~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/mac80211/mesh_pathtbl.c

Version: ~ [ linux-5.13-rc1 ] ~ [ linux-5.12.2 ] ~ [ linux-5.11.19 ] ~ [ linux-5.10.35 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.117 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.190 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.232 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.268 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.268 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/etherdevice.h>
 11 #include <linux/list.h>
 12 #include <linux/random.h>
 13 #include <linux/slab.h>
 14 #include <linux/spinlock.h>
 15 #include <linux/string.h>
 16 #include <net/mac80211.h>
 17 #include "wme.h"
 18 #include "ieee80211_i.h"
 19 #include "mesh.h"
 20 
 21 static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
 22 
 23 static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
 24 {
 25         /* Use last four bytes of hw addr as hash index */
 26         return jhash_1word(*(u32 *)(addr+2), seed);
 27 }
 28 
 29 static const struct rhashtable_params mesh_rht_params = {
 30         .nelem_hint = 2,
 31         .automatic_shrinking = true,
 32         .key_len = ETH_ALEN,
 33         .key_offset = offsetof(struct mesh_path, dst),
 34         .head_offset = offsetof(struct mesh_path, rhash),
 35         .hashfn = mesh_table_hash,
 36 };
 37 
 38 static inline bool mpath_expired(struct mesh_path *mpath)
 39 {
 40         return (mpath->flags & MESH_PATH_ACTIVE) &&
 41                time_after(jiffies, mpath->exp_time) &&
 42                !(mpath->flags & MESH_PATH_FIXED);
 43 }
 44 
 45 static void mesh_path_rht_free(void *ptr, void *tblptr)
 46 {
 47         struct mesh_path *mpath = ptr;
 48         struct mesh_table *tbl = tblptr;
 49 
 50         mesh_path_free_rcu(tbl, mpath);
 51 }
 52 
 53 static struct mesh_table *mesh_table_alloc(void)
 54 {
 55         struct mesh_table *newtbl;
 56 
 57         newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
 58         if (!newtbl)
 59                 return NULL;
 60 
 61         INIT_HLIST_HEAD(&newtbl->known_gates);
 62         atomic_set(&newtbl->entries,  0);
 63         spin_lock_init(&newtbl->gates_lock);
 64 
 65         return newtbl;
 66 }
 67 
 68 static void mesh_table_free(struct mesh_table *tbl)
 69 {
 70         rhashtable_free_and_destroy(&tbl->rhead,
 71                                     mesh_path_rht_free, tbl);
 72         kfree(tbl);
 73 }
 74 
 75 /**
 76  *
 77  * mesh_path_assign_nexthop - update mesh path next hop
 78  *
 79  * @mpath: mesh path to update
 80  * @sta: next hop to assign
 81  *
 82  * Locking: mpath->state_lock must be held when calling this function
 83  */
 84 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
 85 {
 86         struct sk_buff *skb;
 87         struct ieee80211_hdr *hdr;
 88         unsigned long flags;
 89 
 90         rcu_assign_pointer(mpath->next_hop, sta);
 91 
 92         spin_lock_irqsave(&mpath->frame_queue.lock, flags);
 93         skb_queue_walk(&mpath->frame_queue, skb) {
 94                 hdr = (struct ieee80211_hdr *) skb->data;
 95                 memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
 96                 memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
 97                 ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr);
 98         }
 99 
100         spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
101 }
102 
103 static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
104                              struct mesh_path *gate_mpath)
105 {
106         struct ieee80211_hdr *hdr;
107         struct ieee80211s_hdr *mshdr;
108         int mesh_hdrlen, hdrlen;
109         char *next_hop;
110 
111         hdr = (struct ieee80211_hdr *) skb->data;
112         hdrlen = ieee80211_hdrlen(hdr->frame_control);
113         mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
114 
115         if (!(mshdr->flags & MESH_FLAGS_AE)) {
116                 /* size of the fixed part of the mesh header */
117                 mesh_hdrlen = 6;
118 
119                 /* make room for the two extended addresses */
120                 skb_push(skb, 2 * ETH_ALEN);
121                 memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
122 
123                 hdr = (struct ieee80211_hdr *) skb->data;
124 
125                 /* we preserve the previous mesh header and only add
126                  * the new addreses */
127                 mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
128                 mshdr->flags = MESH_FLAGS_AE_A5_A6;
129                 memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
130                 memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
131         }
132 
133         /* update next hop */
134         hdr = (struct ieee80211_hdr *) skb->data;
135         rcu_read_lock();
136         next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
137         memcpy(hdr->addr1, next_hop, ETH_ALEN);
138         rcu_read_unlock();
139         memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
140         memcpy(hdr->addr3, dst_addr, ETH_ALEN);
141 }
142 
143 /**
144  *
145  * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
146  *
147  * This function is used to transfer or copy frames from an unresolved mpath to
148  * a gate mpath.  The function also adds the Address Extension field and
149  * updates the next hop.
