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[deliverable/linux.git] / net / netfilter / nfnetlink_queue_core.c
1 /*
2 * This is a module which is used for queueing packets and communicating with
3 * userspace via nfnetlink.
4 *
5 * (C) 2005 by Harald Welte <laforge@netfilter.org>
6 * (C) 2007 by Patrick McHardy <kaber@trash.net>
7 *
8 * Based on the old ipv4-only ip_queue.c:
9 * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
10 * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 *
16 */
17 #include <linux/module.h>
18 #include <linux/skbuff.h>
19 #include <linux/init.h>
20 #include <linux/spinlock.h>
21 #include <linux/slab.h>
22 #include <linux/notifier.h>
23 #include <linux/netdevice.h>
24 #include <linux/netfilter.h>
25 #include <linux/proc_fs.h>
26 #include <linux/netfilter_ipv4.h>
27 #include <linux/netfilter_ipv6.h>
28 #include <linux/netfilter/nfnetlink.h>
29 #include <linux/netfilter/nfnetlink_queue.h>
30 #include <linux/list.h>
31 #include <net/sock.h>
32 #include <net/netfilter/nf_queue.h>
33 #include <net/netns/generic.h>
34 #include <net/netfilter/nfnetlink_queue.h>
35
36 #include <linux/atomic.h>
37
38 #ifdef CONFIG_BRIDGE_NETFILTER
39 #include "../bridge/br_private.h"
40 #endif
41
42 #define NFQNL_QMAX_DEFAULT 1024
43
44 struct nfqnl_instance {
45 struct hlist_node hlist; /* global list of queues */
46 struct rcu_head rcu;
47
48 int peer_portid;
49 unsigned int queue_maxlen;
50 unsigned int copy_range;
51 unsigned int queue_dropped;
52 unsigned int queue_user_dropped;
53
54
55 u_int16_t queue_num; /* number of this queue */
56 u_int8_t copy_mode;
57 u_int32_t flags; /* Set using NFQA_CFG_FLAGS */
58 /*
59 * Following fields are dirtied for each queued packet,
60 * keep them in same cache line if possible.
61 */
62 spinlock_t lock;
63 unsigned int queue_total;
64 unsigned int id_sequence; /* 'sequence' of pkt ids */
65 struct list_head queue_list; /* packets in queue */
66 };
67
68 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
69
70 static int nfnl_queue_net_id __read_mostly;
71
72 #define INSTANCE_BUCKETS 16
73 struct nfnl_queue_net {
74 spinlock_t instances_lock;
75 struct hlist_head instance_table[INSTANCE_BUCKETS];
76 };
77
78 static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net)
79 {
80 return net_generic(net, nfnl_queue_net_id);
81 }
82
83 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
84 {
85 return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS;
86 }
87
88 static struct nfqnl_instance *
89 instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num)
90 {
91 struct hlist_head *head;
92 struct nfqnl_instance *inst;
93
94 head = &q->instance_table[instance_hashfn(queue_num)];
95 hlist_for_each_entry_rcu(inst, head, hlist) {
96 if (inst->queue_num == queue_num)
97 return inst;
98 }
99 return NULL;
100 }
101
102 static struct nfqnl_instance *
103 instance_create(struct nfnl_queue_net *q, u_int16_t queue_num,
104 int portid)
105 {
106 struct nfqnl_instance *inst;
107 unsigned int h;
108 int err;
109
110 spin_lock(&q->instances_lock);
111 if (instance_lookup(q, queue_num)) {
112 err = -EEXIST;
113 goto out_unlock;
114 }
115
116 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
117 if (!inst) {
118 err = -ENOMEM;
119 goto out_unlock;
120 }
121
122 inst->queue_num = queue_num;
123 inst->peer_portid = portid;
124 inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
125 inst->copy_range = 0xffff;
126 inst->copy_mode = NFQNL_COPY_NONE;
127 spin_lock_init(&inst->lock);
128 INIT_LIST_HEAD(&inst->queue_list);
129
130 if (!try_module_get(THIS_MODULE)) {
131 err = -EAGAIN;
132 goto out_free;
133 }
134
135 h = instance_hashfn(queue_num);
136 hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]);
137
138 spin_unlock(&q->instances_lock);
139
140 return inst;
141
142 out_free:
143 kfree(inst);
144 out_unlock:
145 spin_unlock(&q->instances_lock);
146 return ERR_PTR(err);
147 }
148
149 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
150 unsigned long data);
151
152 static void
153 instance_destroy_rcu(struct rcu_head *head)
154 {
155 struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
156 rcu);
157
158 nfqnl_flush(inst, NULL, 0);
159 kfree(inst);
160 module_put(THIS_MODULE);
161 }
162
163 static void
164 __instance_destroy(struct nfqnl_instance *inst)
165 {
166 hlist_del_rcu(&inst->hlist);
167 call_rcu(&inst->rcu, instance_destroy_rcu);
168 }
169
170 static void
171 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
172 {
173 spin_lock(&q->instances_lock);
