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[openwrt/svn-archive/archive.git] / package / wprobe / src / kernel / wprobe-core.c
1 /*
2 * wprobe-core.c: Wireless probe interface core
3 * Copyright (C) 2008-2009 Felix Fietkau <nbd@openwrt.org>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/version.h>
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/spinlock.h>
21 #include <linux/rcupdate.h>
22 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
23 #include <linux/rculist.h>
24 #else
25 #include <linux/list.h>
26 #endif
27 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0)
28 #include <linux/prefetch.h>
29 #endif
30 #include <linux/skbuff.h>
31 #include <linux/wprobe.h>
32 #include <linux/math64.h>
33
34 #define static
35
36 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,28)
37 #define list_for_each_rcu(pos, head) \
38 for (pos = rcu_dereference((head)->next); \
39 prefetch(pos->next), pos != (head); \
40 pos = rcu_dereference(pos->next))
41 #endif
42
43 #define WPROBE_MIN_INTERVAL 100 /* minimum measurement interval in msecs */
44 #define WPROBE_MAX_FILTER_SIZE 1024
45 #define WPROBE_MAX_FRAME_SIZE 1900
46
47 static struct list_head wprobe_if;
48 static spinlock_t wprobe_lock;
49
50 static struct genl_family wprobe_fam = {
51 .id = GENL_ID_GENERATE,
52 .name = "wprobe",
53 .hdrsize = 0,
54 .version = 1,
55 /* only the first set of attributes is used for queries */
56 .maxattr = WPROBE_ATTR_LAST,
57 };
58
59 /* fake radiotap header */
60 struct wprobe_rtap_hdr {
61 __u8 version;
62 __u8 padding;
63 __le16 len;
64 __le32 present;
65 };
66
67 static void wprobe_update_stats(struct wprobe_iface *dev, struct wprobe_link *l);
68 static int wprobe_sync_data(struct wprobe_iface *dev, struct wprobe_link *l, bool query);
69 static void wprobe_free_filter(struct wprobe_filter *f);
70
71 int
72 wprobe_add_link(struct wprobe_iface *s, struct wprobe_link *l, const char *addr)
73 {
74 unsigned long flags;
75
76 INIT_LIST_HEAD(&l->list);
77 l->val = kzalloc(sizeof(struct wprobe_value) * s->n_link_items, GFP_ATOMIC);
78 if (!l->val)
79 return -ENOMEM;
80
81 l->iface = s;
82 memcpy(&l->addr, addr, ETH_ALEN);
83 spin_lock_irqsave(&wprobe_lock, flags);
84 list_add_tail_rcu(&l->list, &s->links);
85 spin_unlock_irqrestore(&wprobe_lock, flags);
86
87 return 0;
88 }
89 EXPORT_SYMBOL(wprobe_add_link);
90
91 void
92 wprobe_remove_link(struct wprobe_iface *s, struct wprobe_link *l)
93 {
94 unsigned long flags;
95
96 spin_lock_irqsave(&wprobe_lock, flags);
97 list_del_rcu(&l->list);
98 spin_unlock_irqrestore(&wprobe_lock, flags);
99 synchronize_rcu();
100 kfree(l->val);
101 }
102 EXPORT_SYMBOL(wprobe_remove_link);
103
104 static void
105 wprobe_measure_timer(unsigned long data)
106 {
107 struct wprobe_iface *dev = (struct wprobe_iface *) data;
108
109 /* set next measurement interval */
110 mod_timer(&dev->measure_timer, jiffies +
111 msecs_to_jiffies(dev->measure_interval));
112
113 /* perform measurement */
114 wprobe_sync_data(dev, NULL, false);
115 }
116
117 int
118 wprobe_add_iface(struct wprobe_iface *s)
119 {
120 unsigned long flags;
121 int vsize;
122
123 /* reset only wprobe private area */
124 memset(&s->list, 0, sizeof(struct wprobe_iface) - offsetof(struct wprobe_iface, list));
125
126 BUG_ON(!s->name);
127 INIT_LIST_HEAD(&s->list);
128 INIT_LIST_HEAD(&s->links);
129 setup_timer(&s->measure_timer, wprobe_measure_timer, (unsigned long) s);
130
131 s->val = kzalloc(sizeof(struct wprobe_value) * s->n_global_items, GFP_ATOMIC);
132 if (!s->val)
133 goto error;
134
