netfilter: nfnetlink_log: fix warning and prototype mismatch
[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 #include <net/netfilter/nfnetlink_log.h>
34
35 #include <asm/atomic.h>
36
37 #ifdef CONFIG_BRIDGE_NETFILTER
38 #include "../bridge/br_private.h"
39 #endif
40
41 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
42 #define NFULNL_TIMEOUT_DEFAULT  HZ      /* every second */
43 #define NFULNL_QTHRESH_DEFAULT  100     /* 100 packets */
44 #define NFULNL_COPY_RANGE_MAX   0xFFFF  /* max packet size is limited by 16-bit struct nfattr nfa_len field */
45
46 #define PRINTR(x, args...)      do { if (net_ratelimit()) \
47                                      printk(x, ## args); } while (0);
48
49 struct nfulnl_instance {
50         struct hlist_node hlist;        /* global list of instances */
51         spinlock_t lock;
52         atomic_t use;                   /* use count */
53
54         unsigned int qlen;              /* number of nlmsgs in skb */
55         struct sk_buff *skb;            /* pre-allocatd skb */
56         struct timer_list timer;
57         int peer_pid;                   /* PID of the peer process */
58
59         /* configurable parameters */
60         unsigned int flushtimeout;      /* timeout until queue flush */
61         unsigned int nlbufsiz;          /* netlink buffer allocation size */
62         unsigned int qthreshold;        /* threshold of the queue */
63         u_int32_t copy_range;
64         u_int32_t seq;                  /* instance-local sequential counter */
65         u_int16_t group_num;            /* number of this queue */
66         u_int16_t flags;
67         u_int8_t copy_mode;
68 };
69
70 static DEFINE_RWLOCK(instances_lock);
71 static atomic_t global_seq;
72
73 #define INSTANCE_BUCKETS        16
74 static struct hlist_head instance_table[INSTANCE_BUCKETS];
75 static unsigned int hash_init;
76
77 static inline u_int8_t instance_hashfn(u_int16_t group_num)
78 {
79         return ((group_num & 0xff) % INSTANCE_BUCKETS);
80 }
81
82 static struct nfulnl_instance *
83 __instance_lookup(u_int16_t group_num)
84 {
85         struct hlist_head *head;
86         struct hlist_node *pos;
87         struct nfulnl_instance *inst;
88
89         head = &instance_table[instance_hashfn(group_num)];
90         hlist_for_each_entry(inst, pos, head, hlist) {
91                 if (inst->group_num == group_num)
92                         return inst;
93         }
94         return NULL;
95 }
96
97 static inline void
98 instance_get(struct nfulnl_instance *inst)
99 {
100         atomic_inc(&inst->use);
101 }
102
103 static struct nfulnl_instance *
104 instance_lookup_get(u_int16_t group_num)
105 {
106         struct nfulnl_instance *inst;
107
108         read_lock_bh(&instances_lock);
109         inst = __instance_lookup(group_num);
110         if (inst)
111                 instance_get(inst);
112         read_unlock_bh(&instances_lock);
113
114         return inst;
115 }
116
117 static void
118 instance_put(struct nfulnl_instance *inst)
119 {
120         if (inst && atomic_dec_and_test(&inst->use)) {
121                 kfree(inst);
122                 module_put(THIS_MODULE);
123         }
124 }
125
126 static void nfulnl_timer(unsigned long data);
127
128 static struct nfulnl_instance *
129 instance_create(u_int16_t group_num, int pid)
130 {
131         struct nfulnl_instance *inst;
132         int err;
133
134         write_lock_bh(&instances_lock);
135         if (__instance_lookup(group_num)) {
136                 err = -EEXIST;
137                 goto out_unlock;
138         }
139
140         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
141         if (!inst) {
142                 err = -ENOMEM;
143                 goto out_unlock;
144         }
145
146         if (!try_module_get(THIS_MODULE)) {
147                 kfree(inst);
148                 err = -EAGAIN;
149                 goto out_unlock;
150         }
151
152         INIT_HLIST_NODE(&inst->hlist);
153         spin_lock_init(&inst->lock);
154         /* needs to be two, since we _put() after creation */
155         atomic_set(&inst->use, 2);
156
157         setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
158
159         inst->peer_pid = pid;
160         inst->group_num = group_num;
161
162         inst->qthreshold        = NFULNL_QTHRESH_DEFAULT;
163         inst->flushtimeout      = NFULNL_TIMEOUT_DEFAULT;
164         inst->nlbufsiz          = NFULNL_NLBUFSIZ_DEFAULT;
165         inst->copy_mode         = NFULNL_COPY_PACKET;
166         inst->copy_range        = NFULNL_COPY_RANGE_MAX;
167
168         hlist_add_head(&inst->hlist,
169                        &instance_table[instance_hashfn(group_num)]);
170
171         write_unlock_bh(&instances_lock);
172
173         return inst;
174
175 out_unlock:
176         write_unlock_bh(&instances_lock);
177         return ERR_PTR(err);
