[NETFILTER]: nfnetlink_log: fix style
[linux-2.6.git] / net / netfilter / nfnetlink_log.c
1 /*
2  * This is a module which is used for logging packets to userspace via
3  * nfetlink.
4  *
5  * (C) 2005 by Harald Welte <laforge@netfilter.org>
6  *
7  * Based on the old ipv4-only ipt_ULOG.c:
8  * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/init.h>
17 #include <linux/ip.h>
18 #include <linux/ipv6.h>
19 #include <linux/netdevice.h>
20 #include <linux/netfilter.h>
21 #include <linux/netlink.h>
22 #include <linux/netfilter/nfnetlink.h>
23 #include <linux/netfilter/nfnetlink_log.h>
24 #include <linux/spinlock.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/list.h>
29 #include <linux/jhash.h>
30 #include <linux/random.h>
31 #include <net/sock.h>
32
33 #include <asm/atomic.h>
34
35 #ifdef CONFIG_BRIDGE_NETFILTER
36 #include "../bridge/br_private.h"
37 #endif
38
39 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
40 #define NFULNL_TIMEOUT_DEFAULT  100     /* every second */
41 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
42
43 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
44                                      printk(x, ## args); } while (0);
45
46 #if 0
47 #define UDEBUG(x, args ...)     printk(KERN_DEBUG "%s(%d):%s(): " x,       \
48                                         __FILE__, __LINE__, __FUNCTION__,  \
49                                         ## args)
50 #else
51 #define UDEBUG(x, ...)
52 #endif
53
54 struct nfulnl_instance {
55         struct hlist_node hlist;        /* global list of instances */
56         spinlock_t lock;
57         atomic_t use;                   /* use count */
58
59         unsigned int qlen;              /* number of nlmsgs in skb */
60         struct sk_buff *skb;            /* pre-allocatd skb */
61         struct timer_list timer;
62         int peer_pid;                   /* PID of the peer process */
63
64         /* configurable parameters */
65         unsigned int flushtimeout;      /* timeout until queue flush */
66         unsigned int nlbufsiz;          /* netlink buffer allocation size */
67         unsigned int qthreshold;        /* threshold of the queue */
68         u_int32_t copy_range;
69         u_int32_t seq;                  /* instance-local sequential counter */
70         u_int16_t group_num;            /* number of this queue */
71         u_int16_t flags;
72         u_int8_t copy_mode;
73 };
74
75 static DEFINE_RWLOCK(instances_lock);
76 static atomic_t global_seq;
77
78 #define INSTANCE_BUCKETS        16
79 static struct hlist_head instance_table[INSTANCE_BUCKETS];
80 static unsigned int hash_init;
81
82 static inline u_int8_t instance_hashfn(u_int16_t group_num)
83 {
84         return ((group_num & 0xff) % INSTANCE_BUCKETS);
85 }
86
87 static struct nfulnl_instance *
88 __instance_lookup(u_int16_t group_num)
89 {
90         struct hlist_head *head;
91         struct hlist_node *pos;
92         struct nfulnl_instance *inst;
93
94         UDEBUG("entering (group_num=%u)\n", group_num);
95
96         head = &instance_table[instance_hashfn(group_num)];
97         hlist_for_each_entry(inst, pos, head, hlist) {
98                 if (inst->group_num == group_num)
99                         return inst;
100         }
101         return NULL;
102 }
103
104 static inline void
105 instance_get(struct nfulnl_instance *inst)
106 {
107         atomic_inc(&inst->use);
108 }
109
110 static struct nfulnl_instance *
111 instance_lookup_get(u_int16_t group_num)
112 {
113         struct nfulnl_instance *inst;
114
115         read_lock_bh(&instances_lock);
116         inst = __instance_lookup(group_num);
117         if (inst)
118                 instance_get(inst);
119         read_unlock_bh(&instances_lock);
120
121         return inst;
122 }
123
124 static void
125 instance_put(struct nfulnl_instance *inst)
126 {
127         if (inst && atomic_dec_and_test(&inst->use)) {
128                 UDEBUG("kfree(inst=%p)\n", inst);
129                 kfree(inst);
130                 module_put(THIS_MODULE);
131         }
132 }
133
134 static void nfulnl_timer(unsigned long data);
135
136 static struct nfulnl_instance *
137 instance_create(u_int16_t group_num, int pid)
138 {
139         struct nfulnl_instance *inst;
140
141         UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
142                 pid);
143
144         write_lock_bh(&instances_lock);
145         if (__instance_lookup(group_num)) {
146                 inst = NULL;
147                 UDEBUG("aborting, instance already exists\n");
148                 goto out_unlock;
149         }
150
151         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
152         if (!inst)
153                 goto out_unlock;
154
155         INIT_HLIST_NODE(&inst->hlist);
156         spin_lock_init(&inst->lock);
157         /* needs to be two, since we _put() after creation */
158         atomic_set(&inst->use, 2);
159
160         setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
161
162         inst->peer_pid = pid;
163         inst->group_num = group_num;
164
165         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
