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 #define TEST_FRAME_LEN 8192
17 #define MAX_METRIC 0xffffffff
18 #define ARITH_SHIFT 8
19
20 #define MAX_PREQ_QUEUE_LEN 64
21
22 /* Destination only */
23 #define MP_F_DO 0x1
24 /* Reply and forward */
25 #define MP_F_RF 0x2
26 /* Unknown Sequence Number */
27 #define MP_F_USN 0x01
28 /* Reason code Present */
29 #define MP_F_RCODE 0x02
30
31 static void mesh_queue_preq(struct mesh_path *, u8);
32
u32_field_get(const u8 * preq_elem,int offset,bool ae)33 static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae)
34 {
35 if (ae)
36 offset += 6;
37 return get_unaligned_le32(preq_elem + offset);
38 }
39
u16_field_get(const u8 * preq_elem,int offset,bool ae)40 static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae)
41 {
42 if (ae)
43 offset += 6;
44 return get_unaligned_le16(preq_elem + offset);
45 }
46
47 /* HWMP IE processing macros */
48 #define AE_F (1<<6)
49 #define AE_F_SET(x) (*x & AE_F)
50 #define PREQ_IE_FLAGS(x) (*(x))
51 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
52 #define PREQ_IE_TTL(x) (*(x + 2))
53 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
54 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
55 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0)
56 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x))
57 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x))
58 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
59 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
60 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x))
61
62
63 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
64 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
65 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
66 #define PREP_IE_ORIG_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
67 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
68 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x))
69 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x))
70 #define PREP_IE_TARGET_ADDR(x) (x + 3)
71 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
72
73 #define PERR_IE_TTL(x) (*(x))
74 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
75 #define PERR_IE_TARGET_ADDR(x) (x + 3)
76 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
77 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
78
79 #define MSEC_TO_TU(x) (x*1000/1024)
80 #define SN_GT(x, y) ((s32)(y - x) < 0)
81 #define SN_LT(x, y) ((s32)(x - y) < 0)
82
83 #define net_traversal_jiffies(s) \
84 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
85 #define default_lifetime(s) \
86 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
87 #define min_preq_int_jiff(s) \
88 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
89 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
90 #define disc_timeout_jiff(s) \
91 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
92 #define root_path_confirmation_jiffies(s) \
93 msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
94
95 enum mpath_frame_type {
96 MPATH_PREQ = 0,
97 MPATH_PREP,
98 MPATH_PERR,
99 MPATH_RANN
100 };
101
102 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
103
mesh_path_sel_frame_tx(enum mpath_frame_type action,u8 flags,const u8 * orig_addr,u32 orig_sn,u8 target_flags,const u8 * target,u32 target_sn,const u8 * da,u8 hop_count,u8 ttl,u32 lifetime,u32 metric,u32 preq_id,struct ieee80211_sub_if_data * sdata)104 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
105 const u8 *orig_addr, u32 orig_sn,
106 u8 target_flags, const u8 *target,
107 u32 target_sn, const u8 *da,
108 u8 hop_count, u8 ttl,
109 u32 lifetime, u32 metric, u32 preq_id,
110 struct ieee80211_sub_if_data *sdata)
111 {
112 struct ieee80211_local *local = sdata->local;
113 struct sk_buff *skb;
114 struct ieee80211_mgmt *mgmt;
115 u8 *pos, ie_len;
116 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
117 sizeof(mgmt->u.action.u.mesh_action);
118
119 skb = dev_alloc_skb(local->tx_headroom +
120 hdr_len +
121 2 + 37); /* max HWMP IE */
122 if (!skb)
123 return -1;
124 skb_reserve(skb, local->tx_headroom);
125 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
126 memset(mgmt, 0, hdr_len);
127 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
128 IEEE80211_STYPE_ACTION);
129
130 memcpy(mgmt->da, da, ETH_ALEN);
131 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
132 /* BSSID == SA */
133 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
134 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
135 mgmt->u.action.u.mesh_action.action_code =
136 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
137
138 switch (action) {
139 case MPATH_PREQ:
140 mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
141 ie_len = 37;
142 pos = skb_put(skb, 2 + ie_len);
143 *pos++ = WLAN_EID_PREQ;
144 break;
145 case MPATH_PREP:
146 mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr);
147 ie_len = 31;
148 pos = skb_put(skb, 2 + ie_len);
149 *pos++ = WLAN_EID_PREP;
150 break;
151 case MPATH_RANN:
152 mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
153 ie_len = sizeof(struct ieee80211_rann_ie);
154 pos = skb_put(skb, 2 + ie_len);
155 *pos++ = WLAN_EID_RANN;
156 break;
157 default:
158 kfree_skb(skb);
159 return -ENOTSUPP;
160 }
161 *pos++ = ie_len;
162 *pos++ = flags;
163 *pos++ = hop_count;
164 *pos++ = ttl;
165 if (action == MPATH_PREP) {
166 memcpy(pos, target, ETH_ALEN);
167 pos += ETH_ALEN;
168 put_unaligned_le32(target_sn, pos);
169 pos += 4;
170 } else {
171 if (action == MPATH_PREQ) {
