[NETFILTER]: nf_queue: move list_head/skb/id to struct nf_info
[linux-3.10.git] / net / netfilter / nfnetlink_queue.c
1 /*
2  * This is a module which is used for queueing packets and communicating with
3  * userspace via nfetlink.
4  *
5  * (C) 2005 by Harald Welte <laforge@netfilter.org>
6  *
7  * Based on the old ipv4-only ip_queue.c:
8  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
9  * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  *
15  */
16 #include <linux/module.h>
17 #include <linux/skbuff.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/notifier.h>
21 #include <linux/netdevice.h>
22 #include <linux/netfilter.h>
23 #include <linux/proc_fs.h>
24 #include <linux/netfilter_ipv4.h>
25 #include <linux/netfilter_ipv6.h>
26 #include <linux/netfilter/nfnetlink.h>
27 #include <linux/netfilter/nfnetlink_queue.h>
28 #include <linux/list.h>
29 #include <net/sock.h>
30 #include <net/netfilter/nf_queue.h>
31
32 #include <asm/atomic.h>
33
34 #ifdef CONFIG_BRIDGE_NETFILTER
35 #include "../bridge/br_private.h"
36 #endif
37
38 #define NFQNL_QMAX_DEFAULT 1024
39
40 #if 0
41 #define QDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
42                                         __FILE__, __LINE__, __FUNCTION__,  \
43                                         ## args)
44 #else
45 #define QDEBUG(x, ...)
46 #endif
47
48 struct nfqnl_instance {
49         struct hlist_node hlist;                /* global list of queues */
50         atomic_t use;
51
52         int peer_pid;
53         unsigned int queue_maxlen;
54         unsigned int copy_range;
55         unsigned int queue_total;
56         unsigned int queue_dropped;
57         unsigned int queue_user_dropped;
58
59         atomic_t id_sequence;                   /* 'sequence' of pkt ids */
60
61         u_int16_t queue_num;                    /* number of this queue */
62         u_int8_t copy_mode;
63
64         spinlock_t lock;
65
66         struct list_head queue_list;            /* packets in queue */
67 };
68
69 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
70
71 static DEFINE_RWLOCK(instances_lock);
72
73 #define INSTANCE_BUCKETS        16
74 static struct hlist_head instance_table[INSTANCE_BUCKETS];
75
76 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
77 {
78         return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS;
79 }
80
81 static struct nfqnl_instance *
82 __instance_lookup(u_int16_t queue_num)
83 {
84         struct hlist_head *head;
85         struct hlist_node *pos;
86         struct nfqnl_instance *inst;
87
88         head = &instance_table[instance_hashfn(queue_num)];
89         hlist_for_each_entry(inst, pos, head, hlist) {
90                 if (inst->queue_num == queue_num)
91                         return inst;
92         }
93         return NULL;
94 }
95
96 static struct nfqnl_instance *
97 instance_lookup_get(u_int16_t queue_num)
98 {
99         struct nfqnl_instance *inst;
100
101         read_lock_bh(&instances_lock);
102         inst = __instance_lookup(queue_num);
103         if (inst)
104                 atomic_inc(&inst->use);
105         read_unlock_bh(&instances_lock);
106
107         return inst;
108 }
109
110 static void
111 instance_put(struct nfqnl_instance *inst)
112 {
113         if (inst && atomic_dec_and_test(&inst->use)) {
114                 QDEBUG("kfree(inst=%p)\n", inst);
115                 kfree(inst);
116         }
117 }
118
119 static struct nfqnl_instance *
120 instance_create(u_int16_t queue_num, int pid)
121 {
122         struct nfqnl_instance *inst;
123
124         QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid);
125
126         write_lock_bh(&instances_lock);
127         if (__instance_lookup(queue_num)) {
128                 inst = NULL;
129                 QDEBUG("aborting, instance already exists\n");
130                 goto out_unlock;
131         }
132
133         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
134         if (!inst)
135                 goto out_unlock;
136
137         inst->queue_num = queue_num;
138         inst->peer_pid = pid;
139         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
140         inst->copy_range = 0xfffff;
141         inst->copy_mode = NFQNL_COPY_NONE;
142         atomic_set(&inst->id_sequence, 0);
143         /* needs to be two, since we _put() after creation */
144         atomic_set(&inst->use, 2);
145         spin_lock_init(&inst->lock);
146         INIT_LIST_HEAD(&inst->queue_list);
147
148         if (!try_module_get(THIS_MODULE))
149                 goto out_free;
150
