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Merge v3.2-rc4 into usb-next
[zen-stable.git] / net / mac80211 / mesh_hwmp.c
blob174040a42887c3eaf1d466fcfcf003ab83bd248d
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 "wme.h"
12 #include "mesh.h"
13
14 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG
15 #define mhwmp_dbg(fmt, args...) \
16 printk(KERN_DEBUG "Mesh HWMP (%s): " fmt "\n", sdata->name, ##args)
17 #else
18 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0)
19 #endif
20
21 #define TEST_FRAME_LEN 8192
22 #define MAX_METRIC 0xffffffff
23 #define ARITH_SHIFT 8
24
25 /* Number of frames buffered per destination for unresolved destinations */
26 #define MESH_FRAME_QUEUE_LEN 10
27 #define MAX_PREQ_QUEUE_LEN 64
28
29 /* Destination only */
30 #define MP_F_DO 0x1
31 /* Reply and forward */
32 #define MP_F_RF 0x2
33 /* Unknown Sequence Number */
34 #define MP_F_USN 0x01
35 /* Reason code Present */
36 #define MP_F_RCODE 0x02
37
38 static void mesh_queue_preq(struct mesh_path *, u8);
39
40 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
41 {
42 if (ae)
43 offset += 6;
44 return get_unaligned_le32(preq_elem + offset);
45 }
46
47 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
48 {
49 if (ae)
50 offset += 6;
51 return get_unaligned_le16(preq_elem + offset);
52 }
53
54 /* HWMP IE processing macros */
55 #define AE_F (1<<6)
56 #define AE_F_SET(x) (*x & AE_F)
57 #define PREQ_IE_FLAGS(x) (*(x))
58 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
59 #define PREQ_IE_TTL(x) (*(x + 2))
60 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
61 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
62 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
63 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
64 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
65 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
66 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
67 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
68
69
70 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
71 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
72 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
73 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
74 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
75 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
76 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
77 #define PREP_IE_TARGET_ADDR(x) (x + 3)
78 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
79
80 #define PERR_IE_TTL(x) (*(x))
81 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
82 #define PERR_IE_TARGET_ADDR(x) (x + 3)
83 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
84 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
85
86 #define MSEC_TO_TU(x) (x*1000/1024)
87 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0)
88 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0)
89
90 #define net_traversal_jiffies(s) \
91 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
92 #define default_lifetime(s) \
93 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
94 #define min_preq_int_jiff(s) \
95 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
96 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
97 #define disc_timeout_jiff(s) \
98 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
99
100 enum mpath_frame_type {
101 MPATH_PREQ = 0,
102 MPATH_PREP,
103 MPATH_PERR,
104 MPATH_RANN
105 };
106
107 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
108
109 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
110 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target,
111 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl,
112 __le32 lifetime, __le32 metric, __le32 preq_id,
113 struct ieee80211_sub_if_data *sdata)
114 {
115 struct ieee80211_local *local = sdata->local;
116 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
117 struct ieee80211_mgmt *mgmt;
118 u8 *pos;
119 int ie_len;
120
121 if (!skb)
122 return -1;
123 skb_reserve(skb, local->hw.extra_tx_headroom);
124 /* 25 is the size of the common mgmt part (24) plus the size of the
125 * common action part (1)
126 */
127 mgmt = (struct ieee80211_mgmt *)
128 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
129 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
130 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
131 IEEE80211_STYPE_ACTION);
132
133 memcpy(mgmt->da, da, ETH_ALEN);
134 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
