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 TU_TO_EXP_TIME(x) (jiffies + msecs_to_jiffies(x * 1024 / 1000)) 62 #define MSEC_TO_TU(x) (x*1000/1024) 63 #define DSN_GT(x, y) ((long) (y) - (long) (x) < 0) 64 #define DSN_LT(x, y) ((long) (x) - (long) (y) < 0) 65 66 #define net_traversal_jiffies(s) \ 67 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) 68 #define default_lifetime(s) \ 69 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) 70 #define min_preq_int_jiff(s) \ 71 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) 72 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) 73 #define disc_timeout_jiff(s) \ 74 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) 75 76 enum mpath_frame_type { 77 MPATH_PREQ = 0, 78 MPATH_PREP, 79 MPATH_PERR 80 }; 81 82 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, 83 u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst, 84 __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime, 85 __le32 metric, __le32 preq_id, struct ieee80211_sub_if_data *sdata) 86 { 87 struct ieee80211_local *local = sdata->local; 88 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 89 struct ieee80211_mgmt *mgmt; 90 u8 *pos; 91 int ie_len; 92 93 if (!skb) 94 return -1; 95 skb_reserve(skb, local->hw.extra_tx_headroom); 96 /* 25 is the size of the common mgmt part (24) plus the size of the 97 * common action part (1) 98 */ 99 mgmt = (struct ieee80211_mgmt *) 100 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 101 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 102 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 103 IEEE80211_STYPE_ACTION); 104 105 memcpy(mgmt->da, da, ETH_ALEN); 106 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 107 /* BSSID is left zeroed, wildcard value */ 108 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; 109 mgmt->u.action.u.mesh_action.action_code = action; 110 111 switch (action) { 112 case MPATH_PREQ: 113 ie_len = 37; 114 pos = skb_put(skb, 2 + ie_len); 115 *pos++ = WLAN_EID_PREQ; 116 break; 117 case MPATH_PREP: 118 ie_len = 31; 119 pos = skb_put(skb, 2 + ie_len); 120 *pos++ = WLAN_EID_PREP; 121 break; 122 default: 123 kfree_skb(skb); 124 return -ENOTSUPP; 125 break; 126 } 127 *pos++ = ie_len; 128 *pos++ = flags; 129 *pos++ = hop_count; 130 *pos++ = ttl; 131 if (action == MPATH_PREQ) { 132 memcpy(pos, &preq_id, 4); 133 pos += 4; 134 } 135 memcpy(pos, orig_addr, ETH_ALEN); 136 pos += ETH_ALEN; 137 memcpy(pos, &orig_dsn, 4); 138 pos += 4; 139 memcpy(pos, &lifetime, 4); 140 pos += 4; 141 memcpy(pos, &metric, 4); 142 pos += 4; 143 if (action == MPATH_PREQ) { 144 /* destination count */ 145 *pos++ = 1; 146 *pos++ = dst_flags; 147 } 148 memcpy(pos, dst, ETH_ALEN); 149 pos += ETH_ALEN; 150 memcpy(pos, &dst_dsn, 4); 151 152 ieee80211_tx_skb(sdata, skb, 0); 153 return 0; 154 } 155 156 /** 157 * mesh_send_path error - Sends a PERR mesh management frame 158 * 159 * @dst: broken destination 160 * @dst_dsn: dsn of the broken destination 161 * @ra: node this frame is addressed to 162 */ 163 int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra, 164 struct ieee80211_sub_if_data *sdata) 165 { 166 struct ieee80211_local *local = sdata->local; 167 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 168 struct ieee80211_mgmt *mgmt; 169 u8 *pos; 170 int ie_len; 171 172 if (!skb) 173 return -1; 174 skb_reserve(skb, local->hw.extra_tx_headroom); 175 /* 25 is the size of the common mgmt part (24) plus the size of the 176 * common action part (1) 177 */ 178 mgmt = (struct ieee80211_mgmt *) 179 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); 180 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); 181 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 182 IEEE80211_STYPE_ACTION); 183 184 memcpy(mgmt->da, ra, ETH_ALEN); 185 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 186 /* BSSID is left zeroed, wildcard value */ 187 mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; 188 mgmt->u.action.u.mesh_action.action_code = MPATH_PERR; 189 ie_len = 12; 190 pos = skb_put(skb, 2 + ie_len); 191 *pos++ = WLAN_EID_PERR; 192 *pos++ = ie_len; 193 /* mode flags, reserved */ 194 *pos++ = 0; 195 /* number of destinations */ 196 *pos++ = 1; 197 memcpy(pos, dst, ETH_ALEN); 198 pos += ETH_ALEN; 199 memcpy(pos, &dst_dsn, 4); 200 201 ieee80211_tx_skb(sdata, skb, 0); 202 return 0; 203 } 204 205 static u32 airtime_link_metric_get(struct ieee80211_local *local, 206 struct sta_info *sta) 207 { 208 struct ieee80211_supported_band *sband; 209 /* This should be adjusted for each device */ 210 int device_constant = 1 << ARITH_SHIFT; 211 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 212 int s_unit = 1 << ARITH_SHIFT; 213 int rate, err; 214 u32 tx_time, estimated_retx; 215 u64 result; 216 217 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 218 219 if (sta->fail_avg >= 100) 220 return MAX_METRIC; 221 err = (sta->fail_avg << ARITH_SHIFT) / 100; 222 223 /* bitrate is in units of 100 Kbps, while we need rate in units of 224 * 1Mbps. This will be corrected on tx_time computation. 225 */ 226 rate = sband->bitrates[sta->last_txrate_idx].bitrate; 227 tx_time = (device_constant + 10 * test_frame_len / rate); 228 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 229 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 230 return (u32)result; 231 } 232 233 /** 234 * hwmp_route_info_get - Update routing info to originator and transmitter 235 * 236 * @sdata: local mesh subif 237 * @mgmt: mesh management frame 238 * @hwmp_ie: hwmp information element (PREP or PREQ) 239 * 240 * This function updates the path routing information to the originator and the 241 * transmitter of a HWMP PREQ or PREP fram. 242 * 243 * Returns: metric to frame originator or 0 if the frame should not be further 244 * processed 245 * 246 * Notes: this function is the only place (besides user-provided info) where 247 * path routing information is updated. 248 */ 249 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 250 struct ieee80211_mgmt *mgmt, 251 u8 *hwmp_ie) 252 { 253 struct ieee80211_local *local = sdata->local; 254 struct mesh_path *mpath; 255 struct sta_info *sta; 256 bool fresh_info; 257 u8 *orig_addr, *ta; 258 u32 orig_dsn, orig_metric; 259 unsigned long orig_lifetime, exp_time; 260 u32 last_hop_metric, new_metric; 261 bool process = true; 262 u8 action = mgmt->u.action.u.mesh_action.action_code; 263 264 rcu_read_lock(); 265 sta = sta_info_get(local, mgmt->sa); 266 if (!sta) { 267 rcu_read_unlock(); 268 return 0; 269 } 270 271 last_hop_metric = airtime_link_metric_get(local, sta); 272 /* Update and check originator routing info */ 273 fresh_info = true; 274 275 switch (action) { 276 case MPATH_PREQ: 277 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 278 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie); 279 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 280 orig_metric = PREQ_IE_METRIC(hwmp_ie); 281 break; 282 case MPATH_PREP: 283 /* Originator here refers to the MP that was the destination in 284 * the Path Request. The draft refers to that MP as the 285 * destination address, even though usually it is the origin of 286 * the PREP frame. We divert from the nomenclature in the draft 287 * so that we can easily use a single function to gather path 288 * information from both PREQ and PREP frames. 