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 static u32 airtime_link_metric_get(struct ieee80211_local *local, 205 struct sta_info *sta) 206 { 207 struct ieee80211_supported_band *sband; 208 /* This should be adjusted for each device */ 209 int device_constant = 1 << ARITH_SHIFT; 210 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; 211 int s_unit = 1 << ARITH_SHIFT; 212 int rate, err; 213 u32 tx_time, estimated_retx; 214 u64 result; 215 216 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 217 218 if (sta->fail_avg >= 100) 219 return MAX_METRIC; 220 221 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS) 222 return MAX_METRIC; 223 224 err = (sta->fail_avg << ARITH_SHIFT) / 100; 225 226 /* bitrate is in units of 100 Kbps, while we need rate in units of 227 * 1Mbps. This will be corrected on tx_time computation. 228 */ 229 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate; 230 tx_time = (device_constant + 10 * test_frame_len / rate); 231 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); 232 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; 233 return (u32)result; 234 } 235 236 /** 237 * hwmp_route_info_get - Update routing info to originator and transmitter 238 * 239 * @sdata: local mesh subif 240 * @mgmt: mesh management frame 241 * @hwmp_ie: hwmp information element (PREP or PREQ) 242 * 243 * This function updates the path routing information to the originator and the 244 * transmitter of a HWMP PREQ or PREP fram. 245 * 246 * Returns: metric to frame originator or 0 if the frame should not be further 247 * processed 248 * 249 * Notes: this function is the only place (besides user-provided info) where 250 * path routing information is updated. 251 */ 252 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, 253 struct ieee80211_mgmt *mgmt, 254 u8 *hwmp_ie) 255 { 256 struct ieee80211_local *local = sdata->local; 257 struct mesh_path *mpath; 258 struct sta_info *sta; 259 bool fresh_info; 260 u8 *orig_addr, *ta; 261 u32 orig_dsn, orig_metric; 262 unsigned long orig_lifetime, exp_time; 263 u32 last_hop_metric, new_metric; 264 bool process = true; 265 u8 action = mgmt->u.action.u.mesh_action.action_code; 266 267 rcu_read_lock(); 268 sta = sta_info_get(local, mgmt->sa); 269 if (!sta) { 270 rcu_read_unlock(); 271 return 0; 272 } 273 274 last_hop_metric = airtime_link_metric_get(local, sta); 275 /* Update and check originator routing info */ 276 fresh_info = true; 277 278 switch (action) { 279 case MPATH_PREQ: 280 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); 281 orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie); 282 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); 283 orig_metric = PREQ_IE_METRIC(hwmp_ie); 284 break; 285 case MPATH_PREP: 286 /* Originator here refers to the MP that was the destination in 287 * the Path Request. The draft refers to that MP as the 288 * destination address, even though usually it is the origin of 289 * the PREP frame. We divert from the nomenclature in the draft 290 * so that we can easily use a single function to gather path 291 * information from both PREQ and PREP frames. 