net: Move && and || to end of previous line
[linux-2.6.git] / net / mac80211 / mesh_hwmp.c
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9
10 #include "mesh.h"
11
12 #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG
13 #define mhwmp_dbg(fmt, args...)   printk(KERN_DEBUG "Mesh HWMP: " fmt, ##args)
14 #else
15 #define mhwmp_dbg(fmt, args...)   do { (void)(0); } while (0)
16 #endif
17
18 #define TEST_FRAME_LEN  8192
19 #define MAX_METRIC      0xffffffff
20 #define ARITH_SHIFT     8
21
22 /* Number of frames buffered per destination for unresolved destinations */
23 #define MESH_FRAME_QUEUE_LEN    10
24 #define MAX_PREQ_QUEUE_LEN      64
25
26 /* Destination only */
27 #define MP_F_DO 0x1
28 /* Reply and forward */
29 #define MP_F_RF 0x2
30 /* Unknown Sequence Number */
31 #define MP_F_USN    0x01
32 /* Reason code Present */
33 #define MP_F_RCODE  0x02
34
35 static void mesh_queue_preq(struct mesh_path *, u8);
36
37 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
38 {
39         if (ae)
40                 offset += 6;
41         return get_unaligned_le32(preq_elem + offset);
42 }
43
44 static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
45 {
46         if (ae)
47                 offset += 6;
48         return get_unaligned_le16(preq_elem + offset);
49 }
50
51 /* HWMP IE processing macros */
52 #define AE_F                    (1<<6)
53 #define AE_F_SET(x)             (*x & AE_F)
54 #define PREQ_IE_FLAGS(x)        (*(x))
55 #define PREQ_IE_HOPCOUNT(x)     (*(x + 1))
56 #define PREQ_IE_TTL(x)          (*(x + 2))
57 #define PREQ_IE_PREQ_ID(x)      u32_field_get(x, 3, 0)
58 #define PREQ_IE_ORIG_ADDR(x)    (x + 7)
59 #define PREQ_IE_ORIG_SN(x)      u32_field_get(x, 13, 0);
60 #define PREQ_IE_LIFETIME(x)     u32_field_get(x, 17, AE_F_SET(x));
61 #define PREQ_IE_METRIC(x)       u32_field_get(x, 21, AE_F_SET(x));
62 #define PREQ_IE_TARGET_F(x)     (*(AE_F_SET(x) ? x + 32 : x + 26))
63 #define PREQ_IE_TARGET_ADDR(x)  (AE_F_SET(x) ? x + 33 : x + 27)
64 #define PREQ_IE_TARGET_SN(x)    u32_field_get(x, 33, AE_F_SET(x));
65
66
67 #define PREP_IE_FLAGS(x)        PREQ_IE_FLAGS(x)
68 #define PREP_IE_HOPCOUNT(x)     PREQ_IE_HOPCOUNT(x)
69 #define PREP_IE_TTL(x)          PREQ_IE_TTL(x)
70 #define PREP_IE_ORIG_ADDR(x)    (x + 3)
71 #define PREP_IE_ORIG_SN(x)      u32_field_get(x, 9, 0);
72 #define PREP_IE_LIFETIME(x)     u32_field_get(x, 13, AE_F_SET(x));
73 #define PREP_IE_METRIC(x)       u32_field_get(x, 17, AE_F_SET(x));
74 #define PREP_IE_TARGET_ADDR(x)  (AE_F_SET(x) ? x + 27 : x + 21)
75 #define PREP_IE_TARGET_SN(x)    u32_field_get(x, 27, AE_F_SET(x));
76
77 #define PERR_IE_TTL(x)          (*(x))
78 #define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
79 #define PERR_IE_TARGET_ADDR(x)  (x + 3)
80 #define PERR_IE_TARGET_SN(x)    u32_field_get(x, 9, 0);
81 #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0);
82
83 #define MSEC_TO_TU(x) (x*1000/1024)
84 #define SN_GT(x, y) ((long) (y) - (long) (x) < 0)
85 #define SN_LT(x, y) ((long) (x) - (long) (y) < 0)
86
87 #define net_traversal_jiffies(s) \
88         msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
89 #define default_lifetime(s) \
90         MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
91 #define min_preq_int_jiff(s) \
92         (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
93 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
94 #define disc_timeout_jiff(s) \
95         msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
96
97 enum mpath_frame_type {
98         MPATH_PREQ = 0,
99         MPATH_PREP,
100         MPATH_PERR,
101         MPATH_RANN
102 };
103
104 static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
105
106 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
107                 u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target,
108                 __le32 target_sn, const u8 *da, u8 hop_count, u8 ttl,
109                 __le32 lifetime, __le32 metric, __le32 preq_id,
110                 struct ieee80211_sub_if_data *sdata)
111 {
112         struct ieee80211_local *local = sdata->local;
113         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
114         struct ieee80211_mgmt *mgmt;
115         u8 *pos;
116         int ie_len;
117
118         if (!skb)
119                 return -1;
120         skb_reserve(skb, local->hw.extra_tx_headroom);
121         /* 25 is the size of the common mgmt part (24) plus the size of the
122          * common action part (1)
123          */
124         mgmt = (struct ieee80211_mgmt *)
125                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
