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netfilter: move skb_gso_segment into nfnetlink_queue module
[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 net *net, struct nfqnl_instance *queue,
481 struct nf_queue_entry *entry)
482 {
483 struct sk_buff *nskb;
484 int err = -ENOBUFS;
485 __be32 *packet_id_ptr;
486 int failopen = 0;
487
488 nskb = nfqnl_build_packet_message(queue, entry, &packet_id_ptr);
489 if (nskb == NULL) {
490 err = -ENOMEM;
491 goto err_out;
492 }
493 spin_lock_bh(&queue->lock);
494
495 if (!queue->peer_portid) {
496 err = -EINVAL;
497 goto err_out_free_nskb;
498 }
499 if (queue->queue_total >= queue->queue_maxlen) {
500 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
501 failopen = 1;
502 err = 0;
503 } else {
504 queue->queue_dropped++;
505 net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
506 queue->queue_total);
507 }
508 goto err_out_free_nskb;
509 }
510 entry->id = ++queue->id_sequence;
511 *packet_id_ptr = htonl(entry->id);
512
513 /* nfnetlink_unicast will either free the nskb or add it to a socket */
514 err = nfnetlink_unicast(nskb, net, queue->peer_portid, MSG_DONTWAIT);
515 if (err < 0) {
516 queue->queue_user_dropped++;
517 goto err_out_unlock;
518 }
519
520 __enqueue_entry(queue, entry);
521
522 spin_unlock_bh(&queue->lock);
523 return 0;
524
525 err_out_free_nskb:
526 kfree_skb(nskb);
527 err_out_unlock:
528 spin_unlock_bh(&queue->lock);
529 if (failopen)
530 nf_reinject(entry, NF_ACCEPT);
531 err_out:
532 return err;
533 }
534
535 static struct nf_queue_entry *
536 nf_queue_entry_dup(struct nf_queue_entry *e)
537 {
538 struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
539 if (entry) {
540 if (nf_queue_entry_get_refs(entry))
541 return entry;
542 kfree(entry);
543 }
544 return NULL;
545 }
546
547 #ifdef CONFIG_BRIDGE_NETFILTER
548 /* When called from bridge netfilter, skb->data must point to MAC header
549 * before calling skb_gso_segment(). Else, original MAC header is lost
550 * and segmented skbs will be sent to wrong destination.
551 */
552 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
553 {
554 if (skb->nf_bridge)
555 __skb_push(skb, skb->network_header - skb->mac_header);
556 }
557
558 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
559 {
560 if (skb->nf_bridge)
561 __skb_pull(skb, skb->network_header - skb->mac_header);
562 }
563 #else
564 #define nf_bridge_adjust_skb_data(s) do {} while (0)
565 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
566 #endif
567
568 static void free_entry(struct nf_queue_entry *entry)
569 {
570 nf_queue_entry_release_refs(entry);
571 kfree(entry);
572 }
573
574 static int
575 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
576 struct sk_buff *skb, struct nf_queue_entry *entry)
577 {
578 int ret = -ENOMEM;
579 struct nf_queue_entry *entry_seg;
580
581 nf_bridge_adjust_segmented_data(skb);
582
583 if (skb->next == NULL) { /* last packet, no need to copy entry */
584 struct sk_buff *gso_skb = entry->skb;
585 entry->skb = skb;
586 ret = __nfqnl_enqueue_packet(net, queue, entry);
587 if (ret)
588 entry->skb = gso_skb;
589 return ret;
590 }
591
592 skb->next = NULL;
593
594 entry_seg = nf_queue_entry_dup(entry);
595 if (entry_seg) {
596 entry_seg->skb = skb;
597 ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
598 if (ret)
599 free_entry(entry_seg);
600 }
601 return ret;
602 }
603
604 static int
605 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
606 {
607 unsigned int queued;
608 struct nfqnl_instance *queue;
609 struct sk_buff *skb, *segs;
610 int err = -ENOBUFS;
611 struct net *net = dev_net(entry->indev ?