178 }
179
180 static void __nfulnl_flush(struct nfulnl_instance *inst);
181
182 static void
183 __instance_destroy(struct nfulnl_instance *inst)
184 {
185         /* first pull it out of the global list */
186         hlist_del(&inst->hlist);
187
188         /* then flush all pending packets from skb */
189
190         spin_lock_bh(&inst->lock);
191         if (inst->skb)
192                 __nfulnl_flush(inst);
193         spin_unlock_bh(&inst->lock);
194
195         /* and finally put the refcount */
196         instance_put(inst);
197 }
198
199 static inline void
200 instance_destroy(struct nfulnl_instance *inst)
201 {
202         write_lock_bh(&instances_lock);
203         __instance_destroy(inst);
204         write_unlock_bh(&instances_lock);
205 }
206
207 static int
208 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
209                   unsigned int range)
210 {
211         int status = 0;
212
213         spin_lock_bh(&inst->lock);
214
215         switch (mode) {
216         case NFULNL_COPY_NONE:
217         case NFULNL_COPY_META:
218                 inst->copy_mode = mode;
219                 inst->copy_range = 0;
220                 break;
221
222         case NFULNL_COPY_PACKET:
223                 inst->copy_mode = mode;
224                 inst->copy_range = min_t(unsigned int,
225                                          range, NFULNL_COPY_RANGE_MAX);
226                 break;
227
228         default:
229                 status = -EINVAL;
230                 break;
231         }
232
233         spin_unlock_bh(&inst->lock);
234
235         return status;
236 }
237
238 static int
239 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
240 {
241         int status;
242
243         spin_lock_bh(&inst->lock);
244         if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
245                 status = -ERANGE;
246         else if (nlbufsiz > 131072)
247                 status = -ERANGE;
248         else {
249                 inst->nlbufsiz = nlbufsiz;
250                 status = 0;
251         }
252         spin_unlock_bh(&inst->lock);
253
254         return status;
255 }
256
257 static int
258 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
259 {
260         spin_lock_bh(&inst->lock);
261         inst->flushtimeout = timeout;
262         spin_unlock_bh(&inst->lock);
263
264         return 0;
265 }
266
267 static int
268 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
269 {
270         spin_lock_bh(&inst->lock);
271         inst->qthreshold = qthresh;
272         spin_unlock_bh(&inst->lock);
273
274         return 0;
275 }
276
277 static int
278 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
279 {
280         spin_lock_bh(&inst->lock);
281         inst->flags = flags;
282         spin_unlock_bh(&inst->lock);
283
284         return 0;
285 }
286
287 static struct sk_buff *
288 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
289 {
290         struct sk_buff *skb;
291         unsigned int n;
292
293         /* alloc skb which should be big enough for a whole multipart
294          * message.  WARNING: has to be <= 128k due to slab restrictions */
295
296         n = max(inst_size, pkt_size);
297         skb = alloc_skb(n, GFP_ATOMIC);
298         if (!skb) {
299                 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
300                         inst_size);
301
302                 if (n > pkt_size) {
303                         /* try to allocate only as much as we need for current
304                          * packet */
305
306                         skb = alloc_skb(pkt_size, GFP_ATOMIC);
307                         if (!skb)
308                                 PRINTR("nfnetlink_log: can't even alloc %u "
309                                        "bytes\n", pkt_size);
310                 }
311         }
312
313         return skb;
314 }
315
316 static int
317 __nfulnl_send(struct nfulnl_instance *inst)
318 {
319         int status = -1;
320
321         if (inst->qlen > 1)
322                 NLMSG_PUT(inst->skb, 0, 0,
323                           NLMSG_DONE,
324                           sizeof(struct nfgenmsg));
325
326         status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
327
328         inst->qlen = 0;
329         inst->skb = NULL;
330
331 nlmsg_failure:
332         return status;
333 }
334
335 static void
336 __nfulnl_flush(struct nfulnl_instance *inst)
337 {
338         /* timer holds a reference */
339         if (del_timer(&inst->timer))
340                 instance_put(inst);
341         if (inst->skb)
342                 __nfulnl_send(inst);
343 }
344
345 static void
346 nfulnl_timer(unsigned long data)
347 {
348         struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
349
350         spin_lock_bh(&inst->lock);
351         if (inst->skb)
352                 __nfulnl_send(inst);
