[NETFILTER]: nfnetlink_log: fix some constants
[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  HZ      /* every second */
41 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
42 #define NFULNL_COPY_RANGE_MAX   0xFFFF  /* max packet size is limited by 16-bit struct nfattr nfa_len field */
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 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         if (!try_module_get(THIS_MODULE)) {
157                 kfree(inst);
158                 goto out_unlock;
159         }
160
161         INIT_HLIST_NODE(&inst->hlist);
162         spin_lock_init(&inst->lock);
163         /* needs to be two, since we _put() after creation */
164         atomic_set(&inst->use, 2);
165
166         setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
167
168         inst->peer_pid = pid;
169         inst->group_num = group_num;
170
171         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
172         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
173         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
174         inst->copy_mode         = NFULNL_COPY_PACKET;
175         inst->copy_range        = NFULNL_COPY_RANGE_MAX;
176
177         hlist_add_head(&inst->hlist,
178                        &instance_table[instance_hashfn(group_num)]);
179
180         UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
181                 inst->hlist.next);
182
183         write_unlock_bh(&instances_lock);
184
185         return inst;
186
187 out_unlock:
188         write_unlock_bh(&instances_lock);
189         return NULL;
190 }
191
192 static void __nfulnl_flush(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                 __nfulnl_flush(inst);
208         spin_unlock_bh(&inst->lock);
209
210         /* and finally put the refcount */
211         instance_put(inst);
212 }
213
214 static inline void
215 instance_destroy(struct nfulnl_instance *inst)
216 {
217         write_lock_bh(&instances_lock);
218         __instance_destroy(inst);
219         write_unlock_bh(&instances_lock);
220 }
221
222 static int
223 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
224                   unsigned int range)
225 {
226         int status = 0;
227
228         spin_lock_bh(&inst->lock);
229
230         switch (mode) {
231         case NFULNL_COPY_NONE:
232         case NFULNL_COPY_META:
233                 inst->copy_mode = mode;
234                 inst->copy_range = 0;
235                 break;
236
237         case NFULNL_COPY_PACKET:
238                 inst->copy_mode = mode;
239                 inst->copy_range = min_t(unsigned int,
240                                          range, NFULNL_COPY_RANGE_MAX);
241                 break;
242
243         default:
244                 status = -EINVAL;
245                 break;
246         }
247
248         spin_unlock_bh(&inst->lock);
249
250         return status;
251 }
252
253 static int
254 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
255 {
256         int status;
257
258         spin_lock_bh(&inst->lock);
259         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
260                 status = -ERANGE;
261         else if (nlbufsiz > 131072)
262                 status = -ERANGE;
263         else {
264                 inst->nlbufsiz = nlbufsiz;
265                 status = 0;
266         }
267         spin_unlock_bh(&inst->lock);
268
269         return status;
270 }
271
272 static int
273 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
274 {
275         spin_lock_bh(&inst->lock);
276         inst->flushtimeout = timeout;
277         spin_unlock_bh(&inst->lock);
278
279         return 0;
280 }
281
282 static int
283 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
284 {
285         spin_lock_bh(&inst->lock);
286         inst->qthreshold = qthresh;
287         spin_unlock_bh(&inst->lock);
288
289         return 0;
290 }
291
292 static int
293 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
294 {
295         spin_lock_bh(&inst->lock);
296         inst->flags = flags;
297         spin_unlock_bh(&inst->lock);
298
299         return 0;
300 }
301
302 static struct sk_buff *
303 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
304 {
305         struct sk_buff *skb;
306         unsigned int n;
307
308         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
309
310         /* alloc skb which should be big enough for a whole multipart
311          * message.  WARNING: has to be <= 128k due to slab restrictions */
312
313         n = max(inst_size, pkt_size);
314         skb = alloc_skb(n, GFP_ATOMIC);
315         if (!skb) {
316                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
317                         inst_size);
318
319                 if (n > pkt_size) {
320                         /* try to allocate only as much as we need for current
