xref: /linux/net/netfilter/nfnetlink_queue.c (revision dc1d9408c961c1c4d4b3b99a1d9390c17e13de71)
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 <linux/rhashtable.h>
34 #include <linux/jhash.h>
35 #include <net/gso.h>
36 #include <net/sock.h>
37 #include <net/tcp_states.h>
38 #include <net/netfilter/nf_queue.h>
39 #include <net/netns/generic.h>
40 
41 #include <linux/atomic.h>
42 
43 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
44 #include "../bridge/br_private.h"
45 #endif
46 
47 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
48 #include <net/netfilter/nf_conntrack.h>
49 #endif
50 
51 #define NFQNL_QMAX_DEFAULT 1024
52 #define NFQNL_HASH_MIN     8
53 #define NFQNL_HASH_MAX     32768
54 
55 /* We're using struct nlattr which has 16bit nla_len. Note that nla_len
56  * includes the header length. Thus, the maximum packet length that we
57  * support is 65531 bytes. We send truncated packets if the specified length
58  * is larger than that.  Userspace can check for presence of NFQA_CAP_LEN
59  * attribute to detect truncation.
60  */
61 #define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN)
62 
63 struct nfqnl_instance {
64 	struct hlist_node hlist;		/* global list of queues */
65 	struct rhashtable nfqnl_packet_map;
66 	struct rcu_work	rwork;
67 
68 	u32 peer_portid;
69 	unsigned int queue_maxlen;
70 	unsigned int copy_range;
71 	unsigned int queue_dropped;
72 	unsigned int queue_user_dropped;
73 
74 
75 	u_int16_t queue_num;			/* number of this queue */
76 	u_int8_t copy_mode;
77 	u_int32_t flags;			/* Set using NFQA_CFG_FLAGS */
78 /*
79  * Following fields are dirtied for each queued packet,
80  * keep them in same cache line if possible.
81  */
82 	spinlock_t	lock	____cacheline_aligned_in_smp;
83 	unsigned int	queue_total;
84 	unsigned int	id_sequence;		/* 'sequence' of pkt ids */
85 	struct list_head queue_list;		/* packets in queue */
86 };
87 
88 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
89 
90 static struct workqueue_struct *nfq_cleanup_wq __read_mostly;
91 static unsigned int nfnl_queue_net_id __read_mostly;
92 
93 #define INSTANCE_BUCKETS	16
94 struct nfnl_queue_net {
95 	spinlock_t instances_lock;
96 	struct hlist_head instance_table[INSTANCE_BUCKETS];
97 };
98 
nfnl_queue_pernet(struct net * net)99 static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net)
100 {
101 	return net_generic(net, nfnl_queue_net_id);
102 }
103 
instance_hashfn(u_int16_t queue_num)104 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
105 {
106 	return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS;
107 }
108 
109 static const struct rhashtable_params nfqnl_rhashtable_params = {
110 	.head_offset = offsetof(struct nf_queue_entry, hash_node),
111 	.key_offset = offsetof(struct nf_queue_entry, id),
112 	.key_len = sizeof(u32),
113 	.automatic_shrinking = true,
114 	.min_size = NFQNL_HASH_MIN,
115 	.max_size = NFQNL_HASH_MAX,
116 };
117 
118 static struct nfqnl_instance *
instance_lookup(struct nfnl_queue_net * q,u_int16_t queue_num)119 instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num)
120 {
121 	struct hlist_head *head;
122 	struct nfqnl_instance *inst;
123 
124 	head = &q->instance_table[instance_hashfn(queue_num)];
125 	hlist_for_each_entry_rcu(inst, head, hlist) {
126 		if (inst->queue_num == queue_num)
127 			return inst;
128 	}
129 	return NULL;
130 }
131 
132 static struct nfqnl_instance *
instance_create(struct nfnl_queue_net * q,u_int16_t queue_num,u32 portid)133 instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid)
134 {
135 	struct nfqnl_instance *inst;
136 	unsigned int h;
137 	int err;
138 
139 	inst = kzalloc_obj(*inst, GFP_KERNEL_ACCOUNT);
140 	if (!inst)
141 		return ERR_PTR(-ENOMEM);
142 
143 	inst->queue_num = queue_num;
144 	inst->peer_portid = portid;
145 	inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
146 	inst->copy_range = NFQNL_MAX_COPY_RANGE;
147 	inst->copy_mode = NFQNL_COPY_NONE;
148 	spin_lock_init(&inst->lock);
149 	INIT_LIST_HEAD(&inst->queue_list);
150 
151 	err = rhashtable_init(&inst->nfqnl_packet_map, &nfqnl_rhashtable_params);
152 	if (err < 0)
153 		goto out_free;
154 
155 	spin_lock(&q->instances_lock);
156 	if (instance_lookup(q, queue_num)) {
157 		err = -EEXIST;
158 		goto out_unlock;
159 	}
160 
161 	if (!try_module_get(THIS_MODULE)) {
162 		err = -EAGAIN;
163 		goto out_unlock;
164 	}
165 
166 	h = instance_hashfn(queue_num);
167 	hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]);
168 
169 	spin_unlock(&q->instances_lock);
170 
171 	return inst;
172 
173 out_unlock:
174 	spin_unlock(&q->instances_lock);
175 	rhashtable_destroy(&inst->nfqnl_packet_map);
176 out_free:
177 	kfree(inst);
178 	return ERR_PTR(err);
179 }
180 
181 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
182 			unsigned long data);
183 
instance_destroy_work(struct work_struct * work)184 static void instance_destroy_work(struct work_struct *work)
185 {
186 	struct nfqnl_instance *inst;
187 
188 	inst = container_of(to_rcu_work(work), struct nfqnl_instance,
189 			    rwork);
190 	rcu_read_lock();
191 	nfqnl_flush(inst, NULL, 0);
192 	rcu_read_unlock();
193 
194 	rhashtable_destroy(&inst->nfqnl_packet_map);
195 
196 	kfree(inst);
197 	module_put(THIS_MODULE);
198 }
199 
200 static void
__instance_destroy(struct nfqnl_instance * inst)201 __instance_destroy(struct nfqnl_instance *inst)
202 {
203 	hlist_del_rcu(&inst->hlist);
204 
205 	INIT_RCU_WORK(&inst->rwork, instance_destroy_work);
206 	queue_rcu_work(nfq_cleanup_wq, &inst->rwork);
207 }
208 
209 static void
instance_destroy(struct nfnl_queue_net * q,struct nfqnl_instance * inst)210 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
211 {
212 	spin_lock(&q->instances_lock);
213 	__instance_destroy(inst);
214 	spin_unlock(&q->instances_lock);
215 }
216 
217 static int
__enqueue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)218 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
219 {
220 	int err;
221 
222 	err = rhashtable_insert_fast(&queue->nfqnl_packet_map, &entry->hash_node,
223 				     nfqnl_rhashtable_params);
224 	if (unlikely(err))
225 		return err;
226 
227 	list_add_tail(&entry->list, &queue->queue_list);
228 	queue->queue_total++;
229 
230 	return 0;
231 }
232 
233 static void
__dequeue_entry(struct nfqnl_instance * queue,struct nf_queue_entry * entry)234 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
235 {
236 	rhashtable_remove_fast(&queue->nfqnl_packet_map, &entry->hash_node,
237 			       nfqnl_rhashtable_params);
238 	list_del(&entry->list);
239 	queue->queue_total--;
240 }
241 
242 static struct nf_queue_entry *
find_dequeue_entry(struct nfqnl_instance * queue,unsigned int id)243 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
244 {
245 	struct nf_queue_entry *entry;
246 
247 	spin_lock_bh(&queue->lock);
248 	entry = rhashtable_lookup_fast(&queue->nfqnl_packet_map, &id,
249 				       nfqnl_rhashtable_params);
250 
251 	if (entry)
252 		__dequeue_entry(queue, entry);
253 
254 	spin_unlock_bh(&queue->lock);
255 
256 	return entry;
257 }
258 
nf_iterate(struct sk_buff * skb,struct nf_hook_state * state,const struct nf_hook_entries * hooks,unsigned int * index)259 static unsigned int nf_iterate(struct sk_buff *skb,
260 			       struct nf_hook_state *state,
261 			       const struct nf_hook_entries *hooks,
262 			       unsigned int *index)
263 {
264 	const struct nf_hook_entry *hook;
265 	unsigned int verdict, i = *index;
266 
267 	while (i < hooks->num_hook_entries) {
268 		hook = &hooks->hooks[i];
269 repeat:
270 		verdict = nf_hook_entry_hookfn(hook, skb, state);
271 		if (verdict != NF_ACCEPT) {
272 			*index = i;
273 			if (verdict != NF_REPEAT)
274 				return verdict;
275 			goto repeat;
276 		}
277 		i++;
278 	}
279 
280 	*index = i;
281 	return NF_ACCEPT;
