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[NETFILTER]: nf_conntrack_tcp: make sysctl variables static
[linux-2.6/zen-sources.git] / net / netfilter / nfnetlink_log.c
blobb8eab0dbc3dd3f3a93f6af25317dc1c5e7f2f98b
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 * 2006-01-26 Harald Welte <laforge@netfilter.org>
15 * - Add optional local and global sequence number to detect lost
16 * events from userspace
17 *
18 */
19 #include <linux/module.h>
20 #include <linux/skbuff.h>
21 #include <linux/init.h>
22 #include <linux/ip.h>
23 #include <linux/ipv6.h>
24 #include <linux/netdevice.h>
25 #include <linux/netfilter.h>
26 #include <linux/netlink.h>
27 #include <linux/netfilter/nfnetlink.h>
28 #include <linux/netfilter/nfnetlink_log.h>
29 #include <linux/spinlock.h>
30 #include <linux/sysctl.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/list.h>
34 #include <linux/jhash.h>
35 #include <linux/random.h>
36 #include <net/sock.h>
37
38 #include <asm/atomic.h>
39
40 #ifdef CONFIG_BRIDGE_NETFILTER
41 #include "../bridge/br_private.h"
42 #endif
43
44 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
45 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
46 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
47
48 #define PRINTR(x, args...) do { if (net_ratelimit()) \
49 printk(x, ## args); } while (0);
50
51 #if 0
52 #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
53 __FILE__, __LINE__, __FUNCTION__, \
54 ## args)
55 #else
56 #define UDEBUG(x, ...)
57 #endif
58
59 struct nfulnl_instance {
60 struct hlist_node hlist; /* global list of instances */
61 spinlock_t lock;
62 atomic_t use; /* use count */
63
64 unsigned int qlen; /* number of nlmsgs in skb */
65 struct sk_buff *skb; /* pre-allocatd skb */
66 struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
67 struct timer_list timer;
68 int peer_pid; /* PID of the peer process */
69
70 /* configurable parameters */
71 unsigned int flushtimeout; /* timeout until queue flush */
72 unsigned int nlbufsiz; /* netlink buffer allocation size */
73 unsigned int qthreshold; /* threshold of the queue */
74 u_int32_t copy_range;
75 u_int32_t seq; /* instance-local sequential counter */
76 u_int16_t group_num; /* number of this queue */
77 u_int16_t flags;
78 u_int8_t copy_mode;
79 };
80
81 static DEFINE_RWLOCK(instances_lock);
82 static atomic_t global_seq;
83
84 #define INSTANCE_BUCKETS 16
85 static struct hlist_head instance_table[INSTANCE_BUCKETS];
86 static unsigned int hash_init;
87
88 static inline u_int8_t instance_hashfn(u_int16_t group_num)
89 {
90 return ((group_num & 0xff) % INSTANCE_BUCKETS);
91 }
92
93 static struct nfulnl_instance *
94 __instance_lookup(u_int16_t group_num)
95 {
96 struct hlist_head *head;
97 struct hlist_node *pos;
98 struct nfulnl_instance *inst;
99
100 UDEBUG("entering (group_num=%u)\n", group_num);
101
102 head = &instance_table[instance_hashfn(group_num)];
103 hlist_for_each_entry(inst, pos, head, hlist) {
104 if (inst->group_num == group_num)
105 return inst;
106 }
107 return NULL;
108 }
109
110 static inline void
111 instance_get(struct nfulnl_instance *inst)
112 {
113 atomic_inc(&inst->use);
114 }
115
116 static struct nfulnl_instance *
117 instance_lookup_get(u_int16_t group_num)
118 {
119 struct nfulnl_instance *inst;
120
121 read_lock_bh(&instances_lock);
122 inst = __instance_lookup(group_num);
123 if (inst)
124 instance_get(inst);
125 read_unlock_bh(&instances_lock);
126
127 return inst;
128 }
129
130 static void
131 instance_put(struct nfulnl_instance *inst)
132 {
133 if (inst && atomic_dec_and_test(&inst->use)) {
134 UDEBUG("kfree(inst=%p)\n", inst);
135 kfree(inst);
136 }
137 }
138
139 static void nfulnl_timer(unsigned long data);
140
141 static struct nfulnl_instance *
142 instance_create(u_int16_t group_num, int pid)
143 {
144 struct nfulnl_instance *inst;
145
146 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
147 pid);
148
149 write_lock_bh(&instances_lock);
150 if (__instance_lookup(group_num)) {
151 inst = NULL;
152 UDEBUG("aborting, instance already exists\n");
153 goto out_unlock;
154 }
155
156 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
157 if (!inst)
158 goto out_unlock;
159
160 INIT_HLIST_NODE(&inst->hlist);
161 spin_lock_init(&inst->lock);
162 /* needs to be two, since we _put() after creation */
163 atomic_set(&inst->use, 2);
164
165 init_timer(&inst->timer);
166 inst->timer.function = nfulnl_timer;
167 inst->timer.data = (unsigned long)inst;
168 /* don't start timer yet. (re)start it with every packet */
169
170 inst->peer_pid = pid;
171 inst->group_num = group_num;
172
173 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
174 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
175 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
176 inst->copy_mode = NFULNL_COPY_PACKET;
177 inst->copy_range = 0xffff;
178
179 if (!try_module_get(THIS_MODULE))
180 goto out_free;
181
182 hlist_add_head(&inst->hlist,
183 &instance_table[instance_hashfn(group_num)]);
184
185 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
186 inst->hlist.next);
187
188 write_unlock_bh(&instances_lock);
189
190 return inst;
191
192 out_free:
193 instance_put(inst);
194 out_unlock:
195 write_unlock_bh(&instances_lock);
196 return NULL;
197 }
198
199 static int __nfulnl_send(struct nfulnl_instance *inst);
200
201 static void
202 _instance_destroy2(struct nfulnl_instance *inst, int lock)
203 {
204 /* first pull it out of the global list */
205 if (lock)
206 write_lock_bh(&instances_lock);
207
208 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
209 inst, inst->group_num);
210
211 hlist_del(&inst->hlist);
212
213 if (lock)
214 write_unlock_bh(&instances_lock);
215
216 /* then flush all pending packets from skb */
217
218 spin_lock_bh(&inst->lock);
219 if (inst->skb) {
220 if (inst->qlen)
221 __nfulnl_send(inst);
222 if (inst->skb) {
223 kfree_skb(inst->skb);
224 inst->skb = NULL;
225 }
226 }
227 spin_unlock_bh(&inst->lock);
228
229 /* and finally put the refcount */
230 instance_put(inst);
231
232 module_put(THIS_MODULE);
233 }
234
235 static inline void
236 __instance_destroy(struct nfulnl_instance *inst)
237 {
238 _instance_destroy2(inst, 0);
239 }
240
241 static inline void
242 instance_destroy(struct nfulnl_instance *inst)
243 {
244 _instance_destroy2(inst, 1);
245 }
246
247 static int
248 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
249 unsigned int range)
250 {
251 int status = 0;
252
253 spin_lock_bh(&inst->lock);
254
255 switch (mode) {
256 case NFULNL_COPY_NONE:
257 case NFULNL_COPY_META:
258 inst->copy_mode = mode;
259 inst->copy_range = 0;
260 break;
261
262 case NFULNL_COPY_PACKET:
263 inst->copy_mode = mode;
264 /* we're using struct nfattr which has 16bit nfa_len */
265 if (range > 0xffff)
266 inst->copy_range = 0xffff;
267 else
268 inst->copy_range = range;
269 break;
270
271 default:
272 status = -EINVAL;
273 break;
274 }
275
276 spin_unlock_bh(&inst->lock);
277
278 return status;
279 }
280
281 static int
282 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
283 {
284 int status;
285
286 spin_lock_bh(&inst->lock);
287 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
288 status = -ERANGE;
289 else if (nlbufsiz > 131072)
290 status = -ERANGE;
291 else {
292 inst->nlbufsiz = nlbufsiz;
293 status = 0;
294 }
295 spin_unlock_bh(&inst->lock);
296
297 return status;
298 }
299
300 static int
301 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
302 {
303 spin_lock_bh(&inst->lock);
304 inst->flushtimeout = timeout;
305 spin_unlock_bh(&inst->lock);
306
307 return 0;
308 }
309
310 static int
311 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
312 {
313 spin_lock_bh(&inst->lock);
314 inst->qthreshold = qthresh;
315 spin_unlock_bh(&inst->lock);
316
317 return 0;
318 }
319
320 static int
321 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
322 {
323 spin_lock_bh(&inst->lock);
324 inst->flags = flags;
325 spin_unlock_bh(&inst->lock);
326
327 return 0;
328 }
329
330 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
331 unsigned int pkt_size)
332 {
333 struct sk_buff *skb;
334 unsigned int n;
335
336 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
337
338 /* alloc skb which should be big enough for a whole multipart
339 * message. WARNING: has to be <= 128k due to slab restrictions */
340
341 n = max(inst_size, pkt_size);
342 skb = alloc_skb(n, GFP_ATOMIC);
343 if (!skb) {
344 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
345 inst_size);
346
347 if (n > pkt_size) {
348 /* try to allocate only as much as we need for current
349 * packet */
350
351 skb = alloc_skb(pkt_size, GFP_ATOMIC);
352 if (!skb)
353 PRINTR("nfnetlink_log: can't even alloc %u "
354 "bytes\n", pkt_size);
355 }
356 }
357
358 return skb;
359 }
360
361 static int
362 __nfulnl_send(struct nfulnl_instance *inst)
363 {
364 int status;
365
366 if (timer_pending(&inst->timer))
367 del_timer(&inst->timer);
368
369 if (!inst->skb)
370 return 0;
371
372 if (inst->qlen > 1)
373 inst->lastnlh->nlmsg_type = NLMSG_DONE;
374
375 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
376 if (status < 0) {
377 UDEBUG("netlink_unicast() failed\n");
378 /* FIXME: statistics */
379 }
380
381 inst->qlen = 0;
382 inst->skb = NULL;
383 inst->lastnlh = NULL;
384
385 return status;
386 }
387
388 static void nfulnl_timer(unsigned long data)
389 {
390 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
391
392 UDEBUG("timer function called, flushing buffer\n");
393
394 spin_lock_bh(&inst->lock);
395 __nfulnl_send(inst);
396 instance_put(inst);
397 spin_unlock_bh(&inst->lock);
398 }
399
400 /* This is an inline function, we don't really care about a long
401 * list of arguments */
402 static inline int
403 __build_packet_message(struct nfulnl_instance *inst,
404 const struct sk_buff *skb,
405 unsigned int data_len,
406 unsigned int pf,
407 unsigned int hooknum,
408 const struct net_device *indev,
409 const struct net_device *outdev,
410 const struct nf_loginfo *li,
411 const char *prefix, unsigned int plen)
412 {
413 unsigned char *old_tail;
414 struct nfulnl_msg_packet_hdr pmsg;
415 struct nlmsghdr *nlh;
416 struct nfgenmsg *nfmsg;
417 __be32 tmp_uint;
418
419 UDEBUG("entered\n");
420
421 old_tail = inst->skb->tail;
422 nlh = NLMSG_PUT(inst->skb, 0, 0,
423 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
424 sizeof(struct nfgenmsg));
425 nfmsg = NLMSG_DATA(nlh);
426 nfmsg->nfgen_family = pf;
427 nfmsg->version = NFNETLINK_V0;
428 nfmsg->res_id = htons(inst->group_num);
429
430 pmsg.hw_protocol = skb->protocol;
431 pmsg.hook = hooknum;
432
433 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
434
435 if (prefix)
436 NFA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
437
438 if (indev) {
439 tmp_uint = htonl(indev->ifindex);
440 #ifndef CONFIG_BRIDGE_NETFILTER
441 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
442 &tmp_uint);
443 #else
444 if (pf == PF_BRIDGE) {
445 /* Case 1: outdev is physical input device, we need to
446 * look for bridge group (when called from
447 * netfilter_bridge) */
448 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
449 sizeof(tmp_uint), &tmp_uint);
450 /* this is the bridge group "brX" */
451 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
452 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
453 sizeof(tmp_uint), &tmp_uint);
454 } else {
455 /* Case 2: indev is bridge group, we need to look for
456 * physical device (when called from ipv4) */
457 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
458 sizeof(tmp_uint), &tmp_uint);
459 if (skb->nf_bridge && skb->nf_bridge->physindev) {
460 tmp_uint =
461 htonl(skb->nf_bridge->physindev->ifindex);
462 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
463 sizeof(tmp_uint), &tmp_uint);
464 }
465 }
466 #endif
467 }
468
469 if (outdev) {
470 tmp_uint = htonl(outdev->ifindex);
471 #ifndef CONFIG_BRIDGE_NETFILTER
472 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
473 &tmp_uint);
474 #else
475 if (pf == PF_BRIDGE) {
476 /* Case 1: outdev is physical output device, we need to
477 * look for bridge group (when called from
478 * netfilter_bridge) */
479 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
480 sizeof(tmp_uint), &tmp_uint);
481 /* this is the bridge group "brX" */
482 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
483 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
484 sizeof(tmp_uint), &tmp_uint);
485 } else {
486 /* Case 2: indev is a bridge group, we need to look
487 * for physical device (when called from ipv4) */
488 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
489 sizeof(tmp_uint), &tmp_uint);
490 if (skb->nf_bridge) {
491 tmp_uint =
492 htonl(skb->nf_bridge->physoutdev->ifindex);
493 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
494 sizeof(tmp_uint), &tmp_uint);
495 }
496 }
497 #endif
498 }
499
500 if (skb->mark) {
501 tmp_uint = htonl(skb->mark);
502 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
503 }
504
505 if (indev && skb->dev && skb->dev->hard_header_parse) {
506 struct nfulnl_msg_packet_hw phw;
507 int len = skb->dev->hard_header_parse((struct sk_buff *)skb,
508 phw.hw_addr);
509 phw.hw_addrlen = htons(len);
510 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
511 }
512
513 if (skb->tstamp.off_sec) {
514 struct nfulnl_msg_packet_timestamp ts;
515
516 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
517 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
518
519 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
520 }
521
522 /* UID */
523 if (skb->sk) {
524 read_lock_bh(&skb->sk->sk_callback_lock);
525 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
526 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
527 /* need to unlock here since NFA_PUT may goto */
528 read_unlock_bh(&skb->sk->sk_callback_lock);
529 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
530 } else
531 read_unlock_bh(&skb->sk->sk_callback_lock);
532 }
533
534 /* local sequence number */
535 if (inst->flags & NFULNL_CFG_F_SEQ) {
536 tmp_uint = htonl(inst->seq++);
537 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
538 }
539 /* global sequence number */
540 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
541 tmp_uint = htonl(atomic_inc_return(&global_seq));
542 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
543 }
544
545 if (data_len) {
546 struct nfattr *nfa;
547 int size = NFA_LENGTH(data_len);
548
549 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
550 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
551 goto nlmsg_failure;
552 }
553
554 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
555 nfa->nfa_type = NFULA_PAYLOAD;
556 nfa->nfa_len = size;
557