151         hlist_add_head(&inst->hlist,
152                        &instance_table[instance_hashfn(queue_num)]);
153
154         write_unlock_bh(&instances_lock);
155
156         QDEBUG("successfully created new instance\n");
157
158         return inst;
159
160 out_free:
161         kfree(inst);
162 out_unlock:
163         write_unlock_bh(&instances_lock);
164         return NULL;
165 }
166
167 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
168                         unsigned long data);
169
170 static void
171 _instance_destroy2(struct nfqnl_instance *inst, int lock)
172 {
173         /* first pull it out of the global list */
174         if (lock)
175                 write_lock_bh(&instances_lock);
176
177         QDEBUG("removing instance %p (queuenum=%u) from hash\n",
178                 inst, inst->queue_num);
179         hlist_del(&inst->hlist);
180
181         if (lock)
182                 write_unlock_bh(&instances_lock);
183
184         /* then flush all pending skbs from the queue */
185         nfqnl_flush(inst, NULL, 0);
186
187         /* and finally put the refcount */
188         instance_put(inst);
189
190         module_put(THIS_MODULE);
191 }
192
193 static inline void
194 __instance_destroy(struct nfqnl_instance *inst)
195 {
196         _instance_destroy2(inst, 0);
197 }
198
199 static inline void
200 instance_destroy(struct nfqnl_instance *inst)
201 {
202         _instance_destroy2(inst, 1);
203 }
204
205
206
207 static void
208 issue_verdict(struct nf_queue_entry *entry, int verdict)
209 {
210         QDEBUG("entering for entry %p, verdict %u\n", entry, verdict);
211
212         /* TCP input path (and probably other bits) assume to be called
213          * from softirq context, not from syscall, like issue_verdict is
214          * called.  TCP input path deadlocks with locks taken from timer
215          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
216
217         local_bh_disable();
218         nf_reinject(entry, verdict);
219         local_bh_enable();
220 }
221
222 static inline void
223 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
224 {
225        list_add_tail(&entry->list, &queue->queue_list);
226        queue->queue_total++;
227 }
228
229 static inline int
230 __nfqnl_set_mode(struct nfqnl_instance *queue,
231                  unsigned char mode, unsigned int range)
232 {
233         int status = 0;
234
235         switch (mode) {
236         case NFQNL_COPY_NONE:
237         case NFQNL_COPY_META:
238                 queue->copy_mode = mode;
239                 queue->copy_range = 0;
240                 break;
241
242         case NFQNL_COPY_PACKET:
243                 queue->copy_mode = mode;
244                 /* we're using struct nlattr which has 16bit nla_len */
245                 if (range > 0xffff)
246                         queue->copy_range = 0xffff;
247                 else
248                         queue->copy_range = range;
249                 break;
250
251         default:
252                 status = -EINVAL;
253
254         }
255         return status;
256 }
257
258 static struct nf_queue_entry *
259 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
260 {
261         struct nf_queue_entry *entry = NULL, *i;
262
263         spin_lock_bh(&queue->lock);
264
265         list_for_each_entry(i, &queue->queue_list, list) {
266                 if (i->id == id) {
267                         entry = i;
268                         break;
269                 }
270         }
271
272         if (entry) {
273                 list_del(&entry->list);
274                 queue->queue_total--;
275         }
276
277         spin_unlock_bh(&queue->lock);
278
279         return entry;
280 }
281
282 static void
283 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
284 {
285         struct nf_queue_entry *entry, *next;
286
287         spin_lock_bh(&queue->lock);
288         list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
289                 if (!cmpfn || cmpfn(entry, data)) {
290                         list_del(&entry->list);
291                         queue->queue_total--;
292                         issue_verdict(entry, NF_DROP);
293                 }
294         }
295         spin_unlock_bh(&queue->lock);
296 }
297
298 static struct sk_buff *
299 nfqnl_build_packet_message(struct nfqnl_instance *queue,
300                            struct nf_queue_entry *entry, int *errp)
301 {
302         sk_buff_data_t old_tail;
303         size_t size;
304         size_t data_len = 0;
305         struct sk_buff *skb;
306         struct nfqnl_msg_packet_hdr pmsg;