282 }
283 
nf_hook_entries_head(const struct net * net,u8 pf,u8 hooknum)284 static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum)
285 {
286 	switch (pf) {
287 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
288 	case NFPROTO_BRIDGE:
289 		return rcu_dereference(net->nf.hooks_bridge[hooknum]);
290 #endif
291 	case NFPROTO_IPV4:
292 		return rcu_dereference(net->nf.hooks_ipv4[hooknum]);
293 	case NFPROTO_IPV6:
294 		return rcu_dereference(net->nf.hooks_ipv6[hooknum]);
295 	default:
296 		WARN_ON_ONCE(1);
297 		return NULL;
298 	}
299 
300 	return NULL;
301 }
302 
nf_ip_reroute(struct sk_buff * skb,const struct nf_queue_entry * entry)303 static int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry)
304 {
305 #ifdef CONFIG_INET
306 	const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
307 
308 	if (entry->state.hook == NF_INET_LOCAL_OUT) {
309 		const struct iphdr *iph = ip_hdr(skb);
310 
311 		if (!(iph->tos == rt_info->tos &&
312 		      skb->mark == rt_info->mark &&
313 		      iph->daddr == rt_info->daddr &&
314 		      iph->saddr == rt_info->saddr))
315 			return ip_route_me_harder(entry->state.net, entry->state.sk,
316 						  skb, RTN_UNSPEC);
317 	}
318 #endif
319 	return 0;
320 }
321 
nf_ip6_reroute(struct sk_buff * skb,const struct nf_queue_entry * entry)322 static int nf_ip6_reroute(struct sk_buff *skb,
323 			  const struct nf_queue_entry *entry)
324 {
325 	struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
326 
327 	if (entry->state.hook == NF_INET_LOCAL_OUT) {
328 		const struct ipv6hdr *iph = ipv6_hdr(skb);
329 
330 		if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
331 		    !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
332 		    skb->mark != rt_info->mark)
333 			return nf_ip6_route_me_harder(entry->state.net,
334 						      entry->state.sk, skb);
335 	}
336 	return 0;
337 }
338 
nf_reroute(struct sk_buff * skb,struct nf_queue_entry * entry)339 static int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
340 {
341 	int ret = 0;
342 
343 	switch (entry->state.pf) {
344 	case AF_INET:
345 		ret = nf_ip_reroute(skb, entry);
346 		break;
347 	case AF_INET6:
348 		ret = nf_ip6_reroute(skb, entry);
349 		break;
350 	}
351 	return ret;
352 }
353 
354 /* caller must hold rcu read-side lock */
nf_reinject(struct nf_queue_entry * entry,unsigned int verdict)355 static void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
356 {
357 	const struct nf_hook_entry *hook_entry;
358 	const struct nf_hook_entries *hooks;
359 	struct sk_buff *skb = entry->skb;
360 	const struct net *net;
361 	unsigned int i;
362 	int err;
363 	u8 pf;
364 
365 	net = entry->state.net;
366 	pf = entry->state.pf;
367 
368 	hooks = nf_hook_entries_head(net, pf, entry->state.hook);
369 
370 	i = entry->hook_index;
371 	if (!hooks || i >= hooks->num_hook_entries) {
372 		kfree_skb_reason(skb, SKB_DROP_REASON_NETFILTER_DROP);
373 		nf_queue_entry_free(entry);
374 		return;
375 	}
376 
377 	hook_entry = &hooks->hooks[i];
378 
379 	/* Continue traversal iff userspace said ok... */
380 	if (verdict == NF_REPEAT)
381 		verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state);
382 
383 	if (verdict == NF_ACCEPT) {
384 		if (nf_reroute(skb, entry) < 0)
385 			verdict = NF_DROP;
386 	}
387 
388 	if (verdict == NF_ACCEPT) {
389 next_hook:
390 		++i;
391 		verdict = nf_iterate(skb, &entry->state, hooks, &i);
392 	}
393 
394 	switch (verdict & NF_VERDICT_MASK) {
395 	case NF_ACCEPT:
396 	case NF_STOP:
397 		local_bh_disable();
398 		entry->state.okfn(entry->state.net, entry->state.sk, skb);
399 		local_bh_enable();
400 		break;
401 	case NF_QUEUE:
402 		err = nf_queue(skb, &entry->state, i, verdict);
403 		if (err == 1)
404 			goto next_hook;
405 		break;
406 	case NF_STOLEN:
407 		break;
408 	default:
409 		kfree_skb(skb);
410 	}
411 
412 	nf_queue_entry_free(entry);
413 }
414 
415 /* return true if the entry has an unconfirmed conntrack attached that isn't owned by us
416  * exclusively.
417  */
nf_ct_drop_unconfirmed(const struct nf_queue_entry * entry,bool * is_unconfirmed)418 static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry, bool *is_unconfirmed)
419 {
420 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
421 	struct nf_conn *ct = (void *)skb_nfct(entry->skb);
422 
423 	if (!ct || nf_ct_is_confirmed(ct))
424 		return false;
425 
426 	if (is_unconfirmed)
427 		*is_unconfirmed = true;
428 
429 	/* in some cases skb_clone() can occur after initial conntrack
430 	 * pickup, but conntrack assumes exclusive skb->_nfct ownership for
431 	 * unconfirmed entries.
432 	 *
433 	 * This happens for br_netfilter and with ip multicast routing.
434 	 * This can't be solved with serialization here because one clone
435 	 * could have been queued for local delivery or could be transmitted
436 	 * in parallel on another CPU.
437 	 */
438 	return refcount_read(&ct->ct_general.use) > 1;
439 #endif
440 	return false;
441 }
442 
nfqnl_reinject(struct nf_queue_entry * entry,unsigned int verdict)443 static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict)
444 {
445 	const struct nf_ct_hook *ct_hook;
446 
447 	if (verdict == NF_ACCEPT ||
448 	    verdict == NF_REPEAT ||
449 	    verdict == NF_STOP) {
450 		unsigned int ct_verdict = verdict;
451 
452 		rcu_read_lock();
453 		ct_hook = rcu_dereference(nf_ct_hook);
454 		if (ct_hook)
455 			ct_verdict = ct_hook->update(entry->state.net, entry->skb);
456 		rcu_read_unlock();
457 
458 		switch (ct_verdict & NF_VERDICT_MASK) {
459 		case NF_ACCEPT:
460 			/* follow userspace verdict, could be REPEAT */
461 			break;
462 		case NF_STOLEN:
463 			nf_queue_entry_free(entry);
464 			return;
465 		default:
466 			verdict = ct_verdict & NF_VERDICT_MASK;
467 			break;
468 		}
469 	}
470 
471 	if (verdict != NF_DROP && entry->nf_ct_is_unconfirmed) {
472 		/* If first queued segment was already reinjected then
473 		 * there is a good chance the ct entry is now confirmed.
474 		 *
475 		 * Handle the rare cases:
476 		 *  - out-of-order verdict
477 		 *  - threaded userspace reinjecting in parallel
478 		 *  - first segment was dropped
479 		 *
480 		 * In all of those cases we can't handle this packet
481 		 * because we can't be sure that another CPU won't modify
482 		 * nf_conn->ext in parallel which isn't allowed.
483 		 */
484 		if (nf_ct_drop_unconfirmed(entry, NULL))
485 			verdict = NF_DROP;
486 	}
487 
488 	nf_reinject(entry, verdict);
489 }
490 
491 static void
nfqnl_flush(struct nfqnl_instance * queue,nfqnl_cmpfn cmpfn,unsigned long data)492 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
493 {
494 	struct nf_queue_entry *entry, *next;
495 
496 	spin_lock_bh(&queue->lock);
497 	list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
498 		if (!cmpfn || cmpfn(entry, data)) {
499 			__dequeue_entry(queue, entry);
500 			nfqnl_reinject(entry, NF_DROP);
501 		}
502 	}
503 	spin_unlock_bh(&queue->lock);
504 }
505 
506 static int
nfqnl_put_packet_info(struct sk_buff * nlskb,struct sk_buff * packet,bool csum_verify)507 nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet,
508 		      bool csum_verify)
509 {
510 	__u32 flags = 0;
511 
512 	if (packet->ip_summed == CHECKSUM_PARTIAL)
513 		flags = NFQA_SKB_CSUMNOTREADY;
514 	else if (csum_verify)
515 		flags = NFQA_SKB_CSUM_NOTVERIFIED;
516 
517 	if (skb_is_gso(packet))
518 		flags |= NFQA_SKB_GSO;
519 
520 	return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0;
521 }
522 
nfqnl_put_sk_uidgid(struct sk_buff * skb,struct sock * sk)523 static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
524 {
525 	const struct socket *sock;
526 	const struct file *file;
527 	const struct cred *cred;
528 
529 	if (!sk_fullsock(sk))
530 		return 0;
531 
532 	/* The sk pointer remains valid as long as the skb is.