292 */ 293 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie); 294 orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie); 295 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); 296 orig_metric = PREP_IE_METRIC(hwmp_ie); 297 break; 298 default: 299 rcu_read_unlock(); 300 return 0; 301 } 302 new_metric = orig_metric + last_hop_metric; 303 if (new_metric < orig_metric) 304 new_metric = MAX_METRIC; 305 exp_time = TU_TO_EXP_TIME(orig_lifetime); 306 307 if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 308 /* This MP is the originator, we are not interested in this 309 * frame, except for updating transmitter's path info. 310 */ 311 process = false; 312 fresh_info = false; 313 } else { 314 mpath = mesh_path_lookup(orig_addr, sdata); 315 if (mpath) { 316 spin_lock_bh(&mpath->state_lock); 317 if (mpath->flags & MESH_PATH_FIXED) 318 fresh_info = false; 319 else if ((mpath->flags & MESH_PATH_ACTIVE) && 320 (mpath->flags & MESH_PATH_DSN_VALID)) { 321 if (DSN_GT(mpath->dsn, orig_dsn) || 322 (mpath->dsn == orig_dsn && 323 action == MPATH_PREQ && 324 new_metric > mpath->metric)) { 325 process = false; 326 fresh_info = false; 327 } 328 } 329 } else { 330 mesh_path_add(orig_addr, sdata); 331 mpath = mesh_path_lookup(orig_addr, sdata); 332 if (!mpath) { 333 rcu_read_unlock(); 334 return 0; 335 } 336 spin_lock_bh(&mpath->state_lock); 337 } 338 339 if (fresh_info) { 340 mesh_path_assign_nexthop(mpath, sta); 341 mpath->flags |= MESH_PATH_DSN_VALID; 342 mpath->metric = new_metric; 343 mpath->dsn = orig_dsn; 344 mpath->exp_time = time_after(mpath->exp_time, exp_time) 345 ? mpath->exp_time : exp_time; 346 mesh_path_activate(mpath); 347 spin_unlock_bh(&mpath->state_lock); 348 mesh_path_tx_pending(mpath); 349 /* draft says preq_id should be saved to, but there does 350 * not seem to be any use for it, skipping by now 351 */ 352 } else 353 spin_unlock_bh(&mpath->state_lock); 354 } 355 356 /* Update and check transmitter routing info */ 357 ta = mgmt->sa; 358 if (memcmp(orig_addr, ta, ETH_ALEN) == 0) 359 fresh_info = false; 360 else { 361 fresh_info = true; 362 363 mpath = mesh_path_lookup(ta, sdata); 364 if (mpath) { 365 spin_lock_bh(&mpath->state_lock); 366 if ((mpath->flags & MESH_PATH_FIXED) || 367 ((mpath->flags & MESH_PATH_ACTIVE) && 368 (last_hop_metric > mpath->metric))) 369 fresh_info = false; 370 } else { 371 mesh_path_add(ta, sdata); 372 mpath = mesh_path_lookup(ta, sdata); 373 if (!mpath) { 374 rcu_read_unlock(); 375 return 0; 376 } 377 spin_lock_bh(&mpath->state_lock); 378 } 379 380 if (fresh_info) { 381 mesh_path_assign_nexthop(mpath, sta); 382 mpath->flags &= ~MESH_PATH_DSN_VALID; 383 mpath->metric = last_hop_metric; 384 mpath->exp_time = time_after(mpath->exp_time, exp_time) 385 ? mpath->exp_time : exp_time; 386 mesh_path_activate(mpath); 387 spin_unlock_bh(&mpath->state_lock); 388 mesh_path_tx_pending(mpath); 389 } else 390 spin_unlock_bh(&mpath->state_lock); 391 } 392 393 rcu_read_unlock(); 394 395 return process ? new_metric : 0; 396 } 397 398 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, 399 struct ieee80211_mgmt *mgmt, 400 u8 *preq_elem, u32 metric) { 401 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 402 struct mesh_path *mpath; 403 u8 *dst_addr, *orig_addr; 404 u8 dst_flags, ttl; 405 u32 orig_dsn, dst_dsn, lifetime; 406 bool reply = false; 407 bool forward = true; 408 409 /* Update destination DSN, if present */ 410 dst_addr = PREQ_IE_DST_ADDR(preq_elem); 411 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); 412 dst_dsn = PREQ_IE_DST_DSN(preq_elem); 