135 vsize = max(s->n_link_items, s->n_global_items);
136 s->query_val = kzalloc(sizeof(struct wprobe_value) * vsize, GFP_ATOMIC);
137 if (!s->query_val)
138 goto error;
139
140 /* initialize defaults to be able to handle overflow,
141 * user space will need to handle this if it keeps an
142 * internal histogram */
143 s->scale_min = 20;
144 s->scale_max = (1 << 31);
145
146 s->scale_m = 1;
147 s->scale_d = 10;
148
149 spin_lock_irqsave(&wprobe_lock, flags);
150 list_add_rcu(&s->list, &wprobe_if);
151 spin_unlock_irqrestore(&wprobe_lock, flags);
152
153 return 0;
154
155 error:
156 if (s->val)
157 kfree(s->val);
158 return -ENOMEM;
159 }
160 EXPORT_SYMBOL(wprobe_add_iface);
161
162 void
163 wprobe_remove_iface(struct wprobe_iface *s)
164 {
165 unsigned long flags;
166
167 BUG_ON(!list_empty(&s->links));
168
169 del_timer_sync(&s->measure_timer);
170 spin_lock_irqsave(&wprobe_lock, flags);
171 list_del_rcu(&s->list);
172 spin_unlock_irqrestore(&wprobe_lock, flags);
173
174 /* wait for all queries to finish before freeing the
175 * temporary value storage buffer */
176 synchronize_rcu();
177
178 kfree(s->val);
179 kfree(s->query_val);
180 if (s->active_filter)
181 wprobe_free_filter(s->active_filter);
182 }
183 EXPORT_SYMBOL(wprobe_remove_iface);
184
185 static struct wprobe_iface *
186 wprobe_get_dev(struct nlattr *attr)
187 {
188 struct wprobe_iface *dev = NULL;
189 struct wprobe_iface *p;
190 const char *name;
191 int i = 0;
192
193 if (!attr)
194 return NULL;
195
196 name = nla_data(attr);
197 list_for_each_entry_rcu(p, &wprobe_if, list) {
198 i++;
199 if (strcmp(name, p->name) != 0)
200 continue;
201
202 dev = p;
203 break;
204 }
205
206 return dev;
207 }
208
209 int
210 wprobe_add_frame(struct wprobe_iface *dev, const struct wprobe_wlan_hdr *hdr, void *data, int len)
211 {
212 struct wprobe_wlan_hdr *new_hdr;
213 struct wprobe_filter *f;
214 struct sk_buff *skb;
215 unsigned long flags;
216 int i, j;
217
218 rcu_read_lock();
219 f = rcu_dereference(dev->active_filter);
220 if (!f)
221 goto out;
222
223 spin_lock_irqsave(&f->lock, flags);
224
225 skb = f->skb;
226 skb->len = sizeof(struct wprobe_rtap_hdr);
227 skb->tail = skb->data + skb->len;
228 if (len + skb->len > WPROBE_MAX_FRAME_SIZE)
229 len = WPROBE_MAX_FRAME_SIZE - skb->len;
230
231 new_hdr = (struct wprobe_wlan_hdr *) skb_put(skb, f->hdrlen);
232 memcpy(new_hdr, hdr, sizeof(struct wprobe_wlan_hdr));
233 new_hdr->len = cpu_to_be16(new_hdr->len);
234
235 memcpy(skb_put(skb, len), data, len);
236
237 for(i = 0; i < f->n_groups; i++) {
238 struct wprobe_filter_group *fg = &f->groups[i];
239 bool found = false;
240 int def = -1;
241
242 for (j = 0; j < fg->n_items; j++) {
243 struct wprobe_filter_item *fi = fg->items[j];
244
245 if (!fi->hdr.n_items) {
246 def = j;
247 continue;
248 }
249 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,38)
250 if (sk_run_filter(skb, fi->filter) == 0)
251 continue;
252 #else
253 if (sk_run_filter(skb, fi->filter, fi->hdr.n_items) == 0)
254 continue;
255 #endif
256
257 found = true;
258 break;
259 }
260 if (!found && def >= 0) {
261 j = def;
262 found = true;
263 }
264 if (found) {
265 struct wprobe_filter_counter *c = &fg->counters[j];
266
267 if (hdr->type >= WPROBE_PKT_TX)
268 c->tx++;
269 else
270 c->rx++;
271 }
272 }
273
274 spin_unlock_irqrestore(&f->lock, flags);
275 out:
276 rcu_read_unlock();
277 return 0;
278 }
279 EXPORT_SYMBOL(wprobe_add_frame);
280
281 static int
282 wprobe_sync_data(struct wprobe_iface *dev, struct wprobe_link *l, bool query)
283 {
284 struct wprobe_value *val;
