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> | |
838ab636 | 23 | #include <linux/proc_fs.h> |
7af4cc3f HW |
24 | #include <linux/netfilter_ipv4.h> |
25 | #include <linux/netfilter_ipv6.h> | |
26 | #include <linux/netfilter/nfnetlink.h> | |
27 | #include <linux/netfilter/nfnetlink_queue.h> | |
28 | #include <linux/list.h> | |
29 | #include <net/sock.h> | |
30 | ||
31 | #include <asm/atomic.h> | |
32 | ||
33 | #define NFQNL_QMAX_DEFAULT 1024 | |
34 | ||
35 | #if 0 | |
36 | #define QDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ | |
37 | __FILE__, __LINE__, __FUNCTION__, \ | |
38 | ## args) | |
39 | #else | |
40 | #define QDEBUG(x, ...) | |
41 | #endif | |
42 | ||
43 | struct nfqnl_queue_entry { | |
44 | struct list_head list; | |
45 | struct nf_info *info; | |
46 | struct sk_buff *skb; | |
47 | unsigned int id; | |
48 | }; | |
49 | ||
50 | struct nfqnl_instance { | |
51 | struct hlist_node hlist; /* global list of queues */ | |
838ab636 | 52 | atomic_t use; |
7af4cc3f HW |
53 | |
54 | int peer_pid; | |
55 | unsigned int queue_maxlen; | |
56 | unsigned int copy_range; | |
57 | unsigned int queue_total; | |
58 | unsigned int queue_dropped; | |
59 | unsigned int queue_user_dropped; | |
60 | ||
61 | atomic_t id_sequence; /* 'sequence' of pkt ids */ | |
62 | ||
63 | u_int16_t queue_num; /* number of this queue */ | |
64 | u_int8_t copy_mode; | |
65 | ||
66 | spinlock_t lock; | |
67 | ||
68 | struct list_head queue_list; /* packets in queue */ | |
69 | }; | |
70 | ||
71 | typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long); | |
72 | ||
73 | static DEFINE_RWLOCK(instances_lock); | |
74 | ||
75 | u_int64_t htonll(u_int64_t in) | |
76 | { | |
77 | u_int64_t out; | |
78 | int i; | |
79 | ||
80 | for (i = 0; i < sizeof(u_int64_t); i++) | |
81 | ((u_int8_t *)&out)[sizeof(u_int64_t)-1] = ((u_int8_t *)&in)[i]; | |
82 | ||
83 | return out; | |
84 | } | |
85 | ||
86 | #define INSTANCE_BUCKETS 16 | |
87 | static struct hlist_head instance_table[INSTANCE_BUCKETS]; | |
88 | ||
89 | static inline u_int8_t instance_hashfn(u_int16_t queue_num) | |
90 | { | |
91 | return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS; | |
92 | } | |
93 | ||
94 | static struct nfqnl_instance * | |
95 | __instance_lookup(u_int16_t queue_num) | |
96 | { | |
97 | struct hlist_head *head; | |
98 | struct hlist_node *pos; | |
99 | struct nfqnl_instance *inst; | |
100 | ||
101 | head = &instance_table[instance_hashfn(queue_num)]; | |
102 | hlist_for_each_entry(inst, pos, head, hlist) { | |
103 | if (inst->queue_num == queue_num) | |
104 | return inst; | |
105 | } | |
106 | return NULL; | |
107 | } | |
108 | ||
109 | static struct nfqnl_instance * | |
838ab636 | 110 | instance_lookup_get(u_int16_t queue_num) |
7af4cc3f HW |
111 | { |
112 | struct nfqnl_instance *inst; | |
113 | ||
114 | read_lock_bh(&instances_lock); | |
115 | inst = __instance_lookup(queue_num); | |
838ab636 HW |
116 | if (inst) |
117 | atomic_inc(&inst->use); | |
7af4cc3f HW |
118 | read_unlock_bh(&instances_lock); |
119 | ||
120 | return inst; | |
121 | } | |
122 | ||
838ab636 HW |
123 | static void |
124 | instance_put(struct nfqnl_instance *inst) | |
125 | { | |
126 | if (inst && atomic_dec_and_test(&inst->use)) { | |
127 | QDEBUG("kfree(inst=%p)\n", inst); | |
128 | kfree(inst); | |
129 | } | |
130 | } | |
131 | ||
7af4cc3f HW |
132 | static struct nfqnl_instance * |
133 | instance_create(u_int16_t queue_num, int pid) | |
134 | { | |
135 | struct nfqnl_instance *inst; | |
136 | ||
137 | QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid); | |
138 | ||
139 | write_lock_bh(&instances_lock); | |
140 | if (__instance_lookup(queue_num)) { | |
141 | inst = NULL; | |
142 | QDEBUG("aborting, instance already exists\n"); | |
143 | goto out_unlock; | |
144 | } | |
145 | ||
146 | inst = kmalloc(sizeof(*inst), GFP_ATOMIC); | |
147 | if (!inst) | |
148 | goto out_unlock; | |
149 | ||
150 | memset(inst, 0, sizeof(*inst)); | |
151 | inst->queue_num = queue_num; | |
152 | inst->peer_pid = pid; | |
153 | inst->queue_maxlen = NFQNL_QMAX_DEFAULT; | |
154 | inst->copy_range = 0xfffff; | |
155 | inst->copy_mode = NFQNL_COPY_NONE; | |
