]>
Commit | Line | Data |
---|---|---|
7af4cc3f HW |
1 | /* |
2 | * This is a module which is used for queueing packets and communicating with | |
3 | * userspace via nfetlink. | |
4 | * | |
5 | * (C) 2005 by Harald Welte <laforge@netfilter.org> | |
6 | * | |
7 | * Based on the old ipv4-only ip_queue.c: | |
8 | * (C) 2000-2002 James Morris <jmorris@intercode.com.au> | |
9 | * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | */ | |
16 | #include <linux/module.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/spinlock.h> | |
20 | #include <linux/notifier.h> | |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/netfilter.h> | |
23 | #include <linux/netfilter_ipv4.h> | |
24 | #include <linux/netfilter_ipv6.h> | |
25 | #include <linux/netfilter/nfnetlink.h> | |
26 | #include <linux/netfilter/nfnetlink_queue.h> | |
27 | #include <linux/list.h> | |
28 | #include <net/sock.h> | |
29 | ||
30 | #include <asm/atomic.h> | |
31 | ||
32 | #define NFQNL_QMAX_DEFAULT 1024 | |
33 | ||
34 | #if 0 | |
35 | #define QDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ | |
36 | __FILE__, __LINE__, __FUNCTION__, \ | |
37 | ## args) | |
38 | #else | |
39 | #define QDEBUG(x, ...) | |
40 | #endif | |
41 | ||
42 | struct nfqnl_queue_entry { | |
43 | struct list_head list; | |
44 | struct nf_info *info; | |
45 | struct sk_buff *skb; | |
46 | unsigned int id; | |
47 | }; | |
48 | ||
49 | struct nfqnl_instance { | |
50 | struct hlist_node hlist; /* global list of queues */ | |
51 | ||
52 | int peer_pid; | |
53 | unsigned int queue_maxlen; | |
54 | unsigned int copy_range; | |
55 | unsigned int queue_total; | |
56 | unsigned int queue_dropped; | |
57 | unsigned int queue_user_dropped; | |
58 | ||
59 | atomic_t id_sequence; /* 'sequence' of pkt ids */ | |
60 | ||
61 | u_int16_t queue_num; /* number of this queue */ | |
62 | u_int8_t copy_mode; | |
63 | ||
64 | spinlock_t lock; | |
65 | ||
66 | struct list_head queue_list; /* packets in queue */ | |
67 | }; | |
68 | ||
69 | typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long); | |
70 | ||
71 | static DEFINE_RWLOCK(instances_lock); | |
72 | ||
73 | u_int64_t htonll(u_int64_t in) | |
74 | { | |
75 | u_int64_t out; | |
76 | int i; | |
77 | ||
78 | for (i = 0; i < sizeof(u_int64_t); i++) | |
79 | ((u_int8_t *)&out)[sizeof(u_int64_t)-1] = ((u_int8_t *)&in)[i]; | |
80 | ||
81 | return out; | |
82 | } | |
83 | ||
84 | #define INSTANCE_BUCKETS 16 | |
85 | static struct hlist_head instance_table[INSTANCE_BUCKETS]; | |
86 | ||
87 | static inline u_int8_t instance_hashfn(u_int16_t queue_num) | |
88 | { | |
89 | return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS; | |
90 | } | |
91 | ||
92 | static struct nfqnl_instance * | |
93 | __instance_lookup(u_int16_t queue_num) | |
94 | { | |
95 | struct hlist_head *head; | |
96 | struct hlist_node *pos; | |
97 | struct nfqnl_instance *inst; | |
98 | ||
99 | head = &instance_table[instance_hashfn(queue_num)]; | |
100 | hlist_for_each_entry(inst, pos, head, hlist) { | |
101 | if (inst->queue_num == queue_num) | |
102 | return inst; | |
103 | } | |
104 | return NULL; | |
105 | } | |
106 | ||
107 | static struct nfqnl_instance * | |
108 | instance_lookup(u_int16_t queue_num) | |
109 | { | |
110 | struct nfqnl_instance *inst; | |
111 | ||
112 | read_lock_bh(&instances_lock); | |
113 | inst = __instance_lookup(queue_num); | |
114 | read_unlock_bh(&instances_lock); | |
115 | ||