285 unsigned long flags;
286 int n, err;
287
288 if (l) {
289 n = dev->n_link_items;
290 val = l->val;
291 } else {
292 n = dev->n_global_items;
293 val = dev->val;
294 }
295
296 spin_lock_irqsave(&dev->lock, flags);
297 err = dev->sync_data(dev, l, val, !query);
298 if (err)
299 goto done;
300
301 if (query)
302 memcpy(dev->query_val, val, sizeof(struct wprobe_value) * n);
303
304 wprobe_update_stats(dev, l);
305 done:
306 spin_unlock_irqrestore(&dev->lock, flags);
307 return 0;
308 }
309 EXPORT_SYMBOL(wprobe_sync_data);
310
311 static void
312 wprobe_scale_stats(struct wprobe_iface *dev, const struct wprobe_item *item,
313 struct wprobe_value *val, int n)
314 {
315 u64 scale_ts = jiffies_64;
316 int i;
317
318 for (i = 0; i < n; i++) {
319 if (!(item[i].flags & WPROBE_F_KEEPSTAT))
320 continue;
321
322 if (val[i].n <= dev->scale_min)
323 continue;
324
325 /* FIXME: div_s64 seems to be very imprecise here, even when
326 * the values are scaled up */
327 val[i].s *= dev->scale_m;
328 val[i].s = div_s64(val[i].s, dev->scale_d);
329
330 val[i].ss *= dev->scale_m;
331 val[i].ss = div_s64(val[i].ss, dev->scale_d);
332
333 val[i].n = (val[i].n * dev->scale_m) / dev->scale_d;
334 val[i].scale_timestamp = scale_ts;
335 }
336 }
337
338
339 void
340 wprobe_update_stats(struct wprobe_iface *dev, struct wprobe_link *l)
341 {
342 const struct wprobe_item *item;
343 struct wprobe_value *val;
344 bool scale_stats = false;
345 int i, n;
346
347 if (l) {
348 n = dev->n_link_items;
349 item = dev->link_items;
350 val = l->val;
351 } else {
352 n = dev->n_global_items;
353 item = dev->global_items;
354 val = dev->val;
355 }
356
357 /* process statistics */
358 for (i = 0; i < n; i++) {
359 s64 v;
360
361 if (!val[i].pending)
362 continue;
363
364 val[i].n++;
365 if ((item[i].flags & WPROBE_F_KEEPSTAT) &&
366 (dev->scale_max > 0) && (val[i].n > dev->scale_max)) {
367 scale_stats = true;
368 }
369
370 switch(item[i].type) {
371 case WPROBE_VAL_S8:
372 v = val[i].S8;
373 break;
374 case WPROBE_VAL_S16:
375 v = val[i].S16;
376 break;
377 case WPROBE_VAL_S32:
378 v = val[i].S32;
379 break;
380 case WPROBE_VAL_S64:
381 v = val[i].S64;
382 break;
383 case WPROBE_VAL_U8:
384 v = val[i].U8;
385 break;
386 case WPROBE_VAL_U16:
387 v = val[i].U16;
388 break;
389 case WPROBE_VAL_U32:
390 v = val[i].U32;
391 break;
392 case WPROBE_VAL_U64:
393 v = val[i].U64;
394 break;
395 default:
396 continue;
397 }
398
399 val[i].s += v;
400 val[i].ss += v * v;
401 val[i].pending = false;
402 }
403 if (scale_stats)
404 wprobe_scale_stats(dev, item, val, n);
405 }
406 EXPORT_SYMBOL(wprobe_update_stats);
407
408 static const struct nla_policy wprobe_policy[WPROBE_ATTR_LAST+1] = {
409 [WPROBE_ATTR_INTERFACE] = { .type = NLA_NUL_STRING },
410 [WPROBE_ATTR_MAC] = { .type = NLA_STRING },
411 [WPROBE_ATTR_FLAGS] = { .type = NLA_U32 },
412
413 /* config */
414 [WPROBE_ATTR_INTERVAL] = { .type = NLA_MSECS },
415 [WPROBE_ATTR_SAMPLES_MIN] = { .type = NLA_U32 },
416 [WPROBE_ATTR_SAMPLES_MAX] = { .type = NLA_U32 },
417 [WPROBE_ATTR_SAMPLES_SCALE_M] = { .type = NLA_U32 },
418 [WPROBE_ATTR_SAMPLES_SCALE_D] = { .type = NLA_U32 },
419 [WPROBE_ATTR_FILTER] = { .type = NLA_BINARY, .len = 32768 },
420 };
421
422 static bool
423 wprobe_check_ptr(struct list_head *list, struct list_head *ptr)
424 {
425 struct list_head *p;
426
427 list_for_each_rcu(p, list) {
428 if (ptr == p)
429 return true;
430 }
431 return false;
432 }
433
434 static bool
435 wprobe_send_item_value(struct sk_buff *msg, struct netlink_callback *cb,