156 | atomic_set(&inst->id_sequence, 0); | |
838ab636 HW |
157 | /* needs to be two, since we _put() after creation */ |
158 | atomic_set(&inst->use, 2); | |
7af4cc3f HW |
159 | inst->lock = SPIN_LOCK_UNLOCKED; |
160 | INIT_LIST_HEAD(&inst->queue_list); | |
161 | ||
162 | if (!try_module_get(THIS_MODULE)) | |
163 | goto out_free; | |
164 | ||
165 | hlist_add_head(&inst->hlist, | |
166 | &instance_table[instance_hashfn(queue_num)]); | |
167 | ||
168 | write_unlock_bh(&instances_lock); | |
169 | ||
170 | QDEBUG("successfully created new instance\n"); | |
171 | ||
172 | return inst; | |
173 | ||
174 | out_free: | |
175 | kfree(inst); | |
176 | out_unlock: | |
177 | write_unlock_bh(&instances_lock); | |
178 | return NULL; | |
179 | } | |
180 | ||
181 | static void nfqnl_flush(struct nfqnl_instance *queue, int verdict); | |
182 | ||
183 | static void | |
184 | _instance_destroy2(struct nfqnl_instance *inst, int lock) | |
185 | { | |
186 | /* first pull it out of the global list */ | |
187 | if (lock) | |
188 | write_lock_bh(&instances_lock); | |
189 | ||
190 | QDEBUG("removing instance %p (queuenum=%u) from hash\n", | |
191 | inst, inst->queue_num); | |
192 | hlist_del(&inst->hlist); | |
193 | ||
194 | if (lock) | |
195 | write_unlock_bh(&instances_lock); | |
196 | ||
197 | /* then flush all pending skbs from the queue */ | |
198 | nfqnl_flush(inst, NF_DROP); | |
199 | ||
838ab636 HW |
200 | /* and finally put the refcount */ |
201 | instance_put(inst); | |
7af4cc3f HW |
202 | |
203 | module_put(THIS_MODULE); | |
204 | } | |
205 | ||
206 | static inline void | |
207 | __instance_destroy(struct nfqnl_instance *inst) | |
208 | { | |
209 | _instance_destroy2(inst, 0); | |
210 | } | |
211 | ||
212 | static inline void | |
213 | instance_destroy(struct nfqnl_instance *inst) | |
214 | { | |
215 | _instance_destroy2(inst, 1); | |
216 | } | |
217 | ||
218 | ||
219 | ||
220 | static void | |
221 | issue_verdict(struct nfqnl_queue_entry *entry, int verdict) | |
222 | { | |
223 | QDEBUG("entering for entry %p, verdict %u\n", entry, verdict); | |
224 | ||
225 | /* TCP input path (and probably other bits) assume to be called | |
226 | * from softirq context, not from syscall, like issue_verdict is | |
227 | * called. TCP input path deadlocks with locks taken from timer | |
228 | * softirq, e.g. We therefore emulate this by local_bh_disable() */ | |
229 | ||
230 | local_bh_disable(); | |
231 | nf_reinject(entry->skb, entry->info, verdict); | |
232 | local_bh_enable(); | |
233 | ||
234 | kfree(entry); | |
235 | } | |
236 | ||
237 | static inline void | |
238 | __enqueue_entry(struct nfqnl_instance *queue, | |
239 | struct nfqnl_queue_entry *entry) | |
240 | { | |
241 | list_add(&entry->list, &queue->queue_list); | |
242 | queue->queue_total++; | |
243 | } | |
244 | ||
245 | /* | |
246 | * Find and return a queued entry matched by cmpfn, or return the last | |
247 | * entry if cmpfn is NULL. | |
248 | */ | |
249 | static inline struct nfqnl_queue_entry * | |
250 | __find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, | |
251 | unsigned long data) | |
252 | { | |
253 | struct list_head *p; | |
254 | ||
255 | list_for_each_prev(p, &queue->queue_list) { | |
256 | struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p; | |
257 | ||
258 | if (!cmpfn || cmpfn(entry, data)) | |
259 | return entry; | |
260 | } | |
261 | return NULL; | |
262 | } | |
263 | ||
264 | static inline void | |
265 | __dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry) | |
266 | { | |
267 | list_del(&entry->list); | |
268 | q->queue_total--; | |
269 | } | |
270 | ||
271 | static inline struct nfqnl_queue_entry * | |
272 | __find_dequeue_entry(struct nfqnl_instance *queue, | |
273 | nfqnl_cmpfn cmpfn, unsigned long data) | |
274 | { | |
275 | struct nfqnl_queue_entry *entry; | |
276 | ||
277 | entry = __find_entry(queue, cmpfn, data); | |
278 | if (entry == NULL) | |
279 | return NULL; | |
280 | ||
281 | __dequeue_entry(queue, entry); | |
282 | return entry; | |
283 | } | |
284 | ||
285 | ||
286 | static inline void | |
287 | __nfqnl_flush(struct nfqnl_instance *queue, int verdict) | |
288 | { | |
289 | struct nfqnl_queue_entry *entry; | |