353         spin_unlock_bh(&inst->lock);
354         instance_put(inst);
355 }
356
357 /* This is an inline function, we don't really care about a long
358  * list of arguments */
359 static inline int
360 __build_packet_message(struct nfulnl_instance *inst,
361                         const struct sk_buff *skb,
362                         unsigned int data_len,
363                         u_int8_t pf,
364                         unsigned int hooknum,
365                         const struct net_device *indev,
366                         const struct net_device *outdev,
367                         const struct nf_loginfo *li,
368                         const char *prefix, unsigned int plen)
369 {
370         struct nfulnl_msg_packet_hdr pmsg;
371         struct nlmsghdr *nlh;
372         struct nfgenmsg *nfmsg;
373         __be32 tmp_uint;
374         sk_buff_data_t old_tail = inst->skb->tail;
375
376         nlh = NLMSG_PUT(inst->skb, 0, 0,
377                         NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
378                         sizeof(struct nfgenmsg));
379         nfmsg = NLMSG_DATA(nlh);
380         nfmsg->nfgen_family = pf;
381         nfmsg->version = NFNETLINK_V0;
382         nfmsg->res_id = htons(inst->group_num);
383
384         pmsg.hw_protocol        = skb->protocol;
385         pmsg.hook               = hooknum;
386
387         NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
388
389         if (prefix)
390                 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
391
392         if (indev) {
393 #ifndef CONFIG_BRIDGE_NETFILTER
394                 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
395                              htonl(indev->ifindex));
396 #else
397                 if (pf == PF_BRIDGE) {
398                         /* Case 1: outdev is physical input device, we need to
399                          * look for bridge group (when called from
400                          * netfilter_bridge) */
401                         NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
402                                      htonl(indev->ifindex));
403                         /* this is the bridge group "brX" */
404                         NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
405                                      htonl(indev->br_port->br->dev->ifindex));
406                 } else {
407                         /* Case 2: indev is bridge group, we need to look for
408                          * physical device (when called from ipv4) */
409                         NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
410                                      htonl(indev->ifindex));
411                         if (skb->nf_bridge && skb->nf_bridge->physindev)
412                                 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
413                                              htonl(skb->nf_bridge->physindev->ifindex));
414                 }
415 #endif
416         }
417
418         if (outdev) {
419                 tmp_uint = htonl(outdev->ifindex);
420 #ifndef CONFIG_BRIDGE_NETFILTER
421                 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
422                              htonl(outdev->ifindex));
423 #else
424                 if (pf == PF_BRIDGE) {
425                         /* Case 1: outdev is physical output device, we need to
426                          * look for bridge group (when called from
427                          * netfilter_bridge) */
428                         NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
429                                      htonl(outdev->ifindex));
430                         /* this is the bridge group "brX" */
431                         NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
432                                      htonl(outdev->br_port->br->dev->ifindex));
433                 } else {
434                         /* Case 2: indev is a bridge group, we need to look
435                          * for physical device (when called from ipv4) */
436                         NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
437                                      htonl(outdev->ifindex));
438                         if (skb->nf_bridge && skb->nf_bridge->physoutdev)
439                                 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
440                                              htonl(skb->nf_bridge->physoutdev->ifindex));
441                 }
442 #endif
443         }
444
445         if (skb->mark)
446                 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
447
448         if (indev && skb->dev) {
449                 struct nfulnl_msg_packet_hw phw;
450                 int len = dev_parse_header(skb, phw.hw_addr);
451                 if (len > 0) {
452                         phw.hw_addrlen = htons(len);