166         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
167         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
168         inst->copy_mode         = NFULNL_COPY_PACKET;
169         inst->copy_range        = 0xffff;
170
171         if (!try_module_get(THIS_MODULE))
172                 goto out_free;
173
174         hlist_add_head(&inst->hlist,
175                        &instance_table[instance_hashfn(group_num)]);
176
177         UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
178                 inst->hlist.next);
179
180         write_unlock_bh(&instances_lock);
181
182         return inst;
183
184 out_free:
185         instance_put(inst);
186 out_unlock:
187         write_unlock_bh(&instances_lock);
188         return NULL;
189 }
190
191 static void __nfulnl_flush(struct nfulnl_instance *inst);
192
193 static void
194 __instance_destroy(struct nfulnl_instance *inst)
195 {
196         /* first pull it out of the global list */
197         UDEBUG("removing instance %p (queuenum=%u) from hash\n",
198                 inst, inst->group_num);
199
200         hlist_del(&inst->hlist);
201
202         /* then flush all pending packets from skb */
203
204         spin_lock_bh(&inst->lock);
205         if (inst->skb)
206                 __nfulnl_flush(inst);
207         spin_unlock_bh(&inst->lock);
208
209         /* and finally put the refcount */
210         instance_put(inst);
211 }
212
213 static inline void
214 instance_destroy(struct nfulnl_instance *inst)
215 {
216         write_lock_bh(&instances_lock);
217         __instance_destroy(inst);
218         write_unlock_bh(&instances_lock);
219 }
220
221 static int
222 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
223                   unsigned int range)
224 {
225         int status = 0;
226
227         spin_lock_bh(&inst->lock);
228
229         switch (mode) {
230         case NFULNL_COPY_NONE:
231         case NFULNL_COPY_META:
232                 inst->copy_mode = mode;
233                 inst->copy_range = 0;
234                 break;
235
236         case NFULNL_COPY_PACKET:
237                 inst->copy_mode = mode;
238                 /* we're using struct nlattr which has 16bit nfa_len */
239                 if (range > 0xffff)
240                         inst->copy_range = 0xffff;
241                 else
242                         inst->copy_range = range;
243                 break;
244
245         default:
246                 status = -EINVAL;
247                 break;
248         }
249
250         spin_unlock_bh(&inst->lock);
251
252         return status;
253 }
254
255 static int
256 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
257 {
258         int status;
259
260         spin_lock_bh(&inst->lock);
261         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
262                 status = -ERANGE;
263         else if (nlbufsiz > 131072)
264                 status = -ERANGE;
265         else {
266                 inst->nlbufsiz = nlbufsiz;
267                 status = 0;
268         }
269         spin_unlock_bh(&inst->lock);
270
271         return status;
272 }
273
274 static int
275 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
276 {
277         spin_lock_bh(&inst->lock);
278         inst->flushtimeout = timeout;
279         spin_unlock_bh(&inst->lock);
280
281         return 0;
282 }
283
284 static int
285 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
286 {
287         spin_lock_bh(&inst->lock);
288         inst->qthreshold = qthresh;
289         spin_unlock_bh(&inst->lock);
290
291         return 0;
292 }
293
294 static int
295 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
296 {
297         spin_lock_bh(&inst->lock);
298         inst->flags = flags;
299         spin_unlock_bh(&inst->lock);
300
301         return 0;
302 }
303
304 static struct sk_buff *
305 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
306 {
307         struct sk_buff *skb;
308         unsigned int n;
309
310         UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
311
312         /* alloc skb which should be big enough for a whole multipart
313          * message.  WARNING: has to be <= 128k due to slab restrictions */
314
315         n = max(inst_size, pkt_size);
316         skb = alloc_skb(n, GFP_ATOMIC);
317         if (!skb) {
318                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
319                         inst_size);
320
321                 if (n > pkt_size) {
322                         /* try to allocate only as much as we need for current
323                          * packet */
324
325                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
326                         if (!skb)
327                                 PRINTR("nfnetlink_log: can't even alloc %u "
328                                        "bytes\n", pkt_size);
329                 }
330         }
331
332         return skb;
333 }
334
335 static int
336 __nfulnl_send(struct nfulnl_instance *inst)
337 {
338         int status = -1;
339
340         if (inst->qlen > 1)
341                 NLMSG_PUT(inst->skb, 0, 0,
342                           NLMSG_DONE,
