[NET]: Make all initialized struct seq_operations const.
[linux-2.6.git] / net / netfilter / nfnetlink_log.c
1 /*
2  * This is a module which is used for logging packets to userspace via
3  * nfetlink.
4  *
5  * (C) 2005 by Harald Welte <laforge@netfilter.org>
6  *
7  * Based on the old ipv4-only ipt_ULOG.c:
8  * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/init.h>
17 #include <linux/ip.h>
18 #include <linux/ipv6.h>
19 #include <linux/netdevice.h>
20 #include <linux/netfilter.h>
21 #include <linux/netlink.h>
22 #include <linux/netfilter/nfnetlink.h>
23 #include <linux/netfilter/nfnetlink_log.h>
24 #include <linux/spinlock.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/list.h>
29 #include <linux/jhash.h>
30 #include <linux/random.h>
31 #include <net/sock.h>
32
33 #include <asm/atomic.h>
34
35 #ifdef CONFIG_BRIDGE_NETFILTER
36 #include "../bridge/br_private.h"
37 #endif
38
39 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
40 #define NFULNL_TIMEOUT_DEFAULT  100     /* every second */
41 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
42
43 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
44                                      printk(x, ## args); } while (0);
45
46 #if 0
47 #define UDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
48                                         __FILE__, __LINE__, __FUNCTION__,  \
49                                         ## args)
50 #else
51 #define UDEBUG(x, ...)
52 #endif
53
54 struct nfulnl_instance {
55         struct hlist_node hlist;        /* global list of instances */
56         spinlock_t lock;
57         atomic_t use;                   /* use count */
58
59         unsigned int qlen;              /* number of nlmsgs in skb */
60         struct sk_buff *skb;            /* pre-allocatd skb */
61         struct nlmsghdr *lastnlh;       /* netlink header of last msg in skb */
62         struct timer_list timer;
63         int peer_pid;                   /* PID of the peer process */
64
65         /* configurable parameters */
66         unsigned int flushtimeout;      /* timeout until queue flush */
67         unsigned int nlbufsiz;          /* netlink buffer allocation size */
68         unsigned int qthreshold;        /* threshold of the queue */
69         u_int32_t copy_range;
70         u_int32_t seq;                  /* instance-local sequential counter */
71         u_int16_t group_num;            /* number of this queue */
72         u_int16_t flags;
73         u_int8_t copy_mode;
74 };
75
76 static DEFINE_RWLOCK(instances_lock);
77 static atomic_t global_seq;
78
79 #define INSTANCE_BUCKETS        16
80 static struct hlist_head instance_table[INSTANCE_BUCKETS];
81 static unsigned int hash_init;
82
83 static inline u_int8_t instance_hashfn(u_int16_t group_num)
84 {
85         return ((group_num & 0xff) % INSTANCE_BUCKETS);
86 }
87
88 static struct nfulnl_instance *
89 __instance_lookup(u_int16_t group_num)
90 {
91         struct hlist_head *head;
92         struct hlist_node *pos;
93         struct nfulnl_instance *inst;
94
95         UDEBUG("entering (group_num=%u)\n", group_num);
96
97         head = &instance_table[instance_hashfn(group_num)];
98         hlist_for_each_entry(inst, pos, head, hlist) {
99                 if (inst->group_num == group_num)
100                         return inst;
101         }
102         return NULL;
103 }
104
105 static inline void
106 instance_get(struct nfulnl_instance *inst)
107 {
108         atomic_inc(&inst->use);
109 }
110
111 static struct nfulnl_instance *
112 instance_lookup_get(u_int16_t group_num)
113 {
114         struct nfulnl_instance *inst;
115
116         read_lock_bh(&instances_lock);
117         inst = __instance_lookup(group_num);
118         if (inst)
119                 instance_get(inst);
120         read_unlock_bh(&instances_lock);
121
122         return inst;
123 }
124
125 static void
126 instance_put(struct nfulnl_instance *inst)
127 {
128         if (inst && atomic_dec_and_test(&inst->use)) {
129                 UDEBUG("kfree(inst=%p)\n", inst);
130                 kfree(inst);
131                 module_put(THIS_MODULE);
132         }
133 }
134
135 static void nfulnl_timer(unsigned long data);
136
137 static struct nfulnl_instance *
138 instance_create(u_int16_t group_num, int pid)
139 {
140         struct nfulnl_instance *inst;
141
142         UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
143                 pid);
144
145         write_lock_bh(&instances_lock);
146         if (__instance_lookup(group_num)) {
147                 inst = NULL;
148                 UDEBUG("aborting, instance already exists\n");
149                 goto out_unlock;
150         }
151
152         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
