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Linux/net/netfilter/nfnetlink_queue.c

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

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