174 __instance_destroy(inst);
175 spin_unlock(&q->instances_lock);
176 }
177
178 static inline void
179 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
180 {
181 list_add_tail(&entry->list, &queue->queue_list);
182 queue->queue_total++;
183 }
184
185 static void
186 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
187 {
188 list_del(&entry->list);
189 queue->queue_total--;
190 }
191
192 static struct nf_queue_entry *
193 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
194 {
195 struct nf_queue_entry *entry = NULL, *i;
196
197 spin_lock_bh(&queue->lock);
198
199 list_for_each_entry(i, &queue->queue_list, list) {
200 if (i->id == id) {
201 entry = i;
202 break;
203 }
204 }
205
206 if (entry)
207 __dequeue_entry(queue, entry);
208
209 spin_unlock_bh(&queue->lock);
210
211 return entry;
212 }
213
214 static void
215 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
216 {
217 struct nf_queue_entry *entry, *next;
218
219 spin_lock_bh(&queue->lock);
220 list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
221 if (!cmpfn || cmpfn(entry, data)) {
222 list_del(&entry->list);
223 queue->queue_total--;
224 nf_reinject(entry, NF_DROP);
225 }
226 }
227 spin_unlock_bh(&queue->lock);
228 }
229
230 static void
231 nfqnl_zcopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
232 {
233 int i, j = 0;
234 int plen = 0; /* length of skb->head fragment */
235 struct page *page;
236 unsigned int offset;
237
238 /* dont bother with small payloads */
239 if (len <= skb_tailroom(to)) {
240 skb_copy_bits(from, 0, skb_put(to, len), len);
241 return;
242 }
243
244 if (hlen) {
245 skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
246 len -= hlen;
247 } else {
248 plen = min_t(int, skb_headlen(from), len);
249 if (plen) {
250 page = virt_to_head_page(from->head);
251 offset = from->data - (unsigned char *)page_address(page);
252 __skb_fill_page_desc(to, 0, page, offset, plen);
253 get_page(page);
254 j = 1;
255 len -= plen;
256 }
257 }
258
259 to->truesize += len + plen;
260 to->len += len + plen;
261 to->data_len += len + plen;
262
263 for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
264 if (!len)
265 break;
266 skb_shinfo(to)->frags[j] = skb_shinfo(from)->frags[i];
267 skb_shinfo(to)->frags[j].size = min_t(int, skb_shinfo(to)->frags[j].size, len);
268 len -= skb_shinfo(to)->frags[j].size;
269 skb_frag_ref(to, j);
270 j++;
271 }
272 skb_shinfo(to)->nr_frags = j;
273 }
274
275 static struct sk_buff *
276 nfqnl_build_packet_message(struct nfqnl_instance *queue,
277 struct nf_queue_entry *entry,
278 __be32 **packet_id_ptr)
279 {
280 size_t size;
281 size_t data_len = 0, cap_len = 0;
282 int hlen = 0;
283 struct sk_buff *skb;
284 struct nlattr *nla;
285 struct nfqnl_msg_packet_hdr *pmsg;
286 struct nlmsghdr *nlh;
287 struct nfgenmsg *nfmsg;
288 struct sk_buff *entskb = entry->skb;
289 struct net_device *indev;
290 struct net_device *outdev;
291 struct nf_conn *ct = NULL;
292 enum ip_conntrack_info uninitialized_var(ctinfo);
293
294 size = nlmsg_total_size(sizeof(struct nfgenmsg))
295 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
296 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
297 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
298 #ifdef CONFIG_BRIDGE_NETFILTER
299 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
300 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
301 #endif
302 + nla_total_size(sizeof(u_int32_t)) /* mark */
303 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
304 + nla_total_size(sizeof(u_int32_t)); /* cap_len */
305
306 if (entskb->tstamp.tv64)
307 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
308
309 outdev = entry->outdev;
310
311 switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) {
312 case NFQNL_COPY_META:
313 case NFQNL_COPY_NONE:
314 break;
315
316 case NFQNL_COPY_PACKET:
317 if (entskb->ip_summed == CHECKSUM_PARTIAL &&
318 skb_checksum_help(entskb))
319 return NULL;
320
321 data_len = ACCESS_ONCE(queue->copy_range);
322 if (data_len == 0 || data_len > entskb->len)
323 data_len = entskb->len;
324
325
326 if (!entskb->head_frag ||
327 skb_headlen(entskb) < L1_CACHE_BYTES ||
328 skb_shinfo(entskb)->nr_frags >= MAX_SKB_FRAGS)
329 hlen = skb_headlen(entskb);
330
331 if (skb_has_frag_list(entskb))
332 hlen = entskb->len;
333 hlen = min_t(int, data_len, hlen);
334 size += sizeof(struct nlattr) + hlen;
335 cap_len = entskb->len;
336 break;
337 }
338
339 if (queue->flags & NFQA_CFG_F_CONNTRACK)
340 ct = nfqnl_ct_get(entskb, &size, &ctinfo);
341
