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_bridge.h>
29 #include <linux/netfilter/nfnetlink.h>
30 #include <linux/netfilter/nfnetlink_queue.h>
31 #include <linux/netfilter/nf_conntrack_common.h>
32 #include <linux/list.h>
33 #include <net/sock.h>
34 #include <net/tcp_states.h>
35 #include <net/netfilter/nf_queue.h>
36 #include <net/netns/generic.h>
37
38 #include <linux/atomic.h>
39
40 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
41 #include "../bridge/br_private.h"
42 #endif
43
44 #define NFQNL_QMAX_DEFAULT 1024
45
46 /* We're using struct nlattr which has 16bit nla_len. Note that nla_len
47 * includes the header length. Thus, the maximum packet length that we
48 * support is 65531 bytes. We send truncated packets if the specified length
49 * is larger than that. Userspace can check for presence of NFQA_CAP_LEN
50 * attribute to detect truncation.
51 */
52 #define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN)
53
54 struct nfqnl_instance {
55 struct hlist_node hlist; /* global list of queues */
56 struct rcu_head rcu;
57
58 u32 peer_portid;
59 unsigned int queue_maxlen;
60 unsigned int copy_range;
61 unsigned int queue_dropped;
62 unsigned int queue_user_dropped;
63
64
65 u_int16_t queue_num; /* number of this queue */
66 u_int8_t copy_mode;
67 u_int32_t flags; /* Set using NFQA_CFG_FLAGS */
68 /*
69 * Following fields are dirtied for each queued packet,
70 * keep them in same cache line if possible.
71 */
72 spinlock_t lock;
73 unsigned int queue_total;
74 unsigned int id_sequence; /* 'sequence' of pkt ids */
75 struct list_head queue_list; /* packets in queue */
76 };
77
78 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
79
80 static int nfnl_queue_net_id __read_mostly;
81
82 #define INSTANCE_BUCKETS 16
83 struct nfnl_queue_net {
84 spinlock_t instances_lock;
85 struct hlist_head instance_table[INSTANCE_BUCKETS];
86 };
87
nfnl_queue_pernet(struct net * net)88 static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net)
89 {
90 return net_generic(net, nfnl_queue_net_id);
91 }
92
instance_hashfn(u_int16_t queue_num)93 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
94 {
95 return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS;
96 }
97
98 static struct nfqnl_instance *
instance_lookup(struct nfnl_queue_net * q,u_int16_t queue_num)99 instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num)
100 {
101 struct hlist_head *head;
102 struct nfqnl_instance *inst;
103
104 head = &q->instance_table[instance_hashfn(queue_num)];
105 hlist_for_each_entry_rcu(inst, head, hlist) {
106 if (inst->queue_num == queue_num)
107 return inst;
108 }
109 return NULL;
110 }
111
112 static struct nfqnl_instance *
instance_create(struct nfnl_queue_net * q,u_int16_t queue_num,u32 portid)113 instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid)
114 {
115 struct nfqnl_instance *inst;
116 unsigned int h;
117 int err;
118
119 spin_lock(&q->instances_lock);
120 if (instance_lookup(q, queue_num)) {
121 err = -EEXIST;
122 goto out_unlock;
123 }
124
125 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
126 if (!inst) {
127 err = -ENOMEM;
128 goto out_unlock;
129 }
130
131 inst->queue_num = queue_num;
132 inst->peer_portid = portid;
133 inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
134 inst->copy_range = NFQNL_MAX_COPY_RANGE;
135 inst->copy_mode = NFQNL_COPY_NONE;
136 spin_lock_init(&inst->lock);
137 INIT_LIST_HEAD(&inst->queue_list);
138
139 if (!try_module_get(THIS_MODULE)) {
140 err = -EAGAIN;
141 goto out_free;
142 }
143
144 h = instance_hashfn(queue_num);
145 hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]);
146
147 spin_unlock(&q->instances_lock);
148
149 return inst;
150
151 out_free:
152 kfree(inst);
153 out_unlock:
154 spin_unlock(&q->instances_lock);
155 return ERR_PTR(err);
156 }
157
158 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
159 unsigned long data);
160
161 static void
instance_destroy_rcu(struct rcu_head * head)162 instance_destroy_rcu(struct rcu_head *head)
163 {
164 struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
165 rcu);
166
167 nfqnl_flush(inst, NULL, 0);
168 kfree(inst);
169 module_put(THIS_MODULE);
170 }
171
172 static void
__instance_destroy(struct nfqnl_instance * inst)173 __instance_destroy(struct nfqnl_instance *inst)
174 {
175 hlist_del_rcu(&inst->hlist);
176 call_rcu(&inst->rcu, instance_destroy_rcu);
177 }
178
179 static void
instance_destroy(struct nfnl_queue_net * q,struct nfqnl_instance * inst)180 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
181 {
182 spin_lock(&q->instances_lock);
183 __instance_destroy(inst);
184 spin_unlock(&q->instances_lock);
185 }
186
187 static inline void
__enqueue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)188 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
189 {
190 list_add_tail(&entry->list, &queue->queue_list);
191 queue->queue_total++;
192 }
193
194 static void
__dequeue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)195 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
196 {
197 list_del(&entry->list);
198 queue->queue_total--;
199 }
200
201 static struct nf_queue_entry *
find_dequeue_entry(struct nfqnl_instance * queue,unsigned int id)202 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
203 {
204 struct nf_queue_entry *entry = NULL, *i;
205
206 spin_lock_bh(&queue->lock);
207
208 list_for_each_entry(i, &queue->queue_list, list) {
209 if (i->id == id) {
210 entry = i;
211 break;
212 }
213 }
214
215 if (entry)
216 __dequeue_entry(queue, entry);
217
218 spin_unlock_bh(&queue->lock);
219
220 return entry;
221 }
222
223 static void
nfqnl_flush(struct nfqnl_instance * queue,nfqnl_cmpfn cmpfn,unsigned long data)224 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
225 {
226 struct nf_queue_entry *entry, *next;
227
228 spin_lock_bh(&queue->lock);
229 list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
230 if (!cmpfn || cmpfn(entry, data)) {
231 list_del(&entry->list);
232 queue->queue_total--;
233 nf_reinject(entry, NF_DROP);
234 }
235 }
236 spin_unlock_bh(&queue->lock);
237 }
238
239 static int
nfqnl_put_packet_info(struct sk_buff * nlskb,struct sk_buff * packet,bool csum_verify)240 nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet,
241 bool csum_verify)
242 {
243 __u32 flags = 0;
244
245 if (packet->ip_summed == CHECKSUM_PARTIAL)
246 flags = NFQA_SKB_CSUMNOTREADY;
247 else if (csum_verify)
248 flags = NFQA_SKB_CSUM_NOTVERIFIED;
249