150  *
151  * If a frame already has an Address Extension field, only the next hop and
152  * destination addresses are updated.
153  *
154  * The gate mpath must be an active mpath with a valid mpath->next_hop.
155  *
156  * @mpath: An active mpath the frames will be sent to (i.e. the gate)
157  * @from_mpath: The failed mpath
158  * @copy: When true, copy all the frames to the new mpath queue.  When false,
159  * move them.
160  */
161 static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
162                                     struct mesh_path *from_mpath,
163                                     bool copy)
164 {
165         struct sk_buff *skb, *fskb, *tmp;
166         struct sk_buff_head failq;
167         unsigned long flags;
168 
169         if (WARN_ON(gate_mpath == from_mpath))
170                 return;
171         if (WARN_ON(!gate_mpath->next_hop))
172                 return;
173 
174         __skb_queue_head_init(&failq);
175 
176         spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
177         skb_queue_splice_init(&from_mpath->frame_queue, &failq);
178         spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
179 
180         skb_queue_walk_safe(&failq, fskb, tmp) {
181                 if (skb_queue_len(&gate_mpath->frame_queue) >=
182                                   MESH_FRAME_QUEUE_LEN) {
183                         mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
184                         break;
185                 }
186 
187                 skb = skb_copy(fskb, GFP_ATOMIC);
188                 if (WARN_ON(!skb))
189                         break;
190 
191                 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
192                 skb_queue_tail(&gate_mpath->frame_queue, skb);
193 
194                 if (copy)
195                         continue;
196 
197                 __skb_unlink(fskb, &failq);
198                 kfree_skb(fskb);
199         }
200 
201         mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
202                   gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
203 
204         if (!copy)
205                 return;
206 
207         spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
208         skb_queue_splice(&failq, &from_mpath->frame_queue);
209         spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
210 }
211 
212 
213 static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst,
214                                       struct ieee80211_sub_if_data *sdata)
215 {
216         struct mesh_path *mpath;
217 
218         mpath = rhashtable_lookup_fast(&tbl->rhead, dst, mesh_rht_params);
219 
220         if (mpath && mpath_expired(mpath)) {
221                 spin_lock_bh(&mpath->state_lock);
222                 mpath->flags &= ~MESH_PATH_ACTIVE;
223                 spin_unlock_bh(&mpath->state_lock);
224         }
225         return mpath;
226 }
227 
228 /**
229  * mesh_path_lookup - look up a path in the mesh path table
230  * @sdata: local subif
231  * @dst: hardware address (ETH_ALEN length) of destination
232  *
233  * Returns: pointer to the mesh path structure, or NULL if not found
234  *
235  * Locking: must be called within a read rcu section.
