Merge branch 'master'
[linux-2.6] / 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  */
15 #include <linux/module.h>
16 #include <linux/skbuff.h>
17 #include <linux/init.h>
18 #include <linux/ip.h>
19 #include <linux/ipv6.h>
20 #include <linux/netdevice.h>
21 #include <linux/netfilter.h>
22 #include <linux/netlink.h>
23 #include <linux/netfilter/nfnetlink.h>
24 #include <linux/netfilter/nfnetlink_log.h>
25 #include <linux/spinlock.h>
26 #include <linux/sysctl.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/list.h>
30 #include <linux/jhash.h>
31 #include <linux/random.h>
32 #include <net/sock.h>
33
34 #include <asm/atomic.h>
35
36 #ifdef CONFIG_BRIDGE_NETFILTER
37 #include "../bridge/br_private.h"
38 #endif
39
40 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
41 #define NFULNL_TIMEOUT_DEFAULT  100     /* every second */
42 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
43
44 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
45                                      printk(x, ## args); } while (0);
46
47 #if 0
48 #define UDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
49                                         __FILE__, __LINE__, __FUNCTION__,  \
50                                         ## args)
51 #else
52 #define UDEBUG(x, ...)
53 #endif
54
55 struct nfulnl_instance {
56         struct hlist_node hlist;        /* global list of instances */
57         spinlock_t lock;
58         atomic_t use;                   /* use count */
59
60         unsigned int qlen;              /* number of nlmsgs in skb */
61         struct sk_buff *skb;            /* pre-allocatd skb */
62         struct nlmsghdr *lastnlh;       /* netlink header of last msg in skb */
63         struct timer_list timer;
64         int peer_pid;                   /* PID of the peer process */
65
66         /* configurable parameters */
67         unsigned int flushtimeout;      /* timeout until queue flush */
68         unsigned int nlbufsiz;          /* netlink buffer allocation size */
69         unsigned int qthreshold;        /* threshold of the queue */
70         u_int32_t copy_range;
71         u_int16_t group_num;            /* number of this queue */
72         u_int8_t copy_mode;     
73 };
74
75 static DEFINE_RWLOCK(instances_lock);
76
77 #define INSTANCE_BUCKETS        16
78 static struct hlist_head instance_table[INSTANCE_BUCKETS];
79 static unsigned int hash_init;
80
81 static inline u_int8_t instance_hashfn(u_int16_t group_num)
82 {
83         return ((group_num & 0xff) % INSTANCE_BUCKETS);
84 }
85
86 static struct nfulnl_instance *
87 __instance_lookup(u_int16_t group_num)
88 {
89         struct hlist_head *head;
90         struct hlist_node *pos;
91         struct nfulnl_instance *inst;
92
93         UDEBUG("entering (group_num=%u)\n", group_num);
94
95         head = &instance_table[instance_hashfn(group_num)];
96         hlist_for_each_entry(inst, pos, head, hlist) {
97                 if (inst->group_num == group_num)
98                         return inst;
99         }
100         return NULL;
101 }
102
103 static inline void
104 instance_get(struct nfulnl_instance *inst)
105 {
106         atomic_inc(&inst->use);
107 }
108
109 static struct nfulnl_instance *
110 instance_lookup_get(u_int16_t group_num)
111 {
112         struct nfulnl_instance *inst;
113
114         read_lock_bh(&instances_lock);
115         inst = __instance_lookup(group_num);
116         if (inst)
117                 instance_get(inst);
118         read_unlock_bh(&instances_lock);
119
120         return inst;
121 }
122
123 static void
124 instance_put(struct nfulnl_instance *inst)
125 {
126         if (inst && atomic_dec_and_test(&inst->use)) {
127                 UDEBUG("kfree(inst=%p)\n", inst);
128                 kfree(inst);
129         }
130 }
131
132 static void nfulnl_timer(unsigned long data);
133
134 static struct nfulnl_instance *
135 instance_create(u_int16_t group_num, int pid)
136 {
137         struct nfulnl_instance *inst;
138
139         UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
140                 pid);
141
142         write_lock_bh(&instances_lock); 
143         if (__instance_lookup(group_num)) {
144                 inst = NULL;
145                 UDEBUG("aborting, instance already exists\n");
146                 goto out_unlock;
147         }
148
149         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
150         if (!inst)
151                 goto out_unlock;
152
153         INIT_HLIST_NODE(&inst->hlist);
154         spin_lock_init(&inst->lock);
155         /* needs to be two, since we _put() after creation */
156         atomic_set(&inst->use, 2);
157
158         init_timer(&inst->timer);
159         inst->timer.function = nfulnl_timer;
160         inst->timer.data = (unsigned long)inst;
161         /* don't start timer yet. (re)start it  with every packet */
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_destroy2(struct nfulnl_instance *inst, int lock)
196 {
197         /* first pull it out of the global list */
198         if (lock)
199                 write_lock_bh(&instances_lock);