250 if (skb_is_gso(packet))
251 flags |= NFQA_SKB_GSO;
252
253 return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0;
254 }
255
nfqnl_put_sk_uidgid(struct sk_buff * skb,struct sock * sk)256 static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
257 {
258 const struct cred *cred;
259
260 if (!sk_fullsock(sk))
261 return 0;
262
263 read_lock_bh(&sk->sk_callback_lock);
264 if (sk->sk_socket && sk->sk_socket->file) {
265 cred = sk->sk_socket->file->f_cred;
266 if (nla_put_be32(skb, NFQA_UID,
267 htonl(from_kuid_munged(&init_user_ns, cred->fsuid))))
268 goto nla_put_failure;
269 if (nla_put_be32(skb, NFQA_GID,
270 htonl(from_kgid_munged(&init_user_ns, cred->fsgid))))
271 goto nla_put_failure;
272 }
273 read_unlock_bh(&sk->sk_callback_lock);
274 return 0;
275
276 nla_put_failure:
277 read_unlock_bh(&sk->sk_callback_lock);
278 return -1;
279 }
280
nfqnl_get_sk_secctx(struct sk_buff * skb,char ** secdata)281 static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
282 {
283 u32 seclen = 0;
284 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
285 if (!skb || !sk_fullsock(skb->sk))
286 return 0;
287
288 read_lock_bh(&skb->sk->sk_callback_lock);
289
290 if (skb->secmark)
291 security_secid_to_secctx(skb->secmark, secdata, &seclen);
292
293 read_unlock_bh(&skb->sk->sk_callback_lock);
294 #endif
295 return seclen;
296 }
297
nfqnl_get_bridge_size(struct nf_queue_entry * entry)298 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
299 {
300 struct sk_buff *entskb = entry->skb;
301 u32 nlalen = 0;
302
303 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
304 return 0;
305
306 if (skb_vlan_tag_present(entskb))
307 nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
308 nla_total_size(sizeof(__be16)));
309
310 if (entskb->network_header > entskb->mac_header)
311 nlalen += nla_total_size((entskb->network_header -
312 entskb->mac_header));
313
314 return nlalen;
315 }
316
nfqnl_put_bridge(struct nf_queue_entry * entry,struct sk_buff * skb)317 static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
318 {
319 struct sk_buff *entskb = entry->skb;
320
321 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
322 return 0;
323
324 if (skb_vlan_tag_present(entskb)) {
325 struct nlattr *nest;
326
327 nest = nla_nest_start(skb, NFQA_VLAN | NLA_F_NESTED);
328 if (!nest)
329 goto nla_put_failure;
330
331 if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
332 nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
333 goto nla_put_failure;
334
335 nla_nest_end(skb, nest);
336 }
337
338 if (entskb->mac_header < entskb->network_header) {
339 int len = (int)(entskb->network_header - entskb->mac_header);
340
341 if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb)))
342 goto nla_put_failure;
343 }
344
345 return 0;
346
347 nla_put_failure:
348 return -1;
349 }
350
351 static struct sk_buff *
nfqnl_build_packet_message(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry,__be32 ** packet_id_ptr)352 nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
353 struct nf_queue_entry *entry,
354 __be32 **packet_id_ptr)
355 {
356 size_t size;
357 size_t data_len = 0, cap_len = 0;
358 unsigned int hlen = 0;
359 struct sk_buff *skb;
360 struct nlattr *nla;
361 struct nfqnl_msg_packet_hdr *pmsg;
362 struct nlmsghdr *nlh;
363 struct nfgenmsg *nfmsg;
364 struct sk_buff *entskb = entry->skb;
365 struct net_device *indev;
366 struct net_device *outdev;
367 struct nf_conn *ct = NULL;
368 enum ip_conntrack_info uninitialized_var(ctinfo);
369 struct nfnl_ct_hook *nfnl_ct;
370 bool csum_verify;
371 char *secdata = NULL;
372 u32 seclen = 0;
373
374 size = nlmsg_total_size(sizeof(struct nfgenmsg))
375 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
376 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
377 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
378 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
379 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
380 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
381 #endif
382 + nla_total_size(sizeof(u_int32_t)) /* mark */
383 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
384 + nla_total_size(sizeof(u_int32_t)) /* skbinfo */
385 + nla_total_size(sizeof(u_int32_t)); /* cap_len */
386
387 if (entskb->tstamp.tv64)
388 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
389
390 size += nfqnl_get_bridge_size(entry);
391
392 if (entry->state.hook <= NF_INET_FORWARD ||
393 (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
394 csum_verify = !skb_csum_unnecessary(entskb);
395 else
396 csum_verify = false;
397
398 outdev = entry->state.out;
399
400 switch ((enum nfqnl_config_mode)ACCESS_ONCE(queue->copy_mode)) {
401 case NFQNL_COPY_META:
402 case NFQNL_COPY_NONE:
403 break;
404
405 case NFQNL_COPY_PACKET:
406 if (!(queue->flags & NFQA_CFG_F_GSO) &&
407 entskb->ip_summed == CHECKSUM_PARTIAL &&
408 skb_checksum_help(entskb))
409 return NULL;
410
411 data_len = ACCESS_ONCE(queue->copy_range);
412 if (data_len > entskb->len)
413 data_len = entskb->len;
414
415 hlen = skb_zerocopy_headlen(entskb);
416 hlen = min_t(unsigned int, hlen, data_len);
417 size += sizeof(struct nlattr) + hlen;
418 cap_len = entskb->len;
419 break;
420 }
421
422 nfnl_ct = rcu_dereference(nfnl_ct_hook);
423
424 if (queue->flags & NFQA_CFG_F_CONNTRACK) {
425 if (nfnl_ct != NULL) {
426 ct = nfnl_ct->get_ct(entskb, &ctinfo);
427 if (ct != NULL)
428 size += nfnl_ct->build_size(ct);
429 }
430 }
431
432 if (queue->flags & NFQA_CFG_F_UID_GID) {
433 size += (nla_total_size(sizeof(u_int32_t)) /* uid */
434 + nla_total_size(sizeof(u_int32_t))); /* gid */
435 }
436
437 if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
438 seclen = nfqnl_get_sk_secctx(entskb, &secdata);
439 if (seclen)
440 size += nla_total_size(seclen);
441 }
442
443 skb = alloc_skb(size, GFP_ATOMIC);
444 if (!skb) {
445 skb_tx_error(entskb);
446 goto nlmsg_failure;
447 }
448
449 nlh = nlmsg_put(skb, 0, 0,
450 NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
451 sizeof(struct nfgenmsg), 0);
452 if (!nlh) {
453 skb_tx_error(entskb);
454 kfree_skb(skb);
455 goto nlmsg_failure;
456 }
457 nfmsg = nlmsg_data(nlh);
458 nfmsg->nfgen_family = entry->state.pf;
459 nfmsg->version = NFNETLINK_V0;
460 nfmsg->res_id = htons(queue->queue_num);
461
462 nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
463 pmsg = nla_data(nla);
464 pmsg->hw_protocol = entskb->protocol;
465 pmsg->hook = entry->state.hook;
466 *packet_id_ptr = &pmsg->packet_id;