153         if (!inst)
154                 goto out_unlock;
155
156         INIT_HLIST_NODE(&inst->hlist);
157         spin_lock_init(&inst->lock);
158         /* needs to be two, since we _put() after creation */
159         atomic_set(&inst->use, 2);
160
161         setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
162
163         inst->peer_pid = pid;
164         inst->group_num = group_num;
165
166         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
167         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
168         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
169         inst->copy_mode         = NFULNL_COPY_PACKET;
170         inst->copy_range        = 0xffff;
171
172         if (!try_module_get(THIS_MODULE))
173                 goto out_free;
174
175         hlist_add_head(&inst->hlist,
176                        &instance_table[instance_hashfn(group_num)]);
177
178         UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
179                 inst->hlist.next);
180
181         write_unlock_bh(&instances_lock);
182
183         return inst;
184
185 out_free:
186         instance_put(inst);
187 out_unlock:
188         write_unlock_bh(&instances_lock);
189         return NULL;
190 }
191
192 static int __nfulnl_send(struct nfulnl_instance *inst);
193
194 static void
195 __instance_destroy(struct nfulnl_instance *inst)
196 {
197         /* first pull it out of the global list */
198         UDEBUG("removing instance %p (queuenum=%u) from hash\n",
199                 inst, inst->group_num);
200
201         hlist_del(&inst->hlist);
202
203         /* then flush all pending packets from skb */
204
205         spin_lock_bh(&inst->lock);
206         if (inst->skb) {
207                 /* timer "holds" one reference (we have one more) */
208                 if (del_timer(&inst->timer))
209                         instance_put(inst);
210                 if (inst->qlen)
211                         __nfulnl_send(inst);
212                 if (inst->skb) {
213                         kfree_skb(inst->skb);
214                         inst->skb = NULL;
215                 }
216         }
217         spin_unlock_bh(&inst->lock);
218
219         /* and finally put the refcount */
220         instance_put(inst);
221 }
222
223 static inline void
224 instance_destroy(struct nfulnl_instance *inst)
225 {
226         write_lock_bh(&instances_lock);
227         __instance_destroy(inst);
228         write_unlock_bh(&instances_lock);
229 }
230
231 static int
232 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
233                   unsigned int range)
234 {
235         int status = 0;
236
237         spin_lock_bh(&inst->lock);
238
239         switch (mode) {
240         case NFULNL_COPY_NONE:
241         case NFULNL_COPY_META:
242                 inst->copy_mode = mode;
243                 inst->copy_range = 0;
244                 break;
245
246         case NFULNL_COPY_PACKET:
247                 inst->copy_mode = mode;
248                 /* we're using struct nfattr which has 16bit nfa_len */
249                 if (range > 0xffff)
250                         inst->copy_range = 0xffff;
251                 else
252                         inst->copy_range = range;
253                 break;
254
255         default:
256                 status = -EINVAL;
257                 break;
258         }
259
260         spin_unlock_bh(&inst->lock);
261
262         return status;
263 }
264
265 static int
266 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
267 {
268         int status;
269
270         spin_lock_bh(&inst->lock);
271         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
272                 status = -ERANGE;
273         else if (nlbufsiz > 131072)
274                 status = -ERANGE;
275         else {
276                 inst->nlbufsiz = nlbufsiz;
277                 status = 0;
278         }
279         spin_unlock_bh(&inst->lock);
280
281         return status;
282 }
283
284 static int
285 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
286 {
287         spin_lock_bh(&inst->lock);
288         inst->flushtimeout = timeout;
289         spin_unlock_bh(&inst->lock);
290
291         return 0;
292 }
293
294 static int
295 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
296 {
297         spin_lock_bh(&inst->lock);
298         inst->qthreshold = qthresh;
299         spin_unlock_bh(&inst->lock);
300
301         return 0;
302 }
303
304 static int
305 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
306 {
307         spin_lock_bh(&inst->lock);
308         inst->flags = flags;
309         spin_unlock_bh(&inst->lock);
310
311         return 0;
312 }
313
314 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