343                           sizeof(struct nfgenmsg));
344
345         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
346         if (status < 0) {
347                 UDEBUG("netlink_unicast() failed\n");
348                 /* FIXME: statistics */
349         }
350
351         inst->qlen = 0;
352         inst->skb = NULL;
353
354 nlmsg_failure:
355         return status;
356 }
357
358 static void
359 __nfulnl_flush(struct nfulnl_instance *inst)
360 {
361         /* timer holds a reference */
362         if (del_timer(&inst->timer))
363                 instance_put(inst);
364         if (inst->skb)
365                 __nfulnl_send(inst);
366 }
367
368 static void
369 nfulnl_timer(unsigned long data)
370 {
371         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
372
373         UDEBUG("timer function called, flushing buffer\n");
374
375         spin_lock_bh(&inst->lock);
376         if (inst->skb)
377                 __nfulnl_send(inst);
378         spin_unlock_bh(&inst->lock);
379         instance_put(inst);
380 }
381
382 /* This is an inline function, we don't really care about a long
383  * list of arguments */
384 static inline int
385 __build_packet_message(struct nfulnl_instance *inst,
386                         const struct sk_buff *skb,
387                         unsigned int data_len,
388                         unsigned int pf,
389                         unsigned int hooknum,
390                         const struct net_device *indev,
391                         const struct net_device *outdev,
392                         const struct nf_loginfo *li,
393                         const char *prefix, unsigned int plen)
394 {
395         struct nfulnl_msg_packet_hdr pmsg;
396         struct nlmsghdr *nlh;
397         struct nfgenmsg *nfmsg;
398         __be32 tmp_uint;
399         sk_buff_data_t old_tail = inst->skb->tail;
400
401         UDEBUG("entered\n");
402
403         nlh = NLMSG_PUT(inst->skb, 0, 0,
404                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
405                         sizeof(struct nfgenmsg));
406         nfmsg = NLMSG_DATA(nlh);
407         nfmsg->nfgen_family = pf;
408         nfmsg->version = NFNETLINK_V0;
409         nfmsg->res_id = htons(inst->group_num);
410
411         pmsg.hw_protocol        = skb->protocol;
412         pmsg.hook               = hooknum;
413
414         NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
415
416         if (prefix)
417                 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
418
419         if (indev) {
420                 tmp_uint = htonl(indev->ifindex);
421 #ifndef CONFIG_BRIDGE_NETFILTER
422                 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
423                         &tmp_uint);
424 #else
425                 if (pf == PF_BRIDGE) {
426                         /* Case 1: outdev is physical input device, we need to
427                          * look for bridge group (when called from
428                          * netfilter_bridge) */
429                         NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
430                                 sizeof(tmp_uint), &tmp_uint);
431                         /* this is the bridge group "brX" */
432                         tmp_uint = htonl(indev->br_port->br->dev->ifindex);
433                         NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
434                                 sizeof(tmp_uint), &tmp_uint);
435                 } else {
436                         /* Case 2: indev is bridge group, we need to look for
437                          * physical device (when called from ipv4) */
438                         NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
439                                 sizeof(tmp_uint), &tmp_uint);
440                         if (skb->nf_bridge && skb->nf_bridge->physindev) {
441                                 tmp_uint =
442                                     htonl(skb->nf_bridge->physindev->ifindex);
443                                 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
444                                         sizeof(tmp_uint), &tmp_uint);
445                         }
446                 }
447 #endif
448         }
449
450         if (outdev) {
451                 tmp_uint = htonl(outdev->ifindex);
452 #ifndef CONFIG_BRIDGE_NETFILTER
453                 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
454                         &tmp_uint);
455 #else
456                 if (pf == PF_BRIDGE) {
457                         /* Case 1: outdev is physical output device, we need to
458                          * look for bridge group (when called from
459                          * netfilter_bridge) */
460                         NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
461                                 sizeof(tmp_uint), &tmp_uint);
462                         /* this is the bridge group "brX" */
463                         tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
464                         NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
465                                 sizeof(tmp_uint), &tmp_uint);