436 struct wprobe_iface *dev, struct wprobe_link *l,
437 const struct wprobe_item *item,
438 int i, u32 flags)
439 {
440 struct genlmsghdr *hdr;
441 struct wprobe_value *val = dev->query_val;
442 u64 time = val[i].last - val[i].first;
443
444 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
445 &wprobe_fam, NLM_F_MULTI, WPROBE_CMD_GET_INFO);
446
447 NLA_PUT_U32(msg, WPROBE_ATTR_ID, i);
448 NLA_PUT_U32(msg, WPROBE_ATTR_FLAGS, flags);
449 NLA_PUT_U8(msg, WPROBE_ATTR_TYPE, item[i].type);
450 NLA_PUT_U64(msg, WPROBE_ATTR_DURATION, time);
451
452 switch(item[i].type) {
453 case WPROBE_VAL_S8:
454 case WPROBE_VAL_U8:
455 NLA_PUT_U8(msg, item[i].type, val[i].U8);
456 break;
457 case WPROBE_VAL_S16:
458 case WPROBE_VAL_U16:
459 NLA_PUT_U16(msg, item[i].type, val[i].U16);
460 break;
461 case WPROBE_VAL_S32:
462 case WPROBE_VAL_U32:
463 NLA_PUT_U32(msg, item[i].type, val[i].U32);
464 break;
465 case WPROBE_VAL_S64:
466 case WPROBE_VAL_U64:
467 NLA_PUT_U64(msg, item[i].type, val[i].U64);
468 break;
469 case WPROBE_VAL_STRING:
470 if (val[i].STRING)
471 NLA_PUT_STRING(msg, item[i].type, val[i].STRING);
472 else
473 NLA_PUT_STRING(msg, item[i].type, "");
474 /* bypass avg/stdev */
475 goto done;
476 default:
477 /* skip unknown values */
478 goto done;
479 }
480 if (item[i].flags & WPROBE_F_KEEPSTAT) {
481 NLA_PUT_U64(msg, WPROBE_VAL_SUM, val[i].s);
482 NLA_PUT_U64(msg, WPROBE_VAL_SUM_SQ, val[i].ss);
483 NLA_PUT_U32(msg, WPROBE_VAL_SAMPLES, (u32) val[i].n);
484 NLA_PUT_MSECS(msg, WPROBE_VAL_SCALE_TIME, val[i].scale_timestamp);
485 }
486 done:
487 genlmsg_end(msg, hdr);
488 return true;
489
490 nla_put_failure:
491 genlmsg_cancel(msg, hdr);
492 return false;
493 }
494
495 static bool
496 wprobe_send_item_info(struct sk_buff *msg, struct netlink_callback *cb,
497 struct wprobe_iface *dev,
498 const struct wprobe_item *item, int i)
499 {
500 struct genlmsghdr *hdr;
501
502 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
503 &wprobe_fam, NLM_F_MULTI, WPROBE_CMD_GET_LIST);
504
505 if ((i == 0) && (dev->addr != NULL))
506 NLA_PUT(msg, WPROBE_ATTR_MAC, 6, dev->addr);
507 NLA_PUT_U32(msg, WPROBE_ATTR_ID, (u32) i);
508 NLA_PUT_STRING(msg, WPROBE_ATTR_NAME, item[i].name);
509 NLA_PUT_U8(msg, WPROBE_ATTR_TYPE, item[i].type);
510 NLA_PUT_U32(msg, WPROBE_ATTR_FLAGS, item[i].flags);
511 genlmsg_end(msg, hdr);
512 return true;
513
514 nla_put_failure:
515 genlmsg_cancel(msg, hdr);
516 return false;
517 }
518
519
520 static struct wprobe_link *
521 wprobe_find_link(struct wprobe_iface *dev, const char *mac)
522 {
523 struct wprobe_link *l;
524
525 list_for_each_entry_rcu(l, &dev->links, list) {
526 if (!memcmp(l->addr, mac, 6))
527 return l;
528 }
529 return NULL;
530 }
531
532 static bool
533 wprobe_dump_filter_group(struct sk_buff *msg, struct wprobe_filter_group *fg, struct netlink_callback *cb)
534 {
535 struct genlmsghdr *hdr;
536 struct nlattr *group, *item;
537 int i;
538
539 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
540 &wprobe_fam, NLM_F_MULTI, WPROBE_CMD_GET_FILTER);
541 if (!hdr)
542 return false;
543
544 NLA_PUT_STRING(msg, WPROBE_ATTR_NAME, fg->name);
545 group = nla_nest_start(msg, WPROBE_ATTR_FILTER_GROUP);
546 for (i = 0; i < fg->n_items; i++) {
547 struct wprobe_filter_item *fi = fg->items[i];
548 struct wprobe_filter_counter *fc = &fg->counters[i];
549
550 item = nla_nest_start(msg, WPROBE_ATTR_FILTER_GROUP);
551 NLA_PUT_STRING(msg, WPROBE_ATTR_NAME, fi->hdr.name);
552 NLA_PUT_U64(msg, WPROBE_ATTR_RXCOUNT, fc->rx);
553 NLA_PUT_U64(msg, WPROBE_ATTR_TXCOUNT, fc->tx);
