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Linux 2.6.17.7
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blob61cdda4e5d3ba8b25f02af19a7bbb634fc9a0d84
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->qlen > 1)
370 inst->lastnlh->nlmsg_type = NLMSG_DONE;
371
372 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
373 if (status < 0) {
374 UDEBUG("netlink_unicast() failed\n");
375 /* FIXME: statistics */
376 }
377
378 inst->qlen = 0;
379 inst->skb = NULL;
380 inst->lastnlh = NULL;
381
382 return status;
383 }
384
385 static void nfulnl_timer(unsigned long data)
386 {
387 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
388
389 UDEBUG("timer function called, flushing buffer\n");
390
391 spin_lock_bh(&inst->lock);
392 __nfulnl_send(inst);
393 instance_put(inst);
394 spin_unlock_bh(&inst->lock);
395 }
396
397 /* This is an inline function, we don't really care about a long
398 * list of arguments */
399 static inline int
400 __build_packet_message(struct nfulnl_instance *inst,
401 const struct sk_buff *skb,
402 unsigned int data_len,
403 unsigned int pf,
404 unsigned int hooknum,
405 const struct net_device *indev,
406 const struct net_device *outdev,
407 const struct nf_loginfo *li,
408 const char *prefix)
409 {
410 unsigned char *old_tail;
411 struct nfulnl_msg_packet_hdr pmsg;
412 struct nlmsghdr *nlh;
413 struct nfgenmsg *nfmsg;
414 u_int32_t tmp_uint;
415
416 UDEBUG("entered\n");
417
418 old_tail = inst->skb->tail;
419 nlh = NLMSG_PUT(inst->skb, 0, 0,
420 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
421 sizeof(struct nfgenmsg));
422 nfmsg = NLMSG_DATA(nlh);
423 nfmsg->nfgen_family = pf;
424 nfmsg->version = NFNETLINK_V0;
425 nfmsg->res_id = htons(inst->group_num);
426
427 pmsg.hw_protocol = htons(skb->protocol);
428 pmsg.hook = hooknum;
429
430 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
431
432 if (prefix) {
433 int slen = strlen(prefix);
434 if (slen > NFULNL_PREFIXLEN)
435 slen = NFULNL_PREFIXLEN;
436 NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
437 }
438
439 if (indev) {
440 tmp_uint = htonl(indev->ifindex);
441 #ifndef CONFIG_BRIDGE_NETFILTER
442 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
443 &tmp_uint);
444 #else
445 if (pf == PF_BRIDGE) {
446 /* Case 1: outdev is physical input device, we need to
447 * look for bridge group (when called from
448 * netfilter_bridge) */
449 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
450 sizeof(tmp_uint), &tmp_uint);
451 /* this is the bridge group "brX" */
452 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
453 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
454 sizeof(tmp_uint), &tmp_uint);
455 } else {
456 /* Case 2: indev is bridge group, we need to look for
457 * physical device (when called from ipv4) */
458 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
459 sizeof(tmp_uint), &tmp_uint);
460 if (skb->nf_bridge && skb->nf_bridge->physindev) {
461 tmp_uint =
462 htonl(skb->nf_bridge->physindev->ifindex);
463 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
464 sizeof(tmp_uint), &tmp_uint);
465 }
466 }
467 #endif
468 }
469
470 if (outdev) {
471 tmp_uint = htonl(outdev->ifindex);
472 #ifndef CONFIG_BRIDGE_NETFILTER
473 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
474 &tmp_uint);
475 #else
476 if (pf == PF_BRIDGE) {
477 /* Case 1: outdev is physical output device, we need to
478 * look for bridge group (when called from
479 * netfilter_bridge) */
480 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
481 sizeof(tmp_uint), &tmp_uint);
482 /* this is the bridge group "brX" */
483 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
484 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
485 sizeof(tmp_uint), &tmp_uint);
486 } else {
487 /* Case 2: indev is a bridge group, we need to look
488 * for physical device (when called from ipv4) */
489 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
490 sizeof(tmp_uint), &tmp_uint);
491 if (skb->nf_bridge) {
492 tmp_uint =
493 htonl(skb->nf_bridge->physoutdev->ifindex);
494 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
495 sizeof(tmp_uint), &tmp_uint);