466                 } else {
467                         /* Case 2: indev is a bridge group, we need to look
468                          * for physical device (when called from ipv4) */
469                         NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
470                                 sizeof(tmp_uint), &tmp_uint);
471                         if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
472                                 tmp_uint =
473                                     htonl(skb->nf_bridge->physoutdev->ifindex);
474                                 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
475                                         sizeof(tmp_uint), &tmp_uint);
476                         }
477                 }
478 #endif
479         }
480
481         if (skb->mark) {
482                 tmp_uint = htonl(skb->mark);
483                 NLA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
484         }
485
486         if (indev && skb->dev) {
487                 struct nfulnl_msg_packet_hw phw;
488                 int len = dev_parse_header(skb, phw.hw_addr);
489                 if (len > 0) {
490                         phw.hw_addrlen = htons(len);
491                         NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
492                 }
493         }
494
495         if (skb->tstamp.tv64) {
496                 struct nfulnl_msg_packet_timestamp ts;
497                 struct timeval tv = ktime_to_timeval(skb->tstamp);
498                 ts.sec = cpu_to_be64(tv.tv_sec);
499                 ts.usec = cpu_to_be64(tv.tv_usec);
500
501                 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
502         }
503
504         /* UID */
505         if (skb->sk) {
506                 read_lock_bh(&skb->sk->sk_callback_lock);
507                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
508                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
509                         /* need to unlock here since NLA_PUT may goto */
510                         read_unlock_bh(&skb->sk->sk_callback_lock);
511                         NLA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
512                 } else
513                         read_unlock_bh(&skb->sk->sk_callback_lock);
514         }
515
516         /* local sequence number */
517         if (inst->flags & NFULNL_CFG_F_SEQ) {
518                 tmp_uint = htonl(inst->seq++);
519                 NLA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
520         }
521         /* global sequence number */
522         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
523                 tmp_uint = htonl(atomic_inc_return(&global_seq));
524                 NLA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
525         }
526
527         if (data_len) {
528                 struct nlattr *nla;
529                 int size = nla_attr_size(data_len);
530
531                 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
532                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
533                         goto nlmsg_failure;
534                 }
535
536                 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
537                 nla->nla_type = NFULA_PAYLOAD;
538                 nla->nla_len = size;
539
540                 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
541                         BUG();
542         }
543
544         nlh->nlmsg_len = inst->skb->tail - old_tail;
545         return 0;
546
547 nlmsg_failure:
548         UDEBUG("nlmsg_failure\n");
549 nla_put_failure:
550         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
551         return -1;
552 }
553
554 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
555
556 static struct nf_loginfo default_loginfo = {
557         .type =         NF_LOG_TYPE_ULOG,
558         .u = {
559                 .ulog = {
560                         .copy_len       = 0xffff,
561                         .group          = 0,
562                         .qthreshold     = 1,
563                 },
564         },
565 };
566
567 /* log handler for internal netfilter logging api */
568 static void
569 nfulnl_log_packet(unsigned int pf,
570                   unsigned int hooknum,
571                   const struct sk_buff *skb,
572                   const struct net_device *in,
573                   const struct net_device *out,
574                   const struct nf_loginfo *li_user,
575                   const char *prefix)
576 {
577         unsigned int size, data_len;
578         struct nfulnl_instance *inst;
579         const struct nf_loginfo *li;
580         unsigned int qthreshold;
581         unsigned int plen;
582
583         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
584                 li = li_user;
585         else
586                 li = &default_loginfo;
587
588         inst = instance_lookup_get(li->u.ulog.group);
589         if (!inst)
590                 return;
591
592         plen = 0;
593         if (prefix)
594                 plen = strlen(prefix) + 1;
595
596         /* FIXME: do we want to make the size calculation conditional based on
