[NETFILTER]: Remove changelogs and CVS IDs
[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         init_timer(&inst->timer);
162         inst->timer.function = nfulnl_timer;
163         inst->timer.data = (unsigned long)inst;
164         /* don't start timer yet. (re)start it  with every packet */
165
166         inst->peer_pid = pid;
167         inst->group_num = group_num;
168
169         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
170         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
171         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
172         inst->copy_mode         = NFULNL_COPY_PACKET;
173         inst->copy_range        = 0xffff;
174
175         if (!try_module_get(THIS_MODULE))
176                 goto out_free;
177
178         hlist_add_head(&inst->hlist,
179                        &instance_table[instance_hashfn(group_num)]);
180
181         UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
182                 inst->hlist.next);
183
184         write_unlock_bh(&instances_lock);
185
186         return inst;
187
188 out_free:
189         instance_put(inst);
190 out_unlock:
191         write_unlock_bh(&instances_lock);
192         return NULL;
193 }
194
195 static int __nfulnl_send(struct nfulnl_instance *inst);
196
197 static void
198 _instance_destroy2(struct nfulnl_instance *inst, int lock)
199 {
200         /* first pull it out of the global list */
201         if (lock)
202                 write_lock_bh(&instances_lock);
203
204         UDEBUG("removing instance %p (queuenum=%u) from hash\n",
205                 inst, inst->group_num);
206
207         hlist_del(&inst->hlist);
208
209         if (lock)
210                 write_unlock_bh(&instances_lock);
211
212         /* then flush all pending packets from skb */
213
214         spin_lock_bh(&inst->lock);
215         if (inst->skb) {
216                 /* timer "holds" one reference (we have one more) */
217                 if (del_timer(&inst->timer))
218                         instance_put(inst);
219                 if (inst->qlen)
220                         __nfulnl_send(inst);
221                 if (inst->skb) {
222                         kfree_skb(inst->skb);
223                         inst->skb = NULL;
224                 }
225         }
226         spin_unlock_bh(&inst->lock);
227
228         /* and finally put the refcount */
229         instance_put(inst);
230 }
231
232 static inline void
233 __instance_destroy(struct nfulnl_instance *inst)
234 {
235         _instance_destroy2(inst, 0);
236 }
237
238 static inline void
239 instance_destroy(struct nfulnl_instance *inst)
240 {
241         _instance_destroy2(inst, 1);
242 }
243
244 static int
245 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
246                   unsigned int range)
247 {
248         int status = 0;
249
250         spin_lock_bh(&inst->lock);
251
252         switch (mode) {
253         case NFULNL_COPY_NONE:
254         case NFULNL_COPY_META:
255                 inst->copy_mode = mode;
256                 inst->copy_range = 0;
257                 break;
258
259         case NFULNL_COPY_PACKET:
260                 inst->copy_mode = mode;
261                 /* we're using struct nfattr which has 16bit nfa_len */
262                 if (range > 0xffff)
263                         inst->copy_range = 0xffff;
264                 else
265                         inst->copy_range = range;
266                 break;
267
268         default:
269                 status = -EINVAL;
270                 break;
271         }
272
273         spin_unlock_bh(&inst->lock);
274
275         return status;
276 }
277
278 static int
279 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
280 {
281         int status;
282
283         spin_lock_bh(&inst->lock);
284         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
285                 status = -ERANGE;
286         else if (nlbufsiz > 131072)
287                 status = -ERANGE;
288         else {
289                 inst->nlbufsiz = nlbufsiz;
290                 status = 0;
291         }
292         spin_unlock_bh(&inst->lock);
293
294         return status;
295 }
296
297 static int
298 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
299 {
300         spin_lock_bh(&inst->lock);
301         inst->flushtimeout = timeout;
302         spin_unlock_bh(&inst->lock);
303
304         return 0;
305 }
306
307 static int
308 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
309 {
310         spin_lock_bh(&inst->lock);
311         inst->qthreshold = qthresh;
312         spin_unlock_bh(&inst->lock);
313
314         return 0;
315 }
316
317 static int
318 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
319 {
320         spin_lock_bh(&inst->lock);
321         inst->flags = flags;
322         spin_unlock_bh(&inst->lock);
323
324         return 0;
325 }
326
327 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
