[NETFILTER]: nfnetlink_{queue,log}: return ENOTSUPP for unknown cfg commands
[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 #include <net/netfilter/nf_log.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  HZ      /* every second */
42 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
43 #define NFULNL_COPY_RANGE_MAX   0xFFFF  /* max packet size is limited by 16-bit struct nfattr nfa_len field */
44
45 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
46                                      printk(x, ## args); } while (0);
47
48 #if 0
49 #define UDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
50                                         __FILE__, __LINE__, __FUNCTION__,  \
51                                         ## args)
52 #else
53 #define UDEBUG(x, ...)
54 #endif
55
56 struct nfulnl_instance {
57         struct hlist_node hlist;        /* global list of instances */
58         spinlock_t lock;
59         atomic_t use;                   /* use count */
60
61         unsigned int qlen;              /* number of nlmsgs in skb */
62         struct sk_buff *skb;            /* pre-allocatd 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_int32_t seq;                  /* instance-local sequential counter */
72         u_int16_t group_num;            /* number of this queue */
73         u_int16_t flags;
74         u_int8_t copy_mode;
75 };
76
77 static DEFINE_RWLOCK(instances_lock);
78 static atomic_t global_seq;
79
80 #define INSTANCE_BUCKETS        16
81 static struct hlist_head instance_table[INSTANCE_BUCKETS];
82 static unsigned int hash_init;
83
84 static inline u_int8_t instance_hashfn(u_int16_t group_num)
85 {
86         return ((group_num & 0xff) % INSTANCE_BUCKETS);
87 }
88
89 static struct nfulnl_instance *
90 __instance_lookup(u_int16_t group_num)
91 {
92         struct hlist_head *head;
93         struct hlist_node *pos;
94         struct nfulnl_instance *inst;
95
96         UDEBUG("entering (group_num=%u)\n", group_num);
97
98         head = &instance_table[instance_hashfn(group_num)];
99         hlist_for_each_entry(inst, pos, head, hlist) {
100                 if (inst->group_num == group_num)
101                         return inst;
102         }
103         return NULL;
104 }
105
106 static inline void
107 instance_get(struct nfulnl_instance *inst)
108 {
109         atomic_inc(&inst->use);
110 }
111
112 static struct nfulnl_instance *
113 instance_lookup_get(u_int16_t group_num)
114 {
115         struct nfulnl_instance *inst;
116
117         read_lock_bh(&instances_lock);
118         inst = __instance_lookup(group_num);
119         if (inst)
120                 instance_get(inst);
121         read_unlock_bh(&instances_lock);
122
123         return inst;
124 }
125
126 static void
127 instance_put(struct nfulnl_instance *inst)
128 {
129         if (inst && atomic_dec_and_test(&inst->use)) {
130                 UDEBUG("kfree(inst=%p)\n", inst);
131                 kfree(inst);
132                 module_put(THIS_MODULE);
133         }
134 }
135
136 static void nfulnl_timer(unsigned long data);
137
138 static struct nfulnl_instance *
139 instance_create(u_int16_t group_num, int pid)
140 {
141         struct nfulnl_instance *inst;
142
143         UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
144                 pid);
145
146         write_lock_bh(&instances_lock);
147         if (__instance_lookup(group_num)) {
148                 inst = NULL;
149                 UDEBUG("aborting, instance already exists\n");
150                 goto out_unlock;
151         }
152
153         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
154         if (!inst)
155                 goto out_unlock;
156
157         if (!try_module_get(THIS_MODULE)) {
158                 kfree(inst);
159                 goto out_unlock;
160         }
161
162         INIT_HLIST_NODE(&inst->hlist);
163         spin_lock_init(&inst->lock);
164         /* needs to be two, since we _put() after creation */
165         atomic_set(&inst->use, 2);
166
167         setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
168
169         inst->peer_pid = pid;
170         inst->group_num = group_num;
171
172         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
173         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
174         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
175         inst->copy_mode         = NFULNL_COPY_PACKET;
176         inst->copy_range        = NFULNL_COPY_RANGE_MAX;
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_unlock:
189         write_unlock_bh(&instances_lock);
190         return NULL;
191 }
192
193 static void __nfulnl_flush(struct nfulnl_instance *inst);
194
195 static void
196 __instance_destroy(struct nfulnl_instance *inst)
197 {
198         /* first pull it out of the global list */
199         UDEBUG("removing instance %p (queuenum=%u) from hash\n",
200                 inst, inst->group_num);