236  */
237 struct mesh_path *
238 mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
239 {
240         return mpath_lookup(sdata->u.mesh.mesh_paths, dst, sdata);
241 }
242 
243 struct mesh_path *
244 mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
245 {
246         return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata);
247 }
248 
249 static struct mesh_path *
250 __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
251 {
252         int i = 0, ret;
253         struct mesh_path *mpath = NULL;
254         struct rhashtable_iter iter;
255 
256         ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
257         if (ret)
258                 return NULL;
259 
260         ret = rhashtable_walk_start(&iter);
261         if (ret && ret != -EAGAIN)
262                 goto err;
263 
264         while ((mpath = rhashtable_walk_next(&iter))) {
265                 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
266                         continue;
267                 if (IS_ERR(mpath))
268                         break;
269                 if (i++ == idx)
270                         break;
271         }
272 err:
273         rhashtable_walk_stop(&iter);
274         rhashtable_walk_exit(&iter);
275 
276         if (IS_ERR(mpath) || !mpath)
277                 return NULL;
278 
279         if (mpath_expired(mpath)) {
280                 spin_lock_bh(&mpath->state_lock);
281                 mpath->flags &= ~MESH_PATH_ACTIVE;
282                 spin_unlock_bh(&mpath->state_lock);
283         }
284         return mpath;
285 }
286 
287 /**
288  * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
289  * @idx: index
290  * @sdata: local subif, or NULL for all entries
291  *
292  * Returns: pointer to the mesh path structure, or NULL if not found.
293  *
294  * Locking: must be called within a read rcu section.
295  */
296 struct mesh_path *
297 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
298 {
299         return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx);
300 }
301 
302 /**
303  * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
304  * @idx: index
305  * @sdata: local subif, or NULL for all entries
306  *
307  * Returns: pointer to the proxy path structure, or NULL if not found.
308  *
309  * Locking: must be called within a read rcu section.
310  */
311 struct mesh_path *
312 mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
313 {
314         return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx);
315 }
316 
317 /**
318  * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
319  * @mpath: gate path to add to table
320  */
321 int mesh_path_add_gate(struct mesh_path *mpath)
322 {
323         struct mesh_table *tbl;
324         int err;
325 
326         rcu_read_lock();
327         tbl = mpath->sdata->u.mesh.mesh_paths;
328 
329         spin_lock_bh(&mpath->state_lock);
330         if (mpath->is_gate) {
331                 err = -EEXIST;
332                 spin_unlock_bh(&mpath->state_lock);
333                 goto err_rcu;
334         }
335         mpath->is_gate = true;
336         mpath->sdata->u.mesh.num_gates++;
337 
338         spin_lock(&tbl->gates_lock);
339         hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
340         spin_unlock(&tbl->gates_lock);
341 
342         spin_unlock_bh(&mpath->state_lock);
343 
344         mpath_dbg(mpath->sdata,
345                   "Mesh path: Recorded new gate: %pM. %d known gates\n",
346                   mpath->dst, mpath->sdata->u.mesh.num_gates);
347         err = 0;
348 err_rcu:
349         rcu_read_unlock();
350         return err;
351 }
352 
353 /**
354  * mesh_gate_del - remove a mesh gate from the list of known gates
355  * @tbl: table which holds our list of known gates
356  * @mpath: gate mpath
357  */
358 static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
359 {
360         lockdep_assert_held(&mpath->state_lock);
361         if (!mpath->is_gate)
362                 return;
363 
364         mpath->is_gate = false;
365         spin_lock_bh(&tbl->gates_lock);
366         hlist_del_rcu(&mpath->gate_list);
367         mpath->sdata->u.mesh.num_gates--;
368         spin_unlock_bh(&tbl->gates_lock);
369 
370         mpath_dbg(mpath->sdata,
371                   "Mesh path: Deleted gate: %pM. %d known gates\n",
372                   mpath->dst, mpath->sdata->u.mesh.num_gates);
373 }
374 
375 /**