135 /* BSSID == SA */
136 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
137 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
138 mgmt->u.action.u.mesh_action.action_code =
139 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
140
141 switch (action) {
142 case MPATH_PREQ:
143 mhwmp_dbg("sending PREQ to %pM", target);
144 ie_len = 37;
145 pos = skb_put(skb, 2 + ie_len);
146 *pos++ = WLAN_EID_PREQ;
147 break;
148 case MPATH_PREP:
149 mhwmp_dbg("sending PREP to %pM", target);
150 ie_len = 31;
151 pos = skb_put(skb, 2 + ie_len);
152 *pos++ = WLAN_EID_PREP;
153 break;
154 case MPATH_RANN:
155 mhwmp_dbg("sending RANN from %pM", orig_addr);
156 ie_len = sizeof(struct ieee80211_rann_ie);
157 pos = skb_put(skb, 2 + ie_len);
158 *pos++ = WLAN_EID_RANN;
159 break;
160 default:
161 kfree_skb(skb);
162 return -ENOTSUPP;
163 break;
164 }
165 *pos++ = ie_len;
166 *pos++ = flags;
167 *pos++ = hop_count;
168 *pos++ = ttl;
169 if (action == MPATH_PREP) {
170 memcpy(pos, target, ETH_ALEN);
171 pos += ETH_ALEN;
172 memcpy(pos, &target_sn, 4);
173 pos += 4;
174 } else {
175 if (action == MPATH_PREQ) {
176 memcpy(pos, &preq_id, 4);
177 pos += 4;
178 }
179 memcpy(pos, orig_addr, ETH_ALEN);
180 pos += ETH_ALEN;
181 memcpy(pos, &orig_sn, 4);
182 pos += 4;
183 }
184 memcpy(pos, &lifetime, 4); /* interval for RANN */
185 pos += 4;
186 memcpy(pos, &metric, 4);
187 pos += 4;
188 if (action == MPATH_PREQ) {
189 *pos++ = 1; /* destination count */
190 *pos++ = target_flags;
191 memcpy(pos, target, ETH_ALEN);
192 pos += ETH_ALEN;
193 memcpy(pos, &target_sn, 4);
194 pos += 4;
195 } else if (action == MPATH_PREP) {
196 memcpy(pos, orig_addr, ETH_ALEN);
197 pos += ETH_ALEN;
198 memcpy(pos, &orig_sn, 4);
199 pos += 4;
200 }
201
202 ieee80211_tx_skb(sdata, skb);
203 return 0;
204 }
205
206
207 /* Headroom is not adjusted. Caller should ensure that skb has sufficient
208 * headroom in case the frame is encrypted. */
209 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
210 struct sk_buff *skb)
211 {
212 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
213
214 skb_set_mac_header(skb, 0);
215 skb_set_network_header(skb, 0);
216 skb_set_transport_header(skb, 0);
217
218 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
219 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
220 skb->priority = 7;
221
222 info->control.vif = &sdata->vif;
223 ieee80211_set_qos_hdr(sdata, skb);
224 }
225
226 /**
227 * mesh_send_path error - Sends a PERR mesh management frame
228 *
229 * @target: broken destination
230 * @target_sn: SN of the broken destination
231 * @target_rcode: reason code for this PERR
232 * @ra: node this frame is addressed to
233 *
234 * Note: This function may be called with driver locks taken that the driver
235 * also acquires in the TX path. To avoid a deadlock we don't transmit the
236 * frame directly but add it to the pending queue instead.
237 */
238 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
239 __le16 target_rcode, const u8 *ra,
240 struct ieee80211_sub_if_data *sdata)
241 {
242 struct ieee80211_local *local = sdata->local;
243 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
244 struct ieee80211_mgmt *mgmt;
245 u8 *pos;
246 int ie_len;
247
248 if (!skb)
249 return -1;
250 skb_reserve(skb, local->tx_headroom + local->hw.extra_tx_headroom);
251 /* 25 is the size of the common mgmt part (24) plus the size of the
252 * common action part (1)
253 */
254 mgmt = (struct ieee80211_mgmt *)
255 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
256 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
257 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
258 IEEE80211_STYPE_ACTION);
259
260 memcpy(mgmt->da, ra, ETH_ALEN);
261 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
262 /* BSSID == SA */
263 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
264 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
265 mgmt->u.action.u.mesh_action.action_code =
266 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
267 ie_len = 15;
268 pos = skb_put(skb, 2 + ie_len);
269 *pos++ = WLAN_EID_PERR;
270 *pos++ = ie_len;
271 /* ttl */
272 *pos++ = ttl;
273 /* number of destinations */
274 *pos++ = 1;
275 /*
276 * flags bit, bit 1 is unset if we know the sequence number and
277 * bit 2 is set if we have a reason code
278 */
279 *pos = 0;
280 if (!target_sn)
281 *pos |= MP_F_USN;
282 if (target_rcode)
283 *pos |= MP_F_RCODE;
284 pos++;
285 memcpy(pos, target, ETH_ALEN);
