?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ixgbe: Correct Adaptive Interrupt Moderation so that it will change values
[linux-2.6.git] / net / mac80211 / mesh_hwmp.c
blob1c6f3d02aebf5a4f19630f604aae94cda6810247
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) ((long) (y) - (long) (x) < 0)
90 #define SN_LT(x, y) ((long) (x) - (long) (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 mesh_path *mpath;
736 u8 ttl, flags, hopcount;
737 u8 *orig_addr;
738 u32 orig_sn, metric;
739 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
740 bool root_is_gate;
741
742 ttl = rann->rann_ttl;
743 if (ttl <= 1) {
744 ifmsh->mshstats.dropped_frames_ttl++;
745 return;
746 }
747 ttl--;
748 flags = rann->rann_flags;
749 root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
750 orig_addr = rann->rann_addr;
751 orig_sn = rann->rann_seq;
752 hopcount = rann->rann_hopcount;
753 hopcount++;
754 metric = rann->rann_metric;
755
756 /* Ignore our own RANNs */
757 if (compare_ether_addr(orig_addr, sdata->vif.addr) == 0)
758 return;
759
760 mhwmp_dbg("received RANN from %pM via neighbour %pM (is_gate=%d)",
761 orig_addr, mgmt->sa, root_is_gate);
762
763 rcu_read_lock();
764 mpath = mesh_path_lookup(orig_addr, sdata);
765 if (!mpath) {
766 mesh_path_add(orig_addr, sdata);
767 mpath = mesh_path_lookup(orig_addr, sdata);
768 if (!mpath) {
769 rcu_read_unlock();
770 sdata->u.mesh.mshstats.dropped_frames_no_route++;
771 return;
772 }
773 }
774
775 if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
776 time_after(jiffies, mpath->exp_time - 1*HZ)) &&
777 !(mpath->flags & MESH_PATH_FIXED)) {
778 mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
779 orig_addr);
780 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
781 }
782
783 if (mpath->sn < orig_sn && ifmsh->mshcfg.dot11MeshForwarding) {
784 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
785 cpu_to_le32(orig_sn),
786 0, NULL, 0, broadcast_addr,
787 hopcount, ttl, cpu_to_le32(interval),
788 cpu_to_le32(metric + mpath->metric),
789 0, sdata);
790 mpath->sn = orig_sn;
791 }
792
793 /* Using individually addressed PREQ for root node */
794 memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
795 mpath->is_root = true;
796
797 if (root_is_gate)
798 mesh_path_add_gate(mpath);
799
800 rcu_read_unlock();
801 }
802
803
804 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
805 struct ieee80211_mgmt *mgmt,
806 size_t len)
807 {
808 struct ieee802_11_elems elems;
809 size_t baselen;
810 u32 last_hop_metric;
811 struct sta_info *sta;
812
813 /* need action_code */
814 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
815 return;
816
817 rcu_read_lock();
818 sta = sta_info_get(sdata, mgmt->sa);
819 if (!sta || sta->plink_state != NL80211_PLINK_ESTAB) {
820 rcu_read_unlock();
821 return;
822 }
823 rcu_read_unlock();
824
825 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
826 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
827 len - baselen, &elems);
828
829 if (elems.preq) {
830 if (elems.preq_len != 37)
831 /* Right now we support just 1 destination and no AE */
832 return;
833 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
834 MPATH_PREQ);
835 if (last_hop_metric)
836 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
837 last_hop_metric);
838 }
839 if (elems.prep) {
840 if (elems.prep_len != 31)
841 /* Right now we support no AE */
842 return;
843 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
844 MPATH_PREP);
845 if (last_hop_metric)
846 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
847 last_hop_metric);
848 }
849 if (elems.perr) {
850 if (elems.perr_len != 15)
851 /* Right now we support only one destination per PERR */
852 return;
853 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
854 }
855 if (elems.rann)
856 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
857 }
858
859 /**
860 * mesh_queue_preq - queue a PREQ to a given destination
861 *
862 * @mpath: mesh path to discover
863 * @flags: special attributes of the PREQ to be sent
864 *
865 * Locking: the function must be called from within a rcu read lock block.