496 }
497 }
498 #endif
499 }
500
501 if (skb->nfmark) {
502 tmp_uint = htonl(skb->nfmark);
503 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
504 }
505
506 if (indev && skb->dev && skb->dev->hard_header_parse) {
507 struct nfulnl_msg_packet_hw phw;
508
509 phw.hw_addrlen =
510 skb->dev->hard_header_parse((struct sk_buff *)skb,
511 phw.hw_addr);
512 phw.hw_addrlen = htons(phw.hw_addrlen);
513 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
514 }
515
516 if (skb->tstamp.off_sec) {
517 struct nfulnl_msg_packet_timestamp ts;
518
519 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
520 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
521
522 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
523 }
524
525 /* UID */
526 if (skb->sk) {
527 read_lock_bh(&skb->sk->sk_callback_lock);
528 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
529 u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
530 /* need to unlock here since NFA_PUT may goto */
531 read_unlock_bh(&skb->sk->sk_callback_lock);
532 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
533 } else
534 read_unlock_bh(&skb->sk->sk_callback_lock);
535 }
536
537 /* local sequence number */
538 if (inst->flags & NFULNL_CFG_F_SEQ) {
539 tmp_uint = htonl(inst->seq++);
540 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
541 }
542 /* global sequence number */
543 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
544 tmp_uint = atomic_inc_return(&global_seq);
545 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
546 }
547
548 if (data_len) {
549 struct nfattr *nfa;
550 int size = NFA_LENGTH(data_len);
551
552 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
553 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
554 goto nlmsg_failure;
555 }
556
557 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
558 nfa->nfa_type = NFULA_PAYLOAD;
559 nfa->nfa_len = size;
560
561 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
562 BUG();
563 }
564
565 nlh->nlmsg_len = inst->skb->tail - old_tail;
566 return 0;
567
568 nlmsg_failure:
569 UDEBUG("nlmsg_failure\n");
570 nfattr_failure:
571 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
572 return -1;
573 }
574
575 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
576
577 static struct nf_loginfo default_loginfo = {
578 .type = NF_LOG_TYPE_ULOG,
579 .u = {
580 .ulog = {
581 .copy_len = 0xffff,
582 .group = 0,
583 .qthreshold = 1,
584 },
585 },
586 };
587
588 /* log handler for internal netfilter logging api */
589 static void
590 nfulnl_log_packet(unsigned int pf,
591 unsigned int hooknum,
592 const struct sk_buff *skb,
593 const struct net_device *in,
594 const struct net_device *out,
595 const struct nf_loginfo *li_user,
596 const char *prefix)
597 {
598 unsigned int size, data_len;
599 struct nfulnl_instance *inst;
600 const struct nf_loginfo *li;
601 unsigned int qthreshold;
602 unsigned int nlbufsiz;
603
604 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
605 li = li_user;
606 else
607 li = &default_loginfo;
608
609 inst = instance_lookup_get(li->u.ulog.group);
610 if (!inst)
611 inst = instance_lookup_get(0);
612 if (!inst) {
613 PRINTR("nfnetlink_log: trying to log packet, "
614 "but no instance for group %u\n", li->u.ulog.group);
615 return;
616 }
617
618 /* all macros expand to constant values at compile time */
619 /* FIXME: do we want to make the size calculation conditional based on
620 * what is actually present? way more branches and checks, but more
621 * memory efficient... */
622 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
623 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
624 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
625 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
626 #ifdef CONFIG_BRIDGE_NETFILTER
627 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
628 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
629 #endif
630 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
631 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
632 + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */
633 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
