[NETFILTER]: attribute count is an attribute of message type, not subsytem
[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
31 #include <asm/atomic.h>
32
33 #define NFQNL_QMAX_DEFAULT 1024
34
35 #if 0
36 #define QDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
37                                         __FILE__, __LINE__, __FUNCTION__,  \
38                                         ## args)
39 #else
40 #define QDEBUG(x, ...)
41 #endif
42
43 struct nfqnl_queue_entry {
44         struct list_head list;
45         struct nf_info *info;
46         struct sk_buff *skb;
47         unsigned int id;
48 };
49
50 struct nfqnl_instance {
51         struct hlist_node hlist;                /* global list of queues */
52         atomic_t use;
53
54         int peer_pid;
55         unsigned int queue_maxlen;
56         unsigned int copy_range;
57         unsigned int queue_total;
58         unsigned int queue_dropped;
59         unsigned int queue_user_dropped;
60
61         atomic_t id_sequence;                   /* 'sequence' of pkt ids */
62
63         u_int16_t queue_num;                    /* number of this queue */
64         u_int8_t copy_mode;
65
66         spinlock_t lock;
67
68         struct list_head queue_list;            /* packets in queue */
69 };
70
71 typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long);
72
73 static DEFINE_RWLOCK(instances_lock);
74
75 u_int64_t htonll(u_int64_t in)
76 {
77         u_int64_t out;
78         int i;
79
80         for (i = 0; i < sizeof(u_int64_t); i++)
81                 ((u_int8_t *)&out)[sizeof(u_int64_t)-1] = ((u_int8_t *)&in)[i];
82
83         return out;
84 }
85
86 #define INSTANCE_BUCKETS        16
87 static struct hlist_head instance_table[INSTANCE_BUCKETS];
88
89 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
90 {
91         return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS;
92 }
93
94 static struct nfqnl_instance *
95 __instance_lookup(u_int16_t queue_num)
96 {
97         struct hlist_head *head;
98         struct hlist_node *pos;
99         struct nfqnl_instance *inst;
100
101         head = &instance_table[instance_hashfn(queue_num)];
102         hlist_for_each_entry(inst, pos, head, hlist) {
103                 if (inst->queue_num == queue_num)
104                         return inst;
105         }
106         return NULL;
107 }
108
109 static struct nfqnl_instance *
110 instance_lookup_get(u_int16_t queue_num)
111 {
112         struct nfqnl_instance *inst;
113
114         read_lock_bh(&instances_lock);
115         inst = __instance_lookup(queue_num);
116         if (inst)
117                 atomic_inc(&inst->use);
118         read_unlock_bh(&instances_lock);
119
120         return inst;
121 }
122
123 static void
124 instance_put(struct nfqnl_instance *inst)
125 {
126         if (inst && atomic_dec_and_test(&inst->use)) {
127                 QDEBUG("kfree(inst=%p)\n", inst);
128                 kfree(inst);
129         }
130 }
131
132 static struct nfqnl_instance *
133 instance_create(u_int16_t queue_num, int pid)
134 {
135         struct nfqnl_instance *inst;
136
137         QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid);
138
139         write_lock_bh(&instances_lock); 
140         if (__instance_lookup(queue_num)) {
141                 inst = NULL;
142                 QDEBUG("aborting, instance already exists\n");
143                 goto out_unlock;
144         }
145
146         inst = kmalloc(sizeof(*inst), GFP_ATOMIC);
147         if (!inst)
148                 goto out_unlock;
149
150         memset(inst, 0, sizeof(*inst));
151         inst->queue_num = queue_num;
152         inst->peer_pid = pid;
153         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
154         inst->copy_range = 0xfffff;
155         inst->copy_mode = NFQNL_COPY_NONE;
156         atomic_set(&inst->id_sequence, 0);
157         /* needs to be two, since we _put() after creation */
158         atomic_set(&inst->use, 2);
159         inst->lock = SPIN_LOCK_UNLOCKED;
160         INIT_LIST_HEAD(&inst->queue_list);
161
162         if (!try_module_get(THIS_MODULE))
163                 goto out_free;
164
165         hlist_add_head(&inst->hlist, 
166                        &instance_table[instance_hashfn(queue_num)]);
167
168         write_unlock_bh(&instances_lock);
169
170         QDEBUG("successfully created new instance\n");
