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spi-topcliff-pch: Fix issue for transmitting over 4KByte
[zen-stable.git] / net / mac80211 / mesh_hwmp.c
blob54df1b2bafd2882454bc71b3a018161f0f83e5e3
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;
117 struct ieee80211_mgmt *mgmt;
118 u8 *pos, ie_len;
119 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
120 sizeof(mgmt->u.action.u.mesh_action);
121
122 skb = dev_alloc_skb(local->tx_headroom +
123 hdr_len +
124 2 + 37); /* max HWMP IE */
125 if (!skb)
126 return -1;
127 skb_reserve(skb, local->tx_headroom);
128 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
129 memset(mgmt, 0, hdr_len);
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;
244 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
245 struct ieee80211_mgmt *mgmt;
246 u8 *pos, ie_len;
247 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
248 sizeof(mgmt->u.action.u.mesh_action);
249
250 if (time_before(jiffies, ifmsh->next_perr))
251 return -EAGAIN;
252
253 skb = dev_alloc_skb(local->tx_headroom +
254 hdr_len +
255 2 + 15 /* PERR IE */);
256 if (!skb)
257 return -1;
258 skb_reserve(skb, local->tx_headroom);
259 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
260 memset(mgmt, 0, hdr_len);
261 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
262 IEEE80211_STYPE_ACTION);
263
264 memcpy(mgmt->da, ra, ETH_ALEN);
265 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
266 /* BSSID == SA */
267 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
268 mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
269 mgmt->u.action.u.mesh_action.action_code =
270 WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
271 ie_len = 15;
272 pos = skb_put(skb, 2 + ie_len);
273 *pos++ = WLAN_EID_PERR;
274 *pos++ = ie_len;
275 /* ttl */
276 *pos++ = ttl;
277 /* number of destinations */
278 *pos++ = 1;
279 /*
280 * flags bit, bit 1 is unset if we know the sequence number and
281 * bit 2 is set if we have a reason code
282 */
283 *pos = 0;
284 if (!target_sn)
285 *pos |= MP_F_USN;
286 if (target_rcode)
287 *pos |= MP_F_RCODE;
288 pos++;
289 memcpy(pos, target, ETH_ALEN);
290 pos += ETH_ALEN;
291 memcpy(pos, &target_sn, 4);
292 pos += 4;
293 memcpy(pos, &target_rcode, 2);
294
295 /* see note in function header */
296 prepare_frame_for_deferred_tx(sdata, skb);
297 ifmsh->next_perr = TU_TO_EXP_TIME(
298 ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
299 ieee80211_add_pending_skb(local, skb);
300 return 0;
301 }
302
303 void ieee80211s_update_metric(struct ieee80211_local *local,
304 struct sta_info *stainfo, struct sk_buff *skb)
305 {
306 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
307 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
308 int failed;
309
310 if (!ieee80211_is_data(hdr->frame_control))
311 return;
312
313 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
314
315 /* moving average, scaled to 100 */
316 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
317 if (stainfo->fail_avg > 95)
318 mesh_plink_broken(stainfo);
319 }
320
321 static u32 airtime_link_metric_get(struct ieee80211_local *local,
322 struct sta_info *sta)
323 {
324 struct ieee80211_supported_band *sband;
325 /* This should be adjusted for each device */
326 int device_constant = 1 << ARITH_SHIFT;
327 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
328 int s_unit = 1 << ARITH_SHIFT;
329 int rate, err;
330 u32 tx_time, estimated_retx;
331 u64 result;
332
333 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
334
335 if (sta->fail_avg >= 100)
336 return MAX_METRIC;
337
338 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
339 return MAX_METRIC;
340
341 err = (sta->fail_avg << ARITH_SHIFT) / 100;
342
343 /* bitrate is in units of 100 Kbps, while we need rate in units of
344 * 1Mbps. This will be corrected on tx_time computation.
345 */
346 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
347 tx_time = (device_constant + 10 * test_frame_len / rate);
348 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
349 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
350 return (u32)result;
351 }
352
353 /**
354 * hwmp_route_info_get - Update routing info to originator and transmitter
355 *
356 * @sdata: local mesh subif
357 * @mgmt: mesh management frame
358 * @hwmp_ie: hwmp information element (PREP or PREQ)
359 *
360 * This function updates the path routing information to the originator and the
361 * transmitter of a HWMP PREQ or PREP frame.
