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 36 static void mesh_queue_preq(struct mesh_path *, u8); 37 38 static 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 45 static 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 98 enum mpath_frame_type { 99 MPATH_PREQ = 0, 100 MPATH_PREP, 101 MPATH_PERR, 102 MPATH_RANN 103 }; 104 105 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; 106 107 static 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 */ 203 int 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++ = 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 } 257 258 void 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 } 275 276 static 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 */ 324 static 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 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->vif.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.element_ttl; 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 inline struct sta_info * 564 next_hop_deref_protected(struct mesh_path *mpath) 565 { 566 return rcu_dereference_protected(mpath->next_hop, 567 lockdep_is_held(&mpath->state_lock)); 568 } 569 570 571 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 572 struct ieee80211_mgmt *mgmt, 573 u8 *prep_elem, u32 metric) 574 { 575 struct mesh_path *mpath; 576 u8 *target_addr, *orig_addr; 577 u8 ttl, hopcount, flags; 578 u8 next_hop[ETH_ALEN]; 579 u32 target_sn, orig_sn, lifetime; 580 581 mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem)); 582 583 /* Note that we divert from the draft nomenclature and denominate 584 * destination to what the draft refers to as origininator. So in this 585 * function destnation refers to the final destination of the PREP, 586 * which corresponds with the originator of the PREQ which this PREP 587 * replies 588 */ 589 target_addr = PREP_IE_TARGET_ADDR(prep_elem); 590 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) 591 /* destination, no forwarding required */ 592 return; 593 594 ttl = PREP_IE_TTL(prep_elem); 595 if (ttl <= 1) { 596 sdata->u.mesh.mshstats.dropped_frames_ttl++; 597 return; 598 } 599 600 rcu_read_lock(); 601 mpath = mesh_path_lookup(target_addr, sdata); 602 if (mpath) 603 spin_lock_bh(&mpath->state_lock); 604 else 605 goto fail; 606 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 607 spin_unlock_bh(&mpath->state_lock); 608 goto fail; 609 } 610 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN); 611 spin_unlock_bh(&mpath->state_lock); 612 --ttl; 613 flags = PREP_IE_FLAGS(prep_elem); 614 lifetime = PREP_IE_LIFETIME(prep_elem); 615 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 616 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 617 target_sn = PREP_IE_TARGET_SN(prep_elem); 618 orig_sn = PREP_IE_ORIG_SN(prep_elem); 619 620 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 621 cpu_to_le32(orig_sn), 0, target_addr, 622 cpu_to_le32(target_sn), next_hop, hopcount, 623 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric), 624 0, sdata); 625 rcu_read_unlock(); 626 627 sdata->u.mesh.mshstats.fwded_unicast++; 628 sdata->u.mesh.mshstats.fwded_frames++; 629 return; 630 631 fail: 632 rcu_read_unlock(); 633 sdata->u.mesh.mshstats.dropped_frames_no_route++; 634 } 635 636 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 637 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 638 { 639 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 640 struct mesh_path *mpath; 641 u8 ttl; 642 u8 *ta, *target_addr; 643 u32 target_sn; 644 u16 target_rcode; 645 646 ta = mgmt->sa; 647 ttl = PERR_IE_TTL(perr_elem); 648 if (ttl <= 1) { 649 ifmsh->mshstats.dropped_frames_ttl++; 650 return; 651 } 652 ttl--; 653 target_addr = PERR_IE_TARGET_ADDR(perr_elem); 654 target_sn = PERR_IE_TARGET_SN(perr_elem); 655 target_rcode = PERR_IE_TARGET_RCODE(perr_elem); 656 657 rcu_read_lock(); 658 mpath = mesh_path_lookup(target_addr, sdata); 659 if (mpath) { 660 spin_lock_bh(&mpath->state_lock); 661 if (mpath->flags & MESH_PATH_ACTIVE && 662 memcmp(ta, next_hop_deref_protected(mpath)->sta.addr, 663 ETH_ALEN) == 0 && 664 (!