290 | ||
291 | while ((entry = __find_dequeue_entry(queue, NULL, 0))) | |
292 | issue_verdict(entry, verdict); | |
293 | } | |
294 | ||
295 | static inline int | |
296 | __nfqnl_set_mode(struct nfqnl_instance *queue, | |
297 | unsigned char mode, unsigned int range) | |
298 | { | |
299 | int status = 0; | |
300 | ||
301 | switch (mode) { | |
302 | case NFQNL_COPY_NONE: | |
303 | case NFQNL_COPY_META: | |
304 | queue->copy_mode = mode; | |
305 | queue->copy_range = 0; | |
306 | break; | |
307 | ||
308 | case NFQNL_COPY_PACKET: | |
309 | queue->copy_mode = mode; | |
310 | /* we're using struct nfattr which has 16bit nfa_len */ | |
311 | if (range > 0xffff) | |
312 | queue->copy_range = 0xffff; | |
313 | else | |
314 | queue->copy_range = range; | |
315 | break; | |
316 | ||
317 | default: | |
318 | status = -EINVAL; | |
319 | ||
320 | } | |
321 | return status; | |
322 | } | |
323 | ||
324 | static struct nfqnl_queue_entry * | |
325 | find_dequeue_entry(struct nfqnl_instance *queue, | |
326 | nfqnl_cmpfn cmpfn, unsigned long data) | |
327 | { | |
328 | struct nfqnl_queue_entry *entry; | |
329 | ||
330 | spin_lock_bh(&queue->lock); | |
331 | entry = __find_dequeue_entry(queue, cmpfn, data); | |
332 | spin_unlock_bh(&queue->lock); | |
333 | ||
334 | return entry; | |
335 | } | |
336 | ||
337 | static void | |
338 | nfqnl_flush(struct nfqnl_instance *queue, int verdict) | |
339 | { | |
340 | spin_lock_bh(&queue->lock); | |
341 | __nfqnl_flush(queue, verdict); | |
342 | spin_unlock_bh(&queue->lock); | |
343 | } | |
344 | ||
345 | static struct sk_buff * | |
346 | nfqnl_build_packet_message(struct nfqnl_instance *queue, | |
347 | struct nfqnl_queue_entry *entry, int *errp) | |
348 | { | |
349 | unsigned char *old_tail; | |
350 | size_t size; | |
351 | size_t data_len = 0; | |
352 | struct sk_buff *skb; | |
353 | struct nfqnl_msg_packet_hdr pmsg; | |
354 | struct nlmsghdr *nlh; | |
355 | struct nfgenmsg *nfmsg; | |
356 | unsigned int tmp_uint; | |
357 | ||
358 | QDEBUG("entered\n"); | |
359 | ||
360 | /* all macros expand to constant values at compile time */ | |
361 | size = NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr)) | |
362 | + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
363 | + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
364 | + NLMSG_SPACE(sizeof(u_int32_t)) /* mark */ | |
365 | + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw)) | |
366 | + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp)); | |
367 | ||
368 | spin_lock_bh(&queue->lock); | |
369 | ||
370 | switch (queue->copy_mode) { | |
371 | case NFQNL_COPY_META: | |
372 | case NFQNL_COPY_NONE: | |
373 | data_len = 0; | |
374 | break; | |
375 | ||
376 | case NFQNL_COPY_PACKET: | |
377 | if (queue->copy_range == 0 | |
378 | || queue->copy_range > entry->skb->len) | |
379 | data_len = entry->skb->len; | |
380 | else | |
381 | data_len = queue->copy_range; | |
382 | ||
383 | size += NLMSG_SPACE(data_len); | |
384 | break; | |
385 | ||
386 | default: | |
387 | *errp = -EINVAL; | |
388 | spin_unlock_bh(&queue->lock); | |
389 | return NULL; | |
390 | } | |
391 | ||
392 | spin_unlock_bh(&queue->lock); | |
393 | ||
394 | skb = alloc_skb(size, GFP_ATOMIC); | |
395 | if (!skb) | |
396 | goto nlmsg_failure; | |
397 | ||
398 | old_tail= skb->tail; | |
399 | nlh = NLMSG_PUT(skb, 0, 0, | |
400 | NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, | |
401 | sizeof(struct nfgenmsg)); | |
402 | nfmsg = NLMSG_DATA(nlh); | |
403 | nfmsg->nfgen_family = entry->info->pf; | |
404 | nfmsg->version = NFNETLINK_V0; | |
405 | nfmsg->res_id = htons(queue->queue_num); | |
406 | ||
407 | pmsg.packet_id = htonl(entry->id); | |
408 | pmsg.hw_protocol = htons(entry->skb->protocol); | |
409 | pmsg.hook = entry->info->hook; | |
410 | ||
411 | NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg); | |
412 | ||
413 | if (entry->info->indev) { | |
414 | tmp_uint = htonl(entry->info->indev->ifindex); | |
415 | NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint); | |
416 | } | |
417 | ||
418 | if (entry->info->outdev) { | |
419 | tmp_uint = htonl(entry->info->outdev->ifindex); | |