321                          * packet */
322
323                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
324                         if (!skb)
325                                 PRINTR("nfnetlink_log: can't even alloc %u "
326                                        "bytes\n", pkt_size);
327                 }
328         }
329
330         return skb;
331 }
332
333 static int
334 __nfulnl_send(struct nfulnl_instance *inst)
335 {
336         int status = -1;
337
338         if (inst->qlen > 1)
339                 NLMSG_PUT(inst->skb, 0, 0,
340                           NLMSG_DONE,
341                           sizeof(struct nfgenmsg));
342
343         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
344         if (status < 0) {
345                 UDEBUG("netlink_unicast() failed\n");
346                 /* FIXME: statistics */
347         }
348
349         inst->qlen = 0;
350         inst->skb = NULL;
351
352 nlmsg_failure:
353         return status;
354 }
355
356 static void
357 __nfulnl_flush(struct nfulnl_instance *inst)
358 {
359         /* timer holds a reference */
360         if (del_timer(&inst->timer))
361                 instance_put(inst);
362         if (inst->skb)
363                 __nfulnl_send(inst);
364 }
365
366 static void
367 nfulnl_timer(unsigned long data)
368 {
369         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
370
371         UDEBUG("timer function called, flushing buffer\n");
372
373         spin_lock_bh(&inst->lock);
374         if (inst->skb)
375                 __nfulnl_send(inst);
376         spin_unlock_bh(&inst->lock);
377         instance_put(inst);
378 }
379
380 /* This is an inline function, we don't really care about a long
381  * list of arguments */
382 static inline int
383 __build_packet_message(struct nfulnl_instance *inst,
384                         const struct sk_buff *skb,
385                         unsigned int data_len,
386                         unsigned int pf,
387                         unsigned int hooknum,
388                         const struct net_device *indev,
389                         const struct net_device *outdev,
390                         const struct nf_loginfo *li,
391                         const char *prefix, unsigned int plen)
392 {
393         struct nfulnl_msg_packet_hdr pmsg;
394         struct nlmsghdr *nlh;
395         struct nfgenmsg *nfmsg;
396         __be32 tmp_uint;
397         sk_buff_data_t old_tail = inst->skb->tail;
398
399         UDEBUG("entered\n");
400
401         nlh = NLMSG_PUT(inst->skb, 0, 0,
402                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
403                         sizeof(struct nfgenmsg));
404         nfmsg = NLMSG_DATA(nlh);
405         nfmsg->nfgen_family = pf;
406         nfmsg->version = NFNETLINK_V0;
407         nfmsg->res_id = htons(inst->group_num);
408
409         pmsg.hw_protocol        = skb->protocol;
410         pmsg.hook               = hooknum;
411
412         NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
413
414         if (prefix)
415                 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
416
417         if (indev) {
418                 tmp_uint = htonl(indev->ifindex);
419 #ifndef CONFIG_BRIDGE_NETFILTER
420                 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
421                         &tmp_uint);
422 #else
423                 if (pf == PF_BRIDGE) {
424                         /* Case 1: outdev is physical input device, we need to
425                          * look for bridge group (when called from
426                          * netfilter_bridge) */
427                         NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
428                                 sizeof(tmp_uint), &tmp_uint);
429                         /* this is the bridge group "brX" */
430                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
431                         NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
432                                 sizeof(tmp_uint), &tmp_uint);
433                 } else {
434                         /* Case 2: indev is bridge group, we need to look for
435                          * physical device (when called from ipv4) */
436                         NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
437                                 sizeof(tmp_uint), &tmp_uint);
438                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
439                                 tmp_uint =
440                                     htonl(skb->nf_bridge->physindev->ifindex);
441                                 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
442                                         sizeof(tmp_uint), &tmp_uint);
443                         }
444                 }
445 #endif
446         }
447
448         if (outdev) {