453                         NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
454                 }
455         }
456
457         if (indev && skb_mac_header_was_set(skb)) {
458                 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
459                 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
460                              htons(skb->dev->hard_header_len));
461                 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
462                         skb_mac_header(skb));
463         }
464
465         if (skb->tstamp.tv64) {
466                 struct nfulnl_msg_packet_timestamp ts;
467                 struct timeval tv = ktime_to_timeval(skb->tstamp);
468                 ts.sec = cpu_to_be64(tv.tv_sec);
469                 ts.usec = cpu_to_be64(tv.tv_usec);
470
471                 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
472         }
473
474         /* UID */
475         if (skb->sk) {
476                 read_lock_bh(&skb->sk->sk_callback_lock);
477                 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
478                         __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
479                         __be32 gid = htonl(skb->sk->sk_socket->file->f_gid);
480                         /* need to unlock here since NLA_PUT may goto */
481                         read_unlock_bh(&skb->sk->sk_callback_lock);
482                         NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
483                         NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
484                 } else
485                         read_unlock_bh(&skb->sk->sk_callback_lock);
486         }
487
488         /* local sequence number */
489         if (inst->flags & NFULNL_CFG_F_SEQ)
490                 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
491
492         /* global sequence number */
493         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
494                 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
495                              htonl(atomic_inc_return(&global_seq)));
496
497         if (data_len) {
498                 struct nlattr *nla;
499                 int size = nla_attr_size(data_len);
500
501                 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
502                         printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
503                         goto nlmsg_failure;
504                 }
505
506                 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
507                 nla->nla_type = NFULA_PAYLOAD;
508                 nla->nla_len = size;
509
510                 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
511                         BUG();
512         }
513
514         nlh->nlmsg_len = inst->skb->tail - old_tail;
515         return 0;
516
517 nlmsg_failure:
518 nla_put_failure:
519         PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
520         return -1;
521 }
522
523 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
524
525 static struct nf_loginfo default_loginfo = {
526         .type =         NF_LOG_TYPE_ULOG,
527         .u = {
528                 .ulog = {
529                         .copy_len       = 0xffff,
530                         .group          = 0,
531                         .qthreshold     = 1,
532                 },
533         },
534 };
535
536 /* log handler for internal netfilter logging api */
537 void
538 nfulnl_log_packet(u_int8_t pf,
539                   unsigned int hooknum,
540                   const struct sk_buff *skb,
541                   const struct net_device *in,
542                   const struct net_device *out,
543                   const struct nf_loginfo *li_user,
544                   const char *prefix)
545 {
546         unsigned int size, data_len;
547         struct nfulnl_instance *inst;
548         const struct nf_loginfo *li;
549         unsigned int qthreshold;
550         unsigned int plen;
551
552         if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
553                 li = li_user;
554         else
555                 li = &default_loginfo;
556
557         inst = instance_lookup_get(li->u.ulog.group);
558         if (!inst)
559                 return;
560
561         plen = 0;
562         if (prefix)
563                 plen = strlen(prefix) + 1;
564
565         /* FIXME: do we want to make the size calculation conditional based on
566          * what is actually present?  way more branches and checks, but more
567          * memory efficient... */
568         size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
569                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
570                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
571                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
