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[linux-2.6/next.git] / net / mac80211 / mesh_hwmp.c
blob2b18053070c1d45c08b8b9c7f1711f84006134a0
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 "mesh.h"
12
13 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG
14 #define mhwmp_dbg(fmt, args...) printk(KERN_DEBUG "Mesh HWMP: " fmt, ##args)
15 #else
16 #define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0)
17 #endif
18
19 #define TEST_FRAME_LEN 8192
20 #define MAX_METRIC 0xffffffff
21 #define ARITH_SHIFT 8
22
23 /* Number of frames buffered per destination for unresolved destinations */
24 #define MESH_FRAME_QUEUE_LEN 10
25 #define MAX_PREQ_QUEUE_LEN 64
26
27 /* Destination only */
28 #define MP_F_DO 0x1
29 /* Reply and forward */
30 #define MP_F_RF 0x2
31 /* Unknown Sequence Number */
32 #define MP_F_USN 0x01
33 /* Reason code Present */
34 #define MP_F_RCODE 0x02
35
36 static void mesh_queue_preq(struct mesh_path *, u8);
37
38 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
39 {
40 if (ae)
41 offset += 6;
42 return get_unaligned_le32(preq_elem + offset);
43 }
44
45 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
46 {
47 if (ae)
48 offset += 6;
49 return get_unaligned_le16(preq_elem + offset);
50 }
51
52 /* HWMP IE processing macros */
53 #define AE_F (1<<6)
54 #define AE_F_SET(x) (*x & AE_F)
55 #define PREQ_IE_FLAGS(x) (*(x))
56 #define PREQ_IE_HOPCOUNT(x) (*(x + 1))
57 #define PREQ_IE_TTL(x) (*(x + 2))
58 #define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
59 #define PREQ_IE_ORIG_ADDR(x) (x + 7)
60 #define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0);
61 #define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x));
62 #define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x));
63 #define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
64 #define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
65 #define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x));
66
67
68 #define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
69 #define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
70 #define PREP_IE_TTL(x) PREQ_IE_TTL(x)
71 #define PREP_IE_ORIG_ADDR(x) (x + 3)
72 #define PREP_IE_ORIG_SN(x) u32_field_get(x, 9, 0);
73 #define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x));
74 #define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x));
75 #define PREP_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
76 #define PREP_IE_TARGET_SN(x) u32_field_get(x, 27, AE_F_SET(x));
77
78 #define PERR_IE_TTL(x) (*(x))
79 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
80 #define PERR_IE_TARGET_ADDR(x) (x + 3)
81 #define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0);
82 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0);
83
84 #define MSEC_TO_TU(x) (x*1000/1024)
85 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0)
86 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0)
87
88 #define net_traversal_jiffies(s) \
89 msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
90 #define default_lifetime(s) \
91 MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
92 #define min_preq_int_jiff(s) \
93 (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
94 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
95 #define disc_timeout_jiff(s) \
96 msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
97
98 enum mpath_frame_type {
99 MPATH_PREQ = 0,
100 MPATH_PREP,
101 MPATH_PERR,
102 MPATH_RANN
103 };
104
105 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
106
107 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
108 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target,
109 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl,
110 __le32 lifetime, __le32 metric, __le32 preq_id,
111 struct ieee80211_sub_if_data *sdata)
112 {
113 struct ieee80211_local *local = sdata->local;
114 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
115 struct ieee80211_mgmt *mgmt;
116 u8 *pos;
117 int ie_len;
118
119 if (!skb)
120 return -1;
121 skb_reserve(skb, local->hw.extra_tx_headroom);
122 /* 25 is the size of the common mgmt part (24) plus the size of the
123 * common action part (1)
124 */
125 mgmt = (struct ieee80211_mgmt *)
126 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
127 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
128 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
129 IEEE80211_STYPE_ACTION);
130
131 memcpy(mgmt->da, da, ETH_ALEN);