449                 tmp_uint = htonl(outdev->ifindex);
450 #ifndef CONFIG_BRIDGE_NETFILTER
451                 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
452                         &tmp_uint);
453 #else
454                 if (pf == PF_BRIDGE) {
455                         /* Case 1: outdev is physical output device, we need to
456                          * look for bridge group (when called from
457                          * netfilter_bridge) */
458                         NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
459                                 sizeof(tmp_uint), &tmp_uint);
460                         /* this is the bridge group "brX" */
461                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
462                         NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
463                                 sizeof(tmp_uint), &tmp_uint);
464                 } else {
465                         /* Case 2: indev is a bridge group, we need to look
466                          * for physical device (when called from ipv4) */
467                         NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
468                                 sizeof(tmp_uint), &tmp_uint);
469                         if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
470                                 tmp_uint =
471                                     htonl(skb->nf_bridge->physoutdev->ifindex);
472                                 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
473                                         sizeof(tmp_uint), &tmp_uint);
474                         }
475                 }
476 #endif
477         }
478
479         if (skb->mark) {
480                 tmp_uint = htonl(skb->mark);
481                 NLA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
482         }
483
484         if (indev && skb->dev) {
485                 struct nfulnl_msg_packet_hw phw;
486                 int len = dev_parse_header(skb, phw.hw_addr);
487                 if (len > 0) {
488                         phw.hw_addrlen = htons(len);
489                         NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
490                 }
491         }
492
493         if (skb->tstamp.tv64) {
494                 struct nfulnl_msg_packet_timestamp ts;
495                 struct timeval tv = ktime_to_timeval(skb->tstamp);
496                 ts.sec = cpu_to_be64(tv.tv_sec);
497                 ts.usec = cpu_to_be64(tv.tv_usec);
498
499                 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
500         }
501
502         /* UID */
503         if (skb->sk) {
504                 read_lock_bh(&skb->sk->sk_callback_lock);
505                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
506                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
507                         /* need to unlock here since NLA_PUT may goto */
508                         read_unlock_bh(&skb->sk->sk_callback_lock);
509                         NLA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
510                 } else
511                         read_unlock_bh(&skb->sk->sk_callback_lock);
512         }
513
514         /* local sequence number */
515         if (inst->flags & NFULNL_CFG_F_SEQ) {
516                 tmp_uint = htonl(inst->seq++);
517                 NLA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
518         }
519         /* global sequence number */
520         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
521                 tmp_uint = htonl(atomic_inc_return(&global_seq));
522                 NLA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
523         }
524
525         if (data_len) {
526                 struct nlattr *nla;
527                 int size = nla_attr_size(data_len);
528
529                 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
530                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
531                         goto nlmsg_failure;
532                 }
533
534                 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
535                 nla->nla_type = NFULA_PAYLOAD;
536                 nla->nla_len = size;
537
538                 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
539                         BUG();
540         }
541
542         nlh->nlmsg_len = inst->skb->tail - old_tail;
543         return 0;
544
545 nlmsg_failure:
546         UDEBUG("nlmsg_failure\n");
547 nla_put_failure:
548         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
549         return -1;
550 }
551
552 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
553
554 static struct nf_loginfo default_loginfo = {
555         .type =         NF_LOG_TYPE_ULOG,
556         .u = {
557                 .ulog = {
558                         .copy_len       = 0xffff,
