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[deliverable/linux.git] / net / mac80211 / mesh_hwmp.c
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 <linux/etherdevice.h>
12 #include <asm/unaligned.h>
13 #include "wme.h"
14 #include "mesh.h"
15
16 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG
17 #define mhwmp_dbg(fmt, args...) \
18 printk(KERN_DEBUG "Mesh HWMP (%s): " fmt "\n", sdata->name, ##args)
19 #else
20 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0)
21 #endif
22
23 #define TEST_FRAME_LEN 8192
24 #define MAX_METRIC 0xffffffff
25 #define ARITH_SHIFT 8
26
27 /* Number of frames buffered per destination for unresolved destinations */
28 #define MESH_FRAME_QUEUE_LEN 10
29 #define MAX_PREQ_QUEUE_LEN 64
30
31 /* Destination only */
32 #define MP_F_DO 0x1
33 /* Reply and forward */
34 #define MP_F_RF 0x2
35 /* Unknown Sequence Number */
36 #define MP_F_USN 0x01
37 /* Reason code Present */
38 #define MP_F_RCODE 0x02
39
40 static void mesh_queue_preq(struct mesh_path *, u8);
41
42 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
43 {
44 if (ae)
45 offset += 6;
46 return get_unaligned_le32(preq_elem + offset);
47 }
48
49 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
50 {
51 if (ae)
52 offset += 6;
53 return get_unaligned_le16(preq_elem + offset);
54 }
55
56 /* HWMP IE processing macros */
57 #define AE_F (1<<6)
58 #define AE_F_SET(x) (*x & AE_F)
59 #define PREQ_IE_FLAGS(x) (*(x))
60 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
61 #define PREQ_IE_TTL(x) (*(x + 2))
62 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
63 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
64 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
65 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
66 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
67 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
68 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
69 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
70
71
72 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
73 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
74 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
75 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
76 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
77 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
78 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
79 #define PREP_IE_TARGET_ADDR(x) (x + 3)
80 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
81
82 #define PERR_IE_TTL(x) (*(x))
83 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
84 #define PERR_IE_TARGET_ADDR(x) (x + 3)
85 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
86 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
87
88 #define MSEC_TO_TU(x) (x*1000/1024)
89 #define SN_GT(x, y) ((s32)(y - x) < 0)
90 #define SN_LT(x, y) ((s32)(x - y) < 0)
91
92 #define net_traversal_jiffies(s) \
93 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
94 #define default_lifetime(s) \
95 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
96 #define min_preq_int_jiff(s) \
97 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
98 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
99 #define disc_timeout_jiff(s) \
100 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
101
102 enum mpath_frame_type {
103 MPATH_PREQ = 0,
104 MPATH_PREP,
105 MPATH_PERR,
106 MPATH_RANN
107 };
108
109 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
110
111 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
112 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target,
113 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl,
114 __le32 lifetime, __le32 metric, __le32 preq_id,
115 struct ieee80211_sub_if_data *sdata)
116 {
117 struct ieee80211_local *local = sdata->local;
118 struct sk_buff *skb;
119 struct ieee80211_mgmt *mgmt;
120 u8 *pos, ie_len;
121 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
122 sizeof(mgmt->u.action.u.mesh_action);
123
124 skb = dev_alloc_skb(local->tx_headroom +
125 hdr_len +
126 2 + 37); /* max HWMP IE */
127 if (!skb)
128 return -1;
129 skb_reserve(skb, local->tx_headroom);
130 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
131 memset(mgmt, 0, hdr_len);
132 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
133 IEEE80211_STYPE_ACTION);
134
135 memcpy(mgmt->da, da, ETH_ALEN);
136 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
137 /* BSSID == SA */
138 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
139 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
140 mgmt->u.action.u.mesh_action.action_code =
141 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
142
143 switch (action) {
144 case MPATH_PREQ:
145 mhwmp_dbg("sending PREQ to %pM", target);
146 ie_len = 37;
147 pos = skb_put(skb, 2 + ie_len);
148 *pos++ = WLAN_EID_PREQ;
149 break;
150 case MPATH_PREP:
151 mhwmp_dbg("sending PREP to %pM", target);
152 ie_len = 31;
153 pos = skb_put(skb, 2 + ie_len);
154 *pos++ = WLAN_EID_PREP;
155 break;
156 case MPATH_RANN:
157 mhwmp_dbg("sending RANN from %pM", orig_addr);
158 ie_len = sizeof(struct ieee80211_rann_ie);
159 pos = skb_put(skb, 2 + ie_len);
160 *pos++ = WLAN_EID_RANN;
161 break;
162 default:
163 kfree_skb(skb);
164 return -ENOTSUPP;
165 break;
166 }
167 *pos++ = ie_len;
168 *pos++ = flags;
169 *pos++ = hop_count;
170 *pos++ = ttl;
171 if (action == MPATH_PREP) {