362 *
363 * Returns: metric to frame originator or 0 if the frame should not be further
364 * processed
365 *
366 * Notes: this function is the only place (besides user-provided info) where
367 * path routing information is updated.
368 */
369 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
370 struct ieee80211_mgmt *mgmt,
371 u8 *hwmp_ie, enum mpath_frame_type action)
372 {
373 struct ieee80211_local *local = sdata->local;
374 struct mesh_path *mpath;
375 struct sta_info *sta;
376 bool fresh_info;
377 u8 *orig_addr, *ta;
378 u32 orig_sn, orig_metric;
379 unsigned long orig_lifetime, exp_time;
380 u32 last_hop_metric, new_metric;
381 bool process = true;
382
383 rcu_read_lock();
384 sta = sta_info_get(sdata, mgmt->sa);
385 if (!sta) {
386 rcu_read_unlock();
387 return 0;
388 }
389
390 last_hop_metric = airtime_link_metric_get(local, sta);
391 /* Update and check originator routing info */
392 fresh_info = true;
393
394 switch (action) {
395 case MPATH_PREQ:
396 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
397 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
398 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
399 orig_metric = PREQ_IE_METRIC(hwmp_ie);
400 break;
401 case MPATH_PREP:
402 /* Originator here refers to the MP that was the target in the
403 * Path Request. We divert from the nomenclature in the draft
404 * so that we can easily use a single function to gather path
405 * information from both PREQ and PREP frames.
406 */
407 orig_addr = PREP_IE_TARGET_ADDR(hwmp_ie);
408 orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
409 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
410 orig_metric = PREP_IE_METRIC(hwmp_ie);
411 break;
412 default:
413 rcu_read_unlock();
414 return 0;
415 }
416 new_metric = orig_metric + last_hop_metric;
417 if (new_metric < orig_metric)
418 new_metric = MAX_METRIC;
419 exp_time = TU_TO_EXP_TIME(orig_lifetime);
420
421 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) {
422 /* This MP is the originator, we are not interested in this
423 * frame, except for updating transmitter's path info.
424 */
425 process = false;
426 fresh_info = false;
427 } else {
428 mpath = mesh_path_lookup(orig_addr, sdata);
429 if (mpath) {
430 spin_lock_bh(&mpath->state_lock);
431 if (mpath->flags & MESH_PATH_FIXED)
432 fresh_info = false;
433 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
434 (mpath->flags & MESH_PATH_SN_VALID)) {
435 if (SN_GT(mpath->sn, orig_sn) ||
436 (mpath->sn == orig_sn &&
437 new_metric >= mpath->metric)) {
438 process = false;
439 fresh_info = false;
440 }
441 }
442 } else {
443 mesh_path_add(orig_addr, sdata);
444 mpath = mesh_path_lookup(orig_addr, sdata);
445 if (!mpath) {
446 rcu_read_unlock();
447 return 0;
448 }
449 spin_lock_bh(&mpath->state_lock);
450 }
451
452 if (fresh_info) {
453 mesh_path_assign_nexthop(mpath, sta);
454 mpath->flags |= MESH_PATH_SN_VALID;
455 mpath->metric = new_metric;
456 mpath->sn = orig_sn;
457 mpath->exp_time = time_after(mpath->exp_time, exp_time)
458 ? mpath->exp_time : exp_time;
459 mesh_path_activate(mpath);
460 spin_unlock_bh(&mpath->state_lock);
461 mesh_path_tx_pending(mpath);
462 /* draft says preq_id should be saved to, but there does
463 * not seem to be any use for it, skipping by now
464 */
465 } else
466 spin_unlock_bh(&mpath->state_lock);
467 }
468
469 /* Update and check transmitter routing info */
470 ta = mgmt->sa;
471 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
472 fresh_info = false;
473 else {
474 fresh_info = true;
475
