1 /* 2 * Copyright (c) 2008 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 #define TEST_FRAME_LEN 8192 13 #define MAX_METRIC 0xffffffff 14 #define ARITH_SHIFT 8 15 16 /* Number of frames buffered per destination for unresolved destinations */ 17 #define MESH_FRAME_QUEUE_LEN 10 18 #define MAX_PREQ_QUEUE_LEN 64 19 20 /* Destination only */ 21 #define MP_F_DO 0x1 22 /* Reply and forward */ 23 #define MP_F_RF 0x2 24 25 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae) 26 { 27 if (ae) 28 offset += 6; 29 return get_unaligned_le32(preq_elem + offset); 30 } 31 32 /* HWMP IE processing macros */ 33 #define AE_F (1<<6) 34 #define AE_F_SET(x) (*x & AE_F) 35 #define PREQ_IE_FLAGS(x) (*(x)) 36 #define PREQ_IE_HOPCOUNT(x) (*(x + 1)) 37 #define PREQ_IE_TTL(x) (*(x + 2)) 38 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0) 39 #define PREQ_IE_ORIG_ADDR(x) (x + 7) 40 #define PREQ_IE_ORIG_DSN(x) u32_field_get(x, 13, 0); 41 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)); 42 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)); 43 #define PREQ_IE_DST_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) 44 #define PREQ_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) 45 #define PREQ_IE_DST_DSN(x) u32_field_get(x, 33, AE_F_SET(x)); 46 47 48 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) 49 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) 50 #define PREP_IE_TTL(x) PREQ_IE_TTL(x) 51 #define PREP_IE_ORIG_ADDR(x) (x + 3) 52 #define PREP_IE_ORIG_DSN(x) u32_field_get(x, 9, 0); 53 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)); 54 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)); 55 #define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) 56 #define PREP_IE_DST_DSN(x) u32_field_get(x, 27, AE_F_SET(x)); 57 58 #define PERR_IE_DST_ADDR(x) (x + 2) 59 #define PERR_IE_DST_DSN(x) u32_field_get(x, 8, 0); 60 61 #define MSEC_TO_TU(x) (x*1000/1024) 62 #define DSN_GT(x, y) ((long) (y) - (long) (x) < 0) 63 #define DSN_LT(x, y) ((long) (x) - (long) (y) < 0) 64 65 #define net_traversal_jiffies(s) \ 66 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 67 #define default_lifetime(s) \ 68 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 69 #define min_preq_int_jiff(s) \ 70 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 71 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 72 #define disc_timeout_jiff(s) \ 73 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 74 75 enum mpath_frame_type { 76 MPATH_PREQ = 0, 77 MPATH_PREP, 78 MPATH_PERR 79 }; 80 81 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 82 u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst, 83 __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime, 84 __le32 metric, __le32 preq_id, struct ieee80211_sub_if_data *sdata) 85 { 86 struct ieee80211_local *local = sdata->local; 87 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 88 struct ieee80211_mgmt *mgmt; 89 u8 *pos; 90 int ie_len; 91 92 if (!skb) 93 return -1; 94 skb_reserve(skb, local->hw.extra_tx_headroom); 95 /* 25 is the size of the common mgmt part (24) plus the size of the 96 * common action part (1) 97 */ 98 mgmt = (struct ieee80211_mgmt *) 99 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 100 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 101 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 102 IEEE80211_STYPE_ACTION); 103 104 memcpy(mgmt->da, da, ETH_ALEN); 105 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 106 /* BSSID is left zeroed, wildcard value */ 107 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; 108 mgmt->u.action.u.mesh_action.action_code = action; 109 110 switch (action) { 111 case MPATH_PREQ: 112 ie_len = 37; 113 pos = skb_put(skb, 2 + ie_len); 114 *pos++ = WLAN_EID_PREQ; 115 break; 116 case MPATH_PREP: 117 ie_len = 31; 118 pos = skb_put(skb, 