315                                         unsigned int pkt_size)
316 {
317         struct sk_buff *skb;
318         unsigned int n;
319
320         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
321
322         /* alloc skb which should be big enough for a whole multipart
323          * message.  WARNING: has to be <= 128k due to slab restrictions */
324
325         n = max(inst_size, pkt_size);
326         skb = alloc_skb(n, GFP_ATOMIC);
327         if (!skb) {
328                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
329                         inst_size);
330
331                 if (n > pkt_size) {
332                         /* try to allocate only as much as we need for current
333                          * packet */
334
335                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
336                         if (!skb)
337                                 PRINTR("nfnetlink_log: can't even alloc %u "
338                                        "bytes\n", pkt_size);
339                 }
340         }
341
342         return skb;
343 }
344
345 static int
346 __nfulnl_send(struct nfulnl_instance *inst)
347 {
348         int status;
349
350         if (inst->qlen > 1)
351                 inst->lastnlh->nlmsg_type = NLMSG_DONE;
352
353         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
354         if (status < 0) {
355                 UDEBUG("netlink_unicast() failed\n");
356                 /* FIXME: statistics */
357         }
358
359         inst->qlen = 0;
360         inst->skb = NULL;
361         inst->lastnlh = NULL;
362
363         return status;
364 }
365
366 static void nfulnl_timer(unsigned long data)
367 {
368         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
369
370         UDEBUG("timer function called, flushing buffer\n");
371
372         spin_lock_bh(&inst->lock);
373         if (inst->skb)
374                 __nfulnl_send(inst);
375         spin_unlock_bh(&inst->lock);
376         instance_put(inst);
377 }
378
379 /* This is an inline function, we don't really care about a long
380  * list of arguments */
381 static inline int
382 __build_packet_message(struct nfulnl_instance *inst,
383                         const struct sk_buff *skb,
384                         unsigned int data_len,
385                         unsigned int pf,
386                         unsigned int hooknum,
387                         const struct net_device *indev,
388                         const struct net_device *outdev,
389                         const struct nf_loginfo *li,
390                         const char *prefix, unsigned int plen)
391 {
392         struct nfulnl_msg_packet_hdr pmsg;
393         struct nlmsghdr *nlh;
394         struct nfgenmsg *nfmsg;
395         __be32 tmp_uint;
396         sk_buff_data_t old_tail = inst->skb->tail;
397
398         UDEBUG("entered\n");
399
400         nlh = NLMSG_PUT(inst->skb, 0, 0,
401                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
402                         sizeof(struct nfgenmsg));
403         nfmsg = NLMSG_DATA(nlh);
404         nfmsg->nfgen_family = pf;
405         nfmsg->version = NFNETLINK_V0;
406         nfmsg->res_id = htons(inst->group_num);
407
408         pmsg.hw_protocol        = skb->protocol;
409         pmsg.hook               = hooknum;
410
411         NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
412
413         if (prefix)
414                 NFA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
415
416         if (indev) {
417                 tmp_uint = htonl(indev->ifindex);
418 #ifndef CONFIG_BRIDGE_NETFILTER
419                 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
420                         &tmp_uint);
421 #else
422                 if (pf == PF_BRIDGE) {
423                         /* Case 1: outdev is physical input device, we need to
424                          * look for bridge group (when called from
425                          * netfilter_bridge) */
426                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
427                                 sizeof(tmp_uint), &tmp_uint);
428                         /* this is the bridge group "brX" */
429                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
430                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
431                                 sizeof(tmp_uint), &tmp_uint);
432                 } else {
433                         /* Case 2: indev is bridge group, we need to look for
434                          * physical device (when called from ipv4) */
435                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
436                                 sizeof(tmp_uint), &tmp_uint);