172 memcpy(pos, target, ETH_ALEN);
173 pos += ETH_ALEN;
174 memcpy(pos, &target_sn, 4);
175 pos += 4;
176 } else {
177 if (action == MPATH_PREQ) {
178 memcpy(pos, &preq_id, 4);
179 pos += 4;
180 }
181 memcpy(pos, orig_addr, ETH_ALEN);
182 pos += ETH_ALEN;
183 memcpy(pos, &orig_sn, 4);
184 pos += 4;
185 }
186 memcpy(pos, &lifetime, 4); /* interval for RANN */
187 pos += 4;
188 memcpy(pos, &metric, 4);
189 pos += 4;
190 if (action == MPATH_PREQ) {
191 *pos++ = 1; /* destination count */
192 *pos++ = target_flags;
193 memcpy(pos, target, ETH_ALEN);
194 pos += ETH_ALEN;
195 memcpy(pos, &target_sn, 4);
196 pos += 4;
197 } else if (action == MPATH_PREP) {
198 memcpy(pos, orig_addr, ETH_ALEN);
199 pos += ETH_ALEN;
200 memcpy(pos, &orig_sn, 4);
201 pos += 4;
202 }
203
204 ieee80211_tx_skb(sdata, skb);
205 return 0;
206 }
207
208
209 /* Headroom is not adjusted. Caller should ensure that skb has sufficient
210 * headroom in case the frame is encrypted. */
211 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
212 struct sk_buff *skb)
213 {
214 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
215
216 skb_set_mac_header(skb, 0);
217 skb_set_network_header(skb, 0);
218 skb_set_transport_header(skb, 0);
219
220 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
221 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
222 skb->priority = 7;
223
224 info->control.vif = &sdata->vif;
225 ieee80211_set_qos_hdr(sdata, skb);
226 }
227
228 /**
229 * mesh_send_path error - Sends a PERR mesh management frame
230 *
231 * @target: broken destination
232 * @target_sn: SN of the broken destination
233 * @target_rcode: reason code for this PERR
234 * @ra: node this frame is addressed to
235 *
236 * Note: This function may be called with driver locks taken that the driver
237 * also acquires in the TX path. To avoid a deadlock we don't transmit the
238 * frame directly but add it to the pending queue instead.
239 */
240 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
241 __le16 target_rcode, const u8 *ra,
242 struct ieee80211_sub_if_data *sdata)
243 {
244 struct ieee80211_local *local = sdata->local;
245 struct sk_buff *skb;
246 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
247 struct ieee80211_mgmt *mgmt;
248 u8 *pos, ie_len;
249 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
250 sizeof(mgmt->u.action.u.mesh_action);
251
252 if (time_before(jiffies, ifmsh->next_perr))
253 return -EAGAIN;
254
255 skb = dev_alloc_skb(local->tx_headroom +
256 hdr_len +
257 2 + 15 /* PERR IE */);
258 if (!skb)
259 return -1;
260 skb_reserve(skb, local->tx_headroom);
261 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
262 memset(mgmt, 0, hdr_len);
263 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
264 IEEE80211_STYPE_ACTION);
265
266 memcpy(mgmt->da, ra, ETH_ALEN);
267 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
268 /* BSSID == SA */
269 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
270 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
271 mgmt->u.action.u.mesh_action.action_code =
272 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
273 ie_len = 15;
274 pos = skb_put(skb, 2 + ie_len);
275 *pos++ = WLAN_EID_PERR;
276 *pos++ = ie_len;
277 /* ttl */
278 *pos++ = ttl;
279 /* number of destinations */
280 *pos++ = 1;
281 /*
282 * flags bit, bit 1 is unset if we know the sequence number and
283 * bit 2 is set if we have a reason code
284 */
285 *pos = 0;
286 if (!target_sn)
287 *pos |= MP_F_USN;
288 if (target_rcode)
289 *pos |= MP_F_RCODE;
290 pos++;
291 memcpy(pos, target, ETH_ALEN);
292 pos += ETH_ALEN;
293 memcpy(pos, &target_sn, 4);
294 pos += 4;
295 memcpy(pos, &target_rcode, 2);
296
297 /* see note in function header */
298 prepare_frame_for_deferred_tx(sdata, skb);
299 ifmsh->next_perr = TU_TO_EXP_TIME(
300 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
301 ieee80211_add_pending_skb(local, skb);
302 return 0;
303 }
304
305 void ieee80211s_update_metric(struct ieee80211_local *local,
306 struct sta_info *stainfo, struct sk_buff *skb)
307 {
308 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
309 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
310 int failed;
311
312 if (!ieee80211_is_data(hdr->frame_control))
313 return;
314
315 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
316
317 /* moving average, scaled to 100 */
318 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
319 if (stainfo->fail_avg > 95)
320 mesh_plink_broken(stainfo);
321 }
322
323 static u32 airtime_link_metric_get(struct ieee80211_local *local,
324 struct sta_info *sta)
325 {
326 struct ieee80211_supported_band *sband;
327 struct rate_info rinfo;
328 /* This should be adjusted for each device */
329 int device_constant = 1 << ARITH_SHIFT;
330 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
331 int s_unit = 1 << ARITH_SHIFT;
332 int rate, err;
333 u32 tx_time, estimated_retx;
334 u64 result;
335
336 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
337
338 if (sta->fail_avg >= 100)
339 return MAX_METRIC;
340
341 sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo);
342 rate = cfg80211_calculate_bitrate(&rinfo);
343 if (WARN_ON(!rate))
344 return MAX_METRIC;
345
346 err = (sta->fail_avg << ARITH_SHIFT) / 100;
347
348 /* bitrate is in units of 100 Kbps, while we need rate in units of
349 * 1Mbps. This will be corrected on tx_time computation.