376  * mesh_gate_num - number of gates known to this interface
377  * @sdata: subif data
378  */
379 int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
380 {
381         return sdata->u.mesh.num_gates;
382 }
383 
384 static
385 struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
386                                 const u8 *dst, gfp_t gfp_flags)
387 {
388         struct mesh_path *new_mpath;
389 
390         new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
391         if (!new_mpath)
392                 return NULL;
393 
394         memcpy(new_mpath->dst, dst, ETH_ALEN);
395         eth_broadcast_addr(new_mpath->rann_snd_addr);
396         new_mpath->is_root = false;
397         new_mpath->sdata = sdata;
398         new_mpath->flags = 0;
399         skb_queue_head_init(&new_mpath->frame_queue);
400         new_mpath->exp_time = jiffies;
401         spin_lock_init(&new_mpath->state_lock);
402         timer_setup(&new_mpath->timer, mesh_path_timer, 0);
403 
404         return new_mpath;
405 }
406 
407 /**
408  * mesh_path_add - allocate and add a new path to the mesh path table
409  * @dst: destination address of the path (ETH_ALEN length)
410  * @sdata: local subif
411  *
412  * Returns: 0 on success
413  *
414  * State: the initial state of the new path is set to 0
415  */
416 struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
417                                 const u8 *dst)
418 {
419         struct mesh_table *tbl;
420         struct mesh_path *mpath, *new_mpath;
421         int ret;
422 
423         if (ether_addr_equal(dst, sdata->vif.addr))
424                 /* never add ourselves as neighbours */
425                 return ERR_PTR(-ENOTSUPP);
426 
427         if (is_multicast_ether_addr(dst))
428                 return ERR_PTR(-ENOTSUPP);
429 
430         if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
431                 return ERR_PTR(-ENOSPC);
432 
433         new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
434         if (!new_mpath)
435                 return ERR_PTR(-ENOMEM);
436 
437         tbl = sdata->u.mesh.mesh_paths;
438         do {
439                 ret = rhashtable_lookup_insert_fast(&tbl->rhead,
440                                                     &new_mpath->rhash,
441                                                     mesh_rht_params);
442 
443                 if (ret == -EEXIST)
444                         mpath = rhashtable_lookup_fast(&tbl->rhead,
445                                                        dst,
446                                                        mesh_rht_params);
447 
448         } while (unlikely(ret == -EEXIST && !mpath));
449 
450         if (ret && ret != -EEXIST)
451                 return ERR_PTR(ret);
452 
453         /* At this point either new_mpath was added, or we found a
454          * matching entry already in the table; in the latter case
455          * free the unnecessary new entry.
456          */
457         if (ret == -EEXIST) {
458                 kfree(new_mpath);
459                 new_mpath = mpath;
460         }
461         sdata->u.mesh.mesh_paths_generation++;
462         return new_mpath;
463 }
464 
465 int mpp_path_add(struct ieee80211_sub_if_data *sdata,
466                  const u8 *dst, const u8 *mpp)
467 {
468         struct mesh_table *tbl;
469         struct mesh_path *new_mpath;
470         int ret;
471 
472         if (ether_addr_equal(dst, sdata->vif.addr))
473                 /* never add ourselves as neighbours */
474                 return -ENOTSUPP;
475 
476         if (is_multicast_ether_addr(dst))
477                 return -ENOTSUPP;
478 
479         new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
480 
481         if (!new_mpath)
482                 return -ENOMEM;
483 
484         memcpy(new_mpath->mpp, mpp, ETH_ALEN);
485         tbl = sdata->u.mesh.mpp_paths;
486         ret = rhashtable_lookup_insert_fast(&tbl->rhead,
487                                             &new_mpath->rhash,
488                                             mesh_rht_params);
489 
490         sdata->u.mesh.mpp_paths_generation++;
491         return ret;
492 }
493 
494 
495 /**
496  * mesh_plink_broken - deactivates paths and sends perr when a link breaks
497  *
498  * @sta: broken peer link
499  *
500  * This function must be called from the rate control algorithm if enough
501  * delivery errors suggest that a peer link is no longer usable.