437                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
438                                 tmp_uint =
439                                     htonl(skb->nf_bridge->physindev->ifindex);
440                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
441                                         sizeof(tmp_uint), &tmp_uint);
442                         }
443                 }
444 #endif
445         }
446
447         if (outdev) {
448                 tmp_uint = htonl(outdev->ifindex);
449 #ifndef CONFIG_BRIDGE_NETFILTER
450                 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
451                         &tmp_uint);
452 #else
453                 if (pf == PF_BRIDGE) {
454                         /* Case 1: outdev is physical output device, we need to
455                          * look for bridge group (when called from
456                          * netfilter_bridge) */
457                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
458                                 sizeof(tmp_uint), &tmp_uint);
459                         /* this is the bridge group "brX" */
460                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
461                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
462                                 sizeof(tmp_uint), &tmp_uint);
463                 } else {
464                         /* Case 2: indev is a bridge group, we need to look
465                          * for physical device (when called from ipv4) */
466                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
467                                 sizeof(tmp_uint), &tmp_uint);
468                         if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
469                                 tmp_uint =
470                                     htonl(skb->nf_bridge->physoutdev->ifindex);
471                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
472                                         sizeof(tmp_uint), &tmp_uint);
473                         }
474                 }
475 #endif
476         }
477
478         if (skb->mark) {
479                 tmp_uint = htonl(skb->mark);
480                 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
481         }
482
483         if (indev && skb->dev && skb->dev->hard_header_parse) {
484                 struct nfulnl_msg_packet_hw phw;
485                 int len = skb->dev->hard_header_parse((struct sk_buff *)skb,
486                                                     phw.hw_addr);
487                 phw.hw_addrlen = htons(len);
488                 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
489         }
490
491         if (skb->tstamp.tv64) {
492                 struct nfulnl_msg_packet_timestamp ts;
493                 struct timeval tv = ktime_to_timeval(skb->tstamp);
494                 ts.sec = cpu_to_be64(tv.tv_sec);
495                 ts.usec = cpu_to_be64(tv.tv_usec);
496
497                 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
498         }
499
500         /* UID */
501         if (skb->sk) {
502                 read_lock_bh(&skb->sk->sk_callback_lock);
503                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
504                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
505                         /* need to unlock here since NFA_PUT may goto */
506                         read_unlock_bh(&skb->sk->sk_callback_lock);
507                         NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
508                 } else
509                         read_unlock_bh(&skb->sk->sk_callback_lock);
510         }
511
512         /* local sequence number */
513         if (inst->flags & NFULNL_CFG_F_SEQ) {
514                 tmp_uint = htonl(inst->seq++);
515                 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
516         }
517         /* global sequence number */
518         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
519                 tmp_uint = htonl(atomic_inc_return(&global_seq));
520                 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
521         }
522
523         if (data_len) {
524                 struct nfattr *nfa;
525                 int size = NFA_LENGTH(data_len);
526
527                 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
528                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
529                         goto nlmsg_failure;
530                 }
531
532                 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
533                 nfa->nfa_type = NFULA_PAYLOAD;
534                 nfa->nfa_len = size;
535
536                 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