132 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
133 /* BSSID == SA */
134 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
135 mgmt->u.action.category = WLAN_CATEGORY_MESH_PATH_SEL;
136 mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
137
138 switch (action) {
139 case MPATH_PREQ:
140 mhwmp_dbg("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("sending PREP to %pM\n", target);
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("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 break;
161 }
162 *pos++ = ie_len;
163 *pos++ = flags;
164 *pos++ = hop_count;
165 *pos++ = ttl;
166 if (action == MPATH_PREQ) {
167 memcpy(pos, &preq_id, 4);
168 pos += 4;
169 }
170 memcpy(pos, orig_addr, ETH_ALEN);
171 pos += ETH_ALEN;
172 memcpy(pos, &orig_sn, 4);
173 pos += 4;
174 if (action != MPATH_RANN) {
175 memcpy(pos, &lifetime, 4);
176 pos += 4;
177 }
178 memcpy(pos, &metric, 4);
179 pos += 4;
180 if (action == MPATH_PREQ) {
181 /* destination count */
182 *pos++ = 1;
183 *pos++ = target_flags;
184 }
185 if (action != MPATH_RANN) {
186 memcpy(pos, target, ETH_ALEN);
187 pos += ETH_ALEN;
188 memcpy(pos, &target_sn, 4);
189 }
190
191 ieee80211_tx_skb(sdata, skb);
192 return 0;
193 }
194
195 /**
196 * mesh_send_path error - Sends a PERR mesh management frame
197 *
198 * @target: broken destination
199 * @target_sn: SN of the broken destination
200 * @target_rcode: reason code for this PERR
201 * @ra: node this frame is addressed to
202 */
203 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
204 __le16 target_rcode, const u8 *ra,
205 struct ieee80211_sub_if_data *sdata)
206 {
207 struct ieee80211_local *local = sdata->local;
208 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
209 struct ieee80211_mgmt *mgmt;
210 u8 *pos;
211 int ie_len;
212
213 if (!skb)
214 return -1;
215 skb_reserve(skb, local->hw.extra_tx_headroom);
216 /* 25 is the size of the common mgmt part (24) plus the size of the
217 * common action part (1)
218 */
219 mgmt = (struct ieee80211_mgmt *)
220 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
221 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
222 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
223 IEEE80211_STYPE_ACTION);
224
225 memcpy(mgmt->da, ra, ETH_ALEN);
226 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
227 /* BSSID is left zeroed, wildcard value */
228 mgmt->u.action.category = WLAN_CATEGORY_MESH_PATH_SEL;
229 mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
230 ie_len = 15;
231 pos = skb_put(skb, 2 + ie_len);
232 *pos++ = WLAN_EID_PERR;
233 *pos++ = ie_len;
234 /* ttl */
235 *pos++ = ttl;
236 /* number of destinations */
237 *pos++ = 1;
238 /*
239 * flags bit, bit 1 is unset if we know the sequence number and
240 * bit 2 is set if we have a reason code
241 */
242 *pos = 0;
243 if (!target_sn)
244 *pos |= MP_F_USN;
245 if (target_rcode)
246 *pos |= MP_F_RCODE;
247 pos++;
248 memcpy(pos, target, ETH_ALEN);
249 pos += ETH_ALEN;
250 memcpy(pos, &target_sn, 4);
251 pos += 4;
252 memcpy(pos, &target_rcode, 2);
253
254 ieee80211_tx_skb(sdata, skb);
255 return 0;
256 }
257
258 void ieee80211s_update_metric(struct ieee80211_local *local,
259 struct sta_info *stainfo, struct sk_buff *skb)
260 {
261 struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
262 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
263 int failed;
264
265 if (!ieee80211_is_data(hdr->frame_control))
266 return;
267
268 failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
269
270 /* moving average, scaled to 100 */
271 stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
272 if (stainfo->fail_avg > 95)
273 mesh_plink_broken(stainfo);
274 }
275
276 static u32 airtime_link_metric_get(struct ieee80211_local *local,
277 struct sta_info *sta)
278 {
279 struct ieee80211_supported_band *sband;
280 /* This should be adjusted for each device */
281 int device_constant = 1 << ARITH_SHIFT;
282 int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
283 int s_unit = 1 << ARITH_SHIFT;
284 int rate, err;
285 u32 tx_time, estimated_retx;
286 u64 result;
287
288 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
289
290 if (sta->fail_avg >= 100)
291 return MAX_METRIC;
292
293 if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
294 return MAX_METRIC;
295
296 err = (sta->fail_avg << ARITH_SHIFT) / 100;
297
298 /* bitrate is in units of 100 Kbps, while we need rate in units of
299 * 1Mbps. This will be corrected on tx_time computation.
