?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'akpm'
[linux-2.6/next.git] / net / mac80211 / mesh_hwmp.c
blobfd4f76a3e139ef3fb88211e058a58b044792a369
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...) \
15 printk(KERN_DEBUG "Mesh HWMP (%s): " fmt "\n", sdata->name, ##args)
16 #else
17 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0)
18 #endif
19
20 #define TEST_FRAME_LEN 8192
21 #define MAX_METRIC 0xffffffff
22 #define ARITH_SHIFT 8
23
24 /* Number of frames buffered per destination for unresolved destinations */
25 #define MESH_FRAME_QUEUE_LEN 10
26 #define MAX_PREQ_QUEUE_LEN 64
27
28 /* Destination only */
29 #define MP_F_DO 0x1
30 /* Reply and forward */
31 #define MP_F_RF 0x2
32 /* Unknown Sequence Number */
33 #define MP_F_USN 0x01
34 /* Reason code Present */
35 #define MP_F_RCODE 0x02
36
37 static void mesh_queue_preq(struct mesh_path *, u8);
38
39 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
40 {
41 if (ae)
42 offset += 6;
43 return get_unaligned_le32(preq_elem + offset);
44 }
45
46 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
47 {
48 if (ae)
49 offset += 6;
50 return get_unaligned_le16(preq_elem + offset);
51 }
52
53 /* HWMP IE processing macros */
54 #define AE_F (1<<6)
55 #define AE_F_SET(x) (*x & AE_F)
56 #define PREQ_IE_FLAGS(x) (*(x))
57 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
58 #define PREQ_IE_TTL(x) (*(x + 2))
59 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
60 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
61 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
62 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
63 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
64 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
65 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
66 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
67
68
69 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
70 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
71 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
72 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
73 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
74 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
75 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
76 #define PREP_IE_TARGET_ADDR(x) (x + 3)
77 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
78
79 #define PERR_IE_TTL(x) (*(x))
80 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
81 #define PERR_IE_TARGET_ADDR(x) (x + 3)
82 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
83 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
84
85 #define MSEC_TO_TU(x) (x*1000/1024)
86 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0)
87 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0)
88
89 #define net_traversal_jiffies(s) \
90 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
91 #define default_lifetime(s) \
92 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
93 #define min_preq_int_jiff(s) \
94 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
95 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
96 #define disc_timeout_jiff(s) \
97 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
98
99 enum mpath_frame_type {
100 MPATH_PREQ = 0,
101 MPATH_PREP,
102 MPATH_PERR,
103 MPATH_RANN
104 };
105
106 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
107
108 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
109 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target,
110 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl,
111 __le32 lifetime, __le32 metric, __le32 preq_id,
112 struct ieee80211_sub_if_data *sdata)
113 {
114 struct ieee80211_local *local = sdata->local;
115 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
116 struct ieee80211_mgmt *mgmt;
117 u8 *pos;
118 int ie_len;
119
120 if (!skb)
121 return -1;
122 skb_reserve(skb, local->hw.extra_tx_headroom);
123 /* 25 is the size of the common mgmt part (24) plus the size of the
124 * common action part (1)
125 */
126 mgmt = (struct ieee80211_mgmt *)
127 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
128 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
129 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
130 IEEE80211_STYPE_ACTION);
131
132 memcpy(mgmt->da, da, ETH_ALEN);
133 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
134 /* BSSID == SA */
135 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
136 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
137 mgmt->u.action.u.mesh_action.action_code =
138 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
139
140 switch (action) {
141 case MPATH_PREQ:
142 mhwmp_dbg("sending PREQ to %pM", target);
143 ie_len = 37;
144 pos = skb_put(skb, 2 + ie_len);