172 put_unaligned_le32(preq_id, pos);
173 pos += 4;
174 }
175 memcpy(pos, orig_addr, ETH_ALEN);
176 pos += ETH_ALEN;
177 put_unaligned_le32(orig_sn, pos);
178 pos += 4;
179 }
180 put_unaligned_le32(lifetime, pos); /* interval for RANN */
181 pos += 4;
182 put_unaligned_le32(metric, pos);
183 pos += 4;
184 if (action == MPATH_PREQ) {
185 *pos++ = 1; /* destination count */
186 *pos++ = target_flags;
187 memcpy(pos, target, ETH_ALEN);
188 pos += ETH_ALEN;
189 put_unaligned_le32(target_sn, pos);
190 pos += 4;
191 } else if (action == MPATH_PREP) {
192 memcpy(pos, orig_addr, ETH_ALEN);
193 pos += ETH_ALEN;
194 put_unaligned_le32(orig_sn, pos);
195 pos += 4;
196 }
197
198 ieee80211_tx_skb(sdata, skb);
199 return 0;
200 }
201
202
203 /* Headroom is not adjusted. Caller should ensure that skb has sufficient
204 * headroom in case the frame is encrypted. */
prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)205 static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
206 struct sk_buff *skb)
207 {
208 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
209 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
210
211 skb_set_mac_header(skb, 0);
212 skb_set_network_header(skb, 0);
213 skb_set_transport_header(skb, 0);
214
215 /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
216 skb_set_queue_mapping(skb, IEEE80211_AC_VO);
217 skb->priority = 7;
218
219 info->control.vif = &sdata->vif;
220 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
221 ieee80211_set_qos_hdr(sdata, skb);
222 ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
223 }
224
225 /**
226 * mesh_path_error_tx - Sends a PERR mesh management frame
227 *
228 * @ttl: allowed remaining hops
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 * @sdata: local mesh subif
234 *
235 * Note: This function may be called with driver locks taken that the driver
236 * also acquires in the TX path. To avoid a deadlock we don't transmit the
237 * frame directly but add it to the pending queue instead.
238 */
mesh_path_error_tx(struct ieee80211_sub_if_data * sdata,u8 ttl,const u8 * target,u32 target_sn,u16 target_rcode,const u8 * ra)239 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
240 u8 ttl, const u8 *target, u32 target_sn,
241 u16 target_rcode, const u8 *ra)
242 {
243 struct ieee80211_local *local = sdata->local;
244 struct sk_buff *skb;
245 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
246 struct ieee80211_mgmt *mgmt;
247 u8 *pos, ie_len;
248 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
249 sizeof(mgmt->u.action.u.mesh_action);
250
251 if (time_before(jiffies, ifmsh->next_perr))
252 return -EAGAIN;
253
254 skb = dev_alloc_skb(local->tx_headroom +
255 sdata->encrypt_headroom +
256 IEEE80211_ENCRYPT_TAILROOM +
257 hdr_len +
258 2 + 15 /* PERR IE */);
259 if (!skb)
260 return -1;
261 skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom);
262 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
263 memset(mgmt, 0, hdr_len);
264 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
265 IEEE80211_STYPE_ACTION);
266
267 memcpy(mgmt->da, ra, ETH_ALEN);
268 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
269 /* BSSID == SA */
270 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
271 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
272 mgmt->u.action.u.mesh_action.action_code =
273 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
274 ie_len = 15;
275 pos = skb_put(skb, 2 + ie_len);
276 *pos++ = WLAN_EID_PERR;
277 *pos++ = ie_len;
278 /* ttl */
279 *pos++ = ttl;
280 /* number of destinations */
281 *pos++ = 1;
282 /*
283 * flags bit, bit 1 is unset if we know the sequence number and
284 * bit 2 is set if we have a reason code
285 */
286 *pos = 0;
287 if (!target_sn)
288 *pos |= MP_F_USN;
289 if (target_rcode)
290 *pos |= MP_F_RCODE;
291 pos++;
292 memcpy(pos, target, ETH_ALEN);
293 pos += ETH_ALEN;
294 put_unaligned_le32(target_sn, pos);
295 pos += 4;
296 put_unaligned_le16(target_rcode, pos);
297
298 /* see note in function header */
299 prepare_frame_for_deferred_tx(sdata, skb);
300 ifmsh->next_perr = TU_TO_EXP_TIME(
301 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
302 ieee80211_add_pending_skb(local, skb);
303 return 0;
304 }
305
ieee80211s_update_metric(struct ieee80211_local * local,struct sta_info * sta,struct sk_buff * skb)306 void ieee80211s_update_metric(struct ieee80211_local *local,
307 struct sta_info *sta, struct sk_buff *skb)
308 {
309 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
310 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
311 int failed;
312
313 if (!ieee80211_is_data(hdr->frame_control))
314 return;
315
316 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
317
318 /* moving average, scaled to 100 */
319 sta->fail_avg = ((80 * sta->fail_avg + 5) / 100 + 20 * failed);
320 if (sta->fail_avg > 95)
321 mesh_plink_broken(sta);
322 }
323
airtime_link_metric_get(struct ieee80211_local * local,struct sta_info * sta)324 static u32 airtime_link_metric_get(struct ieee80211_local *local,
325 struct sta_info *sta)
326 {
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 if (sta->fail_avg >= 100)
337 return MAX_METRIC;
338
339 sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo);
340 rate = cfg80211_calculate_bitrate(&rinfo);
341 if (WARN_ON(!rate))
342 return MAX_METRIC;
343
344 err = (sta->fail_avg << ARITH_SHIFT) / 100;
345
346 /* bitrate is in units of 100 Kbps, while we need rate in units of
347 * 1Mbps. This will be corrected on tx_time computation.