597          * what is actually present?  way more branches and checks, but more
598          * memory efficient... */
599         size =    NLMSG_ALIGN(sizeof(struct nfgenmsg))
600                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
601                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
602                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
603 #ifdef CONFIG_BRIDGE_NETFILTER
604                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
605                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
606 #endif
607                 + nla_total_size(sizeof(u_int32_t))     /* mark */
608                 + nla_total_size(sizeof(u_int32_t))     /* uid */
609                 + nla_total_size(plen)                  /* prefix */
610                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
611                 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
612
613         UDEBUG("initial size=%u\n", size);
614
615         spin_lock_bh(&inst->lock);
616
617         if (inst->flags & NFULNL_CFG_F_SEQ)
618                 size += nla_total_size(sizeof(u_int32_t));
619         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
620                 size += nla_total_size(sizeof(u_int32_t));
621
622         qthreshold = inst->qthreshold;
623         /* per-rule qthreshold overrides per-instance */
624         if (qthreshold > li->u.ulog.qthreshold)
625                 qthreshold = li->u.ulog.qthreshold;
626
627         switch (inst->copy_mode) {
628         case NFULNL_COPY_META:
629         case NFULNL_COPY_NONE:
630                 data_len = 0;
631                 break;
632
633         case NFULNL_COPY_PACKET:
634                 if (inst->copy_range == 0
635                     || inst->copy_range > skb->len)
636                         data_len = skb->len;
637                 else
638                         data_len = inst->copy_range;
639
640                 size += nla_total_size(data_len);
641                 UDEBUG("copy_packet, therefore size now %u\n", size);
642                 break;
643
644         default:
645                 goto unlock_and_release;
646         }
647
648         if (inst->skb &&
649             size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
650                 /* either the queue len is too high or we don't have
651                  * enough room in the skb left. flush to userspace. */
652                 UDEBUG("flushing old skb\n");
653
654                 __nfulnl_flush(inst);
655         }
656
657         if (!inst->skb) {
658                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
659                 if (!inst->skb)
660                         goto alloc_failure;
661         }
662
663         UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
664         inst->qlen++;
665
666         __build_packet_message(inst, skb, data_len, pf,
667                                 hooknum, in, out, li, prefix, plen);
668
669         if (inst->qlen >= qthreshold)
670                 __nfulnl_flush(inst);
671         /* timer_pending always called within inst->lock, so there
672          * is no chance of a race here */
673         else if (!timer_pending(&inst->timer)) {
674                 instance_get(inst);
675                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
676                 add_timer(&inst->timer);
677         }
678
679 unlock_and_release:
680         spin_unlock_bh(&inst->lock);
681         instance_put(inst);
682         return;
683
684 alloc_failure:
685         UDEBUG("error allocating skb\n");
686         /* FIXME: statistics */
687         goto unlock_and_release;
688 }
689
690 static int
691 nfulnl_rcv_nl_event(struct notifier_block *this,
692                    unsigned long event, void *ptr)
693 {
694         struct netlink_notify *n = ptr;
695
696         if (event == NETLINK_URELEASE &&
697             n->protocol == NETLINK_NETFILTER && n->pid) {
698                 int i;
699
700                 /* destroy all instances for this pid */
701                 write_lock_bh(&instances_lock);
702                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
703                         struct hlist_node *tmp, *t2;
704                         struct nfulnl_instance *inst;
705                         struct hlist_head *head = &instance_table[i];
706
707                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
708                                 UDEBUG("node = %p\n", inst);
709                                 if ((n->net == &init_net) &&
710                                     (n->pid == inst->peer_pid))
711                                         __instance_destroy(inst);
712                         }
713                 }
714                 write_unlock_bh(&instances_lock);
715         }
716         return NOTIFY_DONE;
717 }
718
719 static struct notifier_block nfulnl_rtnl_notifier = {
720         .notifier_call  = nfulnl_rcv_nl_event,
721 };
722
723 static int
724 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
725                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