300 */
301 rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
302 tx_time = (device_constant + 10 * test_frame_len / rate);
303 estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
304 result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
305 return (u32)result;
306 }
307
308 /**
309 * hwmp_route_info_get - Update routing info to originator and transmitter
310 *
311 * @sdata: local mesh subif
312 * @mgmt: mesh management frame
313 * @hwmp_ie: hwmp information element (PREP or PREQ)
314 *
315 * This function updates the path routing information to the originator and the
316 * transmitter of a HWMP PREQ or PREP frame.
317 *
318 * Returns: metric to frame originator or 0 if the frame should not be further
319 * processed
320 *
321 * Notes: this function is the only place (besides user-provided info) where
322 * path routing information is updated.
323 */
324 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
325 struct ieee80211_mgmt *mgmt,
326 u8 *hwmp_ie, enum mpath_frame_type action)
327 {
328 struct ieee80211_local *local = sdata->local;
329 struct mesh_path *mpath;
330 struct sta_info *sta;
331 bool fresh_info;
332 u8 *orig_addr, *ta;
333 u32 orig_sn, orig_metric;
334 unsigned long orig_lifetime, exp_time;
335 u32 last_hop_metric, new_metric;
336 bool process = true;
337
338 rcu_read_lock();
339 sta = sta_info_get(sdata, mgmt->sa);
340 if (!sta) {
341 rcu_read_unlock();
342 return 0;
343 }
344
345 last_hop_metric = airtime_link_metric_get(local, sta);
346 /* Update and check originator routing info */
347 fresh_info = true;
348
349 switch (action) {
350 case MPATH_PREQ:
351 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
352 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
353 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
354 orig_metric = PREQ_IE_METRIC(hwmp_ie);
355 break;
356 case MPATH_PREP:
357 /* Originator here refers to the MP that was the destination in
358 * the Path Request. The draft refers to that MP as the
359 * destination address, even though usually it is the origin of
360 * the PREP frame. We divert from the nomenclature in the draft
361 * so that we can easily use a single function to gather path
362 * information from both PREQ and PREP frames.
363 */
364 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
365 orig_sn = PREP_IE_ORIG_SN(hwmp_ie);
366 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
367 orig_metric = PREP_IE_METRIC(hwmp_ie);
368 break;
369 default:
370 rcu_read_unlock();
371 return 0;
372 }
373 new_metric = orig_metric + last_hop_metric;
374 if (new_metric < orig_metric)
375 new_metric = MAX_METRIC;
376 exp_time = TU_TO_EXP_TIME(orig_lifetime);
377
378 if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) {
379 /* This MP is the originator, we are not interested in this
380 * frame, except for updating transmitter's path info.