307         struct nlmsghdr *nlh;
308         struct nfgenmsg *nfmsg;
309         struct sk_buff *entskb = entry->skb;
310         struct net_device *indev;
311         struct net_device *outdev;
312         __be32 tmp_uint;
313
314         QDEBUG("entered\n");
315
316         size =    NLMSG_ALIGN(sizeof(struct nfgenmsg))
317                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
318                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
319                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
320 #ifdef CONFIG_BRIDGE_NETFILTER
321                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
322                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
323 #endif
324                 + nla_total_size(sizeof(u_int32_t))     /* mark */
325                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
326                 + nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
327
328         outdev = entry->outdev;
329
330         spin_lock_bh(&queue->lock);
331
332         switch (queue->copy_mode) {
333         case NFQNL_COPY_META:
334         case NFQNL_COPY_NONE:
335                 data_len = 0;
336                 break;
337
338         case NFQNL_COPY_PACKET:
339                 if ((entskb->ip_summed == CHECKSUM_PARTIAL ||
340                      entskb->ip_summed == CHECKSUM_COMPLETE) &&
341                     (*errp = skb_checksum_help(entskb))) {
342                         spin_unlock_bh(&queue->lock);
343                         return NULL;
344                 }
345                 if (queue->copy_range == 0
346                     || queue->copy_range > entskb->len)
347                         data_len = entskb->len;
348                 else
349                         data_len = queue->copy_range;
350
351                 size += nla_total_size(data_len);
352                 break;
353
354         default:
355                 *errp = -EINVAL;
356                 spin_unlock_bh(&queue->lock);
357                 return NULL;
358         }
359
360         spin_unlock_bh(&queue->lock);
361
362         skb = alloc_skb(size, GFP_ATOMIC);
363         if (!skb)
364                 goto nlmsg_failure;
365
366         old_tail = skb->tail;
367         nlh = NLMSG_PUT(skb, 0, 0,
368                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
369                         sizeof(struct nfgenmsg));
370         nfmsg = NLMSG_DATA(nlh);
371         nfmsg->nfgen_family = entry->pf;
372         nfmsg->version = NFNETLINK_V0;
373         nfmsg->res_id = htons(queue->queue_num);
374
375         pmsg.packet_id          = htonl(entry->id);
376         pmsg.hw_protocol        = entskb->protocol;
377         pmsg.hook               = entry->hook;
378
379         NLA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg);
380
381         indev = entry->indev;
382         if (indev) {
383                 tmp_uint = htonl(indev->ifindex);
384 #ifndef CONFIG_BRIDGE_NETFILTER
385                 NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint);
386 #else
387                 if (entry->pf == PF_BRIDGE) {
388                         /* Case 1: indev is physical input device, we need to
389                          * look for bridge group (when called from
390                          * netfilter_bridge) */
391                         NLA_PUT(skb, NFQA_IFINDEX_PHYSINDEV, sizeof(tmp_uint),
392                                 &tmp_uint);
393                         /* this is the bridge group "brX" */
394                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
395                         NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
396                                 &tmp_uint);
397                 } else {
398                         /* Case 2: indev is bridge group, we need to look for
399                          * physical device (when called from ipv4) */
400                         NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
401                                 &tmp_uint);
402                         if (entskb->nf_bridge
403                             && entskb->nf_bridge->physindev) {
404                                 tmp_uint = htonl(entskb->nf_bridge->physindev->ifindex);
405                                 NLA_PUT(skb, NFQA_IFINDEX_PHYSINDEV,
406                                         sizeof(tmp_uint), &tmp_uint);
407                         }
408                 }
409 #endif
410         }
411
412         if (outdev) {
413                 tmp_uint = htonl(outdev->ifindex);