634 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
635
636 UDEBUG("initial size=%u\n", size);
637
638 spin_lock_bh(&inst->lock);
639
640 if (inst->flags & NFULNL_CFG_F_SEQ)
641 size += NFA_SPACE(sizeof(u_int32_t));
642 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
643 size += NFA_SPACE(sizeof(u_int32_t));
644
645 qthreshold = inst->qthreshold;
646 /* per-rule qthreshold overrides per-instance */
647 if (qthreshold > li->u.ulog.qthreshold)
648 qthreshold = li->u.ulog.qthreshold;
649
650 switch (inst->copy_mode) {
651 case NFULNL_COPY_META:
652 case NFULNL_COPY_NONE:
653 data_len = 0;
654 break;
655
656 case NFULNL_COPY_PACKET:
657 if (inst->copy_range == 0
658 || inst->copy_range > skb->len)
659 data_len = skb->len;
660 else
661 data_len = inst->copy_range;
662
663 size += NFA_SPACE(data_len);
664 UDEBUG("copy_packet, therefore size now %u\n", size);
665 break;
666
667 default:
668 spin_unlock_bh(&inst->lock);
669 instance_put(inst);
670 return;
671 }
672
673 if (size > inst->nlbufsiz)
674 nlbufsiz = size;
675 else
676 nlbufsiz = inst->nlbufsiz;
677
678 if (!inst->skb) {
679 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
680 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
681 inst->nlbufsiz, size);
682 goto alloc_failure;
683 }
684 } else if (inst->qlen >= qthreshold ||
685 size > skb_tailroom(inst->skb)) {
686 /* either the queue len is too high or we don't have
687 * enough room in the skb left. flush to userspace. */
688 UDEBUG("flushing old skb\n");
689
690 __nfulnl_send(inst);
691
692 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
693 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
694 inst->nlbufsiz, size);
695 goto alloc_failure;
696 }
697 }
698
699 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
700 inst->qlen++;
701
702 __build_packet_message(inst, skb, data_len, pf,
703 hooknum, in, out, li, prefix);
704
705 /* timer_pending always called within inst->lock, so there
706 * is no chance of a race here */
707 if (!timer_pending(&inst->timer)) {
708 instance_get(inst);
709 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
710 add_timer(&inst->timer);
711 }
712 spin_unlock_bh(&inst->lock);
713
714 return;
715
716 alloc_failure:
717 spin_unlock_bh(&inst->lock);
718 instance_put(inst);
719 UDEBUG("error allocating skb\n");
720 /* FIXME: statistics */
721 }
722
723 static int
724 nfulnl_rcv_nl_event(struct notifier_block *this,
725 unsigned long event, void *ptr)
726 {
727 struct netlink_notify *n = ptr;
728
729 if (event == NETLINK_URELEASE &&
730 n->protocol == NETLINK_NETFILTER && n->pid) {
731 int i;
732
733 /* destroy all instances for this pid */
734 write_lock_bh(&instances_lock);
735 for (i = 0; i < INSTANCE_BUCKETS; i++) {
736 struct hlist_node *tmp, *t2;
737 struct nfulnl_instance *inst;
738 struct hlist_head *head = &instance_table[i];
739
740 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
741 UDEBUG("node = %p\n", inst);
742 if (n->pid == inst->peer_pid)
743 __instance_destroy(inst);
744 }
745 }
746 write_unlock_bh(&instances_lock);
747 }
748 return NOTIFY_DONE;
749 }
750
751 static struct notifier_block nfulnl_rtnl_notifier = {
752 .notifier_call = nfulnl_rcv_nl_event,
753 };
754
755 static int
756 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
757 struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
758 {
759 return -ENOTSUPP;
760 }
761
762 static struct nf_logger nfulnl_logger = {
763 .name = "nfnetlink_log",
764 .logfn = &nfulnl_log_packet,
765 .me = THIS_MODULE,
766 };
767
768 static const int nfula_min[NFULA_MAX] = {
769 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
770 [NFULA_MARK-1] = sizeof(u_int32_t),
771 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
772 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
773 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
774 [NFULA_IFINDEX_PHYSINDEV-1] = sizeof(u_int32_t),
775 [NFULA_IFINDEX_PHYSOUTDEV-1] = sizeof(u_int32_t),
776 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
777 [NFULA_PAYLOAD-1] = 0,
778 [NFULA_PREFIX-1] = 0,
779 [NFULA_UID-1] = sizeof(u_int32_t),