145 *pos++ = WLAN_EID_PREQ;
146 break;
147 case MPATH_PREP:
148 mhwmp_dbg("sending PREP to %pM", target);
149 ie_len = 31;
150 pos = skb_put(skb, 2 + ie_len);
151 *pos++ = WLAN_EID_PREP;
152 break;
153 case MPATH_RANN:
154 mhwmp_dbg("sending RANN from %pM", orig_addr);
155 ie_len = sizeof(struct ieee80211_rann_ie);
156 pos = skb_put(skb, 2 + ie_len);
157 *pos++ = WLAN_EID_RANN;
158 break;
159 default:
160 kfree_skb(skb);
161 return -ENOTSUPP;
162 break;
163 }
164 *pos++ = ie_len;
165 *pos++ = flags;
166 *pos++ = hop_count;
167 *pos++ = ttl;
168 if (action == MPATH_PREP) {
169 memcpy(pos, target, ETH_ALEN);
170 pos += ETH_ALEN;
171 memcpy(pos, &target_sn, 4);
172 pos += 4;
173 } else {
174 if (action == MPATH_PREQ) {
175 memcpy(pos, &preq_id, 4);
176 pos += 4;
177 }
178 memcpy(pos, orig_addr, ETH_ALEN);
179 pos += ETH_ALEN;
180 memcpy(pos, &orig_sn, 4);
181 pos += 4;
182 }
183 memcpy(pos, &lifetime, 4); /* interval for RANN */
184 pos += 4;
185 memcpy(pos, &metric, 4);
186 pos += 4;
187 if (action == MPATH_PREQ) {
188 *pos++ = 1; /* destination count */
189 *pos++ = target_flags;
190 memcpy(pos, target, ETH_ALEN);
191 pos += ETH_ALEN;
192 memcpy(pos, &target_sn, 4);
193 pos += 4;
194 } else if (action == MPATH_PREP) {
195 memcpy(pos, orig_addr, ETH_ALEN);
196 pos += ETH_ALEN;
197 memcpy(pos, &orig_sn, 4);
198 pos += 4;
199 }
200
201 ieee80211_tx_skb(sdata, skb);
202 return 0;
203 }
204
205 /**
206 * mesh_send_path error - Sends a PERR mesh management frame
207 *
208 * @target: broken destination
209 * @target_sn: SN of the broken destination
210 * @target_rcode: reason code for this PERR
211 * @ra: node this frame is addressed to
212 */
213 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
214 __le16 target_rcode, const u8 *ra,
215 struct ieee80211_sub_if_data *sdata)
216 {
217 struct ieee80211_local *local = sdata->local;
218 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
219 struct ieee80211_mgmt *mgmt;
220 u8 *pos;
221 int ie_len;
222
223 if (!skb)
224 return -1;
225 skb_reserve(skb, local->hw.extra_tx_headroom);
226 /* 25 is the size of the common mgmt part (24) plus the size of the
227 * common action part (1)
228 */
229 mgmt = (struct ieee80211_mgmt *)
230 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
231 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
232 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
233 IEEE80211_STYPE_ACTION);
234
235 memcpy(mgmt->da, ra, ETH_ALEN);
236 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
237 /* BSSID == SA */
238 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
239 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
240 mgmt->u.action.u.mesh_action.action_code =
241 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
242 ie_len = 15;
243 pos = skb_put(skb, 2 + ie_len);
244 *pos++ = WLAN_EID_PERR;
245 *pos++ = ie_len;
246 /* ttl */
247 *pos++ = ttl;
248 /* number of destinations */
249 *pos++ = 1;
250 /*
251 * flags bit, bit 1 is unset if we know the sequence number and
252 * bit 2 is set if we have a reason code
253 */
254 *pos = 0;
255 if (!target_sn)
256 *pos |= MP_F_USN;
257 if (target_rcode)
258 *pos |= MP_F_RCODE;
259 pos++;
260 memcpy(pos, target, ETH_ALEN);
261 pos += ETH_ALEN;
262 memcpy(pos, &target_sn, 4);
263 pos += 4;
264 memcpy(pos, &target_rcode, 2);
265
266 ieee80211_tx_skb(sdata, skb);
267 return 0;
268 }
269
270 void ieee80211s_update_metric(struct ieee80211_local *local,
271 struct sta_info *stainfo, struct sk_buff *skb)
272 {
273 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
274 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
275 int failed;
276
277 if (!ieee80211_is_data(hdr->frame_control))
278 return;
279
280 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
281
282 /* moving average, scaled to 100 */
283 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
284 if (stainfo->fail_avg > 95)
285 mesh_plink_broken(stainfo);
286 }
287
288 static u32 airtime_link_metric_get(struct ieee80211_local *local,
289 struct sta_info *sta)
290 {
291 struct ieee80211_supported_band *sband;
292 /* This should be adjusted for each device */
293 int device_constant = 1 << ARITH_SHIFT;
294 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
295 int s_unit = 1 << ARITH_SHIFT;
296 int rate, err;
297 u32 tx_time, estimated_retx;
298 u64 result;
299
300 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
301
302 if (sta->fail_avg >= 100)
303 return MAX_METRIC;
304
305 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
306 return MAX_METRIC;
307
308 err = (sta->fail_avg << ARITH_SHIFT) / 100;
309
310 /* bitrate is in units of 100 Kbps, while we need rate in units of
311 * 1Mbps. This will be corrected on tx_time computation.