171
172         return inst;
173
174 out_free:
175         kfree(inst);
176 out_unlock:
177         write_unlock_bh(&instances_lock);
178         return NULL;
179 }
180
181 static void nfqnl_flush(struct nfqnl_instance *queue, int verdict);
182
183 static void
184 _instance_destroy2(struct nfqnl_instance *inst, int lock)
185 {
186         /* first pull it out of the global list */
187         if (lock)
188                 write_lock_bh(&instances_lock);
189
190         QDEBUG("removing instance %p (queuenum=%u) from hash\n",
191                 inst, inst->queue_num);
192         hlist_del(&inst->hlist);
193
194         if (lock)
195                 write_unlock_bh(&instances_lock);
196
197         /* then flush all pending skbs from the queue */
198         nfqnl_flush(inst, NF_DROP);
199
200         /* and finally put the refcount */
201         instance_put(inst);
202
203         module_put(THIS_MODULE);
204 }
205
206 static inline void
207 __instance_destroy(struct nfqnl_instance *inst)
208 {
209         _instance_destroy2(inst, 0);
210 }
211
212 static inline void
213 instance_destroy(struct nfqnl_instance *inst)
214 {
215         _instance_destroy2(inst, 1);
216 }
217
218
219
220 static void
221 issue_verdict(struct nfqnl_queue_entry *entry, int verdict)
222 {
223         QDEBUG("entering for entry %p, verdict %u\n", entry, verdict);
224
225         /* TCP input path (and probably other bits) assume to be called
226          * from softirq context, not from syscall, like issue_verdict is
227          * called.  TCP input path deadlocks with locks taken from timer
228          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
229
230         local_bh_disable();
231         nf_reinject(entry->skb, entry->info, verdict);
232         local_bh_enable();
233
234         kfree(entry);
235 }
236
237 static inline void
238 __enqueue_entry(struct nfqnl_instance *queue,
239                       struct nfqnl_queue_entry *entry)
240 {
241        list_add(&entry->list, &queue->queue_list);
242        queue->queue_total++;
243 }
244
245 /*
246  * Find and return a queued entry matched by cmpfn, or return the last
247  * entry if cmpfn is NULL.
248  */
249 static inline struct nfqnl_queue_entry *
250 __find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, 
251                    unsigned long data)
252 {
253         struct list_head *p;
254
255         list_for_each_prev(p, &queue->queue_list) {
256                 struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p;
257                 
258                 if (!cmpfn || cmpfn(entry, data))
259                         return entry;
260         }
261         return NULL;
262 }
263
264 static inline void
265 __dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry)
266 {
267         list_del(&entry->list);
268         q->queue_total--;
269 }
270
271 static inline struct nfqnl_queue_entry *
272 __find_dequeue_entry(struct nfqnl_instance *queue,
273                      nfqnl_cmpfn cmpfn, unsigned long data)
274 {
275         struct nfqnl_queue_entry *entry;
276
277         entry = __find_entry(queue, cmpfn, data);
278         if (entry == NULL)
279                 return NULL;
280
281         __dequeue_entry(queue, entry);
282         return entry;
283 }
284
285
286 static inline void
287 __nfqnl_flush(struct nfqnl_instance *queue, int verdict)
288 {
289         struct nfqnl_queue_entry *entry;
290         
291         while ((entry = __find_dequeue_entry(queue, NULL, 0)))
292                 issue_verdict(entry, verdict);
293 }
294
295 static inline int
296 __nfqnl_set_mode(struct nfqnl_instance *queue,
297                  unsigned char mode, unsigned int range)
298 {
299         int status = 0;
300         
301         switch (mode) {
302         case NFQNL_COPY_NONE:
303         case NFQNL_COPY_META:
304                 queue->copy_mode = mode;
305                 queue->copy_range = 0;
306                 break;
307                 
308         case NFQNL_COPY_PACKET:
309                 queue->copy_mode = mode;
310                 /* we're using struct nfattr which has 16bit nfa_len */
311                 if (range > 0xffff)
312                         queue->copy_range = 0xffff;
313                 else
314                         queue->copy_range = range;
315                 break;
316                 
317         default:
318                 status = -EINVAL;
319
320         }
321         return status;
322 }
323
324 static struct nfqnl_queue_entry *
325 find_dequeue_entry(struct nfqnl_instance *queue,
326                          nfqnl_cmpfn cmpfn, unsigned long data)
327 {
328         struct nfqnl_queue_entry *entry;
329         
330         spin_lock_bh(&queue->lock);
331         entry = __find_dequeue_entry(queue, cmpfn, data);
332         spin_unlock_bh(&queue->lock);
333
334         return entry;
335 }
336
337 static void
338 nfqnl_flush(struct nfqnl_instance *queue, int verdict)
339 {
340         spin_lock_bh(&queue->lock);
341         __nfqnl_flush(queue, verdict);
342         spin_unlock_bh(&queue->lock);
343 }
344
345 static struct sk_buff *
346 nfqnl_build_packet_message(struct nfqnl_instance *queue,
347                            struct nfqnl_queue_entry *entry, int *errp)
348 {
349         unsigned char *old_tail;
350         size_t size;
351         size_t data_len = 0;
352         struct sk_buff *skb;
353         struct nfqnl_msg_packet_hdr pmsg;
354         struct nlmsghdr *nlh;
355         struct nfgenmsg *nfmsg;
356         unsigned int tmp_uint;
357
358         QDEBUG("entered\n");
359
360         /* all macros expand to constant values at compile time */
361         size =    NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr))
362                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
363                 + NLMSG_SPACE(sizeof(u_int32_t))        /* ifindex */
364                 + NLMSG_SPACE(sizeof(u_int32_t))        /* mark */
365                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw))
366                 + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp));
367
368         spin_lock_bh(&queue->lock);
369         
370         switch (queue->copy_mode) {
371         case NFQNL_COPY_META:
372         case NFQNL_COPY_NONE:
373                 data_len = 0;
374                 break;
375         
376         case NFQNL_COPY_PACKET:
377                 if (queue->copy_range == 0 
378                     || queue->copy_range > entry->skb->len)
379                         data_len = entry->skb->len;
380                 else
381                         data_len = queue->copy_range;
382                 
383                 size += NLMSG_SPACE(data_len);
384                 break;
385         
386         default:
387                 *errp = -EINVAL;
388                 spin_unlock_bh(&queue->lock);
389                 return NULL;
390         }
391
392         spin_unlock_bh(&queue->lock);
393
394         skb = alloc_skb(size, GFP_ATOMIC);
395         if (!skb)
396                 goto nlmsg_failure;
397                 
398         old_tail= skb->tail;
399         nlh = NLMSG_PUT(skb, 0, 0, 
400                         NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
401                         sizeof(struct nfgenmsg));
402         nfmsg = NLMSG_DATA(nlh);
403         nfmsg->nfgen_family = entry->info->pf;
404         nfmsg->version = NFNETLINK_V0;
405         nfmsg->res_id = htons(queue->queue_num);
406
407         pmsg.packet_id          = htonl(entry->id);
408         pmsg.hw_protocol        = htons(entry->skb->protocol);
409         pmsg.hook               = entry->info->hook;
410
411         NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg);
412
413         if (entry->info->indev) {
414                 tmp_uint = htonl(entry->info->indev->ifindex);
415                 NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint);
416         }
417
418         if (entry->info->outdev) {
419                 tmp_uint = htonl(entry->info->outdev->ifindex);
420                 NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint);
421         }
422
423         if (entry->skb->nfmark) {
424                 tmp_uint = htonl(entry->skb->nfmark);
425                 NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
426         }
427
428         if (entry->info->indev && entry->skb->dev
429             && entry->skb->dev->hard_header_parse) {
430                 struct nfqnl_msg_packet_hw phw;
431
432                 phw.hw_addrlen =
433                         entry->skb->dev->hard_header_parse(entry->skb,
434                                                            phw.hw_addr);
435                 phw.hw_addrlen = htons(phw.hw_addrlen);
436                 NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
437         }
438
439         if (entry->skb->stamp.tv_sec) {
440                 struct nfqnl_msg_packet_timestamp ts;
441
442                 ts.sec = htonll(entry->skb->stamp.tv_sec);
443                 ts.usec = htonll(entry->skb->stamp.tv_usec);
444
445                 NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
446         }
447
448         if (data_len) {
449                 struct nfattr *nfa;
450                 int size = NFA_LENGTH(data_len);
451
452                 if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) {
453                         printk(KERN_WARNING "nf_queue: no tailroom!\n");
454                         goto nlmsg_failure;
455                 }
456
457                 nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
458                 nfa->nfa_type = NFQA_PAYLOAD;
459                 nfa->nfa_len = size;
460
461                 if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len))
462                         BUG();
463         }
464                 
465         nlh->nlmsg_len = skb->tail - old_tail;
466         return skb;
467
468 nlmsg_failure:
469 nfattr_failure:
470         if (skb)
471                 kfree_skb(skb);
472         *errp = -EINVAL;
473         if (net_ratelimit())
474                 printk(KERN_ERR "nf_queue: error creating packet message\n");
475         return NULL;
476 }
477
478 static int
479 nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info, 
480                      unsigned int queuenum, void *data)
481 {
482         int status = -EINVAL;
483         struct sk_buff *nskb;
484         struct nfqnl_instance *queue;
485         struct nfqnl_queue_entry *entry;
486
487         QDEBUG("entered\n");
488
489         queue = instance_lookup_get(queuenum);
490         if (!queue) {
491                 QDEBUG("no queue instance matching\n");
492                 return -EINVAL;
493         }
494
495         if (queue->copy_mode == NFQNL_COPY_NONE) {
496                 QDEBUG("mode COPY_NONE, aborting\n");
497                 status = -EAGAIN;
498                 goto err_out_put;
499         }
500
501         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
502         if (entry == NULL) {
503                 if (net_ratelimit())
504                         printk(KERN_ERR 
505                                 "nf_queue: OOM in nfqnl_enqueue_packet()\n");
506                 status = -ENOMEM;
507                 goto err_out_put;
508         }
509
510         entry->info = info;
511         entry->skb = skb;
512         entry->id = atomic_inc_return(&queue->id_sequence);
513
514         nskb = nfqnl_build_packet_message(queue, entry, &status);
515         if (nskb == NULL)
516                 goto err_out_free;
517                 
518         spin_lock_bh(&queue->lock);
519         
520         if (!queue->peer_pid)
521                 goto err_out_free_nskb; 
522
523         if (queue->queue_total >= queue->queue_maxlen) {
524                 queue->queue_dropped++;
525                 status = -ENOSPC;
526                 if (net_ratelimit())
527                           printk(KERN_WARNING "ip_queue: full at %d entries, "
528                                  "dropping packets(s). Dropped: %d\n", 
529                                  queue->queue_total, queue->queue_dropped);
530                 goto err_out_free_nskb;
531         }
532
533         /* nfnetlink_unicast will either free the nskb or add it to a socket */
534         status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
535         if (status < 0) {
536                 queue->queue_user_dropped++;
537                 goto err_out_unlock;
538         }
539
540         __enqueue_entry(queue, entry);
541
542         spin_unlock_bh(&queue->lock);
543         instance_put(queue);
544         return status;
545
546 err_out_free_nskb:
547         kfree_skb(nskb); 
548         
549 err_out_unlock:
550         spin_unlock_bh(&queue->lock);
551
552 err_out_free:
553         kfree(entry);
554 err_out_put:
555         instance_put(queue);
556         return status;
557 }
558
559 static int
560 nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
561 {
562         int diff;
563
564         diff = data_len - e->skb->len;
565         if (diff < 0)
566                 skb_trim(e->skb, data_len);
567         else if (diff > 0) {
568                 if (data_len > 0xFFFF)
569                         return -EINVAL;
570                 if (diff > skb_tailroom(e->skb)) {
571                         struct sk_buff *newskb;
572                         
573                         newskb = skb_copy_expand(e->skb,
574                                                  skb_headroom(e->skb),
575                                                  diff,
576                                                  GFP_ATOMIC);
577                         if (newskb == NULL) {
578                                 printk(KERN_WARNING "ip_queue: OOM "
579                                       "in mangle, dropping packet\n");
580                                 return -ENOMEM;
581                         }
582                         if (e->skb->sk)
583                                 skb_set_owner_w(newskb, e->skb->sk);
584                         kfree_skb(e->skb);
585                         e->skb = newskb;
586                 }
587                 skb_put(e->skb, diff);
588         }
589         if (!skb_make_writable(&e->skb, data_len))
590                 return -ENOMEM;
591         memcpy(e->skb->data, data, data_len);
592
593         return 0;
594 }
595
596 static inline int
597 id_cmp(struct nfqnl_queue_entry *e, unsigned long id)
598 {
599         return (id == e->id);
600 }
601
602 static int
603 nfqnl_set_mode(struct nfqnl_instance *queue,
604                unsigned char mode, unsigned int range)
605 {
606         int status;
607
608         spin_lock_bh(&queue->lock);
609         status = __nfqnl_set_mode(queue, mode, range);
610         spin_unlock_bh(&queue->lock);
611
612         return status;
613 }
614
615 static int
616 dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex)
617 {
618         if (entry->info->indev)
619                 if (entry->info->indev->ifindex == ifindex)
620                         return 1;
621                         
622         if (entry->info->outdev)
623                 if (entry->info->outdev->ifindex == ifindex)
624                         return 1;
625
626         return 0;
627 }
628
629 /* drop all packets with either indev or outdev == ifindex from all queue
630  * instances */
631 static void
632 nfqnl_dev_drop(int ifindex)
633 {
634         int i;
635         
636         QDEBUG("entering for ifindex %u\n", ifindex);
637
638         /* this only looks like we have to hold the readlock for a way too long
639          * time, issue_verdict(),  nf_reinject(), ... - but we always only
640          * issue NF_DROP, which is processed directly in nf_reinject() */
641         read_lock_bh(&instances_lock);
642
643         for  (i = 0; i < INSTANCE_BUCKETS; i++) {
644                 struct hlist_node *tmp;
645                 struct nfqnl_instance *inst;
646                 struct hlist_head *head = &instance_table[i];
647
648                 hlist_for_each_entry(inst, tmp, head, hlist) {
649                         struct nfqnl_queue_entry *entry;
650                         while ((entry = find_dequeue_entry(inst, dev_cmp, 
651                                                            ifindex)) != NULL)
652                                 issue_verdict(entry, NF_DROP);
653                 }
654         }
655
656         read_unlock_bh(&instances_lock);
657 }
658
659 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
660
661 static int
662 nfqnl_rcv_dev_event(struct notifier_block *this,
663                     unsigned long event, void *ptr)
664 {
665         struct net_device *dev = ptr;
666
667         /* Drop any packets associated with the downed device */
668         if (event == NETDEV_DOWN)
669                 nfqnl_dev_drop(dev->ifindex);
670         return NOTIFY_DONE;
671 }
672
673 static struct notifier_block nfqnl_dev_notifier = {
674         .notifier_call  = nfqnl_rcv_dev_event,
675 };
676
677 static int
678 nfqnl_rcv_nl_event(struct notifier_block *this,
679                    unsigned long event, void *ptr)
680 {
681         struct netlink_notify *n = ptr;
682
683         if (event == NETLINK_URELEASE &&
684             n->protocol == NETLINK_NETFILTER && n->pid) {
685                 int i;
686
687                 /* destroy all instances for this pid */
688                 write_lock_bh(&instances_lock);