289 */ 290 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie); 291 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie); 292 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 293 orig_metric = PREP_IE_METRIC(hwmp_ie); 294 break; 295 default: 296 rcu_read_unlock(); 297 return 0; 298 } 299 new_metric = orig_metric + last_hop_metric; 300 if (new_metric < orig_metric) 301 new_metric = MAX_METRIC; 302 exp_time = TU_TO_EXP_TIME(orig_lifetime); 303 304 if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 305 /* This MP is the originator, we are not interested in this 306 * frame, except for updating transmitter's path info. 307 */ 308 process = false; 309 fresh_info = false; 310 } else { 311 mpath = mesh_path_lookup(orig_addr, sdata); 312 if (mpath) { 313 spin_lock_bh(&mpath->state_lock); 314 if (mpath->flags & MESH_PATH_FIXED) 315 fresh_info = false; 316 else if ((mpath->flags & MESH_PATH_ACTIVE) && 317 (mpath->flags & MESH_PATH_DSN_VALID)) { 318 if (DSN_GT(mpath->dsn, orig_dsn) || 319 (mpath->dsn == orig_dsn && 320 action == MPATH_PREQ && 321 new_metric > mpath->metric)) { 322 process = false; 323 fresh_info = false; 324 } 325 } 326 } else { 327 mesh_path_add(orig_addr, sdata); 328 mpath = mesh_path_lookup(orig_addr, sdata); 329 if (!mpath) { 330 rcu_read_unlock(); 331 return 0; 332 } 333 spin_lock_bh(&mpath->state_lock); 334 } 335 336 if (fresh_info) { 337 mesh_path_assign_nexthop(mpath, sta); 338 mpath->flags |= MESH_PATH_DSN_VALID; 339 mpath->metric = new_metric; 340 mpath->dsn = orig_dsn; 341 mpath->exp_time = time_after(mpath->exp_time, exp_time) 342 ? mpath->exp_time : exp_time; 343 mesh_path_activate(mpath); 344 spin_unlock_bh(&mpath->state_lock); 345 mesh_path_tx_pending(mpath); 346 /* draft says preq_id should be saved to, but there does 347 * not seem to be any use for it, skipping by now 348 */ 349 } else 350 spin_unlock_bh(&mpath->state_lock); 351 } 352 353 /* Update and check transmitter routing info */ 354 ta = mgmt->sa; 355 if (memcmp(orig_addr, ta, ETH_ALEN) == 0) 356 fresh_info = false; 357 else { 358 fresh_info = true; 359 360 mpath = mesh_path_lookup(ta, sdata); 361 if (mpath) { 362 spin_lock_bh(&mpath->state_lock); 363 if ((mpath->flags & MESH_PATH_FIXED) || 364 ((mpath->flags & MESH_PATH_ACTIVE) && 365 (last_hop_metric > mpath->metric))) 366 fresh_info = false; 367 } else { 368 mesh_path_add(ta, sdata); 369 mpath = mesh_path_lookup(ta, sdata); 370 if (!mpath) { 371 rcu_read_unlock(); 372 return 0; 373 } 374 spin_lock_bh(&mpath->state_lock); 375 } 376 377 if (fresh_info) { 378 mesh_path_assign_nexthop(mpath, sta); 379 mpath->flags &= ~MESH_PATH_DSN_VALID; 380 mpath->metric = last_hop_metric; 381 mpath->exp_time = time_after(mpath->exp_time, exp_time) 382 ? mpath->exp_time : exp_time; 383 mesh_path_activate(mpath); 384 spin_unlock_bh(&mpath->state_lock); 385 mesh_path_tx_pending(mpath); 386 } else 387 spin_unlock_bh(&mpath->state_lock); 388 } 389 390 rcu_read_unlock(); 391 392 return process ? new_metric : 0; 393 } 394 395 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 396 struct ieee80211_mgmt *mgmt, 397 u8 *preq_elem, u32 metric) { 398 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 399 struct mesh_path *mpath; 400 u8 *dst_addr, *orig_addr; 401 u8 dst_flags, ttl; 402 u32 orig_dsn, dst_dsn, lifetime; 403 bool reply = false; 404 bool forward = true; 405 406 /* Update destination DSN, if present */ 407 dst_addr = PREQ_IE_DST_ADDR(preq_elem); 408 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 409 dst_dsn = PREQ_IE_DST_DSN(preq_elem); 410 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem); 411 dst_flags = PREQ_IE_DST_F(preq_elem); 412 413 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 414 forward = false; 415 reply = true; 416 metric = 0; 417 if (time_after(jiffies, ifmsh->last_dsn_update + 418 net_traversal_jiffies(sdata)) || 419 time_before(jiffies, ifmsh->last_dsn_update)) { 420 dst_dsn = ++ifmsh->dsn; 421 ifmsh->last_dsn_update = jiffies; 422 } 423 } else { 424 rcu_read_lock(); 425 mpath = mesh_path_lookup(dst_addr, sdata); 426 if (mpath) { 427 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) || 428 DSN_LT(mpath->dsn, dst_dsn)) { 429 mpath->dsn = dst_dsn; 430 mpath->flags &= MESH_PATH_DSN_VALID; 431 } else if ((!(dst_flags & MP_F_DO)) && 432 (mpath->flags & MESH_PATH_ACTIVE)) { 433 reply = true; 434 metric = mpath->metric; 435 dst_dsn = mpath->dsn; 436 if (dst_flags & MP_F_RF) 437 dst_flags |= MP_F_DO; 438 else 439 forward = false; 440 } 441 } 442 rcu_read_unlock(); 443 } 444 445 if (reply) { 446 lifetime = PREQ_IE_LIFETIME(preq_elem); 447 ttl = ifmsh->mshcfg.dot11MeshTTL; 448 if (ttl != 0) 449 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr, 450 cpu_to_le32(dst_dsn), 0, orig_addr, 451 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl, 452 cpu_to_le32(lifetime), cpu_to_le32(metric), 453 0, sdata); 454 else 455 ifmsh->mshstats.dropped_frames_ttl++; 456 } 457 458 if (forward) { 459 u32 preq_id; 460 u8 hopcount, flags; 461 462 ttl = PREQ_IE_TTL(preq_elem); 463 lifetime = PREQ_IE_LIFETIME(preq_elem); 464 if (ttl <= 1) { 465 ifmsh->mshstats.dropped_frames_ttl++; 466 return; 467 } 468 --ttl; 469 flags = PREQ_IE_FLAGS(preq_elem); 470 preq_id = PREQ_IE_PREQ_ID(preq_elem); 471 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 472 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 473 cpu_to_le32(orig_dsn), dst_flags, dst_addr, 474 cpu_to_le32(dst_dsn), sdata->dev->broadcast, 475 hopcount, ttl, cpu_to_le32(lifetime), 476 cpu_to_le32(metric), cpu_to_le32(preq_id), 477 sdata); 478 ifmsh->mshstats.fwded_frames++; 479 } 480 } 481 482 483 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 484 struct ieee80211_mgmt *mgmt, 485 u8 *prep_elem, u32 metric) 486 { 487 struct mesh_path *mpath; 488 u8 *dst_addr, *orig_addr; 489 u8 ttl, hopcount, flags; 490 u8 next_hop[ETH_ALEN]; 491 u32 dst_dsn, orig_dsn, lifetime; 492 493 /* Note that we divert from the draft nomenclature and denominate 494 * destination to what the draft refers to as origininator. So in this 495 * function destnation refers to the final destination of the PREP, 496 * which corresponds with the originator of the PREQ which this PREP 497 * replies 498 */ 499 dst_addr = PREP_IE_DST_ADDR(prep_elem); 500 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) 501 /* destination, no forwarding required */ 502 return; 503 504 ttl = PREP_IE_TTL(prep_elem); 505 if (ttl <= 1) { 506 sdata->u.mesh.mshstats.dropped_frames_ttl++; 507 return; 508 } 509 510 rcu_read_lock(); 511 mpath = mesh_path_lookup(dst_addr, sdata); 512 if (mpath) 