312 */
313 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
314 tx_time = (device_constant + 10 * test_frame_len / rate);
315 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
316 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
317 return (u32)result;
318 }
319
320 /**
321 * hwmp_route_info_get - Update routing info to originator and transmitter
322 *
323 * @sdata: local mesh subif
324 * @mgmt: mesh management frame
325 * @hwmp_ie: hwmp information element (PREP or PREQ)
326 *
327 * This function updates the path routing information to the originator and the
328 * transmitter of a HWMP PREQ or PREP frame.
329 *
330 * Returns: metric to frame originator or 0 if the frame should not be further
331 * processed
332 *
333 * Notes: this function is the only place (besides user-provided info) where
334 * path routing information is updated.
335 */
336 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
337 struct ieee80211_mgmt *mgmt,
338 u8 *hwmp_ie, enum mpath_frame_type action)
339 {
340 struct ieee80211_local *local = sdata->local;
341 struct mesh_path *mpath;
342 struct sta_info *sta;
343 bool fresh_info;
344 u8 *orig_addr, *ta;
345 u32 orig_sn, orig_metric;
346 unsigned long orig_lifetime, exp_time;
347 u32 last_hop_metric, new_metric;
348 bool process = true;
349
350 rcu_read_lock();
351 sta = sta_info_get(sdata, mgmt->sa);
352 if (!sta) {
353 rcu_read_unlock();
354 return 0;
355 }
356
357 last_hop_metric = airtime_link_metric_get(local, sta);
358 /* Update and check originator routing info */
359 fresh_info = true;
360
361 switch (action) {
362 case MPATH_PREQ:
363 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
364 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
365 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
366 orig_metric = PREQ_IE_METRIC(hwmp_ie);
367 break;
368 case MPATH_PREP:
369 /* Originator here refers to the MP that was the destination in
370 * the Path Request. The draft refers to that MP as the
371 * destination address, even though usually it is the origin of
372 * the PREP frame. We divert from the nomenclature in the draft
373 * so that we can easily use a single function to gather path
374 * information from both PREQ and PREP frames.
375 */
376 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
377 orig_sn = PREP_IE_ORIG_SN(hwmp_ie);
378 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
379 orig_metric = PREP_IE_METRIC(hwmp_ie);
380 break;
381 default:
382 rcu_read_unlock();
383 return 0;
384 }
385 new_metric = orig_metric + last_hop_metric;
386 if (new_metric < orig_metric)
387 new_metric = MAX_METRIC;
388 exp_time = TU_TO_EXP_TIME(orig_lifetime);
389
390 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) {
391 /* This MP is the originator, we are not interested in this
392 * frame, except for updating transmitter's path info.