726 {
727         return -ENOTSUPP;
728 }
729
730 static struct nf_logger nfulnl_logger = {
731         .name   = "nfnetlink_log",
732         .logfn  = &nfulnl_log_packet,
733         .me     = THIS_MODULE,
734 };
735
736 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
737         [NFULA_CFG_CMD]         = { .len = sizeof(struct nfulnl_msg_config_cmd) },
738         [NFULA_CFG_MODE]        = { .len = sizeof(struct nfulnl_msg_config_mode) },
739         [NFULA_CFG_TIMEOUT]     = { .type = NLA_U32 },
740         [NFULA_CFG_QTHRESH]     = { .type = NLA_U32 },
741         [NFULA_CFG_NLBUFSIZ]    = { .type = NLA_U32 },
742         [NFULA_CFG_FLAGS]       = { .type = NLA_U16 },
743 };
744
745 static int
746 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
747                    struct nlmsghdr *nlh, struct nlattr *nfula[])
748 {
749         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
750         u_int16_t group_num = ntohs(nfmsg->res_id);
751         struct nfulnl_instance *inst;
752         int ret = 0;
753
754         UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
755
756         inst = instance_lookup_get(group_num);
757         if (nfula[NFULA_CFG_CMD]) {
758                 u_int8_t pf = nfmsg->nfgen_family;
759                 struct nfulnl_msg_config_cmd *cmd;
760                 cmd = nla_data(nfula[NFULA_CFG_CMD]);
761                 UDEBUG("found CFG_CMD for\n");
762
763                 switch (cmd->command) {
764                 case NFULNL_CFG_CMD_BIND:
765                         if (inst) {
766                                 ret = -EBUSY;
767                                 goto out_put;
768                         }
769
770                         inst = instance_create(group_num,
771                                                NETLINK_CB(skb).pid);
772                         if (!inst) {
773                                 ret = -EINVAL;
774                                 goto out;
775                         }
776                         break;
777                 case NFULNL_CFG_CMD_UNBIND:
778                         if (!inst) {
779                                 ret = -ENODEV;
780                                 goto out;
781                         }
782
783                         if (inst->peer_pid != NETLINK_CB(skb).pid) {
784                                 ret = -EPERM;
785                                 goto out_put;
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 = -EINVAL;
802                         break;
803                 }
804
805                 if (!inst)
806                         goto out;
807         } else {
808                 if (!inst) {
809                         UDEBUG("no config command, and no instance for "
810                                 "group=%u pid=%u =>ENOENT\n",
811                                 group_num, NETLINK_CB(skb).pid);
812                         ret = -ENOENT;
813                         goto out;
814                 }
815
816                 if (inst->peer_pid != NETLINK_CB(skb).pid) {
817                         UDEBUG("no config command, and wrong pid\n");
818                         ret = -EPERM;
819                         goto out_put;
820                 }
821         }
822
823         if (nfula[NFULA_CFG_MODE]) {
824                 struct nfulnl_msg_config_mode *params;
825                 params = nla_data(nfula[NFULA_CFG_MODE]);
826
827                 nfulnl_set_mode(inst, params->copy_mode,
828                                 ntohl(params->copy_range));
829         }
830
831         if (nfula[NFULA_CFG_TIMEOUT]) {
832                 __be32 timeout =
833                         *(__be32 *)nla_data(nfula[NFULA_CFG_TIMEOUT]);
834
835                 nfulnl_set_timeout(inst, ntohl(timeout));
836         }
837
838         if (nfula[NFULA_CFG_NLBUFSIZ]) {
839                 __be32 nlbufsiz =
840                         *(__be32 *)nla_data(nfula[NFULA_CFG_NLBUFSIZ]);
841
842                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
843         }
844
845         if (nfula[NFULA_CFG_QTHRESH]) {
846                 __be32 qthresh =
847                         *(__be32 *)nla_data(nfula[NFULA_CFG_QTHRESH]);
848
849                 nfulnl_set_qthresh(inst, ntohl(qthresh));
850         }
851
852         if (nfula[NFULA_CFG_FLAGS]) {
853                 __be16 flags =
854                         *(__be16 *)nla_data(nfula[NFULA_CFG_FLAGS]);
855                 nfulnl_set_flags(inst, ntohs(flags));
856         }
857
858 out_put:
859         instance_put(inst);
860 out:
861         return ret;
862 }
863
864 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
865         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
866                                     .attr_count = NFULA_MAX, },
867         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
868                                     .attr_count = NFULA_CFG_MAX,
869                                     .policy = nfula_cfg_policy },
870 };
871
872 static const struct nfnetlink_subsystem nfulnl_subsys = {
873         .name           = "log",