513 spin_lock_bh(&mpath->state_lock); 514 else 515 goto fail; 516 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 517 spin_unlock_bh(&mpath->state_lock); 518 goto fail; 519 } 520 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN); 521 spin_unlock_bh(&mpath->state_lock); 522 --ttl; 523 flags = PREP_IE_FLAGS(prep_elem); 524 lifetime = PREP_IE_LIFETIME(prep_elem); 525 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 526 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 527 dst_dsn = PREP_IE_DST_DSN(prep_elem); 528 orig_dsn = PREP_IE_ORIG_DSN(prep_elem); 529 530 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 531 cpu_to_le32(orig_dsn), 0, dst_addr, 532 cpu_to_le32(dst_dsn), mpath->next_hop->sta.addr, hopcount, ttl, 533 cpu_to_le32(lifetime), cpu_to_le32(metric), 534 0, sdata); 535 rcu_read_unlock(); 536 sdata->u.mesh.mshstats.fwded_frames++; 537 return; 538 539 fail: 540 rcu_read_unlock(); 541 sdata->u.mesh.mshstats.dropped_frames_no_route++; 542 return; 543 } 544 545 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 546 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 547 { 548 struct mesh_path *mpath; 549 u8 *ta, *dst_addr; 550 u32 dst_dsn; 551 552 ta = mgmt->sa; 553 dst_addr = PERR_IE_DST_ADDR(perr_elem); 554 dst_dsn = PERR_IE_DST_DSN(perr_elem); 555 rcu_read_lock(); 556 mpath = mesh_path_lookup(dst_addr, sdata); 557 if (mpath) { 558 spin_lock_bh(&mpath->state_lock); 559 if (mpath->flags & MESH_PATH_ACTIVE && 560 memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 && 561 (!(mpath->flags & MESH_PATH_DSN_VALID) || 562 DSN_GT(dst_dsn, mpath->dsn))) { 563 mpath->flags &= ~MESH_PATH_ACTIVE; 564 mpath->dsn = dst_dsn; 565 spin_unlock_bh(&mpath->state_lock); 566 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn), 567 sdata->dev->broadcast, sdata); 568 } else 569 spin_unlock_bh(&mpath->state_lock); 570 } 571 rcu_read_unlock(); 572 } 573 574 575 576 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 577 struct ieee80211_mgmt *mgmt, 578 size_t len) 579 { 580 struct ieee802_11_elems elems; 581 size_t baselen; 582 u32 last_hop_metric; 583 584 /* need action_code */ 585 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 586 return; 587 588 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 589 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 590 len - baselen, &elems); 591 592 switch (mgmt->u.action.u.mesh_action.action_code) { 593 case MPATH_PREQ: 594 if (!elems.preq || elems.preq_len != 37) 595 /* Right now we support just 1 destination and no AE */ 596 return; 597 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq); 598 if (!last_hop_metric) 599 return; 600 hwmp_preq_frame_process(sdata, mgmt, elems.preq, last_hop_metric); 601 break; 602 case MPATH_PREP: 603 if (!elems.prep || elems.prep_len != 31) 604 /* Right now we support no AE */ 605 return; 606 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep); 607 if (!last_hop_metric) 608 return; 609 hwmp_prep_frame_process(sdata, mgmt, elems.prep, last_hop_metric); 610 break; 611 case MPATH_PERR: 612 if (!elems.perr || elems.perr_len != 12) 613 /* Right now we support only one destination per PERR */ 614 return; 615 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 616 default: 617 return; 618 } 619 620 } 621 622 /** 623 * mesh_queue_preq - queue a PREQ to a given destination 624 * 625 * @mpath: mesh path to discover 626 * @flags: special attributes of the PREQ to be sent 627 * 628 * Locking: the function must be called from within a rcu read lock block. 