467
468 indev = entry->state.in;
469 if (indev) {
470 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
471 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
472 goto nla_put_failure;
473 #else
474 if (entry->state.pf == PF_BRIDGE) {
475 /* Case 1: indev is physical input device, we need to
476 * look for bridge group (when called from
477 * netfilter_bridge) */
478 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
479 htonl(indev->ifindex)) ||
480 /* this is the bridge group "brX" */
481 /* rcu_read_lock()ed by __nf_queue */
482 nla_put_be32(skb, NFQA_IFINDEX_INDEV,
483 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
484 goto nla_put_failure;
485 } else {
486 int physinif;
487
488 /* Case 2: indev is bridge group, we need to look for
489 * physical device (when called from ipv4) */
490 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
491 htonl(indev->ifindex)))
492 goto nla_put_failure;
493
494 physinif = nf_bridge_get_physinif(entskb);
495 if (physinif &&
496 nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
497 htonl(physinif)))
498 goto nla_put_failure;
499 }
500 #endif
501 }
502
503 if (outdev) {
504 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
505 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
506 goto nla_put_failure;
507 #else
508 if (entry->state.pf == PF_BRIDGE) {
509 /* Case 1: outdev is physical output device, we need to
510 * look for bridge group (when called from
511 * netfilter_bridge) */
512 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
513 htonl(outdev->ifindex)) ||
514 /* this is the bridge group "brX" */
515 /* rcu_read_lock()ed by __nf_queue */
516 nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
517 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
518 goto nla_put_failure;
519 } else {
520 int physoutif;
521
522 /* Case 2: outdev is bridge group, we need to look for
523 * physical output device (when called from ipv4) */
524 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
525 htonl(outdev->ifindex)))
526 goto nla_put_failure;
527
528 physoutif = nf_bridge_get_physoutif(entskb);
529 if (physoutif &&
530 nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
531 htonl(physoutif)))
532 goto nla_put_failure;
533 }
534 #endif
535 }
536
537 if (entskb->mark &&
538 nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
539 goto nla_put_failure;
540
541 if (indev && entskb->dev &&
542 entskb->mac_header != entskb->network_header) {
543 struct nfqnl_msg_packet_hw phw;
544 int len;
545
546 memset(&phw, 0, sizeof(phw));
547 len = dev_parse_header(entskb, phw.hw_addr);
548 if (len) {
549 phw.hw_addrlen = htons(len);
550 if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
551 goto nla_put_failure;
552 }
553 }
554
555 if (nfqnl_put_bridge(entry, skb) < 0)
556 goto nla_put_failure;
557
558 if (entskb->tstamp.tv64) {
559 struct nfqnl_msg_packet_timestamp ts;
560 struct timespec64 kts = ktime_to_timespec64(entskb->tstamp);
561
562 ts.sec = cpu_to_be64(kts.tv_sec);
563 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
564
565 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
566 goto nla_put_failure;
567 }
568
569 if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
570 nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
571 goto nla_put_failure;
572
573 if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
574 goto nla_put_failure;
575
576 if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
577 goto nla_put_failure;
578
579 if (cap_len > data_len &&
580 nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
581 goto nla_put_failure;
582
583 if (nfqnl_put_packet_info(skb, entskb, csum_verify))
584 goto nla_put_failure;
585
586 if (data_len) {
587 struct nlattr *nla;
588
589 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
590 goto nla_put_failure;
591
592 nla = (struct nlattr *)skb_put(skb, sizeof(*nla));
593 nla->nla_type = NFQA_PAYLOAD;
594 nla->nla_len = nla_attr_size(data_len);
595
596 if (skb_zerocopy(skb, entskb, data_len, hlen))
597 goto nla_put_failure;
598 }
599
600 nlh->nlmsg_len = skb->len;
601 if (seclen)
602 security_release_secctx(secdata, seclen);
603 return skb;
604
605 nla_put_failure:
606 skb_tx_error(entskb);
607 kfree_skb(skb);
608 net_err_ratelimited("nf_queue: error creating packet message\n");
609 nlmsg_failure:
610 if (seclen)
611 security_release_secctx(secdata, seclen);
612 return NULL;
613 }
614
615 static int
__nfqnl_enqueue_packet(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry)616 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
617 struct nf_queue_entry *entry)
618 {
619 struct sk_buff *nskb;
620 int err = -ENOBUFS;
621 __be32 *packet_id_ptr;
622 int failopen = 0;
623
624 nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
625 if (nskb == NULL) {
626 err = -ENOMEM;
627 goto err_out;
628 }
629 spin_lock_bh(&queue->lock);
630
631 if (queue->queue_total >= queue->queue_maxlen) {
632 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
633 failopen = 1;
634 err = 0;
635 } else {
636 queue->queue_dropped++;
637 net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
638 queue->queue_total);
639 }
640 goto err_out_free_nskb;
641 }
642 entry->id = ++queue->id_sequence;
643 *packet_id_ptr = htonl(entry->id);
644
645 /* nfnetlink_unicast will either free the nskb or add it to a socket */
646 err = nfnetlink_unicast(nskb, net, queue->peer_portid, MSG_DONTWAIT);
647 if (err < 0) {
648 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
649 failopen = 1;
650 err = 0;
651 } else {
652 queue->queue_user_dropped++;
653 }
654 goto err_out_unlock;
655 }
656
657 __enqueue_entry(queue, entry);
658
659 spin_unlock_bh(&queue->lock);
660 return 0;
661
662 err_out_free_nskb:
663 kfree_skb(nskb);
664 err_out_unlock:
665 spin_unlock_bh(&queue->lock);
666 if (failopen)
667 nf_reinject(entry, NF_ACCEPT);
668 err_out:
669 return err;
670 }
671
672 static struct nf_queue_entry *
nf_queue_entry_dup(struct nf_queue_entry * e)673 nf_queue_entry_dup(struct nf_queue_entry *e)
674 {
675 struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
676 if (entry)
677 nf_queue_entry_get_refs(entry);
678 return entry;
679 }
680
681 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
682 /* When called from bridge netfilter, skb->data must point to MAC header
683 * before calling skb_gso_segment(). Else, original MAC header is lost
684 * and segmented skbs will be sent to wrong destination.