558 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
559 BUG();
560 }
561
562 nlh->nlmsg_len = inst->skb->tail - old_tail;
563 return 0;
564
565 nlmsg_failure:
566 UDEBUG("nlmsg_failure\n");
567 nfattr_failure:
568 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
569 return -1;
570 }
571
572 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
573
574 static struct nf_loginfo default_loginfo = {
575 .type = NF_LOG_TYPE_ULOG,
576 .u = {
577 .ulog = {
578 .copy_len = 0xffff,
579 .group = 0,
580 .qthreshold = 1,
581 },
582 },
583 };
584
585 /* log handler for internal netfilter logging api */
586 static void
587 nfulnl_log_packet(unsigned int pf,
588 unsigned int hooknum,
589 const struct sk_buff *skb,
590 const struct net_device *in,
591 const struct net_device *out,
592 const struct nf_loginfo *li_user,
593 const char *prefix)
594 {
595 unsigned int size, data_len;
596 struct nfulnl_instance *inst;
597 const struct nf_loginfo *li;
598 unsigned int qthreshold;
599 unsigned int nlbufsiz;
600 unsigned int plen;
601
602 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
603 li = li_user;
604 else
605 li = &default_loginfo;
606
607 inst = instance_lookup_get(li->u.ulog.group);
608 if (!inst)
609 inst = instance_lookup_get(0);
610 if (!inst) {
611 PRINTR("nfnetlink_log: trying to log packet, "
612 "but no instance for group %u\n", li->u.ulog.group);
613 return;
614 }
615
616 plen = 0;
617 if (prefix)
618 plen = strlen(prefix);
619
620 /* all macros expand to constant values at compile time */
621 /* FIXME: do we want to make the size calculation conditional based on
622 * what is actually present? way more branches and checks, but more
623 * memory efficient... */
624 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
625 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
626 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
627 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
628 #ifdef CONFIG_BRIDGE_NETFILTER
629 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
630 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
631 #endif
632 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
633 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
634 + NFA_SPACE(plen) /* prefix */
635 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
636 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
637
638 UDEBUG("initial size=%u\n", size);
639
640 spin_lock_bh(&inst->lock);
641
642 if (inst->flags & NFULNL_CFG_F_SEQ)
643 size += NFA_SPACE(sizeof(u_int32_t));
644 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
645 size += NFA_SPACE(sizeof(u_int32_t));
646
647 qthreshold = inst->qthreshold;
648 /* per-rule qthreshold overrides per-instance */
649 if (qthreshold > li->u.ulog.qthreshold)
650 qthreshold = li->u.ulog.qthreshold;
651
652 switch (inst->copy_mode) {
653 case NFULNL_COPY_META:
654 case NFULNL_COPY_NONE:
655 data_len = 0;
656 break;
657
658 case NFULNL_COPY_PACKET:
659 if (inst->copy_range == 0
660 || inst->copy_range > skb->len)
661 data_len = skb->len;
662 else
663 data_len = inst->copy_range;
664
665 size += NFA_SPACE(data_len);
666 UDEBUG("copy_packet, therefore size now %u\n", size);
667 break;
668
669 default:
670 spin_unlock_bh(&inst->lock);
671 instance_put(inst);
672 return;
673 }
674
675 if (size > inst->nlbufsiz)
676 nlbufsiz = size;
677 else
678 nlbufsiz = inst->nlbufsiz;
679
680 if (!inst->skb) {
681 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
682 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
683 inst->nlbufsiz, size);
684 goto alloc_failure;
685 }
686 } else if (inst->qlen >= qthreshold ||
687 size > skb_tailroom(inst->skb)) {
688 /* either the queue len is too high or we don't have