537                         BUG();
538         }
539
540         nlh->nlmsg_len = inst->skb->tail - old_tail;
541         inst->lastnlh = nlh;
542         return 0;
543
544 nlmsg_failure:
545         UDEBUG("nlmsg_failure\n");
546 nfattr_failure:
547         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
548         return -1;
549 }
550
551 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
552
553 static struct nf_loginfo default_loginfo = {
554         .type =         NF_LOG_TYPE_ULOG,
555         .u = {
556                 .ulog = {
557                         .copy_len       = 0xffff,
558                         .group          = 0,
559                         .qthreshold     = 1,
560                 },
561         },
562 };
563
564 /* log handler for internal netfilter logging api */
565 static void
566 nfulnl_log_packet(unsigned int pf,
567                   unsigned int hooknum,
568                   const struct sk_buff *skb,
569                   const struct net_device *in,
570                   const struct net_device *out,
571                   const struct nf_loginfo *li_user,
572                   const char *prefix)
573 {
574         unsigned int size, data_len;
575         struct nfulnl_instance *inst;
576         const struct nf_loginfo *li;
577         unsigned int qthreshold;
578         unsigned int plen;
579
580         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
581                 li = li_user;
582         else
583                 li = &default_loginfo;
584
585         inst = instance_lookup_get(li->u.ulog.group);
586         if (!inst)
587                 return;
588
589         plen = 0;
590         if (prefix)
591                 plen = strlen(prefix) + 1;
592
593         /* all macros expand to constant values at compile time */
594         /* FIXME: do we want to make the size calculation conditional based on
595          * what is actually present?  way more branches and checks, but more
596          * memory efficient... */
597         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
598                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
599                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
600                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
601 #ifdef CONFIG_BRIDGE_NETFILTER
602                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
603                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
604 #endif
605                 + NFA_SPACE(sizeof(u_int32_t))  /* mark */
606                 + NFA_SPACE(sizeof(u_int32_t))  /* uid */
607                 + NFA_SPACE(plen)               /* prefix */
608                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
609                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
610
611         UDEBUG("initial size=%u\n", size);
612
613         spin_lock_bh(&inst->lock);
614
615         if (inst->flags & NFULNL_CFG_F_SEQ)
616                 size += NFA_SPACE(sizeof(u_int32_t));
617         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
618                 size += NFA_SPACE(sizeof(u_int32_t));
619
620         qthreshold = inst->qthreshold;
621         /* per-rule qthreshold overrides per-instance */
622         if (qthreshold > li->u.ulog.qthreshold)
623                 qthreshold = li->u.ulog.qthreshold;
624
625         switch (inst->copy_mode) {
626         case NFULNL_COPY_META:
627         case NFULNL_COPY_NONE:
628                 data_len = 0;
629                 break;
630
631         case NFULNL_COPY_PACKET:
632                 if (inst->copy_range == 0
633                     || inst->copy_range > skb->len)
634                         data_len = skb->len;
635                 else
636                         data_len = inst->copy_range;
637
638                 size += NFA_SPACE(data_len);
639                 UDEBUG("copy_packet, therefore size now %u\n", size);
640                 break;
641
642         default:
643                 goto unlock_and_release;
644         }
645
646         if (inst->qlen >= qthreshold ||
647             (inst->skb && size > skb_tailroom(inst->skb))) {
648                 /* either the queue len is too high or we don't have
649                  * enough room in the skb left. flush to userspace. */
650                 UDEBUG("flushing old skb\n");
651
652                 /* timer "holds" one reference (we have another one) */
653                 if (del_timer(&inst->timer))
654                         instance_put(inst);
655                 __nfulnl_send(inst);
656         }
657
658         if (!inst->skb) {
659                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
660                 if (!inst->skb)