393 */
394 process = false;
395 fresh_info = false;
396 } else {
397 mpath = mesh_path_lookup(orig_addr, sdata);
398 if (mpath) {
399 spin_lock_bh(&mpath->state_lock);
400 if (mpath->flags & MESH_PATH_FIXED)
401 fresh_info = false;
402 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
403 (mpath->flags & MESH_PATH_SN_VALID)) {
404 if (SN_GT(mpath->sn, orig_sn) ||
405 (mpath->sn == orig_sn &&
406 new_metric >= mpath->metric)) {
407 process = false;
408 fresh_info = false;
409 }
410 }
411 } else {
412 mesh_path_add(orig_addr, sdata);
413 mpath = mesh_path_lookup(orig_addr, sdata);
414 if (!mpath) {
415 rcu_read_unlock();
416 return 0;
417 }
418 spin_lock_bh(&mpath->state_lock);
419 }
420
421 if (fresh_info) {
422 mesh_path_assign_nexthop(mpath, sta);
423 mpath->flags |= MESH_PATH_SN_VALID;
424 mpath->metric = new_metric;
425 mpath->sn = orig_sn;
426 mpath->exp_time = time_after(mpath->exp_time, exp_time)
427 ? mpath->exp_time : exp_time;
428 mesh_path_activate(mpath);
429 spin_unlock_bh(&mpath->state_lock);
430 mesh_path_tx_pending(mpath);
431 /* draft says preq_id should be saved to, but there does
432 * not seem to be any use for it, skipping by now
433 */
434 } else
435 spin_unlock_bh(&mpath->state_lock);
436 }
437
438 /* Update and check transmitter routing info */
439 ta = mgmt->sa;
440 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
441 fresh_info = false;
442 else {
443 fresh_info = true;
444
445 mpath = mesh_path_lookup(ta, sdata);
446 if (mpath) {
447 spin_lock_bh(&mpath->state_lock);
448 if ((mpath->flags & MESH_PATH_FIXED) ||
449 ((mpath->flags & MESH_PATH_ACTIVE) &&
450 (last_hop_metric > mpath->metric)))
451 fresh_info = false;
452 } else {
453 mesh_path_add(ta, sdata);
454 mpath = mesh_path_lookup(ta, sdata);
455 if (!mpath) {
456 rcu_read_unlock();
457 return 0;
458 }
459 spin_lock_bh(&mpath->state_lock);
460 }
461
462 if (fresh_info) {
463 mesh_path_assign_nexthop(mpath, sta);
464 mpath->metric = last_hop_metric;
465 mpath->exp_time = time_after(mpath->exp_time, exp_time)
466 ? mpath->exp_time : exp_time;
467 mesh_path_activate(mpath);
468 spin_unlock_bh(&mpath->state_lock);
469 mesh_path_tx_pending(mpath);
470 } else
471 spin_unlock_bh(&mpath->state_lock);
472 }
473
474 rcu_read_unlock();
475
476 return process ? new_metric : 0;
477 }
478
479 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
480 struct ieee80211_mgmt *mgmt,
481 u8 *preq_elem, u32 metric)
482 {
483 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
484 struct mesh_path *mpath;
485 u8 *target_addr, *orig_addr;
486 u8 target_flags, ttl;
487 u32 orig_sn, target_sn, lifetime;
488 bool reply = false;
489 bool forward = true;
490
491 /* Update target SN, if present */
492 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
493 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
494 target_sn = PREQ_IE_TARGET_SN(preq_elem);
495 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
496 target_flags = PREQ_IE_TARGET_F(preq_elem);
497
498 mhwmp_dbg("received PREQ from %pM", orig_addr);
499
500 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) {
501 mhwmp_dbg("PREQ is for us");
502 forward = false;
503 reply = true;
504 metric = 0;
505 if (time_after(jiffies, ifmsh->last_sn_update +
506 net_traversal_jiffies(sdata)) ||
507 time_before(jiffies, ifmsh->last_sn_update)) {
508 target_sn = ++ifmsh->sn;
509 ifmsh->last_sn_update = jiffies;
510 }
511 } else {
512 rcu_read_lock();
513 mpath = mesh_path_lookup(target_addr, sdata);
514 if (mpath) {
515 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
516 SN_LT(mpath->sn, target_sn)) {
517 mpath->sn = target_sn;
518 mpath->flags |= MESH_PATH_SN_VALID;
519 } else if ((!(target_flags & MP_F_DO)) &&
520 (mpath->flags & MESH_PATH_ACTIVE)) {
521 reply = true;
522 metric = mpath->metric;
523 target_sn = mpath->sn;
524 if (target_flags & MP_F_RF)
525 target_flags |= MP_F_DO;
526 else
527 forward = false;
528 }
529 }
530 rcu_read_unlock();
531 }
532
533 if (reply) {
534 lifetime = PREQ_IE_LIFETIME(preq_elem);
535 ttl = ifmsh->mshcfg.element_ttl;