414 #ifndef CONFIG_BRIDGE_NETFILTER
415                 NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint);
416 #else
417                 if (entry->pf == PF_BRIDGE) {
418                         /* Case 1: outdev is physical output device, we need to
419                          * look for bridge group (when called from
420                          * netfilter_bridge) */
421                         NLA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV, sizeof(tmp_uint),
422                                 &tmp_uint);
423                         /* this is the bridge group "brX" */
424                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
425                         NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
426                                 &tmp_uint);
427                 } else {
428                         /* Case 2: outdev is bridge group, we need to look for
429                          * physical output device (when called from ipv4) */
430                         NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
431                                 &tmp_uint);
432                         if (entskb->nf_bridge
433                             && entskb->nf_bridge->physoutdev) {
434                                 tmp_uint = htonl(entskb->nf_bridge->physoutdev->ifindex);
435                                 NLA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV,
436                                         sizeof(tmp_uint), &tmp_uint);
437                         }
438                 }
439 #endif
440         }
441
442         if (entskb->mark) {
443                 tmp_uint = htonl(entskb->mark);
444                 NLA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
445         }
446
447         if (indev && entskb->dev) {
448                 struct nfqnl_msg_packet_hw phw;
449                 int len = dev_parse_header(entskb, phw.hw_addr);
450                 if (len) {
451                         phw.hw_addrlen = htons(len);
452                         NLA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
453                 }
454         }
455
456         if (entskb->tstamp.tv64) {
457                 struct nfqnl_msg_packet_timestamp ts;
458                 struct timeval tv = ktime_to_timeval(entskb->tstamp);
459                 ts.sec = cpu_to_be64(tv.tv_sec);
460                 ts.usec = cpu_to_be64(tv.tv_usec);
461
462                 NLA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
463         }
464
465         if (data_len) {
466                 struct nlattr *nla;
467                 int size = nla_attr_size(data_len);
468
469                 if (skb_tailroom(skb) < nla_total_size(data_len)) {
470                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
471                         goto nlmsg_failure;
472                 }
473
474                 nla = (struct nlattr *)skb_put(skb, nla_total_size(data_len));
475                 nla->nla_type = NFQA_PAYLOAD;
476                 nla->nla_len = size;
477
478                 if (skb_copy_bits(entskb, 0, nla_data(nla), data_len))
479                         BUG();
480         }
481
482         nlh->nlmsg_len = skb->tail - old_tail;
483         return skb;
484
485 nlmsg_failure:
486 nla_put_failure:
487         if (skb)
488                 kfree_skb(skb);
489         *errp = -EINVAL;
490         if (net_ratelimit())
491                 printk(KERN_ERR "nf_queue: error creating packet message\n");
492         return NULL;
493 }
494
495 static int
496 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
497 {
498         int status = -EINVAL;
499         struct sk_buff *nskb;
500         struct nfqnl_instance *queue;
501
502         QDEBUG("entered\n");
503
504         queue = instance_lookup_get(queuenum);
505         if (!queue) {
506                 QDEBUG("no queue instance matching\n");
507                 return -EINVAL;
508         }
509
510         if (queue->copy_mode == NFQNL_COPY_NONE) {
511                 QDEBUG("mode COPY_NONE, aborting\n");
512                 status = -EAGAIN;
513                 goto err_out_put;
514         }
515
516         entry->id = atomic_inc_return(&queue->id_sequence);
517
518         nskb = nfqnl_build_packet_message(queue, entry, &status);
519         if (nskb == NULL)
520                 goto err_out_put;
521
522         spin_lock_bh(&queue->lock);
523
524         if (!queue->peer_pid)
525                 goto err_out_free_nskb;
526
527         if (queue->queue_total >= queue->queue_maxlen) {
528                 queue->queue_dropped++;