420 | NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint); | |
421 | } | |
422 | ||
423 | if (entry->skb->nfmark) { | |
424 | tmp_uint = htonl(entry->skb->nfmark); | |
425 | NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint); | |
426 | } | |
427 | ||
428 | if (entry->info->indev && entry->skb->dev | |
429 | && entry->skb->dev->hard_header_parse) { | |
430 | struct nfqnl_msg_packet_hw phw; | |
431 | ||
432 | phw.hw_addrlen = | |
433 | entry->skb->dev->hard_header_parse(entry->skb, | |
434 | phw.hw_addr); | |
435 | phw.hw_addrlen = htons(phw.hw_addrlen); | |
436 | NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw); | |
437 | } | |
438 | ||
439 | if (entry->skb->stamp.tv_sec) { | |
440 | struct nfqnl_msg_packet_timestamp ts; | |
441 | ||
442 | ts.sec = htonll(entry->skb->stamp.tv_sec); | |
443 | ts.usec = htonll(entry->skb->stamp.tv_usec); | |
444 | ||
445 | NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts); | |
446 | } | |
447 | ||
448 | if (data_len) { | |
449 | struct nfattr *nfa; | |
450 | int size = NFA_LENGTH(data_len); | |
451 | ||
452 | if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) { | |
453 | printk(KERN_WARNING "nf_queue: no tailroom!\n"); | |
454 | goto nlmsg_failure; | |
455 | } | |
456 | ||
457 | nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size)); | |
458 | nfa->nfa_type = NFQA_PAYLOAD; | |
459 | nfa->nfa_len = size; | |
460 | ||
461 | if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len)) | |
462 | BUG(); | |
463 | } | |
464 | ||
465 | nlh->nlmsg_len = skb->tail - old_tail; | |
466 | return skb; | |
467 | ||
468 | nlmsg_failure: | |
469 | nfattr_failure: | |
470 | if (skb) | |
471 | kfree_skb(skb); | |
472 | *errp = -EINVAL; | |
473 | if (net_ratelimit()) | |
474 | printk(KERN_ERR "nf_queue: error creating packet message\n"); | |
475 | return NULL; | |
476 | } | |
477 | ||
478 | static int | |
479 | nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info, | |
480 | unsigned int queuenum, void *data) | |
481 | { | |
482 | int status = -EINVAL; | |
483 | struct sk_buff *nskb; | |
484 | struct nfqnl_instance *queue; | |
485 | struct nfqnl_queue_entry *entry; | |
486 | ||
487 | QDEBUG("entered\n"); | |
488 | ||
838ab636 | 489 | queue = instance_lookup_get(queuenum); |
7af4cc3f HW |
490 | if (!queue) { |
491 | QDEBUG("no queue instance matching\n"); | |
492 | return -EINVAL; | |
493 | } | |
494 | ||
495 | if (queue->copy_mode == NFQNL_COPY_NONE) { | |
496 | QDEBUG("mode COPY_NONE, aborting\n"); | |
838ab636 HW |
497 | status = -EAGAIN; |
498 | goto err_out_put; | |
7af4cc3f HW |
499 | } |
500 | ||
501 | entry = kmalloc(sizeof(*entry), GFP_ATOMIC); | |
502 | if (entry == NULL) { | |
503 | if (net_ratelimit()) | |
504 | printk(KERN_ERR | |
505 | "nf_queue: OOM in nfqnl_enqueue_packet()\n"); | |
838ab636 HW |
506 | status = -ENOMEM; |
507 | goto err_out_put; | |
7af4cc3f HW |
508 | } |
509 | ||
510 | entry->info = info; | |
511 | entry->skb = skb; | |
512 | entry->id = atomic_inc_return(&queue->id_sequence); | |
513 | ||
514 | nskb = nfqnl_build_packet_message(queue, entry, &status); | |
515 | if (nskb == NULL) | |
516 | goto err_out_free; | |
517 | ||
518 | spin_lock_bh(&queue->lock); | |
519 | ||
520 | if (!queue->peer_pid) | |
521 | goto err_out_free_nskb; | |
522 | ||
523 | if (queue->queue_total >= queue->queue_maxlen) { | |
524 | queue->queue_dropped++; | |
525 | status = -ENOSPC; | |
526 | if (net_ratelimit()) | |
527 | printk(KERN_WARNING "ip_queue: full at %d entries, " | |
528 | "dropping packets(s). Dropped: %d\n", | |
529 | queue->queue_total, queue->queue_dropped); | |
530 | goto err_out_free_nskb; | |
531 | } | |
532 | ||
533 | /* nfnetlink_unicast will either free the nskb or add it to a socket */ | |
534 | status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT); | |
535 | if (status < 0) { | |
536 | queue->queue_user_dropped++; | |
537 | goto err_out_unlock; | |
538 | } | |
539 | ||
540 | __enqueue_entry(queue, entry); | |
541 | ||
542 | spin_unlock_bh(&queue->lock); | |
838ab636 | 543 | instance_put(queue); |
7af4cc3f HW |
544 | return status; |
545 | ||
546 | err_out_free_nskb: | |
547 | kfree_skb(nskb); | |
548 | ||