612 entry->indev : entry->outdev);
613 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
614
615 /* rcu_read_lock()ed by nf_hook_slow() */
616 queue = instance_lookup(q, queuenum);
617 if (!queue)
618 return -ESRCH;
619
620 if (queue->copy_mode == NFQNL_COPY_NONE)
621 return -EINVAL;
622
623 if (!skb_is_gso(entry->skb))
624 return __nfqnl_enqueue_packet(net, queue, entry);
625
626 skb = entry->skb;
627
628 switch (entry->pf) {
629 case NFPROTO_IPV4:
630 skb->protocol = htons(ETH_P_IP);
631 break;
632 case NFPROTO_IPV6:
633 skb->protocol = htons(ETH_P_IPV6);
634 break;
635 }
636
637 nf_bridge_adjust_skb_data(skb);
638 segs = skb_gso_segment(skb, 0);
639 /* Does not use PTR_ERR to limit the number of error codes that can be
640 * returned by nf_queue. For instance, callers rely on -ECANCELED to
641 * mean 'ignore this hook'.
642 */
643 if (IS_ERR(segs))
644 goto out_err;
645 queued = 0;
646 err = 0;
647 do {
648 struct sk_buff *nskb = segs->next;
649 if (err == 0)
650 err = __nfqnl_enqueue_packet_gso(net, queue,
651 segs, entry);
652 if (err == 0)
653 queued++;
654 else
655 kfree_skb(segs);
656 segs = nskb;
657 } while (segs);
658
659 if (queued) {
660 if (err) /* some segments are already queued */
661 free_entry(entry);
662 kfree_skb(skb);
663 return 0;
664 }
665 out_err:
666 nf_bridge_adjust_segmented_data(skb);
667 return err;
668 }
669
670 static int
671 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
672 {
673 struct sk_buff *nskb;
674
675 if (diff < 0) {
676 if (pskb_trim(e->skb, data_len))
677 return -ENOMEM;
678 } else if (diff > 0) {
679 if (data_len > 0xFFFF)
680 return -EINVAL;
681 if (diff > skb_tailroom(e->skb)) {
682 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
683 diff, GFP_ATOMIC);
684 if (!nskb) {
685 printk(KERN_WARNING "nf_queue: OOM "
686 "in mangle, dropping packet\n");
687 return -ENOMEM;
688 }
689 kfree_skb(e->skb);
690 e->skb = nskb;
691 }
692 skb_put(e->skb, diff);
693 }
694 if (!skb_make_writable(e->skb, data_len))
695 return -ENOMEM;
696 skb_copy_to_linear_data(e->skb, data, data_len);
697 e->skb->ip_summed = CHECKSUM_NONE;
698 return 0;
699 }
700
701 static int
702 nfqnl_set_mode(struct nfqnl_instance *queue,
703 unsigned char mode, unsigned int range)
704 {
705 int status = 0;
706
707 spin_lock_bh(&queue->lock);
708 switch (mode) {
709 case NFQNL_COPY_NONE:
710 case NFQNL_COPY_META:
711 queue->copy_mode = mode;
712 queue->copy_range = 0;
713 break;
714
715 case NFQNL_COPY_PACKET:
716 queue->copy_mode = mode;
717 /* We're using struct nlattr which has 16bit nla_len. Note that
718 * nla_len includes the header length. Thus, the maximum packet
719 * length that we support is 65531 bytes. We send truncated
720 * packets if the specified length is larger than that.