533 	 * The sk_socket and file pointer may become NULL
534 	 * if the socket is closed.
535 	 * Both structures (including file->cred) are RCU freed
536 	 * which means they can be accessed within a RCU read section.
537 	 */
538 	sock = READ_ONCE(sk->sk_socket);
539 	file = sock ? READ_ONCE(sock->file) : NULL;
540 	if (file) {
541 		cred = file->f_cred;
542 		if (nla_put_be32(skb, NFQA_UID,
543 		    htonl(from_kuid_munged(&init_user_ns, cred->fsuid))))
544 			goto nla_put_failure;
545 		if (nla_put_be32(skb, NFQA_GID,
546 		    htonl(from_kgid_munged(&init_user_ns, cred->fsgid))))
547 			goto nla_put_failure;
548 	}
549 	return 0;
550 
551 nla_put_failure:
552 	return -1;
553 }
554 
nfqnl_put_sk_classid(struct sk_buff * skb,struct sock * sk)555 static int nfqnl_put_sk_classid(struct sk_buff *skb, struct sock *sk)
556 {
557 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
558 	if (sk && sk_fullsock(sk)) {
559 		u32 classid = sock_cgroup_classid(&sk->sk_cgrp_data);
560 
561 		if (classid && nla_put_be32(skb, NFQA_CGROUP_CLASSID, htonl(classid)))
562 			return -1;
563 	}
564 #endif
565 	return 0;
566 }
567 
nfqnl_get_sk_secctx(struct sk_buff * skb,struct lsm_context * ctx)568 static int nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsm_context *ctx)
569 {
570 	int seclen = 0;
571 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
572 	if (skb->secmark)
573 		seclen = security_secid_to_secctx(skb->secmark, ctx);
574 #endif
575 	return seclen;
576 }
577 
nfqnl_get_bridge_size(struct nf_queue_entry * entry)578 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
579 {
580 	struct sk_buff *entskb = entry->skb;
581 	u32 nlalen = 0;
582 	u32 mac_len;
583 
584 	if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
585 		return 0;
586 
587 	if (skb_vlan_tag_present(entskb))
588 		nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
589 					 nla_total_size(sizeof(__be16)));
590 
591 	mac_len = skb_mac_header_len(entskb);
592 	if (mac_len > 0)
593 		nlalen += nla_total_size(mac_len);
594 
595 	return nlalen;
596 }
597 
nfqnl_put_bridge(struct nf_queue_entry * entry,struct sk_buff * skb)598 static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
599 {
600 	struct sk_buff *entskb = entry->skb;
601 	u32 mac_len;
602 
603 	if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
604 		return 0;
605 
606 	if (skb_vlan_tag_present(entskb)) {
607 		struct nlattr *nest;
608 
609 		nest = nla_nest_start(skb, NFQA_VLAN);
610 		if (!nest)
611 			goto nla_put_failure;
612 
613 		if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
614 		    nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
615 			goto nla_put_failure;
616 
617 		nla_nest_end(skb, nest);
618 	}
619 
620 	mac_len = skb_mac_header_len(entskb);
621 	if (mac_len > 0 &&
622 	    nla_put(skb, NFQA_L2HDR, mac_len, skb_mac_header(entskb)))
623 		goto nla_put_failure;
624 
625 	return 0;
626 
627 nla_put_failure:
628 	return -1;
629 }
630 
nf_queue_checksum_help(struct sk_buff * entskb)631 static int nf_queue_checksum_help(struct sk_buff *entskb)
632 {
633 	if (skb_csum_is_sctp(entskb))
634 		return skb_crc32c_csum_help(entskb);
635 
636 	return skb_checksum_help(entskb);
637 }
638 
639 static struct sk_buff *
nfqnl_build_packet_message(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry,__be32 ** packet_id_ptr)640 nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
641 			   struct nf_queue_entry *entry,
642 			   __be32 **packet_id_ptr)
643 {
644 	size_t size;
645 	size_t data_len = 0, cap_len = 0;
646 	unsigned int hlen = 0;
647 	struct sk_buff *skb;
648 	struct nlattr *nla;
649 	struct nfqnl_msg_packet_hdr *pmsg;
650 	struct nlmsghdr *nlh;
651 	struct sk_buff *entskb = entry->skb;
652 	struct net_device *indev;
653 	struct net_device *outdev;
654 	struct nf_conn *ct = NULL;
655 	enum ip_conntrack_info ctinfo = 0;
656 	const struct nfnl_ct_hook *nfnl_ct;
657 	bool csum_verify;
658 	struct lsm_context ctx = { NULL, 0, 0 };
659 	int seclen = 0;
660 	ktime_t tstamp;
661 
662 	size = nlmsg_total_size(sizeof(struct nfgenmsg))
663 		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
664 		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
665 		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
666 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
667 		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
668 		+ nla_total_size(sizeof(u_int32_t))	/* ifindex */
669 #endif
670 		+ nla_total_size(sizeof(u_int32_t))	/* mark */
671 		+ nla_total_size(sizeof(u_int32_t))	/* priority */
672 		+ nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
673 		+ nla_total_size(sizeof(u_int32_t))	/* skbinfo */
674 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
675 		+ nla_total_size(sizeof(u_int32_t))	/* classid */
676 #endif
677 		+ nla_total_size(sizeof(u_int32_t));	/* cap_len */
678 
679 	tstamp = skb_tstamp_cond(entskb, false);
680 	if (tstamp)
681 		size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
682 
683 	size += nfqnl_get_bridge_size(entry);
684 
685 	if (entry->state.hook <= NF_INET_FORWARD ||
686 	   (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
687 		csum_verify = !skb_csum_unnecessary(entskb);
688 	else
689 		csum_verify = false;
690 
691 	outdev = entry->state.out;
692 
693 	switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) {
694 	case NFQNL_COPY_META:
695 	case NFQNL_COPY_NONE:
696 		break;
697 
698 	case NFQNL_COPY_PACKET:
699 		if (!(queue->flags & NFQA_CFG_F_GSO) &&
700 		    entskb->ip_summed == CHECKSUM_PARTIAL &&
701 		    nf_queue_checksum_help(entskb))
702 			return NULL;
703 
704 		data_len = READ_ONCE(queue->copy_range);
705 		if (data_len > entskb->len)
706 			data_len = entskb->len;
707 
708 		hlen = skb_zerocopy_headlen(entskb);
709 		hlen = min_t(unsigned int, hlen, data_len);
710 		size += sizeof(struct nlattr) + hlen;
711 		cap_len = entskb->len;
712 		break;
713 	}
714 
715 	nfnl_ct = rcu_dereference(nfnl_ct_hook);
716 
717 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
718 	if (queue->flags & NFQA_CFG_F_CONNTRACK) {
719 		if (nfnl_ct != NULL) {
720 			ct = nf_ct_get(entskb, &ctinfo);
721 			if (ct != NULL)
722 				size += nfnl_ct->build_size(ct);
723 		}
724 	}
725 #endif
726 
727 	if (queue->flags & NFQA_CFG_F_UID_GID) {
728 		size += (nla_total_size(sizeof(u_int32_t))	/* uid */
729 			+ nla_total_size(sizeof(u_int32_t)));	/* gid */
730 	}
731 
732 	if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
733 		seclen = nfqnl_get_sk_secctx(entskb, &ctx);
734 		if (seclen < 0)
735 			return NULL;
736 		if (seclen)
737 			size += nla_total_size(seclen);
738 	}
739 
740 	skb = alloc_skb(size, GFP_ATOMIC);
741 	if (!skb) {
742 		skb_tx_error(entskb);
743 		goto nlmsg_failure;
744 	}
745 
746 	nlh = nfnl_msg_put(skb, 0, 0,
747 			   nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET),
748 			   0, entry->state.pf, NFNETLINK_V0,
749 			   htons(queue->queue_num));
750 	if (!nlh) {
751 		skb_tx_error(entskb);
752 		kfree_skb(skb);
753 		goto nlmsg_failure;
754 	}
755 
756 	nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
757 	pmsg = nla_data(nla);
758 	pmsg->hw_protocol	= entskb->protocol;
759 	pmsg->hook		= entry->state.hook;
760 	*packet_id_ptr		= &pmsg->packet_id;
761 
762 	indev = entry->state.in;
763 	if (indev) {
764 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
765 		if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