549 | err_out_unlock: | |
550 | spin_unlock_bh(&queue->lock); | |
551 | ||
552 | err_out_free: | |
553 | kfree(entry); | |
838ab636 HW |
554 | err_out_put: |
555 | instance_put(queue); | |
7af4cc3f HW |
556 | return status; |
557 | } | |
558 | ||
559 | static int | |
560 | nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e) | |
561 | { | |
562 | int diff; | |
563 | ||
564 | diff = data_len - e->skb->len; | |
565 | if (diff < 0) | |
566 | skb_trim(e->skb, data_len); | |
567 | else if (diff > 0) { | |
568 | if (data_len > 0xFFFF) | |
569 | return -EINVAL; | |
570 | if (diff > skb_tailroom(e->skb)) { | |
571 | struct sk_buff *newskb; | |
572 | ||
573 | newskb = skb_copy_expand(e->skb, | |
574 | skb_headroom(e->skb), | |
575 | diff, | |
576 | GFP_ATOMIC); | |
577 | if (newskb == NULL) { | |
578 | printk(KERN_WARNING "ip_queue: OOM " | |
579 | "in mangle, dropping packet\n"); | |
580 | return -ENOMEM; | |
581 | } | |
582 | if (e->skb->sk) | |
583 | skb_set_owner_w(newskb, e->skb->sk); | |
584 | kfree_skb(e->skb); | |
585 | e->skb = newskb; | |
586 | } | |
587 | skb_put(e->skb, diff); | |
588 | } | |
589 | if (!skb_make_writable(&e->skb, data_len)) | |
590 | return -ENOMEM; | |
591 | memcpy(e->skb->data, data, data_len); | |
592 | ||
593 | return 0; | |
594 | } | |
595 | ||
596 | static inline int | |
597 | id_cmp(struct nfqnl_queue_entry *e, unsigned long id) | |
598 | { | |
599 | return (id == e->id); | |
600 | } | |
601 | ||
602 | static int | |
603 | nfqnl_set_mode(struct nfqnl_instance *queue, | |
604 | unsigned char mode, unsigned int range) | |
605 | { | |
606 | int status; | |
607 | ||
608 | spin_lock_bh(&queue->lock); | |
609 | status = __nfqnl_set_mode(queue, mode, range); | |
610 | spin_unlock_bh(&queue->lock); | |
611 | ||
612 | return status; | |
613 | } | |
614 | ||
615 | static int | |
616 | dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex) | |
617 | { | |
618 | if (entry->info->indev) | |
619 | if (entry->info->indev->ifindex == ifindex) | |
620 | return 1; | |
621 | ||
622 | if (entry->info->outdev) | |
623 | if (entry->info->outdev->ifindex == ifindex) | |
624 | return 1; | |
625 | ||
626 | return 0; | |
627 | } | |
628 | ||
629 | /* drop all packets with either indev or outdev == ifindex from all queue | |
630 | * instances */ | |
631 | static void | |
632 | nfqnl_dev_drop(int ifindex) | |
633 | { | |
634 | int i; | |
635 | ||
636 | QDEBUG("entering for ifindex %u\n", ifindex); | |
637 | ||
638 | /* this only looks like we have to hold the readlock for a way too long | |
639 | * time, issue_verdict(), nf_reinject(), ... - but we always only | |
640 | * issue NF_DROP, which is processed directly in nf_reinject() */ | |
641 | read_lock_bh(&instances_lock); | |
642 | ||
643 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
644 | struct hlist_node *tmp; | |
645 | struct nfqnl_instance *inst; | |
646 | struct hlist_head *head = &instance_table[i]; | |
647 | ||
648 | hlist_for_each_entry(inst, tmp, head, hlist) { | |
649 | struct nfqnl_queue_entry *entry; | |
650 | while ((entry = find_dequeue_entry(inst, dev_cmp, | |
651 | ifindex)) != NULL) | |
652 | issue_verdict(entry, NF_DROP); | |
653 | } | |
654 | } | |
655 | ||
656 | read_unlock_bh(&instances_lock); | |
657 | } | |
658 | ||
659 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
660 | ||
661 | static int | |
662 | nfqnl_rcv_dev_event(struct notifier_block *this, | |
663 | unsigned long event, void *ptr) | |
664 | { | |
665 | struct net_device *dev = ptr; | |
666 | ||
667 | /* Drop any packets associated with the downed device */ | |
668 | if (event == NETDEV_DOWN) | |
669 | nfqnl_dev_drop(dev->ifindex); | |
670 | return NOTIFY_DONE; | |
671 | } | |
672 | ||
673 | static struct notifier_block nfqnl_dev_notifier = { | |
674 | .notifier_call = nfqnl_rcv_dev_event, | |
675 | }; | |
676 | ||
677 | static int | |
678 | nfqnl_rcv_nl_event(struct notifier_block *this, | |
679 | unsigned long event, void *ptr) | |
680 | { | |
681 | struct netlink_notify *n = ptr; | |
682 | ||
683 | if (event == NETLINK_URELEASE && | |
684 | n->protocol == NETLINK_NETFILTER && n->pid) { | |
685 | int i; | |
686 | ||