350 */
351 tx_time = (device_constant + 10 * test_frame_len / rate);
352 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
353 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
354 return (u32)result;
355 }
356
357 /**
358 * hwmp_route_info_get - Update routing info to originator and transmitter
359 *
360 * @sdata: local mesh subif
361 * @mgmt: mesh management frame
362 * @hwmp_ie: hwmp information element (PREP or PREQ)
363 *
364 * This function updates the path routing information to the originator and the
365 * transmitter of a HWMP PREQ or PREP frame.
366 *
367 * Returns: metric to frame originator or 0 if the frame should not be further
368 * processed
369 *
370 * Notes: this function is the only place (besides user-provided info) where
371 * path routing information is updated.
372 */
373 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
374 struct ieee80211_mgmt *mgmt,
375 u8 *hwmp_ie, enum mpath_frame_type action)
376 {
377 struct ieee80211_local *local = sdata->local;
378 struct mesh_path *mpath;
379 struct sta_info *sta;
380 bool fresh_info;
381 u8 *orig_addr, *ta;
382 u32 orig_sn, orig_metric;
383 unsigned long orig_lifetime, exp_time;
384 u32 last_hop_metric, new_metric;
385 bool process = true;
386
387 rcu_read_lock();
388 sta = sta_info_get(sdata, mgmt->sa);
389 if (!sta) {
390 rcu_read_unlock();
391 return 0;
392 }
393
394 last_hop_metric = airtime_link_metric_get(local, sta);
395 /* Update and check originator routing info */
396 fresh_info = true;
397
398 switch (action) {
399 case MPATH_PREQ:
400 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
401 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
402 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
403 orig_metric = PREQ_IE_METRIC(hwmp_ie);
404 break;
405 case MPATH_PREP:
406 /* Originator here refers to the MP that was the target in the
407 * Path Request. We divert from the nomenclature in the draft
408 * so that we can easily use a single function to gather path
409 * information from both PREQ and PREP frames.
410 */
411 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
412 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
413 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
414 orig_metric = PREP_IE_METRIC(hwmp_ie);
415 break;
416 default:
417 rcu_read_unlock();
418 return 0;
419 }
420 new_metric = orig_metric + last_hop_metric;
421 if (new_metric < orig_metric)
422 new_metric = MAX_METRIC;
423 exp_time = TU_TO_EXP_TIME(orig_lifetime);
424
425 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0) {
426 /* This MP is the originator, we are not interested in this
427 * frame, except for updating transmitter's path info.