689 * enough room in the skb left. flush to userspace. */
690 UDEBUG("flushing old skb\n");
691
692 __nfulnl_send(inst);
693
694 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
695 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
696 inst->nlbufsiz, size);
697 goto alloc_failure;
698 }
699 }
700
701 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
702 inst->qlen++;
703
704 __build_packet_message(inst, skb, data_len, pf,
705 hooknum, in, out, li, prefix, plen);
706
707 /* timer_pending always called within inst->lock, so there
708 * is no chance of a race here */
709 if (!timer_pending(&inst->timer)) {
710 instance_get(inst);
711 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
712 add_timer(&inst->timer);
713 }
714 spin_unlock_bh(&inst->lock);
715
716 return;
717
718 alloc_failure:
719 spin_unlock_bh(&inst->lock);
720 instance_put(inst);
721 UDEBUG("error allocating skb\n");
722 /* FIXME: statistics */
723 }
724
725 static int
726 nfulnl_rcv_nl_event(struct notifier_block *this,
727 unsigned long event, void *ptr)
728 {
729 struct netlink_notify *n = ptr;
730
731 if (event == NETLINK_URELEASE &&
732 n->protocol == NETLINK_NETFILTER && n->pid) {
733 int i;
734
735 /* destroy all instances for this pid */
736 write_lock_bh(&instances_lock);
737 for (i = 0; i < INSTANCE_BUCKETS; i++) {
738 struct hlist_node *tmp, *t2;
739 struct nfulnl_instance *inst;
740 struct hlist_head *head = &instance_table[i];
741
742 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
743 UDEBUG("node = %p\n", inst);
744 if (n->pid == inst->peer_pid)
745 __instance_destroy(inst);
746 }
747 }
748 write_unlock_bh(&instances_lock);
749 }
750 return NOTIFY_DONE;
751 }
752
753 static struct notifier_block nfulnl_rtnl_notifier = {
754 .notifier_call = nfulnl_rcv_nl_event,
755 };
756
757 static int
758 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
759 struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
760 {
761 return -ENOTSUPP;
762 }
763
764 static struct nf_logger nfulnl_logger = {
765 .name = "nfnetlink_log",
766 .logfn = &nfulnl_log_packet,
767 .me = THIS_MODULE,
768 };
769
770 static const int nfula_min[NFULA_MAX] = {
771 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
772 [NFULA_MARK-1] = sizeof(u_int32_t),
773 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
774 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
775 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
776 [NFULA_IFINDEX_PHYSINDEV-1] = sizeof(u_int32_t),
777 [NFULA_IFINDEX_PHYSOUTDEV-1] = sizeof(u_int32_t),
778 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
779 [NFULA_PAYLOAD-1] = 0,
780 [NFULA_PREFIX-1] = 0,
781 [NFULA_UID-1] = sizeof(u_int32_t),
782 [NFULA_SEQ-1] = sizeof(u_int32_t),
783 [NFULA_SEQ_GLOBAL-1] = sizeof(u_int32_t),
784 };
785
786 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
787 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
788 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
789 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
790 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
791 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
792 [NFULA_CFG_FLAGS-1] = sizeof(u_int16_t),
793 };
794
795 static int
796 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
797 struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
798 {
799 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
800 u_int16_t group_num = ntohs(nfmsg->res_id);
801 struct nfulnl_instance *inst;
802 int ret = 0;
803
804 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
805
806 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
807 UDEBUG("bad attribute size\n");