687 | /* destroy all instances for this pid */ | |
688 | write_lock_bh(&instances_lock); | |
689 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
690 | struct hlist_node *tmp, *t2; | |
691 | struct nfqnl_instance *inst; | |
692 | struct hlist_head *head = &instance_table[i]; | |
693 | ||
694 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { | |
695 | if (n->pid == inst->peer_pid) | |
696 | __instance_destroy(inst); | |
697 | } | |
698 | } | |
699 | write_unlock_bh(&instances_lock); | |
700 | } | |
701 | return NOTIFY_DONE; | |
702 | } | |
703 | ||
704 | static struct notifier_block nfqnl_rtnl_notifier = { | |
705 | .notifier_call = nfqnl_rcv_nl_event, | |
706 | }; | |
707 | ||
838ab636 HW |
708 | static const int nfqa_verdict_min[NFQA_MAX] = { |
709 | [NFQA_VERDICT_HDR-1] = sizeof(struct nfqnl_msg_verdict_hdr), | |
710 | [NFQA_MARK-1] = sizeof(u_int32_t), | |
711 | [NFQA_PAYLOAD-1] = 0, | |
712 | }; | |
713 | ||
7af4cc3f HW |
714 | static int |
715 | nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, | |
716 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
717 | { | |
718 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
719 | u_int16_t queue_num = ntohs(nfmsg->res_id); | |
720 | ||
721 | struct nfqnl_msg_verdict_hdr *vhdr; | |
722 | struct nfqnl_instance *queue; | |
723 | unsigned int verdict; | |
724 | struct nfqnl_queue_entry *entry; | |
838ab636 | 725 | int err; |
7af4cc3f | 726 | |
838ab636 HW |
727 | if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) { |
728 | QDEBUG("bad attribute size\n"); | |
729 | return -EINVAL; | |
730 | } | |
731 | ||
732 | queue = instance_lookup_get(queue_num); | |
7af4cc3f HW |
733 | if (!queue) |
734 | return -ENODEV; | |
735 | ||
838ab636 HW |
736 | if (queue->peer_pid != NETLINK_CB(skb).pid) { |
737 | err = -EPERM; | |
738 | goto err_out_put; | |
739 | } | |
7af4cc3f | 740 | |
838ab636 HW |
741 | if (!nfqa[NFQA_VERDICT_HDR-1]) { |
742 | err = -EINVAL; | |
743 | goto err_out_put; | |
744 | } | |
7af4cc3f HW |
745 | |
746 | vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]); | |
747 | verdict = ntohl(vhdr->verdict); | |
748 | ||
838ab636 HW |
749 | if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) { |
750 | err = -EINVAL; | |
751 | goto err_out_put; | |
752 | } | |
7af4cc3f HW |
753 | |
754 | entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id)); | |
838ab636 HW |
755 | if (entry == NULL) { |
756 | err = -ENOENT; | |
757 | goto err_out_put; | |
758 | } | |
7af4cc3f HW |
759 | |
760 | if (nfqa[NFQA_PAYLOAD-1]) { | |
761 | if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]), | |
762 | NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0) | |
763 | verdict = NF_DROP; | |
764 | } | |
765 | ||
766 | if (nfqa[NFQA_MARK-1]) | |
767 | skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1])); | |
768 | ||
769 | issue_verdict(entry, verdict); | |
838ab636 | 770 | instance_put(queue); |
7af4cc3f | 771 | return 0; |
838ab636 HW |
772 | |
773 | err_out_put: | |
774 | instance_put(queue); | |
775 | return err; | |
7af4cc3f HW |
776 | } |
777 | ||
778 | static int | |
779 | nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, | |
780 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
781 | { | |
782 | return -ENOTSUPP; | |
783 | } | |
784 | ||
838ab636 HW |
785 | static const int nfqa_cfg_min[NFQA_CFG_MAX] = { |
786 | [NFQA_CFG_CMD-1] = sizeof(struct nfqnl_msg_config_cmd), | |
787 | [NFQA_CFG_PARAMS-1] = sizeof(struct nfqnl_msg_config_params), | |
788 | }; | |
789 | ||
7af4cc3f HW |
790 | static int |
791 | nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb, | |
792 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
793 | { | |
794 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
795 | u_int16_t queue_num = ntohs(nfmsg->res_id); | |
796 | struct nfqnl_instance *queue; | |
838ab636 | 797 | int ret = 0; |
7af4cc3f HW |
798 | |
799 | QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); | |
800 | ||
838ab636 HW |
801 | if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) { |
802 | QDEBUG("bad attribute size\n"); | |
803 | return -EINVAL; | |
804 | } | |
805 | ||
806 | queue = instance_lookup_get(queue_num); | |