629 * 630 */ 631 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 632 { 633 struct ieee80211_sub_if_data *sdata = mpath->sdata; 634 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 635 struct mesh_preq_queue *preq_node; 636 637 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_KERNEL); 638 if (!preq_node) { 639 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n"); 640 return; 641 } 642 643 spin_lock(&ifmsh->mesh_preq_queue_lock); 644 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 645 spin_unlock(&ifmsh->mesh_preq_queue_lock); 646 kfree(preq_node); 647 if (printk_ratelimit()) 648 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n"); 649 return; 650 } 651 652 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 653 preq_node->flags = flags; 654 655 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 656 ++ifmsh->preq_queue_len; 657 spin_unlock(&ifmsh->mesh_preq_queue_lock); 658 659 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 660 queue_work(sdata->local->hw.workqueue, &ifmsh->work); 661 662 else if (time_before(jiffies, ifmsh->last_preq)) { 663 /* avoid long wait if did not send preqs for a long time 664 * and jiffies wrapped around 665 */ 666 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 667 queue_work(sdata->local->hw.workqueue, &ifmsh->work); 668 } else 669 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 670 min_preq_int_jiff(sdata)); 671 } 672 673 /** 674 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 675 * 676 * @sdata: local mesh subif 677 */ 678 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 679 { 680 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 681 struct mesh_preq_queue *preq_node; 682 struct mesh_path *mpath; 683 u8 ttl, dst_flags; 684 u32 lifetime; 685 686 spin_lock(&ifmsh->mesh_preq_queue_lock); 687 if (!ifmsh->preq_queue_len || 688 time_before(jiffies, ifmsh->last_preq + 689 min_preq_int_jiff(sdata))) { 690 spin_unlock(&ifmsh->mesh_preq_queue_lock); 691 return; 692 } 693 694 preq_node = list_first_entry(&ifmsh->preq_queue.list, 695 struct mesh_preq_queue, list); 696 list_del(&preq_node->list); 697 --ifmsh->preq_queue_len; 698 spin_unlock(&ifmsh->mesh_preq_queue_lock); 699 700 rcu_read_lock(); 701 mpath = mesh_path_lookup(preq_node->dst, sdata); 702 if (!mpath) 703 goto enddiscovery; 704 705 spin_lock_bh(&mpath->state_lock); 706 if (preq_node->flags & PREQ_Q_F_START) { 707 if (mpath->flags & MESH_PATH_RESOLVING) { 708 spin_unlock_bh(&mpath->state_lock); 709 goto enddiscovery; 710 } else { 711 mpath->flags &= ~MESH_PATH_RESOLVED; 712 mpath->flags |= MESH_PATH_RESOLVING; 713 mpath->discovery_retries = 0; 714 mpath->discovery_timeout = disc_timeout_jiff(sdata); 715 } 716 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 717 mpath->flags & MESH_PATH_RESOLVED) { 718 mpath->flags &= ~MESH_PATH_RESOLVING; 719 spin_unlock_bh(&mpath->state_lock); 720 goto enddiscovery; 721 } 722 723 ifmsh->last_preq = jiffies; 724 725 if (time_after(jiffies, ifmsh->last_dsn_update + 726 net_traversal_jiffies(sdata)) || 727 time_before(jiffies, ifmsh->last_dsn_update)) { 728 ++ifmsh->dsn; 729 sdata->u.mesh.last_dsn_update = jiffies; 730 } 731 lifetime = default_lifetime(sdata); 732 ttl = sdata->u.mesh.mshcfg.dot11MeshTTL; 733 if (ttl == 0) { 734 sdata->u.mesh.mshstats.dropped_frames_ttl++; 735 spin_unlock_bh(&mpath->state_lock); 736 goto enddiscovery; 737 } 738 739 if (preq_node->flags & PREQ_Q_F_REFRESH) 