502  */
503 void mesh_plink_broken(struct sta_info *sta)
504 {
505         struct ieee80211_sub_if_data *sdata = sta->sdata;
506         struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
507         static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
508         struct mesh_path *mpath;
509         struct rhashtable_iter iter;
510         int ret;
511 
512         ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
513         if (ret)
514                 return;
515 
516         ret = rhashtable_walk_start(&iter);
517         if (ret && ret != -EAGAIN)
518                 goto out;
519 
520         while ((mpath = rhashtable_walk_next(&iter))) {
521                 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
522                         continue;
523                 if (IS_ERR(mpath))
524                         break;
525                 if (rcu_access_pointer(mpath->next_hop) == sta &&
526                     mpath->flags & MESH_PATH_ACTIVE &&
527                     !(mpath->flags & MESH_PATH_FIXED)) {
528                         spin_lock_bh(&mpath->state_lock);
529                         mpath->flags &= ~MESH_PATH_ACTIVE;
530                         ++mpath->sn;
531                         spin_unlock_bh(&mpath->state_lock);
532                         mesh_path_error_tx(sdata,
533                                 sdata->u.mesh.mshcfg.element_ttl,
534                                 mpath->dst, mpath->sn,
535                                 WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
536                 }
537         }
538 out:
539         rhashtable_walk_stop(&iter);
540         rhashtable_walk_exit(&iter);
541 }
542 
543 static void mesh_path_free_rcu(struct mesh_table *tbl,
544                                struct mesh_path *mpath)
545 {
546         struct ieee80211_sub_if_data *sdata = mpath->sdata;
547 
548         spin_lock_bh(&mpath->state_lock);
549         mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
550         mesh_gate_del(tbl, mpath);
551         spin_unlock_bh(&mpath->state_lock);
552         del_timer_sync(&mpath->timer);
553         atomic_dec(&sdata->u.mesh.mpaths);
554         atomic_dec(&tbl->entries);
555         kfree_rcu(mpath, rcu);
556 }
557 
558 static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
559 {
560         rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
561         mesh_path_free_rcu(tbl, mpath);
562 }
563 
564 /**
565  * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
566  *
567  * @sta: mesh peer to match
568  *
569  * RCU notes: this function is called when a mesh plink transitions from
570  * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
571  * allows path creation. This will happen before the sta can be freed (because
572  * sta_info_destroy() calls this) so any reader in a rcu read block will be
573  * protected against the plink disappearing.
574  */
575 void mesh_path_flush_by_nexthop(struct sta_info *sta)
576 {
577         struct ieee80211_sub_if_data *sdata = sta->sdata;
578         struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
579         struct mesh_path *mpath;
580         struct rhashtable_iter iter;
581         int ret;
582 
583         ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
584         if (ret)
585                 return;
586 
587         ret = rhashtable_walk_start(&iter);
588         if (ret && ret != -EAGAIN)
589                 goto out;
590 
591         while ((mpath = rhashtable_walk_next(&iter))) {
592                 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
593                         continue;
594                 if (IS_ERR(mpath))
595                         break;
596 
597                 if (rcu_access_pointer(mpath->next_hop) == sta)
598                         __mesh_path_del(tbl, mpath);
599         }
600 out:
601         rhashtable_walk_stop(&iter);
602         rhashtable_walk_exit(&iter);
603 }
604 
605 static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
606                                const u8 *proxy)
607 {
608         struct mesh_table *tbl = sdata->u.mesh.mpp_paths;
609         struct mesh_path *mpath;
610         struct rhashtable_iter iter;
611         int ret;
612 
613         ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
614         if (ret)
615                 return;
616 
617         ret = rhashtable_walk_start(&iter);
618         if (ret && ret != -EAGAIN)
619                 goto out;
620 
621         while ((mpath = rhashtable_walk_next(&iter))) {
622                 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
623                         continue;
624                 if (IS_ERR(mpath))
625                         break;
626 
627                 if (ether_addr_equal(mpath->mpp, proxy))
628                         __mesh_path_del(tbl, mpath);
629         }
630 out:
631         rhashtable_walk_stop(&iter);
632         rhashtable_walk_exit(&iter);
633 }
634 
635 static void table_flush_by_iface(struct mesh_table *tbl)
636 {
637         struct mesh_path *mpath;
638         struct rhashtable_iter iter;
639         int ret;
640 
641         ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
642         if (ret)
643                 return;
644 
645         ret = rhashtable_walk_start(&iter);
646         if (ret && ret != -EAGAIN)
647                 goto out;
648 
649         while ((mpath = rhashtable_walk_next(&iter))) {
650                 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
651                         continue;
652                 if (IS_ERR(mpath))
653                         break;
654                 __mesh_path_del(tbl, mpath);
655         }
656 out:
657         rhashtable_walk_stop(&iter);
658         rhashtable_walk_exit(&iter);
659 }
660 
661 /**
662  * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
663  *
664  * This function deletes both mesh paths as well as mesh portal paths.