554 nla_nest_end(msg, item);
555 }
556
557 nla_nest_end(msg, group);
558 genlmsg_end(msg, hdr);
559 return true;
560
561 nla_put_failure:
562 genlmsg_cancel(msg, hdr);
563 return false;
564 }
565
566 static int
567 wprobe_dump_filters(struct sk_buff *skb, struct netlink_callback *cb)
568 {
569 struct wprobe_iface *dev = (struct wprobe_iface *)cb->args[0];
570 struct wprobe_filter *f;
571 int err = 0;
572 int i = 0;
573
574 if (!dev) {
575 err = nlmsg_parse(cb->nlh, GENL_HDRLEN + wprobe_fam.hdrsize,
576 wprobe_fam.attrbuf, wprobe_fam.maxattr, wprobe_policy);
577 if (err)
578 goto done;
579
580 dev = wprobe_get_dev(wprobe_fam.attrbuf[WPROBE_ATTR_INTERFACE]);
581 if (!dev) {
582 err = -ENODEV;
583 goto done;
584 }
585
586 cb->args[0] = (long) dev;
587 cb->args[1] = 0;
588 } else {
589 if (!wprobe_check_ptr(&wprobe_if, &dev->list)) {
590 err = -ENODEV;
591 goto done;
592 }
593 }
594
595 rcu_read_lock();
596 f = rcu_dereference(dev->active_filter);
597 if (!f)
598 goto abort;
599
600 for (i = cb->args[1]; i < f->n_groups; i++) {
601 if (unlikely(!wprobe_dump_filter_group(skb, &f->groups[i], cb)))
602 break;
603 }
604 cb->args[1] = i;
605 abort:
606 rcu_read_unlock();
607 err = skb->len;
608 done:
609 return err;
610 }
611
612 static bool
613 wprobe_dump_link(struct sk_buff *msg, struct wprobe_link *l, struct netlink_callback *cb)
614 {
615 struct genlmsghdr *hdr;
616
617 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
618 &wprobe_fam, NLM_F_MULTI, WPROBE_CMD_GET_LINKS);
619 if (!hdr)
620 return false;
621
622 NLA_PUT(msg, WPROBE_ATTR_MAC, 6, l->addr);
623 genlmsg_end(msg, hdr);
624 return true;
625
626 nla_put_failure:
627 genlmsg_cancel(msg, hdr);
628 return false;
629 }
630
631 static int
632 wprobe_dump_links(struct sk_buff *skb, struct netlink_callback *cb)
633 {
634 struct wprobe_iface *dev = (struct wprobe_iface *)cb->args[0];
635 struct wprobe_link *l;
636 int err = 0;
637 int i = 0;
638
639 if (!dev) {
640 err = nlmsg_parse(cb->nlh, GENL_HDRLEN + wprobe_fam.hdrsize,
641 wprobe_fam.attrbuf, wprobe_fam.maxattr, wprobe_policy);
642 if (err)
643 goto done;
644
645 dev = wprobe_get_dev(wprobe_fam.attrbuf[WPROBE_ATTR_INTERFACE]);
646 if (!dev) {
647 err = -ENODEV;
648 goto done;
649 }
650
651 cb->args[0] = (long) dev;
652 } else {
653 if (!wprobe_check_ptr(&wprobe_if, &dev->list)) {
654 err = -ENODEV;
655 goto done;
656 }
657 }
658
659 rcu_read_lock();
660 list_for_each_entry_rcu(l, &dev->links, list) {
661 if (i < cb->args[1])
662 continue;
663
664 if (unlikely(!wprobe_dump_link(skb, l, cb)))
665 break;
666
667 i++;
668 }
669 cb->args[1] = i;
670 rcu_read_unlock();
671 err = skb->len;
672 done:
673 return err;
674 }
675
676 #define WPROBE_F_LINK (1 << 31) /* for internal use */
677 static int
678 wprobe_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
679 {
680 struct wprobe_iface *dev = (struct wprobe_iface *)cb->args[0];
681 struct wprobe_link *l = (struct wprobe_link *)cb->args[1];
682 struct wprobe_value *val;
683 const struct wprobe_item *item;
684 struct genlmsghdr *hdr;
685 unsigned long flags;
686 int cmd, n, i = cb->args[3];
687 u32 vflags = cb->args[2];
688 int err = 0;
689
690 hdr = (struct genlmsghdr *)nlmsg_data(cb->nlh);
691 cmd = hdr->cmd;
692
693 /* since the attribute value list might be too big for a single netlink
694 * message, the device, link and offset get stored in the netlink callback.
695 * if this is the first request, we need to do the full lookup for the device.
696 *
697 * access to the device and link structure is synchronized through rcu.