348 */
349 tx_time = (device_constant + 10 * test_frame_len / rate);
350 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
351 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
352 return (u32)result;
353 }
354
355 /**
356 * hwmp_route_info_get - Update routing info to originator and transmitter
357 *
358 * @sdata: local mesh subif
359 * @mgmt: mesh management frame
360 * @hwmp_ie: hwmp information element (PREP or PREQ)
361 * @action: type of hwmp ie
362 *
363 * This function updates the path routing information to the originator and the
364 * transmitter of a HWMP PREQ or PREP frame.
365 *
366 * Returns: metric to frame originator or 0 if the frame should not be further
367 * processed
368 *
369 * Notes: this function is the only place (besides user-provided info) where
370 * path routing information is updated.
371 */
hwmp_route_info_get(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * hwmp_ie,enum mpath_frame_type action)372 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
373 struct ieee80211_mgmt *mgmt,
374 const u8 *hwmp_ie, enum mpath_frame_type action)
375 {
376 struct ieee80211_local *local = sdata->local;
377 struct mesh_path *mpath;
378 struct sta_info *sta;
379 bool fresh_info;
380 const u8 *orig_addr, *ta;
381 u32 orig_sn, orig_metric;
382 unsigned long orig_lifetime, exp_time;
383 u32 last_hop_metric, new_metric;
384 bool process = true;
385
386 rcu_read_lock();
387 sta = sta_info_get(sdata, mgmt->sa);
388 if (!sta) {
389 rcu_read_unlock();
390 return 0;
391 }
392
393 last_hop_metric = airtime_link_metric_get(local, sta);
394 /* Update and check originator routing info */
395 fresh_info = true;
396
397 switch (action) {
398 case MPATH_PREQ:
399 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
400 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
401 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
402 orig_metric = PREQ_IE_METRIC(hwmp_ie);
403 break;
404 case MPATH_PREP:
405 /* Originator here refers to the MP that was the target in the
406 * Path Request. We divert from the nomenclature in the draft
407 * so that we can easily use a single function to gather path
408 * information from both PREQ and PREP frames.
409 */
410 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
411 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
412 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
413 orig_metric = PREP_IE_METRIC(hwmp_ie);
414 break;
415 default:
416 rcu_read_unlock();
417 return 0;
418 }
419 new_metric = orig_metric + last_hop_metric;
420 if (new_metric < orig_metric)
421 new_metric = MAX_METRIC;
422 exp_time = TU_TO_EXP_TIME(orig_lifetime);
423
424 if (ether_addr_equal(orig_addr, sdata->vif.addr)) {
425 /* This MP is the originator, we are not interested in this
426 * frame, except for updating transmitter's path info.