780 [NFULA_SEQ-1] = sizeof(u_int32_t),
781 [NFULA_SEQ_GLOBAL-1] = sizeof(u_int32_t),
782 };
783
784 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
785 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
786 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
787 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
788 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
789 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
790 [NFULA_CFG_FLAGS-1] = sizeof(u_int16_t),
791 };
792
793 static int
794 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
795 struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
796 {
797 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
798 u_int16_t group_num = ntohs(nfmsg->res_id);
799 struct nfulnl_instance *inst;
800 int ret = 0;
801
802 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
803
804 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
805 UDEBUG("bad attribute size\n");
806 return -EINVAL;
807 }
808
809 inst = instance_lookup_get(group_num);
810 if (nfula[NFULA_CFG_CMD-1]) {
811 u_int8_t pf = nfmsg->nfgen_family;
812 struct nfulnl_msg_config_cmd *cmd;
813 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
814 UDEBUG("found CFG_CMD for\n");
815
816 switch (cmd->command) {
817 case NFULNL_CFG_CMD_BIND:
818 if (inst) {
819 ret = -EBUSY;
820 goto out_put;
821 }
822
823 inst = instance_create(group_num,
824 NETLINK_CB(skb).pid);
825 if (!inst) {
826 ret = -EINVAL;
827 goto out_put;
828 }
829 break;
830 case NFULNL_CFG_CMD_UNBIND:
831 if (!inst) {
832 ret = -ENODEV;
833 goto out_put;
834 }
835
836 if (inst->peer_pid != NETLINK_CB(skb).pid) {
837 ret = -EPERM;
838 goto out_put;
839 }
840
841 instance_destroy(inst);
842 break;
843 case NFULNL_CFG_CMD_PF_BIND:
844 UDEBUG("registering log handler for pf=%u\n", pf);
845 ret = nf_log_register(pf, &nfulnl_logger);
846 break;
847 case NFULNL_CFG_CMD_PF_UNBIND:
848 UDEBUG("unregistering log handler for pf=%u\n", pf);
849 /* This is a bug and a feature. We cannot unregister
850 * other handlers, like nfnetlink_inst can */
851 nf_log_unregister_pf(pf);
852 break;
853 default:
854 ret = -EINVAL;
855 break;
856 }
857 } else {
858 if (!inst) {
859 UDEBUG("no config command, and no instance for "
860 "group=%u pid=%u =>ENOENT\n",
861 group_num, NETLINK_CB(skb).pid);
862 ret = -ENOENT;
863 goto out_put;
864 }
865
866 if (inst->peer_pid != NETLINK_CB(skb).pid) {
867 UDEBUG("no config command, and wrong pid\n");
868 ret = -EPERM;
869 goto out_put;
870 }
871 }
872
873 if (nfula[NFULA_CFG_MODE-1]) {
874 struct nfulnl_msg_config_mode *params;
875 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
876
877 nfulnl_set_mode(inst, params->copy_mode,
878 ntohs(params->copy_range));
879 }
880
881 if (nfula[NFULA_CFG_TIMEOUT-1]) {
882 u_int32_t timeout =
883 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
884
885 nfulnl_set_timeout(inst, ntohl(timeout));
886 }
887
888 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
889 u_int32_t nlbufsiz =
890 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
891
892 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
893 }
894
895 if (nfula[NFULA_CFG_QTHRESH-1]) {
896 u_int32_t qthresh =
897 *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
898
899 nfulnl_set_qthresh(inst, ntohl(qthresh));
900 }
901
902 if (nfula[NFULA_CFG_FLAGS-1]) {
903 u_int16_t flags =
904 *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
905 nfulnl_set_flags(inst, ntohs(flags));
906 }
907
908 out_put:
909 instance_put(inst);
910 return ret;
911 }
912
913 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
914 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
915 .attr_count = NFULA_MAX, },
916 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
917 .attr_count = NFULA_CFG_MAX, },
918 };
919
920 static struct nfnetlink_subsystem nfulnl_subsys = {
921 .name = "log",
922 .subsys_id = NFNL_SUBSYS_ULOG,
923 .cb_count = NFULNL_MSG_MAX,
924 .cb = nfulnl_cb,
925 };
926
927 #ifdef CONFIG_PROC_FS
928 struct iter_state {
929 unsigned int bucket;
930 };
931
932 static struct hlist_node *get_first(struct seq_file *seq)
933 {