428 */
429 process = false;
430 fresh_info = false;
431 } else {
432 mpath = mesh_path_lookup(orig_addr, sdata);
433 if (mpath) {
434 spin_lock_bh(&mpath->state_lock);
435 if (mpath->flags & MESH_PATH_FIXED)
436 fresh_info = false;
437 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
438 (mpath->flags & MESH_PATH_SN_VALID)) {
439 if (SN_GT(mpath->sn, orig_sn) ||
440 (mpath->sn == orig_sn &&
441 new_metric >= mpath->metric)) {
442 process = false;
443 fresh_info = false;
444 }
445 }
446 } else {
447 mesh_path_add(orig_addr, sdata);
448 mpath = mesh_path_lookup(orig_addr, sdata);
449 if (!mpath) {
450 rcu_read_unlock();
451 return 0;
452 }
453 spin_lock_bh(&mpath->state_lock);
454 }
455
456 if (fresh_info) {
457 mesh_path_assign_nexthop(mpath, sta);
458 mpath->flags |= MESH_PATH_SN_VALID;
459 mpath->metric = new_metric;
460 mpath->sn = orig_sn;
461 mpath->exp_time = time_after(mpath->exp_time, exp_time)
462 ? mpath->exp_time : exp_time;
463 mesh_path_activate(mpath);
464 spin_unlock_bh(&mpath->state_lock);
465 mesh_path_tx_pending(mpath);
466 /* draft says preq_id should be saved to, but there does
467 * not seem to be any use for it, skipping by now
468 */
469 } else
470 spin_unlock_bh(&mpath->state_lock);
471 }
472
473 /* Update and check transmitter routing info */
474 ta = mgmt->sa;
475 if (compare_ether_addr(orig_addr, ta) == 0)
476 fresh_info = false;
477 else {
478 fresh_info = true;
479
480 mpath = mesh_path_lookup(ta, sdata);
481 if (mpath) {
482 spin_lock_bh(&mpath->state_lock);
483 if ((mpath->flags & MESH_PATH_FIXED) ||
484 ((mpath->flags & MESH_PATH_ACTIVE) &&
485 (last_hop_metric > mpath->metric)))
486 fresh_info = false;
487 } else {
488 mesh_path_add(ta, sdata);
489 mpath = mesh_path_lookup(ta, sdata);
490 if (!mpath) {
491 rcu_read_unlock();
492 return 0;
493 }
494 spin_lock_bh(&mpath->state_lock);
495 }
496
497 if (fresh_info) {
498 mesh_path_assign_nexthop(mpath, sta);
499 mpath->metric = last_hop_metric;
500 mpath->exp_time = time_after(mpath->exp_time, exp_time)
501 ? mpath->exp_time : exp_time;
502 mesh_path_activate(mpath);
503 spin_unlock_bh(&mpath->state_lock);
504 mesh_path_tx_pending(mpath);
505 } else
506 spin_unlock_bh(&mpath->state_lock);
507 }
508
509 rcu_read_unlock();
510
511 return process ? new_metric : 0;
512 }
513
514 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
515 struct ieee80211_mgmt *mgmt,
516 u8 *preq_elem, u32 metric)
517 {
518 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
519 struct mesh_path *mpath = NULL;
520 u8 *target_addr, *orig_addr;
521 const u8 *da;
522 u8 target_flags, ttl;
523 u32 orig_sn, target_sn, lifetime;
524 bool reply = false;
525 bool forward = true;
526
527 /* Update target SN, if present */
528 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
529 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
530 target_sn = PREQ_IE_TARGET_SN(preq_elem);
531 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
532 target_flags = PREQ_IE_TARGET_F(preq_elem);
533
534 mhwmp_dbg("received PREQ from %pM", orig_addr);
535
536 if (compare_ether_addr(target_addr, sdata->vif.addr) == 0) {
537 mhwmp_dbg("PREQ is for us");
538 forward = false;
539 reply = true;
540 metric = 0;
541 if (time_after(jiffies, ifmsh->last_sn_update +
542 net_traversal_jiffies(sdata)) ||
543 time_before(jiffies, ifmsh->last_sn_update)) {
544 target_sn = ++ifmsh->sn;
545 ifmsh->last_sn_update = jiffies;
546 }
547 } else {
548 rcu_read_lock();
549 mpath = mesh_path_lookup(target_addr, sdata);
550 if (mpath) {
551 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
552 SN_LT(mpath->sn, target_sn)) {
553 mpath->sn = target_sn;
554 mpath->flags |= MESH_PATH_SN_VALID;
555 } else if ((!(target_flags & MP_F_DO)) &&
556 (mpath->flags & MESH_PATH_ACTIVE)) {
557 reply = true;
558 metric = mpath->metric;
559 target_sn = mpath->sn;
560 if (target_flags & MP_F_RF)
561 target_flags |= MP_F_DO;
562 else
563 forward = false;
564 }
565 }
566 rcu_read_unlock();
567 }
568
569 if (reply) {
570 lifetime = PREQ_IE_LIFETIME(preq_elem);
571 ttl = ifmsh->mshcfg.element_ttl;
572 if (ttl != 0) {
573 mhwmp_dbg("replying to the PREQ");
574 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
575 cpu_to_le32(orig_sn), 0, target_addr,
576 cpu_to_le32(target_sn), mgmt->sa, 0, ttl,
577 cpu_to_le32(lifetime), cpu_to_le32(metric),
578 0, sdata);
579 } else
580 ifmsh->mshstats.dropped_frames_ttl++;
581 }
582
583 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
584 u32 preq_id;
585 u8 hopcount, flags;
586
587 ttl = PREQ_IE_TTL(preq_elem);
588 lifetime = PREQ_IE_LIFETIME(preq_elem);
589 if (ttl <= 1) {
590 ifmsh->mshstats.dropped_frames_ttl++;
591 return;
592 }
593 mhwmp_dbg("forwarding the PREQ from %pM", orig_addr);
594 --ttl;
595 flags = PREQ_IE_FLAGS(preq_elem);
596 preq_id = PREQ_IE_PREQ_ID(preq_elem);
597 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
598 da = (mpath && mpath->is_root) ?