200
201         UDEBUG("removing instance %p (queuenum=%u) from hash\n",
202                 inst, inst->group_num);
203
204         hlist_del(&inst->hlist);
205
206         if (lock)
207                 write_unlock_bh(&instances_lock);
208
209         /* then flush all pending packets from skb */
210
211         spin_lock_bh(&inst->lock);
212         if (inst->skb) {
213                 if (inst->qlen)
214                         __nfulnl_send(inst);
215                 if (inst->skb) {
216                         kfree_skb(inst->skb);
217                         inst->skb = NULL;
218                 }
219         }
220         spin_unlock_bh(&inst->lock);
221
222         /* and finally put the refcount */
223         instance_put(inst);
224
225         module_put(THIS_MODULE);
226 }
227
228 static inline void
229 __instance_destroy(struct nfulnl_instance *inst)
230 {
231         _instance_destroy2(inst, 0);
232 }
233
234 static inline void
235 instance_destroy(struct nfulnl_instance *inst)
236 {
237         _instance_destroy2(inst, 1);
238 }
239
240 static int
241 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
242                   unsigned int range)
243 {
244         int status = 0;
245
246         spin_lock_bh(&inst->lock);
247         
248         switch (mode) {
249         case NFULNL_COPY_NONE:
250         case NFULNL_COPY_META:
251                 inst->copy_mode = mode;
252                 inst->copy_range = 0;
253                 break;
254                 
255         case NFULNL_COPY_PACKET:
256                 inst->copy_mode = mode;
257                 /* we're using struct nfattr which has 16bit nfa_len */
258                 if (range > 0xffff)
259                         inst->copy_range = 0xffff;
260                 else
261                         inst->copy_range = range;
262                 break;
263                 
264         default:
265                 status = -EINVAL;
266                 break;
267         }
268
269         spin_unlock_bh(&inst->lock);
270
271         return status;
272 }
273
274 static int
275 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
276 {
277         int status;
278
279         spin_lock_bh(&inst->lock);
280         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
281                 status = -ERANGE;
282         else if (nlbufsiz > 131072)
283                 status = -ERANGE;
284         else {
285                 inst->nlbufsiz = nlbufsiz;
286                 status = 0;
287         }
288         spin_unlock_bh(&inst->lock);
289
290         return status;
291 }
292
293 static int
294 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
295 {
296         spin_lock_bh(&inst->lock);
297         inst->flushtimeout = timeout;
298         spin_unlock_bh(&inst->lock);
299
300         return 0;
301 }
302
303 static int
304 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
305 {
306         spin_lock_bh(&inst->lock);
307         inst->qthreshold = qthresh;
308         spin_unlock_bh(&inst->lock);
309
310         return 0;
311 }
312
313 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size, 
314                                         unsigned int pkt_size)
315 {
316         struct sk_buff *skb;
317         unsigned int n;
318
319         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
320
321         /* alloc skb which should be big enough for a whole multipart
322          * message.  WARNING: has to be <= 128k due to slab restrictions */
323
324         n = max(inst_size, pkt_size);
325         skb = alloc_skb(n, GFP_ATOMIC);
326         if (!skb) {
327                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
328                         inst_size);
329
330                 if (n > pkt_size) {
331                         /* try to allocate only as much as we need for current
332                          * packet */
333
334                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
335                         if (!skb)
336                                 PRINTR("nfnetlink_log: can't even alloc %u "
337                                        "bytes\n", pkt_size);
338                 }
339         }
340
341         return skb;
342 }
343
344 static int
345 __nfulnl_send(struct nfulnl_instance *inst)
346 {
347         int status;
348
349         if (timer_pending(&inst->timer))
350                 del_timer(&inst->timer);
351
352         if (inst->qlen > 1)
353                 inst->lastnlh->nlmsg_type = NLMSG_DONE;
354
355         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
356         if (status < 0) {
357                 UDEBUG("netlink_unicast() failed\n");
358                 /* FIXME: statistics */
359         }
360
361         inst->qlen = 0;
362         inst->skb = NULL;
363         inst->lastnlh = NULL;
364
365         return status;
366 }
367
368 static void nfulnl_timer(unsigned long data)
369 {
370         struct nfulnl_instance *inst = (struct nfulnl_instance *)data; 
371
372         UDEBUG("timer function called, flushing buffer\n");
373