689                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
690                         struct hlist_node *tmp, *t2;
691                         struct nfqnl_instance *inst;
692                         struct hlist_head *head = &instance_table[i];
693
694                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
695                                 if (n->pid == inst->peer_pid)
696                                         __instance_destroy(inst);
697                         }
698                 }
699                 write_unlock_bh(&instances_lock);
700         }
701         return NOTIFY_DONE;
702 }
703
704 static struct notifier_block nfqnl_rtnl_notifier = {
705         .notifier_call  = nfqnl_rcv_nl_event,
706 };
707
708 static const int nfqa_verdict_min[NFQA_MAX] = {
709         [NFQA_VERDICT_HDR-1]    = sizeof(struct nfqnl_msg_verdict_hdr),
710         [NFQA_MARK-1]           = sizeof(u_int32_t),
711         [NFQA_PAYLOAD-1]        = 0,
712 };
713
714 static int
715 nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
716                    struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
717 {
718         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
719         u_int16_t queue_num = ntohs(nfmsg->res_id);
720
721         struct nfqnl_msg_verdict_hdr *vhdr;
722         struct nfqnl_instance *queue;
723         unsigned int verdict;
724         struct nfqnl_queue_entry *entry;
725         int err;
726
727         if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) {
728                 QDEBUG("bad attribute size\n");
729                 return -EINVAL;
730         }
731
732         queue = instance_lookup_get(queue_num);
733         if (!queue)
734                 return -ENODEV;
735
736         if (queue->peer_pid != NETLINK_CB(skb).pid) {
737                 err = -EPERM;
738                 goto err_out_put;
739         }
740
741         if (!nfqa[NFQA_VERDICT_HDR-1]) {
742                 err = -EINVAL;
743                 goto err_out_put;
744         }
745
746         vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]);
747         verdict = ntohl(vhdr->verdict);
748
749         if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
750                 err = -EINVAL;
751                 goto err_out_put;
752         }
753
754         entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
755         if (entry == NULL) {
756                 err = -ENOENT;
757                 goto err_out_put;
758         }
759
760         if (nfqa[NFQA_PAYLOAD-1]) {
761                 if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]),
762                                  NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0)
763                         verdict = NF_DROP;
764         }
765
766         if (nfqa[NFQA_MARK-1])
767                 skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1]));
768                 
769         issue_verdict(entry, verdict);
770         instance_put(queue);
771         return 0;
772
773 err_out_put:
774         instance_put(queue);
775         return err;
776 }
777
778 static int
779 nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
780                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
781 {
782         return -ENOTSUPP;
783 }
784
785 static const int nfqa_cfg_min[NFQA_CFG_MAX] = {
786         [NFQA_CFG_CMD-1]        = sizeof(struct nfqnl_msg_config_cmd),
787         [NFQA_CFG_PARAMS-1]     = sizeof(struct nfqnl_msg_config_params),
788 };
789
790 static int
791 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
792                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
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         if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) {
802                 QDEBUG("bad attribute size\n");
803                 return -EINVAL;
804         }
805
806         queue = instance_lookup_get(queue_num);
807         if (nfqa[NFQA_CFG_CMD-1]) {
808                 struct nfqnl_msg_config_cmd *cmd;
809                 cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]);
810                 QDEBUG("found CFG_CMD\n");
811
812                 switch (cmd->command) {
813                 case NFQNL_CFG_CMD_BIND:
814                         if (queue)
815                                 return -EBUSY;
816
