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 nfqnl_flush(inst, NULL, 0);
173 kfree(inst);
174 module_put(THIS_MODULE);
175 }
176
177 static void
__instance_destroy(struct nfqnl_instance * inst)178 __instance_destroy(struct nfqnl_instance *inst)
179 {
180 hlist_del_rcu(&inst->hlist);
181 call_rcu(&inst->rcu, instance_destroy_rcu);
182 }
183
184 static void
instance_destroy(struct nfnl_queue_net * q,struct nfqnl_instance * inst)185 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
186 {
187 spin_lock(&q->instances_lock);
188 __instance_destroy(inst);
189 spin_unlock(&q->instances_lock);
190 }
191
192 static inline void
__enqueue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)193 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
194 {
195 list_add_tail(&entry->list, &queue->queue_list);
196 queue->queue_total++;
197 }
198
199 static void
__dequeue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)200 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
201 {
202 list_del(&entry->list);
203 queue->queue_total--;
204 }
205
206 static struct nf_queue_entry *
find_dequeue_entry(struct nfqnl_instance * queue,unsigned int id)207 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
208 {
209 struct nf_queue_entry *entry = NULL, *i;
210
211 spin_lock_bh(&queue->lock);
212
213 list_for_each_entry(i, &queue->queue_list, list) {
214 if (i->id == id) {
215 entry = i;
216 break;
217 }
218 }
219
220 if (entry)
221 __dequeue_entry(queue, entry);
222
223 spin_unlock_bh(&queue->lock);
224
225 return entry;
226 }
227
nfqnl_reinject(struct nf_queue_entry * entry,unsigned int verdict)228 static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict)
229 {
230 const struct nf_ct_hook *ct_hook;
231
232 if (verdict == NF_ACCEPT ||
233 verdict == NF_REPEAT ||
234 verdict == NF_STOP) {
235 unsigned int ct_verdict = verdict;
236
237 rcu_read_lock();
238 ct_hook = rcu_dereference(nf_ct_hook);
239 if (ct_hook)
240 ct_verdict = ct_hook->update(entry->state.net, entry->skb);
241 rcu_read_unlock();
242
243 switch (ct_verdict & NF_VERDICT_MASK) {
244 case NF_ACCEPT:
245 /* follow userspace verdict, could be REPEAT */
246 break;
247 case NF_STOLEN:
248 nf_queue_entry_free(entry);
249 return;
250 default:
251 verdict = ct_verdict & NF_VERDICT_MASK;
252 break;
253 }
254 }
255 nf_reinject(entry, verdict);
256 }
257
258 static void
nfqnl_flush(struct nfqnl_instance * queue,nfqnl_cmpfn cmpfn,unsigned long data)259 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
260 {
261 struct nf_queue_entry *entry, *next;
262
263 spin_lock_bh(&queue->lock);
264 list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
265 if (!cmpfn || cmpfn(entry, data)) {
266 list_del(&entry->list);
267 queue->queue_total--;
268 nfqnl_reinject(entry, NF_DROP);
269 }
270 }
271 spin_unlock_bh(&queue->lock);
272 }
273
274 static int
nfqnl_put_packet_info(struct sk_buff * nlskb,struct sk_buff * packet,bool csum_verify)275 nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet,
276 bool csum_verify)
277 {
278 __u32 flags = 0;
279
280 if (packet->ip_summed == CHECKSUM_PARTIAL)
281 flags = NFQA_SKB_CSUMNOTREADY;
282 else if (csum_verify)
283 flags = NFQA_SKB_CSUM_NOTVERIFIED;
284
285 if (skb_is_gso(packet))
286 flags |= NFQA_SKB_GSO;
287
288 return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0;
289 }
290
nfqnl_put_sk_uidgid(struct sk_buff * skb,struct sock * sk)291 static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
292 {
293 const struct cred *cred;
294
295 if (!sk_fullsock(sk))
296 return 0;
297
298 read_lock_bh(&sk->sk_callback_lock);
299 if (sk->sk_socket && sk->sk_socket->file) {
300 cred = sk->sk_socket->file->f_cred;
301 if (nla_put_be32(skb, NFQA_UID,
302 htonl(from_kuid_munged(&init_user_ns, cred->fsuid))))
303 goto nla_put_failure;
304 if (nla_put_be32(skb, NFQA_GID,
305 htonl(from_kgid_munged(&init_user_ns, cred->fsgid))))
306 goto nla_put_failure;
307 }
308 read_unlock_bh(&sk->sk_callback_lock);
309 return 0;
310
311 nla_put_failure:
312 read_unlock_bh(&sk->sk_callback_lock);
313 return -1;
314 }
315
nfqnl_put_sk_classid(struct sk_buff * skb,struct sock * sk)316 static int nfqnl_put_sk_classid(struct sk_buff *skb, struct sock *sk)
317 {
318 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
319 if (sk && sk_fullsock(sk)) {
320 u32 classid = sock_cgroup_classid(&sk->sk_cgrp_data);
321
322 if (classid && nla_put_be32(skb, NFQA_CGROUP_CLASSID, htonl(classid)))
323 return -1;
324 }
325 #endif
326 return 0;
327 }
328
nfqnl_get_sk_secctx(struct sk_buff * skb,char ** secdata)329 static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
330 {
331 u32 seclen = 0;
332 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
333 if (!skb || !sk_fullsock(skb->sk))
334 return 0;
335
336 read_lock_bh(&skb->sk->sk_callback_lock);
337
338 if (skb->secmark)
339 security_secid_to_secctx(skb->secmark, secdata, &seclen);
340
341 read_unlock_bh(&skb->sk->sk_callback_lock);
342 #endif
343 return seclen;
344 }
345
nfqnl_get_bridge_size(struct nf_queue_entry * entry)346 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
347 {
348 struct sk_buff *entskb = entry->skb;
349 u32 nlalen = 0;
350
351 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
352 return 0;
353
354 if (skb_vlan_tag_present(entskb))
355 nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
356 nla_total_size(sizeof(__be16)));
357
358 if (entskb->network_header > entskb->mac_header)
359 nlalen += nla_total_size((entskb->network_header -
360 entskb->mac_header));
361
362 return nlalen;
363 }
364
nfqnl_put_bridge(struct nf_queue_entry * entry,struct sk_buff * skb)365 static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
366 {
367 struct sk_buff *entskb = entry->skb;
368
369 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
370 return 0;
371
372 if (skb_vlan_tag_present(entskb)) {
373 struct nlattr *nest;
374
375 nest = nla_nest_start(skb, NFQA_VLAN);
376 if (!nest)
377 goto nla_put_failure;
378
379 if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
380 nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
381 goto nla_put_failure;
382
383 nla_nest_end(skb, nest);
384 }
385
386 if (entskb->mac_header < entskb->network_header) {
387 int len = (int)(entskb->network_header - entskb->mac_header);
388
389 if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb)))
390 goto nla_put_failure;
391 }
392
393 return 0;
394
395 nla_put_failure:
396 return -1;
397 }
398
399 static struct sk_buff *
nfqnl_build_packet_message(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry,__be32 ** packet_id_ptr)400 nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
401 struct nf_queue_entry *entry,
402 __be32 **packet_id_ptr)
403 {
404 size_t size;
405 size_t data_len = 0, cap_len = 0;
406 unsigned int hlen = 0;
407 struct sk_buff *skb;
408 struct nlattr *nla;
409 struct nfqnl_msg_packet_hdr *pmsg;
410 struct nlmsghdr *nlh;
411 struct sk_buff *entskb = entry->skb;
412 struct net_device *indev;
413 struct net_device *outdev;
414 struct nf_conn *ct = NULL;
415 enum ip_conntrack_info ctinfo = 0;
416 const struct nfnl_ct_hook *nfnl_ct;
417 bool csum_verify;
418 char *secdata = NULL;
419 u32 seclen = 0;
420 ktime_t tstamp;
421
422 size = nlmsg_total_size(sizeof(struct nfgenmsg))
423 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
424 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
425 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
426 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
427 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
428 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
429 #endif
430 + nla_total_size(sizeof(u_int32_t)) /* mark */
431 + nla_total_size(sizeof(u_int32_t)) /* priority */
432 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
433 + nla_total_size(sizeof(u_int32_t)) /* skbinfo */
434 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
435 + nla_total_size(sizeof(u_int32_t)) /* classid */
436 #endif
437 + nla_total_size(sizeof(u_int32_t)); /* cap_len */
438
439 tstamp = skb_tstamp_cond(entskb, false);
440 if (tstamp)
441 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
442
443 size += nfqnl_get_bridge_size(entry);
444
445 if (entry->state.hook <= NF_INET_FORWARD ||
446 (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
447 csum_verify = !skb_csum_unnecessary(entskb);
448 else
449 csum_verify = false;
450
451 outdev = entry->state.out;
452
453 switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) {
454 case NFQNL_COPY_META:
455 case NFQNL_COPY_NONE:
456 break;
457
458 case NFQNL_COPY_PACKET:
459 if (!(queue->flags & NFQA_CFG_F_GSO) &&
460 entskb->ip_summed == CHECKSUM_PARTIAL &&
461 skb_checksum_help(entskb))
462 return NULL;
463
464 data_len = READ_ONCE(queue->copy_range);
465 if (data_len > entskb->len)
466 data_len = entskb->len;
467
468 hlen = skb_zerocopy_headlen(entskb);
469 hlen = min_t(unsigned int, hlen, data_len);
470 size += sizeof(struct nlattr) + hlen;
471 cap_len = entskb->len;
472 break;
473 }
474
475 nfnl_ct = rcu_dereference(nfnl_ct_hook);
476
477 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
478 if (queue->flags & NFQA_CFG_F_CONNTRACK) {
479 if (nfnl_ct != NULL) {
480 ct = nf_ct_get(entskb, &ctinfo);
481 if (ct != NULL)
482 size += nfnl_ct->build_size(ct);
483 }
484 }
485 #endif
486
487 if (queue->flags & NFQA_CFG_F_UID_GID) {
488 size += (nla_total_size(sizeof(u_int32_t)) /* uid */
489 + nla_total_size(sizeof(u_int32_t))); /* gid */
490 }
491
492 if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
493 seclen = nfqnl_get_sk_secctx(entskb, &secdata);
494 if (seclen)
495 size += nla_total_size(seclen);
496 }
497
498 skb = alloc_skb(size, GFP_ATOMIC);
499 if (!skb) {
500 skb_tx_error(entskb);
501 goto nlmsg_failure;
502 }
503
504 nlh = nfnl_msg_put(skb, 0, 0,
505 nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET),
506 0, entry->state.pf, NFNETLINK_V0,
507 htons(queue->queue_num));
508 if (!nlh) {
509 skb_tx_error(entskb);
510 kfree_skb(skb);
511 goto nlmsg_failure;
512 }
513
514 nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
515 pmsg = nla_data(nla);
516 pmsg->hw_protocol = entskb->protocol;
517 pmsg->hook = entry->state.hook;
518 *packet_id_ptr = &pmsg->packet_id;
519
520 indev = entry->state.in;
521 if (indev) {
522 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
523 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
524 goto nla_put_failure;
525 #else
526 if (entry->state.pf == PF_BRIDGE) {
527 /* Case 1: indev is physical input device, we need to
528 * look for bridge group (when called from
529 * netfilter_bridge) */
530 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
531 htonl(indev->ifindex)) ||
532 /* this is the bridge group "brX" */
533 /* rcu_read_lock()ed by __nf_queue */
534 nla_put_be32(skb, NFQA_IFINDEX_INDEV,
535 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
536 goto nla_put_failure;
537 } else {
538 int physinif;
539
540 /* Case 2: indev is bridge group, we need to look for
541 * physical device (when called from ipv4) */
542 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
543 htonl(indev->ifindex)))
544 goto nla_put_failure;
545
546 physinif = nf_bridge_get_physinif(entskb);
547 if (physinif &&
548 nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
549 htonl(physinif)))
550 goto nla_put_failure;
551 }
552 #endif
553 }
554
555 if (outdev) {
556 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
557 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
558 goto nla_put_failure;
559 #else
560 if (entry->state.pf == PF_BRIDGE) {
561 /* Case 1: outdev is physical output device, we need to
562 * look for bridge group (when called from
563 * netfilter_bridge) */
564 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
565 htonl(outdev->ifindex)) ||
566 /* this is the bridge group "brX" */
567 /* rcu_read_lock()ed by __nf_queue */
568 nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
569 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
570 goto nla_put_failure;
571 } else {
572 int physoutif;
573
574 /* Case 2: outdev is bridge group, we need to look for
575 * physical output device (when called from ipv4) */
576 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
577 htonl(outdev->ifindex)))
578 goto nla_put_failure;
579
580 physoutif = nf_bridge_get_physoutif(entskb);
581 if (physoutif &&
582 nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
583 htonl(physoutif)))
584 goto nla_put_failure;
585 }
586 #endif
587 }
588
589 if (entskb->mark &&
590 nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
591 goto nla_put_failure;
592
593 if (entskb->priority &&
594 nla_put_be32(skb, NFQA_PRIORITY, htonl(entskb->priority)))
595 goto nla_put_failure;
596
597 if (indev && entskb->dev &&
598 skb_mac_header_was_set(entskb) &&
599 skb_mac_header_len(entskb) != 0) {
600 struct nfqnl_msg_packet_hw phw;
601 int len;
602
603 memset(&phw, 0, sizeof(phw));
604 len = dev_parse_header(entskb, phw.hw_addr);
605 if (len) {
606 phw.hw_addrlen = htons(len);
607 if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
608 goto nla_put_failure;
609 }
610 }
611
612 if (nfqnl_put_bridge(entry, skb) < 0)
613 goto nla_put_failure;
614
615 if (entry->state.hook <= NF_INET_FORWARD && tstamp) {
616 struct nfqnl_msg_packet_timestamp ts;
617 struct timespec64 kts = ktime_to_timespec64(tstamp);
618
619 ts.sec = cpu_to_be64(kts.tv_sec);
620 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
621
622 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
623 goto nla_put_failure;
624 }
625
626 if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
627 nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
628 goto nla_put_failure;
629
630 if (nfqnl_put_sk_classid(skb, entskb->sk) < 0)
631 goto nla_put_failure;
632
633 if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
634 goto nla_put_failure;
635
636 if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
637 goto nla_put_failure;
638
639 if (cap_len > data_len &&
640 nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
641 goto nla_put_failure;
642
643 if (nfqnl_put_packet_info(skb, entskb, csum_verify))
644 goto nla_put_failure;
645
646 if (data_len) {
647 struct nlattr *nla;
648
649 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
650 goto nla_put_failure;
651
652 nla = skb_put(skb, sizeof(*nla));
653 nla->nla_type = NFQA_PAYLOAD;
654 nla->nla_len = nla_attr_size(data_len);
655
656 if (skb_zerocopy(skb, entskb, data_len, hlen))
657 goto nla_put_failure;
658 }
659
660 nlh->nlmsg_len = skb->len;
661 if (seclen)
662 security_release_secctx(secdata, seclen);
663 return skb;
664
665 nla_put_failure:
666 skb_tx_error(entskb);
667 kfree_skb(skb);
668 net_err_ratelimited("nf_queue: error creating packet message\n");
669 nlmsg_failure:
670 if (seclen)
671 security_release_secctx(secdata, seclen);
672 return NULL;
673 }
674
nf_ct_drop_unconfirmed(const struct nf_queue_entry * entry)675 static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry)
676 {
677 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
678 static const unsigned long flags = IPS_CONFIRMED | IPS_DYING;
679 const struct nf_conn *ct = (void *)skb_nfct(entry->skb);
680
681 if (ct && ((ct->status & flags) == IPS_DYING))
682 return true;
683 #endif
684 return false;
685 }
686
687 static int
__nfqnl_enqueue_packet(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry)688 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
689 struct nf_queue_entry *entry)
690 {
691 struct sk_buff *nskb;
692 int err = -ENOBUFS;
693 __be32 *packet_id_ptr;
694 int failopen = 0;
695
696 nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
697 if (nskb == NULL) {
698 err = -ENOMEM;
699 goto err_out;
700 }
701 spin_lock_bh(&queue->lock);
702
703 if (nf_ct_drop_unconfirmed(entry))
704 goto err_out_free_nskb;
705
706 if (queue->queue_total >= queue->queue_maxlen) {
707 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
708 failopen = 1;
709 err = 0;
710 } else {
711 queue->queue_dropped++;
712 net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
713 queue->queue_total);
714 }
715 goto err_out_free_nskb;
716 }
717 entry->id = ++queue->id_sequence;
718 *packet_id_ptr = htonl(entry->id);
719
720 /* nfnetlink_unicast will either free the nskb or add it to a socket */
721 err = nfnetlink_unicast(nskb, net, queue->peer_portid);
722 if (err < 0) {
723 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
724 failopen = 1;
725 err = 0;
726 } else {
727 queue->queue_user_dropped++;
728 }
729 goto err_out_unlock;
730 }
731
732 __enqueue_entry(queue, entry);
733
734 spin_unlock_bh(&queue->lock);
735 return 0;
736
737 err_out_free_nskb:
738 kfree_skb(nskb);
739 err_out_unlock:
740 spin_unlock_bh(&queue->lock);
741 if (failopen)
742 nfqnl_reinject(entry, NF_ACCEPT);
743 err_out:
744 return err;
745 }
746
747 static struct nf_queue_entry *
nf_queue_entry_dup(struct nf_queue_entry * e)748 nf_queue_entry_dup(struct nf_queue_entry *e)
749 {
750 struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
751
752 if (!entry)
753 return NULL;
754
755 if (nf_queue_entry_get_refs(entry))
756 return entry;
757
758 kfree(entry);
759 return NULL;
760 }
761
762 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
763 /* When called from bridge netfilter, skb->data must point to MAC header
764 * before calling skb_gso_segment(). Else, original MAC header is lost
765 * and segmented skbs will be sent to wrong destination.
766 */
nf_bridge_adjust_skb_data(struct sk_buff * skb)767 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
768 {
769 if (nf_bridge_info_get(skb))
770 __skb_push(skb, skb->network_header - skb->mac_header);
771 }
772
nf_bridge_adjust_segmented_data(struct sk_buff * skb)773 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
774 {
775 if (nf_bridge_info_get(skb))
776 __skb_pull(skb, skb->network_header - skb->mac_header);
777 }
778 #else
779 #define nf_bridge_adjust_skb_data(s) do {} while (0)
780 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
781 #endif
782
783 static int
__nfqnl_enqueue_packet_gso(struct net * net,struct nfqnl_instance * queue,struct sk_buff * skb,struct nf_queue_entry * entry)784 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
785 struct sk_buff *skb, struct nf_queue_entry *entry)
786 {
787 int ret = -ENOMEM;
788 struct nf_queue_entry *entry_seg;
789
790 nf_bridge_adjust_segmented_data(skb);
791
792 if (skb->next == NULL) { /* last packet, no need to copy entry */
793 struct sk_buff *gso_skb = entry->skb;
794 entry->skb = skb;
795 ret = __nfqnl_enqueue_packet(net, queue, entry);
796 if (ret)
797 entry->skb = gso_skb;
798 return ret;
799 }
800
801 skb_mark_not_on_list(skb);
802
803 entry_seg = nf_queue_entry_dup(entry);
804 if (entry_seg) {
805 entry_seg->skb = skb;
806 ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
807 if (ret)
808 nf_queue_entry_free(entry_seg);
809 }
810 return ret;
811 }
812
813 static int
nfqnl_enqueue_packet(struct nf_queue_entry * entry,unsigned int queuenum)814 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
815 {
816 unsigned int queued;
817 struct nfqnl_instance *queue;
818 struct sk_buff *skb, *segs, *nskb;
819 int err = -ENOBUFS;
820 struct net *net = entry->state.net;
821 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
822
823 /* rcu_read_lock()ed by nf_hook_thresh */
824 queue = instance_lookup(q, queuenum);
825 if (!queue)
826 return -ESRCH;
827
828 if (queue->copy_mode == NFQNL_COPY_NONE)
829 return -EINVAL;
830
831 skb = entry->skb;
832
833 switch (entry->state.pf) {
834 case NFPROTO_IPV4:
835 skb->protocol = htons(ETH_P_IP);
836 break;
837 case NFPROTO_IPV6:
838 skb->protocol = htons(ETH_P_IPV6);
839 break;
840 }
841
842 if ((queue->flags & NFQA_CFG_F_GSO) || !skb_is_gso(skb))
843 return __nfqnl_enqueue_packet(net, queue, entry);
844
845 nf_bridge_adjust_skb_data(skb);
846 segs = skb_gso_segment(skb, 0);
847 /* Does not use PTR_ERR to limit the number of error codes that can be
848 * returned by nf_queue. For instance, callers rely on -ESRCH to
849 * mean 'ignore this hook'.
850 */
851 if (IS_ERR_OR_NULL(segs))
852 goto out_err;
853 queued = 0;
854 err = 0;
855 skb_list_walk_safe(segs, segs, nskb) {
856 if (err == 0)
857 err = __nfqnl_enqueue_packet_gso(net, queue,
858 segs, entry);
859 if (err == 0)
860 queued++;
861 else
862 kfree_skb(segs);
863 }
864
865 if (queued) {
866 if (err) /* some segments are already queued */
867 nf_queue_entry_free(entry);
868 kfree_skb(skb);
869 return 0;
870 }
871 out_err:
872 nf_bridge_adjust_segmented_data(skb);
873 return err;
874 }
875
876 static int
nfqnl_mangle(void * data,unsigned int data_len,struct nf_queue_entry * e,int diff)877 nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff)
878 {
879 struct sk_buff *nskb;
880
881 if (diff < 0) {
882 unsigned int min_len = skb_transport_offset(e->skb);
883
884 if (data_len < min_len)
885 return -EINVAL;
886
887 if (pskb_trim(e->skb, data_len))
888 return -ENOMEM;
889 } else if (diff > 0) {
890 if (data_len > 0xFFFF)
891 return -EINVAL;
892 if (diff > skb_tailroom(e->skb)) {
893 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
894 diff, GFP_ATOMIC);
895 if (!nskb)
896 return -ENOMEM;
897 kfree_skb(e->skb);
898 e->skb = nskb;
899 }
900 skb_put(e->skb, diff);
901 }
902 if (skb_ensure_writable(e->skb, data_len))
903 return -ENOMEM;
904 skb_copy_to_linear_data(e->skb, data, data_len);
905 e->skb->ip_summed = CHECKSUM_NONE;
906 return 0;
907 }
908
909 static int
nfqnl_set_mode(struct nfqnl_instance * queue,unsigned char mode,unsigned int range)910 nfqnl_set_mode(struct nfqnl_instance *queue,
911 unsigned char mode, unsigned int range)
912 {
913 int status = 0;
914
915 spin_lock_bh(&queue->lock);
916 switch (mode) {
917 case NFQNL_COPY_NONE:
918 case NFQNL_COPY_META:
919 queue->copy_mode = mode;
920 queue->copy_range = 0;
921 break;
922
923 case NFQNL_COPY_PACKET:
924 queue->copy_mode = mode;
925 if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
926 queue->copy_range = NFQNL_MAX_COPY_RANGE;
927 else
928 queue->copy_range = range;
929 break;
930
931 default:
932 status = -EINVAL;
933
934 }
935 spin_unlock_bh(&queue->lock);
936
937 return status;
938 }
939
940 static int
dev_cmp(struct nf_queue_entry * entry,unsigned long ifindex)941 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
942 {
943 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
944 int physinif, physoutif;
945
946 physinif = nf_bridge_get_physinif(entry->skb);
947 physoutif = nf_bridge_get_physoutif(entry->skb);
948
949 if (physinif == ifindex || physoutif == ifindex)
950 return 1;
951 #endif
952 if (entry->state.in)
953 if (entry->state.in->ifindex == ifindex)
954 return 1;
955 if (entry->state.out)
956 if (entry->state.out->ifindex == ifindex)
957 return 1;
958
959 return 0;
960 }
961
962 /* drop all packets with either indev or outdev == ifindex from all queue
963 * instances */
964 static void
nfqnl_dev_drop(struct net * net,int ifindex)965 nfqnl_dev_drop(struct net *net, int ifindex)
966 {
967 int i;
968 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
969
970 rcu_read_lock();
971
972 for (i = 0; i < INSTANCE_BUCKETS; i++) {
973 struct nfqnl_instance *inst;
974 struct hlist_head *head = &q->instance_table[i];
975
976 hlist_for_each_entry_rcu(inst, head, hlist)
977 nfqnl_flush(inst, dev_cmp, ifindex);
978 }
979
980 rcu_read_unlock();
981 }
982
983 static int
nfqnl_rcv_dev_event(struct notifier_block * this,unsigned long event,void * ptr)984 nfqnl_rcv_dev_event(struct notifier_block *this,
985 unsigned long event, void *ptr)
986 {
987 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
988
989 /* Drop any packets associated with the downed device */
990 if (event == NETDEV_DOWN)
991 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
992 return NOTIFY_DONE;
993 }
994
995 static struct notifier_block nfqnl_dev_notifier = {
996 .notifier_call = nfqnl_rcv_dev_event,
997 };
998
nfqnl_nf_hook_drop(struct net * net)999 static void nfqnl_nf_hook_drop(struct net *net)
1000 {
1001 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1002 int i;
1003
1004 /* This function is also called on net namespace error unwind,
1005 * when pernet_ops->init() failed and ->exit() functions of the
1006 * previous pernet_ops gets called.
1007 *
1008 * This may result in a call to nfqnl_nf_hook_drop() before
1009 * struct nfnl_queue_net was allocated.
1010 */
1011 if (!q)
1012 return;
1013
1014 for (i = 0; i < INSTANCE_BUCKETS; i++) {
1015 struct nfqnl_instance *inst;
1016 struct hlist_head *head = &q->instance_table[i];
1017
1018 hlist_for_each_entry_rcu(inst, head, hlist)
1019 nfqnl_flush(inst, NULL, 0);
1020 }
1021 }
1022
1023 static int
nfqnl_rcv_nl_event(struct notifier_block * this,unsigned long event,void * ptr)1024 nfqnl_rcv_nl_event(struct notifier_block *this,
1025 unsigned long event, void *ptr)
1026 {
1027 struct netlink_notify *n = ptr;
1028 struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
1029
1030 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
1031 int i;
1032
1033 /* destroy all instances for this portid */
1034 spin_lock(&q->instances_lock);
1035 for (i = 0; i < INSTANCE_BUCKETS; i++) {
1036 struct hlist_node *t2;
1037 struct nfqnl_instance *inst;
1038 struct hlist_head *head = &q->instance_table[i];
1039
1040 hlist_for_each_entry_safe(inst, t2, head, hlist) {
1041 if (n->portid == inst->peer_portid)
1042 __instance_destroy(inst);
1043 }
1044 }
1045 spin_unlock(&q->instances_lock);
1046 }
1047 return NOTIFY_DONE;
1048 }
1049
1050 static struct notifier_block nfqnl_rtnl_notifier = {
1051 .notifier_call = nfqnl_rcv_nl_event,
1052 };
1053
1054 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
1055 [NFQA_VLAN_TCI] = { .type = NLA_U16},
1056 [NFQA_VLAN_PROTO] = { .type = NLA_U16},
1057 };
1058
1059 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
1060 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1061 [NFQA_MARK] = { .type = NLA_U32 },
1062 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC },
1063 [NFQA_CT] = { .type = NLA_UNSPEC },
1064 [NFQA_EXP] = { .type = NLA_UNSPEC },
1065 [NFQA_VLAN] = { .type = NLA_NESTED },
1066 [NFQA_PRIORITY] = { .type = NLA_U32 },
1067 };
1068
1069 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
1070 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1071 [NFQA_MARK] = { .type = NLA_U32 },
1072 [NFQA_PRIORITY] = { .type = NLA_U32 },
1073 };
1074
1075 static struct nfqnl_instance *
verdict_instance_lookup(struct nfnl_queue_net * q,u16 queue_num,u32 nlportid)1076 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
1077 {
1078 struct nfqnl_instance *queue;
1079
1080 queue = instance_lookup(q, queue_num);
1081 if (!queue)
1082 return ERR_PTR(-ENODEV);
1083
1084 if (queue->peer_portid != nlportid)
1085 return ERR_PTR(-EPERM);
1086
1087 return queue;
1088 }
1089
1090 static struct nfqnl_msg_verdict_hdr*
verdicthdr_get(const struct nlattr * const nfqa[])1091 verdicthdr_get(const struct nlattr * const nfqa[])
1092 {
1093 struct nfqnl_msg_verdict_hdr *vhdr;
1094 unsigned int verdict;
1095
1096 if (!nfqa[NFQA_VERDICT_HDR])
1097 return NULL;
1098
1099 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
1100 verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
1101 if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
1102 return NULL;
1103 return vhdr;
1104 }
1105
nfq_id_after(unsigned int id,unsigned int max)1106 static int nfq_id_after(unsigned int id, unsigned int max)
1107 {
1108 return (int)(id - max) > 0;
1109 }
1110
nfqnl_recv_verdict_batch(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1111 static int nfqnl_recv_verdict_batch(struct sk_buff *skb,
1112 const struct nfnl_info *info,
1113 const struct nlattr * const nfqa[])
1114 {
1115 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1116 u16 queue_num = ntohs(info->nfmsg->res_id);
1117 struct nf_queue_entry *entry, *tmp;
1118 struct nfqnl_msg_verdict_hdr *vhdr;
1119 struct nfqnl_instance *queue;
1120 unsigned int verdict, maxid;
1121 LIST_HEAD(batch_list);
1122
1123 queue = verdict_instance_lookup(q, queue_num,
1124 NETLINK_CB(skb).portid);
1125 if (IS_ERR(queue))
1126 return PTR_ERR(queue);
1127
1128 vhdr = verdicthdr_get(nfqa);
1129 if (!vhdr)
1130 return -EINVAL;
1131
1132 verdict = ntohl(vhdr->verdict);
1133 maxid = ntohl(vhdr->id);
1134
1135 spin_lock_bh(&queue->lock);
1136
1137 list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
1138 if (nfq_id_after(entry->id, maxid))
1139 break;
1140 __dequeue_entry(queue, entry);
1141 list_add_tail(&entry->list, &batch_list);
1142 }
1143
1144 spin_unlock_bh(&queue->lock);
1145
1146 if (list_empty(&batch_list))
1147 return -ENOENT;
1148