374         spin_lock_bh(&inst->lock);
375         __nfulnl_send(inst);
376         instance_put(inst);
377         spin_unlock_bh(&inst->lock);
378 }
379
380 static inline int 
381 __build_packet_message(struct nfulnl_instance *inst,
382                         const struct sk_buff *skb, 
383                         unsigned int data_len,
384                         unsigned int pf,
385                         unsigned int hooknum,
386                         const struct net_device *indev,
387                         const struct net_device *outdev,
388                         const struct nf_loginfo *li,
389                         const char *prefix)
390 {
391         unsigned char *old_tail;
392         struct nfulnl_msg_packet_hdr pmsg;
393         struct nlmsghdr *nlh;
394         struct nfgenmsg *nfmsg;
395         u_int32_t tmp_uint;
396
397         UDEBUG("entered\n");
398                 
399         old_tail = inst->skb->tail;
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        = htons(skb->protocol);
409         pmsg.hook               = hooknum;
410
411         NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
412
413         if (prefix) {
414                 int slen = strlen(prefix);
415                 if (slen > NFULNL_PREFIXLEN)
416                         slen = NFULNL_PREFIXLEN;
417                 NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
418         }
419
420         if (indev) {
421                 tmp_uint = htonl(indev->ifindex);
422 #ifndef CONFIG_BRIDGE_NETFILTER
423                 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
424                         &tmp_uint);
425 #else
426                 if (pf == PF_BRIDGE) {
427                         /* Case 1: outdev is physical input device, we need to
428                          * look for bridge group (when called from
429                          * netfilter_bridge) */
430                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
431                                 sizeof(tmp_uint), &tmp_uint);
432                         /* this is the bridge group "brX" */
433                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
434                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
435                                 sizeof(tmp_uint), &tmp_uint);
436                 } else {
437                         /* Case 2: indev is bridge group, we need to look for
438                          * physical device (when called from ipv4) */
439                         NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
440                                 sizeof(tmp_uint), &tmp_uint);
441                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
442                                 tmp_uint = 
443                                     htonl(skb->nf_bridge->physindev->ifindex);
444                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
445                                         sizeof(tmp_uint), &tmp_uint);
446                         }
447                 }
448 #endif
449         }
450
451         if (outdev) {
452                 tmp_uint = htonl(outdev->ifindex);
453 #ifndef CONFIG_BRIDGE_NETFILTER
454                 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
455                         &tmp_uint);
456 #else
457                 if (pf == PF_BRIDGE) {
458                         /* Case 1: outdev is physical output device, we need to
459                          * look for bridge group (when called from
460                          * netfilter_bridge) */
461                         NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
462                                 sizeof(tmp_uint), &tmp_uint);
463                         /* this is the bridge group "brX" */
464                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
465                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
466                                 sizeof(tmp_uint), &tmp_uint);
467                 } else {
468                         /* Case 2: indev is a bridge group, we need to look
469                          * for physical device (when called from ipv4) */
470                         NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
471                                 sizeof(tmp_uint), &tmp_uint);
472                         if (skb->nf_bridge) {
473                                 tmp_uint = 
474                                     htonl(skb->nf_bridge->physoutdev->ifindex);
475                                 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
476                                         sizeof(tmp_uint), &tmp_uint);
477                         }
478                 }
479 #endif
480         }
481
482         if (skb->nfmark) {
483                 tmp_uint = htonl(skb->nfmark);
484                 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
485         }
486
487         if (indev && skb->dev && skb->dev->hard_header_parse) {
488                 struct nfulnl_msg_packet_hw phw;
489
490                 phw.hw_addrlen = 