476 mpath = mesh_path_lookup(ta, sdata);
477 if (mpath) {
478 spin_lock_bh(&mpath->state_lock);
479 if ((mpath->flags & MESH_PATH_FIXED) ||
480 ((mpath->flags & MESH_PATH_ACTIVE) &&
481 (last_hop_metric > mpath->metric)))
482 fresh_info = false;
483 } else {
484 mesh_path_add(ta, sdata);
485 mpath = mesh_path_lookup(ta, sdata);
486 if (!mpath) {
487 rcu_read_unlock();
488 return 0;
489 }
490 spin_lock_bh(&mpath->state_lock);
491 }
492
493 if (fresh_info) {
494 mesh_path_assign_nexthop(mpath, sta);
495 mpath->metric = last_hop_metric;
496 mpath->exp_time = time_after(mpath->exp_time, exp_time)
497 ? mpath->exp_time : exp_time;
498 mesh_path_activate(mpath);
499 spin_unlock_bh(&mpath->state_lock);
500 mesh_path_tx_pending(mpath);
501 } else
502 spin_unlock_bh(&mpath->state_lock);
503 }
504
505 rcu_read_unlock();
506
507 return process ? new_metric : 0;
508 }
509
510 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
511 struct ieee80211_mgmt *mgmt,
512 u8 *preq_elem, u32 metric)
513 {
514 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
515 struct mesh_path *mpath;
516 u8 *target_addr, *orig_addr;
517 u8 target_flags, ttl;
518 u32 orig_sn, target_sn, lifetime;
519 bool reply = false;
520 bool forward = true;
521
522 /* Update target SN, if present */
523 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
524 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
525 target_sn = PREQ_IE_TARGET_SN(preq_elem);
526 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
527 target_flags = PREQ_IE_TARGET_F(preq_elem);
528
529 mhwmp_dbg("received PREQ from %pM", orig_addr);
530
531 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) {
532 mhwmp_dbg("PREQ is for us");
533 forward = false;
534 reply = true;
535 metric = 0;
536 if (time_after(jiffies, ifmsh->last_sn_update +
537 net_traversal_jiffies(sdata)) ||
538 time_before(jiffies, ifmsh->last_sn_update)) {
539 target_sn = ++ifmsh->sn;
540 ifmsh->last_sn_update = jiffies;
541 }
542 } else {
543 rcu_read_lock();
544 mpath = mesh_path_lookup(target_addr, sdata);
545 if (mpath) {
546 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
547 SN_LT(mpath->sn, target_sn)) {
548 mpath->sn = target_sn;
549 mpath->flags |= MESH_PATH_SN_VALID;
550 } else if ((!(target_flags & MP_F_DO)) &&
551 (mpath->flags & MESH_PATH_ACTIVE)) {
552 reply = true;
553 metric = mpath->metric;
554 target_sn = mpath->sn;
555 if (target_flags & MP_F_RF)
556 target_flags |= MP_F_DO;
557 else
558 forward = false;
559 }
560 }
561 rcu_read_unlock();
562 }
563
564 if (reply) {
565 lifetime = PREQ_IE_LIFETIME(preq_elem);
566 ttl = ifmsh->mshcfg.element_ttl;
567 if (ttl != 0) {
568 mhwmp_dbg("replying to the PREQ");
569 mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
570 cpu_to_le32(orig_sn), 0, target_addr,
571 cpu_to_le32(target_sn), mgmt->sa, 0, ttl,
572 cpu_to_le32(lifetime), cpu_to_le32(metric),
573 0, sdata);
574 } else
575 ifmsh->mshstats.dropped_frames_ttl++;
576 }
577
578 if (forward) {
579 u32 preq_id;
580 u8 hopcount, flags;
581
582 ttl = PREQ_IE_TTL(preq_elem);
583 lifetime = PREQ_IE_LIFETIME(preq_elem);
584 if (ttl <= 1) {
585 ifmsh->mshstats.dropped_frames_ttl++;
586 return;
587 }
588 mhwmp_dbg("forwarding the PREQ from %pM", orig_addr);
589 --ttl;
590 flags = PREQ_IE_FLAGS(preq_elem);
591 preq_id = PREQ_IE_PREQ_ID(preq_elem);
592 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
593 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
594 cpu_to_le32(orig_sn), target_flags, target_addr,
595 cpu_to_le32(target_sn), broadcast_addr,