116 | return inst; | |
117 | } | |
118 | ||
119 | static struct nfqnl_instance * | |
120 | instance_create(u_int16_t queue_num, int pid) | |
121 | { | |
122 | struct nfqnl_instance *inst; | |
123 | ||
124 | QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid); | |
125 | ||
126 | write_lock_bh(&instances_lock); | |
127 | if (__instance_lookup(queue_num)) { | |
128 | inst = NULL; | |
129 | QDEBUG("aborting, instance already exists\n"); | |
130 | goto out_unlock; | |
131 | } | |
132 | ||
133 | inst = kmalloc(sizeof(*inst), GFP_ATOMIC); | |
134 | if (!inst) | |
135 | goto out_unlock; | |
136 | ||
137 | memset(inst, 0, sizeof(*inst)); | |
138 | inst->queue_num = queue_num; | |
139 | inst->peer_pid = pid; | |
140 | inst->queue_maxlen = NFQNL_QMAX_DEFAULT; | |
141 | inst->copy_range = 0xfffff; | |
142 | inst->copy_mode = NFQNL_COPY_NONE; | |
143 | atomic_set(&inst->id_sequence, 0); | |
144 | inst->lock = SPIN_LOCK_UNLOCKED; | |
145 | INIT_LIST_HEAD(&inst->queue_list); | |
146 | ||
147 | if (!try_module_get(THIS_MODULE)) | |
148 | goto out_free; | |
149 | ||
150 | hlist_add_head(&inst->hlist, | |
151 | &instance_table[instance_hashfn(queue_num)]); | |
152 | ||
153 | write_unlock_bh(&instances_lock); | |
154 | ||
155 | QDEBUG("successfully created new instance\n"); | |
156 | ||
157 | return inst; | |
158 | ||
159 | out_free: | |
160 | kfree(inst); | |
161 | out_unlock: | |
162 | write_unlock_bh(&instances_lock); | |
163 | return NULL; | |
164 | } | |
165 | ||
166 | static void nfqnl_flush(struct nfqnl_instance *queue, int verdict); | |
167 | ||
168 | static void | |
169 | _instance_destroy2(struct nfqnl_instance *inst, int lock) | |
170 | { | |
171 | /* first pull it out of the global list */ | |
172 | if (lock) | |
173 | write_lock_bh(&instances_lock); | |
174 | ||
175 | QDEBUG("removing instance %p (queuenum=%u) from hash\n", | |
176 | inst, inst->queue_num); | |
177 | hlist_del(&inst->hlist); | |
178 | ||
179 | if (lock) | |
180 | write_unlock_bh(&instances_lock); | |
181 | ||
182 | /* then flush all pending skbs from the queue */ | |
183 | nfqnl_flush(inst, NF_DROP); | |
184 | ||
185 | /* and finally free the data structure */ | |
186 | kfree(inst); | |
187 | ||
188 | module_put(THIS_MODULE); | |
189 | } | |
190 | ||
191 | static inline void | |
192 | __instance_destroy(struct nfqnl_instance *inst) | |
193 | { | |
194 | _instance_destroy2(inst, 0); | |
195 | } | |
196 | ||
197 | static inline void | |
198 | instance_destroy(struct nfqnl_instance *inst) | |
199 | { | |
200 | _instance_destroy2(inst, 1); | |
201 | } | |
202 | ||
203 | ||
204 | ||
205 | static void | |
206 | issue_verdict(struct nfqnl_queue_entry *entry, int verdict) | |
207 | { | |
208 | QDEBUG("entering for entry %p, verdict %u\n", entry, verdict); | |
209 | ||
210 | /* TCP input path (and probably other bits) assume to be called | |
211 | * from softirq context, not from syscall, like issue_verdict is | |
212 | * called. TCP input path deadlocks with locks taken from timer | |
213 | * softirq, e.g. We therefore emulate this by local_bh_disable() */ | |
214 | ||
215 | local_bh_disable(); | |
216 | nf_reinject(entry->skb, entry->info, verdict); | |
217 | local_bh_enable(); | |
218 | ||
219 | kfree(entry); | |
220 | } | |
221 | ||
222 | static inline void | |
223 | __enqueue_entry(struct nfqnl_instance *queue, | |
224 | struct nfqnl_queue_entry *entry) | |
225 | { | |
226 | list_add(&entry->list, &queue->queue_list); | |