529                 status = -ENOSPC;
530                 if (net_ratelimit())
531                           printk(KERN_WARNING "nf_queue: full at %d entries, "
532                                  "dropping packets(s). Dropped: %d\n",
533                                  queue->queue_total, queue->queue_dropped);
534                 goto err_out_free_nskb;
535         }
536
537         /* nfnetlink_unicast will either free the nskb or add it to a socket */
538         status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
539         if (status < 0) {
540                 queue->queue_user_dropped++;
541                 goto err_out_unlock;
542         }
543
544         __enqueue_entry(queue, entry);
545
546         spin_unlock_bh(&queue->lock);
547         instance_put(queue);
548         return status;
549
550 err_out_free_nskb:
551         kfree_skb(nskb);
552
553 err_out_unlock:
554         spin_unlock_bh(&queue->lock);
555
556 err_out_put:
557         instance_put(queue);
558         return status;
559 }
560
561 static int
562 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e)
563 {
564         int diff;
565         int err;
566
567         diff = data_len - e->skb->len;
568         if (diff < 0) {
569                 if (pskb_trim(e->skb, data_len))
570                         return -ENOMEM;
571         } else if (diff > 0) {
572                 if (data_len > 0xFFFF)
573                         return -EINVAL;
574                 if (diff > skb_tailroom(e->skb)) {
575                         err = pskb_expand_head(e->skb, 0,
576                                                diff - skb_tailroom(e->skb),
577                                                GFP_ATOMIC);
578                         if (err) {
579                                 printk(KERN_WARNING "nf_queue: OOM "
580                                       "in mangle, dropping packet\n");
581                                 return err;
582                         }
583                 }
584                 skb_put(e->skb, diff);
585         }
586         if (!skb_make_writable(e->skb, data_len))
587                 return -ENOMEM;
588         skb_copy_to_linear_data(e->skb, data, data_len);
589         e->skb->ip_summed = CHECKSUM_NONE;
590         return 0;
591 }
592
593 static int
594 nfqnl_set_mode(struct nfqnl_instance *queue,
595                unsigned char mode, unsigned int range)
596 {
597         int status;
598
599         spin_lock_bh(&queue->lock);
600         status = __nfqnl_set_mode(queue, mode, range);
601         spin_unlock_bh(&queue->lock);
602
603         return status;
604 }
605
606 static int
607 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
608 {
609         if (entry->indev)
610                 if (entry->indev->ifindex == ifindex)
611                         return 1;
612         if (entry->outdev)
613                 if (entry->outdev->ifindex == ifindex)
614                         return 1;
615 #ifdef CONFIG_BRIDGE_NETFILTER
616         if (entry->skb->nf_bridge) {
617                 if (entry->skb->nf_bridge->physindev &&
618                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
619                         return 1;
620                 if (entry->skb->nf_bridge->physoutdev &&
621                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
622                         return 1;
623         }
624 #endif
625         return 0;
626 }
627
628 /* drop all packets with either indev or outdev == ifindex from all queue
629  * instances */
630 static void
631 nfqnl_dev_drop(int ifindex)
632 {
633         int i;
634
635         QDEBUG("entering for ifindex %u\n", ifindex);
636
637         /* this only looks like we have to hold the readlock for a way too long
638          * time, issue_verdict(),  nf_reinject(), ... - but we always only
639          * issue NF_DROP, which is processed directly in nf_reinject() */
640         read_lock_bh(&instances_lock);
641
642         for  (i = 0; i < INSTANCE_BUCKETS; i++) {
643                 struct hlist_node *tmp;
644                 struct nfqnl_instance *inst;
645                 struct hlist_head *head = &instance_table[i];
646
647                 hlist_for_each_entry(inst, tmp, head, hlist)
648                         nfqnl_flush(inst, dev_cmp, ifindex);
649         }
650
651         read_unlock_bh(&instances_lock);
652 }
653
654 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
655
656 static int
657 nfqnl_rcv_dev_event(struct notifier_block *this,
658                     unsigned long event, void *ptr)