201
202         hlist_del(&inst->hlist);
203
204         /* then flush all pending packets from skb */
205
206         spin_lock_bh(&inst->lock);
207         if (inst->skb)
208                 __nfulnl_flush(inst);
209         spin_unlock_bh(&inst->lock);
210
211         /* and finally put the refcount */
212         instance_put(inst);
213 }
214
215 static inline void
216 instance_destroy(struct nfulnl_instance *inst)
217 {
218         write_lock_bh(&instances_lock);
219         __instance_destroy(inst);
220         write_unlock_bh(&instances_lock);
221 }
222
223 static int
224 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
225                   unsigned int range)
226 {
227         int status = 0;
228
229         spin_lock_bh(&inst->lock);
230
231         switch (mode) {
232         case NFULNL_COPY_NONE:
233         case NFULNL_COPY_META:
234                 inst->copy_mode = mode;
235                 inst->copy_range = 0;
236                 break;
237
238         case NFULNL_COPY_PACKET:
239                 inst->copy_mode = mode;
240                 inst->copy_range = min_t(unsigned int,
241                                          range, NFULNL_COPY_RANGE_MAX);
242                 break;
243
244         default:
245                 status = -EINVAL;
246                 break;
247         }
248
249         spin_unlock_bh(&inst->lock);
250
251         return status;
252 }
253
254 static int
255 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
256 {
257         int status;
258
259         spin_lock_bh(&inst->lock);
260         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
261                 status = -ERANGE;
262         else if (nlbufsiz > 131072)
263                 status = -ERANGE;
264         else {
265                 inst->nlbufsiz = nlbufsiz;
266                 status = 0;
267         }
268         spin_unlock_bh(&inst->lock);
269
270         return status;
271 }
272
273 static int
274 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
275 {
276         spin_lock_bh(&inst->lock);
277         inst->flushtimeout = timeout;
278         spin_unlock_bh(&inst->lock);
279
280         return 0;
281 }
282
283 static int
284 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
285 {
286         spin_lock_bh(&inst->lock);
287         inst->qthreshold = qthresh;
288         spin_unlock_bh(&inst->lock);
289
290         return 0;
291 }
292
293 static int
294 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
295 {
296         spin_lock_bh(&inst->lock);
297         inst->flags = flags;
298         spin_unlock_bh(&inst->lock);
299
300         return 0;
301 }
302
303 static struct sk_buff *
304 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
305 {
306         struct sk_buff *skb;
307         unsigned int n;
308
309         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
310
311         /* alloc skb which should be big enough for a whole multipart
312          * message.  WARNING: has to be <= 128k due to slab restrictions */
313
314         n = max(inst_size, pkt_size);
315         skb = alloc_skb(n, GFP_ATOMIC);
316         if (!skb) {
317                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
318                         inst_size);
319
320                 if (n > pkt_size) {
321                         /* try to allocate only as much as we need for current
322                          * packet */
323
324                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
325                         if (!skb)
326                                 PRINTR("nfnetlink_log: can't even alloc %u "
327                                        "bytes\n", pkt_size);
328                 }
329         }
330
331         return skb;
332 }
333
334 static int
335 __nfulnl_send(struct nfulnl_instance *inst)
336 {
337         int status = -1;
338
339         if (inst->qlen > 1)
340                 NLMSG_PUT(inst->skb, 0, 0,
341                           NLMSG_DONE,
342                           sizeof(struct nfgenmsg));
343
344         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
345         if (status < 0) {
346                 UDEBUG("netlink_unicast() failed\n");
347                 /* FIXME: statistics */
348         }
349
350         inst->qlen = 0;
351         inst->skb = NULL;
352
353 nlmsg_failure:
354         return status;
355 }
356
357 static void
358 __nfulnl_flush(struct nfulnl_instance *inst)
359 {
360         /* timer holds a reference */
361         if (del_timer(&inst->timer))
362                 instance_put(inst);
363         if (inst->skb)
364                 __nfulnl_send(inst);
365 }
366
367 static void
368 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         if (inst->skb)
376                 __nfulnl_send(inst);
377         spin_unlock_bh(&inst->lock);
378         instance_put(inst);
379 }
380
381 /* This is an inline function, we don't really care about a long
382  * list of arguments */