227 | queue->queue_total++; | |
228 | } | |
229 | ||
230 | /* | |
231 | * Find and return a queued entry matched by cmpfn, or return the last | |
232 | * entry if cmpfn is NULL. | |
233 | */ | |
234 | static inline struct nfqnl_queue_entry * | |
235 | __find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, | |
236 | unsigned long data) | |
237 | { | |
238 | struct list_head *p; | |
239 | ||
240 | list_for_each_prev(p, &queue->queue_list) { | |
241 | struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p; | |
242 | ||
243 | if (!cmpfn || cmpfn(entry, data)) | |
244 | return entry; | |
245 | } | |
246 | return NULL; | |
247 | } | |
248 | ||
249 | static inline void | |
250 | __dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry) | |
251 | { | |
252 | list_del(&entry->list); | |
253 | q->queue_total--; | |
254 | } | |
255 | ||
256 | static inline struct nfqnl_queue_entry * | |
257 | __find_dequeue_entry(struct nfqnl_instance *queue, | |
258 | nfqnl_cmpfn cmpfn, unsigned long data) | |
259 | { | |
260 | struct nfqnl_queue_entry *entry; | |
261 | ||
262 | entry = __find_entry(queue, cmpfn, data); | |
263 | if (entry == NULL) | |
264 | return NULL; | |
265 | ||
266 | __dequeue_entry(queue, entry); | |
267 | return entry; | |
268 | } | |
269 | ||
270 | ||
271 | static inline void | |
272 | __nfqnl_flush(struct nfqnl_instance *queue, int verdict) | |
273 | { | |
274 | struct nfqnl_queue_entry *entry; | |
275 | ||
276 | while ((entry = __find_dequeue_entry(queue, NULL, 0))) | |
277 | issue_verdict(entry, verdict); | |
278 | } | |
279 | ||
280 | static inline int | |
281 | __nfqnl_set_mode(struct nfqnl_instance *queue, | |
282 | unsigned char mode, unsigned int range) | |
283 | { | |
284 | int status = 0; | |
285 | ||
286 | switch (mode) { | |
287 | case NFQNL_COPY_NONE: | |
288 | case NFQNL_COPY_META: | |
289 | queue->copy_mode = mode; | |
290 | queue->copy_range = 0; | |
291 | break; | |
292 | ||
293 | case NFQNL_COPY_PACKET: | |
294 | queue->copy_mode = mode; | |
295 | /* we're using struct nfattr which has 16bit nfa_len */ | |
296 | if (range > 0xffff) | |
297 | queue->copy_range = 0xffff; | |
298 | else | |
299 | queue->copy_range = range; | |
300 | break; | |
301 | ||
302 | default: | |
303 | status = -EINVAL; | |
304 | ||
305 | } | |
306 | return status; | |
307 | } | |
308 | ||
309 | static struct nfqnl_queue_entry * | |
310 | find_dequeue_entry(struct nfqnl_instance *queue, | |
311 | nfqnl_cmpfn cmpfn, unsigned long data) | |
312 | { | |
313 | struct nfqnl_queue_entry *entry; | |
314 | ||
315 | spin_lock_bh(&queue->lock); | |
316 | entry = __find_dequeue_entry(queue, cmpfn, data); | |
317 | spin_unlock_bh(&queue->lock); | |
318 | ||
319 | return entry; | |
320 | } | |
321 | ||
322 | static void | |
323 | nfqnl_flush(struct nfqnl_instance *queue, int verdict) | |
324 | { | |
325 | spin_lock_bh(&queue->lock); | |
326 | __nfqnl_flush(queue, verdict); | |
327 | spin_unlock_bh(&queue->lock); | |
328 | } | |
329 | ||
330 | static struct sk_buff * | |
331 | nfqnl_build_packet_message(struct nfqnl_instance *queue, | |
332 | struct nfqnl_queue_entry *entry, int *errp) | |
333 | { | |
334 | unsigned char *old_tail; | |
335 | size_t size; | |
336 | size_t data_len = 0; | |
337 | struct sk_buff *skb; | |
338 | struct nfqnl_msg_packet_hdr pmsg; | |
339 | struct nlmsghdr *nlh; | |
340 | struct nfgenmsg *nfmsg; | |
341 | unsigned int tmp_uint; | |