659 {
660         struct net_device *dev = ptr;
661
662         if (dev->nd_net != &init_net)
663                 return NOTIFY_DONE;
664
665         /* Drop any packets associated with the downed device */
666         if (event == NETDEV_DOWN)
667                 nfqnl_dev_drop(dev->ifindex);
668         return NOTIFY_DONE;
669 }
670
671 static struct notifier_block nfqnl_dev_notifier = {
672         .notifier_call  = nfqnl_rcv_dev_event,
673 };
674
675 static int
676 nfqnl_rcv_nl_event(struct notifier_block *this,
677                    unsigned long event, void *ptr)
678 {
679         struct netlink_notify *n = ptr;
680
681         if (event == NETLINK_URELEASE &&
682             n->protocol == NETLINK_NETFILTER && n->pid) {
683                 int i;
684
685                 /* destroy all instances for this pid */
686                 write_lock_bh(&instances_lock);
687                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
688                         struct hlist_node *tmp, *t2;
689                         struct nfqnl_instance *inst;
690                         struct hlist_head *head = &instance_table[i];
691
692                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
693                                 if ((n->net == &init_net) &&
694                                     (n->pid == inst->peer_pid))
695                                         __instance_destroy(inst);
696                         }
697                 }
698                 write_unlock_bh(&instances_lock);
699         }
700         return NOTIFY_DONE;
701 }
702
703 static struct notifier_block nfqnl_rtnl_notifier = {
704         .notifier_call  = nfqnl_rcv_nl_event,
705 };
706
707 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
708         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
709         [NFQA_MARK]             = { .type = NLA_U32 },
710         [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
711 };
712
713 static int
714 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
715                    struct nlmsghdr *nlh, struct nlattr *nfqa[])
716 {
717         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
718         u_int16_t queue_num = ntohs(nfmsg->res_id);
719
720         struct nfqnl_msg_verdict_hdr *vhdr;
721         struct nfqnl_instance *queue;
722         unsigned int verdict;
723         struct nf_queue_entry *entry;
724         int err;
725
726         queue = instance_lookup_get(queue_num);
727         if (!queue)
728                 return -ENODEV;
729
730         if (queue->peer_pid != NETLINK_CB(skb).pid) {
731                 err = -EPERM;
732                 goto err_out_put;
733         }
734
735         if (!nfqa[NFQA_VERDICT_HDR]) {
736                 err = -EINVAL;
737                 goto err_out_put;
738         }
739
740         vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
741         verdict = ntohl(vhdr->verdict);
742
743         if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
744                 err = -EINVAL;
745                 goto err_out_put;
746         }
747
748         entry = find_dequeue_entry(queue, ntohl(vhdr->id));
749         if (entry == NULL) {
750                 err = -ENOENT;
751                 goto err_out_put;
752         }
753
754         if (nfqa[NFQA_PAYLOAD]) {
755                 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
756                                  nla_len(nfqa[NFQA_PAYLOAD]), entry) < 0)
757                         verdict = NF_DROP;
758         }
759
760         if (nfqa[NFQA_MARK])
761                 entry->skb->mark = ntohl(*(__be32 *)
762                                          nla_data(nfqa[NFQA_MARK]));
763
764         issue_verdict(entry, verdict);
765         instance_put(queue);
766         return 0;
767
768 err_out_put:
769         instance_put(queue);
770         return err;
771 }
772
773 static int
774 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
775                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
776 {
777         return -ENOTSUPP;
778 }
779
780 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
781         [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
782         [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
783 };
784
785 static const struct nf_queue_handler nfqh = {
786         .name   = "nf_queue",
787         .outfn  = &nfqnl_enqueue_packet,
788 };
789
790 static int
791 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
792                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
793 {