126         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
127         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
128                                           IEEE80211_STYPE_ACTION);
129
130         memcpy(mgmt->da, da, ETH_ALEN);
131         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
132         /* BSSID == SA */
133         memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
134         mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
135         mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
136
137         switch (action) {
138         case MPATH_PREQ:
139                 mhwmp_dbg("sending PREQ to %pM\n", target);
140                 ie_len = 37;
141                 pos = skb_put(skb, 2 + ie_len);
142                 *pos++ = WLAN_EID_PREQ;
143                 break;
144         case MPATH_PREP:
145                 mhwmp_dbg("sending PREP to %pM\n", target);
146                 ie_len = 31;
147                 pos = skb_put(skb, 2 + ie_len);
148                 *pos++ = WLAN_EID_PREP;
149                 break;
150         case MPATH_RANN:
151                 mhwmp_dbg("sending RANN from %pM\n", orig_addr);
152                 ie_len = sizeof(struct ieee80211_rann_ie);
153                 pos = skb_put(skb, 2 + ie_len);
154                 *pos++ = WLAN_EID_RANN;
155                 break;
156         default:
157                 kfree_skb(skb);
158                 return -ENOTSUPP;
159                 break;
160         }
161         *pos++ = ie_len;
162         *pos++ = flags;
163         *pos++ = hop_count;
164         *pos++ = ttl;
165         if (action == MPATH_PREQ) {
166                 memcpy(pos, &preq_id, 4);
167                 pos += 4;
168         }
169         memcpy(pos, orig_addr, ETH_ALEN);
170         pos += ETH_ALEN;
171         memcpy(pos, &orig_sn, 4);
172         pos += 4;
173         if (action != MPATH_RANN) {
174                 memcpy(pos, &lifetime, 4);
175                 pos += 4;
176         }
177         memcpy(pos, &metric, 4);
178         pos += 4;
179         if (action == MPATH_PREQ) {
180                 /* destination count */
181                 *pos++ = 1;
182                 *pos++ = target_flags;
183         }
184         if (action != MPATH_RANN) {
185                 memcpy(pos, target, ETH_ALEN);
186                 pos += ETH_ALEN;
187                 memcpy(pos, &target_sn, 4);
188         }
189
190         ieee80211_tx_skb(sdata, skb);
191         return 0;
192 }
193
194 /**
195  * mesh_send_path error - Sends a PERR mesh management frame
196  *
197  * @target: broken destination
198  * @target_sn: SN of the broken destination
199  * @target_rcode: reason code for this PERR
200  * @ra: node this frame is addressed to
201  */
202 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
203                        __le16 target_rcode, const u8 *ra,
204                        struct ieee80211_sub_if_data *sdata)
205 {
206         struct ieee80211_local *local = sdata->local;
207         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
208         struct ieee80211_mgmt *mgmt;
209         u8 *pos;
210         int ie_len;
211
212         if (!skb)
213                 return -1;
214         skb_reserve(skb, local->hw.extra_tx_headroom);
215         /* 25 is the size of the common mgmt part (24) plus the size of the
216          * common action part (1)
217          */
218         mgmt = (struct ieee80211_mgmt *)
219                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
220         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
221         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
222                                           IEEE80211_STYPE_ACTION);
223
224         memcpy(mgmt->da, ra, ETH_ALEN);
225         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
226         /* BSSID is left zeroed, wildcard value */
227         mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
228         mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
229         ie_len = 15;
230         pos = skb_put(skb, 2 + ie_len);
231         *pos++ = WLAN_EID_PERR;
232         *pos++ = ie_len;
233         /* ttl */
234         *pos++ = MESH_TTL;
235         /* number of destinations */
236         *pos++ = 1;
237         /*
238          * flags bit, bit 1 is unset if we know the sequence number and
239          * bit 2 is set if we have a reason code
240          */
241         *pos = 0;
242         if (!target_sn)
243                 *pos |= MP_F_USN;
244         if (target_rcode)
245                 *pos |= MP_F_RCODE;
246         pos++;