342 | ||
343 | QDEBUG("entered\n"); | |
344 | ||
345 | /* all macros expand to constant values at compile time */ | |
346 | size = NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr)) | |
347 | + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
348 | + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
349 | + NLMSG_SPACE(sizeof(u_int32_t)) /* mark */ | |
350 | + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw)) | |
351 | + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp)); | |
352 | ||
353 | spin_lock_bh(&queue->lock); | |
354 | ||
355 | switch (queue->copy_mode) { | |
356 | case NFQNL_COPY_META: | |
357 | case NFQNL_COPY_NONE: | |
358 | data_len = 0; | |
359 | break; | |
360 | ||
361 | case NFQNL_COPY_PACKET: | |
362 | if (queue->copy_range == 0 | |
363 | || queue->copy_range > entry->skb->len) | |
364 | data_len = entry->skb->len; | |
365 | else | |
366 | data_len = queue->copy_range; | |
367 | ||
368 | size += NLMSG_SPACE(data_len); | |
369 | break; | |
370 | ||
371 | default: | |
372 | *errp = -EINVAL; | |
373 | spin_unlock_bh(&queue->lock); | |
374 | return NULL; | |
375 | } | |
376 | ||
377 | spin_unlock_bh(&queue->lock); | |
378 | ||
379 | skb = alloc_skb(size, GFP_ATOMIC); | |
380 | if (!skb) | |
381 | goto nlmsg_failure; | |
382 | ||
383 | old_tail= skb->tail; | |
384 | nlh = NLMSG_PUT(skb, 0, 0, | |
385 | NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, | |
386 | sizeof(struct nfgenmsg)); | |
387 | nfmsg = NLMSG_DATA(nlh); | |
388 | nfmsg->nfgen_family = entry->info->pf; | |
389 | nfmsg->version = NFNETLINK_V0; | |
390 | nfmsg->res_id = htons(queue->queue_num); | |
391 | ||
392 | pmsg.packet_id = htonl(entry->id); | |
393 | pmsg.hw_protocol = htons(entry->skb->protocol); | |
394 | pmsg.hook = entry->info->hook; | |
395 | ||
396 | NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg); | |
397 | ||
398 | if (entry->info->indev) { | |
399 | tmp_uint = htonl(entry->info->indev->ifindex); | |
400 | NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint); | |
401 | } | |
402 | ||
403 | if (entry->info->outdev) { | |
404 | tmp_uint = htonl(entry->info->outdev->ifindex); | |
405 | NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint); | |
406 | } | |
407 | ||
408 | if (entry->skb->nfmark) { | |
409 | tmp_uint = htonl(entry->skb->nfmark); | |
410 | NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint); | |
411 | } | |
412 | ||
413 | if (entry->info->indev && entry->skb->dev | |
414 | && entry->skb->dev->hard_header_parse) { | |
415 | struct nfqnl_msg_packet_hw phw; | |
416 | ||
417 | phw.hw_addrlen = | |
418 | entry->skb->dev->hard_header_parse(entry->skb, | |
419 | phw.hw_addr); | |
420 | phw.hw_addrlen = htons(phw.hw_addrlen); | |
421 | NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw); | |
422 | } | |
423 | ||
424 | if (entry->skb->stamp.tv_sec) { | |
425 | struct nfqnl_msg_packet_timestamp ts; | |
426 | ||
427 | ts.sec = htonll(entry->skb->stamp.tv_sec); | |
428 | ts.usec = htonll(entry->skb->stamp.tv_usec); | |
429 | ||
430 | NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts); | |
431 | } | |
432 | ||
433 | if (data_len) { | |
434 | struct nfattr *nfa; | |
435 | int size = NFA_LENGTH(data_len); | |
436 | ||
437 | if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) { | |
438 | printk(KERN_WARNING "nf_queue: no tailroom!\n"); | |
439 | goto nlmsg_failure; | |
440 | } | |