596 hopcount, ttl, cpu_to_le32(lifetime),
597 cpu_to_le32(metric), cpu_to_le32(preq_id),
598 sdata);
599 ifmsh->mshstats.fwded_mcast++;
600 ifmsh->mshstats.fwded_frames++;
601 }
602 }
603
604
605 static inline struct sta_info *
606 next_hop_deref_protected(struct mesh_path *mpath)
607 {
608 return rcu_dereference_protected(mpath->next_hop,
609 lockdep_is_held(&mpath->state_lock));
610 }
611
612
613 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
614 struct ieee80211_mgmt *mgmt,
615 u8 *prep_elem, u32 metric)
616 {
617 struct mesh_path *mpath;
618 u8 *target_addr, *orig_addr;
619 u8 ttl, hopcount, flags;
620 u8 next_hop[ETH_ALEN];
621 u32 target_sn, orig_sn, lifetime;
622
623 mhwmp_dbg("received PREP from %pM", PREP_IE_ORIG_ADDR(prep_elem));
624
625 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
626 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0)
627 /* destination, no forwarding required */
628 return;
629
630 ttl = PREP_IE_TTL(prep_elem);
631 if (ttl <= 1) {
632 sdata->u.mesh.mshstats.dropped_frames_ttl++;
633 return;
634 }
635
636 rcu_read_lock();
637 mpath = mesh_path_lookup(orig_addr, sdata);
638 if (mpath)
639 spin_lock_bh(&mpath->state_lock);
640 else
641 goto fail;
642 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
643 spin_unlock_bh(&mpath->state_lock);
644 goto fail;
645 }
646 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
647 spin_unlock_bh(&mpath->state_lock);
648 --ttl;
649 flags = PREP_IE_FLAGS(prep_elem);
650 lifetime = PREP_IE_LIFETIME(prep_elem);
651 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
652 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
653 target_sn = PREP_IE_TARGET_SN(prep_elem);
654 orig_sn = PREP_IE_ORIG_SN(prep_elem);
655
656 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
657 cpu_to_le32(orig_sn), 0, target_addr,
658 cpu_to_le32(target_sn), next_hop, hopcount,
659 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
660 0, sdata);
661 rcu_read_unlock();
662
663 sdata->u.mesh.mshstats.fwded_unicast++;
664 sdata->u.mesh.mshstats.fwded_frames++;
665 return;
666
667 fail:
668 rcu_read_unlock();
669 sdata->u.mesh.mshstats.dropped_frames_no_route++;
670 }
671
672 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
673 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
674 {
675 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
676 struct mesh_path *mpath;
677 u8 ttl;
678 u8 *ta, *target_addr;
679 u32 target_sn;
680 u16 target_rcode;
681
682 ta = mgmt->sa;
683 ttl = PERR_IE_TTL(perr_elem);
684 if (ttl <= 1) {
685 ifmsh->mshstats.dropped_frames_ttl++;
686 return;
687 }
688 ttl--;
689 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
690 target_sn = PERR_IE_TARGET_SN(perr_elem);
691 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
692
693 rcu_read_lock();
694 mpath = mesh_path_lookup(target_addr, sdata);
695 if (mpath) {
696 spin_lock_bh(&mpath->state_lock);
697 if (mpath->flags & MESH_PATH_ACTIVE &&
698 memcmp(ta, next_hop_deref_protected(mpath)->sta.addr,
699 ETH_ALEN) == 0 &&
700 (!(mpath->flags & MESH_PATH_SN_VALID) ||
701 SN_GT(target_sn, mpath->sn))) {
702 mpath->flags &= ~MESH_PATH_ACTIVE;
703 mpath->sn = target_sn;
704 spin_unlock_bh(&mpath->state_lock);
705 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
706 cpu_to_le16(target_rcode),
707 broadcast_addr, sdata);
708 } else
709 spin_unlock_bh(&mpath->state_lock);
710 }
711 rcu_read_unlock();
712 }
713
714 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
715 struct ieee80211_mgmt *mgmt,
716 struct ieee80211_rann_ie *rann)
717 {