721 */
722 if (range > 0xffff - NLA_HDRLEN)
723 queue->copy_range = 0xffff - NLA_HDRLEN;
724 else
725 queue->copy_range = range;
726 break;
727
728 default:
729 status = -EINVAL;
730
731 }
732 spin_unlock_bh(&queue->lock);
733
734 return status;
735 }
736
737 static int
738 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
739 {
740 if (entry->indev)
741 if (entry->indev->ifindex == ifindex)
742 return 1;
743 if (entry->outdev)
744 if (entry->outdev->ifindex == ifindex)
745 return 1;
746 #ifdef CONFIG_BRIDGE_NETFILTER
747 if (entry->skb->nf_bridge) {
748 if (entry->skb->nf_bridge->physindev &&
749 entry->skb->nf_bridge->physindev->ifindex == ifindex)
750 return 1;
751 if (entry->skb->nf_bridge->physoutdev &&
752 entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
753 return 1;
754 }
755 #endif
756 return 0;
757 }
758
759 /* drop all packets with either indev or outdev == ifindex from all queue
760 * instances */
761 static void
762 nfqnl_dev_drop(struct net *net, int ifindex)
763 {
764 int i;
765 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
766
767 rcu_read_lock();
768
769 for (i = 0; i < INSTANCE_BUCKETS; i++) {
770 struct nfqnl_instance *inst;
771 struct hlist_head *head = &q->instance_table[i];
772
773 hlist_for_each_entry_rcu(inst, head, hlist)
774 nfqnl_flush(inst, dev_cmp, ifindex);
775 }
776
777 rcu_read_unlock();
778 }
779
780 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
781
782 static int
783 nfqnl_rcv_dev_event(struct notifier_block *this,
784 unsigned long event, void *ptr)
785 {
786 struct net_device *dev = ptr;
787
788 /* Drop any packets associated with the downed device */
789 if (event == NETDEV_DOWN)
790 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
791 return NOTIFY_DONE;
792 }
793
794 static struct notifier_block nfqnl_dev_notifier = {
795 .notifier_call = nfqnl_rcv_dev_event,
796 };
797
798 static int
799 nfqnl_rcv_nl_event(struct notifier_block *this,
800 unsigned long event, void *ptr)
801 {
802 struct netlink_notify *n = ptr;
803 struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
804
805 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
806 int i;
807
808 /* destroy all instances for this portid */
809 spin_lock(&q->instances_lock);
810 for (i = 0; i < INSTANCE_BUCKETS; i++) {
811 struct hlist_node *t2;
812 struct nfqnl_instance *inst;
813 struct hlist_head *head = &q->instance_table[i];
814
815 hlist_for_each_entry_safe(inst, t2, head, hlist) {
816 if (n->portid == inst->peer_portid)
817 __instance_destroy(inst);
818 }
819 }
820 spin_unlock(&q->instances_lock);
821 }
822 return NOTIFY_DONE;
823 }
824
825 static struct notifier_block nfqnl_rtnl_notifier = {
826 .notifier_call = nfqnl_rcv_nl_event,
827 };
828
829 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
830 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
831 [NFQA_MARK] = { .type = NLA_U32 },
832 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC },
833 [NFQA_CT] = { .type = NLA_UNSPEC },
834 };
835
836 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
837 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
838 [NFQA_MARK] = { .type = NLA_U32 },
839 };
840
841 static struct nfqnl_instance *
842 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, int nlportid)
843 {
844 struct nfqnl_instance *queue;
845
846 queue = instance_lookup(q, queue_num);
847 if (!queue)
848 return ERR_PTR(-ENODEV);
849
850 if (queue->peer_portid != nlportid)
851 return ERR_PTR(-EPERM);
852
853 return queue;
854 }
855
856 static struct nfqnl_msg_verdict_hdr*
857 verdicthdr_get(const struct nlattr * const nfqa[])
858 {
859 struct nfqnl_msg_verdict_hdr *vhdr;
860 unsigned int verdict;
861
862 if (!nfqa[NFQA_VERDICT_HDR])
863 return NULL;
864
865 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
866 verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
867 if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
868 return NULL;
869 return vhdr;
870 }
871
872 static int nfq_id_after(unsigned int id, unsigned int max)
873 {
874 return (int)(id - max) > 0;
875 }
876
877 static int