766 			goto nla_put_failure;
767 #else
768 		if (entry->state.pf == PF_BRIDGE) {
769 			/* Case 1: indev is physical input device, we need to
770 			 * look for bridge group (when called from
771 			 * netfilter_bridge) */
772 			if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
773 					 htonl(indev->ifindex)) ||
774 			/* this is the bridge group "brX" */
775 			/* rcu_read_lock()ed by __nf_queue */
776 			    nla_put_be32(skb, NFQA_IFINDEX_INDEV,
777 					 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
778 				goto nla_put_failure;
779 		} else {
780 			int physinif;
781 
782 			/* Case 2: indev is bridge group, we need to look for
783 			 * physical device (when called from ipv4) */
784 			if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
785 					 htonl(indev->ifindex)))
786 				goto nla_put_failure;
787 
788 			physinif = nf_bridge_get_physinif(entskb);
789 			if (physinif &&
790 			    nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
791 					 htonl(physinif)))
792 				goto nla_put_failure;
793 		}
794 #endif
795 	}
796 
797 	if (outdev) {
798 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
799 		if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
800 			goto nla_put_failure;
801 #else
802 		if (entry->state.pf == PF_BRIDGE) {
803 			/* Case 1: outdev is physical output device, we need to
804 			 * look for bridge group (when called from
805 			 * netfilter_bridge) */
806 			if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
807 					 htonl(outdev->ifindex)) ||
808 			/* this is the bridge group "brX" */
809 			/* rcu_read_lock()ed by __nf_queue */
810 			    nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
811 					 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
812 				goto nla_put_failure;
813 		} else {
814 			int physoutif;
815 
816 			/* Case 2: outdev is bridge group, we need to look for
817 			 * physical output device (when called from ipv4) */
818 			if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
819 					 htonl(outdev->ifindex)))
820 				goto nla_put_failure;
821 
822 			physoutif = nf_bridge_get_physoutif(entskb);
823 			if (physoutif &&
824 			    nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
825 					 htonl(physoutif)))
826 				goto nla_put_failure;
827 		}
828 #endif
829 	}
830 
831 	if (entskb->mark &&
832 	    nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
833 		goto nla_put_failure;
834 
835 	if (entskb->priority &&
836 	    nla_put_be32(skb, NFQA_PRIORITY, htonl(entskb->priority)))
837 		goto nla_put_failure;
838 
839 	if (indev && entskb->dev &&
840 	    skb_mac_header_was_set(entskb) &&
841 	    skb_mac_header_len(entskb) != 0) {
842 		struct nfqnl_msg_packet_hw phw;
843 		int len;
844 
845 		memset(&phw, 0, sizeof(phw));
846 		len = dev_parse_header(entskb, phw.hw_addr);
847 		if (len) {
848 			phw.hw_addrlen = htons(len);
849 			if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
850 				goto nla_put_failure;
851 		}
852 	}
853 
854 	if (nfqnl_put_bridge(entry, skb) < 0)
855 		goto nla_put_failure;
856 
857 	if (entry->state.hook <= NF_INET_FORWARD && tstamp) {
858 		struct nfqnl_msg_packet_timestamp ts;
859 		struct timespec64 kts = ktime_to_timespec64(tstamp);
860 
861 		ts.sec = cpu_to_be64(kts.tv_sec);
862 		ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
863 
864 		if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
865 			goto nla_put_failure;
866 	}
867 
868 	if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
869 	    nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
870 		goto nla_put_failure;
871 
872 	if (nfqnl_put_sk_classid(skb, entskb->sk) < 0)
873 		goto nla_put_failure;
874 
875 	if (seclen > 0 && nla_put(skb, NFQA_SECCTX, ctx.len, ctx.context))
876 		goto nla_put_failure;
877 
878 	if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
879 		goto nla_put_failure;
880 
881 	if (cap_len > data_len &&
882 	    nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
883 		goto nla_put_failure;
884 
885 	if (nfqnl_put_packet_info(skb, entskb, csum_verify))
886 		goto nla_put_failure;
887 
888 	if (data_len) {
889 		struct nlattr *nla;
890 
891 		if (skb_tailroom(skb) < sizeof(*nla) + hlen)
892 			goto nla_put_failure;
893 
894 		nla = skb_put(skb, sizeof(*nla));
895 		nla->nla_type = NFQA_PAYLOAD;
896 		nla->nla_len = nla_attr_size(data_len);
897 
898 		if (skb_zerocopy(skb, entskb, data_len, hlen))
899 			goto nla_put_failure;
900 	}
901 
902 	nlh->nlmsg_len = skb->len;
903 	if (seclen >= 0)
904 		security_release_secctx(&ctx);
905 	return skb;
906 
907 nla_put_failure:
908 	skb_tx_error(entskb);
909 	kfree_skb(skb);
910 	net_err_ratelimited("nf_queue: error creating packet message\n");
911 nlmsg_failure:
912 	if (seclen >= 0)
913 		security_release_secctx(&ctx);
914 	return NULL;
915 }
916 
917 static int
__nfqnl_enqueue_packet(struct net * net,struct nfqnl_instance * queue,struct nf_queue_entry * entry)918 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
919 			struct nf_queue_entry *entry)
920 {
921 	struct sk_buff *nskb;
922 	int err = -ENOBUFS;
923 	__be32 *packet_id_ptr;
924 	int failopen = 0;
925 
926 	nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
927 	if (nskb == NULL) {
928 		err = -ENOMEM;
929 		goto err_out;
930 	}
931 	spin_lock_bh(&queue->lock);
932 
933 	if (queue->queue_total >= queue->queue_maxlen)
934 		goto err_out_queue_drop;
935 
936 	entry->id = ++queue->id_sequence;
937 	*packet_id_ptr = htonl(entry->id);
938 
939 	/* Insert into hash BEFORE unicast. If failure don't send to userspace. */
940 	err = __enqueue_entry(queue, entry);
941 	if (unlikely(err))
942 		goto err_out_queue_drop;
943 
944 	/* nfnetlink_unicast will either free the nskb or add it to a socket */
945 	err = nfnetlink_unicast(nskb, net, queue->peer_portid);
946 	if (err < 0) {
947 		/* Unicast failed - remove entry we just inserted */
948 		__dequeue_entry(queue, entry);
949 
950 		if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
951 			failopen = 1;
952 			err = 0;
953 		} else {
954 			queue->queue_user_dropped++;
955 		}
956 		goto err_out_unlock;
957 	}
958 
959 	spin_unlock_bh(&queue->lock);
960 	return 0;
961 
962 err_out_queue_drop:
963 	if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
964 		failopen = 1;
965 		err = 0;
966 	} else {
967 		queue->queue_dropped++;
968 
969 		if (queue->queue_total >= queue->queue_maxlen)
970 			net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
971 					     queue->queue_total);
972 		else
973 			net_warn_ratelimited("nf_queue: hash insert failed: %d\n", err);
974 	}
975 	kfree_skb(nskb);
976 err_out_unlock:
977 	spin_unlock_bh(&queue->lock);
978 	if (failopen)
979 		nfqnl_reinject(entry, NF_ACCEPT);
980 err_out:
981 	return err;
982 }
983 
984 static struct nf_queue_entry *
nf_queue_entry_dup(struct nf_queue_entry * e)985 nf_queue_entry_dup(struct nf_queue_entry *e)
986 {
987 	struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
988 
989 	if (!entry)
990 		return NULL;
991 
992 	if (nf_queue_entry_get_refs(entry))
993 		return entry;
994 
995 	kfree(entry);
996 	return NULL;
997 }
998 
999 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
1000 /* When called from bridge netfilter, skb->data must point to MAC header
1001  * before calling skb_gso_segment(). Else, original MAC header is lost
1002  * and segmented skbs will be sent to wrong destination.
1003  */
nf_bridge_adjust_skb_data(struct sk_buff * skb)1004 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
1005 {
1006 	if (nf_bridge_info_get(skb))
1007 		__skb_push(skb, skb_mac_header_len(skb));
1008 }
1009 
nf_bridge_adjust_segmented_data(struct sk_buff * skb)1010 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
1011 {
1012 	if (nf_bridge_info_get(skb))
1013 		__skb_pull(skb, skb_mac_header_len(skb));
1014 }
1015 #else
1016 #define nf_bridge_adjust_skb_data(s) do {} while (0)
1017 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
1018 #endif
1019 
1020 static int
__nfqnl_enqueue_packet_gso(struct net * net,struct nfqnl_instance * queue,struct sk_buff * skb,struct nf_queue_entry * entry)1021 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
1022 			   struct sk_buff *skb, struct nf_queue_entry *entry)
1023 {
1024 	int ret = -ENOMEM;
1025 	struct nf_queue_entry *entry_seg;
1026 
1027 	nf_bridge_adjust_segmented_data(skb);
1028 
1029 	if (skb->next == NULL) { /* last packet, no need to copy entry */
1030 		struct sk_buff *gso_skb = entry->skb;
1031 		entry->skb = skb;
1032 		ret = __nfqnl_enqueue_packet(net, queue, entry);
1033 		if (ret)
1034 			entry->skb = gso_skb;
1035 		return ret;
1036 	}
1037 
1038 	skb_mark_not_on_list(skb);
1039 
1040 	entry_seg = nf_queue_entry_dup(entry);
1041 	if (entry_seg) {
1042 		entry_seg->skb = skb;
1043 		ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
1044 		if (ret)
1045 			nf_queue_entry_free(entry_seg);
1046 	}
1047 	return ret;
1048 }
1049 
1050 static int
nfqnl_enqueue_packet(struct nf_queue_entry * entry,unsigned int queuenum)1051 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
1052 {
1053 	struct sk_buff *skb, *segs, *nskb;
1054 	bool ct_is_unconfirmed = false;
1055 	struct nfqnl_instance *queue;
1056 	unsigned int queued;
1057 	int err = -ENOBUFS;
1058 	struct net *net = entry->state.net;
1059 	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1060 
1061 	/* rcu_read_lock()ed by nf_hook_thresh */
1062 	queue = instance_lookup(q, queuenum);
1063 	if (!queue)
1064 		return -ESRCH;
1065 
1066 	if (queue->copy_mode == NFQNL_COPY_NONE)
1067 		return -EINVAL;
1068 
1069 	skb = entry->skb;
1070 
1071 	switch (entry->state.pf) {
1072 	case NFPROTO_IPV4:
1073 		skb->protocol = htons(ETH_P_IP);
1074 		break;
1075 	case NFPROTO_IPV6:
1076 		skb->protocol = htons(ETH_P_IPV6);
1077 		break;
1078 	}
1079 
1080 	/* Check if someone already holds another reference to
1081 	 * unconfirmed ct.  If so, we cannot queue the skb:
1082 	 * concurrent modifications of nf_conn->ext are not
1083 	 * allowed and we can't know if another CPU isn't
1084 	 * processing the same nf_conn entry in parallel.
1085 	 */
1086 	if (nf_ct_drop_unconfirmed(entry, &ct_is_unconfirmed))
1087 		return -EINVAL;
1088 
1089 	if (!skb_is_gso(skb) || ((queue->flags & NFQA_CFG_F_GSO) && !skb_is_gso_sctp(skb)))
1090 		return __nfqnl_enqueue_packet(net, queue, entry);
1091 
1092 	nf_bridge_adjust_skb_data(skb);
1093 	segs = skb_gso_segment(skb, 0);
1094 	/* Does not use PTR_ERR to limit the number of error codes that can be
1095 	 * returned by nf_queue.  For instance, callers rely on -ESRCH to
1096 	 * mean 'ignore this hook'.
1097 	 */
1098 	if (IS_ERR_OR_NULL(segs))
1099 		goto out_err;
1100 	queued = 0;
1101 	err = 0;
1102 
1103 	skb_list_walk_safe(segs, segs, nskb) {
1104 		if (ct_is_unconfirmed && queued > 0) {
1105 			/* skb_gso_segment() increments the ct refcount.
1106 			 * This is a problem for unconfirmed (not in hash)
1107 			 * entries, those can race when reinjections happen
1108 			 * in parallel.
1109 			 *
1110 			 * Annotate this for all queued entries except the
1111 			 * first one.
1112 			 *
1113 			 * As long as the first one is reinjected first it
1114 			 * will do the confirmation for us.
1115 			 */
1116 			entry->nf_ct_is_unconfirmed = ct_is_unconfirmed;
1117 		}
1118 
1119 		if (err == 0)
1120 			err = __nfqnl_enqueue_packet_gso(net, queue,
1121 							segs, entry);
1122 		if (err == 0)
1123 			queued++;
1124 		else
1125 			kfree_skb(segs);
1126 	}
1127 
1128 	if (queued) {
1129 		if (err) /* some segments are already queued */
1130 			nf_queue_entry_free(entry);
1131 		kfree_skb(skb);
1132 		return 0;
1133 	}
1134  out_err:
1135 	nf_bridge_adjust_segmented_data(skb);
1136 	return err;
1137 }
1138 
1139 static int
nfqnl_mangle(void * data,unsigned int data_len,struct nf_queue_entry * e,int diff)1140 nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff)
1141 {
1142 	struct sk_buff *nskb;
1143 
1144 	if (diff < 0) {
1145 		unsigned int min_len = skb_transport_offset(e->skb);
1146 
1147 		if (data_len < min_len)
1148 			return -EINVAL;
1149 
1150 		if (pskb_trim(e->skb, data_len))
1151 			return -ENOMEM;
1152 	} else if (diff > 0) {
1153 		if (data_len > 0xFFFF)
1154 			return -EINVAL;
1155 		if (diff > skb_tailroom(e->skb)) {
1156 			nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
1157 					       diff, GFP_ATOMIC);
1158 			if (!nskb)
1159 				return -ENOMEM;
1160 			kfree_skb(e->skb);
1161 			e->skb = nskb;
1162 		}
1163 		skb_put(e->skb, diff);
1164 	}
1165 	if (skb_ensure_writable(e->skb, data_len))
1166 		return -ENOMEM;
1167 	skb_copy_to_linear_data(e->skb, data, data_len);
1168 	e->skb->ip_summed = CHECKSUM_NONE;
1169 	return 0;
1170 }
1171 
1172 static int
nfqnl_set_mode(struct nfqnl_instance * queue,unsigned char mode,unsigned int range)1173 nfqnl_set_mode(struct nfqnl_instance *queue,
1174 	       unsigned char mode, unsigned int range)
1175 {
1176 	int status = 0;
1177 
1178 	spin_lock_bh(&queue->lock);
1179 	switch (mode) {
1180 	case NFQNL_COPY_NONE:
1181 	case NFQNL_COPY_META:
1182 		queue->copy_mode = mode;
1183 		queue->copy_range = 0;
1184 		break;
1185 
1186 	case NFQNL_COPY_PACKET:
1187 		queue->copy_mode = mode;
1188 		if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
1189 			queue->copy_range = NFQNL_MAX_COPY_RANGE;
1190 		else
1191 			queue->copy_range = range;
1192 		break;
1193 
1194 	default:
1195 		status = -EINVAL;
1196 
1197 	}
1198 	spin_unlock_bh(&queue->lock);
1199 
1200 	return status;
1201 }
1202 
1203 static int
dev_cmp(struct nf_queue_entry * entry,unsigned long ifindex)1204 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
1205 {
1206 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
1207 	int physinif, physoutif;
1208 
1209 	physinif = nf_bridge_get_physinif(entry->skb);
1210 	physoutif = nf_bridge_get_physoutif(entry->skb);
1211 
1212 	if (physinif == ifindex || physoutif == ifindex)
1213 		return 1;
1214 #endif
1215 	if (entry->state.in)
1216 		if (entry->state.in->ifindex == ifindex)
1217 			return 1;
1218 	if (entry->state.out)
1219 		if (entry->state.out->ifindex == ifindex)
1220 			return 1;
1221 
1222 	return 0;
1223 }
1224 
1225 /* drop all packets with either indev or outdev == ifindex from all queue
1226  * instances */
1227 static void
nfqnl_dev_drop(struct net * net,int ifindex)1228 nfqnl_dev_drop(struct net *net, int ifindex)
1229 {
1230 	int i;
1231 	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1232 
1233 	rcu_read_lock();
1234 
1235 	for (i = 0; i < INSTANCE_BUCKETS; i++) {
1236 		struct nfqnl_instance *inst;
1237 		struct hlist_head *head = &q->instance_table[i];
1238 
1239 		hlist_for_each_entry_rcu(inst, head, hlist)
1240 			nfqnl_flush(inst, dev_cmp, ifindex);
1241 	}
1242 
1243 	rcu_read_unlock();
1244 }
1245 
1246 static int
nfqnl_rcv_dev_event(struct notifier_block * this,unsigned long event,void * ptr)1247 nfqnl_rcv_dev_event(struct notifier_block *this,
1248 		    unsigned long event, void *ptr)
1249 {
1250 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1251 
1252 	/* Drop any packets associated with the downed device */
1253 	if (event == NETDEV_DOWN)
1254 		nfqnl_dev_drop(dev_net(dev), dev->ifindex);
1255 	return NOTIFY_DONE;
1256 }
1257 
1258 static struct notifier_block nfqnl_dev_notifier = {
1259 	.notifier_call	= nfqnl_rcv_dev_event,
1260 };
1261 
nfqnl_nf_hook_drop(struct net * net)1262 static void nfqnl_nf_hook_drop(struct net *net)
1263 {
1264 	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1265 	int i;
1266 
1267 	/* This function is also called on net namespace error unwind,
1268 	 * when pernet_ops->init() failed and ->exit() functions of the
1269 	 * previous pernet_ops gets called.