559                         .group          = 0,
560                         .qthreshold     = 1,
561                 },
562         },
563 };
564
565 /* log handler for internal netfilter logging api */
566 static void
567 nfulnl_log_packet(unsigned int pf,
568                   unsigned int hooknum,
569                   const struct sk_buff *skb,
570                   const struct net_device *in,
571                   const struct net_device *out,
572                   const struct nf_loginfo *li_user,
573                   const char *prefix)
574 {
575         unsigned int size, data_len;
576         struct nfulnl_instance *inst;
577         const struct nf_loginfo *li;
578         unsigned int qthreshold;
579         unsigned int plen;
580
581         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
582                 li = li_user;
583         else
584                 li = &default_loginfo;
585
586         inst = instance_lookup_get(li->u.ulog.group);
587         if (!inst)
588                 return;
589
590         plen = 0;
591         if (prefix)
592                 plen = strlen(prefix) + 1;
593
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_ALIGN(sizeof(struct nfgenmsg))
598                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
599                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
600                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
601 #ifdef CONFIG_BRIDGE_NETFILTER
602                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
603                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
604 #endif
605                 + nla_total_size(sizeof(u_int32_t))     /* mark */
606                 + nla_total_size(sizeof(u_int32_t))     /* uid */
607                 + nla_total_size(plen)                  /* prefix */
608                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
609                 + nla_total_size(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 += nla_total_size(sizeof(u_int32_t));
617         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
618                 size += nla_total_size(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 += nla_total_size(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->skb &&
647             size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
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                 __nfulnl_flush(inst);
653         }
654
655         if (!inst->skb) {
656                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
657                 if (!inst->skb)
658                         goto alloc_failure;
659         }
660
661         UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
662         inst->qlen++;
663
664         __build_packet_message(inst, skb, data_len, pf,
665                                 hooknum, in, out, li, prefix, plen);
666
667         if (inst->qlen >= qthreshold)
668                 __nfulnl_flush(inst);
669         /* timer_pending always called within inst->lock, so there
670          * is no chance of a race here */
671         else if (!timer_pending(&inst->timer)) {
672                 instance_get(inst);
673                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
674                 add_timer(&inst->timer);
675         }
676
677 unlock_and_release:
678         spin_unlock_bh(&inst->lock);
679         instance_put(inst);
680         return;
681
682 alloc_failure:
683         UDEBUG("error allocating skb\n");
684         /* FIXME: statistics */
685         goto unlock_and_release;
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->net == &init_net) &&
708                                     (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 nlattr *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 struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
735         [NFULA_CFG_CMD]         = { .len = sizeof(struct nfulnl_msg_config_cmd) },
736         [NFULA_CFG_MODE]        = { .len = sizeof(struct nfulnl_msg_config_mode) },
737         [NFULA_CFG_TIMEOUT]     = { .type = NLA_U32 },
738         [NFULA_CFG_QTHRESH]     = { .type = NLA_U32 },
739         [NFULA_CFG_NLBUFSIZ]    = { .type = NLA_U32 },
740         [NFULA_CFG_FLAGS]       = { .type = NLA_U16 },
741 };
742
743 static int
744 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
745                    struct nlmsghdr *nlh, struct nlattr *nfula[])
746 {
747         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
748         u_int16_t group_num = ntohs(nfmsg->res_id);
749         struct nfulnl_instance *inst;
750         int ret = 0;
751
752         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
753
754         inst = instance_lookup_get(group_num);
755         if (nfula[NFULA_CFG_CMD]) {
756                 u_int8_t pf = nfmsg->nfgen_family;