878 nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb,
879 const struct nlmsghdr *nlh,
880 const struct nlattr * const nfqa[])
881 {
882 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
883 struct nf_queue_entry *entry, *tmp;
884 unsigned int verdict, maxid;
885 struct nfqnl_msg_verdict_hdr *vhdr;
886 struct nfqnl_instance *queue;
887 LIST_HEAD(batch_list);
888 u16 queue_num = ntohs(nfmsg->res_id);
889
890 struct net *net = sock_net(ctnl);
891 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
892
893 queue = verdict_instance_lookup(q, queue_num,
894 NETLINK_CB(skb).portid);
895 if (IS_ERR(queue))
896 return PTR_ERR(queue);
897
898 vhdr = verdicthdr_get(nfqa);
899 if (!vhdr)
900 return -EINVAL;
901
902 verdict = ntohl(vhdr->verdict);
903 maxid = ntohl(vhdr->id);
904
905 spin_lock_bh(&queue->lock);
906
907 list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
908 if (nfq_id_after(entry->id, maxid))
909 break;
910 __dequeue_entry(queue, entry);
911 list_add_tail(&entry->list, &batch_list);
912 }
913
914 spin_unlock_bh(&queue->lock);
915
916 if (list_empty(&batch_list))
917 return -ENOENT;
918
919 list_for_each_entry_safe(entry, tmp, &batch_list, list) {
920 if (nfqa[NFQA_MARK])
921 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
922 nf_reinject(entry, verdict);
923 }
924 return 0;
925 }
926
927 static int
928 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
929 const struct nlmsghdr *nlh,
930 const struct nlattr * const nfqa[])
931 {
932 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
933 u_int16_t queue_num = ntohs(nfmsg->res_id);
934
935 struct nfqnl_msg_verdict_hdr *vhdr;
936 struct nfqnl_instance *queue;
937 unsigned int verdict;
938 struct nf_queue_entry *entry;
939 enum ip_conntrack_info uninitialized_var(ctinfo);
940 struct nf_conn *ct = NULL;
941
942 struct net *net = sock_net(ctnl);
943 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
944
945 queue = instance_lookup(q, queue_num);
946 if (!queue)
947 queue = verdict_instance_lookup(q, queue_num,
948 NETLINK_CB(skb).portid);
949 if (IS_ERR(queue))
950 return PTR_ERR(queue);
951
952 vhdr = verdicthdr_get(nfqa);
953 if (!vhdr)
954 return -EINVAL;
955
956 verdict = ntohl(vhdr->verdict);
957
958 entry = find_dequeue_entry(queue, ntohl(vhdr->id));
959 if (entry == NULL)
960 return -ENOENT;
961
962 rcu_read_lock();
963 if (nfqa[NFQA_CT] && (queue->flags & NFQA_CFG_F_CONNTRACK))
964 ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo);
965
966 if (nfqa[NFQA_PAYLOAD]) {
967 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
968 int diff = payload_len - entry->skb->len;
969
970 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
971 payload_len, entry, diff) < 0)
972 verdict = NF_DROP;
973
974 if (ct)
975 nfqnl_ct_seq_adjust(skb, ct, ctinfo, diff);
976 }
977 rcu_read_unlock();
978
979 if (nfqa[NFQA_MARK])
980 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
981
982 nf_reinject(entry, verdict);
983 return 0;
984 }
985
986 static int
987 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
988 const struct nlmsghdr *nlh,
989 const struct nlattr * const nfqa[])
990 {
991 return -ENOTSUPP;
992 }
993
994 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
995 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
996 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
997 };
998
999 static const struct nf_queue_handler nfqh = {
1000 .outfn = &nfqnl_enqueue_packet,
1001 };
1002
1003 static int
1004 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
1005 const struct nlmsghdr *nlh,
1006 const struct nlattr * const nfqa[])
1007 {
1008 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1009 u_int16_t queue_num = ntohs(nfmsg->res_id);
1010 struct nfqnl_instance *queue;
1011 struct nfqnl_msg_config_cmd *cmd = NULL;
1012 struct net *net = sock_net(ctnl);
1013 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1014 int ret = 0;
1015
1016 if (nfqa[NFQA_CFG_CMD]) {
1017 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1018
1019 /* Obsolete commands without queue context */
1020 switch (cmd->command) {
1021 case NFQNL_CFG_CMD_PF_BIND: return 0;