427 */
428 process = false;
429 fresh_info = false;
430 } else {
431 mpath = mesh_path_lookup(sdata, orig_addr);
432 if (mpath) {
433 spin_lock_bh(&mpath->state_lock);
434 if (mpath->flags & MESH_PATH_FIXED)
435 fresh_info = false;
436 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
437 (mpath->flags & MESH_PATH_SN_VALID)) {
438 if (SN_GT(mpath->sn, orig_sn) ||
439 (mpath->sn == orig_sn &&
440 new_metric >= mpath->metric)) {
441 process = false;
442 fresh_info = false;
443 }
444 }
445 } else {
446 mpath = mesh_path_add(sdata, orig_addr);
447 if (IS_ERR(mpath)) {
448 rcu_read_unlock();
449 return 0;
450 }
451 spin_lock_bh(&mpath->state_lock);
452 }
453
454 if (fresh_info) {
455 mesh_path_assign_nexthop(mpath, sta);
456 mpath->flags |= MESH_PATH_SN_VALID;
457 mpath->metric = new_metric;
458 mpath->sn = orig_sn;
459 mpath->exp_time = time_after(mpath->exp_time, exp_time)
460 ? mpath->exp_time : exp_time;
461 mesh_path_activate(mpath);
462 spin_unlock_bh(&mpath->state_lock);
463 mesh_path_tx_pending(mpath);
464 /* draft says preq_id should be saved to, but there does
465 * not seem to be any use for it, skipping by now
466 */
467 } else
468 spin_unlock_bh(&mpath->state_lock);
469 }
470
471 /* Update and check transmitter routing info */
472 ta = mgmt->sa;
473 if (ether_addr_equal(orig_addr, ta))
474 fresh_info = false;
475 else {
476 fresh_info = true;
477
478 mpath = mesh_path_lookup(sdata, ta);
479 if (mpath) {
480 spin_lock_bh(&mpath->state_lock);
481 if ((mpath->flags & MESH_PATH_FIXED) ||
482 ((mpath->flags & MESH_PATH_ACTIVE) &&
483 (last_hop_metric > mpath->metric)))
484 fresh_info = false;
485 } else {
486 mpath = mesh_path_add(sdata, ta);
487 if (IS_ERR(mpath)) {
488 rcu_read_unlock();
489 return 0;
490 }
491 spin_lock_bh(&mpath->state_lock);
492 }
493
494 if (fresh_info) {
495 mesh_path_assign_nexthop(mpath, sta);
496 mpath->metric = last_hop_metric;
497 mpath->exp_time = time_after(mpath->exp_time, exp_time)
498 ? mpath->exp_time : exp_time;
499 mesh_path_activate(mpath);
500 spin_unlock_bh(&mpath->state_lock);
501 mesh_path_tx_pending(mpath);
502 } else
503 spin_unlock_bh(&mpath->state_lock);
504 }
505
506 rcu_read_unlock();
507
508 return process ? new_metric : 0;
509 }
510
hwmp_preq_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * preq_elem,u32 metric)511 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
512 struct ieee80211_mgmt *mgmt,
513 const u8 *preq_elem, u32 metric)
514 {
515 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
516 struct mesh_path *mpath = NULL;
517 const u8 *target_addr, *orig_addr;
518 const u8 *da;
519 u8 target_flags, ttl, flags;
520 u32 orig_sn, target_sn, lifetime, orig_metric;
521 bool reply = false;
522 bool forward = true;
523 bool root_is_gate;
524
525 /* Update target SN, if present */
526 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
527 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
528 target_sn = PREQ_IE_TARGET_SN(preq_elem);
529 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
530 target_flags = PREQ_IE_TARGET_F(preq_elem);
531 orig_metric = metric;
532 /* Proactive PREQ gate announcements */
533 flags = PREQ_IE_FLAGS(preq_elem);
534 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
535
536 mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
537
538 if (ether_addr_equal(target_addr, sdata->vif.addr)) {
539 mhwmp_dbg(sdata, "PREQ is for us\n");
540 forward = false;
541 reply = true;
542 metric = 0;
543 if (time_after(jiffies, ifmsh->last_sn_update +
544 net_traversal_jiffies(sdata)) ||
545 time_before(jiffies, ifmsh->last_sn_update)) {
546 ++ifmsh->sn;
547 ifmsh->last_sn_update = jiffies;
548 }
549 target_sn = ifmsh->sn;
550 } else if (is_broadcast_ether_addr(target_addr) &&
551 (target_flags & IEEE80211_PREQ_TO_FLAG)) {
552 rcu_read_lock();
553 mpath = mesh_path_lookup(sdata, orig_addr);
554 if (mpath) {
555 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
556 reply = true;
557 target_addr = sdata->vif.addr;
558 target_sn = ++ifmsh->sn;
559 metric = 0;
560 ifmsh->last_sn_update = jiffies;
561 }
562 if (root_is_gate)
563 mesh_path_add_gate(mpath);
564 }
565 rcu_read_unlock();
566 } else {
567 rcu_read_lock();
568 mpath = mesh_path_lookup(sdata, target_addr);
569 if (mpath) {
570 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
571 SN_LT(mpath->sn, target_sn)) {
572 mpath->sn = target_sn;
573 mpath->flags |= MESH_PATH_SN_VALID;
574 } else if ((!(target_flags & MP_F_DO)) &&
575 (mpath->flags & MESH_PATH_ACTIVE)) {
576 reply = true;
577 metric = mpath->metric;
578 target_sn = mpath->sn;
579 if (target_flags & MP_F_RF)
580 target_flags |= MP_F_DO;
581 else
582 forward = false;
583 }
584 }
585 rcu_read_unlock();
586 }
587
588 if (reply) {
589 lifetime = PREQ_IE_LIFETIME(preq_elem);
590 ttl = ifmsh->mshcfg.element_ttl;
591 if (ttl != 0) {
592 mhwmp_dbg(sdata, "replying to the PREQ\n");
593 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
594 orig_sn, 0, target_addr,
595 target_sn, mgmt->sa, 0, ttl,
596 lifetime, metric, 0, sdata);
597 } else {
598 ifmsh->mshstats.dropped_frames_ttl++;
599 }
600 }
601
602 if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
603 u32 preq_id;
604 u8 hopcount;
605
606 ttl = PREQ_IE_TTL(preq_elem);
607 lifetime = PREQ_IE_LIFETIME(preq_elem);
608 if (ttl <= 1) {
609 ifmsh->mshstats.dropped_frames_ttl++;
610 return;
611 }
612 mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
613 --ttl;
614 preq_id = PREQ_IE_PREQ_ID(preq_elem);
615 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
616 da = (mpath && mpath->is_root) ?
