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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++ = MESH_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 | action == MPATH_PREQ && |
395 | new_metric >= mpath->metric)) { |
396 | process = false; |
397 | fresh_info = false; |
398 | } |
399 | } |
400 | } else { |
401 | mesh_path_add(orig_addr, sdata); |
402 | mpath = mesh_path_lookup(orig_addr, sdata); |
403 | if (!mpath) { |
404 | rcu_read_unlock(); |
405 | return 0; |
406 | } |
407 | spin_lock_bh(&mpath->state_lock); |
408 | } |
409 | |
410 | if (fresh_info) { |
411 | mesh_path_assign_nexthop(mpath, sta); |
412 | mpath->flags |= MESH_PATH_SN_VALID; |
413 | mpath->metric = new_metric; |
414 | mpath->sn = orig_sn; |
415 | mpath->exp_time = time_after(mpath->exp_time, exp_time) |
416 | ? mpath->exp_time : exp_time; |
417 | mesh_path_activate(mpath); |
418 | spin_unlock_bh(&mpath->state_lock); |
419 | mesh_path_tx_pending(mpath); |
420 | /* draft says preq_id should be saved to, but there does |
421 | * not seem to be any use for it, skipping by now |
422 | */ |
423 | } else |
424 | spin_unlock_bh(&mpath->state_lock); |
425 | } |
426 | |
427 | /* Update and check transmitter routing info */ |
428 | ta = mgmt->sa; |
429 | if (memcmp(orig_addr, ta, ETH_ALEN) == 0) |
430 | fresh_info = false; |
431 | else { |
432 | fresh_info = true; |
433 | |
434 | mpath = mesh_path_lookup(ta, sdata); |
435 | if (mpath) { |
436 | spin_lock_bh(&mpath->state_lock); |
437 | if ((mpath->flags & MESH_PATH_FIXED) || |
438 | ((mpath->flags & MESH_PATH_ACTIVE) && |
439 | (last_hop_metric > mpath->metric))) |
440 | fresh_info = false; |
441 | } else { |
442 | mesh_path_add(ta, sdata); |
443 | mpath = mesh_path_lookup(ta, sdata); |
444 | if (!mpath) { |
445 | rcu_read_unlock(); |
446 | return 0; |
447 | } |
448 | spin_lock_bh(&mpath->state_lock); |
449 | } |
450 | |
451 | if (fresh_info) { |
452 | mesh_path_assign_nexthop(mpath, sta); |
453 | mpath->flags &= ~MESH_PATH_SN_VALID; |
454 | mpath->metric = last_hop_metric; |
455 | mpath->exp_time = time_after(mpath->exp_time, exp_time) |
456 | ? mpath->exp_time : exp_time; |
457 | mesh_path_activate(mpath); |
458 | spin_unlock_bh(&mpath->state_lock); |
459 | mesh_path_tx_pending(mpath); |
460 | } else |
461 | spin_unlock_bh(&mpath->state_lock); |
462 | } |
463 | |
464 | rcu_read_unlock(); |
465 | |
466 | return process ? new_metric : 0; |
467 | } |
468 | |
469 | static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, |
470 | struct ieee80211_mgmt *mgmt, |
471 | u8 *preq_elem, u32 metric) |
472 | { |
473 | struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; |
474 | struct mesh_path *mpath; |
475 | u8 *target_addr, *orig_addr; |
476 | u8 target_flags, ttl; |
477 | u32 orig_sn, target_sn, lifetime; |
478 | bool reply = false; |
479 | bool forward = true; |
480 | |
481 | /* Update target SN, if present */ |
482 | target_addr = PREQ_IE_TARGET_ADDR(preq_elem); |
483 | orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); |
484 | target_sn = PREQ_IE_TARGET_SN(preq_elem); |
485 | orig_sn = PREQ_IE_ORIG_SN(preq_elem); |
486 | target_flags = PREQ_IE_TARGET_F(preq_elem); |
487 | |
488 | mhwmp_dbg("received PREQ from %pM\n", orig_addr); |
489 | |
490 | if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) { |
491 | mhwmp_dbg("PREQ is for us\n"); |
492 | forward = false; |
493 | reply = true; |
494 | metric = 0; |
495 | if (time_after(jiffies, ifmsh->last_sn_update + |
496 | net_traversal_jiffies(sdata)) || |
497 | time_before(jiffies, ifmsh->last_sn_update)) { |
498 | target_sn = ++ifmsh->sn; |
499 | ifmsh->last_sn_update = jiffies; |
500 | } |
501 | } else { |
502 | rcu_read_lock(); |
503 | mpath = mesh_path_lookup(target_addr, sdata); |
504 | if (mpath) { |
505 | if ((!(mpath->flags & MESH_PATH_SN_VALID)) || |
506 | SN_LT(mpath->sn, target_sn)) { |
507 | mpath->sn = target_sn; |
508 | mpath->flags |= MESH_PATH_SN_VALID; |
509 | } else if ((!(target_flags & MP_F_DO)) && |
510 | (mpath->flags & MESH_PATH_ACTIVE)) { |
511 | reply = true; |
512 | metric = mpath->metric; |
513 | target_sn = mpath->sn; |
514 | if (target_flags & MP_F_RF) |
515 | target_flags |= MP_F_DO; |
516 | else |
517 | forward = false; |
518 | } |
519 | } |
520 | rcu_read_unlock(); |