665  *
666  * @sdata: interface data to match
667  *
668  */
669 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
670 {
671         table_flush_by_iface(sdata->u.mesh.mesh_paths);
672         table_flush_by_iface(sdata->u.mesh.mpp_paths);
673 }
674 
675 /**
676  * table_path_del - delete a path from the mesh or mpp table
677  *
678  * @tbl: mesh or mpp path table
679  * @sdata: local subif
680  * @addr: dst address (ETH_ALEN length)
681  *
682  * Returns: 0 if successful
683  */
684 static int table_path_del(struct mesh_table *tbl,
685                           struct ieee80211_sub_if_data *sdata,
686                           const u8 *addr)
687 {
688         struct mesh_path *mpath;
689 
690         rcu_read_lock();
691         mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
692         if (!mpath) {
693                 rcu_read_unlock();
694                 return -ENXIO;
695         }
696 
697         __mesh_path_del(tbl, mpath);
698         rcu_read_unlock();
699         return 0;
700 }
701 
702 
703 /**
704  * mesh_path_del - delete a mesh path from the table
705  *
706  * @addr: dst address (ETH_ALEN length)
707  * @sdata: local subif
708  *
709  * Returns: 0 if successful
710  */
711 int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
712 {
713         int err;
714 
715         /* flush relevant mpp entries first */
716         mpp_flush_by_proxy(sdata, addr);
717 
718         err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr);
719         sdata->u.mesh.mesh_paths_generation++;
720         return err;
721 }
722 
723 /**
724  * mesh_path_tx_pending - sends pending frames in a mesh path queue
725  *
726  * @mpath: mesh path to activate
727  *
728  * Locking: the state_lock of the mpath structure must NOT be held when calling
729  * this function.
730  */
731 void mesh_path_tx_pending(struct mesh_path *mpath)
732 {
733         if (mpath->flags & MESH_PATH_ACTIVE)
734                 ieee80211_add_pending_skbs(mpath->sdata->local,
735                                 &mpath->frame_queue);
736 }
737 
738 /**
739  * mesh_path_send_to_gates - sends pending frames to all known mesh gates
740  *
741  * @mpath: mesh path whose queue will be emptied
742  *
743  * If there is only one gate, the frames are transferred from the failed mpath
744  * queue to that gate's queue.  If there are more than one gates, the frames
745  * are copied from each gate to the next.  After frames are copied, the
746  * mpath queues are emptied onto the transmission queue.