381 */
382 process = false;
383 fresh_info = false;
384 } else {
385 mpath = mesh_path_lookup(orig_addr, sdata);
386 if (mpath) {
387 spin_lock_bh(&mpath->state_lock);
388 if (mpath->flags & MESH_PATH_FIXED)
389 fresh_info = false;
390 else if ((mpath->flags & MESH_PATH_ACTIVE) &&
391 (mpath->flags & MESH_PATH_SN_VALID)) {
392 if (SN_GT(mpath->sn, orig_sn) ||
393 (mpath->sn == orig_sn &&
394 new_metric >= mpath->metric)) {
395 process = false;
396 fresh_info = false;
397 }
398 }
399 } else {
400 mesh_path_add(orig_addr, sdata);
401 mpath = mesh_path_lookup(orig_addr, sdata);
402 if (!mpath) {
403 rcu_read_unlock();
404 return 0;
405 }
406 spin_lock_bh(&mpath->state_lock);
407 }
408
409 if (fresh_info) {
410 mesh_path_assign_nexthop(mpath, sta);
411 mpath->flags |= MESH_PATH_SN_VALID;
412 mpath->metric = new_metric;
413 mpath->sn = orig_sn;
414 mpath->exp_time = time_after(mpath->exp_time, exp_time)
415 ? mpath->exp_time : exp_time;
416 mesh_path_activate(mpath);
417 spin_unlock_bh(&mpath->state_lock);
418 mesh_path_tx_pending(mpath);
419 /* draft says preq_id should be saved to, but there does
420 * not seem to be any use for it, skipping by now
421 */
422 } else
423 spin_unlock_bh(&mpath->state_lock);
424 }
425
426 /* Update and check transmitter routing info */
427 ta = mgmt->sa;
428 if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
429 fresh_info = false;
430 else {
431 fresh_info = true;
432
433 mpath = mesh_path_lookup(ta, sdata);
434 if (mpath) {
435 spin_lock_bh(&mpath->state_lock);
436 if ((mpath->flags & MESH_PATH_FIXED) ||
437 ((mpath->flags & MESH_PATH_ACTIVE) &&
438 (last_hop_metric > mpath->metric)))
439 fresh_info = false;
440 } else {
441 mesh_path_add(ta, sdata);
442 mpath = mesh_path_lookup(ta, sdata);
443 if (!mpath) {
444 rcu_read_unlock();
445 return 0;
446 }
447 spin_lock_bh(&mpath->state_lock);
448 }
449
450 if (fresh_info) {
451 mesh_path_assign_nexthop(mpath, sta);
452 mpath->flags &= ~MESH_PATH_SN_VALID;
453 mpath->metric = last_hop_metric;
454 mpath->exp_time = time_after(mpath->exp_time, exp_time)
455 ? mpath->exp_time : exp_time;
456 mesh_path_activate(mpath);
457 spin_unlock_bh(&mpath->state_lock);
458 mesh_path_tx_pending(mpath);
459 } else
460 spin_unlock_bh(&mpath->state_lock);
461 }
462
463 rcu_read_unlock();
464
465 return process ? new_metric : 0;
466 }
467
468 static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
469 struct ieee80211_mgmt *mgmt,
470 u8 *preq_elem, u32 metric)
471 {
472 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
473 struct mesh_path *mpath;
474 u8 *target_addr, *orig_addr;
475 u8 target_flags, ttl;
476 u32 orig_sn, target_sn, lifetime;
477 bool reply = false;
478 bool forward = true;
479
480 /* Update target SN, if present */
481 target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
482 orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
483 target_sn = PREQ_IE_TARGET_SN(preq_elem);
484 orig_sn = PREQ_IE_ORIG_SN(preq_elem);
485 target_flags = PREQ_IE_TARGET_F(preq_elem);
486
487 mhwmp_dbg("received PREQ from %pM\n", orig_addr);
488
489 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) {
490 mhwmp_dbg("PREQ is for us\n");
491 forward = false;
492 reply = true;
493 metric = 0;
494 if (time_after(jiffies, ifmsh->last_sn_update +
495 net_traversal_jiffies(sdata)) ||
496 time_before(jiffies, ifmsh->last_sn_update)) {
497 target_sn = ++ifmsh->sn;
498 ifmsh->last_sn_update = jiffies;
499 }
500 } else {
501 rcu_read_lock();
502 mpath = mesh_path_lookup(target_addr, sdata);
503 if (mpath) {
504 if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
505 SN_LT(mpath->sn, target_sn)) {
506 mpath->sn = target_sn;
507 mpath->flags |= MESH_PATH_SN_VALID;
508 } else if ((!(target_flags & MP_F_DO)) &&
509 (mpath->flags & MESH_PATH_ACTIVE)) {
510 reply = true;
511 metric = mpath->metric;
512 target_sn = mpath->sn;