1149 list_for_each_entry_safe(entry, tmp, &batch_list, list) {
1150 if (nfqa[NFQA_MARK])
1151 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1152
1153 if (nfqa[NFQA_PRIORITY])
1154 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1155
1156 nfqnl_reinject(entry, verdict);
1157 }
1158 return 0;
1159 }
1160
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)1161 static struct nf_conn *nfqnl_ct_parse(const struct nfnl_ct_hook *nfnl_ct,
1162 const struct nlmsghdr *nlh,
1163 const struct nlattr * const nfqa[],
1164 struct nf_queue_entry *entry,
1165 enum ip_conntrack_info *ctinfo)
1166 {
1167 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
1168 struct nf_conn *ct;
1169
1170 ct = nf_ct_get(entry->skb, ctinfo);
1171 if (ct == NULL)
1172 return NULL;
1173
1174 if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
1175 return NULL;
1176
1177 if (nfqa[NFQA_EXP])
1178 nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
1179 NETLINK_CB(entry->skb).portid,
1180 nlmsg_report(nlh));
1181 return ct;
1182 #else
1183 return NULL;
1184 #endif
1185 }
1186
nfqa_parse_bridge(struct nf_queue_entry * entry,const struct nlattr * const nfqa[])1187 static int nfqa_parse_bridge(struct nf_queue_entry *entry,
1188 const struct nlattr * const nfqa[])
1189 {
1190 if (nfqa[NFQA_VLAN]) {
1191 struct nlattr *tb[NFQA_VLAN_MAX + 1];
1192 int err;
1193
1194 err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX,
1195 nfqa[NFQA_VLAN],
1196 nfqa_vlan_policy, NULL);
1197 if (err < 0)
1198 return err;
1199
1200 if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
1201 return -EINVAL;
1202
1203 __vlan_hwaccel_put_tag(entry->skb,
1204 nla_get_be16(tb[NFQA_VLAN_PROTO]),
1205 ntohs(nla_get_be16(tb[NFQA_VLAN_TCI])));
1206 }
1207
1208 if (nfqa[NFQA_L2HDR]) {
1209 int mac_header_len = entry->skb->network_header -
1210 entry->skb->mac_header;
1211
1212 if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
1213 return -EINVAL;
1214 else if (mac_header_len > 0)
1215 memcpy(skb_mac_header(entry->skb),
1216 nla_data(nfqa[NFQA_L2HDR]),
1217 mac_header_len);
1218 }
1219
1220 return 0;
1221 }
1222
nfqnl_recv_verdict(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1223 static int nfqnl_recv_verdict(struct sk_buff *skb, const struct nfnl_info *info,
1224 const struct nlattr * const nfqa[])
1225 {
1226 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1227 u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1228 const struct nfnl_ct_hook *nfnl_ct;
1229 struct nfqnl_msg_verdict_hdr *vhdr;
1230 enum ip_conntrack_info ctinfo;
1231 struct nfqnl_instance *queue;
1232 struct nf_queue_entry *entry;
1233 struct nf_conn *ct = NULL;
1234 unsigned int verdict;
1235 int err;
1236
1237 queue = verdict_instance_lookup(q, queue_num,
1238 NETLINK_CB(skb).portid);
1239 if (IS_ERR(queue))
1240 return PTR_ERR(queue);
1241
1242 vhdr = verdicthdr_get(nfqa);
1243 if (!vhdr)
1244 return -EINVAL;
1245
1246 verdict = ntohl(vhdr->verdict);
1247
1248 entry = find_dequeue_entry(queue, ntohl(vhdr->id));
1249 if (entry == NULL)
1250 return -ENOENT;
1251
1252 /* rcu lock already held from nfnl->call_rcu. */
1253 nfnl_ct = rcu_dereference(nfnl_ct_hook);
1254
1255 if (nfqa[NFQA_CT]) {
1256 if (nfnl_ct != NULL)
1257 ct = nfqnl_ct_parse(nfnl_ct, info->nlh, nfqa, entry,
1258 &ctinfo);
1259 }
1260
1261 if (entry->state.pf == PF_BRIDGE) {
1262 err = nfqa_parse_bridge(entry, nfqa);
1263 if (err < 0)
1264 return err;
1265 }
1266
1267 if (nfqa[NFQA_PAYLOAD]) {
1268 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
1269 int diff = payload_len - entry->skb->len;
1270
1271 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
1272 payload_len, entry, diff) < 0)
1273 verdict = NF_DROP;
1274
1275 if (ct && diff)
1276 nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
1277 }
1278
1279 if (nfqa[NFQA_MARK])
1280 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1281
1282 if (nfqa[NFQA_PRIORITY])
1283 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1284
1285 nfqnl_reinject(entry, verdict);
1286 return 0;
1287 }
1288
nfqnl_recv_unsupp(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const cda[])1289 static int nfqnl_recv_unsupp(struct sk_buff *skb, const struct nfnl_info *info,
1290 const struct nlattr * const cda[])
1291 {
1292 return -ENOTSUPP;
1293 }
1294
1295 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
1296 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
1297 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
1298 [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 },
1299 [NFQA_CFG_MASK] = { .type = NLA_U32 },
1300 [NFQA_CFG_FLAGS] = { .type = NLA_U32 },
1301 };
1302
1303 static const struct nf_queue_handler nfqh = {
1304 .outfn = nfqnl_enqueue_packet,
1305 .nf_hook_drop = nfqnl_nf_hook_drop,
1306 };
1307
nfqnl_recv_config(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1308 static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info,
1309 const struct nlattr * const nfqa[])
1310 {
1311 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1312 u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1313 struct nfqnl_msg_config_cmd *cmd = NULL;
1314 struct nfqnl_instance *queue;
1315 __u32 flags = 0, mask = 0;
1316 int ret = 0;
1317
1318 if (nfqa[NFQA_CFG_CMD]) {
1319 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1320
1321 /* Obsolete commands without queue context */
1322 switch (cmd->command) {
1323 case NFQNL_CFG_CMD_PF_BIND: return 0;
1324 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1325 }
1326 }
1327
1328 /* Check if we support these flags in first place, dependencies should
1329 * be there too not to break atomicity.