536 if (ttl != 0) {
537 mhwmp_dbg("replying to the PREQ");
538 mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr,
539 cpu_to_le32(target_sn), 0, orig_addr,
540 cpu_to_le32(orig_sn), mgmt->sa, 0, ttl,
541 cpu_to_le32(lifetime), cpu_to_le32(metric),
542 0, sdata);
543 } else
544 ifmsh->mshstats.dropped_frames_ttl++;
545 }
546
547 if (forward) {
548 u32 preq_id;
549 u8 hopcount, flags;
550
551 ttl = PREQ_IE_TTL(preq_elem);
552 lifetime = PREQ_IE_LIFETIME(preq_elem);
553 if (ttl <= 1) {
554 ifmsh->mshstats.dropped_frames_ttl++;
555 return;
556 }
557 mhwmp_dbg("forwarding the PREQ from %pM", orig_addr);
558 --ttl;
559 flags = PREQ_IE_FLAGS(preq_elem);
560 preq_id = PREQ_IE_PREQ_ID(preq_elem);
561 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
562 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
563 cpu_to_le32(orig_sn), target_flags, target_addr,
564 cpu_to_le32(target_sn), broadcast_addr,
565 hopcount, ttl, cpu_to_le32(lifetime),
566 cpu_to_le32(metric), cpu_to_le32(preq_id),
567 sdata);
568 ifmsh->mshstats.fwded_mcast++;
569 ifmsh->mshstats.fwded_frames++;
570 }
571 }
572
573
574 static inline struct sta_info *
575 next_hop_deref_protected(struct mesh_path *mpath)
576 {
577 return rcu_dereference_protected(mpath->next_hop,
578 lockdep_is_held(&mpath->state_lock));
579 }
580
581
582 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
583 struct ieee80211_mgmt *mgmt,
584 u8 *prep_elem, u32 metric)
585 {
586 struct mesh_path *mpath;
587 u8 *target_addr, *orig_addr;
588 u8 ttl, hopcount, flags;
589 u8 next_hop[ETH_ALEN];
590 u32 target_sn, orig_sn, lifetime;
591
592 mhwmp_dbg("received PREP from %pM", PREP_IE_ORIG_ADDR(prep_elem));
593
594 /* Note that we divert from the draft nomenclature and denominate
595 * destination to what the draft refers to as origininator. So in this
596 * function destnation refers to the final destination of the PREP,
597 * which corresponds with the originator of the PREQ which this PREP
598 * replies
599 */
600 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
601 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0)
602 /* destination, no forwarding required */
603 return;
604
605 ttl = PREP_IE_TTL(prep_elem);
606 if (ttl <= 1) {
607 sdata->u.mesh.mshstats.dropped_frames_ttl++;
608 return;
609 }
610
611 rcu_read_lock();
612 mpath = mesh_path_lookup(target_addr, sdata);
613 if (mpath)
614 spin_lock_bh(&mpath->state_lock);
615 else
616 goto fail;
617 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
618 spin_unlock_bh(&mpath->state_lock);
619 goto fail;
620 }
621 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
622 spin_unlock_bh(&mpath->state_lock);
623 --ttl;
624 flags = PREP_IE_FLAGS(prep_elem);
625 lifetime = PREP_IE_LIFETIME(prep_elem);
626 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
627 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
628 target_sn = PREP_IE_TARGET_SN(prep_elem);
629 orig_sn = PREP_IE_ORIG_SN(prep_elem);
630
631 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
632 cpu_to_le32(orig_sn), 0, target_addr,
633 cpu_to_le32(target_sn), next_hop, hopcount,
634 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
635 0, sdata);
636 rcu_read_unlock();
637
638 sdata->u.mesh.mshstats.fwded_unicast++;
639 sdata->u.mesh.mshstats.fwded_frames++;
640 return;
641
642 fail:
643 rcu_read_unlock();
644 sdata->u.mesh.mshstats.dropped_frames_no_route++;
645 }
646
647 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
648 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
649 {
650 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
651 struct mesh_path *mpath;
652 u8 ttl;
653 u8 *ta, *target_addr;
654 u32 target_sn;
655 u16 target_rcode;
656
657 ta = mgmt->sa;
658 ttl = PERR_IE_TTL(perr_elem);
659 if (ttl <= 1) {
660 ifmsh->mshstats.dropped_frames_ttl++;
661 return;
662 }
663 ttl--;
664 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
665 target_sn = PERR_IE_TARGET_SN(perr_elem);
666 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
667
668 rcu_read_lock();
669 mpath = mesh_path_lookup(target_addr, sdata);