521 | } |
522 | |
523 | if (reply) { |
524 | lifetime = PREQ_IE_LIFETIME(preq_elem); |
525 | ttl = ifmsh->mshcfg.dot11MeshTTL; |
526 | if (ttl != 0) { |
527 | mhwmp_dbg("replying to the PREQ\n"); |
528 | mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr, |
529 | cpu_to_le32(target_sn), 0, orig_addr, |
530 | cpu_to_le32(orig_sn), mgmt->sa, 0, ttl, |
531 | cpu_to_le32(lifetime), cpu_to_le32(metric), |
532 | 0, sdata); |
533 | } else |
534 | ifmsh->mshstats.dropped_frames_ttl++; |
535 | } |
536 | |
537 | if (forward) { |
538 | u32 preq_id; |
539 | u8 hopcount, flags; |
540 | |
541 | ttl = PREQ_IE_TTL(preq_elem); |
542 | lifetime = PREQ_IE_LIFETIME(preq_elem); |
543 | if (ttl <= 1) { |
544 | ifmsh->mshstats.dropped_frames_ttl++; |
545 | return; |
546 | } |
547 | mhwmp_dbg("forwarding the PREQ from %pM\n", orig_addr); |
548 | --ttl; |
549 | flags = PREQ_IE_FLAGS(preq_elem); |
550 | preq_id = PREQ_IE_PREQ_ID(preq_elem); |
551 | hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; |
552 | mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, |
553 | cpu_to_le32(orig_sn), target_flags, target_addr, |
554 | cpu_to_le32(target_sn), broadcast_addr, |
555 | hopcount, ttl, cpu_to_le32(lifetime), |
556 | cpu_to_le32(metric), cpu_to_le32(preq_id), |
557 | sdata); |
558 | ifmsh->mshstats.fwded_mcast++; |
559 | ifmsh->mshstats.fwded_frames++; |
560 | } |
561 | } |
562 | |
563 | |
564 | static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, |
565 | struct ieee80211_mgmt *mgmt, |
566 | u8 *prep_elem, u32 metric) |
567 | { |
568 | struct mesh_path *mpath; |
569 | u8 *target_addr, *orig_addr; |
570 | u8 ttl, hopcount, flags; |
571 | u8 next_hop[ETH_ALEN]; |
572 | u32 target_sn, orig_sn, lifetime; |
573 | |
574 | mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem)); |
575 | |
576 | /* Note that we divert from the draft nomenclature and denominate |
577 | * destination to what the draft refers to as origininator. So in this |
578 | * function destnation refers to the final destination of the PREP, |
579 | * which corresponds with the originator of the PREQ which this PREP |
580 | * replies |
581 | */ |
582 | target_addr = PREP_IE_TARGET_ADDR(prep_elem); |
583 | if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) |
584 | /* destination, no forwarding required */ |
585 | return; |
586 | |
587 | ttl = PREP_IE_TTL(prep_elem); |
588 | if (ttl <= 1) { |
589 | sdata->u.mesh.mshstats.dropped_frames_ttl++; |
590 | return; |
591 | } |
592 | |
593 | rcu_read_lock(); |
594 | mpath = mesh_path_lookup(target_addr, sdata); |
595 | if (mpath) |
596 | spin_lock_bh(&mpath->state_lock); |
597 | else |
598 | goto fail; |
599 | if (!(mpath->flags & MESH_PATH_ACTIVE)) { |
600 | spin_unlock_bh(&mpath->state_lock); |
601 | goto fail; |
602 | } |
603 | memcpy(next_hop, mpath->next_hop->sta.addr, ETH_ALEN); |
604 | spin_unlock_bh(&mpath->state_lock); |
605 | --ttl; |
606 | flags = PREP_IE_FLAGS(prep_elem); |
607 | lifetime = PREP_IE_LIFETIME(prep_elem); |
608 | hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; |
609 | orig_addr = PREP_IE_ORIG_ADDR(prep_elem); |
610 | target_sn = PREP_IE_TARGET_SN(prep_elem); |
611 | orig_sn = PREP_IE_ORIG_SN(prep_elem); |
612 | |
613 | mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, |
614 | cpu_to_le32(orig_sn), 0, target_addr, |
615 | cpu_to_le32(target_sn), next_hop, hopcount, |
616 | ttl, cpu_to_le32(lifetime), cpu_to_le32(metric), |
617 | 0, sdata); |
618 | rcu_read_unlock(); |
619 | |
620 | sdata->u.mesh.mshstats.fwded_unicast++; |
621 | sdata->u.mesh.mshstats.fwded_frames++; |
622 | return; |
623 | |
624 | fail: |
625 | rcu_read_unlock(); |
626 | sdata->u.mesh.mshstats.dropped_frames_no_route++; |
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, &sdata->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, &sdata->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->vif.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->vif.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->vif.addr, |
1014 | cpu_to_le32(++ifmsh->sn), |
1015 | 0, NULL, 0, broadcast_addr, |
1016 | 0, MESH_TTL, 0, 0, 0, sdata); |
1017 | } |
1018 |
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javiroman/ks7010
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9