1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * This is a module which is used for queueing packets and communicating with
4 * userspace via nfnetlink.
5 *
6 * (C) 2005 by Harald Welte <laforge@netfilter.org>
7 * (C) 2007 by Patrick McHardy <kaber@trash.net>
8 *
9 * Based on the old ipv4-only ip_queue.c:
10 * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
11 * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
12 */
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/module.h>
17 #include <linux/skbuff.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/slab.h>
21 #include <linux/notifier.h>
22 #include <linux/netdevice.h>
23 #include <linux/netfilter.h>
24 #include <linux/proc_fs.h>
25 #include <linux/netfilter_ipv4.h>
26 #include <linux/netfilter_ipv6.h>
27 #include <linux/netfilter_bridge.h>
28 #include <linux/netfilter/nfnetlink.h>
29 #include <linux/netfilter/nfnetlink_queue.h>
30 #include <linux/netfilter/nf_conntrack_common.h>
31 #include <linux/list.h>
32 #include <linux/cgroup-defs.h>
33 #include <net/gso.h>
34 #include <net/sock.h>
35 #include <net/tcp_states.h>
36 #include <net/netfilter/nf_queue.h>
37 #include <net/netns/generic.h>
38
39 #include <linux/atomic.h>
40
41 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
42 #include "../bridge/br_private.h"
43 #endif
44
45 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
46 #include <net/netfilter/nf_conntrack.h>
47 #endif
48
49 #define NFQNL_QMAX_DEFAULT 1024
50
51 /* We're using struct nlattr which has 16bit nla_len. Note that nla_len
52 * includes the header length. Thus, the maximum packet length that we
53 * support is 65531 bytes. We send truncated packets if the specified length
54 * is larger than that. Userspace can check for presence of NFQA_CAP_LEN
55 * attribute to detect truncation.
56 */
57 #define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN)
58
59 struct nfqnl_instance {
60 struct hlist_node hlist; /* global list of queues */
61 struct rcu_head rcu;
62
63 u32 peer_portid;
64 unsigned int queue_maxlen;
65 unsigned int copy_range;
66 unsigned int queue_dropped;
67 unsigned int queue_user_dropped;
68
69
70 u_int16_t queue_num; /* number of this queue */
71 u_int8_t copy_mode;
72 u_int32_t flags; /* Set using NFQA_CFG_FLAGS */
73 /*
74 * Following fields are dirtied for each queued packet,
75 * keep them in same cache line if possible.
76 */
77 spinlock_t lock ____cacheline_aligned_in_smp;
78 unsigned int queue_total;
79 unsigned int id_sequence; /* 'sequence' of pkt ids */
80 struct list_head queue_list; /* packets in queue */
81 };
82
83 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
84
85 static unsigned int nfnl_queue_net_id __read_mostly;
86
87 #define INSTANCE_BUCKETS 16
88 struct nfnl_queue_net {
89 spinlock_t instances_lock;
90 struct hlist_head instance_table[INSTANCE_BUCKETS];
91 };
92
nfnl_queue_pernet(struct net * net)93 static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net)
94 {
95 return net_generic(net, nfnl_queue_net_id);
96 }
97
instance_hashfn(u_int16_t queue_num)98 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
99 {
100 return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS;
101 }
102
103 static struct nfqnl_instance *
instance_lookup(struct nfnl_queue_net * q,u_int16_t queue_num)104 instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num)
105 {
106 struct hlist_head *head;
107 struct nfqnl_instance *inst;
108
109 head = &q->instance_table[instance_hashfn(queue_num)];
110 hlist_for_each_entry_rcu(inst, head, hlist) {
111 if (inst->queue_num == queue_num)
112 return inst;
113 }
114 return NULL;
115 }
116
117 static struct nfqnl_instance *
instance_create(struct nfnl_queue_net * q,u_int16_t queue_num,u32 portid)118 instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid)
119 {
120 struct nfqnl_instance *inst;
121 unsigned int h;
122 int err;
123
124 spin_lock(&q->instances_lock);
125 if (instance_lookup(q, queue_num)) {
126 err = -EEXIST;
127 goto out_unlock;
128 }
129
130 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
131 if (!inst) {
132 err = -ENOMEM;
133 goto out_unlock;
134 }
135
136 inst->queue_num = queue_num;
137 inst->peer_portid = portid;
138 inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
139 inst->copy_range = NFQNL_MAX_COPY_RANGE;
140 inst->copy_mode = NFQNL_COPY_NONE;
141 spin_lock_init(&inst->lock);
142 INIT_LIST_HEAD(&inst->queue_list);
143
144 if (!try_module_get(THIS_MODULE)) {
145 err = -EAGAIN;
146 goto out_free;
147 }
148
149 h = instance_hashfn(queue_num);
150 hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]);
151
152 spin_unlock(&q->instances_lock);
153
154 return inst;
155
156 out_free:
157 kfree(inst);
158 out_unlock:
159 spin_unlock(&q->instances_lock);
160 return ERR_PTR(err);
161 }
162
163 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
164 unsigned long data);
165
166 static void
instance_destroy_rcu(struct rcu_head * head)167 instance_destroy_rcu(struct rcu_head *head)
168 {
169 struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
170 rcu);
171
172 rcu_read_lock();
173 nfqnl_flush(inst, NULL, 0);
174 rcu_read_unlock();
175 kfree(inst);
176 module_put(THIS_MODULE);
177 }
178
179 static void
__instance_destroy(struct nfqnl_instance * inst)180 __instance_destroy(struct nfqnl_instance *inst)
181 {
182 hlist_del_rcu(&inst->hlist);
183 call_rcu(&inst->rcu, instance_destroy_rcu);
184 }
185
186 static void
instance_destroy(struct nfnl_queue_net * q,struct nfqnl_instance * inst)187 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
188 {
189 spin_lock(&q->instances_lock);
190 __instance_destroy(inst);
191 spin_unlock(&q->instances_lock);
192 }
193
194 static inline void
__enqueue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)195 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
196 {
197 list_add_tail(&entry->list, &queue->queue_list);
198 queue->queue_total++;
199 }
200
201 static void
__dequeue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)202 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
203 {
204 list_del(&entry->list);
205 queue->queue_total--;
206 }
207
208 static struct nf_queue_entry *
find_dequeue_entry(struct nfqnl_instance * queue,unsigned int id)209 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
210 {
211 struct nf_queue_entry *entry = NULL, *i;
212
213 spin_lock_bh(&queue->lock);
214
215 list_for_each_entry(i, &queue->queue_list, list) {
216 if (i->id == id) {
217 entry = i;
218 break;
219 }
220 }
221
222 if (entry)
223 __dequeue_entry(queue, entry);
224
225 spin_unlock_bh(&queue->lock);
226
227 return entry;
228 }
229
nf_iterate(struct sk_buff * skb,struct nf_hook_state * state,const struct nf_hook_entries * hooks,unsigned int * index)230 static unsigned int nf_iterate(struct sk_buff *skb,
231 struct nf_hook_state *state,
232 const struct nf_hook_entries *hooks,