342 skb = nfnetlink_alloc_skb(&init_net, size, queue->peer_portid,
343 GFP_ATOMIC);
344 if (!skb)
345 return NULL;
346
347 nlh = nlmsg_put(skb, 0, 0,
348 NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
349 sizeof(struct nfgenmsg), 0);
350 if (!nlh) {
351 kfree_skb(skb);
352 return NULL;
353 }
354 nfmsg = nlmsg_data(nlh);
355 nfmsg->nfgen_family = entry->pf;
356 nfmsg->version = NFNETLINK_V0;
357 nfmsg->res_id = htons(queue->queue_num);
358
359 nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
360 pmsg = nla_data(nla);
361 pmsg->hw_protocol = entskb->protocol;
362 pmsg->hook = entry->hook;
363 *packet_id_ptr = &pmsg->packet_id;
364
365 indev = entry->indev;
366 if (indev) {
367 #ifndef CONFIG_BRIDGE_NETFILTER
368 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
369 goto nla_put_failure;
370 #else
371 if (entry->pf == PF_BRIDGE) {
372 /* Case 1: indev is physical input device, we need to
373 * look for bridge group (when called from
374 * netfilter_bridge) */
375 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
376 htonl(indev->ifindex)) ||
377 /* this is the bridge group "brX" */
378 /* rcu_read_lock()ed by __nf_queue */
379 nla_put_be32(skb, NFQA_IFINDEX_INDEV,
380 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
381 goto nla_put_failure;
382 } else {
383 /* Case 2: indev is bridge group, we need to look for
384 * physical device (when called from ipv4) */
385 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
386 htonl(indev->ifindex)))
387 goto nla_put_failure;
388 if (entskb->nf_bridge && entskb->nf_bridge->physindev &&
389 nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
390 htonl(entskb->nf_bridge->physindev->ifindex)))
391 goto nla_put_failure;
392 }
393 #endif
394 }
395
396 if (outdev) {
397 #ifndef CONFIG_BRIDGE_NETFILTER
398 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
399 goto nla_put_failure;
400 #else
401 if (entry->pf == PF_BRIDGE) {
402 /* Case 1: outdev is physical output device, we need to
403 * look for bridge group (when called from
404 * netfilter_bridge) */
405 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
406 htonl(outdev->ifindex)) ||
407 /* this is the bridge group "brX" */
408 /* rcu_read_lock()ed by __nf_queue */
409 nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
410 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
411 goto nla_put_failure;
412 } else {
413 /* Case 2: outdev is bridge group, we need to look for
414 * physical output device (when called from ipv4) */
415 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
416 htonl(outdev->ifindex)))
417 goto nla_put_failure;
418 if (entskb->nf_bridge && entskb->nf_bridge->physoutdev &&
419 nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
420 htonl(entskb->nf_bridge->physoutdev->ifindex)))
421 goto nla_put_failure;
422 }
423 #endif
424 }
425
426 if (entskb->mark &&
427 nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
428 goto nla_put_failure;
429
430 if (indev && entskb->dev &&
431 entskb->mac_header != entskb->network_header) {
432 struct nfqnl_msg_packet_hw phw;
433 int len = dev_parse_header(entskb, phw.hw_addr);
434 if (len) {
435 phw.hw_addrlen = htons(len);
436 if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
437 goto nla_put_failure;
438 }
439 }
440
441 if (entskb->tstamp.tv64) {
442 struct nfqnl_msg_packet_timestamp ts;
443 struct timeval tv = ktime_to_timeval(entskb->tstamp);
444 ts.sec = cpu_to_be64(tv.tv_sec);
445 ts.usec = cpu_to_be64(tv.tv_usec);
446
447 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
448 goto nla_put_failure;
449 }
450
451 if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0)
452 goto nla_put_failure;
453
454 if (cap_len > 0 && nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
455 goto nla_put_failure;
456
457 if (data_len) {
458 struct nlattr *nla;
459
460 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
461 goto nla_put_failure;
462
463 nla = (struct nlattr *)skb_put(skb, sizeof(*nla));
464 nla->nla_type = NFQA_PAYLOAD;
465 nla->nla_len = nla_attr_size(data_len);
466
467 nfqnl_zcopy(skb, entskb, data_len, hlen);
468 }
469
470 nlh->nlmsg_len = skb->len;
471 return skb;
472
473 nla_put_failure:
474 kfree_skb(skb);
475 net_err_ratelimited("nf_queue: error creating packet message\n");
476 return NULL;
477 }
478
479 static int
480 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
481 {
482 struct sk_buff *nskb;
483 struct nfqnl_instance *queue;
484 int err = -ENOBUFS;
485 __be32 *packet_id_ptr;
486 int failopen = 0;
487 struct net *net = dev_net(entry->indev ?