491                         skb->dev->hard_header_parse((struct sk_buff *)skb, 
492                                                     phw.hw_addr);
493                 phw.hw_addrlen = htons(phw.hw_addrlen);
494                 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
495         }
496
497         if (skb->tstamp.off_sec) {
498                 struct nfulnl_msg_packet_timestamp ts;
499
500                 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
501                 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
502
503                 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
504         }
505
506         /* UID */
507         if (skb->sk) {
508                 read_lock_bh(&skb->sk->sk_callback_lock);
509                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
510                         u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
511                         /* need to unlock here since NFA_PUT may goto */
512                         read_unlock_bh(&skb->sk->sk_callback_lock);
513                         NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
514                 } else
515                         read_unlock_bh(&skb->sk->sk_callback_lock);
516         }
517
518         if (data_len) {
519                 struct nfattr *nfa;
520                 int size = NFA_LENGTH(data_len);
521
522                 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
523                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
524                         goto nlmsg_failure;
525                 }
526
527                 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
528                 nfa->nfa_type = NFULA_PAYLOAD;
529                 nfa->nfa_len = size;
530
531                 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
532                         BUG();
533         }
534                 
535         nlh->nlmsg_len = inst->skb->tail - old_tail;
536         return 0;
537
538 nlmsg_failure:
539         UDEBUG("nlmsg_failure\n");
540 nfattr_failure:
541         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
542         return -1;
543 }
544
545 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
546
547 static struct nf_loginfo default_loginfo = {
548         .type =         NF_LOG_TYPE_ULOG,
549         .u = {
550                 .ulog = {
551                         .copy_len       = 0xffff,
552                         .group          = 0,
553                         .qthreshold     = 1,
554                 },
555         },
556 };
557
558 /* log handler for internal netfilter logging api */
559 static void
560 nfulnl_log_packet(unsigned int pf,
561                   unsigned int hooknum,
562                   const struct sk_buff *skb,
563                   const struct net_device *in,
564                   const struct net_device *out,
565                   const struct nf_loginfo *li_user,
566                   const char *prefix)
567 {
568         unsigned int size, data_len;
569         struct nfulnl_instance *inst;
570         const struct nf_loginfo *li;
571         unsigned int qthreshold;
572         unsigned int nlbufsiz;
573
574         if (li_user && li_user->type == NF_LOG_TYPE_ULOG) 
575                 li = li_user;
576         else
577                 li = &default_loginfo;
578
579         inst = instance_lookup_get(li->u.ulog.group);
580         if (!inst)
581                 inst = instance_lookup_get(0);
582         if (!inst) {
583                 PRINTR("nfnetlink_log: trying to log packet, "
584                         "but no instance for group %u\n", li->u.ulog.group);
585                 return;
586         }
587
588         /* all macros expand to constant values at compile time */
589         /* FIXME: do we want to make the size calculation conditional based on
590          * what is actually present?  way more branches and checks, but more
591          * memory efficient... */
592         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
593                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
594                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
595                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
596 #ifdef CONFIG_BRIDGE_NETFILTER
597                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
598                 + NFA_SPACE(sizeof(u_int32_t))  /* ifindex */
599 #endif
600                 + NFA_SPACE(sizeof(u_int32_t))  /* mark */
601                 + NFA_SPACE(sizeof(u_int32_t))  /* uid */
602                 + NFA_SPACE(NFULNL_PREFIXLEN)   /* prefix */
603                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
604                 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
605
606         UDEBUG("initial size=%u\n", size);
607
608         spin_lock_bh(&inst->lock);
609
610         qthreshold = inst->qthreshold;
611         /* per-rule qthreshold overrides per-instance */
612         if (qthreshold > li->u.ulog.qthreshold)
613                 qthreshold = li->u.ulog.qthreshold;