441 | ||
442 | nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size)); | |
443 | nfa->nfa_type = NFQA_PAYLOAD; | |
444 | nfa->nfa_len = size; | |
445 | ||
446 | if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len)) | |
447 | BUG(); | |
448 | } | |
449 | ||
450 | nlh->nlmsg_len = skb->tail - old_tail; | |
451 | return skb; | |
452 | ||
453 | nlmsg_failure: | |
454 | nfattr_failure: | |
455 | if (skb) | |
456 | kfree_skb(skb); | |
457 | *errp = -EINVAL; | |
458 | if (net_ratelimit()) | |
459 | printk(KERN_ERR "nf_queue: error creating packet message\n"); | |
460 | return NULL; | |
461 | } | |
462 | ||
463 | static int | |
464 | nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info, | |
465 | unsigned int queuenum, void *data) | |
466 | { | |
467 | int status = -EINVAL; | |
468 | struct sk_buff *nskb; | |
469 | struct nfqnl_instance *queue; | |
470 | struct nfqnl_queue_entry *entry; | |
471 | ||
472 | QDEBUG("entered\n"); | |
473 | ||
474 | queue = instance_lookup(queuenum); | |
475 | if (!queue) { | |
476 | QDEBUG("no queue instance matching\n"); | |
477 | return -EINVAL; | |
478 | } | |
479 | ||
480 | if (queue->copy_mode == NFQNL_COPY_NONE) { | |
481 | QDEBUG("mode COPY_NONE, aborting\n"); | |
482 | return -EAGAIN; | |
483 | } | |
484 | ||
485 | entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
486 | if (entry == NULL) { | |
487 | if (net_ratelimit()) | |
488 | printk(KERN_ERR | |
489 | "nf_queue: OOM in nfqnl_enqueue_packet()\n"); | |
490 | return -ENOMEM; | |
491 | } | |
492 | ||
493 | entry->info = info; | |
494 | entry->skb = skb; | |
495 | entry->id = atomic_inc_return(&queue->id_sequence); | |
496 | ||
497 | nskb = nfqnl_build_packet_message(queue, entry, &status); | |
498 | if (nskb == NULL) | |
499 | goto err_out_free; | |
500 | ||
501 | spin_lock_bh(&queue->lock); | |
502 | ||
503 | if (!queue->peer_pid) | |
504 | goto err_out_free_nskb; | |
505 | ||
506 | if (queue->queue_total >= queue->queue_maxlen) { | |
507 | queue->queue_dropped++; | |
508 | status = -ENOSPC; | |
509 | if (net_ratelimit()) | |
510 | printk(KERN_WARNING "ip_queue: full at %d entries, " | |
511 | "dropping packets(s). Dropped: %d\n", | |
512 | queue->queue_total, queue->queue_dropped); | |
513 | goto err_out_free_nskb; | |
514 | } | |
515 | ||
516 | /* nfnetlink_unicast will either free the nskb or add it to a socket */ | |
517 | status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT); | |
518 | if (status < 0) { | |
519 | queue->queue_user_dropped++; | |
520 | goto err_out_unlock; | |
521 | } | |
522 | ||
523 | __enqueue_entry(queue, entry); | |
524 | ||
525 | spin_unlock_bh(&queue->lock); | |
526 | return status; | |
527 | ||
528 | err_out_free_nskb: | |
529 | kfree_skb(nskb); | |
530 | ||
531 | err_out_unlock: | |
532 | spin_unlock_bh(&queue->lock); | |
533 | ||
534 | err_out_free: | |
535 | kfree(entry); | |
536 | return status; | |
537 | } | |
538 | ||
539 | static int | |
540 | nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e) | |
541 | { | |
542 | int diff; | |
543 | ||
544 | diff = data_len - e->skb->len; | |
545 | if (diff < 0) | |
546 | skb_trim(e->skb, data_len); | |
547 | else if (diff > 0) { | |
548 | if (data_len > 0xFFFF) | |
549 | return -EINVAL; | |
550 | if (diff > skb_tailroom(e->skb)) { | |
551 | struct sk_buff *newskb; | |
552 | ||
553 | newskb = skb_copy_expand(e->skb, | |
554 | skb_headroom(e->skb), | |
555 | diff, | |