670 if (mpath) {
671 spin_lock_bh(&mpath->state_lock);
672 if (mpath->flags & MESH_PATH_ACTIVE &&
673 memcmp(ta, next_hop_deref_protected(mpath)->sta.addr,
674 ETH_ALEN) == 0 &&
675 (!(mpath->flags & MESH_PATH_SN_VALID) ||
676 SN_GT(target_sn, mpath->sn))) {
677 mpath->flags &= ~MESH_PATH_ACTIVE;
678 mpath->sn = target_sn;
679 spin_unlock_bh(&mpath->state_lock);
680 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
681 cpu_to_le16(target_rcode),
682 broadcast_addr, sdata);
683 } else
684 spin_unlock_bh(&mpath->state_lock);
685 }
686 rcu_read_unlock();
687 }
688
689 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
690 struct ieee80211_mgmt *mgmt,
691 struct ieee80211_rann_ie *rann)
692 {
693 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
694 struct mesh_path *mpath;
695 u8 ttl, flags, hopcount;
696 u8 *orig_addr;
697 u32 orig_sn, metric;
698 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
699 bool root_is_gate;
700
701 ttl = rann->rann_ttl;
702 if (ttl <= 1) {
703 ifmsh->mshstats.dropped_frames_ttl++;
704 return;
705 }
706 ttl--;
707 flags = rann->rann_flags;
708 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
709 orig_addr = rann->rann_addr;
710 orig_sn = rann->rann_seq;
711 hopcount = rann->rann_hopcount;
712 hopcount++;
713 metric = rann->rann_metric;
714
715 /* Ignore our own RANNs */
716 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0)
717 return;
718
719 mhwmp_dbg("received RANN from %pM (is_gate=%d)", orig_addr,
720 root_is_gate);
721
722 rcu_read_lock();
723 mpath = mesh_path_lookup(orig_addr, sdata);
724 if (!mpath) {
725 mesh_path_add(orig_addr, sdata);
726 mpath = mesh_path_lookup(orig_addr, sdata);
727 if (!mpath) {
728 rcu_read_unlock();
729 sdata->u.mesh.mshstats.dropped_frames_no_route++;
730 return;
731 }
732 }
733
734 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
735 time_after(jiffies, mpath->exp_time - 1*HZ)) &&
736 !(mpath->flags & MESH_PATH_FIXED)) {
737 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
738 orig_addr);
739 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
740 }
741
742 if (mpath->sn < orig_sn) {
743 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
744 cpu_to_le32(orig_sn),
745 0, NULL, 0, broadcast_addr,
746 hopcount, ttl, cpu_to_le32(interval),
747 cpu_to_le32(metric + mpath->metric),
748 0, sdata);
749 mpath->sn = orig_sn;
750 }
751 if (root_is_gate)
752 mesh_path_add_gate(mpath);
753
754 rcu_read_unlock();
755 }
756
757
758 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
759 struct ieee80211_mgmt *mgmt,
760 size_t len)
761 {
762 struct ieee802_11_elems elems;
763 size_t baselen;
764 u32 last_hop_metric;
765
766 /* need action_code */
767 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
768 return;
769
770 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
771 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
772 len - baselen, &elems);
773
774 if (elems.preq) {
775 if (elems.preq_len != 37)
776 /* Right now we support just 1 destination and no AE */
777 return;
778 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
779 MPATH_PREQ);
780 if (last_hop_metric)
781 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
782 last_hop_metric);
783 }
784 if (elems.prep) {
785 if (elems.prep_len != 31)
786 /* Right now we support no AE */
787 return;
788 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
789 MPATH_PREP);
790 if (last_hop_metric)
791 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
792 last_hop_metric);
793 }
794 if (elems.perr) {
795 if (elems.perr_len != 15)
796 /* Right now we support only one destination per PERR */
797 return;
798 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
799 }
800 if (elems.rann)
801 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
802 }
803
804 /**
805 * mesh_queue_preq - queue a PREQ to a given destination
806 *
807 * @mpath: mesh path to discover
808 * @flags: special attributes of the PREQ to be sent
809 *
810 * Locking: the function must be called from within a rcu read lock block.
