2 * Copyright (c) 2008 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
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.
9 #include <linux/kernel.h>
10 #include <linux/random.h>
11 #include "ieee80211_i.h"
15 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
16 #define mpl_dbg(fmt, args...) printk(KERN_DEBUG fmt, ##args)
18 #define mpl_dbg(fmt, args...) do { (void)(0); } while (0)
21 #define PLINK_GET_FRAME_SUBTYPE(p) (p)
22 #define PLINK_GET_LLID(p) (p + 1)
23 #define PLINK_GET_PLID(p) (p + 3)
25 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
26 jiffies + HZ * t / 1000))
28 /* Peer link cancel reasons, all subject to ANA approval */
29 #define MESH_LINK_CANCELLED 2
30 #define MESH_MAX_NEIGHBORS 3
31 #define MESH_CAPABILITY_POLICY_VIOLATION 4
32 #define MESH_CLOSE_RCVD 5
33 #define MESH_MAX_RETRIES 6
34 #define MESH_CONFIRM_TIMEOUT 7
35 #define MESH_SECURITY_ROLE_NEGOTIATION_DIFFERS 8
36 #define MESH_SECURITY_AUTHENTICATION_IMPOSSIBLE 9
37 #define MESH_SECURITY_FAILED_VERIFICATION 10
39 #define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
40 #define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
41 #define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
42 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
43 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
45 enum plink_frame_type {
64 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
66 atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
67 mesh_accept_plinks_update(sdata);
71 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
73 atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
74 mesh_accept_plinks_update(sdata);
78 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
80 * @sta: mes peer link to restart
82 * Locking: this function must be called holding sta->lock
84 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
86 sta->plink_state = PLINK_LISTEN;
87 sta->llid = sta->plid = sta->reason = 0;
88 sta->plink_retries = 0;
92 * NOTE: This is just an alias for sta_info_alloc(), see notes
93 * on it in the lifecycle management section!
95 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
96 u8 *hw_addr, u32 rates)
98 struct ieee80211_local *local = sdata->local;
101 if (local->num_sta >= MESH_MAX_PLINKS)
104 sta = sta_info_alloc(sdata, hw_addr, GFP_ATOMIC);
108 sta->flags = WLAN_STA_AUTHORIZED;
109 sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
110 rate_control_rate_init(sta);
116 * mesh_plink_deactivate - deactivate mesh peer link
118 * @sta: mesh peer link to deactivate
120 * All mesh paths with this peer as next hop will be flushed
122 * Locking: the caller must hold sta->lock
124 static void __mesh_plink_deactivate(struct sta_info *sta)
126 struct ieee80211_sub_if_data *sdata = sta->sdata;
128 if (sta->plink_state == PLINK_ESTAB)
129 mesh_plink_dec_estab_count(sdata);
130 sta->plink_state = PLINK_BLOCKED;
131 mesh_path_flush_by_nexthop(sta);
135 * __mesh_plink_deactivate - deactivate mesh peer link
137 * @sta: mesh peer link to deactivate
139 * All mesh paths with this peer as next hop will be flushed
141 void mesh_plink_deactivate(struct sta_info *sta)
143 spin_lock_bh(&sta->lock);
144 __mesh_plink_deactivate(sta);
145 spin_unlock_bh(&sta->lock);
148 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
149 enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
151 struct ieee80211_local *local = sdata->local;
152 struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
153 struct ieee80211_mgmt *mgmt;
154 bool include_plid = false;
160 skb_reserve(skb, local->hw.extra_tx_headroom);
161 /* 25 is the size of the common mgmt part (24) plus the size of the
162 * common action part (1)
164 mgmt = (struct ieee80211_mgmt *)
165 skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
166 memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
167 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
168 IEEE80211_STYPE_ACTION);
169 memcpy(mgmt->da, da, ETH_ALEN);
170 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
171 /* BSSID is left zeroed, wildcard value */
172 mgmt->u.action.category = PLINK_CATEGORY;
173 mgmt->u.action.u.plink_action.action_code = action;
175 if (action == PLINK_CLOSE)
176 mgmt->u.action.u.plink_action.aux = reason;
178 mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
179 if (action == PLINK_CONFIRM) {
180 pos = skb_put(skb, 4);
181 /* two-byte status code followed by two-byte AID */
184 mesh_mgmt_ies_add(skb, sdata);
187 /* Add Peer Link Management element */
207 pos = skb_put(skb, 2 + ie_len);
208 *pos++ = WLAN_EID_PEER_LINK;
211 memcpy(pos, &llid, 2);
214 memcpy(pos, &plid, 2);
216 if (action == PLINK_CLOSE) {
218 memcpy(pos, &reason, 2);
221 ieee80211_tx_skb(sdata, skb, 1);
225 void mesh_neighbour_update(u8 *hw_addr, u32 rates, struct ieee80211_sub_if_data *sdata,
226 bool peer_accepting_plinks)
228 struct ieee80211_local *local = sdata->local;
229 struct sta_info *sta;
233 sta = sta_info_get(local, hw_addr);
235 sta = mesh_plink_alloc(sdata, hw_addr, rates);
240 if (sta_info_insert(sta)) {
246 sta->last_rx = jiffies;
247 sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
248 if (peer_accepting_plinks && sta->plink_state == PLINK_LISTEN &&
249 sdata->u.mesh.accepting_plinks &&
250 sdata->u.mesh.mshcfg.auto_open_plinks)
251 mesh_plink_open(sta);
256 static void mesh_plink_timer(unsigned long data)
258 struct sta_info *sta;
259 __le16 llid, plid, reason;
260 struct ieee80211_sub_if_data *sdata;
263 * This STA is valid because sta_info_destroy() will
264 * del_timer_sync() this timer after having made sure
265 * it cannot be readded (by deleting the plink.)