233 unsigned int *index)
234 {
235 const struct nf_hook_entry *hook;
236 unsigned int verdict, i = *index;
237
238 while (i < hooks->num_hook_entries) {
239 hook = &hooks->hooks[i];
240 repeat:
241 verdict = nf_hook_entry_hookfn(hook, skb, state);
242 if (verdict != NF_ACCEPT) {
243 *index = i;
244 if (verdict != NF_REPEAT)
245 return verdict;
246 goto repeat;
247 }
248 i++;
249 }
250
251 *index = i;
252 return NF_ACCEPT;
253 }
254
nf_hook_entries_head(const struct net * net,u8 pf,u8 hooknum)255 static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum)
256 {
257 switch (pf) {
258 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
259 case NFPROTO_BRIDGE:
260 return rcu_dereference(net->nf.hooks_bridge[hooknum]);
261 #endif
262 case NFPROTO_IPV4:
263 return rcu_dereference(net->nf.hooks_ipv4[hooknum]);
264 case NFPROTO_IPV6:
265 return rcu_dereference(net->nf.hooks_ipv6[hooknum]);
266 default:
267 WARN_ON_ONCE(1);
268 return NULL;
269 }
270
271 return NULL;
272 }
273
nf_ip_reroute(struct sk_buff * skb,const struct nf_queue_entry * entry)274 static int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry)
275 {
276 #ifdef CONFIG_INET
277 const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
278
279 if (entry->state.hook == NF_INET_LOCAL_OUT) {
280 const struct iphdr *iph = ip_hdr(skb);
281
282 if (!(iph->tos == rt_info->tos &&
283 skb->mark == rt_info->mark &&
284 iph->daddr == rt_info->daddr &&
285 iph->saddr == rt_info->saddr))
286 return ip_route_me_harder(entry->state.net, entry->state.sk,
287 skb, RTN_UNSPEC);
288 }
289 #endif
290 return 0;
291 }
292
nf_reroute(struct sk_buff * skb,struct nf_queue_entry * entry)293 static int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
294 {
295 const struct nf_ipv6_ops *v6ops;
296 int ret = 0;
297
298 switch (entry->state.pf) {
299 case AF_INET:
300 ret = nf_ip_reroute(skb, entry);
301 break;
302 case AF_INET6:
303 v6ops = rcu_dereference(nf_ipv6_ops);
304 if (v6ops)
305 ret = v6ops->reroute(skb, entry);
306 break;
307 }
308 return ret;
309 }
310
311 /* caller must hold rcu read-side lock */
nf_reinject(struct nf_queue_entry * entry,unsigned int verdict)312 static void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
313 {
314 const struct nf_hook_entry *hook_entry;
315 const struct nf_hook_entries *hooks;
316 struct sk_buff *skb = entry->skb;
317 const struct net *net;
318 unsigned int i;
319 int err;
320 u8 pf;
321
322 net = entry->state.net;
323 pf = entry->state.pf;
324
325 hooks = nf_hook_entries_head(net, pf, entry->state.hook);
326
327 i = entry->hook_index;
328 if (!hooks || i >= hooks->num_hook_entries) {
329 kfree_skb_reason(skb, SKB_DROP_REASON_NETFILTER_DROP);
330 nf_queue_entry_free(entry);
331 return;
332 }
333
334 hook_entry = &hooks->hooks[i];
335
336 /* Continue traversal iff userspace said ok... */
337 if (verdict == NF_REPEAT)
338 verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state);
339
340 if (verdict == NF_ACCEPT) {
341 if (nf_reroute(skb, entry) < 0)
342 verdict = NF_DROP;
343 }
344
345 if (verdict == NF_ACCEPT) {
346 next_hook:
347 ++i;
348 verdict = nf_iterate(skb, &entry->state, hooks, &i);
349 }
350
351 switch (verdict & NF_VERDICT_MASK) {
352 case NF_ACCEPT:
353 case NF_STOP:
354 local_bh_disable();
355 entry->state.okfn(entry->state.net, entry->state.sk, skb);
356 local_bh_enable();
357 break;
358 case NF_QUEUE:
359 err = nf_queue(skb, &entry->state, i, verdict);
360 if (err == 1)
361 goto next_hook;
362 break;
363 case NF_STOLEN:
364 break;
365 default:
366 kfree_skb(skb);
367 }
368
369 nf_queue_entry_free(entry);
370 }
371
nfqnl_reinject(struct nf_queue_entry * entry,unsigned int verdict)372 static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict)
373 {
374 const struct nf_ct_hook *ct_hook;
375
376 if (verdict == NF_ACCEPT ||
377 verdict == NF_REPEAT ||
378 verdict == NF_STOP) {
379 unsigned int ct_verdict = verdict;
380
381 rcu_read_lock();
382 ct_hook = rcu_dereference(nf_ct_hook);
383 if (ct_hook)
384 ct_verdict = ct_hook->update(entry->state.net, entry->skb);
385 rcu_read_unlock();
386
387 switch (ct_verdict & NF_VERDICT_MASK) {
388 case NF_ACCEPT:
389 /* follow userspace verdict, could be REPEAT */
390 break;
391 case NF_STOLEN:
392 nf_queue_entry_free(entry);
393 return;
394 default:
395 verdict = ct_verdict & NF_VERDICT_MASK;
396 break;
397 }
398 }
399 nf_reinject(entry, verdict);
400 }
401
402 static void
nfqnl_flush(struct nfqnl_instance * queue,nfqnl_cmpfn cmpfn,unsigned long data)403 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
404 {
405 struct nf_queue_entry *entry, *next;
406
407 spin_lock_bh(&queue->lock);
408 list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
409 if (!cmpfn || cmpfn(entry, data)) {
410 list_del(&entry->list);
411 queue->queue_total--;
412 nfqnl_reinject(entry, NF_DROP);
413 }
414 }
415 spin_unlock_bh(&queue->lock);
416 }
417
418 static int
nfqnl_put_packet_info(struct sk_buff * nlskb,struct sk_buff * packet,bool csum_verify)419 nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet,
420 bool csum_verify)
421 {
422 __u32 flags = 0;
423
424 if (packet->ip_summed == CHECKSUM_PARTIAL)
425 flags = NFQA_SKB_CSUMNOTREADY;
426 else if (csum_verify)
427 flags = NFQA_SKB_CSUM_NOTVERIFIED;
428
429 if (skb_is_gso(packet))
430 flags |= NFQA_SKB_GSO;
431
432 return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0;
433 }
434
nfqnl_put_sk_uidgid(struct sk_buff * skb,struct sock * sk)435 static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
436 {
437 const struct cred *cred;
438
439 if (!sk_fullsock(sk))
440 return 0;
441
442 read_lock_bh(&sk->sk_callback_lock);
443 if (sk->sk_socket && sk->sk_socket->file) {
444 cred = sk->sk_socket->file->f_cred;
445 if (nla_put_be32(skb, NFQA_UID,
446 htonl(from_kuid_munged(&init_user_ns, cred->fsuid))))
447 goto nla_put_failure;
448 if (nla_put_be32(skb, NFQA_GID,
449 htonl(from_kgid_munged(&init_user_ns, cred->fsgid))))
450 goto nla_put_failure;
451 }
452 read_unlock_bh(&sk->sk_callback_lock);
453 return 0;
454
455 nla_put_failure:
456 read_unlock_bh(&sk->sk_callback_lock);
457 return -1;
458 }
459
nfqnl_put_sk_classid(struct sk_buff * skb,struct sock * sk)460 static int nfqnl_put_sk_classid(struct sk_buff *skb, struct sock *sk)
461 {
462 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
463 if (sk && sk_fullsock(sk)) {
464 u32 classid = sock_cgroup_classid(&sk->sk_cgrp_data);
465
466 if (classid && nla_put_be32(skb, NFQA_CGROUP_CLASSID, htonl(classid)))
467 return -1;
468 }
469 #endif
470 return 0;
471 }
472
nfqnl_get_sk_secctx(struct sk_buff * skb,char ** secdata)473 static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
474 {
475 u32 seclen = 0;
476 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
477 if (!skb || !sk_fullsock(skb->sk))
478 return 0;
479
480 read_lock_bh(&skb->sk->sk_callback_lock);
481
482 if (skb->secmark)
483 security_secid_to_secctx(skb->secmark, secdata, &seclen);
484
485 read_unlock_bh(&skb->sk->sk_callback_lock);
486 #endif
487 return seclen;
488 }
489
nfqnl_get_bridge_size(struct nf_queue_entry * entry)490 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
491 {
492 struct sk_buff *entskb = entry->skb;
493 u32 nlalen = 0;
494
495 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
496 return 0;
497
498 if (skb_vlan_tag_present(entskb))
499 nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
500 nla_total_size(sizeof(__be16)));
501
502 if (entskb->network_header > entskb->mac_header)
503 nlalen += nla_total_size((entskb->network_header -
504 entskb->mac_header));
505
506 return nlalen;
507 }
508
nfqnl_put_bridge(struct nf_queue_entry * entry,struct sk_buff * skb)509 static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
510 {
511 struct sk_buff *entskb = entry->skb;
512
513 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
514 return 0;
515
516 if (skb_vlan_tag_present(entskb)) {
517 struct nlattr *nest;
518
519 nest = nla_nest_start(skb, NFQA_VLAN);
520 if (!nest)
521 goto nla_put_failure;
522
523 if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
524 nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
525 goto nla_put_failure;
526
527 nla_nest_end(skb, nest);
528 }
529
530 if (entskb->mac_header < entskb->network_header) {
531 int len = (int)(entskb->network_header - entskb->mac_header);
532
533 if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb)))
534 goto nla_put_failure;
535 }
536
537 return 0;
538
539 nla_put_failure:
540 return -1;
541 }
542
nf_queue_checksum_help(struct sk_buff * entskb)543 static int nf_queue_checksum_help(struct sk_buff *entskb)
544 {
545 if (skb_csum_is_sctp(entskb))
546 return skb_crc32c_csum_help(entskb);
547
548 return skb_checksum_help(entskb);
549 }
550
551 static struct sk_buff *
nfqnl_build_packet_message(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry,__be32 ** packet_id_ptr)552 nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
553 struct nf_queue_entry *entry,
554 __be32 **packet_id_ptr)
555 {
556 size_t size;
557 size_t data_len = 0, cap_len = 0;
558 unsigned int hlen = 0;
559 struct sk_buff *skb;
560 struct nlattr *nla;
561 struct nfqnl_msg_packet_hdr *pmsg;
562 struct nlmsghdr *nlh;
563 struct sk_buff *entskb = entry->skb;
564 struct net_device *indev;
565 struct net_device *outdev;
566 struct nf_conn *ct = NULL;
567 enum ip_conntrack_info ctinfo = 0;
568 const struct nfnl_ct_hook *nfnl_ct;
569 bool csum_verify;
570 char *secdata = NULL;
571 u32 seclen = 0;
572 ktime_t tstamp;
573
574 size = nlmsg_total_size(sizeof(struct nfgenmsg))
575 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
576 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
577 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
578 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
579 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
580 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
581 #endif
582 + nla_total_size(sizeof(u_int32_t)) /* mark */
583 + nla_total_size(sizeof(u_int32_t)) /* priority */
584 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
585 + nla_total_size(sizeof(u_int32_t)) /* skbinfo */
586 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
587 + nla_total_size(sizeof(u_int32_t)) /* classid */
588 #endif
589 + nla_total_size(sizeof(u_int32_t)); /* cap_len */
590
591 tstamp = skb_tstamp_cond(entskb, false);
592 if (tstamp)
593 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
594
595 size += nfqnl_get_bridge_size(entry);
596
597 if (entry->state.hook <= NF_INET_FORWARD ||
598 (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
599 csum_verify = !skb_csum_unnecessary(entskb);
600 else
601 csum_verify = false;
602
603 outdev = entry->state.out;
604
605 switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) {
606 case NFQNL_COPY_META:
607 case NFQNL_COPY_NONE:
608 break;
609
610 case NFQNL_COPY_PACKET:
611 if (!(queue->flags & NFQA_CFG_F_GSO) &&
612 entskb->ip_summed == CHECKSUM_PARTIAL &&
613 nf_queue_checksum_help(entskb))
614 return NULL;
615
616 data_len = READ_ONCE(queue->copy_range);
617 if (data_len > entskb->len)
618 data_len = entskb->len;
619
620 hlen = skb_zerocopy_headlen(entskb);
621 hlen = min_t(unsigned int, hlen, data_len);
622 size += sizeof(struct nlattr) + hlen;
623 cap_len = entskb->len;
624 break;
625 }
626
627 nfnl_ct = rcu_dereference(nfnl_ct_hook);
628
629 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
630 if (queue->flags & NFQA_CFG_F_CONNTRACK) {
631 if (nfnl_ct != NULL) {
632 ct = nf_ct_get(entskb, &ctinfo);
633 if (ct != NULL)
634 size += nfnl_ct->build_size(ct);
635 }
636 }
637 #endif
638
639 if (queue->flags & NFQA_CFG_F_UID_GID) {
640 size += (nla_total_size(sizeof(u_int32_t)) /* uid */
641 + nla_total_size(sizeof(u_int32_t))); /* gid */
642 }
643
644 if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
645 seclen = nfqnl_get_sk_secctx(entskb, &secdata);
646 if (seclen)
647 size += nla_total_size(seclen);
648 }
649
650 skb = alloc_skb(size, GFP_ATOMIC);
651 if (!skb) {
652 skb_tx_error(entskb);
653 goto nlmsg_failure;
654 }
655
656 nlh = nfnl_msg_put(skb, 0, 0,
657 nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET),
658 0, entry->state.pf, NFNETLINK_V0,
659 htons(queue->queue_num));
660 if (!nlh) {
661 skb_tx_error(entskb);
662 kfree_skb(skb);
663 goto nlmsg_failure;
664 }
665
666 nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
667 pmsg = nla_data(nla);
668 pmsg->hw_protocol = entskb->protocol;
669 pmsg->hook = entry->state.hook;
670 *packet_id_ptr = &pmsg->packet_id;
671
672 indev = entry->state.in;
673 if (indev) {
674 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
675 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
676 goto nla_put_failure;
677 #else
678 if (entry->state.pf == PF_BRIDGE) {
679 /* Case 1: indev is physical input device, we need to
680 * look for bridge group (when called from
681 * netfilter_bridge) */
682 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
683 htonl(indev->ifindex)) ||
684 /* this is the bridge group "brX" */
685 /* rcu_read_lock()ed by __nf_queue */
686 nla_put_be32(skb, NFQA_IFINDEX_INDEV,
687 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
688 goto nla_put_failure;
689 } else {
690 int physinif;
691
692 /* Case 2: indev is bridge group, we need to look for
693 * physical device (when called from ipv4) */
694 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
695 htonl(indev->ifindex)))
696 goto nla_put_failure;
697
698 physinif = nf_bridge_get_physinif(entskb);
699 if (physinif &&
700 nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
701 htonl(physinif)))
702 goto nla_put_failure;
703 }
704 #endif
705 }
706
707 if (outdev) {
708 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
709 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
710 goto nla_put_failure;
711 #else
712 if (entry->state.pf == PF_BRIDGE) {
713 /* Case 1: outdev is physical output device, we need to
714 * look for bridge group (when called from
715 * netfilter_bridge) */
716 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
717 htonl(outdev->ifindex)) ||
718 /* this is the bridge group "brX" */
719 /* rcu_read_lock()ed by __nf_queue */
720 nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
721 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
722 goto nla_put_failure;
723 } else {
724 int physoutif;
725
726 /* Case 2: outdev is bridge group, we need to look for
727 * physical output device (when called from ipv4) */
728 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
729 htonl(outdev->ifindex)))
730 goto nla_put_failure;
731
732 physoutif = nf_bridge_get_physoutif(entskb);
733 if (physoutif &&
734 nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
735 htonl(physoutif)))
736 goto nla_put_failure;
737 }
738 #endif
739 }
740
741 if (entskb->mark &&
742 nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
743 goto nla_put_failure;
744
745 if (entskb->priority &&
746 nla_put_be32(skb, NFQA_PRIORITY, htonl(entskb->priority)))
747 goto nla_put_failure;
748
749 if (indev && entskb->dev &&
750 skb_mac_header_was_set(entskb) &&
751 skb_mac_header_len(entskb) != 0) {
752 struct nfqnl_msg_packet_hw phw;
753 int len;
754
755 memset(&phw, 0, sizeof(phw));
756 len = dev_parse_header(entskb, phw.hw_addr);
757 if (len) {
758 phw.hw_addrlen = htons(len);
759 if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
760 goto nla_put_failure;
761 }
762 }
763
764 if (nfqnl_put_bridge(entry, skb) < 0)
765 goto nla_put_failure;
766
767 if (entry->state.hook <= NF_INET_FORWARD && tstamp) {
768 struct nfqnl_msg_packet_timestamp ts;
769 struct timespec64 kts = ktime_to_timespec64(tstamp);
770
771 ts.sec = cpu_to_be64(kts.tv_sec);
772 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
773
774 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
775 goto nla_put_failure;
776 }
777
778 if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
779 nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
780 goto nla_put_failure;
781
782 if (nfqnl_put_sk_classid(skb, entskb->sk) < 0)
783 goto nla_put_failure;
784
785 if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
786 goto nla_put_failure;
787
788 if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
789 goto nla_put_failure;
790
791 if (cap_len > data_len &&
792 nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
793 goto nla_put_failure;
794
795 if (nfqnl_put_packet_info(skb, entskb, csum_verify))
796 goto nla_put_failure;
797
798 if (data_len) {
799 struct nlattr *nla;
800
801 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
802 goto nla_put_failure;
803
804 nla = skb_put(skb, sizeof(*nla));
805 nla->nla_type = NFQA_PAYLOAD;
806 nla->nla_len = nla_attr_size(data_len);
807
808 if (skb_zerocopy(skb, entskb, data_len, hlen))
809 goto nla_put_failure;
810 }
811
812 nlh->nlmsg_len = skb->len;
813 if (seclen)
814 security_release_secctx(secdata, seclen);
815 return skb;
816
817 nla_put_failure:
818 skb_tx_error(entskb);
819 kfree_skb(skb);
820 net_err_ratelimited("nf_queue: error creating packet message\n");
821 nlmsg_failure:
822 if (seclen)
823 security_release_secctx(secdata, seclen);
824 return NULL;
825 }
826
nf_ct_drop_unconfirmed(const struct nf_queue_entry * entry)827 static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry)
828 {
829 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
830 static const unsigned long flags = IPS_CONFIRMED | IPS_DYING;
831 struct nf_conn *ct = (void *)skb_nfct(entry->skb);
832 unsigned long status;
833 unsigned int use;
834
835 if (!ct)
836 return false;
837
838 status = READ_ONCE(ct->status);
839 if ((status & flags) == IPS_DYING)
840 return true;
841
842 if (status & IPS_CONFIRMED)
843 return false;
844
845 /* in some cases skb_clone() can occur after initial conntrack
846 * pickup, but conntrack assumes exclusive skb->_nfct ownership for
847 * unconfirmed entries.
848 *
849 * This happens for br_netfilter and with ip multicast routing.
850 * We can't be solved with serialization here because one clone could
851 * have been queued for local delivery.
852 */
853 use = refcount_read(&ct->ct_general.use);
854 if (likely(use == 1))
855 return false;
856
857 /* Can't decrement further? Exclusive ownership. */
858 if (!refcount_dec_not_one(&ct->ct_general.use))
859 return false;
860
861 skb_set_nfct(entry->skb, 0);
862 /* No nf_ct_put(): we already decremented .use and it cannot
863 * drop down to 0.
864 */
865 return true;
866 #endif
867 return false;
868 }
869
870 static int
__nfqnl_enqueue_packet(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry)871 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
872 struct nf_queue_entry *entry)
873 {
874 struct sk_buff *nskb;
875 int err = -ENOBUFS;
876 __be32 *packet_id_ptr;
877 int failopen = 0;
878
879 nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
880 if (nskb == NULL) {
881 err = -ENOMEM;
882 goto err_out;
883 }
884 spin_lock_bh(&queue->lock);
885
886 if (nf_ct_drop_unconfirmed(entry))
887 goto err_out_free_nskb;
888
889 if (queue->queue_total >= queue->queue_maxlen) {
890 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
891 failopen = 1;
892 err = 0;
893 } else {
894 queue->queue_dropped++;
895 net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
896 queue->queue_total);
897 }
898 goto err_out_free_nskb;
899 }
900 entry->id = ++queue->id_sequence;
901 *packet_id_ptr = htonl(entry->id);
902
903 /* nfnetlink_unicast will either free the nskb or add it to a socket */
904 err = nfnetlink_unicast(nskb, net, queue->peer_portid);
905 if (err < 0) {
906 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
907 failopen = 1;
908 err = 0;
909 } else {
910 queue->queue_user_dropped++;
911 }
912 goto err_out_unlock;
913 }
914
915 __enqueue_entry(queue, entry);
916
917 spin_unlock_bh(&queue->lock);
918 return 0;
919
920 err_out_free_nskb:
921 kfree_skb(nskb);
922 err_out_unlock:
923 spin_unlock_bh(&queue->lock);
924 if (failopen)
925 nfqnl_reinject(entry, NF_ACCEPT);
926 err_out:
927 return err;
928 }
929
930 static struct nf_queue_entry *
nf_queue_entry_dup(struct nf_queue_entry * e)931 nf_queue_entry_dup(struct nf_queue_entry *e)
932 {
933 struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
934
935 if (!entry)
936 return NULL;
937
938 if (nf_queue_entry_get_refs(entry))
939 return entry;
940
941 kfree(entry);
942 return NULL;
943 }
944
945 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
946 /* When called from bridge netfilter, skb->data must point to MAC header
947 * before calling skb_gso_segment(). Else, original MAC header is lost
948 * and segmented skbs will be sent to wrong destination.
949 */
nf_bridge_adjust_skb_data(struct sk_buff * skb)950 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
951 {
952 if (nf_bridge_info_get(skb))
953 __skb_push(skb, skb->network_header - skb->mac_header);
954 }
955
nf_bridge_adjust_segmented_data(struct sk_buff * skb)956 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
957 {
958 if (nf_bridge_info_get(skb))
959 __skb_pull(skb, skb->network_header - skb->mac_header);
960 }
961 #else
962 #define nf_bridge_adjust_skb_data(s) do {} while (0)
963 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
964 #endif
965
966 static int
__nfqnl_enqueue_packet_gso(struct net * net,struct nfqnl_instance * queue,struct sk_buff * skb,struct nf_queue_entry * entry)967 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
968 struct sk_buff *skb, struct nf_queue_entry *entry)
969 {
970 int ret = -ENOMEM;
971 struct nf_queue_entry *entry_seg;
972
973 nf_bridge_adjust_segmented_data(skb);
974
975 if (skb->next == NULL) { /* last packet, no need to copy entry */
976 struct sk_buff *gso_skb = entry->skb;
977 entry->skb = skb;
978 ret = __nfqnl_enqueue_packet(net, queue, entry);
979 if (ret)
980 entry->skb = gso_skb;
981 return ret;
982 }
983
984 skb_mark_not_on_list(skb);
985
986 entry_seg = nf_queue_entry_dup(entry);
987 if (entry_seg) {
988 entry_seg->skb = skb;
989 ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
990 if (ret)
991 nf_queue_entry_free(entry_seg);
992 }
993 return ret;
994 }
995
996 static int
nfqnl_enqueue_packet(struct nf_queue_entry * entry,unsigned int queuenum)997 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
998 {
999 unsigned int queued;
1000 struct nfqnl_instance *queue;
1001 struct sk_buff *skb, *segs, *nskb;
1002 int err = -ENOBUFS;
1003 struct net *net = entry->state.net;
1004 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1005
1006 /* rcu_read_lock()ed by nf_hook_thresh */
1007 queue = instance_lookup(q, queuenum);
1008 if (!queue)
1009 return -ESRCH;
1010
1011 if (queue->copy_mode == NFQNL_COPY_NONE)
1012 return -EINVAL;
1013
1014 skb = entry->skb;
1015
1016 switch (entry->state.pf) {
1017 case NFPROTO_IPV4:
1018 skb->protocol = htons(ETH_P_IP);
1019 break;
1020 case NFPROTO_IPV6:
1021 skb->protocol = htons(ETH_P_IPV6);
1022 break;
1023 }
1024
1025 if (!skb_is_gso(skb) || ((queue->flags & NFQA_CFG_F_GSO) && !skb_is_gso_sctp(skb)))
1026 return __nfqnl_enqueue_packet(net, queue, entry);
1027
1028 nf_bridge_adjust_skb_data(skb);
1029 segs = skb_gso_segment(skb, 0);
1030 /* Does not use PTR_ERR to limit the number of error codes that can be
1031 * returned by nf_queue. For instance, callers rely on -ESRCH to
1032 * mean 'ignore this hook'.
1033 */
1034 if (IS_ERR_OR_NULL(segs))
1035 goto out_err;
1036 queued = 0;
1037 err = 0;
1038 skb_list_walk_safe(segs, segs, nskb) {
1039 if (err == 0)
1040 err = __nfqnl_enqueue_packet_gso(net, queue,
1041 segs, entry);
1042 if (err == 0)
1043 queued++;
1044 else
1045 kfree_skb(segs);
1046 }
1047
1048 if (queued) {
1049 if (err) /* some segments are already queued */
1050 nf_queue_entry_free(entry);
1051 kfree_skb(skb);
1052 return 0;
1053 }
1054 out_err:
1055 nf_bridge_adjust_segmented_data(skb);
1056 return err;
1057 }
1058
1059 static int
nfqnl_mangle(void * data,unsigned int data_len,struct nf_queue_entry * e,int diff)1060 nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff)
1061 {
1062 struct sk_buff *nskb;
1063
1064 if (diff < 0) {
1065 unsigned int min_len = skb_transport_offset(e->skb);
1066
1067 if (data_len < min_len)
1068 return -EINVAL;
1069
1070 if (pskb_trim(e->skb, data_len))
1071 return -ENOMEM;
1072 } else if (diff > 0) {
1073 if (data_len > 0xFFFF)
1074 return -EINVAL;
1075 if (diff > skb_tailroom(e->skb)) {
1076 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
1077 diff, GFP_ATOMIC);
1078 if (!nskb)
1079 return -ENOMEM;
1080 kfree_skb(e->skb);
1081 e->skb = nskb;
1082 }
1083 skb_put(e->skb, diff);
1084 }
1085 if (skb_ensure_writable(e->skb, data_len))
1086 return -ENOMEM;
1087 skb_copy_to_linear_data(e->skb, data, data_len);
1088 e->skb->ip_summed = CHECKSUM_NONE;
1089 return 0;
1090 }
1091
1092 static int
nfqnl_set_mode(struct nfqnl_instance * queue,unsigned char mode,unsigned int range)1093 nfqnl_set_mode(struct nfqnl_instance *queue,
1094 unsigned char mode, unsigned int range)
1095 {
1096 int status = 0;
1097
1098 spin_lock_bh(&queue->lock);
1099 switch (mode) {
1100 case NFQNL_COPY_NONE:
1101 case NFQNL_COPY_META:
1102 queue->copy_mode = mode;
1103 queue->copy_range = 0;
1104 break;
1105
1106 case NFQNL_COPY_PACKET:
1107 queue->copy_mode = mode;
1108 if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
1109 queue->copy_range = NFQNL_MAX_COPY_RANGE;
1110 else
1111 queue->copy_range = range;
1112 break;
1113
1114 default:
1115 status = -EINVAL;
1116
1117 }
1118 spin_unlock_bh(&queue->lock);
1119
1120 return status;
1121 }
1122
1123 static int
dev_cmp(struct nf_queue_entry * entry,unsigned long ifindex)1124 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
1125 {
1126 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
1127 int physinif, physoutif;
1128
1129 physinif = nf_bridge_get_physinif(entry->skb);
1130 physoutif = nf_bridge_get_physoutif(entry->skb);
1131
1132 if (physinif == ifindex || physoutif == ifindex)
1133 return 1;
1134 #endif
1135 if (entry->state.in)
1136 if (entry->state.in->ifindex == ifindex)
1137 return 1;
1138 if (entry->state.out)
1139 if (entry->state.out->ifindex == ifindex)
1140 return 1;
1141
1142 return 0;
1143 }
1144
1145 /* drop all packets with either indev or outdev == ifindex from all queue
1146 * instances */
1147 static void
nfqnl_dev_drop(struct net * net,int ifindex)1148 nfqnl_dev_drop(struct net *net, int ifindex)
1149 {
1150 int i;
1151 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1152
1153 rcu_read_lock();
1154
1155 for (i = 0; i < INSTANCE_BUCKETS; i++) {
1156 struct nfqnl_instance *inst;
1157 struct hlist_head *head = &q->instance_table[i];
1158
1159 hlist_for_each_entry_rcu(inst, head, hlist)
1160 nfqnl_flush(inst, dev_cmp, ifindex);
1161 }
1162
1163 rcu_read_unlock();
1164 }
1165
1166 static int
nfqnl_rcv_dev_event(struct notifier_block * this,unsigned long event,void * ptr)1167 nfqnl_rcv_dev_event(struct notifier_block *this,
1168 unsigned long event, void *ptr)
1169 {
1170 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1171
1172 /* Drop any packets associated with the downed device */
1173 if (event == NETDEV_DOWN)
1174 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
1175 return NOTIFY_DONE;
1176 }
1177
1178 static struct notifier_block nfqnl_dev_notifier = {
1179 .notifier_call = nfqnl_rcv_dev_event,
1180 };
1181
nfqnl_nf_hook_drop(struct net * net)1182 static void nfqnl_nf_hook_drop(struct net *net)
1183 {
1184 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1185 int i;
1186
1187 /* This function is also called on net namespace error unwind,
1188 * when pernet_ops->init() failed and ->exit() functions of the
1189 * previous pernet_ops gets called.
1190 *
1191 * This may result in a call to nfqnl_nf_hook_drop() before
1192 * struct nfnl_queue_net was allocated.
1193 */
1194 if (!q)
1195 return;
1196
1197 for (i = 0; i < INSTANCE_BUCKETS; i++) {
1198 struct nfqnl_instance *inst;
1199 struct hlist_head *head = &q->instance_table[i];
1200
1201 hlist_for_each_entry_rcu(inst, head, hlist)
1202 nfqnl_flush(inst, NULL, 0);
1203 }
1204 }
1205
1206 static int
nfqnl_rcv_nl_event(struct notifier_block * this,unsigned long event,void * ptr)1207 nfqnl_rcv_nl_event(struct notifier_block *this,
1208 unsigned long event, void *ptr)
1209 {
1210 struct netlink_notify *n = ptr;
1211 struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
1212
1213 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
1214 int i;
1215
1216 /* destroy all instances for this portid */
1217 spin_lock(&q->instances_lock);
1218 for (i = 0; i < INSTANCE_BUCKETS; i++) {
1219 struct hlist_node *t2;
1220 struct nfqnl_instance *inst;
1221 struct hlist_head *head = &q->instance_table[i];
1222
1223 hlist_for_each_entry_safe(inst, t2, head, hlist) {
1224 if (n->portid == inst->peer_portid)
1225 __instance_destroy(inst);
1226 }
1227 }
1228 spin_unlock(&q->instances_lock);
1229 }
1230 return NOTIFY_DONE;
1231 }
1232
1233 static struct notifier_block nfqnl_rtnl_notifier = {
1234 .notifier_call = nfqnl_rcv_nl_event,
1235 };
1236
1237 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
1238 [NFQA_VLAN_TCI] = { .type = NLA_U16},
1239 [NFQA_VLAN_PROTO] = { .type = NLA_U16},
1240 };
1241
1242 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
1243 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1244 [NFQA_MARK] = { .type = NLA_U32 },
1245 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC },
1246 [NFQA_CT] = { .type = NLA_UNSPEC },
1247 [NFQA_EXP] = { .type = NLA_UNSPEC },
1248 [NFQA_VLAN] = { .type = NLA_NESTED },
1249 [NFQA_PRIORITY] = { .type = NLA_U32 },
1250 };
1251
1252 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
1253 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1254 [NFQA_MARK] = { .type = NLA_U32 },
1255 [NFQA_PRIORITY] = { .type = NLA_U32 },
1256 };
1257
1258 static struct nfqnl_instance *
verdict_instance_lookup(struct nfnl_queue_net * q,u16 queue_num,u32 nlportid)1259 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
1260 {
1261 struct nfqnl_instance *queue;
1262
1263 queue = instance_lookup(q, queue_num);
1264 if (!queue)
1265 return ERR_PTR(-ENODEV);
1266
1267 if (queue->peer_portid != nlportid)
1268 return ERR_PTR(-EPERM);
1269
1270 return queue;
1271 }
1272
1273 static struct nfqnl_msg_verdict_hdr*
verdicthdr_get(const struct nlattr * const nfqa[])1274 verdicthdr_get(const struct nlattr * const nfqa[])
1275 {
1276 struct nfqnl_msg_verdict_hdr *vhdr;
1277 unsigned int verdict;
1278
1279 if (!nfqa[NFQA_VERDICT_HDR])
1280 return NULL;
1281
1282 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
1283 verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
1284 if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
1285 return NULL;
1286 return vhdr;
1287 }
1288
nfq_id_after(unsigned int id,unsigned int max)1289 static int nfq_id_after(unsigned int id, unsigned int max)
1290 {
1291 return (int)(id - max) > 0;
1292 }
1293
nfqnl_recv_verdict_batch(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1294 static int nfqnl_recv_verdict_batch(struct sk_buff *skb,
1295 const struct nfnl_info *info,
1296 const struct nlattr * const nfqa[])
1297 {
1298 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1299 u16 queue_num = ntohs(info->nfmsg->res_id);
1300 struct nf_queue_entry *entry, *tmp;
1301 struct nfqnl_msg_verdict_hdr *vhdr;
1302 struct nfqnl_instance *queue;
1303 unsigned int verdict, maxid;
1304 LIST_HEAD(batch_list);
1305
1306 queue = verdict_instance_lookup(q, queue_num,
1307 NETLINK_CB(skb).portid);
1308 if (IS_ERR(queue))
1309 return PTR_ERR(queue);
1310
1311 vhdr = verdicthdr_get(nfqa);
1312 if (!vhdr)
1313 return -EINVAL;
1314
1315 verdict = ntohl(vhdr->verdict);
1316 maxid = ntohl(vhdr->id);
1317
1318 spin_lock_bh(&queue->lock);
1319
1320 list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
1321 if (nfq_id_after(entry->id, maxid))
1322 break;
1323 __dequeue_entry(queue, entry);
1324 list_add_tail(&entry->list, &batch_list);
1325 }
1326
1327 spin_unlock_bh(&queue->lock);
1328
1329 if (list_empty(&batch_list))
1330 return -ENOENT;
1331
1332 list_for_each_entry_safe(entry, tmp, &batch_list, list) {
1333 if (nfqa[NFQA_MARK])
1334 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1335
1336 if (nfqa[NFQA_PRIORITY])
1337 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1338
1339 nfqnl_reinject(entry, verdict);
1340 }
1341 return 0;
1342 }
1343
nfqnl_ct_parse(const 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)1344 static struct nf_conn *nfqnl_ct_parse(const struct nfnl_ct_hook *nfnl_ct,
1345 const struct nlmsghdr *nlh,
1346 const struct nlattr * const nfqa[],
1347 struct nf_queue_entry *entry,
1348 enum ip_conntrack_info *ctinfo)
1349 {
1350 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
1351 struct nf_conn *ct;
1352
1353 ct = nf_ct_get(entry->skb, ctinfo);
1354 if (ct == NULL)
1355 return NULL;
1356
1357 if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
1358 return NULL;
1359
1360 if (nfqa[NFQA_EXP])
1361 nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
1362 NETLINK_CB(entry->skb).portid,
1363 nlmsg_report(nlh));
1364 return ct;
1365 #else
1366 return NULL;
1367 #endif
1368 }
1369
nfqa_parse_bridge(struct nf_queue_entry * entry,const struct nlattr * const nfqa[])1370 static int nfqa_parse_bridge(struct nf_queue_entry *entry,
1371 const struct nlattr * const nfqa[])
1372 {
1373 if (nfqa[NFQA_VLAN]) {
1374 struct nlattr *tb[NFQA_VLAN_MAX + 1];
1375 int err;
1376
1377 err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX,
1378 nfqa[NFQA_VLAN],
1379 nfqa_vlan_policy, NULL);
1380 if (err < 0)
1381 return err;
1382
1383 if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
1384 return -EINVAL;
1385
1386 __vlan_hwaccel_put_tag(entry->skb,
1387 nla_get_be16(tb[NFQA_VLAN_PROTO]),
1388 ntohs(nla_get_be16(tb[NFQA_VLAN_TCI])));
1389 }
1390
1391 if (nfqa[NFQA_L2HDR]) {
1392 int mac_header_len = entry->skb->network_header -
1393 entry->skb->mac_header;
1394
1395 if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