757                 struct nfulnl_msg_config_cmd *cmd;
758                 cmd = nla_data(nfula[NFULA_CFG_CMD]);
759                 UDEBUG("found CFG_CMD for\n");
760
761                 switch (cmd->command) {
762                 case NFULNL_CFG_CMD_BIND:
763                         if (inst) {
764                                 ret = -EBUSY;
765                                 goto out_put;
766                         }
767
768                         inst = instance_create(group_num,
769                                                NETLINK_CB(skb).pid);
770                         if (!inst) {
771                                 ret = -EINVAL;
772                                 goto out;
773                         }
774                         break;
775                 case NFULNL_CFG_CMD_UNBIND:
776                         if (!inst) {
777                                 ret = -ENODEV;
778                                 goto out;
779                         }
780
781                         if (inst->peer_pid != NETLINK_CB(skb).pid) {
782                                 ret = -EPERM;
783                                 goto out_put;
784                         }
785
786                         instance_destroy(inst);
787                         goto out;
788                 case NFULNL_CFG_CMD_PF_BIND:
789                         UDEBUG("registering log handler for pf=%u\n", pf);
790                         ret = nf_log_register(pf, &nfulnl_logger);
791                         break;
792                 case NFULNL_CFG_CMD_PF_UNBIND:
793                         UDEBUG("unregistering log handler for pf=%u\n", pf);
794                         /* This is a bug and a feature.  We cannot unregister
795                          * other handlers, like nfnetlink_inst can */
796                         nf_log_unregister_pf(pf);
797                         break;
798                 default:
799                         ret = -EINVAL;
800                         break;
801                 }
802
803                 if (!inst)
804                         goto out;
805         } else {
806                 if (!inst) {
807                         UDEBUG("no config command, and no instance for "
808                                 "group=%u pid=%u =>ENOENT\n",
809                                 group_num, NETLINK_CB(skb).pid);
810                         ret = -ENOENT;
811                         goto out;
812                 }
813
814                 if (inst->peer_pid != NETLINK_CB(skb).pid) {
815                         UDEBUG("no config command, and wrong pid\n");
816                         ret = -EPERM;
817                         goto out_put;
818                 }
819         }
820
821         if (nfula[NFULA_CFG_MODE]) {
822                 struct nfulnl_msg_config_mode *params;
823                 params = nla_data(nfula[NFULA_CFG_MODE]);
824
825                 nfulnl_set_mode(inst, params->copy_mode,
826                                 ntohl(params->copy_range));
827         }
828
829         if (nfula[NFULA_CFG_TIMEOUT]) {
830                 __be32 timeout =
831                         *(__be32 *)nla_data(nfula[NFULA_CFG_TIMEOUT]);
832
833                 nfulnl_set_timeout(inst, ntohl(timeout));
834         }
835
836         if (nfula[NFULA_CFG_NLBUFSIZ]) {
837                 __be32 nlbufsiz =
838                         *(__be32 *)nla_data(nfula[NFULA_CFG_NLBUFSIZ]);
839
840                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
841         }
842
843         if (nfula[NFULA_CFG_QTHRESH]) {
844                 __be32 qthresh =
845                         *(__be32 *)nla_data(nfula[NFULA_CFG_QTHRESH]);
846
847                 nfulnl_set_qthresh(inst, ntohl(qthresh));
848         }
849
850         if (nfula[NFULA_CFG_FLAGS]) {
851                 __be16 flags =
852                         *(__be16 *)nla_data(nfula[NFULA_CFG_FLAGS]);
853                 nfulnl_set_flags(inst, ntohs(flags));
854         }
855
856 out_put:
857         instance_put(inst);
858 out:
859         return ret;
860 }
861
862 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
863         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
864                                     .attr_count = NFULA_MAX, },
865         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
866                                     .attr_count = NFULA_CFG_MAX,
867                                     .policy = nfula_cfg_policy },
868 };
869
870 static const struct nfnetlink_subsystem nfulnl_subsys = {
871         .name           = "log",
872         .subsys_id      = NFNL_SUBSYS_ULOG,
873         .cb_count       = NFULNL_MSG_MAX,
874         .cb             = nfulnl_cb,
875 };
876
877 #ifdef CONFIG_PROC_FS
878 struct iter_state {
879         unsigned int bucket;
880 };
881
882 static struct hlist_node *get_first(struct iter_state *st)
883 {
