_mgmt *mgmt, 470 u8 *preq_elem, u32 metric) 471 { 472 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 473 struct mesh_path *mpath; 474 u8 *target_addr, *orig_addr; 475 u8 target_flags, ttl; 476 u32 orig_sn, target_sn, lifetime; 477 bool reply = false; 478 bool forward = true; 479 480 /* Update target SN, if present */ 481 target_addr = PREQ_IE_TARGET_ADDR(preq_elem); 482 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 483 target_sn = PREQ_IE_TARGET_SN(preq_elem); 484 orig_sn = PREQ_IE_ORIG_SN(preq_elem); 485 target_flags = PREQ_IE_TARGET_F(preq_elem); 486 487 mhwmp_dbg("received PREQ from %pM\n", orig_addr); 488 489 if (memcmp(target_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 490 mhwmp_dbg("PREQ is for us\n"); 491 forward = false; 492 reply = true; 493 metric = 0; 494 if (time_after(jiffies, ifmsh->last_sn_update + 495 net_traversal_jiffies(sdata)) || 496 time_before(jiffies, ifmsh->last_sn_update)) { 497 target_sn = ++ifmsh->sn; 498 ifmsh->last_sn_update = jiffies; 499 } 500 } else { 501 rcu_read_lock(); 502 mpath = mesh_path_lookup(target_addr, sdata); 503 if (mpath) { 504 if ((!(mpath->flags & MESH_PATH_SN_VALID)) || 505 SN_LT(mpath->sn, target_sn)) { 506 mpath->sn = target_sn; 507 mpath->flags |= MESH_PATH_SN_VALID; 508 } else if ((!(target_flags & MP_F_DO)) && 509 (mpath->flags & MESH_PATH_ACTIVE)) { 510 reply = true; 511 metric = mpath->metric; 512 target_sn = mpath->sn; 513 if (target_flags & MP_F_RF) 514 target_flags |= MP_F_DO; 515 else 516 forward = false; 517 } 518 } 519 rcu_read_unlock(); 520 } 521 522 if (reply) { 523 lifetime = PREQ_IE_LIFETIME(preq_elem); 524 ttl = ifmsh->mshcfg.dot11MeshTTL; 525 if (ttl != 0) { 526 mhwmp_dbg("replying to the PREQ\n"); 527 mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr, 528 cpu_to_le32(target_sn), 0, orig_addr, 529 cpu_to_le32(orig_sn), mgmt->sa, 0, ttl, 530 cpu_to_le32(lifetime), cpu_to_le32(metric), 531 0, sdata); 532 } else 533 ifmsh->mshstats.dropped_frames_ttl++; 534 } 535 536 if (forward) { 537 u32 preq_id; 538 u8 hopcount, flags; 539 540 ttl = PREQ_IE_TTL(preq_elem); 541 lifetime = PREQ_IE_LIFETIME(preq_elem); 542 if (ttl <= 1) { 543 ifmsh->mshstats.dropped_frames_ttl++; 544 return; 545 } 546 mhwmp_dbg("forwarding the PREQ from %pM\n", orig_addr); 547 --ttl; 548 flags = PREQ_IE_FLAGS(preq_elem); 549 preq_id = PREQ_IE_PREQ_ID(preq_elem); 550 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 551 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 552 cpu_to_le32(orig_sn), target_flags, target_addr, 553 cpu_to_le32(target_sn), broadcast_addr, 554 hopcount, ttl, cpu_to_le32(lifetime), 555 cpu_to_le32(metric), cpu_to_le32(preq_id), 556 sdata); 557 ifmsh->mshstats.fwded_mcast++; 558 ifmsh->mshstats.fwded_frames++; 559 } 560 } 561 562 563 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 564 struct ieee80211_mgmt *mgmt, 565 u8 *prep_elem, u32 metric) 566 { 567 struct mesh_path *mpath; 568 u8 *target_addr, *orig_addr; 569 u8 ttl, hopcount, flags; 570 u8 next_hop[ETH_ALEN]; 571 u32 target_sn, orig_sn, lifetime; 572 573 mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem)); 574 575 /* Note that we divert from the draft nomenclature and denominate 576 * destination to what the draft refers to as origininator. So in this 577 * function destnation refers to the final destination of the PREP, 578 * which corresponds with the originator of the PREQ which this PREP 579 * replies 580 */ 581 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 582 if (memcmp(target_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) 583 /* destination, no forwarding required */ 584 return; 585 586 ttl = PREP_IE_TTL(prep_elem); 587 if (ttl <= 1) { 588 sdata->u.mesh.mshstats.dropped_frames_ttl++; 589 return; 590 } 591 592 rcu_read_lock(); 593 mpath = mesh_path_lookup(target_addr, sdata); 594 if (mpath) 595 spin_lock_bh(&mpath->state_lock); 596 else 597 goto fail; 598 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 599 spin_unlock_bh(&mpath->state_lock); 600 goto fail; 601 } 602 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN); 603 spin_unlock_bh(&mpath->state_lock); 604 --ttl; 605 flags = PREP_IE_FLAGS(prep_elem); 606 lifetime = PREP_IE_LIFETIME(prep_elem); 607 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 608 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 609 target_sn = PREP_IE_TARGET_SN(prep_elem); 610 orig_sn = PREP_IE_ORIG_SN(prep_elem); 611 612 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 613 cpu_to_le32(orig_sn), 0, target_addr, 614 cpu_to_le32(target_sn), mpath->next_hop->sta.addr, hopcount, 615 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric), 616 0, sdata); 617 rcu_read_unlock(); 618 619 sdata->u.mesh.mshstats.fwded_unicast++; 620 sdata->u.mesh.mshstats.fwded_frames++; 621 return; 622 623 fail: 624 rcu_read_unlock(); 625 sdata->u.mesh.mshstats.dropped_frames_no_route++; 626 return; 627 } 628 629 static 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 } 671 672 static 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 } 722 723 724 void 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 */ 779 static 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, &ifmsh->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, &ifmsh->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 */ 826 void 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->dev->dev_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); 899 900 enddiscovery: 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 */ 916 int 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->dev->dev_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 } 966 967 endlookup: 968 rcu_read_unlock(); 969 return err; 970 } 971 972 void 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); 1004 endmpathtimer: 1005 rcu_read_unlock(); 1006 } 1007 1008 void 1009 mesh_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->dev->dev_addr, 1014 cpu_to_le32(++ifmsh->sn), 1015 0, NULL, 0, broadcast_addr, 1016 0, MESH_TTL, 0, 0, 0, sdata); 1017 } 1018