413 orig_dsn = PREQ_IE_ORIG_DSN(preq_elem); 414 dst_flags = PREQ_IE_DST_F(preq_elem); 415 416 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) { 417 forward = false; 418 reply = true; 419 metric = 0; 420 if (time_after(jiffies, ifmsh->last_dsn_update + 421 net_traversal_jiffies(sdata)) || 422 time_before(jiffies, ifmsh->last_dsn_update)) { 423 dst_dsn = ++ifmsh->dsn; 424 ifmsh->last_dsn_update = jiffies; 425 } 426 } else { 427 rcu_read_lock(); 428 mpath = mesh_path_lookup(dst_addr, sdata); 429 if (mpath) { 430 if ((!(mpath->flags & MESH_PATH_DSN_VALID)) || 431 DSN_LT(mpath->dsn, dst_dsn)) { 432 mpath->dsn = dst_dsn; 433 mpath->flags &= MESH_PATH_DSN_VALID; 434 } else if ((!(dst_flags & MP_F_DO)) && 435 (mpath->flags & MESH_PATH_ACTIVE)) { 436 reply = true; 437 metric = mpath->metric; 438 dst_dsn = mpath->dsn; 439 if (dst_flags & MP_F_RF) 440 dst_flags |= MP_F_DO; 441 else 442 forward = false; 443 } 444 } 445 rcu_read_unlock(); 446 } 447 448 if (reply) { 449 lifetime = PREQ_IE_LIFETIME(preq_elem); 450 ttl = ifmsh->mshcfg.dot11MeshTTL; 451 if (ttl != 0) 452 mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr, 453 cpu_to_le32(dst_dsn), 0, orig_addr, 454 cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl, 455 cpu_to_le32(lifetime), cpu_to_le32(metric), 456 0, sdata); 457 else 458 ifmsh->mshstats.dropped_frames_ttl++; 459 } 460 461 if (forward) { 462 u32 preq_id; 463 u8 hopcount, flags; 464 465 ttl = PREQ_IE_TTL(preq_elem); 466 lifetime = PREQ_IE_LIFETIME(preq_elem); 467 if (ttl <= 1) { 468 ifmsh->mshstats.dropped_frames_ttl++; 469 return; 470 } 471 --ttl; 472 flags = PREQ_IE_FLAGS(preq_elem); 473 preq_id = PREQ_IE_PREQ_ID(preq_elem); 474 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; 475 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, 476 cpu_to_le32(orig_dsn), dst_flags, dst_addr, 477 cpu_to_le32(dst_dsn), sdata->dev->broadcast, 478 hopcount, ttl, cpu_to_le32(lifetime), 479 cpu_to_le32(metric), cpu_to_le32(preq_id), 480 sdata); 481 ifmsh->mshstats.fwded_frames++; 482 } 483 } 484 485 486 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, 487 struct ieee80211_mgmt *mgmt, 488 u8 *prep_elem, u32 metric) 489 { 490 struct mesh_path *mpath; 491 u8 *dst_addr, *orig_addr; 492 u8 ttl, hopcount, flags; 493 u8 next_hop[ETH_ALEN]; 494 u32 dst_dsn, orig_dsn, lifetime; 495 496 /* Note that we divert from the draft nomenclature and denominate 497 * destination to what the draft refers to as origininator. So in this 498 * function destnation refers to the final destination of the PREP, 499 * which corresponds with the originator of the PREQ which this PREP 500 * replies 501 */ 502 dst_addr = PREP_IE_DST_ADDR(prep_elem); 503 if (memcmp(dst_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) 504 /* destination, no forwarding required */ 505 return; 506 507 ttl = PREP_IE_TTL(prep_elem); 508 if (ttl <= 1) { 509 sdata->u.mesh.mshstats.dropped_frames_ttl++; 510 return; 511 } 512 513 rcu_read_lock(); 514 mpath = mesh_path_lookup(dst_addr, sdata); 515 if (mpath) 516 spin_lock_bh(&mpath->state_lock); 517 else 518 goto fail; 519 if (!