286 pos += ETH_ALEN;
287 memcpy(pos, &target_sn, 4);
288 pos += 4;
289 memcpy(pos, &target_rcode, 2);
290
291 /* see note in function header */
292 prepare_frame_for_deferred_tx(sdata, skb);
293 ieee80211_add_pending_skb(local, skb);
294 return 0;
295 }
296
297 void ieee80211s_update_metric(struct ieee80211_local *local,
298 struct sta_info *stainfo, struct sk_buff *skb)
299 {
300 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
301 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
302 int failed;
303
304 if (!ieee80211_is_data(hdr->frame_control))
305 return;
306
307 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
308
309 /* moving average, scaled to 100 */
310 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
311 if (stainfo->fail_avg > 95)
312 mesh_plink_broken(stainfo);
313 }
314
315 static u32 airtime_link_metric_get(struct ieee80211_local *local,
316 struct sta_info *sta)
317 {
318 struct ieee80211_supported_band *sband;
319 /* This should be adjusted for each device */
320 int device_constant = 1 << ARITH_SHIFT;
321 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
322 int s_unit = 1 << ARITH_SHIFT;
323 int rate, err;
324 u32 tx_time, estimated_retx;
325 u64 result;
326
327 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
328
329 if (sta->fail_avg >= 100)
330 return MAX_METRIC;
331
332 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
333 return MAX_METRIC;
334
335 err = (sta->fail_avg << ARITH_SHIFT) / 100;
336
337 /* bitrate is in units of 100 Kbps, while we need rate in units of
338 * 1Mbps. This will be corrected on tx_time computation.
339 */
340 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
341 tx_time = (device_constant + 10 * test_frame_len / rate);
342 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
343 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
344 return (u32)result;
345 }
346
347 /**
348 * hwmp_route_info_get - Update routing info to originator and transmitter
349 *
350 * @sdata: local mesh subif
351 * @mgmt: mesh management frame
352 * @hwmp_ie: hwmp information element (PREP or PREQ)
353 *
354 * This function updates the path routing information to the originator and the
355 * transmitter of a HWMP PREQ or PREP frame.
356 *
357 * Returns: metric to frame originator or 0 if the frame should not be further
358 * processed
359 *
360 * Notes: this function is the only place (besides user-provided info) where
361 * path routing information is updated.
362 */
363 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
364 struct ieee80211_mgmt *mgmt,
365 u8 *hwmp_ie, enum mpath_frame_type action)
366 {
367 struct ieee80211_local *local = sdata->local;
368 struct mesh_path *mpath;
369 struct sta_info *sta;
370 bool fresh_info;
371 u8 *orig_addr, *ta;
372 u32 orig_sn, orig_metric;
373 unsigned long orig_lifetime, exp_time;
374 u32 last_hop_metric, new_metric;
375 bool process = true;
376
377 rcu_read_lock();
378 sta = sta_info_get(sdata, mgmt->sa);
379 if (!sta) {
380 rcu_read_unlock();
381 return 0;
382 }
383
384 last_hop_metric = airtime_link_metric_get(local, sta);
385 /* Update and check originator routing info */
386 fresh_info = true;
387
388 switch (action) {
389 case MPATH_PREQ:
390 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
391 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
392 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
393 orig_metric = PREQ_IE_METRIC(hwmp_ie);
394 break;
395 case MPATH_PREP:
396 /* Originator here refers to the MP that was the destination in
397 * the Path Request. The draft refers to that MP as the
398 * destination address, even though usually it is the origin of
399 * the PREP frame. We divert from the nomenclature in the draft
400 * so that we can easily use a single function to gather path
401 * information from both PREQ and PREP frames.
402 */
403 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
404 orig_sn = PREP_IE_ORIG_SN(hwmp_ie);
405 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
406 orig_metric = PREP_IE_METRIC(hwmp_ie);
407 break;
408 default:
409 rcu_read_unlock();
410 return 0;
411 }
412 new_metric = orig_metric + last_hop_metric;
413 if (new_metric < orig_metric)
414 new_metric = MAX_METRIC;
415 exp_time = TU_TO_EXP_TIME(orig_lifetime);
416
417 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) {
418 /* This MP is the originator, we are not interested in this
419 * frame, except for updating transmitter's path info.