599 mpath->rann_snd_addr : broadcast_addr;
600 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
601 cpu_to_le32(orig_sn), target_flags, target_addr,
602 cpu_to_le32(target_sn), da,
603 hopcount, ttl, cpu_to_le32(lifetime),
604 cpu_to_le32(metric), cpu_to_le32(preq_id),
605 sdata);
606 ifmsh->mshstats.fwded_mcast++;
607 ifmsh->mshstats.fwded_frames++;
608 }
609 }
610
611
612 static inline struct sta_info *
613 next_hop_deref_protected(struct mesh_path *mpath)
614 {
615 return rcu_dereference_protected(mpath->next_hop,
616 lockdep_is_held(&mpath->state_lock));
617 }
618
619
620 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
621 struct ieee80211_mgmt *mgmt,
622 u8 *prep_elem, u32 metric)
623 {
624 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
625 struct mesh_path *mpath;
626 u8 *target_addr, *orig_addr;
627 u8 ttl, hopcount, flags;
628 u8 next_hop[ETH_ALEN];
629 u32 target_sn, orig_sn, lifetime;
630
631 mhwmp_dbg("received PREP from %pM", PREP_IE_ORIG_ADDR(prep_elem));
632
633 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
634 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0)
635 /* destination, no forwarding required */
636 return;
637
638 if (!ifmsh->mshcfg.dot11MeshForwarding)
639 return;
640
641 ttl = PREP_IE_TTL(prep_elem);
642 if (ttl <= 1) {
643 sdata->u.mesh.mshstats.dropped_frames_ttl++;
644 return;
645 }
646
647 rcu_read_lock();
648 mpath = mesh_path_lookup(orig_addr, sdata);
649 if (mpath)
650 spin_lock_bh(&mpath->state_lock);
651 else
652 goto fail;
653 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
654 spin_unlock_bh(&mpath->state_lock);
655 goto fail;
656 }
657 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
658 spin_unlock_bh(&mpath->state_lock);
659 --ttl;
660 flags = PREP_IE_FLAGS(prep_elem);
661 lifetime = PREP_IE_LIFETIME(prep_elem);
662 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
663 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
664 target_sn = PREP_IE_TARGET_SN(prep_elem);
665 orig_sn = PREP_IE_ORIG_SN(prep_elem);
666
667 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
668 cpu_to_le32(orig_sn), 0, target_addr,
669 cpu_to_le32(target_sn), next_hop, hopcount,
670 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
671 0, sdata);
672 rcu_read_unlock();
673
674 sdata->u.mesh.mshstats.fwded_unicast++;
675 sdata->u.mesh.mshstats.fwded_frames++;
676 return;
677
678 fail:
679 rcu_read_unlock();
680 sdata->u.mesh.mshstats.dropped_frames_no_route++;
681 }
682
683 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
684 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
685 {
686 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
687 struct mesh_path *mpath;
688 u8 ttl;
689 u8 *ta, *target_addr;
690 u32 target_sn;
691 u16 target_rcode;
692
693 ta = mgmt->sa;
694 ttl = PERR_IE_TTL(perr_elem);
695 if (ttl <= 1) {
696 ifmsh->mshstats.dropped_frames_ttl++;
697 return;
698 }
699 ttl--;
700 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
701 target_sn = PERR_IE_TARGET_SN(perr_elem);
702 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
703
704 rcu_read_lock();
705 mpath = mesh_path_lookup(target_addr, sdata);
706 if (mpath) {
707 struct sta_info *sta;
708
709 spin_lock_bh(&mpath->state_lock);
710 sta = next_hop_deref_protected(mpath);
711 if (mpath->flags & MESH_PATH_ACTIVE &&
712 compare_ether_addr(ta, sta->sta.addr) == 0 &&
713 (!(mpath->flags & MESH_PATH_SN_VALID) ||
714 SN_GT(target_sn, mpath->sn))) {
715 mpath->flags &= ~MESH_PATH_ACTIVE;
716 mpath->sn = target_sn;
717 spin_unlock_bh(&mpath->state_lock);
718 if (!ifmsh->mshcfg.dot11MeshForwarding)
719 goto endperr;
720 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
721 cpu_to_le16(target_rcode),
722 broadcast_addr, sdata);
723 } else
724 spin_unlock_bh(&mpath->state_lock);
725 }
726 endperr:
727 rcu_read_unlock();
728 }
729
730 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
731 struct ieee80211_mgmt *mgmt,
732 struct ieee80211_rann_ie *rann)
733 {
734 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
735 struct ieee80211_local *local = sdata->local;