884         if (!st)
885                 return NULL;
886
887         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
888                 if (!hlist_empty(&instance_table[st->bucket]))
889                         return instance_table[st->bucket].first;
890         }
891         return NULL;
892 }
893
894 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
895 {
896         h = h->next;
897         while (!h) {
898                 if (++st->bucket >= INSTANCE_BUCKETS)
899                         return NULL;
900
901                 h = instance_table[st->bucket].first;
902         }
903         return h;
904 }
905
906 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
907 {
908         struct hlist_node *head;
909         head = get_first(st);
910
911         if (head)
912                 while (pos && (head = get_next(st, head)))
913                         pos--;
914         return pos ? NULL : head;
915 }
916
917 static void *seq_start(struct seq_file *seq, loff_t *pos)
918 {
919         read_lock_bh(&instances_lock);
920         return get_idx(seq->private, *pos);
921 }
922
923 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
924 {
925         (*pos)++;
926         return get_next(s->private, v);
927 }
928
929 static void seq_stop(struct seq_file *s, void *v)
930 {
931         read_unlock_bh(&instances_lock);
932 }
933
934 static int seq_show(struct seq_file *s, void *v)
935 {
936         const struct nfulnl_instance *inst = v;
937
938         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
939                           inst->group_num,
940                           inst->peer_pid, inst->qlen,
941                           inst->copy_mode, inst->copy_range,
942                           inst->flushtimeout, atomic_read(&inst->use));
943 }
944
945 static const struct seq_operations nful_seq_ops = {
946         .start  = seq_start,
947         .next   = seq_next,
948         .stop   = seq_stop,
949         .show   = seq_show,
950 };
951
952 static int nful_open(struct inode *inode, struct file *file)
953 {
954         struct seq_file *seq;
955         struct iter_state *is;
956         int ret;
957
958         is = kzalloc(sizeof(*is), GFP_KERNEL);
959         if (!is)
960                 return -ENOMEM;
961         ret = seq_open(file, &nful_seq_ops);
962         if (ret < 0)
963                 goto out_free;
964         seq = file->private_data;
965         seq->private = is;
966         return ret;
967 out_free:
968         kfree(is);
969         return ret;
970 }
971
972 static const struct file_operations nful_file_ops = {
973         .owner   = THIS_MODULE,
974         .open    = nful_open,
975         .read    = seq_read,
976         .llseek  = seq_lseek,
977         .release = seq_release_private,
978 };
979
980 #endif /* PROC_FS */
981
982 static int __init nfnetlink_log_init(void)
983 {
984         int i, status = -ENOMEM;
985 #ifdef CONFIG_PROC_FS
986         struct proc_dir_entry *proc_nful;
987 #endif
988
989         for (i = 0; i < INSTANCE_BUCKETS; i++)
990                 INIT_HLIST_HEAD(&instance_table[i]);
991
992         /* it's not really all that important to have a random value, so
993          * we can do this from the init function, even if there hasn't
994          * been that much entropy yet */
995         get_random_bytes(&hash_init, sizeof(hash_init));
996
997         netlink_register_notifier(&nfulnl_rtnl_notifier);
998         status = nfnetlink_subsys_register(&nfulnl_subsys);
999         if (status < 0) {
1000                 printk(KERN_ERR "log: failed to create netlink socket\n");
1001                 goto cleanup_netlink_notifier;
1002         }
1003
1004 #ifdef CONFIG_PROC_FS
1005         proc_nful = create_proc_entry("nfnetlink_log", 0440,
1006                                       proc_net_netfilter);
1007         if (!proc_nful)
1008                 goto cleanup_subsys;
1009         proc_nful->proc_fops = &nful_file_ops;
1010 #endif
1011         return status;
1012
1013 #ifdef CONFIG_PROC_FS
1014 cleanup_subsys:
1015         nfnetlink_subsys_unregister(&nfulnl_subsys);
1016 #endif
1017 cleanup_netlink_notifier:
1018         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1019         return status;
1020 }
1021
1022 static void __exit nfnetlink_log_fini(void)
1023 {
1024         nf_log_unregister(&nfulnl_logger);
1025 #ifdef CONFIG_PROC_FS
1026         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1027 #endif
1028         nfnetlink_subsys_unregister(&nfulnl_subsys);
1029         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1030 }
1031
1032 MODULE_DESCRIPTION("netfilter userspace logging");
1033 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1034 MODULE_LICENSE("GPL");
1035 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1036
1037 module_init(nfnetlink_log_init);
1038 module_exit(nfnetlink_log_fini);