747  */
748 int mesh_path_send_to_gates(struct mesh_path *mpath)
749 {
750         struct ieee80211_sub_if_data *sdata = mpath->sdata;
751         struct mesh_table *tbl;
752         struct mesh_path *from_mpath = mpath;
753         struct mesh_path *gate;
754         bool copy = false;
755 
756         tbl = sdata->u.mesh.mesh_paths;
757 
758         rcu_read_lock();
759         hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
760                 if (gate->flags & MESH_PATH_ACTIVE) {
761                         mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
762                         mesh_path_move_to_queue(gate, from_mpath, copy);
763                         from_mpath = gate;
764                         copy = true;
765                 } else {
766                         mpath_dbg(sdata,
767                                   "Not forwarding to %pM (flags %#x)\n",
768                                   gate->dst, gate->flags);
769                 }
770         }
771 
772         hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
773                 mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
774                 mesh_path_tx_pending(gate);
775         }
776         rcu_read_unlock();
777 
778         return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
779 }
780 
781 /**
782  * mesh_path_discard_frame - discard a frame whose path could not be resolved
783  *
784  * @skb: frame to discard
785  * @sdata: network subif the frame was to be sent through
786  *
787  * Locking: the function must me called within a rcu_read_lock region
788  */
789 void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
790                              struct sk_buff *skb)
791 {
792         kfree_skb(skb);
793         sdata->u.mesh.mshstats.dropped_frames_no_route++;
794 }
795 
796 /**
797  * mesh_path_flush_pending - free the pending queue of a mesh path
798  *
799  * @mpath: mesh path whose queue has to be freed
800  *
801  * Locking: the function must me called within a rcu_read_lock region
802  */
803 void mesh_path_flush_pending(struct mesh_path *mpath)
804 {
805         struct sk_buff *skb;
806 
807         while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
808                 mesh_path_discard_frame(mpath->sdata, skb);
809 }
810 
811 /**
812  * mesh_path_fix_nexthop - force a specific next hop for a mesh path
813  *
814  * @mpath: the mesh path to modify
815  * @next_hop: the next hop to force
816  *
817  * Locking: this function must be called holding mpath->state_lock
818  */
819 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
820 {
821         spin_lock_bh(&mpath->state_lock);
822         mesh_path_assign_nexthop(mpath, next_hop);
823         mpath->sn = 0xffff;
824         mpath->metric = 0;
825         mpath->hop_count = 0;
826         mpath->exp_time = 0;
827         mpath->flags = MESH_PATH_FIXED | MESH_PATH_SN_VALID;
828         mesh_path_activate(mpath);
829         spin_unlock_bh(&mpath->state_lock);
830         ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg);
831         /* init it at a low value - 0 start is tricky */
832         ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1);
833         mesh_path_tx_pending(mpath);
834 }
835 
836 int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
837 {
838         struct mesh_table *tbl_path, *tbl_mpp;
839         int ret;
840 
841         tbl_path = mesh_table_alloc();
842         if (!tbl_path)
843                 return -ENOMEM;
844 
845         tbl_mpp = mesh_table_alloc();
846         if (!tbl_mpp) {
847                 ret = -ENOMEM;
848                 goto free_path;
849         }
850 
851         rhashtable_init(&tbl_path->rhead, &mesh_rht_params);
852         rhashtable_init(&tbl_mpp->rhead, &mesh_rht_params);
853 
854         sdata->u.mesh.mesh_paths = tbl_path;
855         sdata->u.mesh.mpp_paths = tbl_mpp;
856 
857         return 0;
858 
859 free_path:
860         mesh_table_free(tbl_path);
861         return ret;
862 }
863 
864 static
865 void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
866                           struct mesh_table *tbl)
867 {
868         struct mesh_path *mpath;
869         struct rhashtable_iter iter;
870         int ret;
871 
872         ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_KERNEL);
873         if (ret)
874                 return;
875 
876         ret = rhashtable_walk_start(&iter);
877         if (ret && ret != -EAGAIN)
878                 goto out;
879 
880         while ((mpath = rhashtable_walk_next(&iter))) {
881                 if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
882                         continue;
883                 if (IS_ERR(mpath))
884                         break;
885                 if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
886                     (!(mpath->flags & MESH_PATH_FIXED)) &&
887                      time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
888                         __mesh_path_del(tbl, mpath);
889         }
890 out:
891         rhashtable_walk_stop(&iter);
892         rhashtable_walk_exit(&iter);
893 }
894 
895 void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
896 {
897         mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths);
898         mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths);
899 }
900 
901 void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
902 {
903         mesh_table_free(sdata->u.mesh.mesh_paths);
904         mesh_table_free(sdata->u.mesh.mpp_paths);
905 }
906 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp