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