513 if (target_flags & MP_F_RF)
514 target_flags |= MP_F_DO;
515 else
516 forward = false;
517 }
518 }
519 rcu_read_unlock();
520 }
521
522 if (reply) {
523 lifetime = PREQ_IE_LIFETIME(preq_elem);
524 ttl = ifmsh->mshcfg.element_ttl;
525 if (ttl != 0) {
526 mhwmp_dbg("replying to the PREQ\n");
527 mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr,
528 cpu_to_le32(target_sn), 0, orig_addr,
529 cpu_to_le32(orig_sn), mgmt->sa, 0, ttl,
530 cpu_to_le32(lifetime), cpu_to_le32(metric),
531 0, sdata);
532 } else
533 ifmsh->mshstats.dropped_frames_ttl++;
534 }
535
536 if (forward) {
537 u32 preq_id;
538 u8 hopcount, flags;
539
540 ttl = PREQ_IE_TTL(preq_elem);
541 lifetime = PREQ_IE_LIFETIME(preq_elem);
542 if (ttl <= 1) {
543 ifmsh->mshstats.dropped_frames_ttl++;
544 return;
545 }
546 mhwmp_dbg("forwarding the PREQ from %pM\n", orig_addr);
547 --ttl;
548 flags = PREQ_IE_FLAGS(preq_elem);
549 preq_id = PREQ_IE_PREQ_ID(preq_elem);
550 hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
551 mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
552 cpu_to_le32(orig_sn), target_flags, target_addr,
553 cpu_to_le32(target_sn), broadcast_addr,
554 hopcount, ttl, cpu_to_le32(lifetime),
555 cpu_to_le32(metric), cpu_to_le32(preq_id),
556 sdata);
557 ifmsh->mshstats.fwded_mcast++;
558 ifmsh->mshstats.fwded_frames++;
559 }
560 }
561
562
563 static inline struct sta_info *
564 next_hop_deref_protected(struct mesh_path *mpath)
565 {
566 return rcu_dereference_protected(mpath->next_hop,
567 lockdep_is_held(&mpath->state_lock));
568 }
569
570
571 static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
572 struct ieee80211_mgmt *mgmt,
573 u8 *prep_elem, u32 metric)
574 {
575 struct mesh_path *mpath;
576 u8 *target_addr, *orig_addr;
577 u8 ttl, hopcount, flags;
578 u8 next_hop[ETH_ALEN];
579 u32 target_sn, orig_sn, lifetime;
580
581 mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem));
582
583 /* Note that we divert from the draft nomenclature and denominate
584 * destination to what the draft refers to as origininator. So in this
585 * function destnation refers to the final destination of the PREP,
586 * which corresponds with the originator of the PREQ which this PREP
587 * replies
588 */
589 target_addr = PREP_IE_TARGET_ADDR(prep_elem);
590 if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0)
591 /* destination, no forwarding required */
592 return;
593
594 ttl = PREP_IE_TTL(prep_elem);
595 if (ttl <= 1) {
596 sdata->u.mesh.mshstats.dropped_frames_ttl++;
597 return;
598 }
599
600 rcu_read_lock();
601 mpath = mesh_path_lookup(target_addr, sdata);
602 if (mpath)
603 spin_lock_bh(&mpath->state_lock);
604 else
605 goto fail;
606 if (!(mpath->flags & MESH_PATH_ACTIVE)) {
607 spin_unlock_bh(&mpath->state_lock);
608 goto fail;
609 }
610 memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
611 spin_unlock_bh(&mpath->state_lock);
612 --ttl;
613 flags = PREP_IE_FLAGS(prep_elem);
614 lifetime = PREP_IE_LIFETIME(prep_elem);
615 hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
616 orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
617 target_sn = PREP_IE_TARGET_SN(prep_elem);
618 orig_sn = PREP_IE_ORIG_SN(prep_elem);
619
620 mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
621 cpu_to_le32(orig_sn), 0, target_addr,
622 cpu_to_le32(target_sn), next_hop, hopcount,
623 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
624 0, sdata);
625 rcu_read_unlock();
626
627 sdata->u.mesh.mshstats.fwded_unicast++;
628 sdata->u.mesh.mshstats.fwded_frames++;
629 return;
630
631 fail:
632 rcu_read_unlock();
633 sdata->u.mesh.mshstats.dropped_frames_no_route++;
634 }
635
636 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
637 struct ieee80211_mgmt *mgmt, u8 *perr_elem)
638 {
639 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
640 struct mesh_path *mpath;
641 u8 ttl;
642 u8 *ta, *target_addr;