817                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
818                         if (!queue)
819                                 return -EINVAL;
820                         break;
821                 case NFQNL_CFG_CMD_UNBIND:
822                         if (!queue)
823                                 return -ENODEV;
824
825                         if (queue->peer_pid != NETLINK_CB(skb).pid) {
826                                 ret = -EPERM;
827                                 goto out_put;
828                         }
829
830                         instance_destroy(queue);
831                         break;
832                 case NFQNL_CFG_CMD_PF_BIND:
833                         QDEBUG("registering queue handler for pf=%u\n",
834                                 ntohs(cmd->pf));
835                         ret = nf_register_queue_handler(ntohs(cmd->pf),
836                                                         nfqnl_enqueue_packet,
837                                                         NULL);
838
839                         break;
840                 case NFQNL_CFG_CMD_PF_UNBIND:
841                         QDEBUG("unregistering queue handler for pf=%u\n",
842                                 ntohs(cmd->pf));
843                         /* This is a bug and a feature.  We can unregister
844                          * other handlers(!) */
845                         ret = nf_unregister_queue_handler(ntohs(cmd->pf));
846                         break;
847                 default:
848                         ret = -EINVAL;
849                         break;
850                 }
851         } else {
852                 if (!queue) {
853                         QDEBUG("no config command, and no instance ENOENT\n");
854                         ret = -ENOENT;
855                         goto out_put;
856                 }
857
858                 if (queue->peer_pid != NETLINK_CB(skb).pid) {
859                         QDEBUG("no config command, and wrong pid\n");
860                         ret = -EPERM;
861                         goto out_put;
862                 }
863         }
864
865         if (nfqa[NFQA_CFG_PARAMS-1]) {
866                 struct nfqnl_msg_config_params *params;
867                 params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]);
868
869                 nfqnl_set_mode(queue, params->copy_mode,
870                                 ntohl(params->copy_range));
871         }
872
873 out_put:
874         instance_put(queue);
875         return ret;
876 }
877
878 static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
879         [NFQNL_MSG_PACKET]      = { .call = nfqnl_recv_unsupp,
880                                     .attr_count = NFQA_MAX,
881                                     .cap_required = CAP_NET_ADMIN },
882         [NFQNL_MSG_VERDICT]     = { .call = nfqnl_recv_verdict,
883                                     .attr_count = NFQA_MAX,
884                                     .cap_required = CAP_NET_ADMIN },
885         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
886                                     .attr_count = NFQA_CFG_MAX,
887                                     .cap_required = CAP_NET_ADMIN },
888 };
889
890 static struct nfnetlink_subsystem nfqnl_subsys = {
891         .name           = "nf_queue",
892         .subsys_id      = NFNL_SUBSYS_QUEUE,
893         .cb_count       = NFQNL_MSG_MAX,
894         .cb             = nfqnl_cb,
895 };
896
897 #ifdef CONFIG_PROC_FS
898 struct iter_state {
899         unsigned int bucket;
900 };
901
902 static struct hlist_node *get_first(struct seq_file *seq)
903 {
904         struct iter_state *st = seq->private;
905
906         if (!st)
907                 return NULL;
908
909         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
910                 if (!hlist_empty(&instance_table[st->bucket]))
911                         return instance_table[st->bucket].first;
912         }
913         return NULL;
914 }
915
916 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
917 {
918         struct iter_state *st = seq->private;
919
920         h = h->next;
921         while (!h) {
922                 if (++st->bucket >= INSTANCE_BUCKETS)
923                         return NULL;
924
925                 h = instance_table[st->bucket].first;
926         }
927         return h;