267 sta = (struct sta_info *) data;
269 spin_lock_bh(&sta->lock);
270 if (sta->ignore_plink_timer) {
271 sta->ignore_plink_timer = false;
272 spin_unlock_bh(&sta->lock);
275 mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
276 sta->sta.addr, sta->plink_state);
282 switch (sta->plink_state) {
286 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
288 mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
289 sta->sta.addr, sta->plink_retries,
291 get_random_bytes(&rand, sizeof(u32));
292 sta->plink_timeout = sta->plink_timeout +
293 rand % sta->plink_timeout;
294 ++sta->plink_retries;
295 mod_plink_timer(sta, sta->plink_timeout);
296 spin_unlock_bh(&sta->lock);
297 mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
301 reason = cpu_to_le16(MESH_MAX_RETRIES);
302 /* fall through on else */
306 reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
307 sta->plink_state = PLINK_HOLDING;
308 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
309 spin_unlock_bh(&sta->lock);
310 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid, plid,
315 del_timer(&sta->plink_timer);
316 mesh_plink_fsm_restart(sta);
317 spin_unlock_bh(&sta->lock);
320 spin_unlock_bh(&sta->lock);
325 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
327 sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
328 sta->plink_timer.data = (unsigned long) sta;
329 sta->plink_timer.function = mesh_plink_timer;
330 sta->plink_timeout = timeout;
331 add_timer(&sta->plink_timer);
334 int mesh_plink_open(struct sta_info *sta)
337 struct ieee80211_sub_if_data *sdata = sta->sdata;
339 spin_lock_bh(&sta->lock);
340 get_random_bytes(&llid, 2);
342 if (sta->plink_state != PLINK_LISTEN) {
343 spin_unlock_bh(&sta->lock);
346 sta->plink_state = PLINK_OPN_SNT;
347 mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
348 spin_unlock_bh(&sta->lock);
349 mpl_dbg("Mesh plink: starting establishment with %pM\n",
352 return mesh_plink_frame_tx(sdata, PLINK_OPEN,
353 sta->sta.addr, llid, 0, 0);
356 void mesh_plink_block(struct sta_info *sta)
358 spin_lock_bh(&sta->lock);
359 __mesh_plink_deactivate(sta);
360 sta->plink_state = PLINK_BLOCKED;
361 spin_unlock_bh(&sta->lock);
365 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
366 size_t len, struct ieee80211_rx_status *rx_status)
368 struct ieee80211_local *local = sdata->local;
369 struct ieee802_11_elems elems;
370 struct sta_info *sta;
371 enum plink_event event;
372 enum plink_frame_type ftype;
376 __le16 plid, llid, reason;
378 /* need action_code, aux */
379 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
382 if (is_multicast_ether_addr(mgmt->da)) {
383 mpl_dbg("Mesh plink: ignore frame from multicast address");
387 baseaddr = mgmt->u.action.u.plink_action.variable;
388 baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
389 if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
393 ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
394 if (!elems.peer_link) {
395 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
399 ftype = *((u8 *)PLINK_GET_FRAME_SUBTYPE(elems.peer_link));
400 ie_len = elems.peer_link_len;
401 if ((ftype == PLINK_OPEN && ie_len != 3) ||
402 (ftype == PLINK_CONFIRM && ie_len != 5) ||
403 (ftype == PLINK_CLOSE && ie_len != 5 && ie_len != 7)) {
404 mpl_dbg("Mesh plink: incorrect plink ie length\n");
408 if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
409 mpl_dbg("Mesh plink: missing necessary ie\n");
412 /* Note the lines below are correct, the llid in the frame is the plid
413 * from the point of view of this host.