383 static inline int
384 __build_packet_message(struct nfulnl_instance *inst,
385                         const struct sk_buff *skb,
386                         unsigned int data_len,
387                         unsigned int pf,
388                         unsigned int hooknum,
389                         const struct net_device *indev,
390                         const struct net_device *outdev,
391                         const struct nf_loginfo *li,
392                         const char *prefix, unsigned int plen)
393 {
394         struct nfulnl_msg_packet_hdr pmsg;
395         struct nlmsghdr *nlh;
396         struct nfgenmsg *nfmsg;
397         __be32 tmp_uint;
398         sk_buff_data_t old_tail = inst->skb->tail;
399
400         UDEBUG("entered\n");
401
402         nlh = NLMSG_PUT(inst->skb, 0, 0,
403                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
404                         sizeof(struct nfgenmsg));
405         nfmsg = NLMSG_DATA(nlh);
406         nfmsg->nfgen_family = pf;
407         nfmsg->version = NFNETLINK_V0;
408         nfmsg->res_id = htons(inst->group_num);
409
410         pmsg.hw_protocol        = skb->protocol;
411         pmsg.hook               = hooknum;
412
413         NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
414
415         if (prefix)
416                 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
417
418         if (indev) {
419                 tmp_uint = htonl(indev->ifindex);
420 #ifndef CONFIG_BRIDGE_NETFILTER
421                 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
422                         &tmp_uint);
423 #else
424                 if (pf == PF_BRIDGE) {
425                         /* Case 1: outdev is physical input device, we need to
426                          * look for bridge group (when called from
427                          * netfilter_bridge) */
428                         NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
429                                 sizeof(tmp_uint), &tmp_uint);
430                         /* this is the bridge group "brX" */
431                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
432                         NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
433                                 sizeof(tmp_uint), &tmp_uint);
434                 } else {
435                         /* Case 2: indev is bridge group, we need to look for
436                          * physical device (when called from ipv4) */
437                         NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
438                                 sizeof(tmp_uint), &tmp_uint);
439                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
440                                 tmp_uint =
441                                     htonl(skb->nf_bridge->physindev->ifindex);
442                                 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
443                                         sizeof(tmp_uint), &tmp_uint);
444                         }
445                 }
446 #endif
447         }
448
449         if (outdev) {
450                 tmp_uint = htonl(outdev->ifindex);
451 #ifndef CONFIG_BRIDGE_NETFILTER
452                 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
453                         &tmp_uint);
454 #else
455                 if (pf == PF_BRIDGE) {
456                         /* Case 1: outdev is physical output device, we need to
457                          * look for bridge group (when called from
458                          * netfilter_bridge) */
459                         NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
460                                 sizeof(tmp_uint), &tmp_uint);
461                         /* this is the bridge group "brX" */
462                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
463                         NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
464                                 sizeof(tmp_uint), &tmp_uint);
465                 } else {
466                         /* Case 2: indev is a bridge group, we need to look
467                          * for physical device (when called from ipv4) */
468                         NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
469                                 sizeof(tmp_uint), &tmp_uint);
470                         if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
471                                 tmp_uint =
472                                     htonl(skb->nf_bridge->physoutdev->ifindex);
473                                 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
474                                         sizeof(tmp_uint), &tmp_uint);
475                         }
476                 }
477 #endif
478         }
479
480         if (skb->mark) {
481                 tmp_uint = htonl(skb->mark);
482                 NLA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