685 */
nf_bridge_adjust_skb_data(struct sk_buff * skb)686 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
687 {
688 if (skb->nf_bridge)
689 __skb_push(skb, skb->network_header - skb->mac_header);
690 }
691
nf_bridge_adjust_segmented_data(struct sk_buff * skb)692 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
693 {
694 if (skb->nf_bridge)
695 __skb_pull(skb, skb->network_header - skb->mac_header);
696 }
697 #else
698 #define nf_bridge_adjust_skb_data(s) do {} while (0)
699 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
700 #endif
701
free_entry(struct nf_queue_entry * entry)702 static void free_entry(struct nf_queue_entry *entry)
703 {
704 nf_queue_entry_release_refs(entry);
705 kfree(entry);
706 }
707
708 static int
__nfqnl_enqueue_packet_gso(struct net * net,struct nfqnl_instance * queue,struct sk_buff * skb,struct nf_queue_entry * entry)709 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
710 struct sk_buff *skb, struct nf_queue_entry *entry)
711 {
712 int ret = -ENOMEM;
713 struct nf_queue_entry *entry_seg;
714
715 nf_bridge_adjust_segmented_data(skb);
716
717 if (skb->next == NULL) { /* last packet, no need to copy entry */
718 struct sk_buff *gso_skb = entry->skb;
719 entry->skb = skb;
720 ret = __nfqnl_enqueue_packet(net, queue, entry);
721 if (ret)
722 entry->skb = gso_skb;
723 return ret;
724 }
725
726 skb->next = NULL;
727
728 entry_seg = nf_queue_entry_dup(entry);
729 if (entry_seg) {
730 entry_seg->skb = skb;
731 ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
732 if (ret)
733 free_entry(entry_seg);
734 }
735 return ret;
736 }
737
738 static int
nfqnl_enqueue_packet(struct nf_queue_entry * entry,unsigned int queuenum)739 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
740 {
741 unsigned int queued;
742 struct nfqnl_instance *queue;
743 struct sk_buff *skb, *segs;
744 int err = -ENOBUFS;
745 struct net *net = entry->state.net;
746 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
747
748 /* rcu_read_lock()ed by nf_hook_thresh */
749 queue = instance_lookup(q, queuenum);
750 if (!queue)
751 return -ESRCH;
752
753 if (queue->copy_mode == NFQNL_COPY_NONE)
754 return -EINVAL;
755
756 skb = entry->skb;
757
758 switch (entry->state.pf) {
759 case NFPROTO_IPV4:
760 skb->protocol = htons(ETH_P_IP);
761 break;
762 case NFPROTO_IPV6:
763 skb->protocol = htons(ETH_P_IPV6);
764 break;
765 }
766
767 if ((queue->flags & NFQA_CFG_F_GSO) || !skb_is_gso(skb))
768 return __nfqnl_enqueue_packet(net, queue, entry);
769
770 nf_bridge_adjust_skb_data(skb);
771 segs = skb_gso_segment(skb, 0);
772 /* Does not use PTR_ERR to limit the number of error codes that can be
773 * returned by nf_queue. For instance, callers rely on -ESRCH to
774 * mean 'ignore this hook'.
775 */
776 if (IS_ERR_OR_NULL(segs))
777 goto out_err;
778 queued = 0;
779 err = 0;
780 do {
781 struct sk_buff *nskb = segs->next;
782 if (err == 0)
783 err = __nfqnl_enqueue_packet_gso(net, queue,
784 segs, entry);
785 if (err == 0)
786 queued++;
787 else
788 kfree_skb(segs);
789 segs = nskb;
790 } while (segs);
791
792 if (queued) {
793 if (err) /* some segments are already queued */
794 free_entry(entry);
795 kfree_skb(skb);
796 return 0;
797 }
798 out_err:
799 nf_bridge_adjust_segmented_data(skb);
800 return err;
801 }
802
803 static int
nfqnl_mangle(void * data,int data_len,struct nf_queue_entry * e,int diff)804 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
805 {
806 struct sk_buff *nskb;
807
808 if (diff < 0) {
809 if (pskb_trim(e->skb, data_len))
810 return -ENOMEM;
811 } else if (diff > 0) {
812 if (data_len > 0xFFFF)
813 return -EINVAL;
814 if (diff > skb_tailroom(e->skb)) {
815 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
816 diff, GFP_ATOMIC);
817 if (!nskb) {
818 printk(KERN_WARNING "nf_queue: OOM "
819 "in mangle, dropping packet\n");
820 return -ENOMEM;
821 }
822 kfree_skb(e->skb);
823 e->skb = nskb;
824 }
825 skb_put(e->skb, diff);
826 }
827 if (!skb_make_writable(e->skb, data_len))
828 return -ENOMEM;
829 skb_copy_to_linear_data(e->skb, data, data_len);
830 e->skb->ip_summed = CHECKSUM_NONE;
831 return 0;
832 }
833
834 static int
nfqnl_set_mode(struct nfqnl_instance * queue,unsigned char mode,unsigned int range)835 nfqnl_set_mode(struct nfqnl_instance *queue,
836 unsigned char mode, unsigned int range)
837 {
838 int status = 0;
839
840 spin_lock_bh(&queue->lock);
841 switch (mode) {
842 case NFQNL_COPY_NONE:
843 case NFQNL_COPY_META:
844 queue->copy_mode = mode;
845 queue->copy_range = 0;
846 break;
847
848 case NFQNL_COPY_PACKET:
849 queue->copy_mode = mode;
850 if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
851 queue->copy_range = NFQNL_MAX_COPY_RANGE;
852 else
853 queue->copy_range = range;
854 break;
855
856 default:
857 status = -EINVAL;
858
859 }
860 spin_unlock_bh(&queue->lock);
861
862 return status;
863 }
864
865 static int
dev_cmp(struct nf_queue_entry * entry,unsigned long ifindex)866 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
867 {
868 if (entry->state.in)
869 if (entry->state.in->ifindex == ifindex)
870 return 1;
871 if (entry->state.out)
872 if (entry->state.out->ifindex == ifindex)
873 return 1;
874 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
875 if (entry->skb->nf_bridge) {
876 int physinif, physoutif;
877
878 physinif = nf_bridge_get_physinif(entry->skb);
879 physoutif = nf_bridge_get_physoutif(entry->skb);
880
881 if (physinif == ifindex || physoutif == ifindex)
882 return 1;
883 }
884 #endif
885 return 0;
886 }
887
888 /* drop all packets with either indev or outdev == ifindex from all queue
889 * instances */
890 static void