328                                         unsigned int pkt_size)
329 {
330         struct sk_buff *skb;
331         unsigned int n;
332
333         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
334
335         /* alloc skb which should be big enough for a whole multipart
336          * message.  WARNING: has to be <= 128k due to slab restrictions */
337
338         n = max(inst_size, pkt_size);
339         skb = alloc_skb(n, GFP_ATOMIC);
340         if (!skb) {
341                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
342                         inst_size);
343
344                 if (n > pkt_size) {
345                         /* try to allocate only as much as we need for current
346                          * packet */
347
348                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
349                         if (!skb)
350                                 PRINTR("nfnetlink_log: can't even alloc %u "
351                                        "bytes\n", pkt_size);
352                 }
353         }
354
355         return skb;
356 }
357
358 static int
359 __nfulnl_send(struct nfulnl_instance *inst)
360 {
361         int status;
362
363         if (!inst->skb)
364                 return 0;
365
366         if (inst->qlen > 1)
367                 inst->lastnlh->nlmsg_type = NLMSG_DONE;
368
369         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
370         if (status < 0) {
371                 UDEBUG("netlink_unicast() failed\n");
372                 /* FIXME: statistics */
373         }
374
375         inst->qlen = 0;
376         inst->skb = NULL;
377         inst->lastnlh = NULL;
378
379         return status;
380 }
381
382 static void nfulnl_timer(unsigned long data)
383 {
384         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
385
386         UDEBUG("timer function called, flushing buffer\n");
387
388         spin_lock_bh(&inst->lock);
389         __nfulnl_send(inst);
390         spin_unlock_bh(&inst->lock);
391         instance_put(inst);
392 }
393
394 /* This is an inline function, we don't really care about a long
395  * list of arguments */
396 static inline int
397 __build_packet_message(struct nfulnl_instance *inst,
398                         const struct sk_buff *skb,
399                         unsigned int data_len,
400                         unsigned int pf,
401                         unsigned int hooknum,
402                         const struct net_device *indev,
403                         const struct net_device *outdev,
404                         const struct nf_loginfo *li,
405                         const char *prefix, unsigned int plen)
406 {
407         struct nfulnl_msg_packet_hdr pmsg;
408         struct nlmsghdr *nlh;
409         struct nfgenmsg *nfmsg;
410         __be32 tmp_uint;
411         sk_buff_data_t old_tail = inst->skb->tail;
412
413         UDEBUG("entered\n");
414
415         nlh = NLMSG_PUT(inst->skb, 0, 0,
416                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
417                         sizeof(struct nfgenmsg));
418         nfmsg = NLMSG_DATA(nlh);
419         nfmsg->nfgen_family = pf;
420         nfmsg->version = NFNETLINK_V0;
421         nfmsg->res_id = htons(inst->group_num);
422
423         pmsg.hw_protocol        = skb->protocol;
424         pmsg.hook               = hooknum;
425
426         NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
427
428         if (prefix)
429                 NFA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
430
431         if (indev) {
432                 tmp_uint = htonl(indev->ifindex);
433 #ifndef CONFIG_BRIDGE_NETFILTER
434                 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
435                         &tmp_uint);
436 #else
437                 if (pf == PF_BRIDGE) {
438                         /* Case 1: outdev is physical input device, we need to
439                          * look for bridge group (when called from
440                          * netfilter_bridge) */
441                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
442                                 sizeof(tmp_uint), &tmp_uint);
443                         /* this is the bridge group "brX" */
444                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
445                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
446                                 sizeof(tmp_uint), &tmp_uint);
447                 } else {
448                         /* Case 2: indev is bridge group, we need to look for
449                          * physical device (when called from ipv4) */
450                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
451                                 sizeof(tmp_uint), &tmp_uint);
452                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
453                                 tmp_uint =
454                                     htonl(skb->nf_bridge->physindev->ifindex);