2 + ie_len); 119 *pos++ = WLAN_EID_PREP; 120 break; 121 default: 122 kfree_skb(skb); 123 return -ENOTSUPP; 124 break; 125 } 126 *pos++ = ie_len; 127 *pos++ = flags; 128 *pos++ = hop_count; 129 *pos++ = ttl; 130 if (action == MPATH_PREQ) { 131 memcpy(pos, &preq_id, 4); 132 pos += 4; 133 } 134 memcpy(pos, orig_addr, ETH_ALEN); 135 pos += ETH_ALEN; 136 memcpy(pos, &orig_dsn, 4); 137 pos += 4; 138 memcpy(pos, &lifetime, 4); 139 pos += 4; 140 memcpy(pos, &metric, 4); 141 pos += 4; 142 if (action == MPATH_PREQ) { 143 /* destination count */ 144 *pos++ = 1; 145 *pos++ = dst_flags; 146 } 147 memcpy(pos, dst, ETH_ALEN); 148 pos += ETH_ALEN; 149 memcpy(pos, &dst_dsn, 4); 150 151 ieee80211_tx_skb(sdata, skb, 1); 152 return 0; 153 } 154 155 /** 156 * mesh_send_path error - Sends a PERR mesh management frame 157 * 158 * @dst: broken destination 159 * @dst_dsn: dsn of the broken destination 160 * @ra: node this frame is addressed to 161 */ 162 int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra, 163 struct ieee80211_sub_if_data *sdata) 164 { 165 struct ieee80211_local *local = sdata->local; 166 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 167 struct ieee80211_mgmt *mgmt; 168 u8 *pos; 169 int ie_len; 170 171 if (!skb) 172 return -1; 173 skb_reserve(skb, local->hw.extra_tx_headroom); 174 /* 25 is the size of the common mgmt part (24) plus the size of the 175 * common action part (1) 176 */ 177 mgmt = (struct ieee80211_mgmt *) 178 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 179 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 180 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 181 IEEE80211_STYPE_ACTION); 182 183 memcpy(mgmt->da, ra, ETH_ALEN); 184 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 185 /* BSSID is left zeroed, wildcard value */ 186 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; 187 mgmt->u.action.u.mesh_action.action_code = MPATH_PERR; 188 ie_len = 12; 189 pos = skb_put(skb, 2 + ie_len); 190 *pos++ = WLAN_EID_PERR; 191 *pos++ = ie_len; 192 /* mode flags, reserved */ 193 *pos++ = 0; 194 /* number of destinations */ 195 *pos++ = 1; 196 memcpy(pos, dst, ETH_ALEN); 197 pos += ETH_ALEN; 198 memcpy(pos, &dst_dsn, 4); 199 200 ieee80211_tx_skb(sdata, skb, 1); 201 return 0; 202 } 203 204 void ieee80211s_update_metric(struct ieee80211_local *local, 205 struct sta_info *stainfo, struct sk_buff *skb) 206 { 207 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); 208 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 209 int failed; 210 211 if (!ieee80211_is_data(hdr->frame_control)) 212 return; 213 214 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); 215 216 /* moving average, scaled to 100 */ 217 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed); 218 if (stainfo->fail_avg > 95) 219 mesh_plink_broken(stainfo); 220 } 221 222 static u32 airtime_link_metric_get(struct ieee80211_local *local, 223 struct sta_info *sta) 224 { 225 struct ieee80211_supported_band *sband; 226 /* This should be adjusted for each device */ 227 int device_constant = 1 << ARITH_SHIFT; 228 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 229 int s_unit = 1 << ARITH_SHIFT; 230 int rate, err; 231 u32 tx_time, estimated_retx; 232 u64 result; 233 234 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 235 236 if (sta->fail_avg >= 100) 237 return MAX_METRIC; 238 239 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS) 240 return MAX_METRIC; 241 242 err = (sta->fail_avg << ARITH_SHIFT) / 100; 243 244 /* bitrate is in units of 100 Kbps, while we need rate in units of 245 * 1Mbps. This will be corrected on tx_time computation. 