488 entry->indev : entry->outdev);
489 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
490
491 /* rcu_read_lock()ed by nf_hook_slow() */
492 queue = instance_lookup(q, queuenum);
493 if (!queue) {
494 err = -ESRCH;
495 goto err_out;
496 }
497
498 if (queue->copy_mode == NFQNL_COPY_NONE) {
499 err = -EINVAL;
500 goto err_out;
501 }
502
503 nskb = nfqnl_build_packet_message(queue, entry, &packet_id_ptr);
504 if (nskb == NULL) {
505 err = -ENOMEM;
506 goto err_out;
507 }
508 spin_lock_bh(&queue->lock);
509
510 if (!queue->peer_portid) {
511 err = -EINVAL;
512 goto err_out_free_nskb;
513 }
514 if (queue->queue_total >= queue->queue_maxlen) {
515 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
516 failopen = 1;
517 err = 0;
518 } else {
519 queue->queue_dropped++;
520 net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
521 queue->queue_total);
522 }
523 goto err_out_free_nskb;
524 }
525 entry->id = ++queue->id_sequence;
526 *packet_id_ptr = htonl(entry->id);
527
528 /* nfnetlink_unicast will either free the nskb or add it to a socket */
529 err = nfnetlink_unicast(nskb, net, queue->peer_portid, MSG_DONTWAIT);
530 if (err < 0) {
531 queue->queue_user_dropped++;
532 goto err_out_unlock;
533 }
534
535 __enqueue_entry(queue, entry);
536
537 spin_unlock_bh(&queue->lock);
538 return 0;
539
540 err_out_free_nskb:
541 kfree_skb(nskb);
542 err_out_unlock:
543 spin_unlock_bh(&queue->lock);
544 if (failopen)
545 nf_reinject(entry, NF_ACCEPT);
546 err_out:
547 return err;
548 }
549
550 static int
551 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
552 {
553 struct sk_buff *nskb;
554
555 if (diff < 0) {
556 if (pskb_trim(e->skb, data_len))
557 return -ENOMEM;
558 } else if (diff > 0) {
559 if (data_len > 0xFFFF)
560 return -EINVAL;
561 if (diff > skb_tailroom(e->skb)) {
562 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
563 diff, GFP_ATOMIC);
564 if (!nskb) {
565 printk(KERN_WARNING "nf_queue: OOM "
566 "in mangle, dropping packet\n");
567 return -ENOMEM;
568 }
569 kfree_skb(e->skb);
570 e->skb = nskb;
571 }
572 skb_put(e->skb, diff);
573 }
574 if (!skb_make_writable(e->skb, data_len))
575 return -ENOMEM;
576 skb_copy_to_linear_data(e->skb, data, data_len);
577 e->skb->ip_summed = CHECKSUM_NONE;
578 return 0;
579 }
580
581 static int
582 nfqnl_set_mode(struct nfqnl_instance *queue,
583 unsigned char mode, unsigned int range)
584 {
585 int status = 0;
586
587 spin_lock_bh(&queue->lock);
588 switch (mode) {
589 case NFQNL_COPY_NONE:
590 case NFQNL_COPY_META:
591 queue->copy_mode = mode;
592 queue->copy_range = 0;
593 break;
594
595 case NFQNL_COPY_PACKET:
596 queue->copy_mode = mode;
597 /* We're using struct nlattr which has 16bit nla_len. Note that
598 * nla_len includes the header length. Thus, the maximum packet
599 * length that we support is 65531 bytes. We send truncated
600 * packets if the specified length is larger than that.