420 */
421 process = false;
422 fresh_info = false;
423 } else {
424 mpath = mesh_path_lookup(orig_addr, sdata);
425 if (mpath) {
426 spin_lock_bh(&mpath->state_lock);
427 if (mpath->flags & MESH_PATH_FIXED)
428 fresh_info = false;
429 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
430 (mpath->flags & MESH_PATH_SN_VALID)) {
431 if (SN_GT(mpath->sn, orig_sn) ||
432 (mpath->sn == orig_sn &&
433 new_metric >= mpath->metric)) {
434 process = false;
435 fresh_info = false;
436 }
437 }
438 } else {
439 mesh_path_add(orig_addr, sdata);
440 mpath = mesh_path_lookup(orig_addr, sdata);
441 if (!mpath) {
442 rcu_read_unlock();
443 return 0;
444 }
445 spin_lock_bh(&mpath->state_lock);
446 }
447
448 if (fresh_info) {
449 mesh_path_assign_nexthop(mpath, sta);
450 mpath->flags |= MESH_PATH_SN_VALID;
451 mpath->metric = new_metric;
452 mpath->sn = orig_sn;
453 mpath->exp_time = time_after(mpath->exp_time, exp_time)
454 ? mpath->exp_time : exp_time;
455 mesh_path_activate(mpath);
456 spin_unlock_bh(&mpath->state_lock);
457 mesh_path_tx_pending(mpath);
458 /* draft says preq_id should be saved to, but there does
459 * not seem to be any use for it, skipping by now
460 */
461 } else
462 spin_unlock_bh(&mpath->state_lock);
463 }
464
465 /* Update and check transmitter routing info */
466 ta = mgmt->sa;
467 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
468 fresh_info = false;
469 else {
470 fresh_info = true;
471
472 mpath = mesh_path_lookup(ta, sdata);
473 if (mpath) {
474 spin_lock_bh(&mpath->state_lock);
475 if ((mpath->flags & MESH_PATH_FIXED) ||
476 ((mpath->flags & MESH_PATH_ACTIVE) &&
477 (last_hop_metric > mpath->metric)))
478 fresh_info = false;
479 } else {
480 mesh_path_add(ta, sdata);
481 mpath = mesh_path_lookup(ta, sdata);
482 if (!mpath) {
483 rcu_read_unlock();
484 return 0;
485 }
486 spin_lock_bh(&mpath->state_lock);
487 }
488
489 if (fresh_info) {
490 mesh_path_assign_nexthop(mpath, sta);
491 mpath->metric = last_hop_metric;
492 mpath->exp_time = time_after(mpath->exp_time, exp_time)
493 ? mpath->exp_time : exp_time;
494 mesh_path_activate(mpath);
495 spin_unlock_bh(&mpath->state_lock);
496 mesh_path_tx_pending(mpath);
497 } else
498 spin_unlock_bh(&mpath->state_lock);
499 }
500
501 rcu_read_unlock();
502
503 return process ? new_metric : 0;
504 }
505
506 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
507 struct ieee80211_mgmt *mgmt,
508 u8 *preq_elem, u32 metric)
509 {
510 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
511 struct mesh_path *mpath;
512 u8 *target_addr, *orig_addr;
513 u8 target_flags, ttl;
514 u32 orig_sn, target_sn, lifetime;
515 bool reply = false;
516 bool forward = true;
517
518 /* Update target SN, if present */
519 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
520 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
521 target_sn = PREQ_IE_TARGET_SN(preq_elem);
522 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
523 target_flags = PREQ_IE_TARGET_F(preq_elem);
524
525 mhwmp_dbg("received PREQ from %pM", orig_addr);
526
527 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) {
528 mhwmp_dbg("PREQ is for us");
529 forward = false;
530 reply = true;
531 metric = 0;
532 if (time_after(jiffies, ifmsh->last_sn_update +
533 net_traversal_jiffies(sdata)) ||
534 time_before(jiffies, ifmsh->last_sn_update)) {
535 target_sn = ++ifmsh->sn;
536 ifmsh->last_sn_update = jiffies;
537 }
538 } else {
539 rcu_read_lock();
540 mpath = mesh_path_lookup(target_addr, sdata);
541 if (mpath) {
542 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
543 SN_LT(mpath->sn, target_sn)) {
544 mpath->sn = target_sn;
545 mpath->flags |= MESH_PATH_SN_VALID;
546 } else if ((!(target_flags & MP_F_DO)) &&
547 (mpath->flags & MESH_PATH_ACTIVE)) {
548 reply = true;
549 metric = mpath->metric;
550 target_sn = mpath->sn;
551 if (target_flags & MP_F_RF)
552 target_flags |= MP_F_DO;
553 else
554 forward = false;
555 }
556 }
557 rcu_read_unlock();
558 }
559
560 if (reply) {
561 lifetime = PREQ_IE_LIFETIME(preq_elem);
562 ttl = ifmsh->mshcfg.element_ttl;
563 if (ttl != 0) {
564 mhwmp_dbg("replying to the PREQ");