736 struct sta_info *sta;
737 struct mesh_path *mpath;
738 u8 ttl, flags, hopcount;
739 u8 *orig_addr;
740 u32 orig_sn, metric, metric_txsta, interval;
741 bool root_is_gate;
742
743 ttl = rann->rann_ttl;
744 if (ttl <= 1) {
745 ifmsh->mshstats.dropped_frames_ttl++;
746 return;
747 }
748 ttl--;
749 flags = rann->rann_flags;
750 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
751 orig_addr = rann->rann_addr;
752 orig_sn = le32_to_cpu(rann->rann_seq);
753 interval = le32_to_cpu(rann->rann_interval);
754 hopcount = rann->rann_hopcount;
755 hopcount++;
756 metric = le32_to_cpu(rann->rann_metric);
757
758 /* Ignore our own RANNs */
759 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0)
760 return;
761
762 mhwmp_dbg("received RANN from %pM via neighbour %pM (is_gate=%d)",
763 orig_addr, mgmt->sa, root_is_gate);
764
765 rcu_read_lock();
766 sta = sta_info_get(sdata, mgmt->sa);
767 if (!sta) {
768 rcu_read_unlock();
769 return;
770 }
771
772 metric_txsta = airtime_link_metric_get(local, sta);
773
774 mpath = mesh_path_lookup(orig_addr, sdata);
775 if (!mpath) {
776 mesh_path_add(orig_addr, sdata);
777 mpath = mesh_path_lookup(orig_addr, sdata);
778 if (!mpath) {
779 rcu_read_unlock();
780 sdata->u.mesh.mshstats.dropped_frames_no_route++;
781 return;
782 }
783 }
784
785 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
786 time_after(jiffies, mpath->exp_time - 1*HZ)) &&
787 !(mpath->flags & MESH_PATH_FIXED)) {
788 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
789 orig_addr);
790 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
791 }
792
793 if ((SN_LT(mpath->sn, orig_sn) || (mpath->sn == orig_sn &&
794 metric < mpath->rann_metric)) && ifmsh->mshcfg.dot11MeshForwarding) {
795 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
796 cpu_to_le32(orig_sn),
797 0, NULL, 0, broadcast_addr,
798 hopcount, ttl, cpu_to_le32(interval),
799 cpu_to_le32(metric + metric_txsta),
800 0, sdata);
801 mpath->sn = orig_sn;
802 mpath->rann_metric = metric + metric_txsta;
803 }
804
805 /* Using individually addressed PREQ for root node */
806 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
807 mpath->is_root = true;
808
809 if (root_is_gate)
810 mesh_path_add_gate(mpath);
811
812 rcu_read_unlock();
813 }
814
815
816 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
817 struct ieee80211_mgmt *mgmt,
818 size_t len)
819 {
820 struct ieee802_11_elems elems;
821 size_t baselen;
822 u32 last_hop_metric;
823 struct sta_info *sta;
824
825 /* need action_code */
826 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
827 return;
828
829 rcu_read_lock();
830 sta = sta_info_get(sdata, mgmt->sa);
831 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) {
832 rcu_read_unlock();
833 return;
834 }
835 rcu_read_unlock();
836
837 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
838 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
839 len - baselen, &elems);
840
841 if (elems.preq) {
842 if (elems.preq_len != 37)
843 /* Right now we support just 1 destination and no AE */
844 return;
845 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
846 MPATH_PREQ);
847 if (last_hop_metric)
848 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
849 last_hop_metric);
850 }
851 if (elems.prep) {
852 if (elems.prep_len != 31)
853 /* Right now we support no AE */
854 return;
855 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
856 MPATH_PREP);
857 if (last_hop_metric)
858 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
859 last_hop_metric);
860 }
861 if (elems.perr) {
862 if (elems.perr_len != 15)
863 /* Right now we support only one destination per PERR */
864 return;
865 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
866 }
867 if (elems.rann)
868 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
869 }
870
871 /**
872 * mesh_queue_preq - queue a PREQ to a given destination
873 *
874 * @mpath: mesh path to discover
875 * @flags: special attributes of the PREQ to be sent
876 *
877 * Locking: the function must be called from within a rcu read lock block.