556 | GFP_ATOMIC); | |
557 | if (newskb == NULL) { | |
558 | printk(KERN_WARNING "ip_queue: OOM " | |
559 | "in mangle, dropping packet\n"); | |
560 | return -ENOMEM; | |
561 | } | |
562 | if (e->skb->sk) | |
563 | skb_set_owner_w(newskb, e->skb->sk); | |
564 | kfree_skb(e->skb); | |
565 | e->skb = newskb; | |
566 | } | |
567 | skb_put(e->skb, diff); | |
568 | } | |
569 | if (!skb_make_writable(&e->skb, data_len)) | |
570 | return -ENOMEM; | |
571 | memcpy(e->skb->data, data, data_len); | |
572 | ||
573 | return 0; | |
574 | } | |
575 | ||
576 | static inline int | |
577 | id_cmp(struct nfqnl_queue_entry *e, unsigned long id) | |
578 | { | |
579 | return (id == e->id); | |
580 | } | |
581 | ||
582 | static int | |
583 | nfqnl_set_mode(struct nfqnl_instance *queue, | |
584 | unsigned char mode, unsigned int range) | |
585 | { | |
586 | int status; | |
587 | ||
588 | spin_lock_bh(&queue->lock); | |
589 | status = __nfqnl_set_mode(queue, mode, range); | |
590 | spin_unlock_bh(&queue->lock); | |
591 | ||
592 | return status; | |
593 | } | |
594 | ||
595 | static int | |
596 | dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex) | |
597 | { | |
598 | if (entry->info->indev) | |
599 | if (entry->info->indev->ifindex == ifindex) | |
600 | return 1; | |
601 | ||
602 | if (entry->info->outdev) | |
603 | if (entry->info->outdev->ifindex == ifindex) | |
604 | return 1; | |
605 | ||
606 | return 0; | |
607 | } | |
608 | ||
609 | /* drop all packets with either indev or outdev == ifindex from all queue | |
610 | * instances */ | |
611 | static void | |
612 | nfqnl_dev_drop(int ifindex) | |
613 | { | |
614 | int i; | |
615 | ||
616 | QDEBUG("entering for ifindex %u\n", ifindex); | |
617 | ||
618 | /* this only looks like we have to hold the readlock for a way too long | |
619 | * time, issue_verdict(), nf_reinject(), ... - but we always only | |
620 | * issue NF_DROP, which is processed directly in nf_reinject() */ | |
621 | read_lock_bh(&instances_lock); | |
622 | ||
623 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
624 | struct hlist_node *tmp; | |
625 | struct nfqnl_instance *inst; | |
626 | struct hlist_head *head = &instance_table[i]; | |
627 | ||
628 | hlist_for_each_entry(inst, tmp, head, hlist) { | |
629 | struct nfqnl_queue_entry *entry; | |
630 | while ((entry = find_dequeue_entry(inst, dev_cmp, | |
631 | ifindex)) != NULL) | |
632 | issue_verdict(entry, NF_DROP); | |
633 | } | |
634 | } | |
635 | ||
636 | read_unlock_bh(&instances_lock); | |
637 | } | |
638 | ||
639 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
640 | ||
641 | static int | |
642 | nfqnl_rcv_dev_event(struct notifier_block *this, | |
643 | unsigned long event, void *ptr) | |
644 | { | |
645 | struct net_device *dev = ptr; | |
646 | ||
647 | /* Drop any packets associated with the downed device */ | |
648 | if (event == NETDEV_DOWN) | |
649 | nfqnl_dev_drop(dev->ifindex); | |
650 | return NOTIFY_DONE; | |
651 | } | |
652 | ||
653 | static struct notifier_block nfqnl_dev_notifier = { | |
654 | .notifier_call = nfqnl_rcv_dev_event, | |
655 | }; | |
656 | ||
657 | static int | |
658 | nfqnl_rcv_nl_event(struct notifier_block *this, | |
659 | unsigned long event, void *ptr) | |
660 | { | |
661 | struct netlink_notify *n = ptr; | |
662 | ||
663 | if (event == NETLINK_URELEASE && | |
664 | n->protocol == NETLINK_NETFILTER && n->pid) { | |
665 | int i; | |
666 | ||