455                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
456                                         sizeof(tmp_uint), &tmp_uint);
457                         }
458                 }
459 #endif
460         }
461
462         if (outdev) {
463                 tmp_uint = htonl(outdev->ifindex);
464 #ifndef CONFIG_BRIDGE_NETFILTER
465                 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
466                         &tmp_uint);
467 #else
468                 if (pf == PF_BRIDGE) {
469                         /* Case 1: outdev is physical output device, we need to
470                          * look for bridge group (when called from
471                          * netfilter_bridge) */
472                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
473                                 sizeof(tmp_uint), &tmp_uint);
474                         /* this is the bridge group "brX" */
475                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
476                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
477                                 sizeof(tmp_uint), &tmp_uint);
478                 } else {
479                         /* Case 2: indev is a bridge group, we need to look
480                          * for physical device (when called from ipv4) */
481                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
482                                 sizeof(tmp_uint), &tmp_uint);
483                         if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
484                                 tmp_uint =
485                                     htonl(skb->nf_bridge->physoutdev->ifindex);
486                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
487                                         sizeof(tmp_uint), &tmp_uint);
488                         }
489                 }
490 #endif
491         }
492
493         if (skb->mark) {
494                 tmp_uint = htonl(skb->mark);
495                 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
496         }
497
498         if (indev && skb->dev && skb->dev->hard_header_parse) {
499                 struct nfulnl_msg_packet_hw phw;
500                 int len = skb->dev->hard_header_parse((struct sk_buff *)skb,
501                                                     phw.hw_addr);
502                 phw.hw_addrlen = htons(len);
503                 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
504         }
505
506         if (skb->tstamp.tv64) {
507                 struct nfulnl_msg_packet_timestamp ts;
508                 struct timeval tv = ktime_to_timeval(skb->tstamp);
509                 ts.sec = cpu_to_be64(tv.tv_sec);
510                 ts.usec = cpu_to_be64(tv.tv_usec);
511
512                 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
513         }
514
515         /* UID */
516         if (skb->sk) {
517                 read_lock_bh(&skb->sk->sk_callback_lock);
518                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
519                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
520                         /* need to unlock here since NFA_PUT may goto */
521                         read_unlock_bh(&skb->sk->sk_callback_lock);
522                         NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
523                 } else
524                         read_unlock_bh(&skb->sk->sk_callback_lock);
525         }
526
527         /* local sequence number */
528         if (inst->flags & NFULNL_CFG_F_SEQ) {
529                 tmp_uint = htonl(inst->seq++);
530                 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
531         }
532         /* global sequence number */
533         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
534                 tmp_uint = htonl(atomic_inc_return(&global_seq));
535                 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
536         }
537
538         if (data_len) {
539                 struct nfattr *nfa;
540                 int size = NFA_LENGTH(data_len);
541
542                 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
543                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
544                         goto nlmsg_failure;
545                 }
546
547                 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
548                 nfa->nfa_type = NFULA_PAYLOAD;
549                 nfa->nfa_len = size;
550
551                 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
552                         BUG();
553         }
554
555         nlh->nlmsg_len = inst->skb->tail - old_tail;
556         inst->lastnlh = nlh;
557         return 0;
558
559 nlmsg_failure:
560         UDEBUG("nlmsg_failure\n");
561 nfattr_failure:
562         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
563         return -1;
564 }
565