874         .subsys_id      = NFNL_SUBSYS_ULOG,
875         .cb_count       = NFULNL_MSG_MAX,
876         .cb             = nfulnl_cb,
877 };
878
879 #ifdef CONFIG_PROC_FS
880 struct iter_state {
881         unsigned int bucket;
882 };
883
884 static struct hlist_node *get_first(struct iter_state *st)
885 {
886         if (!st)
887                 return NULL;
888
889         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
890                 if (!hlist_empty(&instance_table[st->bucket]))
891                         return instance_table[st->bucket].first;
892         }
893         return NULL;
894 }
895
896 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
897 {
898         h = h->next;
899         while (!h) {
900                 if (++st->bucket >= INSTANCE_BUCKETS)
901                         return NULL;
902
903                 h = instance_table[st->bucket].first;
904         }
905         return h;
906 }
907
908 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
909 {
910         struct hlist_node *head;
911         head = get_first(st);
912
913         if (head)
914                 while (pos && (head = get_next(st, head)))
915                         pos--;
916         return pos ? NULL : head;
917 }
918
919 static void *seq_start(struct seq_file *seq, loff_t *pos)
920 {
921         read_lock_bh(&instances_lock);
922         return get_idx(seq->private, *pos);
923 }
924
925 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
926 {
927         (*pos)++;
928         return get_next(s->private, v);
929 }
930
931 static void seq_stop(struct seq_file *s, void *v)
932 {
933         read_unlock_bh(&instances_lock);
934 }
935
936 static int seq_show(struct seq_file *s, void *v)
937 {
938         const struct nfulnl_instance *inst = v;
939
940         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
941                           inst->group_num,
942                           inst->peer_pid, inst->qlen,
943                           inst->copy_mode, inst->copy_range,
944                           inst->flushtimeout, atomic_read(&inst->use));
945 }
946
947 static const struct seq_operations nful_seq_ops = {
948         .start  = seq_start,
949         .next   = seq_next,
950         .stop   = seq_stop,
951         .show   = seq_show,
952 };
953
954 static int nful_open(struct inode *inode, struct file *file)
955 {
956         struct seq_file *seq;
957         struct iter_state *is;
958         int ret;
959
960         is = kzalloc(sizeof(*is), GFP_KERNEL);
961         if (!is)
962                 return -ENOMEM;
963         ret = seq_open(file, &nful_seq_ops);
964         if (ret < 0)
965                 goto out_free;
966         seq = file->private_data;
967         seq->private = is;
968         return ret;
969 out_free:
970         kfree(is);
971         return ret;
972 }
973
974 static const struct file_operations nful_file_ops = {
975         .owner   = THIS_MODULE,
976         .open    = nful_open,
977         .read    = seq_read,
978         .llseek  = seq_lseek,
979         .release = seq_release_private,
980 };
981
982 #endif /* PROC_FS */
983
984 static int __init nfnetlink_log_init(void)
985 {
986         int i, status = -ENOMEM;
987 #ifdef CONFIG_PROC_FS
988         struct proc_dir_entry *proc_nful;
989 #endif
990
991         for (i = 0; i < INSTANCE_BUCKETS; i++)
992                 INIT_HLIST_HEAD(&instance_table[i]);
993
994         /* it's not really all that important to have a random value, so
995          * we can do this from the init function, even if there hasn't
996          * been that much entropy yet */
997         get_random_bytes(&hash_init, sizeof(hash_init));
998
999         netlink_register_notifier(&nfulnl_rtnl_notifier);
1000         status = nfnetlink_subsys_register(&nfulnl_subsys);
1001         if (status < 0) {
1002                 printk(KERN_ERR "log: failed to create netlink socket\n");
1003                 goto cleanup_netlink_notifier;
1004         }
1005
1006 #ifdef CONFIG_PROC_FS
1007         proc_nful = create_proc_entry("nfnetlink_log", 0440,
1008                                       proc_net_netfilter);
1009         if (!proc_nful)
1010                 goto cleanup_subsys;
1011         proc_nful->proc_fops = &nful_file_ops;
1012 #endif
1013         return status;
1014
1015 #ifdef CONFIG_PROC_FS
1016 cleanup_subsys:
1017         nfnetlink_subsys_unregister(&nfulnl_subsys);
1018 #endif
1019 cleanup_netlink_notifier:
1020         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1021         return status;
1022 }
1023
1024 static void __exit nfnetlink_log_fini(void)
1025 {
1026         nf_log_unregister(&nfulnl_logger);
1027 #ifdef CONFIG_PROC_FS
1028         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1029 #endif
1030         nfnetlink_subsys_unregister(&nfulnl_subsys);
1031         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1032 }
1033
1034 MODULE_DESCRIPTION("netfilter userspace logging");
1035 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1036 MODULE_LICENSE("GPL");
1037 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1038
1039 module_init(nfnetlink_log_init);
1040 module_exit(nfnetlink_log_fini);