667 | /* destroy all instances for this pid */ | |
668 | write_lock_bh(&instances_lock); | |
669 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
670 | struct hlist_node *tmp, *t2; | |
671 | struct nfqnl_instance *inst; | |
672 | struct hlist_head *head = &instance_table[i]; | |
673 | ||
674 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { | |
675 | if (n->pid == inst->peer_pid) | |
676 | __instance_destroy(inst); | |
677 | } | |
678 | } | |
679 | write_unlock_bh(&instances_lock); | |
680 | } | |
681 | return NOTIFY_DONE; | |
682 | } | |
683 | ||
684 | static struct notifier_block nfqnl_rtnl_notifier = { | |
685 | .notifier_call = nfqnl_rcv_nl_event, | |
686 | }; | |
687 | ||
688 | static int | |
689 | nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, | |
690 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
691 | { | |
692 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
693 | u_int16_t queue_num = ntohs(nfmsg->res_id); | |
694 | ||
695 | struct nfqnl_msg_verdict_hdr *vhdr; | |
696 | struct nfqnl_instance *queue; | |
697 | unsigned int verdict; | |
698 | struct nfqnl_queue_entry *entry; | |
699 | ||
700 | queue = instance_lookup(queue_num); | |
701 | if (!queue) | |
702 | return -ENODEV; | |
703 | ||
704 | if (queue->peer_pid != NETLINK_CB(skb).pid) | |
705 | return -EPERM; | |
706 | ||
707 | if (!nfqa[NFQA_VERDICT_HDR-1]) | |
708 | return -EINVAL; | |
709 | ||
710 | vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]); | |
711 | verdict = ntohl(vhdr->verdict); | |
712 | ||
713 | if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) | |
714 | return -EINVAL; | |
715 | ||
716 | entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id)); | |
717 | if (entry == NULL) | |
718 | return -ENOENT; | |
719 | ||
720 | if (nfqa[NFQA_PAYLOAD-1]) { | |
721 | if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]), | |
722 | NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0) | |
723 | verdict = NF_DROP; | |
724 | } | |
725 | ||
726 | if (nfqa[NFQA_MARK-1]) | |
727 | skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1])); | |
728 | ||
729 | issue_verdict(entry, verdict); | |
730 | return 0; | |
731 | } | |
732 | ||
733 | static int | |
734 | nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, | |
735 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
736 | { | |
737 | return -ENOTSUPP; | |
738 | } | |
739 | ||
740 | static int | |
741 | nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb, | |
742 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
743 | { | |
744 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
745 | u_int16_t queue_num = ntohs(nfmsg->res_id); | |
746 | struct nfqnl_instance *queue; | |
747 | ||
748 | QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); | |
749 | ||
750 | queue = instance_lookup(queue_num); | |
751 | if (nfqa[NFQA_CFG_CMD-1]) { | |
752 | struct nfqnl_msg_config_cmd *cmd; | |
753 | cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]); | |
754 | QDEBUG("found CFG_CMD\n"); | |
755 | ||
756 | switch (cmd->command) { | |
757 | case NFQNL_CFG_CMD_BIND: | |
758 | if (queue) | |
759 | return -EBUSY; | |
760 | ||
761 | queue = instance_create(queue_num, NETLINK_CB(skb).pid); | |
762 | if (!queue) | |
763 | return -EINVAL; | |
764 | break; | |
765 | case NFQNL_CFG_CMD_UNBIND: | |
766 | if (!queue) | |
767 | return -ENODEV; | |
768 | ||
769 | if (queue->peer_pid != NETLINK_CB(skb).pid) | |