483         }
484
485         if (indev && skb->dev) {
486                 struct nfulnl_msg_packet_hw phw;
487                 int len = dev_parse_header(skb, phw.hw_addr);
488                 if (len > 0) {
489                         phw.hw_addrlen = htons(len);
490                         NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
491                 }
492         }
493
494         if (skb->tstamp.tv64) {
495                 struct nfulnl_msg_packet_timestamp ts;
496                 struct timeval tv = ktime_to_timeval(skb->tstamp);
497                 ts.sec = cpu_to_be64(tv.tv_sec);
498                 ts.usec = cpu_to_be64(tv.tv_usec);
499
500                 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
501         }
502
503         /* UID */
504         if (skb->sk) {
505                 read_lock_bh(&skb->sk->sk_callback_lock);
506                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
507                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
508                         /* need to unlock here since NLA_PUT may goto */
509                         read_unlock_bh(&skb->sk->sk_callback_lock);
510                         NLA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
511                 } else
512                         read_unlock_bh(&skb->sk->sk_callback_lock);
513         }
514
515         /* local sequence number */
516         if (inst->flags & NFULNL_CFG_F_SEQ) {
517                 tmp_uint = htonl(inst->seq++);
518                 NLA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
519         }
520         /* global sequence number */
521         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
522                 tmp_uint = htonl(atomic_inc_return(&global_seq));
523                 NLA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
524         }
525
526         if (data_len) {
527                 struct nlattr *nla;
528                 int size = nla_attr_size(data_len);
529
530                 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
531                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
532                         goto nlmsg_failure;
533                 }
534
535                 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
536                 nla->nla_type = NFULA_PAYLOAD;
537                 nla->nla_len = size;
538
539                 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
540                         BUG();
541         }
542
543         nlh->nlmsg_len = inst->skb->tail - old_tail;
544         return 0;
545
546 nlmsg_failure:
547         UDEBUG("nlmsg_failure\n");
548 nla_put_failure:
549         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
550         return -1;
551 }
552
553 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
554
555 static struct nf_loginfo default_loginfo = {
556         .type =         NF_LOG_TYPE_ULOG,
557         .u = {
558                 .ulog = {
559                         .copy_len       = 0xffff,
560                         .group          = 0,
561                         .qthreshold     = 1,
562                 },
563         },
564 };
565
566 /* log handler for internal netfilter logging api */
567 static void
568 nfulnl_log_packet(unsigned int pf,
569                   unsigned int hooknum,
570                   const struct sk_buff *skb,
571                   const struct net_device *in,
572                   const struct net_device *out,
573                   const struct nf_loginfo *li_user,
574                   const char *prefix)
575 {
576         unsigned int size, data_len;
577         struct nfulnl_instance *inst;
578         const struct nf_loginfo *li;
579         unsigned int qthreshold;
580         unsigned int plen;
581
582         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
583                 li = li_user;
584         else
585                 li = &default_loginfo;
586
587         inst = instance_lookup_get(li->u.ulog.group);
588         if (!inst)
589                 return;
590
591         plen = 0;
592         if (prefix)
593                 plen = strlen(prefix) + 1;
594
595         /* FIXME: do we want to make the size calculation conditional based on
596          * what is actually present?  way more branches and checks, but more
597          * memory efficient... */
598         size =    NLMSG_ALIGN(sizeof(struct nfgenmsg))
599                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
600                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
601                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
602 #ifdef CONFIG_BRIDGE_NETFILTER
603                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
604                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
605 #endif
606                 + nla_total_size(sizeof(u_int32_t))     /* mark */
607                 + nla_total_size(sizeof(u_int32_t))     /* uid */
608                 + nla_total_size(plen)                  /* prefix */
609                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
610                 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
611
612         UDEBUG("initial size=%u\n", size);
613
614         spin_lock_bh(&inst->lock);
615
616         if (inst->flags & NFULNL_CFG_F_SEQ)
617                 size += nla_total_size(sizeof(u_int32_t));
618         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
619                 size += nla_total_size(sizeof(u_int32_t));
620
621         qthreshold = inst->qthreshold;
622         /* per-rule qthreshold overrides per-instance */
623         if (qthreshold > li->u.ulog.qthreshold)
624                 qthreshold = li->u.ulog.qthreshold;
625
626         switch (inst->copy_mode) {
627         case NFULNL_COPY_META:
628         case NFULNL_COPY_NONE:
629                 data_len = 0;
630                 break;
631
632         case NFULNL_COPY_PACKET:
633                 if (inst->copy_range == 0
634                     || inst->copy_range > skb->len)
635                         data_len = skb->len;
636                 else
637                         data_len = inst->copy_range;
638
639                 size += nla_total_size(data_len);
640                 UDEBUG("copy_packet, therefore size now %u\n", size);
641                 break;
642
643         default:
644                 goto unlock_and_release;
645         }
646
647         if (inst->skb &&
648             size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
649                 /* either the queue len is too high or we don't have
650                  * enough room in the skb left. flush to userspace. */
651                 UDEBUG("flushing old skb\n");
652
653                 __nfulnl_flush(inst);
654         }
655
656         if (!inst->skb) {
657                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
658                 if (!inst->skb)
659                         goto alloc_failure;
660         }
661
662         UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
663         inst->qlen++;
664
665         __build_packet_message(inst, skb, data_len, pf,
666                                 hooknum, in, out, li, prefix, plen);
667
668         if (inst->qlen >= qthreshold)
669                 __nfulnl_flush(inst);
670         /* timer_pending always called within inst->lock, so there
671          * is no chance of a race here */
672         else if (!timer_pending(&inst->timer)) {
673                 instance_get(inst);
674                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
675                 add_timer(&inst->timer);
676         }
677
678 unlock_and_release:
679         spin_unlock_bh(&inst->lock);
680         instance_put(inst);
681         return;
682
683 alloc_failure:
684         UDEBUG("error allocating skb\n");
685         /* FIXME: statistics */
686         goto unlock_and_release;
687 }
688
689 static int
690 nfulnl_rcv_nl_event(struct notifier_block *this,
691                    unsigned long event, void *ptr)
692 {
693         struct netlink_notify *n = ptr;
694
695         if (event == NETLINK_URELEASE &&
696             n->protocol == NETLINK_NETFILTER && n->pid) {
697                 int i;
698
699                 /* destroy all instances for this pid */
700                 write_lock_bh(&instances_lock);
701                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
702                         struct hlist_node *tmp, *t2;
703                         struct nfulnl_instance *inst;
704                         struct hlist_head *head = &instance_table[i];
705
706                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
707                                 UDEBUG("node = %p\n", inst);
708                                 if ((n->net == &init_net) &&
709                                     (n->pid == inst->peer_pid))
710                                         __instance_destroy(inst);
711                         }
712                 }
713                 write_unlock_bh(&instances_lock);
714         }
715         return NOTIFY_DONE;
716 }
717
718 static struct notifier_block nfulnl_rtnl_notifier = {
719         .notifier_call  = nfulnl_rcv_nl_event,
720 };
721
722 static int
723 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
724                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
725 {
726         return -ENOTSUPP;
727 }
728
729 static const struct nf_logger nfulnl_logger = {
730         .name   = "nfnetlink_log",
731         .logfn  = &nfulnl_log_packet,
732         .me     = THIS_MODULE,
733 };
734
735 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
736         [NFULA_CFG_CMD]         = { .len = sizeof(struct nfulnl_msg_config_cmd) },
737         [NFULA_CFG_MODE]        = { .len = sizeof(struct nfulnl_msg_config_mode) },
738         [NFULA_CFG_TIMEOUT]     = { .type = NLA_U32 },
739         [NFULA_CFG_QTHRESH]     = { .type = NLA_U32 },
740         [NFULA_CFG_NLBUFSIZ]    = { .type = NLA_U32 },
741         [NFULA_CFG_FLAGS]       = { .type = NLA_U16 },
742 };
743
744 static int
745 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
746                    struct nlmsghdr *nlh, struct nlattr *nfula[])
747 {
748         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
749         u_int16_t group_num = ntohs(nfmsg->res_id);
750         struct nfulnl_instance *inst;
751         int ret = 0;
752
753         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
754
755         inst = instance_lookup_get(group_num);
756         if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
757                 ret = -EPERM;
758                 goto out_put;
759         }
760
761         if (nfula[NFULA_CFG_CMD]) {
762                 u_int8_t pf = nfmsg->nfgen_family;
763                 struct nfulnl_msg_config_cmd *cmd;
764
765                 cmd = nla_data(nfula[NFULA_CFG_CMD]);
766                 UDEBUG("found CFG_CMD for\n");
767
768                 switch (cmd->command) {
769                 case NFULNL_CFG_CMD_BIND:
770                         if (inst) {
771                                 ret = -EBUSY;
772                                 goto out_put;
773                         }
774
775                         inst = instance_create(group_num,
776                                                NETLINK_CB(skb).pid);
777                         if (!inst) {
778                                 ret = -EINVAL;
779                                 goto out;
780                         }
781                         break;
782                 case NFULNL_CFG_CMD_UNBIND:
783                         if (!inst) {
784                                 ret = -ENODEV;
785                                 goto out;
786                         }
787
788                         instance_destroy(inst);
789                         goto out;
790                 case NFULNL_CFG_CMD_PF_BIND:
791                         UDEBUG("registering log handler for pf=%u\n", pf);
792                         ret = nf_log_register(pf, &nfulnl_logger);
793                         break;
794                 case NFULNL_CFG_CMD_PF_UNBIND:
795                         UDEBUG("unregistering log handler for pf=%u\n", pf);
796                         /* This is a bug and a feature.  We cannot unregister
797                          * other handlers, like nfnetlink_inst can */
798                         nf_log_unregister_pf(pf);
799                         break;
800                 default:
801                         ret = -ENOTSUPP;
802                         break;
803                 }
804         }
805
806         if (nfula[NFULA_CFG_MODE]) {
807                 struct nfulnl_msg_config_mode *params;
808                 params = nla_data(nfula[NFULA_CFG_MODE]);
809
810                 if (!inst) {
811                         ret = -ENODEV;
812                         goto out;
813                 }
814                 nfulnl_set_mode(inst, params->copy_mode,
815                                 ntohl(params->copy_range));
816         }
817
818         if (nfula[NFULA_CFG_TIMEOUT]) {
819                 __be32 timeout =
820                         *(__be32 *)nla_data(nfula[NFULA_CFG_TIMEOUT]);
821
822                 if (!inst) {
823                         ret = -ENODEV;
824                         goto out;
825                 }
826                 nfulnl_set_timeout(inst, ntohl(timeout));
827         }
828
829         if (nfula[NFULA_CFG_NLBUFSIZ]) {
830                 __be32 nlbufsiz =
831                         *(__be32 *)nla_data(nfula[NFULA_CFG_NLBUFSIZ]);
832
833                 if (!inst) {
834                         ret = -ENODEV;
835                         goto out;
836                 }
837                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
838         }
839
840         if (nfula[NFULA_CFG_QTHRESH]) {
841                 __be32 qthresh =
842                         *(__be32 *)nla_data(nfula[NFULA_CFG_QTHRESH]);
843
844                 if (!inst) {
845                         ret = -ENODEV;
846                         goto out;
847                 }
848                 nfulnl_set_qthresh(inst, ntohl(qthresh));
849         }
850
851         if (nfula[NFULA_CFG_FLAGS]) {
852                 __be16 flags =
853                         *(__be16 *)nla_data(nfula[NFULA_CFG_FLAGS]);
854
855                 if (!inst) {
856                         ret = -ENODEV;
857                         goto out;
858                 }
859                 nfulnl_set_flags(inst, ntohs(flags));
860         }
861
862 out_put:
863         instance_put(inst);
864 out:
865         return ret;
866 }
867
868 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
869         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