nfqnl_dev_drop(struct net * net,int ifindex)891 nfqnl_dev_drop(struct net *net, int ifindex)
892 {
893 int i;
894 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
895
896 rcu_read_lock();
897
898 for (i = 0; i < INSTANCE_BUCKETS; i++) {
899 struct nfqnl_instance *inst;
900 struct hlist_head *head = &q->instance_table[i];
901
902 hlist_for_each_entry_rcu(inst, head, hlist)
903 nfqnl_flush(inst, dev_cmp, ifindex);
904 }
905
906 rcu_read_unlock();
907 }
908
909 static int
nfqnl_rcv_dev_event(struct notifier_block * this,unsigned long event,void * ptr)910 nfqnl_rcv_dev_event(struct notifier_block *this,
911 unsigned long event, void *ptr)
912 {
913 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
914
915 /* Drop any packets associated with the downed device */
916 if (event == NETDEV_DOWN)
917 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
918 return NOTIFY_DONE;
919 }
920
921 static struct notifier_block nfqnl_dev_notifier = {
922 .notifier_call = nfqnl_rcv_dev_event,
923 };
924
nf_hook_cmp(struct nf_queue_entry * entry,unsigned long entry_ptr)925 static int nf_hook_cmp(struct nf_queue_entry *entry, unsigned long entry_ptr)
926 {
927 return rcu_access_pointer(entry->state.hook_entries) ==
928 (struct nf_hook_entry *)entry_ptr;
929 }
930
nfqnl_nf_hook_drop(struct net * net,const struct nf_hook_entry * hook)931 static void nfqnl_nf_hook_drop(struct net *net,
932 const struct nf_hook_entry *hook)
933 {
934 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
935 int i;
936
937 rcu_read_lock();
938 for (i = 0; i < INSTANCE_BUCKETS; i++) {
939 struct nfqnl_instance *inst;
940 struct hlist_head *head = &q->instance_table[i];
941
942 hlist_for_each_entry_rcu(inst, head, hlist)
943 nfqnl_flush(inst, nf_hook_cmp, (unsigned long)hook);
944 }
945 rcu_read_unlock();
946 }
947
948 static int
nfqnl_rcv_nl_event(struct notifier_block * this,unsigned long event,void * ptr)949 nfqnl_rcv_nl_event(struct notifier_block *this,
950 unsigned long event, void *ptr)
951 {
952 struct netlink_notify *n = ptr;
953 struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
954
955 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
956 int i;
957
958 /* destroy all instances for this portid */
959 spin_lock(&q->instances_lock);
960 for (i = 0; i < INSTANCE_BUCKETS; i++) {
961 struct hlist_node *t2;
962 struct nfqnl_instance *inst;
963 struct hlist_head *head = &q->instance_table[i];
964
965 hlist_for_each_entry_safe(inst, t2, head, hlist) {
966 if (n->portid == inst->peer_portid)
967 __instance_destroy(inst);
968 }
969 }
970 spin_unlock(&q->instances_lock);
971 }
972 return NOTIFY_DONE;
973 }
974
975 static struct notifier_block nfqnl_rtnl_notifier = {
976 .notifier_call = nfqnl_rcv_nl_event,
977 };
978
979 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
980 [NFQA_VLAN_TCI] = { .type = NLA_U16},
981 [NFQA_VLAN_PROTO] = { .type = NLA_U16},
982 };
983
984 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
985 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
986 [NFQA_MARK] = { .type = NLA_U32 },
987 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC },
988 [NFQA_CT] = { .type = NLA_UNSPEC },
989 [NFQA_EXP] = { .type = NLA_UNSPEC },
990 [NFQA_VLAN] = { .type = NLA_NESTED },
991 };
992
993 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
994 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
995 [NFQA_MARK] = { .type = NLA_U32 },
996 };
997
998 static struct nfqnl_instance *
verdict_instance_lookup(struct nfnl_queue_net * q,u16 queue_num,u32 nlportid)999 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
1000 {
1001 struct nfqnl_instance *queue;
1002
1003 queue = instance_lookup(q, queue_num);
1004 if (!queue)
1005 return ERR_PTR(-ENODEV);
1006
1007 if (queue->peer_portid != nlportid)
1008 return ERR_PTR(-EPERM);
1009
1010 return queue;
1011 }
1012
1013 static struct nfqnl_msg_verdict_hdr*
verdicthdr_get(const struct nlattr * const nfqa[])1014 verdicthdr_get(const struct nlattr * const nfqa[])
1015 {
1016 struct nfqnl_msg_verdict_hdr *vhdr;
1017 unsigned int verdict;
1018
1019 if (!nfqa[NFQA_VERDICT_HDR])
1020 return NULL;
1021
1022 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
1023 verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
1024 if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
1025 return NULL;
1026 return vhdr;
1027 }
1028
nfq_id_after(unsigned int id,unsigned int max)1029 static int nfq_id_after(unsigned int id, unsigned int max)
1030 {
1031 return (int)(id - max) > 0;
1032 }
1033
nfqnl_recv_verdict_batch(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const nfqa[])1034 static int nfqnl_recv_verdict_batch(struct net *net, struct sock *ctnl,
1035 struct sk_buff *skb,
1036 const struct nlmsghdr *nlh,
1037 const struct nlattr * const nfqa[])
1038 {
1039 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1040 struct nf_queue_entry *entry, *tmp;
1041 unsigned int verdict, maxid;
1042 struct nfqnl_msg_verdict_hdr *vhdr;
1043 struct nfqnl_instance *queue;
1044 LIST_HEAD(batch_list);
1045 u16 queue_num = ntohs(nfmsg->res_id);
1046 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1047
1048 queue = verdict_instance_lookup(q, queue_num,
1049 NETLINK_CB(skb).portid);
1050 if (IS_ERR(queue))
1051 return PTR_ERR(queue);
1052
1053 vhdr = verdicthdr_get(nfqa);
1054 if (!vhdr)
1055 return -EINVAL;
1056
1057 verdict = ntohl(vhdr->verdict);
1058 maxid = ntohl(vhdr->id);
1059
1060 spin_lock_bh(&queue->lock);
1061
1062 list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
1063 if (nfq_id_after(entry->id, maxid))
1064 break;
1065 __dequeue_entry(queue, entry);
1066 list_add_tail(&entry->list, &batch_list);
1067 }
1068