601 */
602 if (range > 0xffff - NLA_HDRLEN)
603 queue->copy_range = 0xffff - NLA_HDRLEN;
604 else
605 queue->copy_range = range;
606 break;
607
608 default:
609 status = -EINVAL;
610
611 }
612 spin_unlock_bh(&queue->lock);
613
614 return status;
615 }
616
617 static int
618 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
619 {
620 if (entry->indev)
621 if (entry->indev->ifindex == ifindex)
622 return 1;
623 if (entry->outdev)
624 if (entry->outdev->ifindex == ifindex)
625 return 1;
626 #ifdef CONFIG_BRIDGE_NETFILTER
627 if (entry->skb->nf_bridge) {
628 if (entry->skb->nf_bridge->physindev &&
629 entry->skb->nf_bridge->physindev->ifindex == ifindex)
630 return 1;
631 if (entry->skb->nf_bridge->physoutdev &&
632 entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
633 return 1;
634 }
635 #endif
636 return 0;
637 }
638
639 /* drop all packets with either indev or outdev == ifindex from all queue
640 * instances */
641 static void
642 nfqnl_dev_drop(struct net *net, int ifindex)
643 {
644 int i;
645 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
646
647 rcu_read_lock();
648
649 for (i = 0; i < INSTANCE_BUCKETS; i++) {
650 struct nfqnl_instance *inst;
651 struct hlist_head *head = &q->instance_table[i];
652
653 hlist_for_each_entry_rcu(inst, head, hlist)
654 nfqnl_flush(inst, dev_cmp, ifindex);
655 }
656
657 rcu_read_unlock();
658 }
659
660 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
661
662 static int
663 nfqnl_rcv_dev_event(struct notifier_block *this,
664 unsigned long event, void *ptr)
665 {
666 struct net_device *dev = ptr;
667
668 /* Drop any packets associated with the downed device */
669 if (event == NETDEV_DOWN)
670 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
671 return NOTIFY_DONE;
672 }
673
674 static struct notifier_block nfqnl_dev_notifier = {
675 .notifier_call = nfqnl_rcv_dev_event,
676 };
677
678 static int
679 nfqnl_rcv_nl_event(struct notifier_block *this,
680 unsigned long event, void *ptr)
681 {
682 struct netlink_notify *n = ptr;
683 struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
684
685 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
686 int i;
687
688 /* destroy all instances for this portid */
689 spin_lock(&q->instances_lock);
690 for (i = 0; i < INSTANCE_BUCKETS; i++) {
691 struct hlist_node *t2;
692 struct nfqnl_instance *inst;
693 struct hlist_head *head = &q->instance_table[i];
694
695 hlist_for_each_entry_safe(inst, t2, head, hlist) {
696 if (n->portid == inst->peer_portid)
697 __instance_destroy(inst);
698 }
699 }
700 spin_unlock(&q->instances_lock);
701 }
702 return NOTIFY_DONE;
703 }
704
705 static struct notifier_block nfqnl_rtnl_notifier = {
706 .notifier_call = nfqnl_rcv_nl_event,
707 };
708
709 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
710 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
711 [NFQA_MARK] = { .type = NLA_U32 },
712 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC },
713 [NFQA_CT] = { .type = NLA_UNSPEC },
714 };
715
716 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
717 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
718 [NFQA_MARK] = { .type = NLA_U32 },
719 };
720
721 static struct nfqnl_instance *
722 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, int nlportid)
723 {
724 struct nfqnl_instance *queue;
725
726 queue = instance_lookup(q, queue_num);
727 if (!queue)
728 return ERR_PTR(-ENODEV);
729
730 if (queue->peer_portid != nlportid)
731 return ERR_PTR(-EPERM);
732
733 return queue;
734 }
735
736 static struct nfqnl_msg_verdict_hdr*
737 verdicthdr_get(const struct nlattr * const nfqa[])
738 {
739 struct nfqnl_msg_verdict_hdr *vhdr;
740 unsigned int verdict;
741
742 if (!nfqa[NFQA_VERDICT_HDR])
743 return NULL;
744
745 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
746 verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
747 if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
748 return NULL;
749 return vhdr;
750 }
751
752 static int nfq_id_after(unsigned int id, unsigned int max)
753 {
754 return (int)(id - max) > 0;
755 }