794         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
795         u_int16_t queue_num = ntohs(nfmsg->res_id);
796         struct nfqnl_instance *queue;
797         int ret = 0;
798
799         QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
800
801         queue = instance_lookup_get(queue_num);
802         if (nfqa[NFQA_CFG_CMD]) {
803                 struct nfqnl_msg_config_cmd *cmd;
804                 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
805                 QDEBUG("found CFG_CMD\n");
806
807                 switch (cmd->command) {
808                 case NFQNL_CFG_CMD_BIND:
809                         if (queue)
810                                 return -EBUSY;
811
812                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
813                         if (!queue)
814                                 return -EINVAL;
815                         break;
816                 case NFQNL_CFG_CMD_UNBIND:
817                         if (!queue)
818                                 return -ENODEV;
819
820                         if (queue->peer_pid != NETLINK_CB(skb).pid) {
821                                 ret = -EPERM;
822                                 goto out_put;
823                         }
824
825                         instance_destroy(queue);
826                         break;
827                 case NFQNL_CFG_CMD_PF_BIND:
828                         QDEBUG("registering queue handler for pf=%u\n",
829                                 ntohs(cmd->pf));
830                         ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
831                         break;
832                 case NFQNL_CFG_CMD_PF_UNBIND:
833                         QDEBUG("unregistering queue handler for pf=%u\n",
834                                 ntohs(cmd->pf));
835                         ret = nf_unregister_queue_handler(ntohs(cmd->pf), &nfqh);
836                         break;
837                 default:
838                         ret = -EINVAL;
839                         break;
840                 }
841         } else {
842                 if (!queue) {
843                         QDEBUG("no config command, and no instance ENOENT\n");
844                         ret = -ENOENT;
845                         goto out_put;
846                 }
847
848                 if (queue->peer_pid != NETLINK_CB(skb).pid) {
849                         QDEBUG("no config command, and wrong pid\n");
850                         ret = -EPERM;
851                         goto out_put;
852                 }
853         }
854
855         if (nfqa[NFQA_CFG_PARAMS]) {
856                 struct nfqnl_msg_config_params *params;
857
858                 if (!queue) {
859                         ret = -ENOENT;
860                         goto out_put;
861                 }
862                 params = nla_data(nfqa[NFQA_CFG_PARAMS]);
863                 nfqnl_set_mode(queue, params->copy_mode,
864                                 ntohl(params->copy_range));
865         }
866
867         if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
868                 __be32 *queue_maxlen;
869                 queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
870                 spin_lock_bh(&queue->lock);
871                 queue->queue_maxlen = ntohl(*queue_maxlen);
872                 spin_unlock_bh(&queue->lock);
873         }
874
875 out_put:
876         instance_put(queue);
877         return ret;
878 }
879
880 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
881         [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
882                                     .attr_count = NFQA_MAX, },
883         [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
884                                     .attr_count = NFQA_MAX,
885                                     .policy = nfqa_verdict_policy },
886         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
887                                     .attr_count = NFQA_CFG_MAX,
888                                     .policy = nfqa_cfg_policy },
889 };
890
891 static const struct nfnetlink_subsystem nfqnl_subsys = {
892         .name           = "nf_queue",
893         .subsys_id      = NFNL_SUBSYS_QUEUE,
894         .cb_count       = NFQNL_MSG_MAX,
895         .cb             = nfqnl_cb,
896 };
897
898 #ifdef CONFIG_PROC_FS
899 struct iter_state {
900         unsigned int bucket;
901 };
902
903 static struct hlist_node *get_first(struct seq_file *seq)
904 {
905         struct iter_state *st = seq->private;
906
907         if (!st)