661                         goto alloc_failure;
662         }
663
664         UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
665         inst->qlen++;
666
667         __build_packet_message(inst, skb, data_len, pf,
668                                 hooknum, in, out, li, prefix, plen);
669
670         /* timer_pending always called within inst->lock, so there
671          * is no chance of a race here */
672         if (!timer_pending(&inst->timer)) {
673                 instance_get(inst);
674                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
675                 add_timer(&inst->timer);
676         }
677
678 unlock_and_release:
679         spin_unlock_bh(&inst->lock);
680         instance_put(inst);
681         return;
682
683 alloc_failure:
684         UDEBUG("error allocating skb\n");
685         /* FIXME: statistics */
686         goto unlock_and_release;
687 }
688
689 static int
690 nfulnl_rcv_nl_event(struct notifier_block *this,
691                    unsigned long event, void *ptr)
692 {
693         struct netlink_notify *n = ptr;
694
695         if (event == NETLINK_URELEASE &&
696             n->protocol == NETLINK_NETFILTER && n->pid) {
697                 int i;
698
699                 /* destroy all instances for this pid */
700                 write_lock_bh(&instances_lock);
701                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
702                         struct hlist_node *tmp, *t2;
703                         struct nfulnl_instance *inst;
704                         struct hlist_head *head = &instance_table[i];
705
706                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
707                                 UDEBUG("node = %p\n", inst);
708                                 if (n->pid == inst->peer_pid)
709                                         __instance_destroy(inst);
710                         }
711                 }
712                 write_unlock_bh(&instances_lock);
713         }
714         return NOTIFY_DONE;
715 }
716
717 static struct notifier_block nfulnl_rtnl_notifier = {
718         .notifier_call  = nfulnl_rcv_nl_event,
719 };
720
721 static int
722 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
723                   struct nlmsghdr *nlh, struct nfattr *nfqa[])
724 {
725         return -ENOTSUPP;
726 }
727
728 static struct nf_logger nfulnl_logger = {
729         .name   = "nfnetlink_log",
730         .logfn  = &nfulnl_log_packet,
731         .me     = THIS_MODULE,
732 };
733
734 static const int nfula_min[NFULA_MAX] = {
735         [NFULA_PACKET_HDR-1]    = sizeof(struct nfulnl_msg_packet_hdr),
736         [NFULA_MARK-1]          = sizeof(u_int32_t),
737         [NFULA_TIMESTAMP-1]     = sizeof(struct nfulnl_msg_packet_timestamp),
738         [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
739         [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
740         [NFULA_IFINDEX_PHYSINDEV-1]     = sizeof(u_int32_t),
741         [NFULA_IFINDEX_PHYSOUTDEV-1]    = sizeof(u_int32_t),
742         [NFULA_HWADDR-1]        = sizeof(struct nfulnl_msg_packet_hw),
743         [NFULA_PAYLOAD-1]       = 0,
744         [NFULA_PREFIX-1]        = 0,
745         [NFULA_UID-1]           = sizeof(u_int32_t),
746         [NFULA_SEQ-1]           = sizeof(u_int32_t),
747         [NFULA_SEQ_GLOBAL-1]    = sizeof(u_int32_t),
748 };
749
750 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
751         [NFULA_CFG_CMD-1]       = sizeof(struct nfulnl_msg_config_cmd),
752         [NFULA_CFG_MODE-1]      = sizeof(struct nfulnl_msg_config_mode),
753         [NFULA_CFG_TIMEOUT-1]   = sizeof(u_int32_t),
754         [NFULA_CFG_QTHRESH-1]   = sizeof(u_int32_t),
755         [NFULA_CFG_NLBUFSIZ-1]  = sizeof(u_int32_t),
756         [NFULA_CFG_FLAGS-1]     = sizeof(u_int16_t),
757 };
758
759 static int
760 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
761                    struct nlmsghdr *nlh, struct nfattr *nfula[])
762 {
763         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
764         u_int16_t group_num = ntohs(nfmsg->res_id);
765         struct nfulnl_instance *inst;
766         int ret = 0;
767
768         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
769
770         if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
771                 UDEBUG("bad attribute size\n");
772                 return -EINVAL;
773         }
774
775         inst = instance_lookup_get(group_num);
776         if (nfula[NFULA_CFG_CMD-1]) {
777                 u_int8_t pf = nfmsg->nfgen_family;
778                 struct nfulnl_msg_config_cmd *cmd;
779                 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
780                 UDEBUG("found CFG_CMD for\n");
781