811 *
812 */
813 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
814 {
815 struct ieee80211_sub_if_data *sdata = mpath->sdata;
816 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
817 struct mesh_preq_queue *preq_node;
818
819 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
820 if (!preq_node) {
821 mhwmp_dbg("could not allocate PREQ node");
822 return;
823 }
824
825 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
826 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
827 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
828 kfree(preq_node);
829 if (printk_ratelimit())
830 mhwmp_dbg("PREQ node queue full");
831 return;
832 }
833
834 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
835 preq_node->flags = flags;
836
837 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
838 ++ifmsh->preq_queue_len;
839 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
840
841 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
842 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
843
844 else if (time_before(jiffies, ifmsh->last_preq)) {
845 /* avoid long wait if did not send preqs for a long time
846 * and jiffies wrapped around
847 */
848 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
849 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
850 } else
851 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
852 min_preq_int_jiff(sdata));
853 }
854
855 /**
856 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
857 *
858 * @sdata: local mesh subif
859 */
860 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
861 {
862 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
863 struct mesh_preq_queue *preq_node;
864 struct mesh_path *mpath;
865 u8 ttl, target_flags;
866 u32 lifetime;
867
868 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
869 if (!ifmsh->preq_queue_len ||
870 time_before(jiffies, ifmsh->last_preq +
871 min_preq_int_jiff(sdata))) {
872 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
873 return;
874 }
875
876 preq_node = list_first_entry(&ifmsh->preq_queue.list,
877 struct mesh_preq_queue, list);
878 list_del(&preq_node->list);
879 --ifmsh->preq_queue_len;
880 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
881
882 rcu_read_lock();
883 mpath = mesh_path_lookup(preq_node->dst, sdata);
884 if (!mpath)
885 goto enddiscovery;
886
887 spin_lock_bh(&mpath->state_lock);
888 if (preq_node->flags & PREQ_Q_F_START) {
889 if (mpath->flags & MESH_PATH_RESOLVING) {
890 spin_unlock_bh(&mpath->state_lock);
891 goto enddiscovery;
892 } else {
893 mpath->flags &= ~MESH_PATH_RESOLVED;
894 mpath->flags |= MESH_PATH_RESOLVING;
895 mpath->discovery_retries = 0;
896 mpath->discovery_timeout = disc_timeout_jiff(sdata);
897 }
898 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
899 mpath->flags & MESH_PATH_RESOLVED) {
900 mpath->flags &= ~MESH_PATH_RESOLVING;
901 spin_unlock_bh(&mpath->state_lock);
902 goto enddiscovery;
903 }
904
905 ifmsh->last_preq = jiffies;
906
907 if (time_after(jiffies, ifmsh->last_sn_update +
908 net_traversal_jiffies(sdata)) ||
909 time_before(jiffies, ifmsh->last_sn_update)) {
910 ++ifmsh->sn;
911 sdata->u.mesh.last_sn_update = jiffies;
912 }
913 lifetime = default_lifetime(sdata);
914 ttl = sdata->u.mesh.mshcfg.element_ttl;
915 if (ttl == 0) {
916 sdata->u.mesh.mshstats.dropped_frames_ttl++;
917 spin_unlock_bh(&mpath->state_lock);
918 goto enddiscovery;
919 }
920
921 if (preq_node->flags & PREQ_Q_F_REFRESH)
922 target_flags = MP_F_DO;
923 else
924 target_flags = MP_F_RF;
925
926 spin_unlock_bh(&mpath->state_lock);
927 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
928 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
929 cpu_to_le32(mpath->sn), broadcast_addr, 0,
930 ttl, cpu_to_le32(lifetime), 0,
931 cpu_to_le32(ifmsh->preq_id++), sdata);
932 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
933
934 enddiscovery:
935 rcu_read_unlock();
936 kfree(preq_node);
937 }
938
939 /**
940 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
941 *
942 * @skb: 802.11 frame to be sent
943 * @sdata: network subif the frame will be sent through
944 *
945 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
946 * found, the function will start a path discovery and queue the frame so it is
947 * sent when the path is resolved. This means the caller must not free the skb
948 * in this case.
949 */
950 int mesh_nexthop_lookup(struct sk_buff *skb,
951 struct ieee80211_sub_if_data *sdata)
952 {
953 struct sk_buff *skb_to_free = NULL;
954 struct mesh_path *mpath;
955 struct sta_info *next_hop;
956 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
957 u8 *target_addr = hdr->addr3;
958 int err = 0;
959
960 rcu_read_lock();
961 mpath = mesh_path_lookup(target_addr, sdata);
962
963 if (!mpath) {
964 mesh_path_add(target_addr, sdata);
965 mpath = mesh_path_lookup(target_addr, sdata);
966 if (!mpath) {
967 sdata->u.mesh.mshstats.dropped_frames_no_route++;
968 err = -ENOSPC;
969 goto endlookup;
970 }
971 }
972
973 if (mpath->flags & MESH_PATH_ACTIVE) {
974 if (time_after(jiffies,
975 mpath->exp_time -
976 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
977 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) &&
978 !(mpath->flags & MESH_PATH_RESOLVING) &&
979 !(mpath->flags & MESH_PATH_FIXED)) {
980 mesh_queue_preq(mpath,
981 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
982 }
983 next_hop = rcu_dereference(mpath->next_hop);
984 if (next_hop)
985 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
986 else
987 err = -ENOENT;
988 } else {
989 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
990 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
991 /* Start discovery only if it is not running yet */
992 mesh_queue_preq(mpath, PREQ_Q_F_START);
993 }
994
995 if (skb_queue_len(&mpath->frame_queue) >=
996 MESH_FRAME_QUEUE_LEN)
997 skb_to_free = skb_dequeue(&mpath->frame_queue);
998
999 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1000 skb_queue_tail(&mpath->frame_queue, skb);
1001 if (skb_to_free)
1002 mesh_path_discard_frame(skb_to_free, sdata);
1003 err = -ENOENT;
1004 }
1005
1006 endlookup:
1007 rcu_read_unlock();
1008 return err;
1009 }
1010
1011 void mesh_path_timer(unsigned long data)
1012 {
1013 struct mesh_path *mpath = (void *) data;
1014 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1015 int ret;
1016
1017 if (sdata->local->quiescing)
1018 return;
1019
1020 spin_lock_bh(&mpath->state_lock);
1021 if (mpath->flags & MESH_PATH_RESOLVED ||
1022 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1023 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1024 spin_unlock_bh(&mpath->state_lock);
1025 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1026 ++mpath->discovery_retries;
1027 mpath->discovery_timeout *= 2;
1028 spin_unlock_bh(&mpath->state_lock);
1029 mesh_queue_preq(mpath, 0);
1030 } else {
1031 mpath->flags = 0;
1032 mpath->exp_time = jiffies;
1033 spin_unlock_bh(&mpath->state_lock);
1034 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1035 ret = mesh_path_send_to_gates(mpath);
1036 if (ret)
1037 mhwmp_dbg("no gate was reachable");
1038 } else
1039 mesh_path_flush_pending(mpath);
1040 }
1041 }
1042
1043 void
1044 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1045 {
1046 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1047 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1048 u8 flags;
1049
1050 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1051 ? RANN_FLAG_IS_GATE : 0;
1052 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1053 cpu_to_le32(++ifmsh->sn),
1054 0, NULL, 0, broadcast_addr,
1055 0, sdata->u.mesh.mshcfg.element_ttl,
1056 cpu_to_le32(interval), 0, 0, sdata);
1057 }
linux-next