1396 return -EINVAL;
1397 else if (mac_header_len > 0)
1398 memcpy(skb_mac_header(entry->skb),
1399 nla_data(nfqa[NFQA_L2HDR]),
1400 mac_header_len);
1401 }
1402
1403 return 0;
1404 }
1405
nfqnl_recv_verdict(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1406 static int nfqnl_recv_verdict(struct sk_buff *skb, const struct nfnl_info *info,
1407 const struct nlattr * const nfqa[])
1408 {
1409 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1410 u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1411 const struct nfnl_ct_hook *nfnl_ct;
1412 struct nfqnl_msg_verdict_hdr *vhdr;
1413 enum ip_conntrack_info ctinfo;
1414 struct nfqnl_instance *queue;
1415 struct nf_queue_entry *entry;
1416 struct nf_conn *ct = NULL;
1417 unsigned int verdict;
1418 int err;
1419
1420 queue = verdict_instance_lookup(q, queue_num,
1421 NETLINK_CB(skb).portid);
1422 if (IS_ERR(queue))
1423 return PTR_ERR(queue);
1424
1425 vhdr = verdicthdr_get(nfqa);
1426 if (!vhdr)
1427 return -EINVAL;
1428
1429 verdict = ntohl(vhdr->verdict);
1430
1431 entry = find_dequeue_entry(queue, ntohl(vhdr->id));
1432 if (entry == NULL)
1433 return -ENOENT;
1434
1435 /* rcu lock already held from nfnl->call_rcu. */
1436 nfnl_ct = rcu_dereference(nfnl_ct_hook);
1437
1438 if (nfqa[NFQA_CT]) {
1439 if (nfnl_ct != NULL)
1440 ct = nfqnl_ct_parse(nfnl_ct, info->nlh, nfqa, entry,
1441 &ctinfo);
1442 }
1443
1444 if (entry->state.pf == PF_BRIDGE) {
1445 err = nfqa_parse_bridge(entry, nfqa);
1446 if (err < 0)
1447 return err;
1448 }
1449
1450 if (nfqa[NFQA_PAYLOAD]) {
1451 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
1452 int diff = payload_len - entry->skb->len;
1453
1454 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
1455 payload_len, entry, diff) < 0)
1456 verdict = NF_DROP;
1457
1458 if (ct && diff)
1459 nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
1460 }
1461
1462 if (nfqa[NFQA_MARK])
1463 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1464
1465 if (nfqa[NFQA_PRIORITY])
1466 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1467
1468 nfqnl_reinject(entry, verdict);
1469 return 0;
1470 }
1471
nfqnl_recv_unsupp(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const cda[])1472 static int nfqnl_recv_unsupp(struct sk_buff *skb, const struct nfnl_info *info,
1473 const struct nlattr * const cda[])
1474 {
1475 return -ENOTSUPP;
1476 }
1477
1478 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
1479 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
1480 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
1481 [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 },
1482 [NFQA_CFG_MASK] = { .type = NLA_U32 },
1483 [NFQA_CFG_FLAGS] = { .type = NLA_U32 },
1484 };
1485
1486 static const struct nf_queue_handler nfqh = {
1487 .outfn = nfqnl_enqueue_packet,
1488 .nf_hook_drop = nfqnl_nf_hook_drop,
1489 };
1490
nfqnl_recv_config(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1491 static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info,
1492 const struct nlattr * const nfqa[])
1493 {
1494 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1495 u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1496 struct nfqnl_msg_config_cmd *cmd = NULL;
1497 struct nfqnl_instance *queue;
1498 __u32 flags = 0, mask = 0;
1499 int ret = 0;
1500
1501 if (nfqa[NFQA_CFG_CMD]) {
1502 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1503
1504 /* Obsolete commands without queue context */
1505 switch (cmd->command) {
1506 case NFQNL_CFG_CMD_PF_BIND: return 0;
1507 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1508 }
1509 }
1510
1511 /* Check if we support these flags in first place, dependencies should
1512 * be there too not to break atomicity.
1513 */
1514 if (nfqa[NFQA_CFG_FLAGS]) {
1515 if (!nfqa[NFQA_CFG_MASK]) {
1516 /* A mask is needed to specify which flags are being
1517 * changed.
1518 */
1519 return -EINVAL;
1520 }
1521
1522 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1523 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1524
1525 if (flags >= NFQA_CFG_F_MAX)
1526 return -EOPNOTSUPP;
1527
1528 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
1529 if (flags & mask & NFQA_CFG_F_SECCTX)
1530 return -EOPNOTSUPP;
1531 #endif
1532 if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
1533 !rcu_access_pointer(nfnl_ct_hook)) {
1534 #ifdef CONFIG_MODULES
1535 nfnl_unlock(NFNL_SUBSYS_QUEUE);
1536 request_module("ip_conntrack_netlink");
1537 nfnl_lock(NFNL_SUBSYS_QUEUE);
1538 if (rcu_access_pointer(nfnl_ct_hook))
1539 return -EAGAIN;
1540 #endif
1541 return -EOPNOTSUPP;
1542 }
1543 }
1544
1545 rcu_read_lock();
1546 queue = instance_lookup(q, queue_num);
1547 if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1548 ret = -EPERM;
1549 goto err_out_unlock;
1550 }
1551
1552 if (cmd != NULL) {
1553 switch (cmd->command) {
1554 case NFQNL_CFG_CMD_BIND:
1555 if (queue) {
1556 ret = -EBUSY;
1557 goto err_out_unlock;
1558 }
1559 queue = instance_create(q, queue_num,
1560 NETLINK_CB(skb).portid);
1561 if (IS_ERR(queue)) {
1562 ret = PTR_ERR(queue);
1563 goto err_out_unlock;
1564 }
1565 break;
1566 case NFQNL_CFG_CMD_UNBIND:
1567 if (!queue) {
1568 ret = -ENODEV;
1569 goto err_out_unlock;
1570 }
1571 instance_destroy(q, queue);
1572 goto err_out_unlock;
1573 case NFQNL_CFG_CMD_PF_BIND:
1574 case NFQNL_CFG_CMD_PF_UNBIND:
1575 break;
1576 default:
1577 ret = -ENOTSUPP;
1578 goto err_out_unlock;
1579 }
1580 }
1581
1582 if (!queue) {
1583 ret = -ENODEV;
1584 goto err_out_unlock;
1585 }
1586
1587 if (nfqa[NFQA_CFG_PARAMS]) {
1588 struct nfqnl_msg_config_params *params =
1589 nla_data(nfqa[NFQA_CFG_PARAMS]);
1590
1591 nfqnl_set_mode(queue, params->copy_mode,
1592 ntohl(params->copy_range));
1593 }
1594
1595 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1596 __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1597
1598 spin_lock_bh(&queue->lock);
1599 queue->queue_maxlen = ntohl(*queue_maxlen);
1600 spin_unlock_bh(&queue->lock);
1601 }
1602
1603 if (nfqa[NFQA_CFG_FLAGS]) {
1604 spin_lock_bh(&queue->lock);
1605 queue->flags &= ~mask;
1606 queue->flags |= flags & mask;
1607 spin_unlock_bh(&queue->lock);
1608 }
1609
1610 err_out_unlock:
1611 rcu_read_unlock();
1612 return ret;
1613 }
1614
1615 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1616 [NFQNL_MSG_PACKET] = {