7af4cc3f HW |
807 | if (nfqa[NFQA_CFG_CMD-1]) { |
808 | struct nfqnl_msg_config_cmd *cmd; | |
809 | cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]); | |
810 | QDEBUG("found CFG_CMD\n"); | |
811 | ||
812 | switch (cmd->command) { | |
813 | case NFQNL_CFG_CMD_BIND: | |
814 | if (queue) | |
815 | return -EBUSY; | |
816 | ||
817 | queue = instance_create(queue_num, NETLINK_CB(skb).pid); | |
818 | if (!queue) | |
819 | return -EINVAL; | |
820 | break; | |
821 | case NFQNL_CFG_CMD_UNBIND: | |
822 | if (!queue) | |
823 | return -ENODEV; | |
824 | ||
838ab636 HW |
825 | if (queue->peer_pid != NETLINK_CB(skb).pid) { |
826 | ret = -EPERM; | |
827 | goto out_put; | |
828 | } | |
7af4cc3f HW |
829 | |
830 | instance_destroy(queue); | |
831 | break; | |
832 | case NFQNL_CFG_CMD_PF_BIND: | |
833 | QDEBUG("registering queue handler for pf=%u\n", | |
834 | ntohs(cmd->pf)); | |
838ab636 HW |
835 | ret = nf_register_queue_handler(ntohs(cmd->pf), |
836 | nfqnl_enqueue_packet, | |
837 | NULL); | |
7af4cc3f HW |
838 | |
839 | break; | |
840 | case NFQNL_CFG_CMD_PF_UNBIND: | |
841 | QDEBUG("unregistering queue handler for pf=%u\n", | |
842 | ntohs(cmd->pf)); | |
843 | /* This is a bug and a feature. We can unregister | |
844 | * other handlers(!) */ | |
838ab636 | 845 | ret = nf_unregister_queue_handler(ntohs(cmd->pf)); |
7af4cc3f HW |
846 | break; |
847 | default: | |
838ab636 HW |
848 | ret = -EINVAL; |
849 | break; | |
7af4cc3f HW |
850 | } |
851 | } else { | |
852 | if (!queue) { | |
853 | QDEBUG("no config command, and no instance ENOENT\n"); | |
838ab636 HW |
854 | ret = -ENOENT; |
855 | goto out_put; | |
7af4cc3f HW |
856 | } |
857 | ||
858 | if (queue->peer_pid != NETLINK_CB(skb).pid) { | |
859 | QDEBUG("no config command, and wrong pid\n"); | |
838ab636 HW |
860 | ret = -EPERM; |
861 | goto out_put; | |
7af4cc3f HW |
862 | } |
863 | } | |
864 | ||
865 | if (nfqa[NFQA_CFG_PARAMS-1]) { | |
866 | struct nfqnl_msg_config_params *params; | |
867 | params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]); | |
868 | ||
869 | nfqnl_set_mode(queue, params->copy_mode, | |
870 | ntohl(params->copy_range)); | |
871 | } | |
872 | ||
838ab636 HW |
873 | out_put: |
874 | instance_put(queue); | |
875 | return ret; | |
7af4cc3f HW |
876 | } |
877 | ||
878 | static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { | |
879 | [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, | |
880 | .cap_required = CAP_NET_ADMIN }, | |
881 | [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, | |
882 | .cap_required = CAP_NET_ADMIN }, | |
883 | [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, | |
884 | .cap_required = CAP_NET_ADMIN }, | |
885 | }; | |
886 | ||
887 | static struct nfnetlink_subsystem nfqnl_subsys = { | |
888 | .name = "nf_queue", | |
889 | .subsys_id = NFNL_SUBSYS_QUEUE, | |
890 | .cb_count = NFQNL_MSG_MAX, | |
891 | .attr_count = NFQA_MAX, | |
892 | .cb = nfqnl_cb, | |
893 | }; | |
894 | ||
838ab636 HW |
895 | #ifdef CONFIG_PROC_FS |
896 | struct iter_state { | |
897 | unsigned int bucket; | |
898 | }; | |
899 | ||
900 | static struct hlist_node *get_first(struct seq_file *seq) | |
901 | { | |
902 | struct iter_state *st = seq->private; | |
903 | ||
904 | if (!st) | |
905 | return NULL; | |
906 | ||
907 | for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { | |
908 | if (!hlist_empty(&instance_table[st->bucket])) | |
909 | return instance_table[st->bucket].first; | |
910 | } | |
911 | return NULL; | |
912 | } | |
913 | ||
914 | static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) | |
915 | { | |
916 | struct iter_state *st = seq->private; | |
917 | ||
918 | h = h->next; | |
919 | while (!h) { | |
920 | if (++st->bucket >= INSTANCE_BUCKETS) | |
921 | return NULL; | |
922 | ||
923 | h = instance_table[st->bucket].first; | |
924 | } | |
925 | return h; | |
926 | } | |
927 | ||
928 | static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) | |
929 | { | |
930 | struct hlist_node *head; | |
931 | head = get_first(seq); | |
932 | ||
933 | if (head) | |
934 | while (pos && (head = get_next(seq, head))) | |
935 | pos--; | |
936 | return pos ? NULL : head; | |
937 | } | |