614         
615         switch (inst->copy_mode) {
616         case NFULNL_COPY_META:
617         case NFULNL_COPY_NONE:
618                 data_len = 0;
619                 break;
620         
621         case NFULNL_COPY_PACKET:
622                 if (inst->copy_range == 0 
623                     || inst->copy_range > skb->len)
624                         data_len = skb->len;
625                 else
626                         data_len = inst->copy_range;
627                 
628                 size += NFA_SPACE(data_len);
629                 UDEBUG("copy_packet, therefore size now %u\n", size);
630                 break;
631         
632         default:
633                 spin_unlock_bh(&inst->lock);
634                 instance_put(inst);
635                 return;
636         }
637
638         if (size > inst->nlbufsiz)
639                 nlbufsiz = size;
640         else
641                 nlbufsiz = inst->nlbufsiz;
642
643         if (!inst->skb) {
644                 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
645                         UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
646                                 inst->nlbufsiz, size);
647                         goto alloc_failure;
648                 }
649         } else if (inst->qlen >= qthreshold ||
650                    size > skb_tailroom(inst->skb)) {
651                 /* either the queue len is too high or we don't have
652                  * enough room in the skb left. flush to userspace. */
653                 UDEBUG("flushing old skb\n");
654
655                 __nfulnl_send(inst);
656
657                 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
658                         UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
659                                 inst->nlbufsiz, size);
660                         goto alloc_failure;
661                 }
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);
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         spin_unlock_bh(&inst->lock);
678
679         return;
680
681 alloc_failure:
682         spin_unlock_bh(&inst->lock);
683         instance_put(inst);
684         UDEBUG("error allocating skb\n");
685         /* FIXME: statistics */
686 }
687
688 static int
689 nfulnl_rcv_nl_event(struct notifier_block *this,
690                    unsigned long event, void *ptr)
691 {
692         struct netlink_notify *n = ptr;
693
694         if (event == NETLINK_URELEASE &&
695             n->protocol == NETLINK_NETFILTER && n->pid) {
696                 int i;
697
698                 /* destroy all instances for this pid */
699                 write_lock_bh(&instances_lock);
700                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
701                         struct hlist_node *tmp, *t2;
702                         struct nfulnl_instance *inst;
703                         struct hlist_head *head = &instance_table[i];
704
705                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
706                                 UDEBUG("node = %p\n", inst);
707                                 if (n->pid == inst->peer_pid)
708                                         __instance_destroy(inst);
709                         }
710                 }
711                 write_unlock_bh(&instances_lock);
712         }
713         return NOTIFY_DONE;
714 }
715
716 static struct notifier_block nfulnl_rtnl_notifier = {
717         .notifier_call  = nfulnl_rcv_nl_event,
718 };
719
720 static int
721 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
722                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
723 {
724         return -ENOTSUPP;
725 }
726
727 static struct nf_logger nfulnl_logger = {
728         .name   = "nfnetlink_log",
729         .logfn  = &nfulnl_log_packet,
730         .me     = THIS_MODULE,
731 };
732
733 static const int nfula_min[NFULA_MAX] = {
734         [NFULA_PACKET_HDR-1]    = sizeof(struct nfulnl_msg_packet_hdr),
735         [NFULA_MARK-1]          = sizeof(u_int32_t),
736         [NFULA_TIMESTAMP-1]     = sizeof(struct nfulnl_msg_packet_timestamp),
737         [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
738         [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
739         [NFULA_HWADDR-1]        = sizeof(struct nfulnl_msg_packet_hw),
740         [NFULA_PAYLOAD-1]       = 0,
741         [NFULA_PREFIX-1]        = 0,
742         [NFULA_UID-1]           = sizeof(u_int32_t),
743 };
744
745 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
746         [NFULA_CFG_CMD-1]       = sizeof(struct nfulnl_msg_config_cmd),
747         [NFULA_CFG_MODE-1]      = sizeof(struct nfulnl_msg_config_mode),
748         [NFULA_CFG_TIMEOUT-1]   = sizeof(u_int32_t),
749         [NFULA_CFG_QTHRESH-1]   = sizeof(u_int32_t),
750         [NFULA_CFG_NLBUFSIZ-1]  = sizeof(u_int32_t),
751 };
752
753 static int
754 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
755                    struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
756 {
757         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