808 return -EINVAL;
809 }
810
811 inst = instance_lookup_get(group_num);
812 if (nfula[NFULA_CFG_CMD-1]) {
813 u_int8_t pf = nfmsg->nfgen_family;
814 struct nfulnl_msg_config_cmd *cmd;
815 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
816 UDEBUG("found CFG_CMD for\n");
817
818 switch (cmd->command) {
819 case NFULNL_CFG_CMD_BIND:
820 if (inst) {
821 ret = -EBUSY;
822 goto out_put;
823 }
824
825 inst = instance_create(group_num,
826 NETLINK_CB(skb).pid);
827 if (!inst) {
828 ret = -EINVAL;
829 goto out_put;
830 }
831 break;
832 case NFULNL_CFG_CMD_UNBIND:
833 if (!inst) {
834 ret = -ENODEV;
835 goto out_put;
836 }
837
838 if (inst->peer_pid != NETLINK_CB(skb).pid) {
839 ret = -EPERM;
840 goto out_put;
841 }
842
843 instance_destroy(inst);
844 break;
845 case NFULNL_CFG_CMD_PF_BIND:
846 UDEBUG("registering log handler for pf=%u\n", pf);
847 ret = nf_log_register(pf, &nfulnl_logger);
848 break;
849 case NFULNL_CFG_CMD_PF_UNBIND:
850 UDEBUG("unregistering log handler for pf=%u\n", pf);
851 /* This is a bug and a feature. We cannot unregister
852 * other handlers, like nfnetlink_inst can */
853 nf_log_unregister_pf(pf);
854 break;
855 default:
856 ret = -EINVAL;
857 break;
858 }
859 } else {
860 if (!inst) {
861 UDEBUG("no config command, and no instance for "
862 "group=%u pid=%u =>ENOENT\n",
863 group_num, NETLINK_CB(skb).pid);
864 ret = -ENOENT;
865 goto out_put;
866 }
867
868 if (inst->peer_pid != NETLINK_CB(skb).pid) {
869 UDEBUG("no config command, and wrong pid\n");
870 ret = -EPERM;
871 goto out_put;
872 }
873 }
874
875 if (nfula[NFULA_CFG_MODE-1]) {
876 struct nfulnl_msg_config_mode *params;
877 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
878
879 nfulnl_set_mode(inst, params->copy_mode,
880 ntohl(params->copy_range));
881 }
882
883 if (nfula[NFULA_CFG_TIMEOUT-1]) {
884 __be32 timeout =
885 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
886
887 nfulnl_set_timeout(inst, ntohl(timeout));
888 }
889
890 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
891 __be32 nlbufsiz =
892 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
893
894 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
895 }
896
897 if (nfula[NFULA_CFG_QTHRESH-1]) {
898 __be32 qthresh =
899 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
900
901 nfulnl_set_qthresh(inst, ntohl(qthresh));
902 }
903
904 if (nfula[NFULA_CFG_FLAGS-1]) {
905 __be16 flags =
906 *(__be16 *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
907 nfulnl_set_flags(inst, ntohs(flags));
908 }
909
910 out_put:
911 instance_put(inst);
912 return ret;
913 }
914
915 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
916 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
917 .attr_count = NFULA_MAX, },
918 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
919 .attr_count = NFULA_CFG_MAX, },
920 };
921
922 static struct nfnetlink_subsystem nfulnl_subsys = {
923 .name = "log",
924 .subsys_id = NFNL_SUBSYS_ULOG,
925 .cb_count = NFULNL_MSG_MAX,
926 .cb = nfulnl_cb,
927 };
928
929 #ifdef CONFIG_PROC_FS
930 struct iter_state {
931 unsigned int bucket;
932 };
933
934 static struct hlist_node *get_first(struct seq_file *seq)
935 {
936 struct iter_state *st = seq->private;
937
938 if (!st)
939 return NULL;
940
941 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
942 if (!hlist_empty(&instance_table[st->bucket]))
943 return instance_table[st->bucket].first;
944 }
945 return NULL;
946 }
947
948 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
949 {
950 struct iter_state *st = seq->private;
951
952 h = h->next;
953 while (!h) {
954 if (++st->bucket >= INSTANCE_BUCKETS)
955 return NULL;
956
957 h = instance_table[st->bucket].first;
