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Linux/net/netfilter/nfnetlink_queue.c

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

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