782                 switch (cmd->command) {
783                 case NFULNL_CFG_CMD_BIND:
784                         if (inst) {
785                                 ret = -EBUSY;
786                                 goto out_put;
787                         }
788
789                         inst = instance_create(group_num,
790                                                NETLINK_CB(skb).pid);
791                         if (!inst) {
792                                 ret = -EINVAL;
793                                 goto out;
794                         }
795                         break;
796                 case NFULNL_CFG_CMD_UNBIND:
797                         if (!inst) {
798                                 ret = -ENODEV;
799                                 goto out;
800                         }
801
802                         if (inst->peer_pid != NETLINK_CB(skb).pid) {
803                                 ret = -EPERM;
804                                 goto out_put;
805                         }
806
807                         instance_destroy(inst);
808                         goto out;
809                 case NFULNL_CFG_CMD_PF_BIND:
810                         UDEBUG("registering log handler for pf=%u\n", pf);
811                         ret = nf_log_register(pf, &nfulnl_logger);
812                         break;
813                 case NFULNL_CFG_CMD_PF_UNBIND:
814                         UDEBUG("unregistering log handler for pf=%u\n", pf);
815                         /* This is a bug and a feature.  We cannot unregister
816                          * other handlers, like nfnetlink_inst can */
817                         nf_log_unregister_pf(pf);
818                         break;
819                 default:
820                         ret = -EINVAL;
821                         break;
822                 }
823
824                 if (!inst)
825                         goto out;
826         } else {
827                 if (!inst) {
828                         UDEBUG("no config command, and no instance for "
829                                 "group=%u pid=%u =>ENOENT\n",
830                                 group_num, NETLINK_CB(skb).pid);
831                         ret = -ENOENT;
832                         goto out;
833                 }
834
835                 if (inst->peer_pid != NETLINK_CB(skb).pid) {
836                         UDEBUG("no config command, and wrong pid\n");
837                         ret = -EPERM;
838                         goto out_put;
839                 }
840         }
841
842         if (nfula[NFULA_CFG_MODE-1]) {
843                 struct nfulnl_msg_config_mode *params;
844                 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
845
846                 nfulnl_set_mode(inst, params->copy_mode,
847                                 ntohl(params->copy_range));
848         }
849
850         if (nfula[NFULA_CFG_TIMEOUT-1]) {
851                 __be32 timeout =
852                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
853
854                 nfulnl_set_timeout(inst, ntohl(timeout));
855         }
856
857         if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
858                 __be32 nlbufsiz =
859                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
860
861                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
862         }
863
864         if (nfula[NFULA_CFG_QTHRESH-1]) {
865                 __be32 qthresh =
866                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
867
868                 nfulnl_set_qthresh(inst, ntohl(qthresh));
869         }
870
871         if (nfula[NFULA_CFG_FLAGS-1]) {
872                 __be16 flags =
873                         *(__be16 *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
874                 nfulnl_set_flags(inst, ntohs(flags));
875         }
876
877 out_put:
878         instance_put(inst);
879 out:
880         return ret;
881 }
882
883 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
884         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
885                                     .attr_count = NFULA_MAX, },
886         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
887                                     .attr_count = NFULA_CFG_MAX, },
888 };
889
890 static struct nfnetlink_subsystem nfulnl_subsys = {
891         .name           = "log",
892         .subsys_id      = NFNL_SUBSYS_ULOG,
893         .cb_count       = NFULNL_MSG_MAX,
894         .cb             = nfulnl_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 iter_state *st)
903 {
904         if (!st)
905                 return NULL;
906
907         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