770 | return -EPERM; | |
771 | ||
772 | instance_destroy(queue); | |
773 | break; | |
774 | case NFQNL_CFG_CMD_PF_BIND: | |
775 | QDEBUG("registering queue handler for pf=%u\n", | |
776 | ntohs(cmd->pf)); | |
777 | return nf_register_queue_handler(ntohs(cmd->pf), | |
778 | nfqnl_enqueue_packet, | |
779 | NULL); | |
780 | ||
781 | break; | |
782 | case NFQNL_CFG_CMD_PF_UNBIND: | |
783 | QDEBUG("unregistering queue handler for pf=%u\n", | |
784 | ntohs(cmd->pf)); | |
785 | /* This is a bug and a feature. We can unregister | |
786 | * other handlers(!) */ | |
787 | return nf_unregister_queue_handler(ntohs(cmd->pf)); | |
788 | break; | |
789 | default: | |
790 | return -EINVAL; | |
791 | } | |
792 | } else { | |
793 | if (!queue) { | |
794 | QDEBUG("no config command, and no instance ENOENT\n"); | |
795 | return -ENOENT; | |
796 | } | |
797 | ||
798 | if (queue->peer_pid != NETLINK_CB(skb).pid) { | |
799 | QDEBUG("no config command, and wrong pid\n"); | |
800 | return -EPERM; | |
801 | } | |
802 | } | |
803 | ||
804 | if (nfqa[NFQA_CFG_PARAMS-1]) { | |
805 | struct nfqnl_msg_config_params *params; | |
806 | params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]); | |
807 | ||
808 | nfqnl_set_mode(queue, params->copy_mode, | |
809 | ntohl(params->copy_range)); | |
810 | } | |
811 | ||
812 | return 0; | |
813 | } | |
814 | ||
815 | static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { | |
816 | [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, | |
817 | .cap_required = CAP_NET_ADMIN }, | |
818 | [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, | |
819 | .cap_required = CAP_NET_ADMIN }, | |
820 | [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, | |
821 | .cap_required = CAP_NET_ADMIN }, | |
822 | }; | |
823 | ||
824 | static struct nfnetlink_subsystem nfqnl_subsys = { | |
825 | .name = "nf_queue", | |
826 | .subsys_id = NFNL_SUBSYS_QUEUE, | |
827 | .cb_count = NFQNL_MSG_MAX, | |
828 | .attr_count = NFQA_MAX, | |
829 | .cb = nfqnl_cb, | |
830 | }; | |
831 | ||
832 | static int | |
833 | init_or_cleanup(int init) | |
834 | { | |
835 | int status = -ENOMEM; | |
836 | ||
837 | if (!init) | |
838 | goto cleanup; | |
839 | ||
840 | netlink_register_notifier(&nfqnl_rtnl_notifier); | |
841 | status = nfnetlink_subsys_register(&nfqnl_subsys); | |
842 | if (status < 0) { | |
843 | printk(KERN_ERR "nf_queue: failed to create netlink socket\n"); | |
844 | goto cleanup_netlink_notifier; | |
845 | } | |
846 | ||
847 | register_netdevice_notifier(&nfqnl_dev_notifier); | |
848 | return status; | |
849 | ||
850 | cleanup: | |
851 | nf_unregister_queue_handlers(nfqnl_enqueue_packet); | |
852 | unregister_netdevice_notifier(&nfqnl_dev_notifier); | |
853 | nfnetlink_subsys_unregister(&nfqnl_subsys); | |
854 | ||
855 | cleanup_netlink_notifier: | |
856 | netlink_unregister_notifier(&nfqnl_rtnl_notifier); | |
857 | return status; | |
858 | } | |
859 | ||
860 | static int __init init(void) | |
861 | { | |
862 | ||
863 | return init_or_cleanup(1); | |
864 | } | |
865 | ||
866 | static void __exit fini(void) | |
867 | { | |
868 | init_or_cleanup(0); | |
869 | } | |
870 | ||
871 | MODULE_DESCRIPTION("netfilter packet queue handler"); | |
872 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
873 | MODULE_LICENSE("GPL"); | |
874 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE); | |
875 | ||
876 | module_init(init); | |
877 | module_exit(fini); |