718 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
719 struct mesh_path *mpath;
720 u8 ttl, flags, hopcount;
721 u8 *orig_addr;
722 u32 orig_sn, metric;
723 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
724 bool root_is_gate;
725
726 ttl = rann->rann_ttl;
727 if (ttl <= 1) {
728 ifmsh->mshstats.dropped_frames_ttl++;
729 return;
730 }
731 ttl--;
732 flags = rann->rann_flags;
733 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
734 orig_addr = rann->rann_addr;
735 orig_sn = rann->rann_seq;
736 hopcount = rann->rann_hopcount;
737 hopcount++;
738 metric = rann->rann_metric;
739
740 /* Ignore our own RANNs */
741 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0)
742 return;
743
744 mhwmp_dbg("received RANN from %pM (is_gate=%d)", orig_addr,
745 root_is_gate);
746
747 rcu_read_lock();
748 mpath = mesh_path_lookup(orig_addr, sdata);
749 if (!mpath) {
750 mesh_path_add(orig_addr, sdata);
751 mpath = mesh_path_lookup(orig_addr, sdata);
752 if (!mpath) {
753 rcu_read_unlock();
754 sdata->u.mesh.mshstats.dropped_frames_no_route++;
755 return;
756 }
757 }
758
759 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
760 time_after(jiffies, mpath->exp_time - 1*HZ)) &&
761 !(mpath->flags & MESH_PATH_FIXED)) {
762 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
763 orig_addr);
764 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
765 }
766
767 if (mpath->sn < orig_sn) {
768 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
769 cpu_to_le32(orig_sn),
770 0, NULL, 0, broadcast_addr,
771 hopcount, ttl, cpu_to_le32(interval),
772 cpu_to_le32(metric + mpath->metric),
773 0, sdata);
774 mpath->sn = orig_sn;
775 }
776 if (root_is_gate)
777 mesh_path_add_gate(mpath);
778
779 rcu_read_unlock();
780 }
781
782
783 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
784 struct ieee80211_mgmt *mgmt,
785 size_t len)
786 {
787 struct ieee802_11_elems elems;
788 size_t baselen;
789 u32 last_hop_metric;
790 struct sta_info *sta;
791
792 /* need action_code */
793 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
794 return;
795
796 rcu_read_lock();
797 sta = sta_info_get(sdata, mgmt->sa);
798 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) {
799 rcu_read_unlock();
800 return;
801 }
802 rcu_read_unlock();
803
804 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
805 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
806 len - baselen, &elems);
807
808 if (elems.preq) {
809 if (elems.preq_len != 37)
810 /* Right now we support just 1 destination and no AE */
811 return;
812 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
813 MPATH_PREQ);
814 if (last_hop_metric)
815 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
816 last_hop_metric);
817 }
818 if (elems.prep) {
819 if (elems.prep_len != 31)
820 /* Right now we support no AE */
821 return;
822 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
823 MPATH_PREP);
824 if (last_hop_metric)
825 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
826 last_hop_metric);
827 }
828 if (elems.perr) {
829 if (elems.perr_len != 15)
830 /* Right now we support only one destination per PERR */
831 return;
832 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
833 }
834 if (elems.rann)
835 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
836 }
837
838 /**
839 * mesh_queue_preq - queue a PREQ to a given destination
840 *
841 * @mpath: mesh path to discover
842 * @flags: special attributes of the PREQ to be sent
843 *
844 * Locking: the function must be called from within a rcu read lock block.