565 mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr,
566 cpu_to_le32(target_sn), 0, orig_addr,
567 cpu_to_le32(orig_sn), mgmt->sa, 0, ttl,
568 cpu_to_le32(lifetime), cpu_to_le32(metric),
569 0, sdata);
570 } else
571 ifmsh->mshstats.dropped_frames_ttl++;
572 }
573
574 if (forward) {
575 u32 preq_id;
576 u8 hopcount, flags;
577
578 ttl = PREQ_IE_TTL(preq_elem);
579 lifetime = PREQ_IE_LIFETIME(preq_elem);
580 if (ttl <= 1) {
581 ifmsh->mshstats.dropped_frames_ttl++;
582 return;
583 }
584 mhwmp_dbg("forwarding the PREQ from %pM", orig_addr);
585 --ttl;
586 flags = PREQ_IE_FLAGS(preq_elem);
587 preq_id = PREQ_IE_PREQ_ID(preq_elem);
588 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
589 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
590 cpu_to_le32(orig_sn), target_flags, target_addr,
591 cpu_to_le32(target_sn), broadcast_addr,
592 hopcount, ttl, cpu_to_le32(lifetime),
593 cpu_to_le32(metric), cpu_to_le32(preq_id),
594 sdata);
595 ifmsh->mshstats.fwded_mcast++;
596 ifmsh->mshstats.fwded_frames++;
597 }
598 }
599
600
601 static inline struct sta_info *
602 next_hop_deref_protected(struct mesh_path *mpath)
603 {
604 return rcu_dereference_protected(mpath->next_hop,
605 lockdep_is_held(&mpath->state_lock));
606 }
607
608
609 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
610 struct ieee80211_mgmt *mgmt,
611 u8 *prep_elem, u32 metric)
612 {
613 struct mesh_path *mpath;
614 u8 *target_addr, *orig_addr;
615 u8 ttl, hopcount, flags;
616 u8 next_hop[ETH_ALEN];
617 u32 target_sn, orig_sn, lifetime;
618
619 mhwmp_dbg("received PREP from %pM", PREP_IE_ORIG_ADDR(prep_elem));
620
621 /* Note that we divert from the draft nomenclature and denominate
622 * destination to what the draft refers to as origininator. So in this
623 * function destnation refers to the final destination of the PREP,
624 * which corresponds with the originator of the PREQ which this PREP
625 * replies
626 */
627 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
628 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0)
629 /* destination, no forwarding required */
630 return;
631
632 ttl = PREP_IE_TTL(prep_elem);
633 if (ttl <= 1) {
634 sdata->u.mesh.mshstats.dropped_frames_ttl++;
635 return;
636 }
637
638 rcu_read_lock();
639 mpath = mesh_path_lookup(target_addr, sdata);
640 if (mpath)
641 spin_lock_bh(&mpath->state_lock);
642 else
643 goto fail;
644 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
645 spin_unlock_bh(&mpath->state_lock);
646 goto fail;
647 }
648 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
649 spin_unlock_bh(&mpath->state_lock);
650 --ttl;
651 flags = PREP_IE_FLAGS(prep_elem);
652 lifetime = PREP_IE_LIFETIME(prep_elem);
653 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
654 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
655 target_sn = PREP_IE_TARGET_SN(prep_elem);
656 orig_sn = PREP_IE_ORIG_SN(prep_elem);
657
658 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
659 cpu_to_le32(orig_sn), 0, target_addr,
660 cpu_to_le32(target_sn), next_hop, hopcount,
661 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
662 0, sdata);
663 rcu_read_unlock();
664
665 sdata->u.mesh.mshstats.fwded_unicast++;
666 sdata->u.mesh.mshstats.fwded_frames++;
667 return;
668
669 fail:
670 rcu_read_unlock();
671 sdata->u.mesh.mshstats.dropped_frames_no_route++;
672 }
673
674 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
675 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
676 {
677 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
678 struct mesh_path *mpath;
679 u8 ttl;
680 u8 *ta, *target_addr;
681 u32 target_sn;
682 u16 target_rcode;
683
684 ta = mgmt->sa;
685 ttl = PERR_IE_TTL(perr_elem);
686 if (ttl <= 1) {
687 ifmsh->mshstats.dropped_frames_ttl++;
688 return;
689 }
690 ttl--;
691 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
692 target_sn = PERR_IE_TARGET_SN(perr_elem);
693 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
694
695 rcu_read_lock();
696 mpath = mesh_path_lookup(target_addr, sdata);
697 if (mpath) {
698 spin_lock_bh(&mpath->state_lock);
699 if (mpath->flags & MESH_PATH_ACTIVE &&