908                 return NULL;
909
910         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
911                 if (!hlist_empty(&instance_table[st->bucket]))
912                         return instance_table[st->bucket].first;
913         }
914         return NULL;
915 }
916
917 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
918 {
919         struct iter_state *st = seq->private;
920
921         h = h->next;
922         while (!h) {
923                 if (++st->bucket >= INSTANCE_BUCKETS)
924                         return NULL;
925
926                 h = instance_table[st->bucket].first;
927         }
928         return h;
929 }
930
931 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
932 {
933         struct hlist_node *head;
934         head = get_first(seq);
935
936         if (head)
937                 while (pos && (head = get_next(seq, head)))
938                         pos--;
939         return pos ? NULL : head;
940 }
941
942 static void *seq_start(struct seq_file *seq, loff_t *pos)
943 {
944         read_lock_bh(&instances_lock);
945         return get_idx(seq, *pos);
946 }
947
948 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
949 {
950         (*pos)++;
951         return get_next(s, v);
952 }
953
954 static void seq_stop(struct seq_file *s, void *v)
955 {
956         read_unlock_bh(&instances_lock);
957 }
958
959 static int seq_show(struct seq_file *s, void *v)
960 {
961         const struct nfqnl_instance *inst = v;
962
963         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
964                           inst->queue_num,
965                           inst->peer_pid, inst->queue_total,
966                           inst->copy_mode, inst->copy_range,
967                           inst->queue_dropped, inst->queue_user_dropped,
968                           atomic_read(&inst->id_sequence),
969                           atomic_read(&inst->use));
970 }
971
972 static const struct seq_operations nfqnl_seq_ops = {
973         .start  = seq_start,
974         .next   = seq_next,
975         .stop   = seq_stop,
976         .show   = seq_show,
977 };
978
979 static int nfqnl_open(struct inode *inode, struct file *file)
980 {
981         return seq_open_private(file, &nfqnl_seq_ops,
982                         sizeof(struct iter_state));
983 }
984
985 static const struct file_operations nfqnl_file_ops = {
986         .owner   = THIS_MODULE,
987         .open    = nfqnl_open,
988         .read    = seq_read,
989         .llseek  = seq_lseek,
990         .release = seq_release_private,
991 };
992
993 #endif /* PROC_FS */
994
995 static int __init nfnetlink_queue_init(void)
996 {
997         int i, status = -ENOMEM;
998 #ifdef CONFIG_PROC_FS
999         struct proc_dir_entry *proc_nfqueue;
1000 #endif
1001
1002         for (i = 0; i < INSTANCE_BUCKETS; i++)
1003                 INIT_HLIST_HEAD(&instance_table[i]);
1004
1005         netlink_register_notifier(&nfqnl_rtnl_notifier);
1006         status = nfnetlink_subsys_register(&nfqnl_subsys);
1007         if (status < 0) {
1008                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1009                 goto cleanup_netlink_notifier;
1010         }
1011
1012 #ifdef CONFIG_PROC_FS
1013         proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
1014                                          proc_net_netfilter);
1015         if (!proc_nfqueue)
1016                 goto cleanup_subsys;
1017         proc_nfqueue->proc_fops = &nfqnl_file_ops;
1018 #endif
1019
1020         register_netdevice_notifier(&nfqnl_dev_notifier);
1021         return status;
1022
1023 #ifdef CONFIG_PROC_FS
1024 cleanup_subsys:
1025         nfnetlink_subsys_unregister(&nfqnl_subsys);
1026 #endif
1027 cleanup_netlink_notifier:
1028         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1029         return status;
1030 }
1031
1032 static void __exit nfnetlink_queue_fini(void)
1033 {
1034         nf_unregister_queue_handlers(&nfqh);
1035         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1036 #ifdef CONFIG_PROC_FS
1037         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1038 #endif
1039         nfnetlink_subsys_unregister(&nfqnl_subsys);
1040         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1041 }
1042
1043 MODULE_DESCRIPTION("netfilter packet queue handler");
1044 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1045 MODULE_LICENSE("GPL");
1046 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1047
1048 module_init(nfnetlink_queue_init);
1049 module_exit(nfnetlink_queue_fini);