928 }
929
930 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
931 {
932         struct hlist_node *head;
933         head = get_first(seq);
934
935         if (head)
936                 while (pos && (head = get_next(seq, head)))
937                         pos--;
938         return pos ? NULL : head;
939 }
940
941 static void *seq_start(struct seq_file *seq, loff_t *pos)
942 {
943         read_lock_bh(&instances_lock);
944         return get_idx(seq, *pos);
945 }
946
947 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
948 {
949         (*pos)++;
950         return get_next(s, v);
951 }
952
953 static void seq_stop(struct seq_file *s, void *v)
954 {
955         read_unlock_bh(&instances_lock);
956 }
957
958 static int seq_show(struct seq_file *s, void *v)
959 {
960         const struct nfqnl_instance *inst = v;
961
962         return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
963                           inst->queue_num,
964                           inst->peer_pid, inst->queue_total,
965                           inst->copy_mode, inst->copy_range,
966                           inst->queue_dropped, inst->queue_user_dropped,
967                           atomic_read(&inst->id_sequence),
968                           atomic_read(&inst->use));
969 }
970
971 static struct seq_operations nfqnl_seq_ops = {
972         .start  = seq_start,
973         .next   = seq_next,
974         .stop   = seq_stop,
975         .show   = seq_show,
976 };
977
978 static int nfqnl_open(struct inode *inode, struct file *file)
979 {
980         struct seq_file *seq;
981         struct iter_state *is;
982         int ret;
983
984         is = kmalloc(sizeof(*is), GFP_KERNEL);
985         if (!is)
986                 return -ENOMEM;
987         memset(is, 0, sizeof(*is));
988         ret = seq_open(file, &nfqnl_seq_ops);
989         if (ret < 0)
990                 goto out_free;
991         seq = file->private_data;
992         seq->private = is;
993         return ret;
994 out_free:
995         kfree(is);
996         return ret;
997 }
998
999 static struct file_operations nfqnl_file_ops = {
1000         .owner   = THIS_MODULE,
1001         .open    = nfqnl_open,
1002         .read    = seq_read,
1003         .llseek  = seq_lseek,
1004         .release = seq_release_private,
1005 };
1006
1007 #endif /* PROC_FS */
1008
1009 static int
1010 init_or_cleanup(int init)
1011 {
1012         int i, status = -ENOMEM;
1013 #ifdef CONFIG_PROC_FS
1014         struct proc_dir_entry *proc_nfqueue;
1015 #endif
1016         
1017         if (!init)
1018                 goto cleanup;
1019
1020         for (i = 0; i < INSTANCE_BUCKETS; i++)
1021                 INIT_HLIST_HEAD(&instance_table[i]);
1022
1023         netlink_register_notifier(&nfqnl_rtnl_notifier);
1024         status = nfnetlink_subsys_register(&nfqnl_subsys);
1025         if (status < 0) {
1026                 printk(KERN_ERR "nf_queue: failed to create netlink socket\n");
1027                 goto cleanup_netlink_notifier;
1028         }
1029
1030 #ifdef CONFIG_PROC_FS
1031         proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
1032                                          proc_net_netfilter);
1033         if (!proc_nfqueue)
1034                 goto cleanup_subsys;
1035         proc_nfqueue->proc_fops = &nfqnl_file_ops;
1036 #endif
1037
1038         register_netdevice_notifier(&nfqnl_dev_notifier);
1039
1040         return status;
1041
1042 cleanup:
1043         nf_unregister_queue_handlers(nfqnl_enqueue_packet);
1044         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1045 #ifdef CONFIG_PROC_FS
1046         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
1047 cleanup_subsys:
1048 #endif  
1049         nfnetlink_subsys_unregister(&nfqnl_subsys);
1050 cleanup_netlink_notifier:
1051         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1052         return status;
1053 }
1054
1055 static int __init init(void)
1056 {
1057         
1058         return init_or_cleanup(1);
1059 }
1060
1061 static void __exit fini(void)
1062 {
1063         init_or_cleanup(0);
1064 }
1065
1066 MODULE_DESCRIPTION("netfilter packet queue handler");
1067 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1068 MODULE_LICENSE("GPL");
1069 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1070
1071 module_init(init);
1072 module_exit(fini);