700 memcmp(ta, next_hop_deref_protected(mpath)->sta.addr,
701 ETH_ALEN) == 0 &&
702 (!(mpath->flags & MESH_PATH_SN_VALID) ||
703 SN_GT(target_sn, mpath->sn))) {
704 mpath->flags &= ~MESH_PATH_ACTIVE;
705 mpath->sn = target_sn;
706 spin_unlock_bh(&mpath->state_lock);
707 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
708 cpu_to_le16(target_rcode),
709 broadcast_addr, sdata);
710 } else
711 spin_unlock_bh(&mpath->state_lock);
712 }
713 rcu_read_unlock();
714 }
715
716 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
717 struct ieee80211_mgmt *mgmt,
718 struct ieee80211_rann_ie *rann)
719 {
720 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
721 struct mesh_path *mpath;
722 u8 ttl, flags, hopcount;
723 u8 *orig_addr;
724 u32 orig_sn, metric;
725 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
726 bool root_is_gate;
727
728 ttl = rann->rann_ttl;
729 if (ttl <= 1) {
730 ifmsh->mshstats.dropped_frames_ttl++;
731 return;
732 }
733 ttl--;
734 flags = rann->rann_flags;
735 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
736 orig_addr = rann->rann_addr;
737 orig_sn = rann->rann_seq;
738 hopcount = rann->rann_hopcount;
739 hopcount++;
740 metric = rann->rann_metric;
741
742 /* Ignore our own RANNs */
743 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0)
744 return;
745
746 mhwmp_dbg("received RANN from %pM (is_gate=%d)", orig_addr,
747 root_is_gate);
748
749 rcu_read_lock();
750 mpath = mesh_path_lookup(orig_addr, sdata);
751 if (!mpath) {
752 mesh_path_add(orig_addr, sdata);
753 mpath = mesh_path_lookup(orig_addr, sdata);
754 if (!mpath) {
755 rcu_read_unlock();
756 sdata->u.mesh.mshstats.dropped_frames_no_route++;
757 return;
758 }
759 }
760
761 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
762 time_after(jiffies, mpath->exp_time - 1*HZ)) &&
763 !(mpath->flags & MESH_PATH_FIXED)) {
764 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
765 orig_addr);
766 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
767 }
768
769 if (mpath->sn < orig_sn) {
770 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
771 cpu_to_le32(orig_sn),
772 0, NULL, 0, broadcast_addr,
773 hopcount, ttl, cpu_to_le32(interval),
774 cpu_to_le32(metric + mpath->metric),
775 0, sdata);
776 mpath->sn = orig_sn;
777 }
778 if (root_is_gate)
779 mesh_path_add_gate(mpath);
780
781 rcu_read_unlock();
782 }
783
784
785 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
786 struct ieee80211_mgmt *mgmt,
787 size_t len)
788 {
789 struct ieee802_11_elems elems;
790 size_t baselen;
791 u32 last_hop_metric;
792 struct sta_info *sta;
793
794 /* need action_code */
795 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
796 return;
797
798 rcu_read_lock();
799 sta = sta_info_get(sdata, mgmt->sa);
800 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) {
801 rcu_read_unlock();
802 return;
803 }
804 rcu_read_unlock();
805
806 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
807 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
808 len - baselen, &elems);
809
810 if (elems.preq) {
811 if (elems.preq_len != 37)
812 /* Right now we support just 1 destination and no AE */
813 return;
814 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
815 MPATH_PREQ);
816 if (last_hop_metric)
817 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
818 last_hop_metric);
819 }
820 if (elems.prep) {
821 if (elems.prep_len != 31)
822 /* Right now we support no AE */
823 return;
824 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
825 MPATH_PREP);
826 if (last_hop_metric)
827 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
828 last_hop_metric);
829 }
830 if (elems.perr) {
831 if (elems.perr_len != 15)
832 /* Right now we support only one destination per PERR */
833 return;
834 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
835 }
836 if (elems.rann)
837 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
838 }
839
840 /**
841 * mesh_queue_preq - queue a PREQ to a given destination
842 *
843 * @mpath: mesh path to discover
844 * @flags: special attributes of the PREQ to be sent
845 *
846 * Locking: the function must be called from within a rcu read lock block.