1617 .call = nfqnl_recv_unsupp,
1618 .type = NFNL_CB_RCU,
1619 .attr_count = NFQA_MAX,
1620 },
1621 [NFQNL_MSG_VERDICT] = {
1622 .call = nfqnl_recv_verdict,
1623 .type = NFNL_CB_RCU,
1624 .attr_count = NFQA_MAX,
1625 .policy = nfqa_verdict_policy
1626 },
1627 [NFQNL_MSG_CONFIG] = {
1628 .call = nfqnl_recv_config,
1629 .type = NFNL_CB_MUTEX,
1630 .attr_count = NFQA_CFG_MAX,
1631 .policy = nfqa_cfg_policy
1632 },
1633 [NFQNL_MSG_VERDICT_BATCH] = {
1634 .call = nfqnl_recv_verdict_batch,
1635 .type = NFNL_CB_RCU,
1636 .attr_count = NFQA_MAX,
1637 .policy = nfqa_verdict_batch_policy
1638 },
1639 };
1640
1641 static const struct nfnetlink_subsystem nfqnl_subsys = {
1642 .name = "nf_queue",
1643 .subsys_id = NFNL_SUBSYS_QUEUE,
1644 .cb_count = NFQNL_MSG_MAX,
1645 .cb = nfqnl_cb,
1646 };
1647
1648 #ifdef CONFIG_PROC_FS
1649 struct iter_state {
1650 struct seq_net_private p;
1651 unsigned int bucket;
1652 };
1653
get_first(struct seq_file * seq)1654 static struct hlist_node *get_first(struct seq_file *seq)
1655 {
1656 struct iter_state *st = seq->private;
1657 struct net *net;
1658 struct nfnl_queue_net *q;
1659
1660 if (!st)
1661 return NULL;
1662
1663 net = seq_file_net(seq);
1664 q = nfnl_queue_pernet(net);
1665 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1666 if (!hlist_empty(&q->instance_table[st->bucket]))
1667 return q->instance_table[st->bucket].first;
1668 }
1669 return NULL;
1670 }
1671
get_next(struct seq_file * seq,struct hlist_node * h)1672 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1673 {
1674 struct iter_state *st = seq->private;
1675 struct net *net = seq_file_net(seq);
1676
1677 h = h->next;
1678 while (!h) {
1679 struct nfnl_queue_net *q;
1680
1681 if (++st->bucket >= INSTANCE_BUCKETS)
1682 return NULL;
1683
1684 q = nfnl_queue_pernet(net);
1685 h = q->instance_table[st->bucket].first;
1686 }
1687 return h;
1688 }
1689
get_idx(struct seq_file * seq,loff_t pos)1690 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1691 {
1692 struct hlist_node *head;
1693 head = get_first(seq);
1694
1695 if (head)
1696 while (pos && (head = get_next(seq, head)))
1697 pos--;
1698 return pos ? NULL : head;
1699 }
1700
seq_start(struct seq_file * s,loff_t * pos)1701 static void *seq_start(struct seq_file *s, loff_t *pos)
1702 __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1703 {
1704 spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1705 return get_idx(s, *pos);
1706 }
1707
seq_next(struct seq_file * s,void * v,loff_t * pos)1708 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1709 {
1710 (*pos)++;
1711 return get_next(s, v);
1712 }
1713
seq_stop(struct seq_file * s,void * v)1714 static void seq_stop(struct seq_file *s, void *v)
1715 __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1716 {
1717 spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1718 }
1719
seq_show(struct seq_file * s,void * v)1720 static int seq_show(struct seq_file *s, void *v)
1721 {
1722 const struct nfqnl_instance *inst = v;
1723
1724 seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
1725 inst->queue_num,
1726 inst->peer_portid, inst->queue_total,
1727 inst->copy_mode, inst->copy_range,
1728 inst->queue_dropped, inst->queue_user_dropped,
1729 inst->id_sequence, 1);
1730 return 0;
1731 }
1732
1733 static const struct seq_operations nfqnl_seq_ops = {
1734 .start = seq_start,
1735 .next = seq_next,
1736 .stop = seq_stop,
1737 .show = seq_show,
1738 };
1739 #endif /* PROC_FS */
1740
nfnl_queue_net_init(struct net * net)1741 static int __net_init nfnl_queue_net_init(struct net *net)
1742 {
1743 unsigned int i;
1744 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1745
1746 for (i = 0; i < INSTANCE_BUCKETS; i++)
1747 INIT_HLIST_HEAD(&q->instance_table[i]);
1748
1749 spin_lock_init(&q->instances_lock);
1750
1751 #ifdef CONFIG_PROC_FS
1752 if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter,
1753 &nfqnl_seq_ops, sizeof(struct iter_state)))
1754 return -ENOMEM;
1755 #endif
1756 return 0;
1757 }
1758
nfnl_queue_net_exit(struct net * net)1759 static void __net_exit nfnl_queue_net_exit(struct net *net)
1760 {
1761 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1762 unsigned int i;
1763
1764 #ifdef CONFIG_PROC_FS
1765 remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1766 #endif
1767 for (i = 0; i < INSTANCE_BUCKETS; i++)
1768 WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
1769 }
1770
1771 static struct pernet_operations nfnl_queue_net_ops = {
1772 .init = nfnl_queue_net_init,
1773 .exit = nfnl_queue_net_exit,
1774 .id = &nfnl_queue_net_id,
1775 .size = sizeof(struct nfnl_queue_net),
1776 };
1777
nfnetlink_queue_init(void)1778 static int __init nfnetlink_queue_init(void)
1779 {
1780 int status;
1781
1782 status = register_pernet_subsys(&nfnl_queue_net_ops);
1783 if (status < 0) {
1784 pr_err("failed to register pernet ops\n");
1785 goto out;
1786 }
1787
1788 netlink_register_notifier(&nfqnl_rtnl_notifier);
1789 status = nfnetlink_subsys_register(&nfqnl_subsys);
1790 if (status < 0) {
1791 pr_err("failed to create netlink socket\n");
1792 goto cleanup_netlink_notifier;
1793 }
1794
1795 status = register_netdevice_notifier(&nfqnl_dev_notifier);
1796 if (status < 0) {
1797 pr_err("failed to register netdevice notifier\n");
1798 goto cleanup_netlink_subsys;
1799 }
1800
1801 nf_register_queue_handler(&nfqh);
1802
1803 return status;
1804
1805 cleanup_netlink_subsys:
1806 nfnetlink_subsys_unregister(&nfqnl_subsys);
1807 cleanup_netlink_notifier:
1808 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1809 unregister_pernet_subsys(&nfnl_queue_net_ops);
1810 out:
1811 return status;
1812 }
1813
nfnetlink_queue_fini(void)1814 static void __exit nfnetlink_queue_fini(void)
1815 {
1816 nf_unregister_queue_handler();
1817 unregister_netdevice_notifier(&nfqnl_dev_notifier);
1818 nfnetlink_subsys_unregister(&nfqnl_subsys);
1819 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1820 unregister_pernet_subsys(&nfnl_queue_net_ops);
1821
1822 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1823 }
1824
1825 MODULE_DESCRIPTION("netfilter packet queue handler");
1826 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1827 MODULE_LICENSE("GPL");
1828 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1829
1830 module_init(nfnetlink_queue_init);
1831 module_exit(nfnetlink_queue_fini);
1832