566 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
567
568 static struct nf_loginfo default_loginfo = {
569         .type =         NF_LOG_TYPE_ULOG,
570         .u = {
571                 .ulog = {
572                         .copy_len       = 0xffff,
573                         .group          = 0,
574                         .qthreshold     = 1,
575                 },
576         },
577 };
578
579 /* log handler for internal netfilter logging api */
580 static void
581 nfulnl_log_packet(unsigned int pf,
582                   unsigned int hooknum,
583                   const struct sk_buff *skb,
584                   const struct net_device *in,
585                   const struct net_device *out,
586                   const struct nf_loginfo *li_user,
587                   const char *prefix)
588 {
589         unsigned int size, data_len;
590         struct nfulnl_instance *inst;
591         const struct nf_loginfo *li;
592         unsigned int qthreshold;
593         unsigned int nlbufsiz;
594         unsigned int plen;
595
596         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
597                 li = li_user;
598         else
599                 li = &default_loginfo;
600
601         inst = instance_lookup_get(li->u.ulog.group);
602         if (!inst)
603                 inst = instance_lookup_get(0);
604         if (!inst) {
605                 PRINTR("nfnetlink_log: trying to log packet, "
606                         "but no instance for group %u\n", li->u.ulog.group);
607                 return;
608         }
609
610         plen = 0;
611         if (prefix)
612                 plen = strlen(prefix) + 1;
613
614         /* all macros expand to constant values at compile time */
615         /* FIXME: do we want to make the size calculation conditional based on
616          * what is actually present?  way more branches and checks, but more
617          * memory efficient... */
618         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
619                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
620                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
621                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
622 #ifdef CONFIG_BRIDGE_NETFILTER
623                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
624                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
625 #endif
626                 + NFA_SPACE(sizeof(u_int32_t))  /* mark */
627                 + NFA_SPACE(sizeof(u_int32_t))  /* uid */
628                 + NFA_SPACE(plen)               /* prefix */
629                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
630                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
631
632         UDEBUG("initial size=%u\n", size);
633
634         spin_lock_bh(&inst->lock);
635
636         if (inst->flags & NFULNL_CFG_F_SEQ)
637                 size += NFA_SPACE(sizeof(u_int32_t));
638         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
639                 size += NFA_SPACE(sizeof(u_int32_t));
640
641         qthreshold = inst->qthreshold;
642         /* per-rule qthreshold overrides per-instance */
643         if (qthreshold > li->u.ulog.qthreshold)
644                 qthreshold = li->u.ulog.qthreshold;
645
646         switch (inst->copy_mode) {
647         case NFULNL_COPY_META:
648         case NFULNL_COPY_NONE:
649                 data_len = 0;
650                 break;
651
652         case NFULNL_COPY_PACKET:
653                 if (inst->copy_range == 0
654                     || inst->copy_range > skb->len)
655                         data_len = skb->len;
656                 else
657                         data_len = inst->copy_range;
658
659                 size += NFA_SPACE(data_len);
660                 UDEBUG("copy_packet, therefore size now %u\n", size);
661                 break;
662
663         default:
664                 spin_unlock_bh(&inst->lock);
665                 instance_put(inst);
666                 return;
667         }
668
669         if (size > inst->nlbufsiz)
670                 nlbufsiz = size;
671         else
672                 nlbufsiz = inst->nlbufsiz;
673
674         if (!inst->skb) {
675                 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
676                         UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
677                                 inst->nlbufsiz, size);
678                         goto alloc_failure;
679                 }
680         } else if (inst->qlen >= qthreshold ||
681                    size > skb_tailroom(inst->skb)) {
682                 /* either the queue len is too high or we don't have
683                  * enough room in the skb left. flush to userspace. */
684                 UDEBUG("flushing old skb\n");
685
686                 /* timer "holds" one reference (we have another one) */
687                 if (del_timer(&inst->timer))