415 memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
416 if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 7))
417 memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
421 sta = sta_info_get(local, mgmt->sa);
422 if (!sta && ftype != PLINK_OPEN) {
423 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
428 if (sta && sta->plink_state == PLINK_BLOCKED) {
433 /* Now we will figure out the appropriate event... */
434 event = PLINK_UNDEFINED;
435 if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
447 spin_lock_bh(&sta->lock);
449 /* ftype == PLINK_OPEN */
451 if (!mesh_plink_free_count(sdata)) {
452 mpl_dbg("Mesh plink error: no more free plinks\n");
457 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
458 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
460 mpl_dbg("Mesh plink error: plink table full\n");
464 if (sta_info_insert(sta)) {
469 spin_lock_bh(&sta->lock);
471 spin_lock_bh(&sta->lock);
474 if (!mesh_plink_free_count(sdata) ||
475 (sta->plid && sta->plid != plid))
481 if (!mesh_plink_free_count(sdata) ||
482 (sta->llid != llid || sta->plid != plid))
488 if (sta->plink_state == PLINK_ESTAB)
489 /* Do not check for llid or plid. This does not
490 * follow the standard but since multiple plinks
491 * per sta are not supported, it is necessary in
492 * order to avoid a livelock when MP A sees an
493 * establish peer link to MP B but MP B does not
494 * see it. This can be caused by a timeout in
495 * B's peer link establishment or B beign
499 else if (sta->plid != plid)
501 else if (ie_len == 7 && sta->llid != llid)
507 mpl_dbg("Mesh plink: unknown frame subtype\n");
508 spin_unlock_bh(&sta->lock);
514 mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %d %d %d %d\n",
515 mgmt->sa, sta->plink_state,
516 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
519 switch (sta->plink_state) {
520 /* spin_unlock as soon as state is updated at each case */
524 mesh_plink_fsm_restart(sta);
525 spin_unlock_bh(&sta->lock);
528 sta->plink_state = PLINK_OPN_RCVD;
530 get_random_bytes(&llid, 2);
532 mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
533 spin_unlock_bh(&sta->lock);
534 mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
536 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
540 spin_unlock_bh(&sta->lock);
549 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
552 reason = cpu_to_le16(MESH_CLOSE_RCVD);
553 sta->reason = reason;
554 sta->plink_state = PLINK_HOLDING;
555 if (!mod_plink_timer(sta,
556 dot11MeshHoldingTimeout(sdata)))
557 sta->ignore_plink_timer = true;
560 spin_unlock_bh(&sta->lock);
561 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
565 /* retry timer is left untouched */
566 sta->plink_state = PLINK_OPN_RCVD;
569 spin_unlock_bh(&sta->lock);
570 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
574 sta->plink_state = PLINK_CNF_RCVD;
575 if (!mod_plink_timer(sta,
576 dot11MeshConfirmTimeout(sdata)))
577 sta->ignore_plink_timer = true;
579 spin_unlock_bh(&sta->lock);
582 spin_unlock_bh(&sta->lock);
591 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
594 reason = cpu_to_le16(MESH_CLOSE_RCVD);
595 sta->reason = reason;
596 sta->plink_state = PLINK_HOLDING;
597 if (!mod_plink_timer(sta,
598 dot11MeshHoldingTimeout(sdata)))
599 sta->ignore_plink_timer = true;
602 spin_unlock_bh(&sta->lock);
603 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
608 spin_unlock_bh(&sta->lock);
609 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
613 del_timer(&sta->plink_timer);
614 sta->plink_state = PLINK_ESTAB;
615 mesh_plink_inc_estab_count(sdata);
616 spin_unlock_bh(&sta->lock);
617 mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
621 spin_unlock_bh(&sta->lock);
630 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
633 reason = cpu_to_le16(MESH_CLOSE_RCVD);
634 sta->reason = reason;
635 sta->plink_state = PLINK_HOLDING;
636 if (!mod_plink_timer(sta,
637 dot11MeshHoldingTimeout(sdata)))
638 sta->ignore_plink_timer = true;
641 spin_unlock_bh(&sta->lock);
642 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
646 del_timer(&sta->plink_timer);
647 sta->plink_state = PLINK_ESTAB;
648 mesh_plink_inc_estab_count(sdata);
649 spin_unlock_bh(&sta->lock);
650 mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
652 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
656 spin_unlock_bh(&sta->lock);
664 reason = cpu_to_le16(MESH_CLOSE_RCVD);
665 sta->reason = reason;
666 __mesh_plink_deactivate(sta);
667 sta->plink_state = PLINK_HOLDING;
669 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
670 spin_unlock_bh(&sta->lock);
671 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
676 spin_unlock_bh(&sta->lock);
677 mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
681 spin_unlock_bh(&sta->lock);
688 if (del_timer(&sta->plink_timer))
689 sta->ignore_plink_timer = 1;
690 mesh_plink_fsm_restart(sta);
691 spin_unlock_bh(&sta->lock);
698 reason = sta->reason;
699 spin_unlock_bh(&sta->lock);
700 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
704 spin_unlock_bh(&sta->lock);
708 /* should not get here, PLINK_BLOCKED is dealt with at the
709 * beggining of the function
711 spin_unlock_bh(&sta->lock);