847 *
848 */
849 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
850 {
851 struct ieee80211_sub_if_data *sdata = mpath->sdata;
852 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
853 struct mesh_preq_queue *preq_node;
854
855 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
856 if (!preq_node) {
857 mhwmp_dbg("could not allocate PREQ node");
858 return;
859 }
860
861 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
862 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
863 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
864 kfree(preq_node);
865 if (printk_ratelimit())
866 mhwmp_dbg("PREQ node queue full");
867 return;
868 }
869
870 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
871 preq_node->flags = flags;
872
873 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
874 ++ifmsh->preq_queue_len;
875 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
876
877 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
878 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
879
880 else if (time_before(jiffies, ifmsh->last_preq)) {
881 /* avoid long wait if did not send preqs for a long time
882 * and jiffies wrapped around
883 */
884 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
885 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
886 } else
887 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
888 min_preq_int_jiff(sdata));
889 }
890
891 /**
892 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
893 *
894 * @sdata: local mesh subif
895 */
896 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
897 {
898 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
899 struct mesh_preq_queue *preq_node;
900 struct mesh_path *mpath;
901 u8 ttl, target_flags;
902 u32 lifetime;
903
904 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
905 if (!ifmsh->preq_queue_len ||
906 time_before(jiffies, ifmsh->last_preq +
907 min_preq_int_jiff(sdata))) {
908 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
909 return;
910 }
911
912 preq_node = list_first_entry(&ifmsh->preq_queue.list,
913 struct mesh_preq_queue, list);
914 list_del(&preq_node->list);
915 --ifmsh->preq_queue_len;
916 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
917
918 rcu_read_lock();
919 mpath = mesh_path_lookup(preq_node->dst, sdata);
920 if (!mpath)
921 goto enddiscovery;
922
923 spin_lock_bh(&mpath->state_lock);
924 if (preq_node->flags & PREQ_Q_F_START) {
925 if (mpath->flags & MESH_PATH_RESOLVING) {
926 spin_unlock_bh(&mpath->state_lock);
927 goto enddiscovery;
928 } else {
929 mpath->flags &= ~MESH_PATH_RESOLVED;
930 mpath->flags |= MESH_PATH_RESOLVING;
931 mpath->discovery_retries = 0;
932 mpath->discovery_timeout = disc_timeout_jiff(sdata);
933 }
934 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
935 mpath->flags & MESH_PATH_RESOLVED) {
936 mpath->flags &= ~MESH_PATH_RESOLVING;
937 spin_unlock_bh(&mpath->state_lock);
938 goto enddiscovery;
939 }
940
941 ifmsh->last_preq = jiffies;
942
943 if (time_after(jiffies, ifmsh->last_sn_update +
944 net_traversal_jiffies(sdata)) ||
945 time_before(jiffies, ifmsh->last_sn_update)) {
946 ++ifmsh->sn;
947 sdata->u.mesh.last_sn_update = jiffies;
948 }
949 lifetime = default_lifetime(sdata);
950 ttl = sdata->u.mesh.mshcfg.element_ttl;
951 if (ttl == 0) {
952 sdata->u.mesh.mshstats.dropped_frames_ttl++;
953 spin_unlock_bh(&mpath->state_lock);
954 goto enddiscovery;
955 }
956
957 if (preq_node->flags & PREQ_Q_F_REFRESH)
958 target_flags = MP_F_DO;
959 else
960 target_flags = MP_F_RF;
961
962 spin_unlock_bh(&mpath->state_lock);
963 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
964 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
965 cpu_to_le32(mpath->sn), broadcast_addr, 0,
966 ttl, cpu_to_le32(lifetime), 0,
967 cpu_to_le32(ifmsh->preq_id++), sdata);
968 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
969
970 enddiscovery:
971 rcu_read_unlock();
972 kfree(preq_node);
973 }
974
975 /**
976 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
977 *
978 * @skb: 802.11 frame to be sent
979 * @sdata: network subif the frame will be sent through
980 *
981 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
982 * found, the function will start a path discovery and queue the frame so it is
983 * sent when the path is resolved. This means the caller must not free the skb
984 * in this case.