688                         instance_put(inst);
689                 __nfulnl_send(inst);
690
691                 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
692                         UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
693                                 inst->nlbufsiz, size);
694                         goto alloc_failure;
695                 }
696         }
697
698         UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
699         inst->qlen++;
700
701         __build_packet_message(inst, skb, data_len, pf,
702                                 hooknum, in, out, li, prefix, plen);
703
704         /* timer_pending always called within inst->lock, so there
705          * is no chance of a race here */
706         if (!timer_pending(&inst->timer)) {
707                 instance_get(inst);
708                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
709                 add_timer(&inst->timer);
710         }
711
712 unlock_and_release:
713         spin_unlock_bh(&inst->lock);
714         instance_put(inst);
715         return;
716
717 alloc_failure:
718         UDEBUG("error allocating skb\n");
719         /* FIXME: statistics */
720         goto unlock_and_release;
721 }
722
723 static int
724 nfulnl_rcv_nl_event(struct notifier_block *this,
725                    unsigned long event, void *ptr)
726 {
727         struct netlink_notify *n = ptr;
728
729         if (event == NETLINK_URELEASE &&
730             n->protocol == NETLINK_NETFILTER && n->pid) {
731                 int i;
732
733                 /* destroy all instances for this pid */
734                 write_lock_bh(&instances_lock);
735                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
736                         struct hlist_node *tmp, *t2;
737                         struct nfulnl_instance *inst;
738                         struct hlist_head *head = &instance_table[i];
739
740                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
741                                 UDEBUG("node = %p\n", inst);
742                                 if (n->pid == inst->peer_pid)
743                                         __instance_destroy(inst);
744                         }
745                 }
746                 write_unlock_bh(&instances_lock);
747         }
748         return NOTIFY_DONE;
749 }
750
751 static struct notifier_block nfulnl_rtnl_notifier = {
752         .notifier_call  = nfulnl_rcv_nl_event,
753 };
754
755 static int
756 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
757                   struct nlmsghdr *nlh, struct nfattr *nfqa[])
758 {
759         return -ENOTSUPP;
760 }
761
762 static struct nf_logger nfulnl_logger = {
763         .name   = "nfnetlink_log",
764         .logfn  = &nfulnl_log_packet,
765         .me     = THIS_MODULE,
766 };
767
768 static const int nfula_min[NFULA_MAX] = {
769         [NFULA_PACKET_HDR-1]    = sizeof(struct nfulnl_msg_packet_hdr),
770         [NFULA_MARK-1]          = sizeof(u_int32_t),
771         [NFULA_TIMESTAMP-1]     = sizeof(struct nfulnl_msg_packet_timestamp),
772         [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
773         [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
774         [NFULA_IFINDEX_PHYSINDEV-1]     = sizeof(u_int32_t),
775         [NFULA_IFINDEX_PHYSOUTDEV-1]    = sizeof(u_int32_t),
776         [NFULA_HWADDR-1]        = sizeof(struct nfulnl_msg_packet_hw),
777         [NFULA_PAYLOAD-1]       = 0,
778         [NFULA_PREFIX-1]        = 0,
779         [NFULA_UID-1]           = sizeof(u_int32_t),
780         [NFULA_SEQ-1]           = sizeof(u_int32_t),
781         [NFULA_SEQ_GLOBAL-1]    = sizeof(u_int32_t),
782 };
783
784 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
785         [NFULA_CFG_CMD-1]       = sizeof(struct nfulnl_msg_config_cmd),
786         [NFULA_CFG_MODE-1]      = sizeof(struct nfulnl_msg_config_mode),
787         [NFULA_CFG_TIMEOUT-1]   = sizeof(u_int32_t),
788         [NFULA_CFG_QTHRESH-1]   = sizeof(u_int32_t),
789         [NFULA_CFG_NLBUFSIZ-1]  = sizeof(u_int32_t),
790         [NFULA_CFG_FLAGS-1]     = sizeof(u_int16_t),
791 };
792
793 static int
794 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
795                    struct nlmsghdr *nlh, struct nfattr *nfula[])
796 {
797         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
798         u_int16_t group_num = ntohs(nfmsg->res_id);
799         struct nfulnl_instance *inst;
800         int ret = 0;
801
802         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
803
804         if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
805                 UDEBUG("bad attribute size\n");
806                 return -EINVAL;
807         }
808
809         inst = instance_lookup_get(group_num);
810         if (nfula[NFULA_CFG_CMD-1]) {
811                 u_int8_t pf = nfmsg->nfgen_family;
812                 struct nfulnl_msg_config_cmd *cmd;