698 */
699 rcu_read_lock();
700 if (!dev) {
701 err = nlmsg_parse(cb->nlh, GENL_HDRLEN + wprobe_fam.hdrsize,
702 wprobe_fam.attrbuf, wprobe_fam.maxattr, wprobe_policy);
703 if (err)
704 goto done;
705
706 err = -ENOENT;
707 dev = wprobe_get_dev(wprobe_fam.attrbuf[WPROBE_ATTR_INTERFACE]);
708 if (!dev)
709 goto done;
710
711 if (cmd == WPROBE_CMD_GET_INFO) {
712 if (wprobe_fam.attrbuf[WPROBE_ATTR_MAC]) {
713 l = wprobe_find_link(dev, nla_data(wprobe_fam.attrbuf[WPROBE_ATTR_MAC]));
714 if (!l)
715 goto done;
716
717 vflags = l->flags;
718 }
719
720 if (l) {
721 item = dev->link_items;
722 n = dev->n_link_items;
723 val = l->val;
724 } else {
725 item = dev->global_items;
726 n = dev->n_global_items;
727 val = dev->val;
728 }
729
730 /* sync data and move to temp storage for the query */
731 spin_lock_irqsave(&dev->lock, flags);
732 err = wprobe_sync_data(dev, l, true);
733 if (!err)
734 memcpy(dev->query_val, val, n * sizeof(struct wprobe_value));
735 spin_unlock_irqrestore(&dev->lock, flags);
736
737 if (err)
738 goto done;
739 }
740
741 if (wprobe_fam.attrbuf[WPROBE_ATTR_FLAGS])
742 vflags |= nla_get_u32(wprobe_fam.attrbuf[WPROBE_ATTR_FLAGS]);
743
744 if (wprobe_fam.attrbuf[WPROBE_ATTR_MAC])
745 vflags |= WPROBE_F_LINK;
746
747 cb->args[0] = (long) dev;
748 cb->args[1] = (long) l;
749 cb->args[2] = vflags;
750 cb->args[3] = 0;
751 } else {
752 /* when pulling pointers from the callback, validate them
753 * against the list using rcu to make sure that we won't
754 * dereference pointers to free'd memory after the last
755 * grace period */
756 err = -ENOENT;
757 if (!wprobe_check_ptr(&wprobe_if, &dev->list))
758 goto done;
759
760 if (l && !wprobe_check_ptr(&dev->links, &l->list))
761 goto done;
762 }
763
764 if (vflags & WPROBE_F_LINK) {
765 item = dev->link_items;
766 n = dev->n_link_items;
767 } else {
768 item = dev->global_items;
769 n = dev->n_global_items;
770 }
771
772 err = 0;
773 switch(cmd) {
774 case WPROBE_CMD_GET_INFO:
775 while (i < n) {
776 if (!wprobe_send_item_value(skb, cb, dev, l, item, i, vflags))
777 break;
778 i++;
779 }
780 break;
781 case WPROBE_CMD_GET_LIST:
782 while (i < n) {
783 if (!wprobe_send_item_info(skb, cb, dev, item, i))
784 break;
785 i++;
786 }
787 break;
788 default:
789 err = -EINVAL;
790 goto done;
791 }
792 cb->args[3] = i;
793 err = skb->len;
794
795 done:
796 rcu_read_unlock();
797 return err;
798 }
799 #undef WPROBE_F_LINK
800
801 static int
802 wprobe_update_auto_measurement(struct wprobe_iface *dev, u32 interval)
803 {
804 if (interval && (interval < WPROBE_MIN_INTERVAL))
805 return -EINVAL;
806
807 if (!interval && dev->measure_interval)
808 del_timer_sync(&dev->measure_timer);
809
810 dev->measure_interval = interval;
811 if (!interval)
812 return 0;
813
814 /* kick of a new measurement immediately */
815 mod_timer(&dev->measure_timer, jiffies + 1);
816
817 return 0;
818 }
819
820 static int
821 wprobe_measure(struct sk_buff *skb, struct genl_info *info)
822 {
823 struct wprobe_iface *dev;
824 struct wprobe_link *l = NULL;
825 int err = -ENOENT;
826
827 rcu_read_lock();
828 dev = wprobe_get_dev(info->attrs[WPROBE_ATTR_INTERFACE]);
829 if (!dev)
830 goto done;
831
832 if (info->attrs[WPROBE_ATTR_MAC]) {
833 l = wprobe_find_link(dev, nla_data(wprobe_fam.attrbuf[WPROBE_ATTR_MAC]));
834 if (!l)
835 goto done;
836 }
837
838 err = wprobe_sync_data(dev, l, false);
839
840 done:
841 rcu_read_unlock();
842 return err;
843 }
844
845 static int
846 wprobe_check_filter(void *data, int datalen, int gs)
847 {
848 struct wprobe_filter_item_hdr *hdr;
849 void *orig_data = data;
850 void *end = data + datalen;
851 int i, j, k, is, cur_is;
852
853 for (i = j = is = 0; i < gs; i++) {
854 hdr = data;
855 data += sizeof(*hdr);
856
857 if (data > end)
858 goto overrun;
859
860 hdr->name[31] = 0;