247         memcpy(pos, target, ETH_ALEN);
248         pos += ETH_ALEN;
249         memcpy(pos, &target_sn, 4);
250         pos += 4;
251         memcpy(pos, &target_rcode, 2);
252
253         ieee80211_tx_skb(sdata, skb);
254         return 0;
255 }
256
257 void ieee80211s_update_metric(struct ieee80211_local *local,
258                 struct sta_info *stainfo, struct sk_buff *skb)
259 {
260         struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
261         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
262         int failed;
263
264         if (!ieee80211_is_data(hdr->frame_control))
265                 return;
266
267         failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
268
269         /* moving average, scaled to 100 */
270         stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
271         if (stainfo->fail_avg > 95)
272                 mesh_plink_broken(stainfo);
273 }
274
275 static u32 airtime_link_metric_get(struct ieee80211_local *local,
276                                    struct sta_info *sta)
277 {
278         struct ieee80211_supported_band *sband;
279         /* This should be adjusted for each device */
280         int device_constant = 1 << ARITH_SHIFT;
281         int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
282         int s_unit = 1 << ARITH_SHIFT;
283         int rate, err;
284         u32 tx_time, estimated_retx;
285         u64 result;
286
287         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
288
289         if (sta->fail_avg >= 100)
290                 return MAX_METRIC;
291
292         if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
293                 return MAX_METRIC;
294
295         err = (sta->fail_avg << ARITH_SHIFT) / 100;
296
297         /* bitrate is in units of 100 Kbps, while we need rate in units of
298          * 1Mbps. This will be corrected on tx_time computation.
299          */
300         rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
301         tx_time = (device_constant + 10 * test_frame_len / rate);
302         estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
303         result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
304         return (u32)result;
305 }
306
307 /**
308  * hwmp_route_info_get - Update routing info to originator and transmitter
309  *
310  * @sdata: local mesh subif
311  * @mgmt: mesh management frame
312  * @hwmp_ie: hwmp information element (PREP or PREQ)
313  *
314  * This function updates the path routing information to the originator and the
315  * transmitter of a HWMP PREQ or PREP frame.
316  *
317  * Returns: metric to frame originator or 0 if the frame should not be further
318  * processed
319  *
320  * Notes: this function is the only place (besides user-provided info) where
321  * path routing information is updated.
322  */
323 static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
324                             struct ieee80211_mgmt *mgmt,
325                             u8 *hwmp_ie, enum mpath_frame_type action)
326 {
327         struct ieee80211_local *local = sdata->local;
328         struct mesh_path *mpath;
329         struct sta_info *sta;
330         bool fresh_info;
331         u8 *orig_addr, *ta;
332         u32 orig_sn, orig_metric;
333         unsigned long orig_lifetime, exp_time;
334         u32 last_hop_metric, new_metric;
335         bool process = true;
336
337         rcu_read_lock();
338         sta = sta_info_get(local, mgmt->sa);
339         if (!sta) {
340                 rcu_read_unlock();
341                 return 0;
342         }
343
344         last_hop_metric = airtime_link_metric_get(local, sta);
345         /* Update and check originator routing info */
346         fresh_info = true;
347
348         switch (action) {
349         case MPATH_PREQ:
350                 orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
351                 orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
352                 orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
353                 orig_metric = PREQ_IE_METRIC(hwmp_ie);
354                 break;
355         case MPATH_PREP:
356                 /* Originator here refers to the MP that was the destination in
357                  * the Path Request. The draft refers to that MP as the
358                  * destination address, even though usually it is the origin of
359                  * the PREP frame. We divert from the nomenclature in the draft
360                  * so that we can easily use a single function to gather path
361                  * information from both PREQ and PREP frames.