(mpath->flags & MESH_PATH_ACTIVE)) { 520 spin_unlock_bh(&mpath->state_lock); 521 goto fail; 522 } 523 memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN); 524 spin_unlock_bh(&mpath->state_lock); 525 --ttl; 526 flags = PREP_IE_FLAGS(prep_elem); 527 lifetime = PREP_IE_LIFETIME(prep_elem); 528 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; 529 orig_addr = PREP_IE_ORIG_ADDR(prep_elem); 530 dst_dsn = PREP_IE_DST_DSN(prep_elem); 531 orig_dsn = PREP_IE_ORIG_DSN(prep_elem); 532 533 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, 534 cpu_to_le32(orig_dsn), 0, dst_addr, 535 cpu_to_le32(dst_dsn), mpath->next_hop->sta.addr, hopcount, ttl, 536 cpu_to_le32(lifetime), cpu_to_le32(metric), 537 0, sdata); 538 rcu_read_unlock(); 539 sdata->u.mesh.mshstats.fwded_frames++; 540 return; 541 542 fail: 543 rcu_read_unlock(); 544 sdata->u.mesh.mshstats.dropped_frames_no_route++; 545 return; 546 } 547 548 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, 549 struct ieee80211_mgmt *mgmt, u8 *perr_elem) 550 { 551 struct mesh_path *mpath; 552 u8 *ta, *dst_addr; 553 u32 dst_dsn; 554 555 ta = mgmt->sa; 556 dst_addr = PERR_IE_DST_ADDR(perr_elem); 557 dst_dsn = PERR_IE_DST_DSN(perr_elem); 558 rcu_read_lock(); 559 mpath = mesh_path_lookup(dst_addr, sdata); 560 if (mpath) { 561 spin_lock_bh(&mpath->state_lock); 562 if (mpath->flags & MESH_PATH_ACTIVE && 563 memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 && 564 (!(mpath->flags & MESH_PATH_DSN_VALID) || 565 DSN_GT(dst_dsn, mpath->dsn))) { 566 mpath->flags &= ~MESH_PATH_ACTIVE; 567 mpath->dsn = dst_dsn; 568 spin_unlock_bh(&mpath->state_lock); 569 mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn), 570 sdata->dev->broadcast, sdata); 571 } else 572 spin_unlock_bh(&mpath->state_lock); 573 } 574 rcu_read_unlock(); 575 } 576 577 578 579 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 580 struct ieee80211_mgmt *mgmt, 581 size_t len) 582 { 583 struct ieee802_11_elems elems; 584 size_t baselen; 585 u32 last_hop_metric; 586 587 /* need action_code */ 588 if (len < IEEE80211_MIN_ACTION_SIZE + 1) 589 return; 590 591 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; 592 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, 593 len - baselen, &elems); 594 595 switch (mgmt->u.action.u.mesh_action.action_code) { 596 case MPATH_PREQ: 597 if (!elems.preq || elems.preq_len != 37) 598 /* Right now we support just 1 destination and no AE */ 599 return; 600 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq); 601 if (!last_hop_metric) 602 return; 603 hwmp_preq_frame_process(sdata, mgmt, elems.preq, last_hop_metric); 604 break; 605 case MPATH_PREP: 606 if (!elems.prep || elems.prep_len != 31) 607 /* Right now we support no AE */ 608 return; 609 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep); 610 if (!last_hop_metric) 611 return; 612 hwmp_prep_frame_process(sdata, mgmt, elems.prep, last_hop_metric); 613 break; 614 case MPATH_PERR: 615 if (!elems.perr || elems.perr_len != 12) 616 /* Right now we support only one destination per PERR */ 617 return; 618 hwmp_perr_frame_process(sdata, mgmt, elems.perr); 619 default: 620 return; 621 } 622 623 } 624 625 /** 626 * mesh_queue_preq - queue a PREQ to a given destination 627 * 628 * @mpath: mesh path to discover 629 * @flags: special attributes of the PREQ to be sent 630 * 631 * Locking: the function must be called from within a rcu read lock block. 