572 #ifdef CONFIG_BRIDGE_NETFILTER
573                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
574                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
575 #endif
576                 + nla_total_size(sizeof(u_int32_t))     /* mark */
577                 + nla_total_size(sizeof(u_int32_t))     /* uid */
578                 + nla_total_size(sizeof(u_int32_t))     /* gid */
579                 + nla_total_size(plen)                  /* prefix */
580                 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
581                 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
582
583         spin_lock_bh(&inst->lock);
584
585         if (inst->flags & NFULNL_CFG_F_SEQ)
586                 size += nla_total_size(sizeof(u_int32_t));
587         if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
588                 size += nla_total_size(sizeof(u_int32_t));
589
590         qthreshold = inst->qthreshold;
591         /* per-rule qthreshold overrides per-instance */
592         if (qthreshold > li->u.ulog.qthreshold)
593                 qthreshold = li->u.ulog.qthreshold;
594
595         switch (inst->copy_mode) {
596         case NFULNL_COPY_META:
597         case NFULNL_COPY_NONE:
598                 data_len = 0;
599                 break;
600
601         case NFULNL_COPY_PACKET:
602                 if (inst->copy_range == 0
603                     || inst->copy_range > skb->len)
604                         data_len = skb->len;
605                 else
606                         data_len = inst->copy_range;
607
608                 size += nla_total_size(data_len);
609                 break;
610
611         default:
612                 goto unlock_and_release;
613         }
614
615         if (inst->skb &&
616             size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
617                 /* either the queue len is too high or we don't have
618                  * enough room in the skb left. flush to userspace. */
619                 __nfulnl_flush(inst);
620         }
621
622         if (!inst->skb) {
623                 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
624                 if (!inst->skb)
625                         goto alloc_failure;
626         }
627
628         inst->qlen++;
629
630         __build_packet_message(inst, skb, data_len, pf,
631                                 hooknum, in, out, li, prefix, plen);
632
633         if (inst->qlen >= qthreshold)
634                 __nfulnl_flush(inst);
635         /* timer_pending always called within inst->lock, so there
636          * is no chance of a race here */
637         else if (!timer_pending(&inst->timer)) {
638                 instance_get(inst);
639                 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
640                 add_timer(&inst->timer);
641         }
642
643 unlock_and_release:
644         spin_unlock_bh(&inst->lock);
645         instance_put(inst);
646         return;
647
648 alloc_failure:
649         /* FIXME: statistics */
650         goto unlock_and_release;
651 }
652 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
653
654 static int
655 nfulnl_rcv_nl_event(struct notifier_block *this,
656                    unsigned long event, void *ptr)
657 {
658         struct netlink_notify *n = ptr;
659
660         if (event == NETLINK_URELEASE &&
661             n->protocol == NETLINK_NETFILTER && n->pid) {
662                 int i;
663
664                 /* destroy all instances for this pid */
665                 write_lock_bh(&instances_lock);
666                 for  (i = 0; i < INSTANCE_BUCKETS; i++) {
667                         struct hlist_node *tmp, *t2;
668                         struct nfulnl_instance *inst;
669                         struct hlist_head *head = &instance_table[i];
670
671                         hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
672                                 if ((n->net == &init_net) &&
673                                     (n->pid == inst->peer_pid))
674                                         __instance_destroy(inst);
675                         }
676                 }
677                 write_unlock_bh(&instances_lock);
678         }
679         return NOTIFY_DONE;
680 }
681
682 static struct notifier_block nfulnl_rtnl_notifier = {
683         .notifier_call  = nfulnl_rcv_nl_event,
684 };
685
686 static int
687 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
688                   struct nlmsghdr *nlh, struct nlattr *nfqa[])
689 {
690         return -ENOTSUPP;
691 }
692
693 static const struct nf_logger nfulnl_logger = {
694         .name   = "nfnetlink_log",
695         .logfn  = &nfulnl_log_packet,
696         .me     = THIS_MODULE,
697 };
698
699 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
700         [NFULA_CFG_CMD]         = { .len = sizeof(struct nfulnl_msg_config_cmd) },