740 dst_flags = MP_F_DO; 741 else 742 dst_flags = MP_F_RF; 743 744 spin_unlock_bh(&mpath->state_lock); 745 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->dev->dev_addr, 746 cpu_to_le32(ifmsh->dsn), dst_flags, mpath->dst, 747 cpu_to_le32(mpath->dsn), sdata->dev->broadcast, 0, 748 ttl, cpu_to_le32(lifetime), 0, 749 cpu_to_le32(ifmsh->preq_id++), sdata); 750 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 751 752 enddiscovery: 753 rcu_read_unlock(); 754 kfree(preq_node); 755 } 756 757 /** 758 * ieee80211s_lookup_nexthop - put the appropriate next hop on a mesh frame 759 * 760 * @skb: 802.11 frame to be sent 761 * @sdata: network subif the frame will be sent through 762 * @fwd_frame: true if this frame was originally from a different host 763 * 764 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is 765 * found, the function will start a path discovery and queue the frame so it is 766 * sent when the path is resolved. This means the caller must not free the skb 767 * in this case. 768 */ 769 int mesh_nexthop_lookup(struct sk_buff *skb, 770 struct ieee80211_sub_if_data *sdata) 771 { 772 struct sk_buff *skb_to_free = NULL; 773 struct mesh_path *mpath; 774 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 775 u8 *dst_addr = hdr->addr3; 776 int err = 0; 777 778 rcu_read_lock(); 779 mpath = mesh_path_lookup(dst_addr, sdata); 780 781 if (!mpath) { 782 mesh_path_add(dst_addr, sdata); 783 mpath = mesh_path_lookup(dst_addr, sdata); 784 if (!mpath) { 785 dev_kfree_skb(skb); 786 sdata->u.mesh.mshstats.dropped_frames_no_route++; 787 err = -ENOSPC; 788 goto endlookup; 789 } 790 } 791 792 if (mpath->flags & MESH_PATH_ACTIVE) { 793 if (time_after(jiffies, mpath->exp_time - 794 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) 795 && !memcmp(sdata->dev->dev_addr, hdr->addr4, 796 ETH_ALEN) 797 && !(mpath->flags & MESH_PATH_RESOLVING) 798 && !(mpath->flags & MESH_PATH_FIXED)) { 799 mesh_queue_preq(mpath, 800 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 801 } 802 memcpy(hdr->addr1, mpath->next_hop->sta.addr, 803 ETH_ALEN); 804 } else { 805 if (!(mpath->flags & MESH_PATH_RESOLVING)) { 806 /* Start discovery only if it is not running yet */ 807 mesh_queue_preq(mpath, PREQ_Q_F_START); 808 } 809 810 if (skb_queue_len(&mpath->frame_queue) >= 811 MESH_FRAME_QUEUE_LEN) { 812 skb_to_free = mpath->frame_queue.next; 813 skb_unlink(skb_to_free, &mpath->frame_queue); 814 } 815 816 skb_queue_tail(&mpath->frame_queue, skb); 817 if (skb_to_free) 818 mesh_path_discard_frame(skb_to_free, sdata); 819 err = -ENOENT; 820 } 821 822 endlookup: 823 rcu_read_unlock(); 824 return err; 825 } 826 827 void mesh_path_timer(unsigned long data) 828 { 829 struct ieee80211_sub_if_data *sdata; 830 struct mesh_path *mpath; 831 832 rcu_read_lock(); 833 mpath = (struct mesh_path *) data; 834 mpath = rcu_dereference(mpath); 835 if (!mpath) 836 goto endmpathtimer; 837 spin_lock_bh(&mpath->state_lock); 838 sdata = mpath->sdata; 839 if (mpath->flags & MESH_PATH_RESOLVED || 840 (!(mpath->flags & MESH_PATH_RESOLVING))) 841 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 842 else if (mpath->discovery_retries < max_preq_retries(sdata)) { 843 ++mpath->discovery_retries; 844 mpath->discovery_timeout *= 2; 845 mesh_queue_preq(mpath, 0); 846 } else { 847 mpath->flags = 0; 848 mpath->exp_time = jiffies; 849 mesh_path_flush_pending(mpath); 850 } 851 852 spin_unlock_bh(&mpath->state_lock); 853 endmpathtimer: 854 rcu_read_unlock(); 855 } 856