246 */ 247 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate; 248 tx_time = (device_constant + 10 * test_frame_len / rate); 249 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 250 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 251 return (u32)result; 252 } 253 254 /** 255 * hwmp_route_info_get - Update routing info to originator and transmitter 256 * 257 * @sdata: local mesh subif 258 * @mgmt: mesh management frame 259 * @hwmp_ie: hwmp information element (PREP or PREQ) 260 * 261 * This function updates the path routing information to the originator and the 262 * transmitter of a HWMP PREQ or PREP fram. 263 * 264 * Returns: metric to frame originator or 0 if the frame should not be further 265 * processed 266 * 267 * Notes: this function is the only place (besides user-provided info) where 268 * path routing information is updated. 269 */ 270 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 271 struct ieee80211_mgmt *mgmt, 272 u8 *hwmp_ie) 273 { 274 struct ieee80211_local *local = sdata->local; 275 struct mesh_path *mpath; 276 struct sta_info *sta; 277 bool fresh_info; 278 u8 *orig_addr, *ta; 279 u32 orig_dsn, orig_metric; 280 unsigned long orig_lifetime, exp_time; 281 u32 last_hop_metric, new_metric; 282 bool process = true; 283 u8 action = mgmt->u.action.u.mesh_action.action_code; 284 285 rcu_read_lock(); 286 sta = sta_info_get(local, mgmt->sa); 287 if (!sta) { 288 rcu_read_unlock(); 289 return 0; 290 } 291 292 last_hop_metric = airtime_link_metric_get(local, sta); 293 /* Update and check originator routing info */ 294 fresh_info = true; 295 296 switch (action) { 297 case MPATH_PREQ: 298 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 299 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie); 300 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 301 orig_metric = PREQ_IE_METRIC(hwmp_ie); 302 break; 303 case MPATH_PREP: 304 /* Originator here refers to the MP that was the destination in 305 * the Path Request. The draft refers to that MP as the 306 * destination address, even though usually it is the origin of 307 * the PREP frame. We divert from the nomenclature in the draft 308 * so that we can easily use a single function to gather path 309 * information from both PREQ and PREP frames. 310 */ 311 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie); 312 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie); 313 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 314 orig_metric = PREP_IE_METRIC(hwmp_ie); 315 break; 316 default: 317 rcu_read_unlock(); 318 return 0; 319 } 320 new_metric = orig_metric + last_hop_metric; 321 if (new_metric < orig_metric) 322 new_metric = MAX_METRIC; 323 exp_time = TU_TO_EXP_TIME(orig_lifetime); 324 325 if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 326 /* This MP is the originator, we are not interested in this 327 * frame, except for updating transmitter's path info. 328 */ 329 process = false; 330 fresh_info = false; 331 } else { 332 mpath = mesh_path_lookup(orig_addr, sdata); 333 if (mpath) { 334 spin_lock_bh(&mpath->state_lock); 335 if (mpath->flags & MESH_PATH_FIXED) 336 fresh_info = false; 337 else if ((mpath->flags & MESH_PATH_ACTIVE) && 338 (mpath->flags & MESH_PATH_DSN_VALID)) { 339 if (DSN_GT(mpath->dsn, orig_dsn) || 340 (mpath->dsn == orig_dsn && 341 action == MPATH_PREQ && 342 new_metric > mpath->metric)) { 343 process = false; 344 fresh_info = false; 345 } 346 } 347 } else { 348 mesh_path_add(orig_addr, sdata); 349 mpath = mesh_path_lookup(orig_addr, sdata); 350 if (!mpath) { 351 rcu_read_unlock(); 352 return 0; 353 } 354 spin_lock_bh(&mpath->state_lock); 355 } 356 357 if (fresh_info) { 358 mesh_path_assign_nexthop(mpath, sta); 359 mpath->flags |= MESH_PATH_DSN_VALID; 360 mpath->metric = new_metric; 361 mpath->dsn = orig_dsn; 362 mpath->exp_time = time_after(mpath->exp_time, exp_time) 363 ? mpath->exp_time : exp_time; 364 mesh_path_activate(mpath); 365 spin_unlock_bh(&mpath->state_lock); 366 mesh_path_tx_pending(mpath); 367 /* draft says preq_id should be saved to, but there does 