(mpath->flags & MESH_PATH_SN_VALID) || 665 SN_GT(target_sn, mpath->sn))) { 666 mpath->flags &= ~MESH_PATH_ACTIVE; 667 mpath->sn = target_sn; 668 spin_unlock_bh(&mpath->state_lock); 669 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn), 670 cpu_to_le16(target_rcode), 671 broadcast_addr, sdata); 672 } else 673 spin_unlock_bh(&mpath->state_lock); 674 } 675 rcu_read_unlock(); 676 } 677 678 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, 679 struct ieee80211_mgmt *mgmt, 680 struct ieee80211_rann_ie *rann) 681 { 682 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 683 struct mesh_path *mpath; 684 u8 ttl, flags, hopcount; 685 u8 *orig_addr; 686 u32 orig_sn, metric; 687 688 ttl = rann->rann_ttl; 689 if (ttl <= 1) { 690 ifmsh->mshstats.dropped_frames_ttl++; 691 return; 692 } 693 ttl--; 694 flags = rann->rann_flags; 695 orig_addr = rann->rann_addr; 696 orig_sn = rann->rann_seq; 697 hopcount = rann->rann_hopcount; 698 hopcount++; 699 metric = rann->rann_metric; 700 mhwmp_dbg("received RANN from %pM\n", orig_addr); 701 702 rcu_read_lock(); 703 mpath = mesh_path_lookup(orig_addr, sdata); 704 if (!mpath) { 705 mesh_path_add(orig_addr, sdata); 706 mpath = mesh_path_lookup(orig_addr, sdata); 707 if (!mpath) { 708 rcu_read_unlock(); 709 sdata->u.mesh.mshstats.dropped_frames_no_route++; 710 return; 711 } 712 mesh_queue_preq(mpath, 713 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 714 } 715 if (mpath->sn < orig_sn) { 716 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, 717 cpu_to_le32(orig_sn), 718 0, NULL, 0, broadcast_addr, 719 hopcount, ttl, 0, 720 cpu_to_le32(metric + mpath->metric), 721 0, sdata); 722 mpath->sn = orig_sn; 723 } 724 rcu_read_unlock(); 725 } 726 727 728 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 729 struct ieee80211_mgmt *mgmt, 730 size_t len) 731 { 732 struct ieee802_11_elems elems; 733 size_t baselen; 734 u32 last_hop_metric; 735 736 /* need action_code */ 737 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 738 return; 739 740 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 741 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 742 len - baselen, &elems); 743 744 if (elems.preq) { 745 if (elems.preq_len != 37) 746 /* Right now we support just 1 destination and no AE */ 747 return; 748 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, 749 MPATH_PREQ); 750 if (last_hop_metric) 751 hwmp_preq_frame_process(sdata, mgmt, elems.preq, 752 last_hop_metric); 753 } 754 if (elems.prep) { 755 if (elems.prep_len != 31) 756 /* Right now we support no AE */ 757 return; 758 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, 759 MPATH_PREP); 760 if (last_hop_metric) 761 hwmp_prep_frame_process(sdata, mgmt, elems.prep, 762 last_hop_metric); 763 } 764 if (elems.perr) { 765 if (elems.perr_len != 15) 766 /* Right now we support only one destination per PERR */ 767 return; 768 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 769 } 770 if (elems.rann) 771 hwmp_rann_frame_process(sdata, mgmt, elems.rann); 772 } 773 774 /** 775 * mesh_queue_preq - queue a PREQ to a given destination 776 * 777 * @mpath: mesh path to discover 778 * @flags: special attributes of the PREQ to be sent 779 * 780 * Locking: the function must be called from within a rcu read lock block. 781 * 782 */ 783 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 784 { 785 struct ieee80211_sub_if_data *sdata = mpath->sdata; 786 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 787 struct mesh_preq_queue *preq_node; 788 789 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 790 if (!preq_node) { 791 mhwmp_dbg("could not allocate PREQ node\n"); 792 return; 793 } 794 795 spin_lock(&ifmsh->mesh_preq_queue_lock); 796 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 797 spin_unlock(&ifmsh->mesh_preq_queue_lock); 798 kfree(preq_node); 799 if (printk_ratelimit()) 800 mhwmp_dbg("PREQ node queue full\n"); 801 return; 802 } 803 804 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 805 preq_node->flags = flags; 806 807 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 808 ++ifmsh->preq_queue_len; 809 spin_unlock(&ifmsh->mesh_preq_queue_lock); 810 811 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 812 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 813 814 else if (time_before(jiffies, ifmsh->last_preq)) { 815 /* avoid long wait if did not send preqs for a long time 816 * and jiffies wrapped around 817 */ 818 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 819 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 820 } else 821 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 822 min_preq_int_jiff(sdata)); 823 } 824 825 /** 826 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 827 * 828 * @sdata: local mesh subif 829 */ 830 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 831 { 832 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 833 struct mesh_preq_queue *preq_node; 834 struct mesh_path *mpath; 835 u8 ttl, target_flags; 836 u32 lifetime; 837 838 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 839 if (!ifmsh->preq_queue_len || 840 time_before(jiffies, ifmsh->last_preq + 841 min_preq_int_jiff(sdata))) { 842 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 843 return; 844 } 845 846 preq_node = list_first_entry(&ifmsh->preq_queue.list, 