756
757 static int
758 nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb,
759 const struct nlmsghdr *nlh,
760 const struct nlattr * const nfqa[])
761 {
762 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
763 struct nf_queue_entry *entry, *tmp;
764 unsigned int verdict, maxid;
765 struct nfqnl_msg_verdict_hdr *vhdr;
766 struct nfqnl_instance *queue;
767 LIST_HEAD(batch_list);
768 u16 queue_num = ntohs(nfmsg->res_id);
769
770 struct net *net = sock_net(ctnl);
771 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
772
773 queue = verdict_instance_lookup(q, queue_num,
774 NETLINK_CB(skb).portid);
775 if (IS_ERR(queue))
776 return PTR_ERR(queue);
777
778 vhdr = verdicthdr_get(nfqa);
779 if (!vhdr)
780 return -EINVAL;
781
782 verdict = ntohl(vhdr->verdict);
783 maxid = ntohl(vhdr->id);
784
785 spin_lock_bh(&queue->lock);
786
787 list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
788 if (nfq_id_after(entry->id, maxid))
789 break;
790 __dequeue_entry(queue, entry);
791 list_add_tail(&entry->list, &batch_list);
792 }
793
794 spin_unlock_bh(&queue->lock);
795
796 if (list_empty(&batch_list))
797 return -ENOENT;
798
799 list_for_each_entry_safe(entry, tmp, &batch_list, list) {
800 if (nfqa[NFQA_MARK])
801 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
802 nf_reinject(entry, verdict);
803 }
804 return 0;
805 }
806
807 static int
808 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
809 const struct nlmsghdr *nlh,
810 const struct nlattr * const nfqa[])
811 {
812 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
813 u_int16_t queue_num = ntohs(nfmsg->res_id);
814
815 struct nfqnl_msg_verdict_hdr *vhdr;
816 struct nfqnl_instance *queue;
817 unsigned int verdict;
818 struct nf_queue_entry *entry;
819 enum ip_conntrack_info uninitialized_var(ctinfo);
820 struct nf_conn *ct = NULL;
821
822 struct net *net = sock_net(ctnl);
823 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
824
825 queue = instance_lookup(q, queue_num);
826 if (!queue)
827 queue = verdict_instance_lookup(q, queue_num,
828 NETLINK_CB(skb).portid);
829 if (IS_ERR(queue))
830 return PTR_ERR(queue);
831
832 vhdr = verdicthdr_get(nfqa);
833 if (!vhdr)
834 return -EINVAL;
835
836 verdict = ntohl(vhdr->verdict);
837
838 entry = find_dequeue_entry(queue, ntohl(vhdr->id));
839 if (entry == NULL)
840 return -ENOENT;
841
842 rcu_read_lock();
843 if (nfqa[NFQA_CT] && (queue->flags & NFQA_CFG_F_CONNTRACK))
844 ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo);
845
846 if (nfqa[NFQA_PAYLOAD]) {
847 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
848 int diff = payload_len - entry->skb->len;
849
850 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
851 payload_len, entry, diff) < 0)
852 verdict = NF_DROP;
853
854 if (ct)
855 nfqnl_ct_seq_adjust(skb, ct, ctinfo, diff);
856 }
857 rcu_read_unlock();
858
859 if (nfqa[NFQA_MARK])
860 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
861
862 nf_reinject(entry, verdict);
863 return 0;
864 }
865
866 static int
867 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
868 const struct nlmsghdr *nlh,
869 const struct nlattr * const nfqa[])
870 {
871 return -ENOTSUPP;
872 }
873
874 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
875 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
876 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
877 };
878
879 static const struct nf_queue_handler nfqh = {
880 .outfn = &nfqnl_enqueue_packet,
881 };
882
883 static int
884 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
885 const struct nlmsghdr *nlh,
886 const struct nlattr * const nfqa[])
887 {
888 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
889 u_int16_t queue_num = ntohs(nfmsg->res_id);
890 struct nfqnl_instance *queue;
891 struct nfqnl_msg_config_cmd *cmd = NULL;
892 struct net *net = sock_net(ctnl);
893 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
894 int ret = 0;
895
896 if (nfqa[NFQA_CFG_CMD]) {
897 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
898
899 /* Obsolete commands without queue context */