934 struct iter_state *st = seq->private;
935
936 if (!st)
937 return NULL;
938
939 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
940 if (!hlist_empty(&instance_table[st->bucket]))
941 return instance_table[st->bucket].first;
942 }
943 return NULL;
944 }
945
946 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
947 {
948 struct iter_state *st = seq->private;
949
950 h = h->next;
951 while (!h) {
952 if (++st->bucket >= INSTANCE_BUCKETS)
953 return NULL;
954
955 h = instance_table[st->bucket].first;
956 }
957 return h;
958 }
959
960 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
961 {
962 struct hlist_node *head;
963 head = get_first(seq);
964
965 if (head)
966 while (pos && (head = get_next(seq, head)))
967 pos--;
968 return pos ? NULL : head;
969 }
970
971 static void *seq_start(struct seq_file *seq, loff_t *pos)
972 {
973 read_lock_bh(&instances_lock);
974 return get_idx(seq, *pos);
975 }
976
977 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
978 {
979 (*pos)++;
980 return get_next(s, v);
981 }
982
983 static void seq_stop(struct seq_file *s, void *v)
984 {
985 read_unlock_bh(&instances_lock);
986 }
987
988 static int seq_show(struct seq_file *s, void *v)
989 {
990 const struct nfulnl_instance *inst = v;
991
992 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
993 inst->group_num,
994 inst->peer_pid, inst->qlen,
995 inst->copy_mode, inst->copy_range,
996 inst->flushtimeout, atomic_read(&inst->use));
997 }
998
999 static struct seq_operations nful_seq_ops = {
1000 .start = seq_start,
1001 .next = seq_next,
1002 .stop = seq_stop,
1003 .show = seq_show,
1004 };
1005
1006 static int nful_open(struct inode *inode, struct file *file)
1007 {
1008 struct seq_file *seq;
1009 struct iter_state *is;
1010 int ret;
1011
1012 is = kzalloc(sizeof(*is), GFP_KERNEL);
1013 if (!is)
1014 return -ENOMEM;
1015 ret = seq_open(file, &nful_seq_ops);
1016 if (ret < 0)
1017 goto out_free;
1018 seq = file->private_data;
1019 seq->private = is;
1020 return ret;
1021 out_free:
1022 kfree(is);
1023 return ret;
1024 }
1025
1026 static struct file_operations nful_file_ops = {
1027 .owner = THIS_MODULE,
1028 .open = nful_open,
1029 .read = seq_read,
1030 .llseek = seq_lseek,
1031 .release = seq_release_private,
1032 };
1033
1034 #endif /* PROC_FS */
1035
1036 static int __init nfnetlink_log_init(void)
1037 {
1038 int i, status = -ENOMEM;
1039 #ifdef CONFIG_PROC_FS
1040 struct proc_dir_entry *proc_nful;
1041 #endif
1042
1043 for (i = 0; i < INSTANCE_BUCKETS; i++)
1044 INIT_HLIST_HEAD(&instance_table[i]);
1045
1046 /* it's not really all that important to have a random value, so
1047 * we can do this from the init function, even if there hasn't
1048 * been that much entropy yet */
1049 get_random_bytes(&hash_init, sizeof(hash_init));
1050
1051 netlink_register_notifier(&nfulnl_rtnl_notifier);
1052 status = nfnetlink_subsys_register(&nfulnl_subsys);
1053 if (status < 0) {
1054 printk(KERN_ERR "log: failed to create netlink socket\n");
1055 goto cleanup_netlink_notifier;
1056 }
1057
1058 #ifdef CONFIG_PROC_FS
1059 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1060 proc_net_netfilter);
1061 if (!proc_nful)
1062 goto cleanup_subsys;
1063 proc_nful->proc_fops = &nful_file_ops;
1064 #endif
1065 return status;
1066
1067 #ifdef CONFIG_PROC_FS
1068 cleanup_subsys:
1069 nfnetlink_subsys_unregister(&nfulnl_subsys);
1070 #endif
1071 cleanup_netlink_notifier:
1072 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1073 return status;
1074 }
1075
1076 static void __exit nfnetlink_log_fini(void)
1077 {
1078 nf_log_unregister_logger(&nfulnl_logger);
1079 #ifdef CONFIG_PROC_FS
1080 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1081 #endif
1082 nfnetlink_subsys_unregister(&nfulnl_subsys);
1083 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1084 }
1085
1086 MODULE_DESCRIPTION("netfilter userspace logging");
1087 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1088 MODULE_LICENSE("GPL");
1089 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1090
1091 module_init(nfnetlink_log_init);
1092 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support