1330 */
1331 if (nfqa[NFQA_CFG_FLAGS]) {
1332 if (!nfqa[NFQA_CFG_MASK]) {
1333 /* A mask is needed to specify which flags are being
1334 * changed.
1335 */
1336 return -EINVAL;
1337 }
1338
1339 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1340 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1341
1342 if (flags >= NFQA_CFG_F_MAX)
1343 return -EOPNOTSUPP;
1344
1345 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
1346 if (flags & mask & NFQA_CFG_F_SECCTX)
1347 return -EOPNOTSUPP;
1348 #endif
1349 if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
1350 !rcu_access_pointer(nfnl_ct_hook)) {
1351 #ifdef CONFIG_MODULES
1352 nfnl_unlock(NFNL_SUBSYS_QUEUE);
1353 request_module("ip_conntrack_netlink");
1354 nfnl_lock(NFNL_SUBSYS_QUEUE);
1355 if (rcu_access_pointer(nfnl_ct_hook))
1356 return -EAGAIN;
1357 #endif
1358 return -EOPNOTSUPP;
1359 }
1360 }
1361
1362 rcu_read_lock();
1363 queue = instance_lookup(q, queue_num);
1364 if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1365 ret = -EPERM;
1366 goto err_out_unlock;
1367 }
1368
1369 if (cmd != NULL) {
1370 switch (cmd->command) {
1371 case NFQNL_CFG_CMD_BIND:
1372 if (queue) {
1373 ret = -EBUSY;
1374 goto err_out_unlock;
1375 }
1376 queue = instance_create(q, queue_num,
1377 NETLINK_CB(skb).portid);
1378 if (IS_ERR(queue)) {
1379 ret = PTR_ERR(queue);
1380 goto err_out_unlock;
1381 }
1382 break;
1383 case NFQNL_CFG_CMD_UNBIND:
1384 if (!queue) {
1385 ret = -ENODEV;
1386 goto err_out_unlock;
1387 }
1388 instance_destroy(q, queue);
1389 goto err_out_unlock;
1390 case NFQNL_CFG_CMD_PF_BIND:
1391 case NFQNL_CFG_CMD_PF_UNBIND:
1392 break;
1393 default:
1394 ret = -ENOTSUPP;
1395 goto err_out_unlock;
1396 }
1397 }
1398
1399 if (!queue) {
1400 ret = -ENODEV;
1401 goto err_out_unlock;
1402 }
1403
1404 if (nfqa[NFQA_CFG_PARAMS]) {
1405 struct nfqnl_msg_config_params *params =
1406 nla_data(nfqa[NFQA_CFG_PARAMS]);
1407
1408 nfqnl_set_mode(queue, params->copy_mode,
1409 ntohl(params->copy_range));
1410 }
1411
1412 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1413 __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1414
1415 spin_lock_bh(&queue->lock);
1416 queue->queue_maxlen = ntohl(*queue_maxlen);
1417 spin_unlock_bh(&queue->lock);
1418 }
1419
1420 if (nfqa[NFQA_CFG_FLAGS]) {
1421 spin_lock_bh(&queue->lock);
1422 queue->flags &= ~mask;
1423 queue->flags |= flags & mask;
1424 spin_unlock_bh(&queue->lock);
1425 }
1426
1427 err_out_unlock:
1428 rcu_read_unlock();
1429 return ret;
1430 }
1431
1432 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1433 [NFQNL_MSG_PACKET] = {
1434 .call = nfqnl_recv_unsupp,
1435 .type = NFNL_CB_RCU,
1436 .attr_count = NFQA_MAX,
1437 },
1438 [NFQNL_MSG_VERDICT] = {
1439 .call = nfqnl_recv_verdict,
1440 .type = NFNL_CB_RCU,
1441 .attr_count = NFQA_MAX,
1442 .policy = nfqa_verdict_policy
1443 },
1444 [NFQNL_MSG_CONFIG] = {
1445 .call = nfqnl_recv_config,
1446 .type = NFNL_CB_MUTEX,
1447 .attr_count = NFQA_CFG_MAX,
1448 .policy = nfqa_cfg_policy
1449 },
1450 [NFQNL_MSG_VERDICT_BATCH] = {
1451 .call = nfqnl_recv_verdict_batch,
1452 .type = NFNL_CB_RCU,
1453 .attr_count = NFQA_MAX,
1454 .policy = nfqa_verdict_batch_policy
1455 },
1456 };
1457
1458 static const struct nfnetlink_subsystem nfqnl_subsys = {
1459 .name = "nf_queue",
1460 .subsys_id = NFNL_SUBSYS_QUEUE,
1461 .cb_count = NFQNL_MSG_MAX,
1462 .cb = nfqnl_cb,
1463 };
1464
1465 #ifdef CONFIG_PROC_FS
1466 struct iter_state {
1467 struct seq_net_private p;
1468 unsigned int bucket;
1469 };
1470
get_first(struct seq_file * seq)1471 static struct hlist_node *get_first(struct seq_file *seq)
1472 {
1473 struct iter_state *st = seq->private;
1474 struct net *net;
1475 struct nfnl_queue_net *q;
1476
1477 if (!st)
1478 return NULL;
1479
1480 net = seq_file_net(seq);
1481 q = nfnl_queue_pernet(net);
1482 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1483 if (!hlist_empty(&q->instance_table[st->bucket]))
1484 return q->instance_table[st->bucket].first;
1485 }
1486 return NULL;
1487 }
1488
get_next(struct seq_file * seq,struct hlist_node * h)1489 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1490 {
1491 struct iter_state *st = seq->private;
1492 struct net *net = seq_file_net(seq);
1493
1494 h = h->next;
1495 while (!h) {
1496 struct nfnl_queue_net *q;
1497
1498 if (++st->bucket >= INSTANCE_BUCKETS)
1499 return NULL;
1500
1501 q = nfnl_queue_pernet(net);
1502 h = q->instance_table[st->bucket].first;
1503 }
1504 return h;
1505 }