368 * not seem to be any use for it, skipping by now 369 */ 370 } else 371 spin_unlock_bh(&mpath->state_lock); 372 } 373 374 /* Update and check transmitter routing info */ 375 ta = mgmt->sa; 376 if (memcmp(orig_addr, ta, ETH_ALEN) == 0) 377 fresh_info = false; 378 else { 379 fresh_info = true; 380 381 mpath = mesh_path_lookup(ta, sdata); 382 if (mpath) { 383 spin_lock_bh(&mpath->state_lock); 384 if ((mpath->flags & MESH_PATH_FIXED) || 385 ((mpath->flags & MESH_PATH_ACTIVE) && 386 (last_hop_metric > mpath->metric))) 387 fresh_info = false; 388 } else { 389 mesh_path_add(ta, sdata); 390 mpath = mesh_path_lookup(ta, sdata); 391 if (!mpath) { 392 rcu_read_unlock(); 393 return 0; 394 } 395 spin_lock_bh(&mpath->state_lock); 396 } 397 398 if (fresh_info) { 399 mesh_path_assign_nexthop(mpath, sta); 400 mpath->flags &= ~MESH_PATH_DSN_VALID; 401 mpath->metric = last_hop_metric; 402 mpath->exp_time = time_after(mpath->exp_time, exp_time) 403 ? mpath->exp_time : exp_time; 404 mesh_path_activate(mpath); 405 spin_unlock_bh(&mpath->state_lock); 406 mesh_path_tx_pending(mpath); 407 } else 408 spin_unlock_bh(&mpath->state_lock); 409 } 410 411 rcu_read_unlock(); 412 413 return process ? new_metric : 0; 414 } 415 416 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 417 struct ieee80211_mgmt *mgmt, 418 u8 *preq_elem, u32 metric) 419 { 420 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 421 struct mesh_path *mpath; 422 u8 *dst_addr, *orig_addr; 423 u8 dst_flags, ttl; 424 u32 orig_dsn, dst_dsn, lifetime; 425 bool reply = false; 426 bool forward = true; 427 428 /* Update destination DSN, if present */ 429 dst_addr = PREQ_IE_DST_ADDR(preq_elem); 430 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 431 dst_dsn = PREQ_IE_DST_DSN(preq_elem); 432 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem); 433 dst_flags = PREQ_IE_DST_F(preq_elem); 434 435 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 436 forward = false; 437 reply = true; 438 metric = 0; 439 if (time_after(jiffies, ifmsh->last_dsn_update + 440 net_traversal_jiffies(sdata)) || 441 time_before(jiffies, ifmsh->last_dsn_update)) { 442 dst_dsn = ++ifmsh->dsn; 443 ifmsh->last_dsn_update = jiffies; 444 } 445 } else { 446 rcu_read_lock(); 447 mpath = mesh_path_lookup(dst_addr, sdata); 448 if (mpath) { 449 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) || 450 DSN_LT(mpath->dsn, dst_dsn)) { 451 mpath->dsn = dst_dsn; 452 mpath->flags |= MESH_PATH_DSN_VALID; 453 } else if ((!(dst_flags & MP_F_DO)) && 454 (mpath->flags & MESH_PATH_ACTIVE)) { 455 reply = true; 456 metric = mpath->metric; 457 dst_dsn = mpath->dsn; 458 if (dst_flags & MP_F_RF) 459 dst_flags |= MP_F_DO; 460 else 461 forward = false; 462 } 463 } 464 rcu_read_unlock(); 465 } 466 467 if (reply) { 468 lifetime = PREQ_IE_LIFETIME(preq_elem); 469 ttl = ifmsh->mshcfg.dot11MeshTTL; 470 if (ttl != 0) 471 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr, 472 cpu_to_le32(dst_dsn), 0, orig_addr, 473 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl, 474 cpu_to_le32(lifetime), cpu_to_le32(metric), 475 0, sdata); 476 else 477 ifmsh->mshstats.dropped_frames_ttl++; 478 } 479 480 if (forward) { 481 u32 preq_id; 482 u8 hopcount, flags; 483 484 ttl = PREQ_IE_TTL(preq_elem); 485 lifetime = PREQ_IE_LIFETIME(preq_elem); 486 if (ttl <= 1) { 487 ifmsh->mshstats.dropped_frames_ttl++; 488 return; 489 } 490 --ttl; 491 flags = PREQ_IE_FLAGS(preq_elem); 492 preq_id = PREQ_IE_PREQ_ID(preq_elem); 493 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 494 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 495 cpu_to_le32(orig_dsn), dst_flags, dst_addr, 496 cpu_to_le32(dst_dsn), sdata->dev->broadcast, 497 hopcount, ttl, cpu_to_le32(lifetime), 498 cpu_to_le32(metric), cpu_to_le32(preq_id), 499 sdata); 500 ifmsh->mshstats.fwded_mcast++; 501 ifmsh->mshstats.fwded_frames++; 