900 switch (cmd->command) {
901 case NFQNL_CFG_CMD_PF_BIND: return 0;
902 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
903 }
904 }
905
906 rcu_read_lock();
907 queue = instance_lookup(q, queue_num);
908 if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
909 ret = -EPERM;
910 goto err_out_unlock;
911 }
912
913 if (cmd != NULL) {
914 switch (cmd->command) {
915 case NFQNL_CFG_CMD_BIND:
916 if (queue) {
917 ret = -EBUSY;
918 goto err_out_unlock;
919 }
920 queue = instance_create(q, queue_num,
921 NETLINK_CB(skb).portid);
922 if (IS_ERR(queue)) {
923 ret = PTR_ERR(queue);
924 goto err_out_unlock;
925 }
926 break;
927 case NFQNL_CFG_CMD_UNBIND:
928 if (!queue) {
929 ret = -ENODEV;
930 goto err_out_unlock;
931 }
932 instance_destroy(q, queue);
933 break;
934 case NFQNL_CFG_CMD_PF_BIND:
935 case NFQNL_CFG_CMD_PF_UNBIND:
936 break;
937 default:
938 ret = -ENOTSUPP;
939 break;
940 }
941 }
942
943 if (nfqa[NFQA_CFG_PARAMS]) {
944 struct nfqnl_msg_config_params *params;
945
946 if (!queue) {
947 ret = -ENODEV;
948 goto err_out_unlock;
949 }
950 params = nla_data(nfqa[NFQA_CFG_PARAMS]);
951 nfqnl_set_mode(queue, params->copy_mode,
952 ntohl(params->copy_range));
953 }
954
955 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
956 __be32 *queue_maxlen;
957
958 if (!queue) {
959 ret = -ENODEV;
960 goto err_out_unlock;
961 }
962 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
963 spin_lock_bh(&queue->lock);
964 queue->queue_maxlen = ntohl(*queue_maxlen);
965 spin_unlock_bh(&queue->lock);
966 }
967
968 if (nfqa[NFQA_CFG_FLAGS]) {
969 __u32 flags, mask;
970
971 if (!queue) {
972 ret = -ENODEV;
973 goto err_out_unlock;
974 }
975
976 if (!nfqa[NFQA_CFG_MASK]) {
977 /* A mask is needed to specify which flags are being
978 * changed.
979 */
980 ret = -EINVAL;
981 goto err_out_unlock;
982 }
983
984 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
985 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
986
987 if (flags >= NFQA_CFG_F_MAX) {
988 ret = -EOPNOTSUPP;
989 goto err_out_unlock;
990 }
991
992 spin_lock_bh(&queue->lock);
993 queue->flags &= ~mask;
994 queue->flags |= flags & mask;
995 spin_unlock_bh(&queue->lock);
996 }
997
998 err_out_unlock:
999 rcu_read_unlock();
1000 return ret;
1001 }
1002
1003 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1004 [NFQNL_MSG_PACKET] = { .call_rcu = nfqnl_recv_unsupp,
1005 .attr_count = NFQA_MAX, },
1006 [NFQNL_MSG_VERDICT] = { .call_rcu = nfqnl_recv_verdict,
1007 .attr_count = NFQA_MAX,
1008 .policy = nfqa_verdict_policy },
1009 [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config,
1010 .attr_count = NFQA_CFG_MAX,
1011 .policy = nfqa_cfg_policy },
1012 [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
1013 .attr_count = NFQA_MAX,
1014 .policy = nfqa_verdict_batch_policy },
1015 };
1016
1017 static const struct nfnetlink_subsystem nfqnl_subsys = {
1018 .name = "nf_queue",
1019 .subsys_id = NFNL_SUBSYS_QUEUE,
1020 .cb_count = NFQNL_MSG_MAX,
1021 .cb = nfqnl_cb,
1022 };
1023
1024 #ifdef CONFIG_PROC_FS
1025 struct iter_state {
1026 struct seq_net_private p;
1027 unsigned int bucket;
1028 };
1029
1030 static struct hlist_node *get_first(struct seq_file *seq)
1031 {
1032 struct iter_state *st = seq->private;
1033 struct net *net;
1034 struct nfnl_queue_net *q;
1035
1036 if (!st)
1037 return NULL;
1038
1039 net = seq_file_net(seq);
1040 q = nfnl_queue_pernet(net);
1041 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1042 if (!hlist_empty(&q->instance_table[st->bucket]))
1043 return q->instance_table[st->bucket].first;
1044 }
1045 return NULL;
1046 }
1047
1048 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1049 {
1050 struct iter_state *st = seq->private;
1051 struct net *net = seq_file_net(seq);
1052
1053 h = h->next;
1054 while (!h) {
1055 struct nfnl_queue_net *q;
1056
1057 if (++st->bucket >= INSTANCE_BUCKETS)
1058 return NULL;
1059
1060 q = nfnl_queue_pernet(net);
1061 h = q->instance_table[st->bucket].first;
1062 }
1063 return h;
1064 }
1065
1066 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1067 {
1068 struct hlist_node *head;