813                 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
814                 UDEBUG("found CFG_CMD for\n");
815
816                 switch (cmd->command) {
817                 case NFULNL_CFG_CMD_BIND:
818                         if (inst) {
819                                 ret = -EBUSY;
820                                 goto out_put;
821                         }
822
823                         inst = instance_create(group_num,
824                                                NETLINK_CB(skb).pid);
825                         if (!inst) {
826                                 ret = -EINVAL;
827                                 goto out_put;
828                         }
829                         break;
830                 case NFULNL_CFG_CMD_UNBIND:
831                         if (!inst) {
832                                 ret = -ENODEV;
833                                 goto out_put;
834                         }
835
836                         if (inst->peer_pid != NETLINK_CB(skb).pid) {
837                                 ret = -EPERM;
838                                 goto out_put;
839                         }
840
841                         instance_destroy(inst);
842                         break;
843                 case NFULNL_CFG_CMD_PF_BIND:
844                         UDEBUG("registering log handler for pf=%u\n", pf);
845                         ret = nf_log_register(pf, &nfulnl_logger);
846                         break;
847                 case NFULNL_CFG_CMD_PF_UNBIND:
848                         UDEBUG("unregistering log handler for pf=%u\n", pf);
849                         /* This is a bug and a feature.  We cannot unregister
850                          * other handlers, like nfnetlink_inst can */
851                         nf_log_unregister_pf(pf);
852                         break;
853                 default:
854                         ret = -EINVAL;
855                         break;
856                 }
857
858                 if (!inst)
859                         goto out;
860         } else {
861                 if (!inst) {
862                         UDEBUG("no config command, and no instance for "
863                                 "group=%u pid=%u =>ENOENT\n",
864                                 group_num, NETLINK_CB(skb).pid);
865                         ret = -ENOENT;
866                         goto out_put;
867                 }
868
869                 if (inst->peer_pid != NETLINK_CB(skb).pid) {
870                         UDEBUG("no config command, and wrong pid\n");
871                         ret = -EPERM;
872                         goto out_put;
873                 }
874         }
875
876         if (nfula[NFULA_CFG_MODE-1]) {
877                 struct nfulnl_msg_config_mode *params;
878                 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
879
880                 nfulnl_set_mode(inst, params->copy_mode,
881                                 ntohl(params->copy_range));
882         }
883
884         if (nfula[NFULA_CFG_TIMEOUT-1]) {
885                 __be32 timeout =
886                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
887
888                 nfulnl_set_timeout(inst, ntohl(timeout));
889         }
890
891         if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
892                 __be32 nlbufsiz =
893                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
894
895                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
896         }
897
898         if (nfula[NFULA_CFG_QTHRESH-1]) {
899                 __be32 qthresh =
900                         *(__be32 *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
901
902                 nfulnl_set_qthresh(inst, ntohl(qthresh));
903         }
904
905         if (nfula[NFULA_CFG_FLAGS-1]) {
906                 __be16 flags =
907                         *(__be16 *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
908                 nfulnl_set_flags(inst, ntohs(flags));
909         }
910
911 out_put:
912         instance_put(inst);
913 out:
914         return ret;
915 }
916
917 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
918         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
919                                     .attr_count = NFULA_MAX, },
920         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
921                                     .attr_count = NFULA_CFG_MAX, },
922 };
923
924 static struct nfnetlink_subsystem nfulnl_subsys = {
925         .name           = "log",
926         .subsys_id      = NFNL_SUBSYS_ULOG,
927         .cb_count       = NFULNL_MSG_MAX,
928         .cb             = nfulnl_cb,
929 };
930
931 #ifdef CONFIG_PROC_FS
932 struct iter_state {
933         unsigned int bucket;
934 };
935
936 static struct hlist_node *get_first(struct seq_file *seq)
937 {
938         struct iter_state *st = seq->private;
939
940         if (!st)