878 *
879 */
880 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
881 {
882 struct ieee80211_sub_if_data *sdata = mpath->sdata;
883 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
884 struct mesh_preq_queue *preq_node;
885
886 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
887 if (!preq_node) {
888 mhwmp_dbg("could not allocate PREQ node");
889 return;
890 }
891
892 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
893 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
894 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
895 kfree(preq_node);
896 if (printk_ratelimit())
897 mhwmp_dbg("PREQ node queue full");
898 return;
899 }
900
901 spin_lock(&mpath->state_lock);
902 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
903 spin_unlock(&mpath->state_lock);
904 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
905 kfree(preq_node);
906 return;
907 }
908
909 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
910 preq_node->flags = flags;
911
912 mpath->flags |= MESH_PATH_REQ_QUEUED;
913 spin_unlock(&mpath->state_lock);
914
915 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
916 ++ifmsh->preq_queue_len;
917 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
918
919 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
920 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
921
922 else if (time_before(jiffies, ifmsh->last_preq)) {
923 /* avoid long wait if did not send preqs for a long time
924 * and jiffies wrapped around
925 */
926 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
927 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
928 } else
929 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
930 min_preq_int_jiff(sdata));
931 }
932
933 /**
934 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
935 *
936 * @sdata: local mesh subif
937 */
938 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
939 {
940 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
941 struct mesh_preq_queue *preq_node;
942 struct mesh_path *mpath;
943 u8 ttl, target_flags;
944 const u8 *da;
945 u32 lifetime;
946
947 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
948 if (!ifmsh->preq_queue_len ||
949 time_before(jiffies, ifmsh->last_preq +
950 min_preq_int_jiff(sdata))) {
951 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
952 return;
953 }
954
955 preq_node = list_first_entry(&ifmsh->preq_queue.list,
956 struct mesh_preq_queue, list);
957 list_del(&preq_node->list);
958 --ifmsh->preq_queue_len;
959 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
960
961 rcu_read_lock();
962 mpath = mesh_path_lookup(preq_node->dst, sdata);
963 if (!mpath)
964 goto enddiscovery;
965
966 spin_lock_bh(&mpath->state_lock);
967 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
968 if (preq_node->flags & PREQ_Q_F_START) {
969 if (mpath->flags & MESH_PATH_RESOLVING) {
970 spin_unlock_bh(&mpath->state_lock);
971 goto enddiscovery;
972 } else {
973 mpath->flags &= ~MESH_PATH_RESOLVED;
974 mpath->flags |= MESH_PATH_RESOLVING;
975 mpath->discovery_retries = 0;
976 mpath->discovery_timeout = disc_timeout_jiff(sdata);
977 }
978 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
979 mpath->flags & MESH_PATH_RESOLVED) {
980 mpath->flags &= ~MESH_PATH_RESOLVING;
981 spin_unlock_bh(&mpath->state_lock);
982 goto enddiscovery;
983 }
984
985 ifmsh->last_preq = jiffies;
986
987 if (time_after(jiffies, ifmsh->last_sn_update +
988 net_traversal_jiffies(sdata)) ||
989 time_before(jiffies, ifmsh->last_sn_update)) {
990 ++ifmsh->sn;
991 sdata->u.mesh.last_sn_update = jiffies;
992 }
993 lifetime = default_lifetime(sdata);
994 ttl = sdata->u.mesh.mshcfg.element_ttl;
995 if (ttl == 0) {
996 sdata->u.mesh.mshstats.dropped_frames_ttl++;
997 spin_unlock_bh(&mpath->state_lock);
998 goto enddiscovery;
999 }
1000
1001 if (preq_node->flags & PREQ_Q_F_REFRESH)
1002 target_flags = MP_F_DO;
1003 else
1004 target_flags = MP_F_RF;
1005
1006 spin_unlock_bh(&mpath->state_lock);
1007 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1008 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
1009 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
1010 cpu_to_le32(mpath->sn), da, 0,
1011 ttl, cpu_to_le32(lifetime), 0,
1012 cpu_to_le32(ifmsh->preq_id++), sdata);
1013 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1014
1015 enddiscovery:
1016 rcu_read_unlock();
1017 kfree(preq_node);
1018 }
1019
1020 /* mesh_nexthop_resolve - lookup next hop for given skb and start path
1021 * discovery if no forwarding information is found.