1270 	 *
1271 	 * This may result in a call to nfqnl_nf_hook_drop() before
1272 	 * struct nfnl_queue_net was allocated.
1273 	 */
1274 	if (!q)
1275 		return;
1276 
1277 	for (i = 0; i < INSTANCE_BUCKETS; i++) {
1278 		struct nfqnl_instance *inst;
1279 		struct hlist_head *head = &q->instance_table[i];
1280 
1281 		hlist_for_each_entry_rcu(inst, head, hlist)
1282 			nfqnl_flush(inst, NULL, 0);
1283 	}
1284 }
1285 
1286 static int
nfqnl_rcv_nl_event(struct notifier_block * this,unsigned long event,void * ptr)1287 nfqnl_rcv_nl_event(struct notifier_block *this,
1288 		   unsigned long event, void *ptr)
1289 {
1290 	struct netlink_notify *n = ptr;
1291 	struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
1292 
1293 	if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
1294 		int i;
1295 
1296 		/* destroy all instances for this portid */
1297 		spin_lock(&q->instances_lock);
1298 		for (i = 0; i < INSTANCE_BUCKETS; i++) {
1299 			struct hlist_node *t2;
1300 			struct nfqnl_instance *inst;
1301 			struct hlist_head *head = &q->instance_table[i];
1302 
1303 			hlist_for_each_entry_safe(inst, t2, head, hlist) {
1304 				if (n->portid == inst->peer_portid)
1305 					__instance_destroy(inst);
1306 			}
1307 		}
1308 		spin_unlock(&q->instances_lock);
1309 	}
1310 	return NOTIFY_DONE;
1311 }
1312 
1313 static struct notifier_block nfqnl_rtnl_notifier = {
1314 	.notifier_call	= nfqnl_rcv_nl_event,
1315 };
1316 
1317 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
1318 	[NFQA_VLAN_TCI]		= { .type = NLA_U16},
1319 	[NFQA_VLAN_PROTO]	= { .type = NLA_U16},
1320 };
1321 
1322 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
1323 	[NFQA_VERDICT_HDR]	= { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1324 	[NFQA_MARK]		= { .type = NLA_U32 },
1325 	[NFQA_PAYLOAD]		= { .type = NLA_UNSPEC },
1326 	[NFQA_CT]		= { .type = NLA_UNSPEC },
1327 	[NFQA_EXP]		= { .type = NLA_UNSPEC },
1328 	[NFQA_VLAN]		= { .type = NLA_NESTED },
1329 	[NFQA_PRIORITY]		= { .type = NLA_U32 },
1330 };
1331 
1332 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
1333 	[NFQA_VERDICT_HDR]	= { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1334 	[NFQA_MARK]		= { .type = NLA_U32 },
1335 	[NFQA_PRIORITY]		= { .type = NLA_U32 },
1336 };
1337 
1338 static struct nfqnl_instance *
verdict_instance_lookup(struct nfnl_queue_net * q,u16 queue_num,u32 nlportid)1339 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
1340 {
1341 	struct nfqnl_instance *queue;
1342 
1343 	queue = instance_lookup(q, queue_num);
1344 	if (!queue)
1345 		return ERR_PTR(-ENODEV);
1346 
1347 	if (queue->peer_portid != nlportid)
1348 		return ERR_PTR(-EPERM);
1349 
1350 	return queue;
1351 }
1352 
1353 static struct nfqnl_msg_verdict_hdr*
verdicthdr_get(const struct nlattr * const nfqa[])1354 verdicthdr_get(const struct nlattr * const nfqa[])
1355 {
1356 	struct nfqnl_msg_verdict_hdr *vhdr;
1357 	unsigned int verdict;
1358 
1359 	if (!nfqa[NFQA_VERDICT_HDR])
1360 		return NULL;
1361 
1362 	vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
1363 	verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
1364 	if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
1365 		return NULL;
1366 	return vhdr;
1367 }
1368 
nfq_id_after(unsigned int id,unsigned int max)1369 static int nfq_id_after(unsigned int id, unsigned int max)
1370 {
1371 	return (int)(id - max) > 0;
1372 }
1373 
nfqnl_recv_verdict_batch(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1374 static int nfqnl_recv_verdict_batch(struct sk_buff *skb,
1375 				    const struct nfnl_info *info,
1376 				    const struct nlattr * const nfqa[])
1377 {
1378 	struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1379 	u16 queue_num = ntohs(info->nfmsg->res_id);
1380 	struct nf_queue_entry *entry, *tmp;
1381 	struct nfqnl_msg_verdict_hdr *vhdr;
1382 	struct nfqnl_instance *queue;
1383 	unsigned int verdict, maxid;
1384 	LIST_HEAD(batch_list);
1385 
1386 	queue = verdict_instance_lookup(q, queue_num,
1387 					NETLINK_CB(skb).portid);
1388 	if (IS_ERR(queue))
1389 		return PTR_ERR(queue);
1390 
1391 	vhdr = verdicthdr_get(nfqa);
1392 	if (!vhdr)
1393 		return -EINVAL;
1394 
1395 	verdict = ntohl(vhdr->verdict);
1396 	maxid = ntohl(vhdr->id);
1397 
1398 	spin_lock_bh(&queue->lock);
1399 
1400 	list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
1401 		if (nfq_id_after(entry->id, maxid))
1402 			break;
1403 		__dequeue_entry(queue, entry);
1404 		list_add_tail(&entry->list, &batch_list);
1405 	}
1406 
1407 	spin_unlock_bh(&queue->lock);
1408 
1409 	if (list_empty(&batch_list))
1410 		return -ENOENT;
1411 
1412 	list_for_each_entry_safe(entry, tmp, &batch_list, list) {
1413 		if (nfqa[NFQA_MARK])
1414 			entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1415 
1416 		if (nfqa[NFQA_PRIORITY])
1417 			entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1418 
1419 		nfqnl_reinject(entry, verdict);
1420 	}
1421 	return 0;
1422 }
1423 
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)1424 static struct nf_conn *nfqnl_ct_parse(const struct nfnl_ct_hook *nfnl_ct,
1425 				      const struct nlmsghdr *nlh,
1426 				      const struct nlattr * const nfqa[],
1427 				      struct nf_queue_entry *entry,
1428 				      enum ip_conntrack_info *ctinfo)
1429 {
1430 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
1431 	struct nf_conn *ct;
1432 
1433 	ct = nf_ct_get(entry->skb, ctinfo);
1434 	if (ct == NULL)
1435 		return NULL;
1436 
1437 	if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
1438 		return NULL;
1439 
1440 	if (nfqa[NFQA_EXP])
1441 		nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
1442 				      NETLINK_CB(entry->skb).portid,
1443 				      nlmsg_report(nlh));
1444 	return ct;
1445 #else
1446 	return NULL;
1447 #endif
1448 }
1449 
nfqa_parse_bridge(struct nf_queue_entry * entry,const struct nlattr * const nfqa[])1450 static int nfqa_parse_bridge(struct nf_queue_entry *entry,
1451 			     const struct nlattr * const nfqa[])
1452 {
1453 	if (nfqa[NFQA_VLAN]) {
1454 		struct nlattr *tb[NFQA_VLAN_MAX + 1];