941                 return NULL;
942
943         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
944                 if (!hlist_empty(&instance_table[st->bucket]))
945                         return instance_table[st->bucket].first;
946         }
947         return NULL;
948 }
949
950 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
951 {
952         struct iter_state *st = seq->private;
953
954         h = h->next;
955         while (!h) {
956                 if (++st->bucket >= INSTANCE_BUCKETS)
957                         return NULL;
958
959                 h = instance_table[st->bucket].first;
960         }
961         return h;
962 }
963
964 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
965 {
966         struct hlist_node *head;
967         head = get_first(seq);
968
969         if (head)
970                 while (pos && (head = get_next(seq, head)))
971                         pos--;
972         return pos ? NULL : head;
973 }
974
975 static void *seq_start(struct seq_file *seq, loff_t *pos)
976 {
977         read_lock_bh(&instances_lock);
978         return get_idx(seq, *pos);
979 }
980
981 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
982 {
983         (*pos)++;
984         return get_next(s, v);
985 }
986
987 static void seq_stop(struct seq_file *s, void *v)
988 {
989         read_unlock_bh(&instances_lock);
990 }
991
992 static int seq_show(struct seq_file *s, void *v)
993 {
994         const struct nfulnl_instance *inst = v;
995
996         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
997                           inst->group_num,
998                           inst->peer_pid, inst->qlen,
999                           inst->copy_mode, inst->copy_range,
1000                           inst->flushtimeout, atomic_read(&inst->use));
1001 }
1002
1003 static struct seq_operations nful_seq_ops = {
1004         .start  = seq_start,
1005         .next   = seq_next,
1006         .stop   = seq_stop,
1007         .show   = seq_show,
1008 };
1009
1010 static int nful_open(struct inode *inode, struct file *file)
1011 {
1012         struct seq_file *seq;
1013         struct iter_state *is;
1014         int ret;
1015
1016         is = kzalloc(sizeof(*is), GFP_KERNEL);
1017         if (!is)
1018                 return -ENOMEM;
1019         ret = seq_open(file, &nful_seq_ops);
1020         if (ret < 0)
1021                 goto out_free;
1022         seq = file->private_data;
1023         seq->private = is;
1024         return ret;
1025 out_free:
1026         kfree(is);
1027         return ret;
1028 }
1029
1030 static const struct file_operations nful_file_ops = {
1031         .owner   = THIS_MODULE,
1032         .open    = nful_open,
1033         .read    = seq_read,
1034         .llseek  = seq_lseek,
1035         .release = seq_release_private,
1036 };
1037
1038 #endif /* PROC_FS */
1039
1040 static int __init nfnetlink_log_init(void)
1041 {
1042         int i, status = -ENOMEM;
1043 #ifdef CONFIG_PROC_FS
1044         struct proc_dir_entry *proc_nful;
1045 #endif
1046
1047         for (i = 0; i < INSTANCE_BUCKETS; i++)
1048                 INIT_HLIST_HEAD(&instance_table[i]);
1049
1050         /* it's not really all that important to have a random value, so
1051          * we can do this from the init function, even if there hasn't
1052          * been that much entropy yet */
1053         get_random_bytes(&hash_init, sizeof(hash_init));
1054
1055         netlink_register_notifier(&nfulnl_rtnl_notifier);
1056         status = nfnetlink_subsys_register(&nfulnl_subsys);
1057         if (status < 0) {
1058                 printk(KERN_ERR "log: failed to create netlink socket\n");
1059                 goto cleanup_netlink_notifier;
1060         }
1061
1062 #ifdef CONFIG_PROC_FS
1063         proc_nful = create_proc_entry("nfnetlink_log", 0440,
1064                                       proc_net_netfilter);
1065         if (!proc_nful)
1066                 goto cleanup_subsys;
1067         proc_nful->proc_fops = &nful_file_ops;
1068 #endif
1069         return status;
1070
1071 #ifdef CONFIG_PROC_FS
1072 cleanup_subsys:
1073         nfnetlink_subsys_unregister(&nfulnl_subsys);
1074 #endif
1075 cleanup_netlink_notifier:
1076         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1077         return status;
1078 }
1079
1080 static void __exit nfnetlink_log_fini(void)
1081 {
1082         nf_log_unregister(&nfulnl_logger);
1083 #ifdef CONFIG_PROC_FS
1084         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1085 #endif
1086         nfnetlink_subsys_unregister(&nfulnl_subsys);
1087         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1088 }
1089
1090 MODULE_DESCRIPTION("netfilter userspace logging");
1091 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1092 MODULE_LICENSE("GPL");
1093 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1094
1095 module_init(nfnetlink_log_init);
1096 module_exit(nfnetlink_log_fini);