617 mpath->rann_snd_addr : broadcast_addr;
618
619 if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
620 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
621 target_sn = PREQ_IE_TARGET_SN(preq_elem);
622 metric = orig_metric;
623 }
624
625 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
626 orig_sn, target_flags, target_addr,
627 target_sn, da, hopcount, ttl, lifetime,
628 metric, preq_id, sdata);
629 if (!is_multicast_ether_addr(da))
630 ifmsh->mshstats.fwded_unicast++;
631 else
632 ifmsh->mshstats.fwded_mcast++;
633 ifmsh->mshstats.fwded_frames++;
634 }
635 }
636
637
638 static inline struct sta_info *
next_hop_deref_protected(struct mesh_path * mpath)639 next_hop_deref_protected(struct mesh_path *mpath)
640 {
641 return rcu_dereference_protected(mpath->next_hop,
642 lockdep_is_held(&mpath->state_lock));
643 }
644
645
hwmp_prep_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * prep_elem,u32 metric)646 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
647 struct ieee80211_mgmt *mgmt,
648 const u8 *prep_elem, u32 metric)
649 {
650 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
651 struct mesh_path *mpath;
652 const u8 *target_addr, *orig_addr;
653 u8 ttl, hopcount, flags;
654 u8 next_hop[ETH_ALEN];
655 u32 target_sn, orig_sn, lifetime;
656
657 mhwmp_dbg(sdata, "received PREP from %pM\n",
658 PREP_IE_TARGET_ADDR(prep_elem));
659
660 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
661 if (ether_addr_equal(orig_addr, sdata->vif.addr))
662 /* destination, no forwarding required */
663 return;
664
665 if (!ifmsh->mshcfg.dot11MeshForwarding)
666 return;
667
668 ttl = PREP_IE_TTL(prep_elem);
669 if (ttl <= 1) {
670 sdata->u.mesh.mshstats.dropped_frames_ttl++;
671 return;
672 }
673
674 rcu_read_lock();
675 mpath = mesh_path_lookup(sdata, orig_addr);
676 if (mpath)
677 spin_lock_bh(&mpath->state_lock);
678 else
679 goto fail;
680 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
681 spin_unlock_bh(&mpath->state_lock);
682 goto fail;
683 }
684 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
685 spin_unlock_bh(&mpath->state_lock);
686 --ttl;
687 flags = PREP_IE_FLAGS(prep_elem);
688 lifetime = PREP_IE_LIFETIME(prep_elem);
689 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
690 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
691 target_sn = PREP_IE_TARGET_SN(prep_elem);
692 orig_sn = PREP_IE_ORIG_SN(prep_elem);
693
694 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0,
695 target_addr, target_sn, next_hop, hopcount,
696 ttl, lifetime, metric, 0, sdata);
697 rcu_read_unlock();
698
699 sdata->u.mesh.mshstats.fwded_unicast++;
700 sdata->u.mesh.mshstats.fwded_frames++;
701 return;
702
703 fail:
704 rcu_read_unlock();
705 sdata->u.mesh.mshstats.dropped_frames_no_route++;
706 }
707
hwmp_perr_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const u8 * perr_elem)708 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
709 struct ieee80211_mgmt *mgmt,
710 const u8 *perr_elem)
711 {
712 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
713 struct mesh_path *mpath;
714 u8 ttl;
715 const u8 *ta, *target_addr;
716 u32 target_sn;
717 u16 target_rcode;
718
719 ta = mgmt->sa;
720 ttl = PERR_IE_TTL(perr_elem);
721 if (ttl <= 1) {
722 ifmsh->mshstats.dropped_frames_ttl++;
723 return;
724 }
725 ttl--;
726 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
727 target_sn = PERR_IE_TARGET_SN(perr_elem);
728 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
729
730 rcu_read_lock();
731 mpath = mesh_path_lookup(sdata, target_addr);
732 if (mpath) {
733 struct sta_info *sta;
734
735 spin_lock_bh(&mpath->state_lock);
736 sta = next_hop_deref_protected(mpath);
737 if (mpath->flags & MESH_PATH_ACTIVE &&
738 ether_addr_equal(ta, sta->sta.addr) &&
739 (!(mpath->flags & MESH_PATH_SN_VALID) ||
740 SN_GT(target_sn, mpath->sn))) {
741 mpath->flags &= ~MESH_PATH_ACTIVE;
742 mpath->sn = target_sn;
743 spin_unlock_bh(&mpath->state_lock);
744 if (!ifmsh->mshcfg.dot11MeshForwarding)
745 goto endperr;
746 mesh_path_error_tx(sdata, ttl, target_addr,
747 target_sn, target_rcode,
748 broadcast_addr);
749 } else
750 spin_unlock_bh(&mpath->state_lock);
751 }
752 endperr:
753 rcu_read_unlock();
754 }
755
hwmp_rann_frame_process(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,const struct ieee80211_rann_ie * rann)756 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
757 struct ieee80211_mgmt *mgmt,
758 const struct ieee80211_rann_ie *rann)
759 {
760 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