1069 head = get_first(seq);
1070
1071 if (head)
1072 while (pos && (head = get_next(seq, head)))
1073 pos--;
1074 return pos ? NULL : head;
1075 }
1076
1077 static void *seq_start(struct seq_file *s, loff_t *pos)
1078 __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1079 {
1080 spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1081 return get_idx(s, *pos);
1082 }
1083
1084 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1085 {
1086 (*pos)++;
1087 return get_next(s, v);
1088 }
1089
1090 static void seq_stop(struct seq_file *s, void *v)
1091 __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1092 {
1093 spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1094 }
1095
1096 static int seq_show(struct seq_file *s, void *v)
1097 {
1098 const struct nfqnl_instance *inst = v;
1099
1100 return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1101 inst->queue_num,
1102 inst->peer_portid, inst->queue_total,
1103 inst->copy_mode, inst->copy_range,
1104 inst->queue_dropped, inst->queue_user_dropped,
1105 inst->id_sequence, 1);
1106 }
1107
1108 static const struct seq_operations nfqnl_seq_ops = {
1109 .start = seq_start,
1110 .next = seq_next,
1111 .stop = seq_stop,
1112 .show = seq_show,
1113 };
1114
1115 static int nfqnl_open(struct inode *inode, struct file *file)
1116 {
1117 return seq_open_net(inode, file, &nfqnl_seq_ops,
1118 sizeof(struct iter_state));
1119 }
1120
1121 static const struct file_operations nfqnl_file_ops = {
1122 .owner = THIS_MODULE,
1123 .open = nfqnl_open,
1124 .read = seq_read,
1125 .llseek = seq_lseek,
1126 .release = seq_release_net,
1127 };
1128
1129 #endif /* PROC_FS */
1130
1131 static int __net_init nfnl_queue_net_init(struct net *net)
1132 {
1133 unsigned int i;
1134 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1135
1136 for (i = 0; i < INSTANCE_BUCKETS; i++)
1137 INIT_HLIST_HEAD(&q->instance_table[i]);
1138
1139 spin_lock_init(&q->instances_lock);
1140
1141 #ifdef CONFIG_PROC_FS
1142 if (!proc_create("nfnetlink_queue", 0440,
1143 net->nf.proc_netfilter, &nfqnl_file_ops))
1144 return -ENOMEM;
1145 #endif
1146 return 0;
1147 }
1148
1149 static void __net_exit nfnl_queue_net_exit(struct net *net)
1150 {
1151 remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1152 }
1153
1154 static struct pernet_operations nfnl_queue_net_ops = {
1155 .init = nfnl_queue_net_init,
1156 .exit = nfnl_queue_net_exit,
1157 .id = &nfnl_queue_net_id,
1158 .size = sizeof(struct nfnl_queue_net),
1159 };
1160
1161 static int __init nfnetlink_queue_init(void)
1162 {
1163 int status = -ENOMEM;
1164
1165 netlink_register_notifier(&nfqnl_rtnl_notifier);
1166 status = nfnetlink_subsys_register(&nfqnl_subsys);
1167 if (status < 0) {
1168 pr_err("nf_queue: failed to create netlink socket\n");
1169 goto cleanup_netlink_notifier;
1170 }
1171
1172 status = register_pernet_subsys(&nfnl_queue_net_ops);
1173 if (status < 0) {
1174 pr_err("nf_queue: failed to register pernet ops\n");
1175 goto cleanup_subsys;
1176 }
1177 register_netdevice_notifier(&nfqnl_dev_notifier);
1178 nf_register_queue_handler(&nfqh);
1179 return status;
1180
1181 cleanup_subsys:
1182 nfnetlink_subsys_unregister(&nfqnl_subsys);
1183 cleanup_netlink_notifier:
1184 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1185 return status;
1186 }
1187
1188 static void __exit nfnetlink_queue_fini(void)
1189 {
1190 nf_unregister_queue_handler();
1191 unregister_netdevice_notifier(&nfqnl_dev_notifier);
1192 unregister_pernet_subsys(&nfnl_queue_net_ops);
1193 nfnetlink_subsys_unregister(&nfqnl_subsys);
1194 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1195
1196 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1197 }
1198
1199 MODULE_DESCRIPTION("netfilter packet queue handler");
1200 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1201 MODULE_LICENSE("GPL");
1202 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1203
1204 module_init(nfnetlink_queue_init);
1205 module_exit(nfnetlink_queue_fini);
Linux kernel - Deliverables
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