362                  */
363                 orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
364                 orig_sn = PREP_IE_ORIG_SN(hwmp_ie);
365                 orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
366                 orig_metric = PREP_IE_METRIC(hwmp_ie);
367                 break;
368         default:
369                 rcu_read_unlock();
370                 return 0;
371         }
372         new_metric = orig_metric + last_hop_metric;
373         if (new_metric < orig_metric)
374                 new_metric = MAX_METRIC;
375         exp_time = TU_TO_EXP_TIME(orig_lifetime);
376
377         if (memcmp(orig_addr, sdata->dev->dev_addr, ETH_ALEN) == 0) {
378                 /* This MP is the originator, we are not interested in this
379                  * frame, except for updating transmitter's path info.
380                  */
381                 process = false;
382                 fresh_info = false;
383         } else {
384                 mpath = mesh_path_lookup(orig_addr, sdata);
385                 if (mpath) {
386                         spin_lock_bh(&mpath->state_lock);
387                         if (mpath->flags & MESH_PATH_FIXED)
388                                 fresh_info = false;
389                         else if ((mpath->flags & MESH_PATH_ACTIVE) &&
390                             (mpath->flags & MESH_PATH_SN_VALID)) {
391                                 if (SN_GT(mpath->sn, orig_sn) ||
392                                     (mpath->sn == orig_sn &&
393                                      action == MPATH_PREQ &&
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->dev->dev_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.dot11MeshTTL;
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 void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
564                                     struct ieee80211_mgmt *mgmt,
565                                     u8 *prep_elem, u32 metric)
566 {
567         struct mesh_path *mpath;
568         u8 *target_addr, *orig_addr;
569         u8 ttl, hopcount, flags;
570         u8 next_hop[ETH_ALEN];
571         u32 target_sn, orig_sn, lifetime;
572
573         mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem));
574
575         /* Note that we divert from the draft nomenclature and denominate
576          * destination to what the draft refers to as origininator. So in this
577          * function destnation refers to the final destination of the PREP,
578          * which corresponds with the originator of the PREQ which this PREP
579          * replies
580          */
581         target_addr = PREP_IE_TARGET_ADDR(prep_elem);
582         if (memcmp(target_addr, sdata->dev->dev_addr, ETH_ALEN) == 0)
583                 /* destination, no forwarding required */
584                 return;
585
586         ttl = PREP_IE_TTL(prep_elem);
587         if (ttl <= 1) {
588                 sdata->u.mesh.mshstats.dropped_frames_ttl++;
589                 return;
590         }
591
592         rcu_read_lock();
593         mpath = mesh_path_lookup(target_addr, sdata);
594         if (mpath)
595                 spin_lock_bh(&mpath->state_lock);
596         else
597                 goto fail;
598         if (!(mpath->flags & MESH_PATH_ACTIVE)) {
599                 spin_unlock_bh(&mpath->state_lock);
600                 goto fail;
601         }
602         memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN);
603         spin_unlock_bh(&mpath->state_lock);
604         --ttl;
605         flags = PREP_IE_FLAGS(prep_elem);
606         lifetime = PREP_IE_LIFETIME(prep_elem);
607         hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
608         orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
609         target_sn = PREP_IE_TARGET_SN(prep_elem);
610         orig_sn = PREP_IE_ORIG_SN(prep_elem);
611
612         mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
613                 cpu_to_le32(orig_sn), 0, target_addr,
614                 cpu_to_le32(target_sn), mpath->next_hop->sta.addr, hopcount,
615                 ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
616                 0, sdata);
617         rcu_read_unlock();
618
619         sdata->u.mesh.mshstats.fwded_unicast++;
620         sdata->u.mesh.mshstats.fwded_frames++;
621         return;
622
623 fail:
624         rcu_read_unlock();
625         sdata->u.mesh.mshstats.dropped_frames_no_route++;
626         return;
627 }
628
629 static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
630                              struct ieee80211_mgmt *mgmt, u8 *perr_elem)
631 {
632         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
633         struct mesh_path *mpath;
634         u8 ttl;
635         u8 *ta, *target_addr;
636         u8 target_flags;
637         u32 target_sn;
638         u16 target_rcode;
639
640         ta = mgmt->sa;
641         ttl = PERR_IE_TTL(perr_elem);
642         if (ttl <= 1) {
643                 ifmsh->mshstats.dropped_frames_ttl++;
644                 return;
645         }
646         ttl--;
647         target_flags = PERR_IE_TARGET_FLAGS(perr_elem);
648         target_addr = PERR_IE_TARGET_ADDR(perr_elem);
649         target_sn = PERR_IE_TARGET_SN(perr_elem);
650         target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
651