1069 spin_unlock_bh(&queue->lock);
1070
1071 if (list_empty(&batch_list))
1072 return -ENOENT;
1073
1074 list_for_each_entry_safe(entry, tmp, &batch_list, list) {
1075 if (nfqa[NFQA_MARK])
1076 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1077 nf_reinject(entry, verdict);
1078 }
1079 return 0;
1080 }
1081
nfqnl_ct_parse(struct nfnl_ct_hook * nfnl_ct,const struct nlmsghdr * nlh,const struct nlattr * const nfqa[],struct nf_queue_entry * entry,enum ip_conntrack_info * ctinfo)1082 static struct nf_conn *nfqnl_ct_parse(struct nfnl_ct_hook *nfnl_ct,
1083 const struct nlmsghdr *nlh,
1084 const struct nlattr * const nfqa[],
1085 struct nf_queue_entry *entry,
1086 enum ip_conntrack_info *ctinfo)
1087 {
1088 struct nf_conn *ct;
1089
1090 ct = nfnl_ct->get_ct(entry->skb, ctinfo);
1091 if (ct == NULL)
1092 return NULL;
1093
1094 if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
1095 return NULL;
1096
1097 if (nfqa[NFQA_EXP])
1098 nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
1099 NETLINK_CB(entry->skb).portid,
1100 nlmsg_report(nlh));
1101 return ct;
1102 }
1103
nfqa_parse_bridge(struct nf_queue_entry * entry,const struct nlattr * const nfqa[])1104 static int nfqa_parse_bridge(struct nf_queue_entry *entry,
1105 const struct nlattr * const nfqa[])
1106 {
1107 if (nfqa[NFQA_VLAN]) {
1108 struct nlattr *tb[NFQA_VLAN_MAX + 1];
1109 int err;
1110
1111 err = nla_parse_nested(tb, NFQA_VLAN_MAX, nfqa[NFQA_VLAN],
1112 nfqa_vlan_policy);
1113 if (err < 0)
1114 return err;
1115
1116 if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
1117 return -EINVAL;
1118
1119 entry->skb->vlan_tci = ntohs(nla_get_be16(tb[NFQA_VLAN_TCI]));
1120 entry->skb->vlan_proto = nla_get_be16(tb[NFQA_VLAN_PROTO]);
1121 }
1122
1123 if (nfqa[NFQA_L2HDR]) {
1124 int mac_header_len = entry->skb->network_header -
1125 entry->skb->mac_header;
1126
1127 if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
1128 return -EINVAL;
1129 else if (mac_header_len > 0)
1130 memcpy(skb_mac_header(entry->skb),
1131 nla_data(nfqa[NFQA_L2HDR]),
1132 mac_header_len);
1133 }
1134
1135 return 0;
1136 }
1137
nfqnl_recv_verdict(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const nfqa[])1138 static int nfqnl_recv_verdict(struct net *net, struct sock *ctnl,
1139 struct sk_buff *skb,
1140 const struct nlmsghdr *nlh,
1141 const struct nlattr * const nfqa[])
1142 {
1143 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1144 u_int16_t queue_num = ntohs(nfmsg->res_id);
1145 struct nfqnl_msg_verdict_hdr *vhdr;
1146 struct nfqnl_instance *queue;
1147 unsigned int verdict;
1148 struct nf_queue_entry *entry;
1149 enum ip_conntrack_info uninitialized_var(ctinfo);
1150 struct nfnl_ct_hook *nfnl_ct;
1151 struct nf_conn *ct = NULL;
1152 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1153 int err;
1154
1155 queue = verdict_instance_lookup(q, queue_num,
1156 NETLINK_CB(skb).portid);
1157 if (IS_ERR(queue))
1158 return PTR_ERR(queue);
1159
1160 vhdr = verdicthdr_get(nfqa);
1161 if (!vhdr)
1162 return -EINVAL;
1163
1164 verdict = ntohl(vhdr->verdict);
1165
1166 entry = find_dequeue_entry(queue, ntohl(vhdr->id));
1167 if (entry == NULL)
1168 return -ENOENT;
1169
1170 /* rcu lock already held from nfnl->call_rcu. */
1171 nfnl_ct = rcu_dereference(nfnl_ct_hook);
1172
1173 if (nfqa[NFQA_CT]) {
1174 if (nfnl_ct != NULL)
1175 ct = nfqnl_ct_parse(nfnl_ct, nlh, nfqa, entry, &ctinfo);
1176 }
1177
1178 if (entry->state.pf == PF_BRIDGE) {
1179 err = nfqa_parse_bridge(entry, nfqa);
1180 if (err < 0)
1181 return err;
1182 }
1183
1184 if (nfqa[NFQA_PAYLOAD]) {
1185 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
1186 int diff = payload_len - entry->skb->len;
1187
1188 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
1189 payload_len, entry, diff) < 0)
1190 verdict = NF_DROP;
1191
1192 if (ct && diff)
1193 nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
1194 }
1195
1196 if (nfqa[NFQA_MARK])
1197 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1198
1199 nf_reinject(entry, verdict);
1200 return 0;
1201 }
1202
nfqnl_recv_unsupp(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const nfqa[])1203 static int nfqnl_recv_unsupp(struct net *net, struct sock *ctnl,
1204 struct sk_buff *skb, const struct nlmsghdr *nlh,
1205 const struct nlattr * const nfqa[])
1206 {
1207 return -ENOTSUPP;
1208 }
1209
1210 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
1211 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
1212 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
1213 };
1214
1215 static const struct nf_queue_handler nfqh = {
1216 .outfn = &nfqnl_enqueue_packet,
1217 .nf_hook_drop = &nfqnl_nf_hook_drop,
1218 };
1219
nfqnl_recv_config(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const nfqa[])1220 static int nfqnl_recv_config(struct net *net, struct sock *ctnl,
1221 struct sk_buff *skb, const struct nlmsghdr *nlh,
1222 const struct nlattr * const nfqa[])
1223 {
1224 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1225 u_int16_t queue_num = ntohs(nfmsg->res_id);
1226 struct nfqnl_instance *queue;
1227 struct nfqnl_msg_config_cmd *cmd = NULL;
1228 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1229 __u32 flags = 0, mask = 0;
1230 int ret = 0;
1231
1232 if (nfqa[NFQA_CFG_CMD]) {
1233 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1234
1235 /* Obsolete commands without queue context */
1236 switch (cmd->command) {
1237 case NFQNL_CFG_CMD_PF_BIND: return 0;
1238 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1239 }
1240 }
1241
1242 /* Check if we support these flags in first place, dependencies should
1243 * be there too not to break atomicity.