861 cur_is = be32_to_cpu(hdr->n_items);
862 hdr->n_items = cur_is;
863 is += cur_is;
864 for (j = 0; j < cur_is; j++) {
865 struct sock_filter *sf;
866 int n_items;
867
868 hdr = data;
869 data += sizeof(*hdr);
870 if (data > end)
871 goto overrun;
872
873 hdr->name[31] = 0;
874 n_items = be32_to_cpu(hdr->n_items);
875 hdr->n_items = n_items;
876
877 if (n_items > 1024)
878 goto overrun;
879
880 sf = data;
881 if (n_items > 0) {
882 for (k = 0; k < n_items; k++) {
883 sf->code = be16_to_cpu(sf->code);
884 sf->k = be32_to_cpu(sf->k);
885 sf++;
886 }
887 if (sk_chk_filter(data, n_items) != 0) {
888 printk("%s: filter check failed at group %d, item %d\n", __func__, i, j);
889 return 0;
890 }
891 }
892 data += n_items * sizeof(struct sock_filter);
893 }
894 }
895 return is;
896
897 overrun:
898 printk(KERN_ERR "%s: overrun during filter check at group %d, item %d, offset=%d, len=%d\n", __func__, i, j, (data - orig_data), datalen);
899 return 0;
900 }
901
902 static void
903 wprobe_free_filter(struct wprobe_filter *f)
904 {
905 if (f->skb)
906 kfree_skb(f->skb);
907 if (f->data)
908 kfree(f->data);
909 if (f->items)
910 kfree(f->items);
911 if (f->counters)
912 kfree(f->counters);
913 kfree(f);
914 }
915
916
917 static int
918 wprobe_set_filter(struct wprobe_iface *dev, void *data, int len)
919 {
920 struct wprobe_filter_hdr *fhdr;
921 struct wprobe_rtap_hdr *rtap;
922 struct wprobe_filter *f;
923 int i, j, cur_is, is, gs;
924
925 if (len < sizeof(*fhdr))
926 return -EINVAL;
927
928 fhdr = data;
929 data += sizeof(*fhdr);
930 len -= sizeof(*fhdr);
931
932 if (memcmp(fhdr->magic, "WPFF", 4) != 0) {
933 printk(KERN_ERR "%s: filter rejected (invalid magic)\n", __func__);
934 return -EINVAL;
935 }
936
937 gs = be16_to_cpu(fhdr->n_groups);
938 is = wprobe_check_filter(data, len, gs);
939 if (is == 0)
940 return -EINVAL;
941
942 f = kzalloc(sizeof(struct wprobe_filter) +
943 gs * sizeof(struct wprobe_filter_group), GFP_ATOMIC);
944 if (!f)
945 return -ENOMEM;
946
947 f->skb = alloc_skb(WPROBE_MAX_FRAME_SIZE, GFP_ATOMIC);
948 if (!f->skb)
949 goto error;
950
951 f->data = kmalloc(len, GFP_ATOMIC);
952 if (!f->data)
953 goto error;
954
955 f->items = kzalloc(sizeof(struct wprobe_filter_item *) * is, GFP_ATOMIC);
956 if (!f->items)
957 goto error;
958
959 f->counters = kzalloc(sizeof(struct wprobe_filter_counter) * is, GFP_ATOMIC);
960 if (!f->counters)
961 goto error;
962
963 spin_lock_init(&f->lock);
964 memcpy(f->data, data, len);
965 f->n_groups = gs;
966
967 if (f->hdrlen < sizeof(struct wprobe_wlan_hdr))
968 f->hdrlen = sizeof(struct wprobe_wlan_hdr);
969
970 rtap = (struct wprobe_rtap_hdr *)skb_put(f->skb, sizeof(*rtap));
971 memset(rtap, 0, sizeof(*rtap));
972 rtap->len = cpu_to_le16(sizeof(struct wprobe_rtap_hdr) + f->hdrlen);
973 data = f->data;
974
975 cur_is = 0;
976 for (i = 0; i < gs; i++) {
977 struct wprobe_filter_item_hdr *hdr = data;
978 struct wprobe_filter_group *g = &f->groups[i];
979
980 data += sizeof(*hdr);
981 g->name = hdr->name;
982 g->items = &f->items[cur_is];
983 g->counters = &f->counters[cur_is];
984 g->n_items = hdr->n_items;
985
986 for (j = 0; j < g->n_items; j++) {
987 hdr = data;
988 f->items[cur_is++] = data;
989 data += sizeof(*hdr) + hdr->n_items * sizeof(struct sock_filter);
990 }
991 }
992 rcu_assign_pointer(dev->active_filter, f);
993 return 0;
994
995 error:
996 wprobe_free_filter(f);
997 return -ENOMEM;
998 }
999
1000 static int
1001 wprobe_set_config(struct sk_buff *skb, struct genl_info *info)
1002 {
1003 struct wprobe_iface *dev;
1004 unsigned long flags;
1005 int err = -ENOENT;
1006 u32 scale_min, scale_max;
1007 u32 scale_m, scale_d;
1008 struct nlattr *attr;
1009 struct wprobe_filter *filter_free = NULL;
1010
1011 rcu_read_lock();
1012 dev = wprobe_get_dev(info->attrs[WPROBE_ATTR_INTERFACE]);
1013 if (!dev)