1022 *
1023 * @skb: 802.11 frame to be sent
1024 * @sdata: network subif the frame will be sent through
1025 *
1026 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1027 * skb is freeed here if no mpath could be allocated.
1028 */
1029 int mesh_nexthop_resolve(struct sk_buff *skb,
1030 struct ieee80211_sub_if_data *sdata)
1031 {
1032 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1033 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1034 struct mesh_path *mpath;
1035 struct sk_buff *skb_to_free = NULL;
1036 u8 *target_addr = hdr->addr3;
1037 int err = 0;
1038
1039 rcu_read_lock();
1040 err = mesh_nexthop_lookup(skb, sdata);
1041 if (!err)
1042 goto endlookup;
1043
1044 /* no nexthop found, start resolving */
1045 mpath = mesh_path_lookup(target_addr, sdata);
1046 if (!mpath) {
1047 mesh_path_add(target_addr, sdata);
1048 mpath = mesh_path_lookup(target_addr, sdata);
1049 if (!mpath) {
1050 mesh_path_discard_frame(skb, sdata);
1051 err = -ENOSPC;
1052 goto endlookup;
1053 }
1054 }
1055
1056 if (!(mpath->flags & MESH_PATH_RESOLVING))
1057 mesh_queue_preq(mpath, PREQ_Q_F_START);
1058
1059 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1060 skb_to_free = skb_dequeue(&mpath->frame_queue);
1061
1062 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1063 ieee80211_set_qos_hdr(sdata, skb);
1064 skb_queue_tail(&mpath->frame_queue, skb);
1065 err = -ENOENT;
1066 if (skb_to_free)
1067 mesh_path_discard_frame(skb_to_free, sdata);
1068
1069 endlookup:
1070 rcu_read_unlock();
1071 return err;
1072 }
1073 /**
1074 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1075 * this function is considered "using" the associated mpath, so preempt a path
1076 * refresh if this mpath expires soon.
1077 *
1078 * @skb: 802.11 frame to be sent
1079 * @sdata: network subif the frame will be sent through
1080 *
1081 * Returns: 0 if the next hop was found. Nonzero otherwise.
1082 */
1083 int mesh_nexthop_lookup(struct sk_buff *skb,
1084 struct ieee80211_sub_if_data *sdata)
1085 {
1086 struct mesh_path *mpath;
1087 struct sta_info *next_hop;
1088 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1089 u8 *target_addr = hdr->addr3;
1090 int err = -ENOENT;
1091
1092 rcu_read_lock();
1093 mpath = mesh_path_lookup(target_addr, sdata);
1094
1095 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1096 goto endlookup;
1097
1098 if (time_after(jiffies,
1099 mpath->exp_time -
1100 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1101 !compare_ether_addr(sdata->vif.addr, hdr->addr4) &&
1102 !(mpath->flags & MESH_PATH_RESOLVING) &&
1103 !(mpath->flags & MESH_PATH_FIXED))
1104 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1105
1106 next_hop = rcu_dereference(mpath->next_hop);
1107 if (next_hop) {
1108 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1109 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1110 err = 0;
1111 }
1112
1113 endlookup:
1114 rcu_read_unlock();
1115 return err;
1116 }
1117
1118 void mesh_path_timer(unsigned long data)
1119 {
1120 struct mesh_path *mpath = (void *) data;
1121 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1122 int ret;
1123
1124 if (sdata->local->quiescing)
1125 return;
1126
1127 spin_lock_bh(&mpath->state_lock);
1128 if (mpath->flags & MESH_PATH_RESOLVED ||
1129 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1130 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1131 spin_unlock_bh(&mpath->state_lock);
1132 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1133 ++mpath->discovery_retries;
1134 mpath->discovery_timeout *= 2;
1135 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1136 spin_unlock_bh(&mpath->state_lock);
1137 mesh_queue_preq(mpath, 0);
1138 } else {
1139 mpath->flags = 0;
1140 mpath->exp_time = jiffies;
1141 spin_unlock_bh(&mpath->state_lock);
1142 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1143 ret = mesh_path_send_to_gates(mpath);
1144 if (ret)
1145 mhwmp_dbg("no gate was reachable");
1146 } else
1147 mesh_path_flush_pending(mpath);
1148 }
1149 }
1150
1151 void
1152 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1153 {
1154 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1155 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1156 u8 flags;
1157
1158 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1159 ? RANN_FLAG_IS_GATE : 0;
1160 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1161 cpu_to_le32(++ifmsh->sn),
1162 0, NULL, 0, broadcast_addr,
1163 0, sdata->u.mesh.mshcfg.element_ttl,
1164 cpu_to_le32(interval), 0, 0, sdata);
1165 }
Linux kernel - Deliverables
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