1244 */
1245 if (nfqa[NFQA_CFG_FLAGS]) {
1246 if (!nfqa[NFQA_CFG_MASK]) {
1247 /* A mask is needed to specify which flags are being
1248 * changed.
1249 */
1250 return -EINVAL;
1251 }
1252
1253 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1254 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1255
1256 if (flags >= NFQA_CFG_F_MAX)
1257 return -EOPNOTSUPP;
1258
1259 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
1260 if (flags & mask & NFQA_CFG_F_SECCTX)
1261 return -EOPNOTSUPP;
1262 #endif
1263 if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
1264 !rcu_access_pointer(nfnl_ct_hook)) {
1265 #ifdef CONFIG_MODULES
1266 nfnl_unlock(NFNL_SUBSYS_QUEUE);
1267 request_module("ip_conntrack_netlink");
1268 nfnl_lock(NFNL_SUBSYS_QUEUE);
1269 if (rcu_access_pointer(nfnl_ct_hook))
1270 return -EAGAIN;
1271 #endif
1272 return -EOPNOTSUPP;
1273 }
1274 }
1275
1276 rcu_read_lock();
1277 queue = instance_lookup(q, queue_num);
1278 if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1279 ret = -EPERM;
1280 goto err_out_unlock;
1281 }
1282
1283 if (cmd != NULL) {
1284 switch (cmd->command) {
1285 case NFQNL_CFG_CMD_BIND:
1286 if (queue) {
1287 ret = -EBUSY;
1288 goto err_out_unlock;
1289 }
1290 queue = instance_create(q, queue_num,
1291 NETLINK_CB(skb).portid);
1292 if (IS_ERR(queue)) {
1293 ret = PTR_ERR(queue);
1294 goto err_out_unlock;
1295 }
1296 break;
1297 case NFQNL_CFG_CMD_UNBIND:
1298 if (!queue) {
1299 ret = -ENODEV;
1300 goto err_out_unlock;
1301 }
1302 instance_destroy(q, queue);
1303 goto err_out_unlock;
1304 case NFQNL_CFG_CMD_PF_BIND:
1305 case NFQNL_CFG_CMD_PF_UNBIND:
1306 break;
1307 default:
1308 ret = -ENOTSUPP;
1309 goto err_out_unlock;
1310 }
1311 }
1312
1313 if (!queue) {
1314 ret = -ENODEV;
1315 goto err_out_unlock;
1316 }
1317
1318 if (nfqa[NFQA_CFG_PARAMS]) {
1319 struct nfqnl_msg_config_params *params =
1320 nla_data(nfqa[NFQA_CFG_PARAMS]);
1321
1322 nfqnl_set_mode(queue, params->copy_mode,
1323 ntohl(params->copy_range));
1324 }
1325
1326 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1327 __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1328
1329 spin_lock_bh(&queue->lock);
1330 queue->queue_maxlen = ntohl(*queue_maxlen);
1331 spin_unlock_bh(&queue->lock);
1332 }
1333
1334 if (nfqa[NFQA_CFG_FLAGS]) {
1335 spin_lock_bh(&queue->lock);
1336 queue->flags &= ~mask;
1337 queue->flags |= flags & mask;
1338 spin_unlock_bh(&queue->lock);
1339 }
1340
1341 err_out_unlock:
1342 rcu_read_unlock();
1343 return ret;
1344 }
1345
1346 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1347 [NFQNL_MSG_PACKET] = { .call_rcu = nfqnl_recv_unsupp,
1348 .attr_count = NFQA_MAX, },
1349 [NFQNL_MSG_VERDICT] = { .call_rcu = nfqnl_recv_verdict,
1350 .attr_count = NFQA_MAX,
1351 .policy = nfqa_verdict_policy },
1352 [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config,
1353 .attr_count = NFQA_CFG_MAX,
1354 .policy = nfqa_cfg_policy },
1355 [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
1356 .attr_count = NFQA_MAX,
1357 .policy = nfqa_verdict_batch_policy },
1358 };
1359
1360 static const struct nfnetlink_subsystem nfqnl_subsys = {
1361 .name = "nf_queue",
1362 .subsys_id = NFNL_SUBSYS_QUEUE,
1363 .cb_count = NFQNL_MSG_MAX,
1364 .cb = nfqnl_cb,
1365 };
1366
1367 #ifdef CONFIG_PROC_FS
1368 struct iter_state {
1369 struct seq_net_private p;
1370 unsigned int bucket;
1371 };
1372
get_first(struct seq_file * seq)1373 static struct hlist_node *get_first(struct seq_file *seq)
1374 {
1375 struct iter_state *st = seq->private;
1376 struct net *net;
1377 struct nfnl_queue_net *q;
1378
1379 if (!st)
1380 return NULL;
1381
1382 net = seq_file_net(seq);
1383 q = nfnl_queue_pernet(net);
1384 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1385 if (!hlist_empty(&q->instance_table[st->bucket]))
1386 return q->instance_table[st->bucket].first;
1387 }
1388 return NULL;
1389 }
1390
get_next(struct seq_file * seq,struct hlist_node * h)1391 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1392 {
1393 struct iter_state *st = seq->private;
1394 struct net *net = seq_file_net(seq);
1395
1396 h = h->next;
1397 while (!h) {
1398 struct nfnl_queue_net *q;
1399
1400 if (++st->bucket >= INSTANCE_BUCKETS)
1401 return NULL;
1402
1403 q = nfnl_queue_pernet(net);
1404 h = q->instance_table[st->bucket].first;
1405 }
1406 return h;
1407 }
1408
get_idx(struct seq_file * seq,loff_t pos)1409 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1410 {
1411 struct hlist_node *head;
1412 head = get_first(seq);
1413
1414 if (head)
1415 while (pos && (head = get_next(seq, head)))
1416 pos--;
1417 return pos ? NULL : head;
1418 }
1419