958 }
959 return h;
960 }
961
962 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
963 {
964 struct hlist_node *head;
965 head = get_first(seq);
966
967 if (head)
968 while (pos && (head = get_next(seq, head)))
969 pos--;
970 return pos ? NULL : head;
971 }
972
973 static void *seq_start(struct seq_file *seq, loff_t *pos)
974 {
975 read_lock_bh(&instances_lock);
976 return get_idx(seq, *pos);
977 }
978
979 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
980 {
981 (*pos)++;
982 return get_next(s, v);
983 }
984
985 static void seq_stop(struct seq_file *s, void *v)
986 {
987 read_unlock_bh(&instances_lock);
988 }
989
990 static int seq_show(struct seq_file *s, void *v)
991 {
992 const struct nfulnl_instance *inst = v;
993
994 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
995 inst->group_num,
996 inst->peer_pid, inst->qlen,
997 inst->copy_mode, inst->copy_range,
998 inst->flushtimeout, atomic_read(&inst->use));
999 }
1000
1001 static struct seq_operations nful_seq_ops = {
1002 .start = seq_start,
1003 .next = seq_next,
1004 .stop = seq_stop,
1005 .show = seq_show,
1006 };
1007
1008 static int nful_open(struct inode *inode, struct file *file)
1009 {
1010 struct seq_file *seq;
1011 struct iter_state *is;
1012 int ret;
1013
1014 is = kzalloc(sizeof(*is), GFP_KERNEL);
1015 if (!is)
1016 return -ENOMEM;
1017 ret = seq_open(file, &nful_seq_ops);
1018 if (ret < 0)
1019 goto out_free;
1020 seq = file->private_data;
1021 seq->private = is;
1022 return ret;
1023 out_free:
1024 kfree(is);
1025 return ret;
1026 }
1027
1028 static const struct file_operations nful_file_ops = {
1029 .owner = THIS_MODULE,
1030 .open = nful_open,
1031 .read = seq_read,
1032 .llseek = seq_lseek,
1033 .release = seq_release_private,
1034 };
1035
1036 #endif /* PROC_FS */
1037
1038 static int __init nfnetlink_log_init(void)
1039 {
1040 int i, status = -ENOMEM;
1041 #ifdef CONFIG_PROC_FS
1042 struct proc_dir_entry *proc_nful;
1043 #endif
1044
1045 for (i = 0; i < INSTANCE_BUCKETS; i++)
1046 INIT_HLIST_HEAD(&instance_table[i]);
1047
1048 /* it's not really all that important to have a random value, so
1049 * we can do this from the init function, even if there hasn't
1050 * been that much entropy yet */
1051 get_random_bytes(&hash_init, sizeof(hash_init));
1052
1053 netlink_register_notifier(&nfulnl_rtnl_notifier);
1054 status = nfnetlink_subsys_register(&nfulnl_subsys);
1055 if (status < 0) {
1056 printk(KERN_ERR "log: failed to create netlink socket\n");
1057 goto cleanup_netlink_notifier;
1058 }
1059
1060 #ifdef CONFIG_PROC_FS
1061 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1062 proc_net_netfilter);
1063 if (!proc_nful)
1064 goto cleanup_subsys;
1065 proc_nful->proc_fops = &nful_file_ops;
1066 #endif
1067 return status;
1068
1069 #ifdef CONFIG_PROC_FS
1070 cleanup_subsys:
1071 nfnetlink_subsys_unregister(&nfulnl_subsys);
1072 #endif
1073 cleanup_netlink_notifier:
1074 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1075 return status;
1076 }
1077
1078 static void __exit nfnetlink_log_fini(void)
1079 {
1080 nf_log_unregister(&nfulnl_logger);
1081 #ifdef CONFIG_PROC_FS
1082 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1083 #endif
1084 nfnetlink_subsys_unregister(&nfulnl_subsys);
1085 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1086 }
1087
1088 MODULE_DESCRIPTION("netfilter userspace logging");
1089 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1090 MODULE_LICENSE("GPL");
1091 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1092
1093 module_init(nfnetlink_log_init);
1094 module_exit(nfnetlink_log_fini);
Stable & featurefull patchset based on Linus's git branch