1455 		int err;
1456 
1457 		err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX,
1458 						  nfqa[NFQA_VLAN],
1459 						  nfqa_vlan_policy, NULL);
1460 		if (err < 0)
1461 			return err;
1462 
1463 		if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
1464 			return -EINVAL;
1465 
1466 		__vlan_hwaccel_put_tag(entry->skb,
1467 			nla_get_be16(tb[NFQA_VLAN_PROTO]),
1468 			ntohs(nla_get_be16(tb[NFQA_VLAN_TCI])));
1469 	}
1470 
1471 	if (nfqa[NFQA_L2HDR]) {
1472 		u32 mac_header_len = skb_mac_header_len(entry->skb);
1473 
1474 		if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
1475 			return -EINVAL;
1476 		else if (mac_header_len > 0)
1477 			memcpy(skb_mac_header(entry->skb),
1478 			       nla_data(nfqa[NFQA_L2HDR]),
1479 			       mac_header_len);
1480 	}
1481 
1482 	return 0;
1483 }
1484 
nfqnl_recv_verdict(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1485 static int nfqnl_recv_verdict(struct sk_buff *skb, const struct nfnl_info *info,
1486 			      const struct nlattr * const nfqa[])
1487 {
1488 	struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1489 	u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1490 	const struct nfnl_ct_hook *nfnl_ct;
1491 	struct nfqnl_msg_verdict_hdr *vhdr;
1492 	enum ip_conntrack_info ctinfo;
1493 	struct nfqnl_instance *queue;
1494 	struct nf_queue_entry *entry;
1495 	struct nf_conn *ct = NULL;
1496 	unsigned int verdict;
1497 	int err;
1498 
1499 	queue = verdict_instance_lookup(q, queue_num,
1500 					NETLINK_CB(skb).portid);
1501 	if (IS_ERR(queue))
1502 		return PTR_ERR(queue);
1503 
1504 	vhdr = verdicthdr_get(nfqa);
1505 	if (!vhdr)
1506 		return -EINVAL;
1507 
1508 	verdict = ntohl(vhdr->verdict);
1509 
1510 	entry = find_dequeue_entry(queue, ntohl(vhdr->id));
1511 	if (entry == NULL)
1512 		return -ENOENT;
1513 
1514 	/* rcu lock already held from nfnl->call_rcu. */
1515 	nfnl_ct = rcu_dereference(nfnl_ct_hook);
1516 
1517 	if (nfqa[NFQA_CT]) {
1518 		if (nfnl_ct != NULL)
1519 			ct = nfqnl_ct_parse(nfnl_ct, info->nlh, nfqa, entry,
1520 					    &ctinfo);
1521 	}
1522 
1523 	if (entry->state.pf == PF_BRIDGE) {
1524 		err = nfqa_parse_bridge(entry, nfqa);
1525 		if (err < 0) {
1526 			nfqnl_reinject(entry, NF_DROP);
1527 			return err;
1528 		}
1529 	}
1530 
1531 	if (nfqa[NFQA_PAYLOAD]) {
1532 		u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
1533 		int diff = payload_len - entry->skb->len;
1534 
1535 		if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
1536 				 payload_len, entry, diff) < 0)
1537 			verdict = NF_DROP;
1538 
1539 		if (ct && diff)
1540 			nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
1541 	}
1542 
1543 	if (nfqa[NFQA_MARK])
1544 		entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1545 
1546 	if (nfqa[NFQA_PRIORITY])
1547 		entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1548 
1549 	nfqnl_reinject(entry, verdict);
1550 	return 0;
1551 }
1552 
nfqnl_recv_unsupp(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const cda[])1553 static int nfqnl_recv_unsupp(struct sk_buff *skb, const struct nfnl_info *info,
1554 			     const struct nlattr * const cda[])
1555 {
1556 	return -ENOTSUPP;
1557 }
1558 
1559 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
1560 	[NFQA_CFG_CMD]		= { .len = sizeof(struct nfqnl_msg_config_cmd) },
1561 	[NFQA_CFG_PARAMS]	= { .len = sizeof(struct nfqnl_msg_config_params) },
1562 	[NFQA_CFG_QUEUE_MAXLEN]	= { .type = NLA_U32 },
1563 	[NFQA_CFG_MASK]		= { .type = NLA_U32 },
1564 	[NFQA_CFG_FLAGS]	= NLA_POLICY_MASK(NLA_BE32, NFQA_CFG_F_MAX - 1),
1565 };
1566 
1567 static const struct nf_queue_handler nfqh = {
1568 	.outfn		= nfqnl_enqueue_packet,
1569 	.nf_hook_drop	= nfqnl_nf_hook_drop,
1570 };
1571 
nfqnl_recv_config(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const nfqa[])1572 static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info,
1573 			     const struct nlattr * const nfqa[])
1574 {
1575 	struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1576 	u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1577 	struct nfqnl_msg_config_cmd *cmd = NULL;
1578 	struct nfqnl_instance *queue;
1579 	__u32 flags = 0, mask = 0;
1580 
1581 	WARN_ON_ONCE(!lockdep_nfnl_is_held(NFNL_SUBSYS_QUEUE));
1582 
1583 	if (nfqa[NFQA_CFG_CMD]) {
1584 		cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1585 
1586 		/* Obsolete commands without queue context */
1587 		switch (cmd->command) {
1588 		case NFQNL_CFG_CMD_PF_BIND: return 0;
1589 		case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1590 		}
1591 	}
1592 
1593 	/* Check if we support these flags in first place, dependencies should
1594 	 * be there too not to break atomicity.
1595 	 */
1596 	if (nfqa[NFQA_CFG_FLAGS]) {
1597 		if (!nfqa[NFQA_CFG_MASK]) {
1598 			/* A mask is needed to specify which flags are being
1599 			 * changed.
1600 			 */
1601 			return -EINVAL;
1602 		}
1603 
1604 		flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1605 		mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1606 
1607 		if (flags >= NFQA_CFG_F_MAX)
1608 			return -EOPNOTSUPP;
1609 
1610 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
1611 		if (flags & mask & NFQA_CFG_F_SECCTX)
1612 			return -EOPNOTSUPP;
1613 #endif
1614 		if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
1615 		    !rcu_access_pointer(nfnl_ct_hook)) {
1616 #ifdef CONFIG_MODULES
1617 			nfnl_unlock(NFNL_SUBSYS_QUEUE);
1618 			request_module("ip_conntrack_netlink");
1619 			nfnl_lock(NFNL_SUBSYS_QUEUE);
1620 			if (rcu_access_pointer(nfnl_ct_hook))
1621 				return -EAGAIN;
1622 #endif
1623 			return -EOPNOTSUPP;
1624 		}
1625 	}
1626 
1627 	/* Lookup queue under RCU. After peer_portid check (or for new queue
1628 	 * in BIND case), the queue is owned by the socket sending this message.
1629 	 * A socket cannot simultaneously send a message and close, so while
1630 	 * processing this CONFIG message, nfqnl_rcv_nl_event() (triggered by
1631 	 * socket close) cannot destroy this queue. Safe to use without RCU.