701         [NFULA_CFG_MODE]        = { .len = sizeof(struct nfulnl_msg_config_mode) },
702         [NFULA_CFG_TIMEOUT]     = { .type = NLA_U32 },
703         [NFULA_CFG_QTHRESH]     = { .type = NLA_U32 },
704         [NFULA_CFG_NLBUFSIZ]    = { .type = NLA_U32 },
705         [NFULA_CFG_FLAGS]       = { .type = NLA_U16 },
706 };
707
708 static int
709 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
710                    struct nlmsghdr *nlh, struct nlattr *nfula[])
711 {
712         struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
713         u_int16_t group_num = ntohs(nfmsg->res_id);
714         struct nfulnl_instance *inst;
715         struct nfulnl_msg_config_cmd *cmd = NULL;
716         int ret = 0;
717
718         if (nfula[NFULA_CFG_CMD]) {
719                 u_int8_t pf = nfmsg->nfgen_family;
720                 cmd = nla_data(nfula[NFULA_CFG_CMD]);
721
722                 /* Commands without queue context */
723                 switch (cmd->command) {
724                 case NFULNL_CFG_CMD_PF_BIND:
725                         return nf_log_register(pf, &nfulnl_logger);
726                 case NFULNL_CFG_CMD_PF_UNBIND:
727                         nf_log_unregister_pf(pf);
728                         return 0;
729                 }
730         }
731
732         inst = instance_lookup_get(group_num);
733         if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
734                 ret = -EPERM;
735                 goto out_put;
736         }
737
738         if (cmd != NULL) {
739                 switch (cmd->command) {
740                 case NFULNL_CFG_CMD_BIND:
741                         if (inst) {
742                                 ret = -EBUSY;
743                                 goto out_put;
744                         }
745
746                         inst = instance_create(group_num,
747                                                NETLINK_CB(skb).pid);
748                         if (IS_ERR(inst)) {
749                                 ret = PTR_ERR(inst);
750                                 goto out;
751                         }
752                         break;
753                 case NFULNL_CFG_CMD_UNBIND:
754                         if (!inst) {
755                                 ret = -ENODEV;
756                                 goto out;
757                         }
758
759                         instance_destroy(inst);
760                         goto out;
761                 default:
762                         ret = -ENOTSUPP;
763                         break;
764                 }
765         }
766
767         if (nfula[NFULA_CFG_MODE]) {
768                 struct nfulnl_msg_config_mode *params;
769                 params = nla_data(nfula[NFULA_CFG_MODE]);
770
771                 if (!inst) {
772                         ret = -ENODEV;
773                         goto out;
774                 }
775                 nfulnl_set_mode(inst, params->copy_mode,
776                                 ntohl(params->copy_range));
777         }
778
779         if (nfula[NFULA_CFG_TIMEOUT]) {
780                 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
781
782                 if (!inst) {
783                         ret = -ENODEV;
784                         goto out;
785                 }
786                 nfulnl_set_timeout(inst, ntohl(timeout));
787         }
788
789         if (nfula[NFULA_CFG_NLBUFSIZ]) {
790                 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
791
792                 if (!inst) {
793                         ret = -ENODEV;
794                         goto out;
795                 }
796                 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
797         }
798
799         if (nfula[NFULA_CFG_QTHRESH]) {
800                 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
801
802                 if (!inst) {
803                         ret = -ENODEV;
804                         goto out;
805                 }
806                 nfulnl_set_qthresh(inst, ntohl(qthresh));
807         }
808
809         if (nfula[NFULA_CFG_FLAGS]) {
810                 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
811
812                 if (!inst) {
813                         ret = -ENODEV;
814                         goto out;
815                 }
816                 nfulnl_set_flags(inst, ntohs(flags));
817         }
818
819 out_put:
820         instance_put(inst);
821 out:
822         return ret;
823 }
824
825 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
826         [NFULNL_MSG_PACKET]     = { .call = nfulnl_recv_unsupp,
827                                     .attr_count = NFULA_MAX, },
828         [NFULNL_MSG_CONFIG]     = { .call = nfulnl_recv_config,
829                                     .attr_count = NFULA_CFG_MAX,