761 struct ieee80211_local *local = sdata->local;
762 struct sta_info *sta;
763 struct mesh_path *mpath;
764 u8 ttl, flags, hopcount;
765 const u8 *orig_addr;
766 u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
767 bool root_is_gate;
768
769 ttl = rann->rann_ttl;
770 flags = rann->rann_flags;
771 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
772 orig_addr = rann->rann_addr;
773 orig_sn = le32_to_cpu(rann->rann_seq);
774 interval = le32_to_cpu(rann->rann_interval);
775 hopcount = rann->rann_hopcount;
776 hopcount++;
777 orig_metric = le32_to_cpu(rann->rann_metric);
778
779 /* Ignore our own RANNs */
780 if (ether_addr_equal(orig_addr, sdata->vif.addr))
781 return;
782
783 mhwmp_dbg(sdata,
784 "received RANN from %pM via neighbour %pM (is_gate=%d)\n",
785 orig_addr, mgmt->sa, root_is_gate);
786
787 rcu_read_lock();
788 sta = sta_info_get(sdata, mgmt->sa);
789 if (!sta) {
790 rcu_read_unlock();
791 return;
792 }
793
794 last_hop_metric = airtime_link_metric_get(local, sta);
795 new_metric = orig_metric + last_hop_metric;
796 if (new_metric < orig_metric)
797 new_metric = MAX_METRIC;
798
799 mpath = mesh_path_lookup(sdata, orig_addr);
800 if (!mpath) {
801 mpath = mesh_path_add(sdata, orig_addr);
802 if (IS_ERR(mpath)) {
803 rcu_read_unlock();
804 sdata->u.mesh.mshstats.dropped_frames_no_route++;
805 return;
806 }
807 }
808
809 if (!(SN_LT(mpath->sn, orig_sn)) &&
810 !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
811 rcu_read_unlock();
812 return;
813 }
814
815 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
816 (time_after(jiffies, mpath->last_preq_to_root +
817 root_path_confirmation_jiffies(sdata)) ||
818 time_before(jiffies, mpath->last_preq_to_root))) &&
819 !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
820 mhwmp_dbg(sdata,
821 "time to refresh root mpath %pM\n",
822 orig_addr);
823 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
824 mpath->last_preq_to_root = jiffies;
825 }
826
827 mpath->sn = orig_sn;
828 mpath->rann_metric = new_metric;
829 mpath->is_root = true;
830 /* Recording RANNs sender address to send individually
831 * addressed PREQs destined for root mesh STA */
832 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
833
834 if (root_is_gate)
835 mesh_path_add_gate(mpath);
836
837 if (ttl <= 1) {
838 ifmsh->mshstats.dropped_frames_ttl++;
839 rcu_read_unlock();
840 return;
841 }
842 ttl--;
843
844 if (ifmsh->mshcfg.dot11MeshForwarding) {
845 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
846 orig_sn, 0, NULL, 0, broadcast_addr,
847 hopcount, ttl, interval,
848 new_metric, 0, sdata);
849 }
850
851 rcu_read_unlock();
852 }
853
854
mesh_rx_path_sel_frame(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)855 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
856 struct ieee80211_mgmt *mgmt, size_t len)
857 {
858 struct ieee802_11_elems elems;
859 size_t baselen;
860 u32 last_hop_metric;
861 struct sta_info *sta;
862
863 /* need action_code */
864 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
865 return;
866
867 rcu_read_lock();
868 sta = sta_info_get(sdata, mgmt->sa);
869 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) {
870 rcu_read_unlock();
871 return;
872 }
873 rcu_read_unlock();
874
875 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
876 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
877 len - baselen, false, &elems);
878
879 if (elems.preq) {
880 if (elems.preq_len != 37)
881 /* Right now we support just 1 destination and no AE */
882 return;
883 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
884 MPATH_PREQ);
885 if (last_hop_metric)
886 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
887 last_hop_metric);
888 }
889 if (elems.prep) {
890 if (elems.prep_len != 31)
891 /* Right now we support no AE */
892 return;
893 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
894 MPATH_PREP);
895 if (last_hop_metric)
896 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
897 last_hop_metric);
898 }
899 if (elems.perr) {
900 if (elems.perr_len != 15)
901 /* Right now we support only one destination per PERR */
902 return;
903 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
904 }
905 if (elems.rann)
906 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
907 }
908
909 /**
910 * mesh_queue_preq - queue a PREQ to a given destination
911 *
912 * @mpath: mesh path to discover
913 * @flags: special attributes of the PREQ to be sent
914 *
915 * Locking: the function must be called from within a rcu read lock block.