652         rcu_read_lock();
653         mpath = mesh_path_lookup(target_addr, sdata);
654         if (mpath) {
655                 spin_lock_bh(&mpath->state_lock);
656                 if (mpath->flags & MESH_PATH_ACTIVE &&
657                     memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 &&
658                     (!(mpath->flags & MESH_PATH_SN_VALID) ||
659                     SN_GT(target_sn, mpath->sn))) {
660                         mpath->flags &= ~MESH_PATH_ACTIVE;
661                         mpath->sn = target_sn;
662                         spin_unlock_bh(&mpath->state_lock);
663                         mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
664                                            cpu_to_le16(target_rcode),
665                                            broadcast_addr, sdata);
666                 } else
667                         spin_unlock_bh(&mpath->state_lock);
668         }
669         rcu_read_unlock();
670 }
671
672 static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
673                                 struct ieee80211_mgmt *mgmt,
674                                 struct ieee80211_rann_ie *rann)
675 {
676         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
677         struct mesh_path *mpath;
678         u8 *ta;
679         u8 ttl, flags, hopcount;
680         u8 *orig_addr;
681         u32 orig_sn, metric;
682
683         ta = mgmt->sa;
684         ttl = rann->rann_ttl;
685         if (ttl <= 1) {
686                 ifmsh->mshstats.dropped_frames_ttl++;
687                 return;
688         }
689         ttl--;
690         flags = rann->rann_flags;
691         orig_addr = rann->rann_addr;
692         orig_sn = rann->rann_seq;
693         hopcount = rann->rann_hopcount;
694         hopcount++;
695         metric = rann->rann_metric;
696         mhwmp_dbg("received RANN from %pM\n", orig_addr);
697
698         rcu_read_lock();
699         mpath = mesh_path_lookup(orig_addr, sdata);
700         if (!mpath) {
701                 mesh_path_add(orig_addr, sdata);
702                 mpath = mesh_path_lookup(orig_addr, sdata);
703                 if (!mpath) {
704                         rcu_read_unlock();
705                         sdata->u.mesh.mshstats.dropped_frames_no_route++;
706                         return;
707                 }
708                 mesh_queue_preq(mpath,
709                                 PREQ_Q_F_START | PREQ_Q_F_REFRESH);
710         }
711         if (mpath->sn < orig_sn) {
712                 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
713                                        cpu_to_le32(orig_sn),
714                                        0, NULL, 0, broadcast_addr,
715                                        hopcount, ttl, 0,
716                                        cpu_to_le32(metric + mpath->metric),
717                                        0, sdata);
718                 mpath->sn = orig_sn;
719         }
720         rcu_read_unlock();
721 }
722
723
724 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
725                             struct ieee80211_mgmt *mgmt,
726                             size_t len)
727 {
728         struct ieee802_11_elems elems;
729         size_t baselen;
730         u32 last_hop_metric;
731
732         /* need action_code */
733         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
734                 return;
735
736         baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
737         ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
738                         len - baselen, &elems);
739
740         if (elems.preq) {
741                 if (elems.preq_len != 37)
742                         /* Right now we support just 1 destination and no AE */
743                         return;
744                 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
745                                                       MPATH_PREQ);
746                 if (last_hop_metric)
747                         hwmp_preq_frame_process(sdata, mgmt, elems.preq,
748                                                 last_hop_metric);
749         }
750         if (elems.prep) {
751                 if (elems.prep_len != 31)
752                         /* Right now we support no AE */
753                         return;
754                 last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
755                                                       MPATH_PREP);
756                 if (last_hop_metric)
757                         hwmp_prep_frame_process(sdata, mgmt, elems.prep,
758                                                 last_hop_metric);
759         }
760         if (elems.perr) {
761                 if (elems.perr_len != 15)
762                         /* Right now we support only one destination per PERR */
763                         return;
764                 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
765         }
766         if (elems.rann)
767                 hwmp_rann_frame_process(sdata, mgmt, elems.rann);
768 }
769
770 /**
771  * mesh_queue_preq - queue a PREQ to a given destination
772  *
773  * @mpath: mesh path to discover
774  * @flags: special attributes of the PREQ to be sent
775  *
776  * Locking: the function must be called from within a rcu read lock block.