1014 goto done_unlocked;
1015
1016 err = -EINVAL;
1017 spin_lock_irqsave(&dev->lock, flags);
1018 if (info->attrs[WPROBE_ATTR_MAC]) {
1019 /* not supported yet */
1020 goto done;
1021 }
1022
1023 if (info->attrs[WPROBE_ATTR_FLAGS]) {
1024 u32 flags = nla_get_u32(info->attrs[WPROBE_ATTR_FLAGS]);
1025
1026 if (flags & BIT(WPROBE_F_RESET)) {
1027 struct wprobe_link *l;
1028
1029 memset(dev->val, 0, sizeof(struct wprobe_value) * dev->n_global_items);
1030 list_for_each_entry_rcu(l, &dev->links, list) {
1031 memset(l->val, 0, sizeof(struct wprobe_value) * dev->n_link_items);
1032 }
1033 }
1034 }
1035
1036 if (info->attrs[WPROBE_ATTR_SAMPLES_MIN] ||
1037 info->attrs[WPROBE_ATTR_SAMPLES_MAX]) {
1038 if ((attr = info->attrs[WPROBE_ATTR_SAMPLES_MIN]))
1039 scale_min = nla_get_u32(attr);
1040 else
1041 scale_min = dev->scale_min;
1042
1043 if ((attr = info->attrs[WPROBE_ATTR_SAMPLES_MAX]))
1044 scale_max = nla_get_u32(attr);
1045 else
1046 scale_max = dev->scale_max;
1047
1048 if ((!scale_min && !scale_max) ||
1049 (scale_min && scale_max && (scale_min < scale_max))) {
1050 dev->scale_min = scale_min;
1051 dev->scale_max = scale_max;
1052 } else {
1053 goto done;
1054 }
1055 }
1056
1057 if (info->attrs[WPROBE_ATTR_SAMPLES_SCALE_M] &&
1058 info->attrs[WPROBE_ATTR_SAMPLES_SCALE_D]) {
1059
1060 scale_m = nla_get_u32(info->attrs[WPROBE_ATTR_SAMPLES_SCALE_M]);
1061 scale_d = nla_get_u32(info->attrs[WPROBE_ATTR_SAMPLES_SCALE_D]);
1062
1063 if (!scale_d || (scale_m > scale_d))
1064 goto done;
1065
1066 dev->scale_m = scale_m;
1067 dev->scale_d = scale_d;
1068 }
1069
1070 if ((attr = info->attrs[WPROBE_ATTR_FILTER])) {
1071 filter_free = rcu_dereference(dev->active_filter);
1072 rcu_assign_pointer(dev->active_filter, NULL);
1073 if (nla_len(attr) > 0)
1074 wprobe_set_filter(dev, nla_data(attr), nla_len(attr));
1075 }
1076
1077 err = 0;
1078 if (info->attrs[WPROBE_ATTR_INTERVAL]) {
1079 /* change of measurement interval requested */
1080 err = wprobe_update_auto_measurement(dev,
1081 (u32) nla_get_u64(info->attrs[WPROBE_ATTR_INTERVAL]));
1082 }
1083
1084 done:
1085 spin_unlock_irqrestore(&dev->lock, flags);
1086 done_unlocked:
1087 rcu_read_unlock();
1088 if (filter_free) {
1089 synchronize_rcu();
1090 wprobe_free_filter(filter_free);
1091 }
1092 return err;
1093 }
1094
1095 static struct genl_ops wprobe_ops[] = {
1096 {
1097 .cmd = WPROBE_CMD_GET_INFO,
1098 .dumpit = wprobe_dump_info,
1099 .policy = wprobe_policy,
1100 },
1101 {
1102 .cmd = WPROBE_CMD_GET_LIST,
1103 .dumpit = wprobe_dump_info,
1104 .policy = wprobe_policy,
1105 },
1106 {
1107 .cmd = WPROBE_CMD_MEASURE,
1108 .doit = wprobe_measure,
1109 .policy = wprobe_policy,
1110 },
1111 {
1112 .cmd = WPROBE_CMD_GET_LINKS,
1113 .dumpit = wprobe_dump_links,
1114 .policy = wprobe_policy,
1115 },
1116 {
1117 .cmd = WPROBE_CMD_CONFIG,
1118 .doit = wprobe_set_config,
1119 .policy = wprobe_policy,
1120 },
1121 {
1122 .cmd = WPROBE_CMD_GET_FILTER,
1123 .dumpit = wprobe_dump_filters,
1124 .policy = wprobe_policy,
1125 },
1126 };
1127
1128 static void __exit
1129 wprobe_exit(void)
1130 {
1131 BUG_ON(!list_empty(&wprobe_if));
1132 genl_unregister_family(&wprobe_fam);
1133 }
1134
1135
1136 static int __init
1137 wprobe_init(void)
1138 {
1139 int i, err;
1140
1141 spin_lock_init(&wprobe_lock);
1142 INIT_LIST_HEAD(&wprobe_if);
1143
1144 err = genl_register_family(&wprobe_fam);
1145 if (err)
1146 return err;
1147
1148 for (i = 0; i < ARRAY_SIZE(wprobe_ops); i++) {
1149 err = genl_register_ops(&wprobe_fam, &wprobe_ops[i]);
1150 if (err)
1151 goto error;
1152 }
1153
1154 return 0;
1155
1156 error:
1157 genl_unregister_family(&wprobe_fam);
1158 return err;
1159 }
1160
1161 module_init(wprobe_init);
1162 module_exit(wprobe_exit);
1163 MODULE_LICENSE("GPL");
1164
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