1506
get_idx(struct seq_file * seq,loff_t pos)1507 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1508 {
1509 struct hlist_node *head;
1510 head = get_first(seq);
1511
1512 if (head)
1513 while (pos && (head = get_next(seq, head)))
1514 pos--;
1515 return pos ? NULL : head;
1516 }
1517
seq_start(struct seq_file * s,loff_t * pos)1518 static void *seq_start(struct seq_file *s, loff_t *pos)
1519 __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1520 {
1521 spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1522 return get_idx(s, *pos);
1523 }
1524
seq_next(struct seq_file * s,void * v,loff_t * pos)1525 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1526 {
1527 (*pos)++;
1528 return get_next(s, v);
1529 }
1530
seq_stop(struct seq_file * s,void * v)1531 static void seq_stop(struct seq_file *s, void *v)
1532 __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1533 {
1534 spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1535 }
1536
seq_show(struct seq_file * s,void * v)1537 static int seq_show(struct seq_file *s, void *v)
1538 {
1539 const struct nfqnl_instance *inst = v;
1540
1541 seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
1542 inst->queue_num,
1543 inst->peer_portid, inst->queue_total,
1544 inst->copy_mode, inst->copy_range,
1545 inst->queue_dropped, inst->queue_user_dropped,
1546 inst->id_sequence, 1);
1547 return 0;
1548 }
1549
1550 static const struct seq_operations nfqnl_seq_ops = {
1551 .start = seq_start,
1552 .next = seq_next,
1553 .stop = seq_stop,
1554 .show = seq_show,
1555 };
1556 #endif /* PROC_FS */
1557
nfnl_queue_net_init(struct net * net)1558 static int __net_init nfnl_queue_net_init(struct net *net)
1559 {
1560 unsigned int i;
1561 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1562
1563 for (i = 0; i < INSTANCE_BUCKETS; i++)
1564 INIT_HLIST_HEAD(&q->instance_table[i]);
1565
1566 spin_lock_init(&q->instances_lock);
1567
1568 #ifdef CONFIG_PROC_FS
1569 if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter,
1570 &nfqnl_seq_ops, sizeof(struct iter_state)))
1571 return -ENOMEM;
1572 #endif
1573 return 0;
1574 }
1575
nfnl_queue_net_exit(struct net * net)1576 static void __net_exit nfnl_queue_net_exit(struct net *net)
1577 {
1578 struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1579 unsigned int i;
1580
1581 #ifdef CONFIG_PROC_FS
1582 remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1583 #endif
1584 for (i = 0; i < INSTANCE_BUCKETS; i++)
1585 WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
1586 }
1587
1588 static struct pernet_operations nfnl_queue_net_ops = {
1589 .init = nfnl_queue_net_init,
1590 .exit = nfnl_queue_net_exit,
1591 .id = &nfnl_queue_net_id,
1592 .size = sizeof(struct nfnl_queue_net),
1593 };
1594
nfnetlink_queue_init(void)1595 static int __init nfnetlink_queue_init(void)
1596 {
1597 int status;
1598
1599 status = register_pernet_subsys(&nfnl_queue_net_ops);
1600 if (status < 0) {
1601 pr_err("failed to register pernet ops\n");
1602 goto out;
1603 }
1604
1605 netlink_register_notifier(&nfqnl_rtnl_notifier);
1606 status = nfnetlink_subsys_register(&nfqnl_subsys);
1607 if (status < 0) {
1608 pr_err("failed to create netlink socket\n");
1609 goto cleanup_netlink_notifier;
1610 }
1611
1612 status = register_netdevice_notifier(&nfqnl_dev_notifier);
1613 if (status < 0) {
1614 pr_err("failed to register netdevice notifier\n");
1615 goto cleanup_netlink_subsys;
1616 }
1617
1618 nf_register_queue_handler(&nfqh);
1619
1620 return status;
1621
1622 cleanup_netlink_subsys:
1623 nfnetlink_subsys_unregister(&nfqnl_subsys);
1624 cleanup_netlink_notifier:
1625 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1626 unregister_pernet_subsys(&nfnl_queue_net_ops);
1627 out:
1628 return status;
1629 }
1630
nfnetlink_queue_fini(void)1631 static void __exit nfnetlink_queue_fini(void)
1632 {
1633 nf_unregister_queue_handler();
1634 unregister_netdevice_notifier(&nfqnl_dev_notifier);
1635 nfnetlink_subsys_unregister(&nfqnl_subsys);
1636 netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1637 unregister_pernet_subsys(&nfnl_queue_net_ops);
1638
1639 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1640 }
1641
1642 MODULE_DESCRIPTION("netfilter packet queue handler");
1643 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1644 MODULE_LICENSE("GPL");
1645 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1646
1647 module_init(nfnetlink_queue_init);
1648 module_exit(nfnetlink_queue_fini);
1649