632 * 633 */ 634 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) 635 { 636 struct ieee80211_sub_if_data *sdata = mpath->sdata; 637 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 638 struct mesh_preq_queue *preq_node; 639 640 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_KERNEL); 641 if (!preq_node) { 642 printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n"); 643 return; 644 } 645 646 spin_lock(&ifmsh->mesh_preq_queue_lock); 647 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { 648 spin_unlock(&ifmsh->mesh_preq_queue_lock); 649 kfree(preq_node); 650 if (printk_ratelimit()) 651 printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n"); 652 return; 653 } 654 655 memcpy(preq_node->dst, mpath->dst, ETH_ALEN); 656 preq_node->flags = flags; 657 658 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); 659 ++ifmsh->preq_queue_len; 660 spin_unlock(&ifmsh->mesh_preq_queue_lock); 661 662 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) 663 queue_work(sdata->local->hw.workqueue, &ifmsh->work); 664 665 else if (time_before(jiffies, ifmsh->last_preq)) { 666 /* avoid long wait if did not send preqs for a long time 667 * and jiffies wrapped around 668 */ 669 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; 670 queue_work(sdata->local->hw.workqueue, &ifmsh->work); 671 } else 672 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + 673 min_preq_int_jiff(sdata)); 674 } 675 676 /** 677 * mesh_path_start_discovery - launch a path discovery from the PREQ queue 678 * 679 * @sdata: local mesh subif 680 */ 681 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) 682 { 683 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; 684 struct mesh_preq_queue *preq_node; 685 struct mesh_path *mpath; 686 u8 ttl, dst_flags; 687 u32 lifetime; 688 689 spin_lock(&ifmsh->mesh_preq_queue_lock); 690 if (!ifmsh->preq_queue_len || 691 time_before(jiffies, ifmsh->last_preq + 692 min_preq_int_jiff(sdata))) { 693 spin_unlock(&ifmsh->mesh_preq_queue_lock); 694 return; 695 } 696 697 preq_node = list_first_entry(&ifmsh->preq_queue.list, 698 struct mesh_preq_queue, list); 699 list_del(&preq_node->list); 700 --ifmsh->preq_queue_len; 701 spin_unlock(&ifmsh->mesh_preq_queue_lock); 702 703 rcu_read_lock(); 704 mpath = mesh_path_lookup(preq_node->dst, sdata); 705 if (!mpath) 706 goto enddiscovery; 707 708 spin_lock_bh(&mpath->state_lock); 709 if (preq_node->flags & PREQ_Q_F_START) { 710 if (mpath->flags & MESH_PATH_RESOLVING) { 711 spin_unlock_bh(&mpath->state_lock); 712 goto enddiscovery; 713 } else { 714 mpath->flags &= ~MESH_PATH_RESOLVED; 715 mpath->flags |= MESH_PATH_RESOLVING; 716 mpath->discovery_retries = 0; 717 mpath->discovery_timeout = disc_timeout_jiff(sdata); 718 } 719 } else if (!(mpath->flags & MESH_PATH_RESOLVING) || 720 mpath->flags & MESH_PATH_RESOLVED) { 721 mpath->flags &= ~MESH_PATH_RESOLVING; 722 spin_unlock_bh(&mpath->state_lock); 723 goto enddiscovery; 724 } 725 726 ifmsh->last_preq = jiffies; 727 728 if (time_after(jiffies, ifmsh->last_dsn_update + 729 net_traversal_jiffies(sdata)) || 730 time_before(jiffies, ifmsh->last_dsn_update)) { 731 ++ifmsh->dsn; 732 sdata->u.mesh.last_dsn_update = jiffies; 733 } 734 lifetime = default_lifetime(sdata); 735 ttl = sdata->u.mesh.mshcfg.dot11MeshTTL; 736 if (ttl == 0) { 737 sdata->u.mesh.mshstats.dropped_frames_ttl++; 738 spin_unlock_bh(&mpath->state_lock); 739 goto enddiscovery; 740 } 741 742 if (preq_node->flags & PREQ_Q_F_REFRESH) 743 dst_flags = MP_F_DO; 744 