643 u32 target_sn;
644 u16 target_rcode;
645
646 ta = mgmt->sa;
647 ttl = PERR_IE_TTL(perr_elem);
648 if (ttl <= 1) {
649 ifmsh->mshstats.dropped_frames_ttl++;
650 return;
651 }
652 ttl--;
653 target_addr = PERR_IE_TARGET_ADDR(perr_elem);
654 target_sn = PERR_IE_TARGET_SN(perr_elem);
655 target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
656
657 rcu_read_lock();
658 mpath = mesh_path_lookup(target_addr, sdata);
659 if (mpath) {
660 spin_lock_bh(&mpath->state_lock);
661 if (mpath->flags & MESH_PATH_ACTIVE &&
662 memcmp(ta, next_hop_deref_protected(mpath)->sta.addr,
663 ETH_ALEN) == 0 &&
664 (!(mpath->flags & MESH_PATH_SN_VALID) ||
665 SN_GT(target_sn, mpath->sn))) {
666 mpath->flags &= ~MESH_PATH_ACTIVE;
667 mpath->sn = target_sn;
668 spin_unlock_bh(&mpath->state_lock);
669 mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
670 cpu_to_le16(target_rcode),
671 broadcast_addr, sdata);
672 } else
673 spin_unlock_bh(&mpath->state_lock);
674 }
675 rcu_read_unlock();
676 }
677
678 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
679 struct ieee80211_mgmt *mgmt,
680 struct ieee80211_rann_ie *rann)
681 {
682 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
683 struct mesh_path *mpath;
684 u8 ttl, flags, hopcount;
685 u8 *orig_addr;
686 u32 orig_sn, metric;
687
688 ttl = rann->rann_ttl;
689 if (ttl <= 1) {
690 ifmsh->mshstats.dropped_frames_ttl++;
691 return;
692 }
693 ttl--;
694 flags = rann->rann_flags;
695 orig_addr = rann->rann_addr;
696 orig_sn = rann->rann_seq;
697 hopcount = rann->rann_hopcount;
698 hopcount++;
699 metric = rann->rann_metric;
700 mhwmp_dbg("received RANN from %pM\n", orig_addr);
701
702 rcu_read_lock();
703 mpath = mesh_path_lookup(orig_addr, sdata);
704 if (!mpath) {
705 mesh_path_add(orig_addr, sdata);
706 mpath = mesh_path_lookup(orig_addr, sdata);
707 if (!mpath) {
708 rcu_read_unlock();
709 sdata->u.mesh.mshstats.dropped_frames_no_route++;
710 return;
711 }
712 mesh_queue_preq(mpath,
713 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
714 }
715 if (mpath->sn < orig_sn) {
716 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
717 cpu_to_le32(orig_sn),
718 0, NULL, 0, broadcast_addr,
719 hopcount, ttl, 0,
720 cpu_to_le32(metric + mpath->metric),
721 0, sdata);
722 mpath->sn = orig_sn;
723 }
724 rcu_read_unlock();
725 }
726
727
728 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
729 struct ieee80211_mgmt *mgmt,
730 size_t len)
731 {
732 struct ieee802_11_elems elems;
733 size_t baselen;
734 u32 last_hop_metric;
735
736 /* need action_code */
737 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
738 return;
739
740 baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
741 ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
742 len - baselen, &elems);
743
744 if (elems.preq) {
745 if (elems.preq_len != 37)
746 /* Right now we support just 1 destination and no AE */
747 return;
748 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
749 MPATH_PREQ);
750 if (last_hop_metric)
751 hwmp_preq_frame_process(sdata, mgmt, elems.preq,
752 last_hop_metric);
753 }
754 if (elems.prep) {
755 if (elems.prep_len != 31)
756 /* Right now we support no AE */
757 return;
758 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
759 MPATH_PREP);
760 if (last_hop_metric)
761 hwmp_prep_frame_process(sdata, mgmt, elems.prep,
762 last_hop_metric);
763 }
764 if (elems.perr) {
765 if (elems.perr_len != 15)
766 /* Right now we support only one destination per PERR */
767 return;
768 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
769 }
770 if (elems.rann)
771 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
772 }
773
774 /**
775 * mesh_queue_preq - queue a PREQ to a given destination
776 *
777 * @mpath: mesh path to discover
778 * @flags: special attributes of the PREQ to be sent
779 *
780 * Locking: the function must be called from within a rcu read lock block.