758         u_int16_t group_num = ntohs(nfmsg->res_id);
759         struct nfulnl_instance *inst;
760         int ret = 0;
761
762         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
763
764         if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
765                 UDEBUG("bad attribute size\n");
766                 return -EINVAL;
767         }
768
769         inst = instance_lookup_get(group_num);
770         if (nfula[NFULA_CFG_CMD-1]) {
771                 u_int8_t pf = nfmsg->nfgen_family;
772                 struct nfulnl_msg_config_cmd *cmd;
773                 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
774                 UDEBUG("found CFG_CMD for\n");
775
776                 switch (cmd->command) {
777                 case NFULNL_CFG_CMD_BIND:
778                         if (inst) {
779                                 ret = -EBUSY;
780                                 goto out_put;
781                         }
782
783                         inst = instance_create(group_num,
784                                                NETLINK_CB(skb).pid);
785                         if (!inst) {
786                                 ret = -EINVAL;
787                                 goto out_put;
788                         }
789                         break;
790                 case NFULNL_CFG_CMD_UNBIND:
791                         if (!inst) {
792                                 ret = -ENODEV;
793                                 goto out_put;
794                         }
795
796                         if (inst->peer_pid != NETLINK_CB(skb).pid) {
797                                 ret = -EPERM;
798                                 goto out_put;
799                         }
800
801                         instance_destroy(inst);
802                         break;
803                 case NFULNL_CFG_CMD_PF_BIND:
804                         UDEBUG("registering log handler for pf=%u\n", pf);
805                         ret = nf_log_register(pf, &nfulnl_logger);
806                         break;
807                 case NFULNL_CFG_CMD_PF_UNBIND:
808                         UDEBUG("unregistering log handler for pf=%u\n", pf);
809                         /* This is a bug and a feature.  We cannot unregister
810                          * other handlers, like nfnetlink_inst can */
811                         nf_log_unregister_pf(pf);
812                         break;
813                 default:
814                         ret = -EINVAL;
815                         break;
816                 }
817         } else {
818                 if (!inst) {
819                         UDEBUG("no config command, and no instance for "
820                                 "group=%u pid=%u =>ENOENT\n",
821                                 group_num, NETLINK_CB(skb).pid);
822                         ret = -ENOENT;
823                         goto out_put;
824                 }
825
826                 if (inst->peer_pid != NETLINK_CB(skb).pid) {
827                         UDEBUG("no config command, and wrong pid\n");
828                         ret = -EPERM;
829                         goto out_put;
830                 }
831         }
832
833         if (nfula[NFULA_CFG_MODE-1]) {
834                 struct nfulnl_msg_config_mode *params;
835                 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
836
837                 nfulnl_set_mode(inst, params->copy_mode,
838                                 ntohs(params->copy_range));
839         }
840
841         if (nfula[NFULA_CFG_TIMEOUT-1]) {
842                 u_int32_t timeout = 
843                         *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
844
845                 nfulnl_set_timeout(inst, ntohl(timeout));
846         }
847
848         if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
849                 u_int32_t nlbufsiz = 
850                         *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
851
852                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
853         }
854
855         if (nfula[NFULA_CFG_QTHRESH-1]) {
856                 u_int32_t qthresh = 
857                         *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
858
859                 nfulnl_set_qthresh(inst, ntohl(qthresh));
860         }
861
862 out_put:
863         instance_put(inst);
864         return ret;
865 }
866
867 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
868         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
869                                     .attr_count = NFULA_MAX, },
870         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
871                                     .attr_count = NFULA_CFG_MAX, },
872 };
873
874 static struct nfnetlink_subsystem nfulnl_subsys = {
875         .name           = "log",
876         .subsys_id      = NFNL_SUBSYS_ULOG,
877         .cb_count       = NFULNL_MSG_MAX,
878         .cb             = nfulnl_cb,
879 };
880
881 #ifdef CONFIG_PROC_FS
882 struct iter_state {
883         unsigned int bucket;