916 *
917 */
mesh_queue_preq(struct mesh_path * mpath,u8 flags)918 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
919 {
920 struct ieee80211_sub_if_data *sdata = mpath->sdata;
921 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
922 struct mesh_preq_queue *preq_node;
923
924 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
925 if (!preq_node) {
926 mhwmp_dbg(sdata, "could not allocate PREQ node\n");
927 return;
928 }
929
930 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
931 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
932 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
933 kfree(preq_node);
934 if (printk_ratelimit())
935 mhwmp_dbg(sdata, "PREQ node queue full\n");
936 return;
937 }
938
939 spin_lock(&mpath->state_lock);
940 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
941 spin_unlock(&mpath->state_lock);
942 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
943 kfree(preq_node);
944 return;
945 }
946
947 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
948 preq_node->flags = flags;
949
950 mpath->flags |= MESH_PATH_REQ_QUEUED;
951 spin_unlock(&mpath->state_lock);
952
953 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
954 ++ifmsh->preq_queue_len;
955 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
956
957 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
958 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
959
960 else if (time_before(jiffies, ifmsh->last_preq)) {
961 /* avoid long wait if did not send preqs for a long time
962 * and jiffies wrapped around
963 */
964 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
965 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
966 } else
967 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
968 min_preq_int_jiff(sdata));
969 }
970
971 /**
972 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
973 *
974 * @sdata: local mesh subif
975 */
mesh_path_start_discovery(struct ieee80211_sub_if_data * sdata)976 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
977 {
978 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
979 struct mesh_preq_queue *preq_node;
980 struct mesh_path *mpath;
981 u8 ttl, target_flags;
982 const u8 *da;
983 u32 lifetime;
984
985 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
986 if (!ifmsh->preq_queue_len ||
987 time_before(jiffies, ifmsh->last_preq +
988 min_preq_int_jiff(sdata))) {
989 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
990 return;
991 }
992
993 preq_node = list_first_entry(&ifmsh->preq_queue.list,
994 struct mesh_preq_queue, list);
995 list_del(&preq_node->list);
996 --ifmsh->preq_queue_len;
997 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
998
999 rcu_read_lock();
1000 mpath = mesh_path_lookup(sdata, preq_node->dst);
1001 if (!mpath)
1002 goto enddiscovery;
1003
1004 spin_lock_bh(&mpath->state_lock);
1005 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1006 if (preq_node->flags & PREQ_Q_F_START) {
1007 if (mpath->flags & MESH_PATH_RESOLVING) {
1008 spin_unlock_bh(&mpath->state_lock);
1009 goto enddiscovery;
1010 } else {
1011 mpath->flags &= ~MESH_PATH_RESOLVED;
1012 mpath->flags |= MESH_PATH_RESOLVING;
1013 mpath->discovery_retries = 0;
1014 mpath->discovery_timeout = disc_timeout_jiff(sdata);
1015 }
1016 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
1017 mpath->flags & MESH_PATH_RESOLVED) {
1018 mpath->flags &= ~MESH_PATH_RESOLVING;
1019 spin_unlock_bh(&mpath->state_lock);
1020 goto enddiscovery;
1021 }
1022
1023 ifmsh->last_preq = jiffies;
1024
1025 if (time_after(jiffies, ifmsh->last_sn_update +
1026 net_traversal_jiffies(sdata)) ||
1027 time_before(jiffies, ifmsh->last_sn_update)) {
1028 ++ifmsh->sn;
1029 sdata->u.mesh.last_sn_update = jiffies;
1030 }
1031 lifetime = default_lifetime(sdata);
1032 ttl = sdata->u.mesh.mshcfg.element_ttl;
1033 if (ttl == 0) {
1034 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1035 spin_unlock_bh(&mpath->state_lock);
1036 goto enddiscovery;
1037 }
1038
1039 if (preq_node->flags & PREQ_Q_F_REFRESH)
1040 target_flags = MP_F_DO;
1041 else
1042 target_flags = MP_F_RF;
1043
1044 spin_unlock_bh(&mpath->state_lock);
1045 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
1046 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
1047 target_flags, mpath->dst, mpath->sn, da, 0,
1048 ttl, lifetime, 0, ifmsh->preq_id++, sdata);
1049 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1050
1051 enddiscovery:
1052 rcu_read_unlock();
1053 kfree(preq_node);
1054 }
1055
1056 /**
1057 * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
1058 *
1059 * @skb: 802.11 frame to be sent
1060 * @sdata: network subif the frame will be sent through
1061 *
1062 * Lookup next hop for given skb and start path discovery if no
1063 * forwarding information is found.
1064 *
1065 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1066 * skb is freeed here if no mpath could be allocated.