866 *
867 */
868 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
869 {
870 struct ieee80211_sub_if_data *sdata = mpath->sdata;
871 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
872 struct mesh_preq_queue *preq_node;
873
874 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
875 if (!preq_node) {
876 mhwmp_dbg("could not allocate PREQ node");
877 return;
878 }
879
880 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
881 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
882 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
883 kfree(preq_node);
884 if (printk_ratelimit())
885 mhwmp_dbg("PREQ node queue full");
886 return;
887 }
888
889 spin_lock(&mpath->state_lock);
890 if (mpath->flags & MESH_PATH_REQ_QUEUED) {
891 spin_unlock(&mpath->state_lock);
892 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
893 kfree(preq_node);
894 return;
895 }
896
897 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
898 preq_node->flags = flags;
899
900 mpath->flags |= MESH_PATH_REQ_QUEUED;
901 spin_unlock(&mpath->state_lock);
902
903 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
904 ++ifmsh->preq_queue_len;
905 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
906
907 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
908 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
909
910 else if (time_before(jiffies, ifmsh->last_preq)) {
911 /* avoid long wait if did not send preqs for a long time
912 * and jiffies wrapped around
913 */
914 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
915 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
916 } else
917 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
918 min_preq_int_jiff(sdata));
919 }
920
921 /**
922 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
923 *
924 * @sdata: local mesh subif
925 */
926 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
927 {
928 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
929 struct mesh_preq_queue *preq_node;
930 struct mesh_path *mpath;
931 u8 ttl, target_flags;
932 const u8 *da;
933 u32 lifetime;
934
935 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
936 if (!ifmsh->preq_queue_len ||
937 time_before(jiffies, ifmsh->last_preq +
938 min_preq_int_jiff(sdata))) {
939 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
940 return;
941 }
942
943 preq_node = list_first_entry(&ifmsh->preq_queue.list,
944 struct mesh_preq_queue, list);
945 list_del(&preq_node->list);
946 --ifmsh->preq_queue_len;
947 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
948
949 rcu_read_lock();
950 mpath = mesh_path_lookup(preq_node->dst, sdata);
951 if (!mpath)
952 goto enddiscovery;
953
954 spin_lock_bh(&mpath->state_lock);
955 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
956 if (preq_node->flags & PREQ_Q_F_START) {
957 if (mpath->flags & MESH_PATH_RESOLVING) {
958 spin_unlock_bh(&mpath->state_lock);
959 goto enddiscovery;
960 } else {
961 mpath->flags &= ~MESH_PATH_RESOLVED;
962 mpath->flags |= MESH_PATH_RESOLVING;
963 mpath->discovery_retries = 0;
964 mpath->discovery_timeout = disc_timeout_jiff(sdata);
965 }
966 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
967 mpath->flags & MESH_PATH_RESOLVED) {
968 mpath->flags &= ~MESH_PATH_RESOLVING;
969 spin_unlock_bh(&mpath->state_lock);
970 goto enddiscovery;
971 }
972
973 ifmsh->last_preq = jiffies;
974
975 if (time_after(jiffies, ifmsh->last_sn_update +
976 net_traversal_jiffies(sdata)) ||
977 time_before(jiffies, ifmsh->last_sn_update)) {
978 ++ifmsh->sn;
979 sdata->u.mesh.last_sn_update = jiffies;
980 }
981 lifetime = default_lifetime(sdata);
982 ttl = sdata->u.mesh.mshcfg.element_ttl;
983 if (ttl == 0) {
984 sdata->u.mesh.mshstats.dropped_frames_ttl++;
985 spin_unlock_bh(&mpath->state_lock);
986 goto enddiscovery;
987 }
988
989 if (preq_node->flags & PREQ_Q_F_REFRESH)
990 target_flags = MP_F_DO;
991 else
992 target_flags = MP_F_RF;
993
994 spin_unlock_bh(&mpath->state_lock);
995 da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
996 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
997 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
998 cpu_to_le32(mpath->sn), da, 0,
999 ttl, cpu_to_le32(lifetime), 0,
1000 cpu_to_le32(ifmsh->preq_id++), sdata);
1001 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
1002
1003 enddiscovery:
1004 rcu_read_unlock();
1005 kfree(preq_node);
1006 }
1007
1008 /* mesh_nexthop_resolve - lookup next hop for given skb and start path
1009 * discovery if no forwarding information is found.
1010 *
1011 * @skb: 802.11 frame to be sent
1012 * @sdata: network subif the frame will be sent through
1013 *
1014 * Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
1015 * skb is freeed here if no mpath could be allocated.