781 *
782 */
783 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
784 {
785 struct ieee80211_sub_if_data *sdata = mpath->sdata;
786 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
787 struct mesh_preq_queue *preq_node;
788
789 preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
790 if (!preq_node) {
791 mhwmp_dbg("could not allocate PREQ node\n");
792 return;
793 }
794
795 spin_lock(&ifmsh->mesh_preq_queue_lock);
796 if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
797 spin_unlock(&ifmsh->mesh_preq_queue_lock);
798 kfree(preq_node);
799 if (printk_ratelimit())
800 mhwmp_dbg("PREQ node queue full\n");
801 return;
802 }
803
804 memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
805 preq_node->flags = flags;
806
807 list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
808 ++ifmsh->preq_queue_len;
809 spin_unlock(&ifmsh->mesh_preq_queue_lock);
810
811 if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
812 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
813
814 else if (time_before(jiffies, ifmsh->last_preq)) {
815 /* avoid long wait if did not send preqs for a long time
816 * and jiffies wrapped around
817 */
818 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
819 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
820 } else
821 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
822 min_preq_int_jiff(sdata));
823 }
824
825 /**
826 * mesh_path_start_discovery - launch a path discovery from the PREQ queue
827 *
828 * @sdata: local mesh subif
829 */
830 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
831 {
832 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
833 struct mesh_preq_queue *preq_node;
834 struct mesh_path *mpath;
835 u8 ttl, target_flags;
836 u32 lifetime;
837
838 spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
839 if (!ifmsh->preq_queue_len ||
840 time_before(jiffies, ifmsh->last_preq +
841 min_preq_int_jiff(sdata))) {
842 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
843 return;
844 }
845
846 preq_node = list_first_entry(&ifmsh->preq_queue.list,
847 struct mesh_preq_queue, list);
848 list_del(&preq_node->list);
849 --ifmsh->preq_queue_len;
850 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
851
852 rcu_read_lock();
853 mpath = mesh_path_lookup(preq_node->dst, sdata);
854 if (!mpath)
855 goto enddiscovery;
856
857 spin_lock_bh(&mpath->state_lock);
858 if (preq_node->flags & PREQ_Q_F_START) {
859 if (mpath->flags & MESH_PATH_RESOLVING) {
860 spin_unlock_bh(&mpath->state_lock);
861 goto enddiscovery;
862 } else {
863 mpath->flags &= ~MESH_PATH_RESOLVED;
864 mpath->flags |= MESH_PATH_RESOLVING;
865 mpath->discovery_retries = 0;
866 mpath->discovery_timeout = disc_timeout_jiff(sdata);
867 }
868 } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
869 mpath->flags & MESH_PATH_RESOLVED) {
870 mpath->flags &= ~MESH_PATH_RESOLVING;
871 spin_unlock_bh(&mpath->state_lock);
872 goto enddiscovery;
873 }
874
875 ifmsh->last_preq = jiffies;
876
877 if (time_after(jiffies, ifmsh->last_sn_update +
878 net_traversal_jiffies(sdata)) ||
879 time_before(jiffies, ifmsh->last_sn_update)) {
880 ++ifmsh->sn;
881 sdata->u.mesh.last_sn_update = jiffies;
882 }
883 lifetime = default_lifetime(sdata);
884 ttl = sdata->u.mesh.mshcfg.element_ttl;
885 if (ttl == 0) {
886 sdata->u.mesh.mshstats.dropped_frames_ttl++;
887 spin_unlock_bh(&mpath->state_lock);
888 goto enddiscovery;
889 }
890
891 if (preq_node->flags & PREQ_Q_F_REFRESH)
892 target_flags = MP_F_DO;
893 else
894 target_flags = MP_F_RF;
895
896 spin_unlock_bh(&mpath->state_lock);
897 mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
898 cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
899 cpu_to_le32(mpath->sn), broadcast_addr, 0,
900 ttl, cpu_to_le32(lifetime), 0,
901 cpu_to_le32(ifmsh->preq_id++), sdata);
902 mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
903
904 enddiscovery:
905 rcu_read_unlock();
906 kfree(preq_node);
907 }
908
909 /**
910 * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
911 *
912 * @skb: 802.11 frame to be sent
913 * @sdata: network subif the frame will be sent through
914 *
915 * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
916 * found, the function will start a path discovery and queue the frame so it is
917 * sent when the path is resolved. This means the caller must not free the skb
918 * in this case.