1022 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1023 }
1024 }
1025
1026 rcu_read_lock();
1027 queue = instance_lookup(q, queue_num);
1028 if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1029 ret = -EPERM;
1030 goto err_out_unlock;
1031 }
1032
1033 if (cmd != NULL) {
1034 switch (cmd->command) {
1035 case NFQNL_CFG_CMD_BIND:
1036 if (queue) {
1037 ret = -EBUSY;
1038 goto err_out_unlock;
1039 }
1040 queue = instance_create(q, queue_num,
1041 NETLINK_CB(skb).portid);
1042 if (IS_ERR(queue)) {
1043 ret = PTR_ERR(queue);
1044 goto err_out_unlock;
1045 }
1046 break;
1047 case NFQNL_CFG_CMD_UNBIND:
1048 if (!queue) {
1049 ret = -ENODEV;
1050 goto err_out_unlock;
1051 }
1052 instance_destroy(q, queue);
1053 break;
1054 case NFQNL_CFG_CMD_PF_BIND:
1055 case NFQNL_CFG_CMD_PF_UNBIND:
1056 break;
1057 default:
1058 ret = -ENOTSUPP;
1059 break;
1060 }
1061 }
1062
1063 if (nfqa[NFQA_CFG_PARAMS]) {
1064 struct nfqnl_msg_config_params *params;
1065
1066 if (!queue) {
1067 ret = -ENODEV;
1068 goto err_out_unlock;
1069 }
1070 params = nla_data(nfqa[NFQA_CFG_PARAMS]);
1071 nfqnl_set_mode(queue, params->copy_mode,
1072 ntohl(params->copy_range));
1073 }
1074
1075 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1076 __be32 *queue_maxlen;
1077
1078 if (!queue) {
1079 ret = -ENODEV;
1080 goto err_out_unlock;
1081 }
1082 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1083 spin_lock_bh(&queue->lock);
1084 queue->queue_maxlen = ntohl(*queue_maxlen);
1085 spin_unlock_bh(&queue->lock);
1086 }
1087
1088 if (nfqa[NFQA_CFG_FLAGS]) {
1089 __u32 flags, mask;
1090
1091 if (!queue) {
1092 ret = -ENODEV;
1093 goto err_out_unlock;
1094 }
1095
1096 if (!nfqa[NFQA_CFG_MASK]) {
1097 /* A mask is needed to specify which flags are being
1098 * changed.
1099 */
1100 ret = -EINVAL;
1101 goto err_out_unlock;
1102 }
1103
1104 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1105 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1106
1107 if (flags >= NFQA_CFG_F_MAX) {
1108 ret = -EOPNOTSUPP;
1109 goto err_out_unlock;
1110 }
1111
1112 spin_lock_bh(&queue->lock);
1113 queue->flags &= ~mask;
1114 queue->flags |= flags & mask;
1115 spin_unlock_bh(&queue->lock);
1116 }
1117
1118 err_out_unlock:
1119 rcu_read_unlock();
1120 return ret;
1121 }
1122
1123 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1124 [NFQNL_MSG_PACKET] = { .call_rcu = nfqnl_recv_unsupp,
1125 .attr_count = NFQA_MAX, },
1126 [NFQNL_MSG_VERDICT] = { .call_rcu = nfqnl_recv_verdict,
1127 .attr_count = NFQA_MAX,
1128 .policy = nfqa_verdict_policy },
1129 [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config,
1130 .attr_count = NFQA_CFG_MAX,
1131 .policy = nfqa_cfg_policy },
1132 [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
1133 .attr_count = NFQA_MAX,
1134 .policy = nfqa_verdict_batch_policy },
1135 };
1136
1137 static const struct nfnetlink_subsystem nfqnl_subsys = {
1138 .name = "nf_queue",
1139 .subsys_id = NFNL_SUBSYS_QUEUE,
1140 .cb_count = NFQNL_MSG_MAX,
1141 .cb = nfqnl_cb,
1142 };
1143
1144 #ifdef CONFIG_PROC_FS
1145 struct iter_state {
1146 struct seq_net_private p;
1147 unsigned int bucket;
1148 };
1149
1150 static struct hlist_node *get_first(struct seq_file *seq)
1151 {
1152 struct iter_state *st = seq->private;
1153 struct net *net;
1154 struct nfnl_queue_net *q;
1155
1156 if (!st)
1157 return NULL;
1158
1159 net = seq_file_net(seq);
1160 q = nfnl_queue_pernet(net);
1161 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1162 if (!hlist_empty(&q->instance_table[st->bucket]))
1163 return q->instance_table[st->bucket].first;
1164 }
1165 return NULL;
1166 }
1167
1168 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1169 {
1170 struct iter_state *st = seq->private;
1171 struct net *net = seq_file_net(seq);
1172
1173 h = h->next;
1174 while (!h) {
1175 struct nfnl_queue_net *q;
1176
1177 if (++st->bucket >= INSTANCE_BUCKETS)
1178 return NULL;
1179
1180 q = nfnl_queue_pernet(net);
1181 h = q->instance_table[st->bucket].first;
1182 }
1183 return h;
1184 }
1185
1186 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1187 {