502 } 503 } 504 505 506 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 507 struct ieee80211_mgmt *mgmt, 508 u8 *prep_elem, u32 metric) 509 { 510 struct mesh_path *mpath; 511 u8 *dst_addr, *orig_addr; 512 u8 ttl, hopcount, flags; 513 u8 next_hop[ETH_ALEN]; 514 u32 dst_dsn, orig_dsn, lifetime; 515 516 /* Note that we divert from the draft nomenclature and denominate 517 * destination to what the draft refers to as origininator. So in this 518 * function destnation refers to the final destination of the PREP, 519 * which corresponds with the originator of the PREQ which this PREP 520 * replies 521 */ 522 dst_addr = PREP_IE_DST_ADDR(prep_elem); 523 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) 524 /* destination, no forwarding required */ 525 return; 526 527 ttl = PREP_IE_TTL(prep_elem); 528 if (ttl <= 1) { 529 sdata->u.mesh.mshstats.dropped_frames_ttl++; 530 return; 531 } 532 533 rcu_read_lock(); 534 mpath = mesh_path_lookup(dst_addr, sdata); 535 if (mpath) 536 spin_lock_bh(&mpath->state_lock); 537 else 538 goto fail; 539 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 540 spin_unlock_bh(&mpath->state_lock); 541 goto fail; 542 } 543 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN); 544 spin_unlock_bh(&mpath->state_lock); 545 --ttl; 546 flags = PREP_IE_FLAGS(prep_elem); 547 lifetime = PREP_IE_LIFETIME(prep_elem); 548 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 549 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 550 dst_dsn = PREP_IE_DST_DSN(prep_elem); 551 orig_dsn = PREP_IE_ORIG_DSN(prep_elem); 552 553 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 554 cpu_to_le32(orig_dsn), 0, dst_addr, 555 cpu_to_le32(dst_dsn), mpath->next_hop->sta.addr, hopcount, ttl, 556 cpu_to_le32(lifetime), cpu_to_le32(metric), 557 0, sdata); 558 rcu_read_unlock(); 559 560 sdata->u.mesh.mshstats.fwded_unicast++; 561 sdata->u.mesh.mshstats.fwded_frames++; 562 return; 563 564 fail: 565 rcu_read_unlock(); 566 sdata->u.mesh.mshstats.dropped_frames_no_route++; 567 return; 568 } 569 570 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 571 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 572 { 573 struct mesh_path *mpath; 574 u8 *ta, *dst_addr; 575 u32 dst_dsn; 576 577 ta = mgmt->sa; 578 dst_addr = PERR_IE_DST_ADDR(perr_elem); 579 dst_dsn = PERR_IE_DST_DSN(perr_elem); 580 rcu_read_lock(); 581 mpath = mesh_path_lookup(dst_addr, sdata); 582 if (mpath) { 583 spin_lock_bh(&mpath->state_lock); 584 if (mpath->flags & MESH_PATH_ACTIVE && 585 memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 && 586 (!(mpath->flags & MESH_PATH_DSN_VALID) || 587 DSN_GT(dst_dsn, mpath->dsn))) { 588 mpath->flags &= ~MESH_PATH_ACTIVE; 589 mpath->dsn = dst_dsn; 590 spin_unlock_bh(&mpath->state_lock); 591 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn), 592 sdata->dev->broadcast, sdata); 593 } else 594 spin_unlock_bh(&mpath->state_lock); 595 } 596 rcu_read_unlock(); 597 } 598 599 600 601 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 602 struct ieee80211_mgmt *mgmt, 603 size_t len) 604 { 605 struct ieee802_11_elems elems; 606 size_t baselen; 607 u32 last_hop_metric; 608 609 /* need action_code */ 610 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 611 return; 612 613 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 614 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 615 len - baselen, &elems); 616 617 switch (mgmt->u.action.u.mesh_action.action_code) { 618 case MPATH_PREQ: 619 if (!elems.preq || elems.preq_len != 37) 620 /* Right now we support just 1 destination and no AE */ 621 return; 622 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq); 623 if (!last_hop_metric) 624 return; 625 hwmp_preq_frame_process(sdata, mgmt, elems.preq, last_hop_metric); 626 break; 627 case MPATH_PREP: 628 if (!elems.prep || elems.prep_len != 31) 629 /* Right now we support no AE */ 630 return; 631 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep); 632 if (!last_hop_metric) 633 return; 634 hwmp_prep_frame_process(sdata, mgmt, elems.prep, last_hop_metric); 635 break; 636 case MPATH_PERR: 637 if (!elems.perr || elems.perr_len != 12) 638 /* Right now we support only one destination per PERR */ 639 return; 640 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 641 default: 642 return; 643 } 644 645 } 646 647 /** 648 * mesh_queue_preq - queue a PREQ to a given destination 649 * 650 * @mpath: mesh path to discover 651 * @flags: special attributes of the PREQ to be sent 652 * 653 * Locking: the function must be called from within a rcu read lock block. 654 * 655 */ 656 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 657 { 658 struct ieee80211_sub_if_data *sdata = mpath->sdata; 659 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 660 struct mesh_preq_queue *preq_node; 661 662 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); 663 if (!preq_node) { 664 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n"); 665 return; 666 } 667 668 spin_lock(&ifmsh->mesh_preq_queue_lock); 669 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 670 spin_unlock(&ifmsh->mesh_preq_queue_lock); 671 kfree(preq_node); 672 if (printk_ratelimit()) 673 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n"); 674 return; 675 } 676 677 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 678 preq_node->flags = flags; 679 680 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 681 ++ifmsh->preq_queue_len; 682 spin_unlock(&ifmsh->mesh_preq_queue_lock); 683 684 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 685 ieee80211_queue_work(&sdata->local->hw, &ifmsh->work); 686 687 else if (time_before(jiffies, ifmsh->last_preq)) { 688 /* avoid long wait if did not send preqs for a long time 689 * and jiffies wrapped around 690 */ 691 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 692 ieee80211_queue_work(&sdata->local->hw, &ifmsh->work); 693 } else 694 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 695 min_preq_int_jiff(sdata)); 696 } 697 698 /** 699 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 700 * 701 * @sdata: local mesh subif 702 */ 703 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 704 { 705 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 706 struct mesh_preq_queue *preq_node; 707 struct mesh_path *mpath; 708 u8 ttl, dst_flags; 709 u32 lifetime; 710 711 spin_lock_bh(&ifmsh->mesh_preq_queue_lock); 712 if (!ifmsh->preq_queue_len || 713 time_before(jiffies, ifmsh->last_preq + 714 min_preq_int_jiff(sdata))) { 715 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 716 return; 717 } 718 719 preq_node = list_first_entry(&ifmsh->preq_queue.list, 720 struct mesh_preq_queue, list); 721 list_del(&preq_node->list); 722 --ifmsh->preq_queue_len; 723 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); 724 725 rcu_read_lock(); 726 mpath = mesh_path_lookup(preq_node->dst, sdata); 727 if (!mpath) 728 goto enddiscovery; 729 730 spin_lock_bh(&mpath->state_lock); 731 if (preq_node->flags & PREQ_Q_F_START) { 732 if (mpath->flags & MESH_PATH_RESOLVING) { 733 spin_unlock_bh(&mpath->state_lock); 734 goto enddiscovery; 735 } else { 736 mpath->flags &= ~MESH_PATH_RESOLVED; 737 mpath->flags |= MESH_PATH_RESOLVING; 738 mpath->discovery_retries = 0; 739 mpath->discovery_timeout = disc_timeout_jiff(sdata); 740 } 741 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 742 mpath->flags & MESH_PATH_RESOLVED) { 743 mpath->flags &= ~MESH_PATH_RESOLVING; 744 spin_unlock_bh(&mpath->state_lock); 745 goto enddiscovery; 746 } 747 748 ifmsh->last_preq = jiffies; 749 750 if (time_after(jiffies, ifmsh->last_dsn_update + 751 net_traversal_jiffies(sdata)) || 752 time_before(jiffies, ifmsh->last_dsn_update)) { 753 ++ifmsh->dsn; 754 sdata->u.mesh.last_dsn_update = jiffies; 755 } 756 lifetime = default_lifetime(sdata); 757 ttl = sdata->u.mesh.mshcfg.dot11MeshTTL; 758 if (ttl == 0) { 759 sdata->u.mesh.mshstats.dropped_frames_ttl++; 760 spin_unlock_bh(&mpath->state_lock); 761 goto enddiscovery; 762 } 763 764 if (preq_node->flags & PREQ_Q_F_REFRESH) 765 dst_flags = MP_F_DO; 766 else 767 dst_flags = MP_F_RF; 768 769 spin_unlock_bh(&mpath->state_lock); 770 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->dev->dev_addr, 771 cpu_to_le32(ifmsh->dsn), dst_flags, mpath->dst, 772 cpu_to_le32(mpath->dsn), sdata->dev->broadcast, 0, 773 ttl, cpu_to_le32(lifetime), 0, 774 cpu_to_le32(ifmsh->preq_id++), sdata); 775 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 776 777 enddiscovery: 778 rcu_read_unlock(); 779 kfree(preq_node); 780 } 781 782 /** 783 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame 784 * 785 * @skb: 802.11 frame to be sent 786 * @sdata: network subif the frame will be sent through 787 * 788 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is 789 * found, the function will start a path discovery and queue the frame so it is 790 * sent when the path is resolved. This means the caller must not free the skb 791 * in this case. 792 */ 793 int mesh_nexthop_lookup(struct sk_buff *skb, 794 struct ieee80211_sub_if_data *sdata) 795 { 796 struct sk_buff *skb_to_free = NULL; 797 struct mesh_path *mpath; 798 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 799 u8 *dst_addr = hdr->addr3; 800 int err = 0; 801 802 rcu_read_lock(); 803 mpath = mesh_path_lookup(dst_addr, sdata); 804 805 if (!mpath) { 806 mesh_path_add(dst_addr, sdata); 807 mpath = mesh_path_lookup(dst_addr, sdata); 808 if (!mpath) { 809 sdata->u.mesh.mshstats.dropped_frames_no_route++; 810 err = -ENOSPC; 811 goto endlookup; 812 } 813 } 814 815 if (mpath->flags & MESH_PATH_ACTIVE) { 816 if (time_after(jiffies, mpath->exp_time + 817 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) 818 && !memcmp(sdata->dev->dev_addr, hdr->addr4, 819 ETH_ALEN) 820 && !(mpath->flags & MESH_PATH_RESOLVING) 821 && !(mpath->flags & MESH_PATH_FIXED)) { 822 mesh_queue_preq(mpath, 823 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 824 } 825 memcpy(hdr->addr1, mpath->next_hop->sta.addr, 826 ETH_ALEN); 827 } else { 828 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 829 if (!(mpath->flags & MESH_PATH_RESOLVING)) { 830 /* Start discovery only if it is not running yet */ 831 mesh_queue_preq(mpath, PREQ_Q_F_START); 832 } 833 834 if (skb_queue_len(&mpath->frame_queue) >= 835 MESH_FRAME_QUEUE_LEN) 836 skb_to_free = skb_dequeue(&mpath->frame_queue); 837 838 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; 839 skb_queue_tail(&mpath->frame_queue, skb); 840 if (skb_to_free) 841 mesh_path_discard_frame(skb_to_free, sdata); 842 err = -ENOENT; 843 } 844 845 endlookup: 846 rcu_read_unlock(); 847 return err; 848 } 849 850 void mesh_path_timer(unsigned long data) 851 { 852 struct ieee80211_sub_if_data *sdata; 853 struct mesh_path *mpath; 854 855 rcu_read_lock(); 856 mpath = (struct mesh_path *) data; 857 mpath = rcu_dereference(mpath); 858 if (!mpath) 859 goto endmpathtimer; 860 sdata = mpath->sdata; 861 862 if (sdata->local->quiescing) { 863 rcu_read_unlock(); 864 return; 865 } 866 867 spin_lock_bh(&mpath->state_lock); 868 if (mpath->flags & MESH_PATH_RESOLVED || 869 (!(mpath->flags & MESH_PATH_RESOLVING))) 870 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 871 else if (mpath->discovery_retries < max_preq_retries(sdata)) { 872 ++mpath->discovery_retries; 873 mpath->discovery_timeout *= 2; 874 mesh_queue_preq(mpath, 0); 875 } else { 876 mpath->flags = 0; 877 mpath->exp_time = jiffies; 878 mesh_path_flush_pending(mpath); 879 } 880 881 spin_unlock_bh(&mpath->state_lock); 882 endmpathtimer: 883 rcu_read_unlock(); 884 } 885