919 */
920 int mesh_nexthop_lookup(struct sk_buff *skb,
921 struct ieee80211_sub_if_data *sdata)
922 {
923 struct sk_buff *skb_to_free = NULL;
924 struct mesh_path *mpath;
925 struct sta_info *next_hop;
926 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
927 u8 *target_addr = hdr->addr3;
928 int err = 0;
929
930 rcu_read_lock();
931 mpath = mesh_path_lookup(target_addr, sdata);
932
933 if (!mpath) {
934 mesh_path_add(target_addr, sdata);
935 mpath = mesh_path_lookup(target_addr, sdata);
936 if (!mpath) {
937 sdata->u.mesh.mshstats.dropped_frames_no_route++;
938 err = -ENOSPC;
939 goto endlookup;
940 }
941 }
942
943 if (mpath->flags & MESH_PATH_ACTIVE) {
944 if (time_after(jiffies,
945 mpath->exp_time -
946 msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
947 !memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) &&
948 !(mpath->flags & MESH_PATH_RESOLVING) &&
949 !(mpath->flags & MESH_PATH_FIXED)) {
950 mesh_queue_preq(mpath,
951 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
952 }
953 next_hop = rcu_dereference(mpath->next_hop);
954 if (next_hop)
955 memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
956 else
957 err = -ENOENT;
958 } else {
959 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
960 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
961 /* Start discovery only if it is not running yet */
962 mesh_queue_preq(mpath, PREQ_Q_F_START);
963 }
964
965 if (skb_queue_len(&mpath->frame_queue) >=
966 MESH_FRAME_QUEUE_LEN)
967 skb_to_free = skb_dequeue(&mpath->frame_queue);
968
969 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
970 skb_queue_tail(&mpath->frame_queue, skb);
971 if (skb_to_free)
972 mesh_path_discard_frame(skb_to_free, sdata);
973 err = -ENOENT;
974 }
975
976 endlookup:
977 rcu_read_unlock();
978 return err;
979 }
980
981 void mesh_path_timer(unsigned long data)
982 {
983 struct mesh_path *mpath = (void *) data;
984 struct ieee80211_sub_if_data *sdata = mpath->sdata;
985
986 if (sdata->local->quiescing)
987 return;
988
989 spin_lock_bh(&mpath->state_lock);
990 if (mpath->flags & MESH_PATH_RESOLVED ||
991 (!(mpath->flags & MESH_PATH_RESOLVING)))
992 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
993 else if (mpath->discovery_retries < max_preq_retries(sdata)) {
994 ++mpath->discovery_retries;
995 mpath->discovery_timeout *= 2;
996 mesh_queue_preq(mpath, 0);
997 } else {
998 mpath->flags = 0;
999 mpath->exp_time = jiffies;
1000 mesh_path_flush_pending(mpath);
1001 }
1002
1003 spin_unlock_bh(&mpath->state_lock);
1004 }
1005
1006 void
1007 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1008 {
1009 struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1010
1011 mesh_path_sel_frame_tx(MPATH_RANN, 0, sdata->vif.addr,
1012 cpu_to_le32(++ifmsh->sn),
1013 0, NULL, 0, broadcast_addr,
1014 0, sdata->u.mesh.mshcfg.element_ttl,
1015 0, 0, 0, sdata);
1016 }
linux-next