1067 */
mesh_nexthop_resolve(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1068 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
1069 struct sk_buff *skb)
1070 {
1071 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1072 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1073 struct mesh_path *mpath;
1074 struct sk_buff *skb_to_free = NULL;
1075 u8 *target_addr = hdr->addr3;
1076 int err = 0;
1077
1078 /* Nulls are only sent to peers for PS and should be pre-addressed */
1079 if (ieee80211_is_qos_nullfunc(hdr->frame_control))
1080 return 0;
1081
1082 rcu_read_lock();
1083 err = mesh_nexthop_lookup(sdata, skb);
1084 if (!err)
1085 goto endlookup;
1086
1087 /* no nexthop found, start resolving */
1088 mpath = mesh_path_lookup(sdata, target_addr);
1089 if (!mpath) {
1090 mpath = mesh_path_add(sdata, target_addr);
1091 if (IS_ERR(mpath)) {
1092 mesh_path_discard_frame(sdata, skb);
1093 err = PTR_ERR(mpath);
1094 goto endlookup;
1095 }
1096 }
1097
1098 if (!(mpath->flags & MESH_PATH_RESOLVING))
1099 mesh_queue_preq(mpath, PREQ_Q_F_START);
1100
1101 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1102 skb_to_free = skb_dequeue(&mpath->frame_queue);
1103
1104 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1105 ieee80211_set_qos_hdr(sdata, skb);
1106 skb_queue_tail(&mpath->frame_queue, skb);
1107 err = -ENOENT;
1108 if (skb_to_free)
1109 mesh_path_discard_frame(sdata, skb_to_free);
1110
1111 endlookup:
1112 rcu_read_unlock();
1113 return err;
1114 }
1115
1116 /**
1117 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1118 * this function is considered "using" the associated mpath, so preempt a path
1119 * refresh if this mpath expires soon.
1120 *
1121 * @skb: 802.11 frame to be sent
1122 * @sdata: network subif the frame will be sent through
1123 *
1124 * Returns: 0 if the next hop was found. Nonzero otherwise.
1125 */
mesh_nexthop_lookup(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)1126 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
1127 struct sk_buff *skb)
1128 {
1129 struct mesh_path *mpath;
1130 struct sta_info *next_hop;
1131 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1132 u8 *target_addr = hdr->addr3;
1133 int err = -ENOENT;
1134
1135 rcu_read_lock();
1136 mpath = mesh_path_lookup(sdata, target_addr);
1137
1138 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1139 goto endlookup;
1140
1141 if (time_after(jiffies,
1142 mpath->exp_time -
1143 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1144 ether_addr_equal(sdata->vif.addr, hdr->addr4) &&
1145 !(mpath->flags & MESH_PATH_RESOLVING) &&
1146 !(mpath->flags & MESH_PATH_FIXED))
1147 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1148
1149 next_hop = rcu_dereference(mpath->next_hop);
1150 if (next_hop) {
1151 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1152 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1153 ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
1154 err = 0;
1155 }
1156
1157 endlookup:
1158 rcu_read_unlock();
1159 return err;
1160 }
1161
mesh_path_timer(unsigned long data)1162 void mesh_path_timer(unsigned long data)
1163 {
1164 struct mesh_path *mpath = (void *) data;
1165 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1166 int ret;
1167
1168 if (sdata->local->quiescing)
1169 return;
1170
1171 spin_lock_bh(&mpath->state_lock);
1172 if (mpath->flags & MESH_PATH_RESOLVED ||
1173 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1174 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1175 spin_unlock_bh(&mpath->state_lock);
1176 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1177 ++mpath->discovery_retries;
1178 mpath->discovery_timeout *= 2;
1179 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1180 spin_unlock_bh(&mpath->state_lock);
1181 mesh_queue_preq(mpath, 0);
1182 } else {
1183 mpath->flags = 0;
1184 mpath->exp_time = jiffies;
1185 spin_unlock_bh(&mpath->state_lock);
1186 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1187 ret = mesh_path_send_to_gates(mpath);
1188 if (ret)
1189 mhwmp_dbg(sdata, "no gate was reachable\n");
1190 } else
1191 mesh_path_flush_pending(mpath);
1192 }
1193 }
1194
mesh_path_tx_root_frame(struct ieee80211_sub_if_data * sdata)1195 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1196 {
1197 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1198 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1199 u8 flags, target_flags = 0;
1200
1201 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1202 ? RANN_FLAG_IS_GATE : 0;
1203
1204 switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
1205 case IEEE80211_PROACTIVE_RANN:
1206 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1207 ++ifmsh->sn, 0, NULL, 0, broadcast_addr,
1208 0, ifmsh->mshcfg.element_ttl,
1209 interval, 0, 0, sdata);
1210 break;
1211 case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
1212 flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
1213 case IEEE80211_PROACTIVE_PREQ_NO_PREP:
1214 interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
1215 target_flags |= IEEE80211_PREQ_TO_FLAG |
1216 IEEE80211_PREQ_USN_FLAG;
1217 mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
1218 ++ifmsh->sn, target_flags,
1219 (u8 *) broadcast_addr, 0, broadcast_addr,
1220 0, ifmsh->mshcfg.element_ttl, interval,
1221 0, ifmsh->preq_id++, sdata);
1222 break;
1223 default:
1224 mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
1225 return;
1226 }
1227 }
1228