777  *
778  */
779 static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
780 {
781         struct ieee80211_sub_if_data *sdata = mpath->sdata;
782         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
783         struct mesh_preq_queue *preq_node;
784
785         preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
786         if (!preq_node) {
787                 mhwmp_dbg("could not allocate PREQ node\n");
788                 return;
789         }
790
791         spin_lock(&ifmsh->mesh_preq_queue_lock);
792         if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
793                 spin_unlock(&ifmsh->mesh_preq_queue_lock);
794                 kfree(preq_node);
795                 if (printk_ratelimit())
796                         mhwmp_dbg("PREQ node queue full\n");
797                 return;
798         }
799
800         memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
801         preq_node->flags = flags;
802
803         list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
804         ++ifmsh->preq_queue_len;
805         spin_unlock(&ifmsh->mesh_preq_queue_lock);
806
807         if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
808                 ieee80211_queue_work(&sdata->local->hw, &ifmsh->work);
809
810         else if (time_before(jiffies, ifmsh->last_preq)) {
811                 /* avoid long wait if did not send preqs for a long time
812                  * and jiffies wrapped around
813                  */
814                 ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
815                 ieee80211_queue_work(&sdata->local->hw, &ifmsh->work);
816         } else
817                 mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
818                                                 min_preq_int_jiff(sdata));
819 }
820
821 /**
822  * mesh_path_start_discovery - launch a path discovery from the PREQ queue
823  *
824  * @sdata: local mesh subif
825  */
826 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
827 {
828         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
829         struct mesh_preq_queue *preq_node;
830         struct mesh_path *mpath;
831         u8 ttl, target_flags;
832         u32 lifetime;
833
834         spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
835         if (!ifmsh->preq_queue_len ||
836                 time_before(jiffies, ifmsh->last_preq +
837                                 min_preq_int_jiff(sdata))) {
838                 spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
839                 return;
840         }
841
842         preq_node = list_first_entry(&ifmsh->preq_queue.list,
843                         struct mesh_preq_queue, list);
844         list_del(&preq_node->list);
845         --ifmsh->preq_queue_len;
846         spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
847
848         rcu_read_lock();
849         mpath = mesh_path_lookup(preq_node->dst, sdata);
850         if (!mpath)
851                 goto enddiscovery;
852
853         spin_lock_bh(&mpath->state_lock);
854         if (preq_node->flags & PREQ_Q_F_START) {
855                 if (mpath->flags & MESH_PATH_RESOLVING) {
856                         spin_unlock_bh(&mpath->state_lock);
857                         goto enddiscovery;
858                 } else {
859                         mpath->flags &= ~MESH_PATH_RESOLVED;
860                         mpath->flags |= MESH_PATH_RESOLVING;
861                         mpath->discovery_retries = 0;
862                         mpath->discovery_timeout = disc_timeout_jiff(sdata);
863                 }
864         } else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
865                         mpath->flags & MESH_PATH_RESOLVED) {
866                 mpath->flags &= ~MESH_PATH_RESOLVING;
867                 spin_unlock_bh(&mpath->state_lock);
868                 goto enddiscovery;
869         }
870
871         ifmsh->last_preq = jiffies;
872
873         if (time_after(jiffies, ifmsh->last_sn_update +
874                                 net_traversal_jiffies(sdata)) ||
875             time_before(jiffies, ifmsh->last_sn_update)) {
876                 ++ifmsh->sn;
877                 sdata->u.mesh.last_sn_update = jiffies;
878         }
879         lifetime = default_lifetime(sdata);
880         ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
881         if (ttl == 0) {
882                 sdata->u.mesh.mshstats.dropped_frames_ttl++;
883                 spin_unlock_bh(&mpath->state_lock);
884                 goto enddiscovery;
885         }
886
887         if (preq_node->flags & PREQ_Q_F_REFRESH)
888                 target_flags = MP_F_DO;
889         else
890                 target_flags = MP_F_RF;
891
892         spin_unlock_bh(&mpath->state_lock);
893         mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->dev->dev_addr,
894                         cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
895                         cpu_to_le32(mpath->sn), broadcast_addr, 0,
896                         ttl, cpu_to_le32(lifetime), 0,
897                         cpu_to_le32(ifmsh->preq_id++), sdata);
898         mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
899
900 enddiscovery:
901         rcu_read_unlock();
902         kfree(preq_node);
903 }
904
905 /**
906  * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
907  *
908  * @skb: 802.11 frame to be sent
909  * @sdata: network subif the frame will be sent through
910  *
911  * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
912  * found, the function will start a path discovery and queue the frame so it is
913  * sent when the path is resolved. This means the caller must not free the skb
914  * in this case.