1016 */
1017 int mesh_nexthop_resolve(struct sk_buff *skb,
1018 struct ieee80211_sub_if_data *sdata)
1019 {
1020 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1021 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1022 struct mesh_path *mpath;
1023 struct sk_buff *skb_to_free = NULL;
1024 u8 *target_addr = hdr->addr3;
1025 int err = 0;
1026
1027 rcu_read_lock();
1028 err = mesh_nexthop_lookup(skb, sdata);
1029 if (!err)
1030 goto endlookup;
1031
1032 /* no nexthop found, start resolving */
1033 mpath = mesh_path_lookup(target_addr, sdata);
1034 if (!mpath) {
1035 mesh_path_add(target_addr, sdata);
1036 mpath = mesh_path_lookup(target_addr, sdata);
1037 if (!mpath) {
1038 mesh_path_discard_frame(skb, sdata);
1039 err = -ENOSPC;
1040 goto endlookup;
1041 }
1042 }
1043
1044 if (!(mpath->flags & MESH_PATH_RESOLVING))
1045 mesh_queue_preq(mpath, PREQ_Q_F_START);
1046
1047 if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
1048 skb_to_free = skb_dequeue(&mpath->frame_queue);
1049
1050 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1051 ieee80211_set_qos_hdr(sdata, skb);
1052 skb_queue_tail(&mpath->frame_queue, skb);
1053 err = -ENOENT;
1054 if (skb_to_free)
1055 mesh_path_discard_frame(skb_to_free, sdata);
1056
1057 endlookup:
1058 rcu_read_unlock();
1059 return err;
1060 }
1061 /**
1062 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
1063 * this function is considered "using" the associated mpath, so preempt a path
1064 * refresh if this mpath expires soon.
1065 *
1066 * @skb: 802.11 frame to be sent
1067 * @sdata: network subif the frame will be sent through
1068 *
1069 * Returns: 0 if the next hop was found. Nonzero otherwise.
1070 */
1071 int mesh_nexthop_lookup(struct sk_buff *skb,
1072 struct ieee80211_sub_if_data *sdata)
1073 {
1074 struct mesh_path *mpath;
1075 struct sta_info *next_hop;
1076 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1077 u8 *target_addr = hdr->addr3;
1078 int err = -ENOENT;
1079
1080 rcu_read_lock();
1081 mpath = mesh_path_lookup(target_addr, sdata);
1082
1083 if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
1084 goto endlookup;
1085
1086 if (time_after(jiffies,
1087 mpath->exp_time -
1088 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
1089 !compare_ether_addr(sdata->vif.addr, hdr->addr4) &&
1090 !(mpath->flags & MESH_PATH_RESOLVING) &&
1091 !(mpath->flags & MESH_PATH_FIXED))
1092 mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
1093
1094 next_hop = rcu_dereference(mpath->next_hop);
1095 if (next_hop) {
1096 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
1097 memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
1098 err = 0;
1099 }
1100
1101 endlookup:
1102 rcu_read_unlock();
1103 return err;
1104 }
1105
1106 void mesh_path_timer(unsigned long data)
1107 {
1108 struct mesh_path *mpath = (void *) data;
1109 struct ieee80211_sub_if_data *sdata = mpath->sdata;
1110 int ret;
1111
1112 if (sdata->local->quiescing)
1113 return;
1114
1115 spin_lock_bh(&mpath->state_lock);
1116 if (mpath->flags & MESH_PATH_RESOLVED ||
1117 (!(mpath->flags & MESH_PATH_RESOLVING))) {
1118 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
1119 spin_unlock_bh(&mpath->state_lock);
1120 } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
1121 ++mpath->discovery_retries;
1122 mpath->discovery_timeout *= 2;
1123 mpath->flags &= ~MESH_PATH_REQ_QUEUED;
1124 spin_unlock_bh(&mpath->state_lock);
1125 mesh_queue_preq(mpath, 0);
1126 } else {
1127 mpath->flags = 0;
1128 mpath->exp_time = jiffies;
1129 spin_unlock_bh(&mpath->state_lock);
1130 if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
1131 ret = mesh_path_send_to_gates(mpath);
1132 if (ret)
1133 mhwmp_dbg("no gate was reachable");
1134 } else
1135 mesh_path_flush_pending(mpath);
1136 }
1137 }
1138
1139 void
1140 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1141 {
1142 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1143 u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
1144 u8 flags;
1145
1146 flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
1147 ? RANN_FLAG_IS_GATE : 0;
1148 mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
1149 cpu_to_le32(++ifmsh->sn),
1150 0, NULL, 0, broadcast_addr,
1151 0, sdata->u.mesh.mshcfg.element_ttl,
1152 cpu_to_le32(interval), 0, 0, sdata);
1153 }
Linus' kernel tree