1188 struct hlist_node *head;
1189 head = get_first(seq);
1190
1191 if (head)
1192 while (pos && (head = get_next(seq, head)))
1193 pos--;
1194 return pos ? NULL : head;
1195 }
1196
1197 static void *seq_start(struct seq_file *s, loff_t *pos)
1198 __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1199 {
1200 spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1201 return get_idx(s, *pos);
1202 }
1203
1204 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1205 {
1206 (*pos)++;
1207 return get_next(s, v);
1208 }
1209
1210 static void seq_stop(struct seq_file *s, void *v)
1211 __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1212 {
1213 spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1214 }
1215
1216 static int seq_show(struct seq_file *s, void *v)
1217 {
1218 const struct nfqnl_instance *inst = v;
1219
1220 return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
1221 inst->queue_num,
1222 inst->peer_portid, inst->queue_total,
1223 inst->copy_mode, inst->copy_range,
1224 inst->queue_dropped, inst->queue_user_dropped,
1225 inst->id_sequence, 1);
1226 }
1227
1228 static const struct seq_operations nfqnl_seq_ops = {
1229 .start = seq_start,
1230 .next = seq_next,
1231 .stop = seq_stop,
1232 .show = seq_show,
1233 };
1234
1235 static int nfqnl_open(struct inode *inode, struct file *file)
1236 {
1237 return seq_open_net(inode, file, &nfqnl_seq_ops,
1238 sizeof(struct iter_state));
1239 }
1240
1241 static const struct file_operations nfqnl_file_ops = {
1242 .owner = THIS_MODULE,
1243 .open = nfqnl_open,
1244 .read = seq_read,
1245 .llseek = seq_lseek,
1246 .release = seq_release_net,
1247 };
1248
1249 #endif /* PROC_FS */
1250
1251 static int __net_init nfnl_queue_net_init(struct net *net)
1252 {
1253 unsigned int i;
1254 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1255
1256 for (i = 0; i < INSTANCE_BUCKETS; i++)
1257 INIT_HLIST_HEAD(&q->instance_table[i]);
1258
1259 spin_lock_init(&q->instances_lock);
1260
1261 #ifdef CONFIG_PROC_FS
1262 if (!proc_create("nfnetlink_queue", 0440,
1263 net->nf.proc_netfilter, &nfqnl_file_ops))
1264 return -ENOMEM;
1265 #endif
1266 return 0;
1267 }
1268
1269 static void __net_exit nfnl_queue_net_exit(struct net *net)
1270 {
1271 remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1272 }
1273
1274 static struct pernet_operations nfnl_queue_net_ops = {
1275 .init = nfnl_queue_net_init,
1276 .exit = nfnl_queue_net_exit,
1277 .id = &nfnl_queue_net_id,
1278 .size = sizeof(struct nfnl_queue_net),
1279 };
1280
1281 static int __init nfnetlink_queue_init(void)
1282 {
1283 int status = -ENOMEM;
1284
1285 netlink_register_notifier(&nfqnl_rtnl_notifier);
1286 status = nfnetlink_subsys_register(&nfqnl_subsys);
1287 if (status < 0) {
1288 pr_err("nf_queue: failed to create netlink socket\n");
1289 goto cleanup_netlink_notifier;
1290 }
1291
1292 status = register_pernet_subsys(&nfnl_queue_net_ops);
1293 if (status < 0) {
1294 pr_err("nf_queue: failed to register pernet ops\n");
1295 goto cleanup_subsys;
1296 }
1297 register_netdevice_notifier(&nfqnl_dev_notifier);
1298 nf_register_queue_handler(&nfqh);
1299 return status;
1300
1301 cleanup_subsys:
1302 nfnetlink_subsys_unregister(&nfqnl_subsys);
1303 cleanup_netlink_notifier:
1304 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1305 return status;
1306 }
1307
1308 static void __exit nfnetlink_queue_fini(void)
1309 {
1310 nf_unregister_queue_handler();
1311 unregister_netdevice_notifier(&nfqnl_dev_notifier);
1312 unregister_pernet_subsys(&nfnl_queue_net_ops);
1313 nfnetlink_subsys_unregister(&nfqnl_subsys);
1314 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1315
1316 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1317 }
1318
1319 MODULE_DESCRIPTION("netfilter packet queue handler");
1320 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1321 MODULE_LICENSE("GPL");
1322 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1323
1324 module_init(nfnetlink_queue_init);
1325 module_exit(nfnetlink_queue_fini);
Linux kernel - Deliverables
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