847 struct mesh_preq_queue, list); 848 list_del(&preq_node->list); 849 --ifmsh->preq_queue_len; 850 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 851 852 rcu_read_lock(); 853 mpath = mesh_path_lookup(preq_node->dst, sdata); 854 if (!mpath) 855 goto enddiscovery; 856 857 spin_lock_bh(&mpath->state_lock); 858 if (preq_node->flags & PREQ_Q_F_START) { 859 if (mpath->flags & MESH_PATH_RESOLVING) { 860 spin_unlock_bh(&mpath->state_lock); 861 goto enddiscovery; 862 } else { 863 mpath->flags &= ~MESH_PATH_RESOLVED; 864 mpath->flags |= MESH_PATH_RESOLVING; 865 mpath->discovery_retries = 0; 866 mpath->discovery_timeout = disc_timeout_jiff(sdata); 867 } 868 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 869 mpath->flags & MESH_PATH_RESOLVED) { 870 mpath->flags &= ~MESH_PATH_RESOLVING; 871 spin_unlock_bh(&mpath->state_lock); 872 goto enddiscovery; 873 } 874 875 ifmsh->last_preq = jiffies; 876 877 if (time_after(jiffies, ifmsh->last_sn_update + 878 net_traversal_jiffies(sdata)) || 879 time_before(jiffies, ifmsh->last_sn_update)) { 880 ++ifmsh->sn; 881 sdata->u.mesh.last_sn_update = jiffies; 882 } 883 lifetime = default_lifetime(sdata); 884 ttl = sdata->u.mesh.mshcfg.element_ttl; 885 if (ttl == 0) { 886 sdata->u.mesh.mshstats.dropped_frames_ttl++; 887 spin_unlock_bh(&mpath->state_lock); 888 goto enddiscovery; 889 } 890 891 if (preq_node->flags & PREQ_Q_F_REFRESH) 892 target_flags = MP_F_DO; 893 else 894 target_flags = MP_F_RF; 895 896 spin_unlock_bh(&mpath->state_lock); 897 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, 898 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst, 899 cpu_to_le32(mpath->sn), broadcast_addr, 0, 900 ttl, cpu_to_le32(lifetime), 0, 901 cpu_to_le32(ifmsh->preq_id++), sdata); 902 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 903 904 enddiscovery: 905 rcu_read_unlock(); 906 kfree(preq_node); 907 } 908 909 /** 910 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame 911 * 912 * @skb: 802.11 frame to be sent 913 * @sdata: network subif the frame will be sent through 914 * 915 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is 916 * found, the function will start a path discovery and queue the frame so it is 917 * sent when the path is resolved. This means the caller must not free the skb 918 * in this case. 919 */ 920 int mesh_nexthop_lookup(struct sk_buff *skb, 921 struct ieee80211_sub_if_data *sdata) 922 { 923 struct sk_buff *skb_to_free = NULL; 924 struct mesh_path *mpath; 925 struct sta_info *next_hop; 926 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 927 u8 *target_addr = hdr->addr3; 928 int err = 0; 929 930 rcu_read_lock(); 931 mpath = mesh_path_lookup(target_addr, sdata); 932 933 if (!mpath) { 934 mesh_path_add(target_addr, sdata); 935 mpath = mesh_path_lookup(target_addr, sdata); 936 if (!mpath) { 937 sdata->u.mesh.mshstats.dropped_frames_no_route++; 938 err = -ENOSPC; 939 goto endlookup; 940 } 941 } 942 943 if (mpath->flags & MESH_PATH_ACTIVE) { 944 if (time_after(jiffies, 945 mpath->exp_time - 946 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && 947 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) && 948 !(mpath->flags & MESH_PATH_RESOLVING) && 949 !(mpath->flags & MESH_PATH_FIXED)) { 950 mesh_queue_preq(mpath, 951 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 952 } 953 next_hop = rcu_dereference(mpath->next_hop); 954 if (next_hop) 955 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); 956 else 957 err = -ENOENT; 958 } else { 959 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 960 if (!(mpath->flags & MESH_PATH_RESOLVING)) { 961 /* Start discovery only if it is not running yet */ 962 mesh_queue_preq(mpath, PREQ_Q_F_START); 963 } 964 965 if (skb_queue_len(&mpath->frame_queue) >= 966 MESH_FRAME_QUEUE_LEN) 967 skb_to_free = skb_dequeue(&mpath->frame_queue); 968 969 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 970 skb_queue_tail(&mpath->frame_queue, skb); 971 if (skb_to_free) 972 mesh_path_discard_frame(skb_to_free, sdata); 973 err = -ENOENT; 974 } 975 976 endlookup: 977 rcu_read_unlock(); 978 return err; 979 } 980 981 void mesh_path_timer(unsigned long data) 982 { 983 struct mesh_path *mpath = (void *) data; 984 struct ieee80211_sub_if_data *sdata = mpath->sdata; 985 986 if (sdata->local->quiescing) 987 return; 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 } 1005 1006 void 1007 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) 1008 { 1009 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 1010 1011 mesh_path_sel_frame_tx(MPATH_RANN, 0, sdata->vif.addr, 1012 cpu_to_le32(++ifmsh->sn), 1013 0, NULL, 0, broadcast_addr, 1014 0, sdata->u.mesh.mshcfg.element_ttl, 1015 0, 0, 0, sdata); 1016 } 1017