938 | ||
939 | static void *seq_start(struct seq_file *seq, loff_t *pos) | |
940 | { | |
941 | read_lock_bh(&instances_lock); | |
942 | return get_idx(seq, *pos); | |
943 | } | |
944 | ||
945 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) | |
946 | { | |
947 | (*pos)++; | |
948 | return get_next(s, v); | |
949 | } | |
950 | ||
951 | static void seq_stop(struct seq_file *s, void *v) | |
952 | { | |
953 | read_unlock_bh(&instances_lock); | |
954 | } | |
955 | ||
956 | static int seq_show(struct seq_file *s, void *v) | |
957 | { | |
958 | const struct nfqnl_instance *inst = v; | |
959 | ||
960 | return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n", | |
961 | inst->queue_num, | |
962 | inst->peer_pid, inst->queue_total, | |
963 | inst->copy_mode, inst->copy_range, | |
964 | inst->queue_dropped, inst->queue_user_dropped, | |
965 | atomic_read(&inst->id_sequence), | |
966 | atomic_read(&inst->use)); | |
967 | } | |
968 | ||
969 | static struct seq_operations nfqnl_seq_ops = { | |
970 | .start = seq_start, | |
971 | .next = seq_next, | |
972 | .stop = seq_stop, | |
973 | .show = seq_show, | |
974 | }; | |
975 | ||
976 | static int nfqnl_open(struct inode *inode, struct file *file) | |
977 | { | |
978 | struct seq_file *seq; | |
979 | struct iter_state *is; | |
980 | int ret; | |
981 | ||
982 | is = kmalloc(sizeof(*is), GFP_KERNEL); | |
983 | if (!is) | |
984 | return -ENOMEM; | |
985 | memset(is, 0, sizeof(*is)); | |
986 | ret = seq_open(file, &nfqnl_seq_ops); | |
987 | if (ret < 0) | |
988 | goto out_free; | |
989 | seq = file->private_data; | |
990 | seq->private = is; | |
991 | return ret; | |
992 | out_free: | |
993 | kfree(is); | |
994 | return ret; | |
995 | } | |
996 | ||
997 | static struct file_operations nfqnl_file_ops = { | |
998 | .owner = THIS_MODULE, | |
999 | .open = nfqnl_open, | |
1000 | .read = seq_read, | |
1001 | .llseek = seq_lseek, | |
1002 | .release = seq_release_private, | |
1003 | }; | |
1004 | ||
1005 | #endif /* PROC_FS */ | |
1006 | ||
7af4cc3f HW |
1007 | static int |
1008 | init_or_cleanup(int init) | |
1009 | { | |
838ab636 HW |
1010 | int i, status = -ENOMEM; |
1011 | #ifdef CONFIG_PROC_FS | |
1012 | struct proc_dir_entry *proc_nfqueue; | |
1013 | #endif | |
7af4cc3f HW |
1014 | |
1015 | if (!init) | |
1016 | goto cleanup; | |
1017 | ||
838ab636 HW |
1018 | for (i = 0; i < INSTANCE_BUCKETS; i++) |
1019 | INIT_HLIST_HEAD(&instance_table[i]); | |
1020 | ||
7af4cc3f HW |
1021 | netlink_register_notifier(&nfqnl_rtnl_notifier); |
1022 | status = nfnetlink_subsys_register(&nfqnl_subsys); | |
1023 | if (status < 0) { | |
1024 | printk(KERN_ERR "nf_queue: failed to create netlink socket\n"); | |
1025 | goto cleanup_netlink_notifier; | |
1026 | } | |
1027 | ||
838ab636 HW |
1028 | #ifdef CONFIG_PROC_FS |
1029 | proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440, | |
1030 | proc_net_netfilter); | |
1031 | if (!proc_nfqueue) | |
1032 | goto cleanup_subsys; | |
1033 | proc_nfqueue->proc_fops = &nfqnl_file_ops; | |
1034 | #endif | |
1035 | ||
7af4cc3f | 1036 | register_netdevice_notifier(&nfqnl_dev_notifier); |
838ab636 | 1037 | |
7af4cc3f HW |
1038 | return status; |
1039 | ||
1040 | cleanup: | |
1041 | nf_unregister_queue_handlers(nfqnl_enqueue_packet); | |
1042 | unregister_netdevice_notifier(&nfqnl_dev_notifier); | |
838ab636 HW |
1043 | #ifdef CONFIG_PROC_FS |
1044 | cleanup_subsys: | |
1045 | #endif | |
7af4cc3f | 1046 | nfnetlink_subsys_unregister(&nfqnl_subsys); |
7af4cc3f HW |
1047 | cleanup_netlink_notifier: |
1048 | netlink_unregister_notifier(&nfqnl_rtnl_notifier); | |
1049 | return status; | |
1050 | } | |
1051 | ||
1052 | static int __init init(void) | |
1053 | { | |
1054 | ||
1055 | return init_or_cleanup(1); | |
1056 | } | |
1057 | ||
1058 | static void __exit fini(void) | |
1059 | { | |
1060 | init_or_cleanup(0); | |
1061 | } | |
1062 | ||
1063 | MODULE_DESCRIPTION("netfilter packet queue handler"); | |
1064 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
1065 | MODULE_LICENSE("GPL"); | |
1066 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE); | |
1067 | ||
1068 | module_init(init); | |
1069 | module_exit(fini); |