1632 	 */
1633 	rcu_read_lock();
1634 	queue = instance_lookup(q, queue_num);
1635 	if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1636 		rcu_read_unlock();
1637 		return -EPERM;
1638 	}
1639 	rcu_read_unlock();
1640 
1641 	if (cmd != NULL) {
1642 		switch (cmd->command) {
1643 		case NFQNL_CFG_CMD_BIND:
1644 			if (queue)
1645 				return -EBUSY;
1646 			queue = instance_create(q, queue_num, NETLINK_CB(skb).portid);
1647 			if (IS_ERR(queue))
1648 				return PTR_ERR(queue);
1649 			break;
1650 		case NFQNL_CFG_CMD_UNBIND:
1651 			if (!queue)
1652 				return -ENODEV;
1653 			instance_destroy(q, queue);
1654 			return 0;
1655 		case NFQNL_CFG_CMD_PF_BIND:
1656 		case NFQNL_CFG_CMD_PF_UNBIND:
1657 			break;
1658 		default:
1659 			return -EOPNOTSUPP;
1660 		}
1661 	}
1662 
1663 	if (!queue)
1664 		return -ENODEV;
1665 
1666 	if (nfqa[NFQA_CFG_PARAMS]) {
1667 		struct nfqnl_msg_config_params *params =
1668 			nla_data(nfqa[NFQA_CFG_PARAMS]);
1669 
1670 		nfqnl_set_mode(queue, params->copy_mode,
1671 				ntohl(params->copy_range));
1672 	}
1673 
1674 	if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1675 		__be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1676 
1677 		spin_lock_bh(&queue->lock);
1678 		queue->queue_maxlen = ntohl(*queue_maxlen);
1679 		spin_unlock_bh(&queue->lock);
1680 	}
1681 
1682 	if (nfqa[NFQA_CFG_FLAGS]) {
1683 		spin_lock_bh(&queue->lock);
1684 		queue->flags &= ~mask;
1685 		queue->flags |= flags & mask;
1686 		spin_unlock_bh(&queue->lock);
1687 	}
1688 
1689 	return 0;
1690 }
1691 
1692 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1693 	[NFQNL_MSG_PACKET]	= {
1694 		.call		= nfqnl_recv_unsupp,
1695 		.type		= NFNL_CB_RCU,
1696 		.attr_count	= NFQA_MAX,
1697 	},
1698 	[NFQNL_MSG_VERDICT]	= {
1699 		.call		= nfqnl_recv_verdict,
1700 		.type		= NFNL_CB_RCU,
1701 		.attr_count	= NFQA_MAX,
1702 		.policy		= nfqa_verdict_policy
1703 	},
1704 	[NFQNL_MSG_CONFIG]	= {
1705 		.call		= nfqnl_recv_config,
1706 		.type		= NFNL_CB_MUTEX,
1707 		.attr_count	= NFQA_CFG_MAX,
1708 		.policy		= nfqa_cfg_policy
1709 	},
1710 	[NFQNL_MSG_VERDICT_BATCH] = {
1711 		.call		= nfqnl_recv_verdict_batch,
1712 		.type		= NFNL_CB_RCU,
1713 		.attr_count	= NFQA_MAX,
1714 		.policy		= nfqa_verdict_batch_policy
1715 	},
1716 };
1717 
1718 static const struct nfnetlink_subsystem nfqnl_subsys = {
1719 	.name		= "nf_queue",
1720 	.subsys_id	= NFNL_SUBSYS_QUEUE,
1721 	.cb_count	= NFQNL_MSG_MAX,
1722 	.cb		= nfqnl_cb,
1723 };
1724 
1725 #ifdef CONFIG_PROC_FS
1726 struct iter_state {
1727 	struct seq_net_private p;
1728 	unsigned int bucket;
1729 };
1730 
get_first(struct seq_file * seq)1731 static struct hlist_node *get_first(struct seq_file *seq)
1732 {
1733 	struct iter_state *st = seq->private;
1734 	struct net *net;
1735 	struct nfnl_queue_net *q;
1736 
1737 	if (!st)
1738 		return NULL;
1739 
1740 	net = seq_file_net(seq);
1741 	q = nfnl_queue_pernet(net);
1742 	for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1743 		if (!hlist_empty(&q->instance_table[st->bucket]))
1744 			return q->instance_table[st->bucket].first;
1745 	}
1746 	return NULL;
1747 }
1748 
get_next(struct seq_file * seq,struct hlist_node * h)1749 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1750 {
1751 	struct iter_state *st = seq->private;
1752 	struct net *net = seq_file_net(seq);
1753 
1754 	h = h->next;
1755 	while (!h) {
1756 		struct nfnl_queue_net *q;
1757 
1758 		if (++st->bucket >= INSTANCE_BUCKETS)
1759 			return NULL;
1760 
1761 		q = nfnl_queue_pernet(net);
1762 		h = q->instance_table[st->bucket].first;
1763 	}
1764 	return h;
1765 }
1766 
get_idx(struct seq_file * seq,loff_t pos)1767 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1768 {
1769 	struct hlist_node *head;
1770 	head = get_first(seq);
1771 
1772 	if (head)
1773 		while (pos && (head = get_next(seq, head)))
1774 			pos--;
1775 	return pos ? NULL : head;
1776 }
1777 
seq_start(struct seq_file * s,loff_t * pos)1778 static void *seq_start(struct seq_file *s, loff_t *pos)
1779 	__acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1780 {
1781 	spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1782 	return get_idx(s, *pos);
1783 }
1784 
seq_next(struct seq_file * s,void * v,loff_t * pos)1785 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1786 {
1787 	(*pos)++;
1788 	return get_next(s, v);
1789 }
1790 
seq_stop(struct seq_file * s,void * v)1791 static void seq_stop(struct seq_file *s, void *v)
1792 	__releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1793 {
1794 	spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1795 }
1796 
seq_show(struct seq_file * s,void * v)1797 static int seq_show(struct seq_file *s, void *v)
1798 {
1799 	const struct nfqnl_instance *inst = v;
1800 
1801 	seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
1802 		   inst->queue_num,
1803 		   inst->peer_portid, inst->queue_total,
1804 		   inst->copy_mode, inst->copy_range,
1805 		   inst->queue_dropped, inst->queue_user_dropped,
1806 		   inst->id_sequence, 1);
1807 	return 0;
1808 }
1809 
1810 static const struct seq_operations nfqnl_seq_ops = {
1811 	.start	= seq_start,
1812 	.next	= seq_next,
1813 	.stop	= seq_stop,
1814 	.show	= seq_show,
1815 };
1816 #endif /* PROC_FS */
1817 
nfnl_queue_net_init(struct net * net)1818 static int __net_init nfnl_queue_net_init(struct net *net)
1819 {
1820 	unsigned int i;
1821 	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1822 
1823 	for (i = 0; i < INSTANCE_BUCKETS; i++)
1824 		INIT_HLIST_HEAD(&q->instance_table[i]);
1825 
1826 	spin_lock_init(&q->instances_lock);
1827 
1828 #ifdef CONFIG_PROC_FS
1829 	if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter,
1830 			&nfqnl_seq_ops, sizeof(struct iter_state)))
1831 		return -ENOMEM;
1832 #endif
1833 	return 0;
1834 }
1835 
nfnl_queue_net_exit(struct net * net)1836 static void __net_exit nfnl_queue_net_exit(struct net *net)
1837 {
1838 	struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1839 	unsigned int i;
1840 
1841 #ifdef CONFIG_PROC_FS
1842 	remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1843 #endif
1844 	for (i = 0; i < INSTANCE_BUCKETS; i++)
1845 		WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
1846 }
1847 
1848 static struct pernet_operations nfnl_queue_net_ops = {
1849 	.init		= nfnl_queue_net_init,
1850 	.exit		= nfnl_queue_net_exit,
1851 	.id		= &nfnl_queue_net_id,
1852 	.size		= sizeof(struct nfnl_queue_net),
1853 };
1854 
nfnetlink_queue_init(void)1855 static int __init nfnetlink_queue_init(void)
1856 {
1857 	int status;
1858 
1859 	nfq_cleanup_wq = alloc_ordered_workqueue("nfq_workqueue", 0);
1860 	if (!nfq_cleanup_wq)
1861 		return -ENOMEM;
1862 
1863 	status = register_pernet_subsys(&nfnl_queue_net_ops);
1864 	if (status < 0)
1865 		goto cleanup_pernet_subsys;
1866 
1867 	status = netlink_register_notifier(&nfqnl_rtnl_notifier);
1868 	if (status < 0)
1869 	       goto cleanup_rtnl_notifier;
1870 
1871 	status = register_netdevice_notifier(&nfqnl_dev_notifier);
1872 	if (status < 0)
1873 		goto cleanup_dev_notifier;
1874 
1875 	status = nfnetlink_subsys_register(&nfqnl_subsys);
1876 	if (status < 0)
1877 		goto cleanup_nfqnl_subsys;
1878 
1879 	nf_register_queue_handler(&nfqh);
1880 
1881 	return status;
1882 
1883 cleanup_nfqnl_subsys:
1884 	unregister_netdevice_notifier(&nfqnl_dev_notifier);
1885 cleanup_dev_notifier:
1886 	netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1887 cleanup_rtnl_notifier:
1888 	unregister_pernet_subsys(&nfnl_queue_net_ops);
1889 cleanup_pernet_subsys:
1890 	destroy_workqueue(nfq_cleanup_wq);
1891 	return status;
1892 }
1893 
nfnetlink_queue_fini(void)1894 static void __exit nfnetlink_queue_fini(void)
1895 {
1896 	nf_unregister_queue_handler();
1897 	unregister_netdevice_notifier(&nfqnl_dev_notifier);
1898 	nfnetlink_subsys_unregister(&nfqnl_subsys);
1899 	netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1900 	unregister_pernet_subsys(&nfnl_queue_net_ops);
1901 	destroy_workqueue(nfq_cleanup_wq);
1902 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1903 }
1904 
1905 MODULE_DESCRIPTION("netfilter packet queue handler");
1906 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1907 MODULE_LICENSE("GPL");
1908 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1909 
1910 module_init(nfnetlink_queue_init);
1911 module_exit(nfnetlink_queue_fini);
1912