845 *
846 */
847 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
848 {
849 struct ieee80211_sub_if_data *sdata = mpath->sdata;
850 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
851 struct mesh_preq_queue *preq_node;
852
853 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
854 if (!preq_node) {
855 mhwmp_dbg("could not allocate PREQ node");
856 return;
857 }
858
859 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
860 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
861 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
862 kfree(preq_node);
863 if (printk_ratelimit())
864 mhwmp_dbg("PREQ node queue full");
865 return;
866 }
867
868 spin_lock(&mpath->state_lock);
869 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
870 spin_unlock(&mpath->state_lock);
871 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
872 kfree(preq_node);
873 return;
874 }
875
876 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
877 preq_node->flags = flags;
878
879 mpath->flags |= MESH_PATH_REQ_QUEUED;
880 spin_unlock(&mpath->state_lock);
881
882 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
883 ++ifmsh->preq_queue_len;
884 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
885
886 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
887 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
888
889 else if (time_before(jiffies, ifmsh->last_preq)) {
890 /* avoid long wait if did not send preqs for a long time
891 * and jiffies wrapped around
892 */
893 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
894 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
895 } else
896 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
897 min_preq_int_jiff(sdata));
898 }
899
900 /**
901 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
902 *
903 * @sdata: local mesh subif
904 */
905 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
906 {
907 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
908 struct mesh_preq_queue *preq_node;
909 struct mesh_path *mpath;
910 u8 ttl, target_flags;
911 u32 lifetime;
912
913 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
914 if (!ifmsh->preq_queue_len ||
915 time_before(jiffies, ifmsh->last_preq +
916 min_preq_int_jiff(sdata))) {
917 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
918 return;
919 }
920
921 preq_node = list_first_entry(&ifmsh->preq_queue.list,
922 struct mesh_preq_queue, list);
923 list_del(&preq_node->list);
924 --ifmsh->preq_queue_len;
925 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
926
927 rcu_read_lock();
928 mpath = mesh_path_lookup(preq_node->dst, sdata);
929 if (!mpath)
930 goto enddiscovery;
931
932 spin_lock_bh(&mpath->state_lock);
933 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
934 if (preq_node->flags & PREQ_Q_F_START) {
935 if (mpath->flags & MESH_PATH_RESOLVING) {
936 spin_unlock_bh(&mpath->state_lock);
937 goto enddiscovery;
938 } else {
939 mpath->flags &= ~MESH_PATH_RESOLVED;
940 mpath->flags |= MESH_PATH_RESOLVING;
941 mpath->discovery_retries = 0;
942 mpath->discovery_timeout = disc_timeout_jiff(sdata);
943 }
944 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
945 mpath->flags & MESH_PATH_RESOLVED) {
946 mpath->flags &= ~MESH_PATH_RESOLVING;
947 spin_unlock_bh(&mpath->state_lock);
948 goto enddiscovery;
949 }
950
951 ifmsh->last_preq = jiffies;
952
953 if (time_after(jiffies, ifmsh->last_sn_update +
954 net_traversal_jiffies(sdata)) ||
955 time_before(jiffies, ifmsh->last_sn_update)) {
956 ++ifmsh->sn;
957 sdata->u.mesh.last_sn_update = jiffies;
958 }
959 lifetime = default_lifetime(sdata);
960 ttl = sdata->u.mesh.mshcfg.element_ttl;
961 if (ttl == 0) {
962 sdata->u.mesh.mshstats.dropped_frames_ttl++;
963 spin_unlock_bh(&mpath->state_lock);
964 goto enddiscovery;
965 }
966
967 if (preq_node->flags & PREQ_Q_F_REFRESH)
968 target_flags = MP_F_DO;
969 else
970 target_flags = MP_F_RF;
971
972 spin_unlock_bh(&mpath->state_lock);
973 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
974 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
975 cpu_to_le32(mpath->sn), broadcast_addr, 0,
976 ttl, cpu_to_le32(lifetime), 0,
977 cpu_to_le32(ifmsh->preq_id++), sdata);
978 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
979
980 enddiscovery:
981 rcu_read_unlock();
982 kfree(preq_node);
983 }
984
985 /* mesh_nexthop_resolve - lookup next hop for given skb and start path
986 * discovery if no forwarding information is found.
987 *
988 * @skb: 802.11 frame to be sent
989 * @sdata: network subif the frame will be sent through
990 *
991 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
992 * skb is freeed here if no mpath could be allocated.