870                                     .attr_count = NFULA_MAX, },
871         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
872                                     .attr_count = NFULA_CFG_MAX,
873                                     .policy = nfula_cfg_policy },
874 };
875
876 static const struct nfnetlink_subsystem nfulnl_subsys = {
877         .name           = "log",
878         .subsys_id      = NFNL_SUBSYS_ULOG,
879         .cb_count       = NFULNL_MSG_MAX,
880         .cb             = nfulnl_cb,
881 };
882
883 #ifdef CONFIG_PROC_FS
884 struct iter_state {
885         unsigned int bucket;
886 };
887
888 static struct hlist_node *get_first(struct iter_state *st)
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 iter_state *st, struct hlist_node *h)
901 {
902         h = h->next;
903         while (!h) {
904                 if (++st->bucket >= INSTANCE_BUCKETS)
905                         return NULL;
906
907                 h = instance_table[st->bucket].first;
908         }
909         return h;
910 }
911
912 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
913 {
914         struct hlist_node *head;
915         head = get_first(st);
916
917         if (head)
918                 while (pos && (head = get_next(st, head)))
919                         pos--;
920         return pos ? NULL : head;
921 }
922
923 static void *seq_start(struct seq_file *seq, loff_t *pos)
924 {
925         read_lock_bh(&instances_lock);
926         return get_idx(seq->private, *pos);
927 }
928
929 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
930 {
931         (*pos)++;
932         return get_next(s->private, v);
933 }
934
935 static void seq_stop(struct seq_file *s, void *v)
936 {
937         read_unlock_bh(&instances_lock);
938 }
939
940 static int seq_show(struct seq_file *s, void *v)
941 {
942         const struct nfulnl_instance *inst = v;
943
944         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
945                           inst->group_num,
946                           inst->peer_pid, inst->qlen,
947                           inst->copy_mode, inst->copy_range,
948                           inst->flushtimeout, atomic_read(&inst->use));
949 }
950
951 static const struct seq_operations nful_seq_ops = {
952         .start  = seq_start,
953         .next   = seq_next,
954         .stop   = seq_stop,
955         .show   = seq_show,
956 };
957
958 static int nful_open(struct inode *inode, struct file *file)
959 {
960         return seq_open_private(file, &nful_seq_ops,
961                         sizeof(struct iter_state));
962 }
963
964 static const struct file_operations nful_file_ops = {
965         .owner   = THIS_MODULE,
966         .open    = nful_open,
967         .read    = seq_read,
968         .llseek  = seq_lseek,
969         .release = seq_release_private,
970 };
971
972 #endif /* PROC_FS */
973
974 static int __init nfnetlink_log_init(void)
975 {
976         int i, status = -ENOMEM;
977 #ifdef CONFIG_PROC_FS
978         struct proc_dir_entry *proc_nful;
979 #endif
980
981         for (i = 0; i < INSTANCE_BUCKETS; i++)
982                 INIT_HLIST_HEAD(&instance_table[i]);
983
984         /* it's not really all that important to have a random value, so
985          * we can do this from the init function, even if there hasn't
986          * been that much entropy yet */
987         get_random_bytes(&hash_init, sizeof(hash_init));
988
989         netlink_register_notifier(&nfulnl_rtnl_notifier);
990         status = nfnetlink_subsys_register(&nfulnl_subsys);
991         if (status < 0) {
992                 printk(KERN_ERR "log: failed to create netlink socket\n");
993                 goto cleanup_netlink_notifier;
994         }
995
996 #ifdef CONFIG_PROC_FS
997         proc_nful = create_proc_entry("nfnetlink_log", 0440,
998                                       proc_net_netfilter);
999         if (!proc_nful)
1000                 goto cleanup_subsys;
1001         proc_nful->proc_fops = &nful_file_ops;
1002 #endif
1003         return status;
1004
1005 #ifdef CONFIG_PROC_FS
1006 cleanup_subsys:
1007         nfnetlink_subsys_unregister(&nfulnl_subsys);
1008 #endif
1009 cleanup_netlink_notifier:
1010         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1011         return status;
1012 }
1013
1014 static void __exit nfnetlink_log_fini(void)
1015 {
1016         nf_log_unregister(&nfulnl_logger);
1017 #ifdef CONFIG_PROC_FS
1018         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1019 #endif
1020         nfnetlink_subsys_unregister(&nfulnl_subsys);
1021         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1022 }
1023
1024 MODULE_DESCRIPTION("netfilter userspace logging");
1025 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1026 MODULE_LICENSE("GPL");
1027 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1028
1029 module_init(nfnetlink_log_init);
1030 module_exit(nfnetlink_log_fini);