985 */
986 int mesh_nexthop_lookup(struct sk_buff *skb,
987 struct ieee80211_sub_if_data *sdata)
988 {
989 struct sk_buff *skb_to_free = NULL;
990 struct mesh_path *mpath;
991 struct sta_info *next_hop;
992 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
993 u8 *target_addr = hdr->addr3;
994 int err = 0;
995
996 rcu_read_lock();
997 mpath = mesh_path_lookup(target_addr, sdata);
998
999 if (!mpath) {
1000 mesh_path_add(target_addr, sdata);
1001 mpath = mesh_path_lookup(target_addr, sdata);
1002 if (!mpath) {
1003 sdata->u.mesh.mshstats.dropped_frames_no_route++;
1004 err = -ENOSPC;
1005 goto endlookup;
1006 }
1007 }
1008
1009 if (mpath->flags & MESH_PATH_ACTIVE) {
1010 if (time_after(jiffies,
1011 mpath->exp_time -
1012 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1013 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) &&
1014 !(mpath->flags & MESH_PATH_RESOLVING) &&
1015 !(mpath->flags & MESH_PATH_FIXED)) {
1016 mesh_queue_preq(mpath,
1017 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1018 }
1019 next_hop = rcu_dereference(mpath->next_hop);
1020 if (next_hop)
1021 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1022 else
1023 err = -ENOENT;
1024 } else {
1025 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1026 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
1027 /* Start discovery only if it is not running yet */
1028 mesh_queue_preq(mpath, PREQ_Q_F_START);
1029 }
1030
1031 if (skb_queue_len(&mpath->frame_queue) >=
1032 MESH_FRAME_QUEUE_LEN)
1033 skb_to_free = skb_dequeue(&mpath->frame_queue);
1034
1035 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1036 skb_queue_tail(&mpath->frame_queue, skb);
1037 if (skb_to_free)
1038 mesh_path_discard_frame(skb_to_free, sdata);
1039 err = -ENOENT;
1040 }
1041
1042 endlookup:
1043 rcu_read_unlock();
1044 return err;
1045 }
1046
1047 void mesh_path_timer(unsigned long data)
1048 {
1049 struct mesh_path *mpath = (void *) data;
1050 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1051 int ret;
1052
1053 if (sdata->local->quiescing)
1054 return;
1055
1056 spin_lock_bh(&mpath->state_lock);
1057 if (mpath->flags & MESH_PATH_RESOLVED ||
1058 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1059 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1060 spin_unlock_bh(&mpath->state_lock);
1061 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1062 ++mpath->discovery_retries;
1063 mpath->discovery_timeout *= 2;
1064 spin_unlock_bh(&mpath->state_lock);
1065 mesh_queue_preq(mpath, 0);
1066 } else {
1067 mpath->flags = 0;
1068 mpath->exp_time = jiffies;
1069 spin_unlock_bh(&mpath->state_lock);
1070 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1071 ret = mesh_path_send_to_gates(mpath);
1072 if (ret)
1073 mhwmp_dbg("no gate was reachable");
1074 } else
1075 mesh_path_flush_pending(mpath);
1076 }
1077 }
1078
1079 void
1080 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1081 {
1082 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1083 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1084 u8 flags;
1085
1086 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1087 ? RANN_FLAG_IS_GATE : 0;
1088 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1089 cpu_to_le32(++ifmsh->sn),
1090 0, NULL, 0, broadcast_addr,
1091 0, sdata->u.mesh.mshcfg.element_ttl,
1092 cpu_to_le32(interval), 0, 0, sdata);
1093 }