seq_start(struct seq_file * s,loff_t * pos)1420 static void *seq_start(struct seq_file *s, loff_t *pos)
1421 __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1422 {
1423 spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1424 return get_idx(s, *pos);
1425 }
1426
seq_next(struct seq_file * s,void * v,loff_t * pos)1427 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1428 {
1429 (*pos)++;
1430 return get_next(s, v);
1431 }
1432
seq_stop(struct seq_file * s,void * v)1433 static void seq_stop(struct seq_file *s, void *v)
1434 __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1435 {
1436 spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1437 }
1438
seq_show(struct seq_file * s,void * v)1439 static int seq_show(struct seq_file *s, void *v)
1440 {
1441 const struct nfqnl_instance *inst = v;
1442
1443 seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
1444 inst->queue_num,
1445 inst->peer_portid, inst->queue_total,
1446 inst->copy_mode, inst->copy_range,
1447 inst->queue_dropped, inst->queue_user_dropped,
1448 inst->id_sequence, 1);
1449 return 0;
1450 }
1451
1452 static const struct seq_operations nfqnl_seq_ops = {
1453 .start = seq_start,
1454 .next = seq_next,
1455 .stop = seq_stop,
1456 .show = seq_show,
1457 };
1458
nfqnl_open(struct inode * inode,struct file * file)1459 static int nfqnl_open(struct inode *inode, struct file *file)
1460 {
1461 return seq_open_net(inode, file, &nfqnl_seq_ops,
1462 sizeof(struct iter_state));
1463 }
1464
1465 static const struct file_operations nfqnl_file_ops = {
1466 .owner = THIS_MODULE,
1467 .open = nfqnl_open,
1468 .read = seq_read,
1469 .llseek = seq_lseek,
1470 .release = seq_release_net,
1471 };
1472
1473 #endif /* PROC_FS */
1474
nfnl_queue_net_init(struct net * net)1475 static int __net_init nfnl_queue_net_init(struct net *net)
1476 {
1477 unsigned int i;
1478 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1479
1480 for (i = 0; i < INSTANCE_BUCKETS; i++)
1481 INIT_HLIST_HEAD(&q->instance_table[i]);
1482
1483 spin_lock_init(&q->instances_lock);
1484
1485 #ifdef CONFIG_PROC_FS
1486 if (!proc_create("nfnetlink_queue", 0440,
1487 net->nf.proc_netfilter, &nfqnl_file_ops))
1488 return -ENOMEM;
1489 #endif
1490 nf_register_queue_handler(net, &nfqh);
1491 return 0;
1492 }
1493
nfnl_queue_net_exit(struct net * net)1494 static void __net_exit nfnl_queue_net_exit(struct net *net)
1495 {
1496 nf_unregister_queue_handler(net);
1497 #ifdef CONFIG_PROC_FS
1498 remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1499 #endif
1500 }
1501
nfnl_queue_net_exit_batch(struct list_head * net_exit_list)1502 static void nfnl_queue_net_exit_batch(struct list_head *net_exit_list)
1503 {
1504 synchronize_rcu();
1505 }
1506
1507 static struct pernet_operations nfnl_queue_net_ops = {
1508 .init = nfnl_queue_net_init,
1509 .exit = nfnl_queue_net_exit,
1510 .exit_batch = nfnl_queue_net_exit_batch,
1511 .id = &nfnl_queue_net_id,
1512 .size = sizeof(struct nfnl_queue_net),
1513 };
1514
nfnetlink_queue_init(void)1515 static int __init nfnetlink_queue_init(void)
1516 {
1517 int status;
1518
1519 status = register_pernet_subsys(&nfnl_queue_net_ops);
1520 if (status < 0) {
1521 pr_err("nf_queue: failed to register pernet ops\n");
1522 goto out;
1523 }
1524
1525 netlink_register_notifier(&nfqnl_rtnl_notifier);
1526 status = nfnetlink_subsys_register(&nfqnl_subsys);
1527 if (status < 0) {
1528 pr_err("nf_queue: failed to create netlink socket\n");
1529 goto cleanup_netlink_notifier;
1530 }
1531
1532 status = register_netdevice_notifier(&nfqnl_dev_notifier);
1533 if (status < 0) {
1534 pr_err("nf_queue: failed to register netdevice notifier\n");
1535 goto cleanup_netlink_subsys;
1536 }
1537
1538 return status;
1539
1540 cleanup_netlink_subsys:
1541 nfnetlink_subsys_unregister(&nfqnl_subsys);
1542 cleanup_netlink_notifier:
1543 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1544 unregister_pernet_subsys(&nfnl_queue_net_ops);
1545 out:
1546 return status;
1547 }
1548
nfnetlink_queue_fini(void)1549 static void __exit nfnetlink_queue_fini(void)
1550 {
1551 unregister_netdevice_notifier(&nfqnl_dev_notifier);
1552 nfnetlink_subsys_unregister(&nfqnl_subsys);
1553 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1554 unregister_pernet_subsys(&nfnl_queue_net_ops);
1555
1556 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1557 }
1558
1559 MODULE_DESCRIPTION("netfilter packet queue handler");
1560 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1561 MODULE_LICENSE("GPL");
1562 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1563
1564 module_init(nfnetlink_queue_init);
1565 module_exit(nfnetlink_queue_fini);
1566