else 745 dst_flags = MP_F_RF; 746 747 spin_unlock_bh(&mpath->state_lock); 748 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->dev->dev_addr, 749 cpu_to_le32(ifmsh->dsn), dst_flags, mpath->dst, 750 cpu_to_le32(mpath->dsn), sdata->dev->broadcast, 0, 751 ttl, cpu_to_le32(lifetime), 0, 752 cpu_to_le32(ifmsh->preq_id++), sdata); 753 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); 754 755 enddiscovery: 756 rcu_read_unlock(); 757 kfree(preq_node); 758 } 759 760 /** 761 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame 762 * 763 * @skb: 802.11 frame to be sent 764 * @sdata: network subif the frame will be sent through 765 * 766 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is 767 * found, the function will start a path discovery and queue the frame so it is 768 * sent when the path is resolved. This means the caller must not free the skb 769 * in this case. 770 */ 771 int mesh_nexthop_lookup(struct sk_buff *skb, 772 struct ieee80211_sub_if_data *sdata) 773 { 774 struct sk_buff *skb_to_free = NULL; 775 struct mesh_path *mpath; 776 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 777 u8 *dst_addr = hdr->addr3; 778 int err = 0; 779 780 rcu_read_lock(); 781 mpath = mesh_path_lookup(dst_addr, sdata); 782 783 if (!mpath) { 784 mesh_path_add(dst_addr, sdata); 785 mpath = mesh_path_lookup(dst_addr, sdata); 786 if (!mpath) { 787 dev_kfree_skb(skb); 788 sdata->u.mesh.mshstats.dropped_frames_no_route++; 789 err = -ENOSPC; 790 goto endlookup; 791 } 792 } 793 794 if (mpath->flags & MESH_PATH_ACTIVE) { 795 if (time_after(jiffies, mpath->exp_time - 796 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) 797 && !memcmp(sdata->dev->dev_addr, hdr->addr4, 798 ETH_ALEN) 799 && !(mpath->flags & MESH_PATH_RESOLVING) 800 && !(mpath->flags & MESH_PATH_FIXED)) { 801 mesh_queue_preq(mpath, 802 PREQ_Q_F_START | PREQ_Q_F_REFRESH); 803 } 804 memcpy(hdr->addr1, mpath->next_hop->sta.addr, 805 ETH_ALEN); 806 } else { 807 if (!(mpath->flags & MESH_PATH_RESOLVING)) { 808 /* Start discovery only if it is not running yet */ 809 mesh_queue_preq(mpath, PREQ_Q_F_START); 810 } 811 812 if (skb_queue_len(&mpath->frame_queue) >= 813 MESH_FRAME_QUEUE_LEN) { 814 skb_to_free = mpath->frame_queue.next; 815 skb_unlink(skb_to_free, &mpath->frame_queue); 816 } 817 818 skb_queue_tail(&mpath->frame_queue, skb); 819 if (skb_to_free) 820 mesh_path_discard_frame(skb_to_free, sdata); 821 err = -ENOENT; 822 } 823 824 endlookup: 825 rcu_read_unlock(); 826 return err; 827 } 828 829 void mesh_path_timer(unsigned long data) 830 { 831 struct ieee80211_sub_if_data *sdata; 832 struct mesh_path *mpath; 833 834 rcu_read_lock(); 835 mpath = (struct mesh_path *) data; 836 mpath = rcu_dereference(mpath); 837 if (!mpath) 838 goto endmpathtimer; 839 spin_lock_bh(&mpath->state_lock); 840 sdata = mpath->sdata; 841 if (mpath->flags & MESH_PATH_RESOLVED || 842 (!(mpath->flags & MESH_PATH_RESOLVING))) 843 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); 844 else if (mpath->discovery_retries < max_preq_retries(sdata)) { 845 ++mpath->discovery_retries; 846 mpath->discovery_timeout *= 2; 847 mesh_queue_preq(mpath, 0); 848 } else { 849 mpath->flags = 0; 850 mpath->exp_time = jiffies; 851 mesh_path_flush_pending(mpath); 852 } 853 854 spin_unlock_bh(&mpath->state_lock); 855 endmpathtimer: 856 rcu_read_unlock(); 857 } 858