908                 if (!hlist_empty(&instance_table[st->bucket]))
909                         return instance_table[st->bucket].first;
910         }
911         return NULL;
912 }
913
914 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
915 {
916         h = h->next;
917         while (!h) {
918                 if (++st->bucket >= INSTANCE_BUCKETS)
919                         return NULL;
920
921                 h = instance_table[st->bucket].first;
922         }
923         return h;
924 }
925
926 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
927 {
928         struct hlist_node *head;
929         head = get_first(st);
930
931         if (head)
932                 while (pos && (head = get_next(st, head)))
933                         pos--;
934         return pos ? NULL : head;
935 }
936
937 static void *seq_start(struct seq_file *seq, loff_t *pos)
938 {
939         read_lock_bh(&instances_lock);
940         return get_idx(seq->private, *pos);
941 }
942
943 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
944 {
945         (*pos)++;
946         return get_next(s->private, v);
947 }
948
949 static void seq_stop(struct seq_file *s, void *v)
950 {
951         read_unlock_bh(&instances_lock);
952 }
953
954 static int seq_show(struct seq_file *s, void *v)
955 {
956         const struct nfulnl_instance *inst = v;
957
958         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
959                           inst->group_num,
960                           inst->peer_pid, inst->qlen,
961                           inst->copy_mode, inst->copy_range,
962                           inst->flushtimeout, atomic_read(&inst->use));
963 }
964
965 static const struct seq_operations nful_seq_ops = {
966         .start  = seq_start,
967         .next   = seq_next,
968         .stop   = seq_stop,
969         .show   = seq_show,
970 };
971
972 static int nful_open(struct inode *inode, struct file *file)
973 {
974         struct seq_file *seq;
975         struct iter_state *is;
976         int ret;
977
978         is = kzalloc(sizeof(*is), GFP_KERNEL);
979         if (!is)
980                 return -ENOMEM;
981         ret = seq_open(file, &nful_seq_ops);
982         if (ret < 0)
983                 goto out_free;
984         seq = file->private_data;
985         seq->private = is;
986         return ret;
987 out_free:
988         kfree(is);
989         return ret;
990 }
991
992 static const struct file_operations nful_file_ops = {
993         .owner   = THIS_MODULE,
994         .open    = nful_open,
995         .read    = seq_read,
996         .llseek  = seq_lseek,
997         .release = seq_release_private,
998 };
999
1000 #endif /* PROC_FS */
1001
1002 static int __init nfnetlink_log_init(void)
1003 {
1004         int i, status = -ENOMEM;
1005 #ifdef CONFIG_PROC_FS
1006         struct proc_dir_entry *proc_nful;
1007 #endif
1008
1009         for (i = 0; i < INSTANCE_BUCKETS; i++)
1010                 INIT_HLIST_HEAD(&instance_table[i]);
1011
1012         /* it's not really all that important to have a random value, so
1013          * we can do this from the init function, even if there hasn't
1014          * been that much entropy yet */
1015         get_random_bytes(&hash_init, sizeof(hash_init));
1016
1017         netlink_register_notifier(&nfulnl_rtnl_notifier);
1018         status = nfnetlink_subsys_register(&nfulnl_subsys);
1019         if (status < 0) {
1020                 printk(KERN_ERR "log: failed to create netlink socket\n");
1021                 goto cleanup_netlink_notifier;
1022         }
1023
1024 #ifdef CONFIG_PROC_FS
1025         proc_nful = create_proc_entry("nfnetlink_log", 0440,
1026                                       proc_net_netfilter);
1027         if (!proc_nful)
1028                 goto cleanup_subsys;
1029         proc_nful->proc_fops = &nful_file_ops;
1030 #endif
1031         return status;
1032
1033 #ifdef CONFIG_PROC_FS
1034 cleanup_subsys:
1035         nfnetlink_subsys_unregister(&nfulnl_subsys);
1036 #endif
1037 cleanup_netlink_notifier:
1038         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1039         return status;
1040 }
1041
1042 static void __exit nfnetlink_log_fini(void)
1043 {
1044         nf_log_unregister(&nfulnl_logger);
1045 #ifdef CONFIG_PROC_FS
1046         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1047 #endif
1048         nfnetlink_subsys_unregister(&nfulnl_subsys);
1049         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1050 }
1051
1052 MODULE_DESCRIPTION("netfilter userspace logging");
1053 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1054 MODULE_LICENSE("GPL");
1055 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1056
1057 module_init(nfnetlink_log_init);
1058 module_exit(nfnetlink_log_fini);