830                                     .policy = nfula_cfg_policy },
831 };
832
833 static const struct nfnetlink_subsystem nfulnl_subsys = {
834         .name           = "log",
835         .subsys_id      = NFNL_SUBSYS_ULOG,
836         .cb_count       = NFULNL_MSG_MAX,
837         .cb             = nfulnl_cb,
838 };
839
840 #ifdef CONFIG_PROC_FS
841 struct iter_state {
842         unsigned int bucket;
843 };
844
845 static struct hlist_node *get_first(struct iter_state *st)
846 {
847         if (!st)
848                 return NULL;
849
850         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
851                 if (!hlist_empty(&instance_table[st->bucket]))
852                         return instance_table[st->bucket].first;
853         }
854         return NULL;
855 }
856
857 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
858 {
859         h = h->next;
860         while (!h) {
861                 if (++st->bucket >= INSTANCE_BUCKETS)
862                         return NULL;
863
864                 h = instance_table[st->bucket].first;
865         }
866         return h;
867 }
868
869 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
870 {
871         struct hlist_node *head;
872         head = get_first(st);
873
874         if (head)
875                 while (pos && (head = get_next(st, head)))
876                         pos--;
877         return pos ? NULL : head;
878 }
879
880 static void *seq_start(struct seq_file *seq, loff_t *pos)
881         __acquires(instances_lock)
882 {
883         read_lock_bh(&instances_lock);
884         return get_idx(seq->private, *pos);
885 }
886
887 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
888 {
889         (*pos)++;
890         return get_next(s->private, v);
891 }
892
893 static void seq_stop(struct seq_file *s, void *v)
894         __releases(instances_lock)
895 {
896         read_unlock_bh(&instances_lock);
897 }
898
899 static int seq_show(struct seq_file *s, void *v)
900 {
901         const struct nfulnl_instance *inst = v;
902
903         return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
904                           inst->group_num,
905                           inst->peer_pid, inst->qlen,
906                           inst->copy_mode, inst->copy_range,
907                           inst->flushtimeout, atomic_read(&inst->use));
908 }
909
910 static const struct seq_operations nful_seq_ops = {
911         .start  = seq_start,
912         .next   = seq_next,
913         .stop   = seq_stop,
914         .show   = seq_show,
915 };
916
917 static int nful_open(struct inode *inode, struct file *file)
918 {
919         return seq_open_private(file, &nful_seq_ops,
920                         sizeof(struct iter_state));
921 }
922
923 static const struct file_operations nful_file_ops = {
924         .owner   = THIS_MODULE,
925         .open    = nful_open,
926         .read    = seq_read,
927         .llseek  = seq_lseek,
928         .release = seq_release_private,
929 };
930
931 #endif /* PROC_FS */
932
933 static int __init nfnetlink_log_init(void)
934 {
935         int i, status = -ENOMEM;
936
937         for (i = 0; i < INSTANCE_BUCKETS; i++)
938                 INIT_HLIST_HEAD(&instance_table[i]);
939
940         /* it's not really all that important to have a random value, so
941          * we can do this from the init function, even if there hasn't
942          * been that much entropy yet */
943         get_random_bytes(&hash_init, sizeof(hash_init));
944
945         netlink_register_notifier(&nfulnl_rtnl_notifier);
946         status = nfnetlink_subsys_register(&nfulnl_subsys);
947         if (status < 0) {
948                 printk(KERN_ERR "log: failed to create netlink socket\n");
949                 goto cleanup_netlink_notifier;
950         }
951
952 #ifdef CONFIG_PROC_FS
953         if (!proc_create("nfnetlink_log", 0440,
954                          proc_net_netfilter, &nful_file_ops))
955                 goto cleanup_subsys;
956 #endif
957         return status;
958
959 #ifdef CONFIG_PROC_FS
960 cleanup_subsys:
961         nfnetlink_subsys_unregister(&nfulnl_subsys);
962 #endif
963 cleanup_netlink_notifier:
964         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
965         return status;
966 }
967
968 static void __exit nfnetlink_log_fini(void)
969 {
970         nf_log_unregister(&nfulnl_logger);
971 #ifdef CONFIG_PROC_FS
972         remove_proc_entry("nfnetlink_log", proc_net_netfilter);
973 #endif
974         nfnetlink_subsys_unregister(&nfulnl_subsys);
975         netlink_unregister_notifier(&nfulnl_rtnl_notifier);
976 }
977
978 MODULE_DESCRIPTION("netfilter userspace logging");
979 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
980 MODULE_LICENSE("GPL");
981 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
982
983 module_init(nfnetlink_log_init);
984 module_exit(nfnetlink_log_fini);