993 */
994 int mesh_nexthop_resolve(struct sk_buff *skb,
995 struct ieee80211_sub_if_data *sdata)
996 {
997 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
998 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
999 struct mesh_path *mpath;
1000 struct sk_buff *skb_to_free = NULL;
1001 u8 *target_addr = hdr->addr3;
1002 int err = 0;
1003
1004 rcu_read_lock();
1005 err = mesh_nexthop_lookup(skb, sdata);
1006 if (!err)
1007 goto endlookup;
1008
1009 /* no nexthop found, start resolving */
1010 mpath = mesh_path_lookup(target_addr, sdata);
1011 if (!mpath) {
1012 mesh_path_add(target_addr, sdata);
1013 mpath = mesh_path_lookup(target_addr, sdata);
1014 if (!mpath) {
1015 mesh_path_discard_frame(skb, sdata);
1016 err = -ENOSPC;
1017 goto endlookup;
1018 }
1019 }
1020
1021 if (!(mpath->flags & MESH_PATH_RESOLVING))
1022 mesh_queue_preq(mpath, PREQ_Q_F_START);
1023
1024 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1025 skb_to_free = skb_dequeue(&mpath->frame_queue);
1026
1027 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1028 ieee80211_set_qos_hdr(sdata, skb);
1029 skb_queue_tail(&mpath->frame_queue, skb);
1030 err = -ENOENT;
1031 if (skb_to_free)
1032 mesh_path_discard_frame(skb_to_free, sdata);
1033
1034 endlookup:
1035 rcu_read_unlock();
1036 return err;
1037 }
1038 /**
1039 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1040 * this function is considered "using" the associated mpath, so preempt a path
1041 * refresh if this mpath expires soon.
1042 *
1043 * @skb: 802.11 frame to be sent
1044 * @sdata: network subif the frame will be sent through
1045 *
1046 * Returns: 0 if the next hop was found. Nonzero otherwise.
1047 */
1048 int mesh_nexthop_lookup(struct sk_buff *skb,
1049 struct ieee80211_sub_if_data *sdata)
1050 {
1051 struct mesh_path *mpath;
1052 struct sta_info *next_hop;
1053 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1054 u8 *target_addr = hdr->addr3;
1055 int err = -ENOENT;
1056
1057 rcu_read_lock();
1058 mpath = mesh_path_lookup(target_addr, sdata);
1059
1060 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1061 goto endlookup;
1062
1063 if (time_after(jiffies,
1064 mpath->exp_time -
1065 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1066 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) &&
1067 !(mpath->flags & MESH_PATH_RESOLVING) &&
1068 !(mpath->flags & MESH_PATH_FIXED))
1069 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1070
1071 next_hop = rcu_dereference(mpath->next_hop);
1072 if (next_hop) {
1073 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1074 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1075 err = 0;
1076 }
1077
1078 endlookup:
1079 rcu_read_unlock();
1080 return err;
1081 }
1082
1083 void mesh_path_timer(unsigned long data)
1084 {
1085 struct mesh_path *mpath = (void *) data;
1086 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1087 int ret;
1088
1089 if (sdata->local->quiescing)
1090 return;
1091
1092 spin_lock_bh(&mpath->state_lock);
1093 if (mpath->flags & MESH_PATH_RESOLVED ||
1094 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1095 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1096 spin_unlock_bh(&mpath->state_lock);
1097 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1098 ++mpath->discovery_retries;
1099 mpath->discovery_timeout *= 2;
1100 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1101 spin_unlock_bh(&mpath->state_lock);
1102 mesh_queue_preq(mpath, 0);
1103 } else {
1104 mpath->flags = 0;
1105 mpath->exp_time = jiffies;
1106 spin_unlock_bh(&mpath->state_lock);
1107 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1108 ret = mesh_path_send_to_gates(mpath);
1109 if (ret)
1110 mhwmp_dbg("no gate was reachable");
1111 } else
1112 mesh_path_flush_pending(mpath);
1113 }
1114 }
1115
1116 void
1117 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1118 {
1119 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1120 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1121 u8 flags;
1122
1123 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1124 ? RANN_FLAG_IS_GATE : 0;
1125 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1126 cpu_to_le32(++ifmsh->sn),
1127 0, NULL, 0, broadcast_addr,
1128 0, sdata->u.mesh.mshcfg.element_ttl,
1129 cpu_to_le32(interval), 0, 0, sdata);
1130 }