915  */
916 int mesh_nexthop_lookup(struct sk_buff *skb,
917                         struct ieee80211_sub_if_data *sdata)
918 {
919         struct sk_buff *skb_to_free = NULL;
920         struct mesh_path *mpath;
921         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
922         u8 *target_addr = hdr->addr3;
923         int err = 0;
924
925         rcu_read_lock();
926         mpath = mesh_path_lookup(target_addr, sdata);
927
928         if (!mpath) {
929                 mesh_path_add(target_addr, sdata);
930                 mpath = mesh_path_lookup(target_addr, sdata);
931                 if (!mpath) {
932                         sdata->u.mesh.mshstats.dropped_frames_no_route++;
933                         err = -ENOSPC;
934                         goto endlookup;
935                 }
936         }
937
938         if (mpath->flags & MESH_PATH_ACTIVE) {
939                 if (time_after(jiffies,
940                                mpath->exp_time +
941                                msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
942                     !memcmp(sdata->dev->dev_addr, hdr->addr4, ETH_ALEN) &&
943                     !(mpath->flags & MESH_PATH_RESOLVING) &&
944                     !(mpath->flags & MESH_PATH_FIXED)) {
945                         mesh_queue_preq(mpath,
946                                         PREQ_Q_F_START | PREQ_Q_F_REFRESH);
947                 }
948                 memcpy(hdr->addr1, mpath->next_hop->sta.addr, ETH_ALEN);
949         } else {
950                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
951                 if (!(mpath->flags & MESH_PATH_RESOLVING)) {
952                         /* Start discovery only if it is not running yet */
953                         mesh_queue_preq(mpath, PREQ_Q_F_START);
954                 }
955
956                 if (skb_queue_len(&mpath->frame_queue) >=
957                                 MESH_FRAME_QUEUE_LEN)
958                         skb_to_free = skb_dequeue(&mpath->frame_queue);
959
960                 info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
961                 skb_queue_tail(&mpath->frame_queue, skb);
962                 if (skb_to_free)
963                         mesh_path_discard_frame(skb_to_free, sdata);
964                 err = -ENOENT;
965         }
966
967 endlookup:
968         rcu_read_unlock();
969         return err;
970 }
971
972 void mesh_path_timer(unsigned long data)
973 {
974         struct ieee80211_sub_if_data *sdata;
975         struct mesh_path *mpath;
976
977         rcu_read_lock();
978         mpath = (struct mesh_path *) data;
979         mpath = rcu_dereference(mpath);
980         if (!mpath)
981                 goto endmpathtimer;
982         sdata = mpath->sdata;
983
984         if (sdata->local->quiescing) {
985                 rcu_read_unlock();
986                 return;
987         }
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 endmpathtimer:
1005         rcu_read_unlock();
1006 }
1007
1008 void
1009 mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
1010 {
1011         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
1012
1013         mesh_path_sel_frame_tx(MPATH_RANN, 0, sdata->dev->dev_addr,
1014                                cpu_to_le32(++ifmsh->sn),
1015                                0, NULL, 0, broadcast_addr,
1016                                0, MESH_TTL, 0, 0, 0, sdata);
1017 }