884 };
885
886 static struct hlist_node *get_first(struct seq_file *seq)
887 {
888         struct iter_state *st = seq->private;
889
890         if (!st)
891                 return NULL;
892
893         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
894                 if (!hlist_empty(&instance_table[st->bucket]))
895                         return instance_table[st->bucket].first;
896         }
897         return NULL;
898 }
899
900 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
901 {
902         struct iter_state *st = seq->private;
903
904         h = h->next;
905         while (!h) {
906                 if (++st->bucket >= INSTANCE_BUCKETS)
907                         return NULL;
908
909                 h = instance_table[st->bucket].first;
910         }
911         return h;
912 }
913
914 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
915 {
916         struct hlist_node *head;
917         head = get_first(seq);
918
919         if (head)
920                 while (pos && (head = get_next(seq, head)))
921                         pos--;
922         return pos ? NULL : head;
923 }
924
925 static void *seq_start(struct seq_file *seq, loff_t *pos)
926 {
927         read_lock_bh(&instances_lock);
928         return get_idx(seq, *pos);
929 }
930
931 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
932 {
933         (*pos)++;
934         return get_next(s, v);
935 }
936
937 static void seq_stop(struct seq_file *s, void *v)
938 {
939         read_unlock_bh(&instances_lock);
940 }
941
942 static int seq_show(struct seq_file *s, void *v)
943 {
944         const struct nfulnl_instance *inst = v;
945
946         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", 
947                           inst->group_num,
948                           inst->peer_pid, inst->qlen, 
949                           inst->copy_mode, inst->copy_range,
950                           inst->flushtimeout, atomic_read(&inst->use));
951 }
952
953 static struct seq_operations nful_seq_ops = {
954         .start  = seq_start,
955         .next   = seq_next,
956         .stop   = seq_stop,
957         .show   = seq_show,
958 };
959
960 static int nful_open(struct inode *inode, struct file *file)
961 {
962         struct seq_file *seq;
963         struct iter_state *is;
964         int ret;
965
966         is = kzalloc(sizeof(*is), GFP_KERNEL);
967         if (!is)
968                 return -ENOMEM;
969         ret = seq_open(file, &nful_seq_ops);
970         if (ret < 0)
971                 goto out_free;
972         seq = file->private_data;
973         seq->private = is;
974         return ret;
975 out_free:
976         kfree(is);
977         return ret;
978 }
979
980 static struct file_operations nful_file_ops = {
981         .owner   = THIS_MODULE,
982         .open    = nful_open,
983         .read    = seq_read,
984         .llseek  = seq_lseek,
985         .release = seq_release_private,
986 };
987
988 #endif /* PROC_FS */
989
990 static int
991 init_or_cleanup(int init)
992 {
993         int i, status = -ENOMEM;
994 #ifdef CONFIG_PROC_FS
995         struct proc_dir_entry *proc_nful;
996 #endif
997         
998         if (!init)
999                 goto cleanup;
1000
1001         for (i = 0; i < INSTANCE_BUCKETS; i++)
1002                 INIT_HLIST_HEAD(&instance_table[i]);
1003         
1004         /* it's not really all that important to have a random value, so
1005          * we can do this from the init function, even if there hasn't
1006          * been that much entropy yet */
1007         get_random_bytes(&hash_init, sizeof(hash_init));
1008
1009         netlink_register_notifier(&nfulnl_rtnl_notifier);
1010         status = nfnetlink_subsys_register(&nfulnl_subsys);
1011         if (status < 0) {
1012                 printk(KERN_ERR "log: failed to create netlink socket\n");
1013                 goto cleanup_netlink_notifier;
1014         }
1015
1016 #ifdef CONFIG_PROC_FS
1017         proc_nful = create_proc_entry("nfnetlink_log", 0440,
1018                                       proc_net_netfilter);
1019         if (!proc_nful)
1020                 goto cleanup_subsys;
1021         proc_nful->proc_fops = &nful_file_ops;
1022 #endif
1023
1024         return status;
1025
1026 cleanup:
1027         nf_log_unregister_logger(&nfulnl_logger);
1028 #ifdef CONFIG_PROC_FS
1029         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1030 cleanup_subsys:
1031 #endif
1032         nfnetlink_subsys_unregister(&nfulnl_subsys);
1033 cleanup_netlink_notifier:
1034         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1035         return status;
1036 }
1037
1038 static int __init init(void)
1039 {
1040         
1041         return init_or_cleanup(1);
1042 }
1043
1044 static void __exit fini(void)
1045 {
1046         init_or_cleanup(0);
1047 }
1048
1049 MODULE_DESCRIPTION("netfilter userspace logging");
1050 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1051 MODULE_LICENSE("GPL");
1052 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1053
1054 module_init(init);
1055 module_exit(fini);