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Merge with Linus' kernel.
[deliverable/linux.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 */
15 #include <linux/module.h>
16 #include <linux/skbuff.h>
17 #include <linux/init.h>
18 #include <linux/ip.h>
19 #include <linux/ipv6.h>
20 #include <linux/netdevice.h>
21 #include <linux/netfilter.h>
22 #include <linux/netlink.h>
23 #include <linux/netfilter/nfnetlink.h>
24 #include <linux/netfilter/nfnetlink_log.h>
25 #include <linux/spinlock.h>
26 #include <linux/sysctl.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/list.h>
30 #include <linux/jhash.h>
31 #include <linux/random.h>
32 #include <net/sock.h>
33
34 #include <asm/atomic.h>
35
36 #ifdef CONFIG_BRIDGE_NETFILTER
37 #include "../bridge/br_private.h"
38 #endif
39
40 #define NFULNL_NLBUFSIZ_DEFAULT 4096
41 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
42 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
43
44 #define PRINTR(x, args...) do { if (net_ratelimit()) \
45 printk(x, ## args); } while (0);
46
47 #if 0
48 #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
49 __FILE__, __LINE__, __FUNCTION__, \
50 ## args)
51 #else
52 #define UDEBUG(x, ...)
53 #endif
54
55 struct nfulnl_instance {
56 struct hlist_node hlist; /* global list of instances */
57 spinlock_t lock;
58 atomic_t use; /* use count */
59
60 unsigned int qlen; /* number of nlmsgs in skb */
61 struct sk_buff *skb; /* pre-allocatd skb */
62 struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
63 struct timer_list timer;
64 int peer_pid; /* PID of the peer process */
65
66 /* configurable parameters */
67 unsigned int flushtimeout; /* timeout until queue flush */
68 unsigned int nlbufsiz; /* netlink buffer allocation size */
69 unsigned int qthreshold; /* threshold of the queue */
70 u_int32_t copy_range;
71 u_int16_t group_num; /* number of this queue */
72 u_int8_t copy_mode;
73 };
74
75 static DEFINE_RWLOCK(instances_lock);
76
77 #define INSTANCE_BUCKETS 16
78 static struct hlist_head instance_table[INSTANCE_BUCKETS];
79 static unsigned int hash_init;
80
81 static inline u_int8_t instance_hashfn(u_int16_t group_num)
82 {
83 return ((group_num & 0xff) % INSTANCE_BUCKETS);
84 }
85
86 static struct nfulnl_instance *
87 __instance_lookup(u_int16_t group_num)
88 {
89 struct hlist_head *head;
90 struct hlist_node *pos;
91 struct nfulnl_instance *inst;
92
93 UDEBUG("entering (group_num=%u)\n", group_num);
94
95 head = &instance_table[instance_hashfn(group_num)];
96 hlist_for_each_entry(inst, pos, head, hlist) {
97 if (inst->group_num == group_num)
98 return inst;
99 }
100 return NULL;
101 }
102
103 static inline void
104 instance_get(struct nfulnl_instance *inst)
105 {
106 atomic_inc(&inst->use);
107 }
108
109 static struct nfulnl_instance *
110 instance_lookup_get(u_int16_t group_num)
111 {
112 struct nfulnl_instance *inst;
113
114 read_lock_bh(&instances_lock);
115 inst = __instance_lookup(group_num);
116 if (inst)
117 instance_get(inst);
118 read_unlock_bh(&instances_lock);
119
120 return inst;
121 }
122
123 static void
124 instance_put(struct nfulnl_instance *inst)
125 {
126 if (inst && atomic_dec_and_test(&inst->use)) {
127 UDEBUG("kfree(inst=%p)\n", inst);
128 kfree(inst);
129 }
130 }
131
132 static void nfulnl_timer(unsigned long data);
133
134 static struct nfulnl_instance *
135 instance_create(u_int16_t group_num, int pid)
136 {
137 struct nfulnl_instance *inst;
138
139 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
140 pid);
141
142 write_lock_bh(&instances_lock);
143 if (__instance_lookup(group_num)) {
144 inst = NULL;
145 UDEBUG("aborting, instance already exists\n");
146 goto out_unlock;
147 }
148
149 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
150 if (!inst)
151 goto out_unlock;
152
153 INIT_HLIST_NODE(&inst->hlist);
154 spin_lock_init(&inst->lock);
155 /* needs to be two, since we _put() after creation */
156 atomic_set(&inst->use, 2);
157
158 init_timer(&inst->timer);
159 inst->timer.function = nfulnl_timer;
160 inst->timer.data = (unsigned long)inst;
161 /* don't start timer yet. (re)start it with every packet */
162
163 inst->peer_pid = pid;
164 inst->group_num = group_num;
165
166 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
167 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
168 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
169 inst->copy_mode = NFULNL_COPY_PACKET;
170 inst->copy_range = 0xffff;
171
172 if (!try_module_get(THIS_MODULE))
173 goto out_free;
174
175 hlist_add_head(&inst->hlist,
176 &instance_table[instance_hashfn(group_num)]);
177
178 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
179 inst->hlist.next);
180
181 write_unlock_bh(&instances_lock);
182
183 return inst;
184
185 out_free:
186 instance_put(inst);
187 out_unlock:
188 write_unlock_bh(&instances_lock);
189 return NULL;
190 }
191
192 static int __nfulnl_send(struct nfulnl_instance *inst);
193
194 static void
195 _instance_destroy2(struct nfulnl_instance *inst, int lock)
196 {
197 /* first pull it out of the global list */
198 if (lock)
199 write_lock_bh(&instances_lock);
200
201 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
202 inst, inst->group_num);
203
204 hlist_del(&inst->hlist);
205
206 if (lock)
207 write_unlock_bh(&instances_lock);
208
209 /* then flush all pending packets from skb */
210
211 spin_lock_bh(&inst->lock);
212 if (inst->skb) {
213 if (inst->qlen)
214 __nfulnl_send(inst);
215 if (inst->skb) {
216 kfree_skb(inst->skb);
217 inst->skb = NULL;
218 }
219 }
220 spin_unlock_bh(&inst->lock);
221
222 /* and finally put the refcount */
223 instance_put(inst);
224
225 module_put(THIS_MODULE);
226 }
227
228 static inline void
229 __instance_destroy(struct nfulnl_instance *inst)
230 {
231 _instance_destroy2(inst, 0);
232 }
233
234 static inline void
235 instance_destroy(struct nfulnl_instance *inst)
236 {
237 _instance_destroy2(inst, 1);
238 }
239
240 static int
241 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
242 unsigned int range)
243 {
244 int status = 0;
245
246 spin_lock_bh(&inst->lock);
247
248 switch (mode) {
249 case NFULNL_COPY_NONE:
250 case NFULNL_COPY_META:
251 inst->copy_mode = mode;
252 inst->copy_range = 0;
253 break;
254
255 case NFULNL_COPY_PACKET:
256 inst->copy_mode = mode;
257 /* we're using struct nfattr which has 16bit nfa_len */
258 if (range > 0xffff)
259 inst->copy_range = 0xffff;
260 else
261 inst->copy_range = range;
262 break;
263
264 default:
265 status = -EINVAL;
266 break;
267 }
268
269 spin_unlock_bh(&inst->lock);
270
271 return status;
272 }
273
274 static int
275 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
276 {
277 int status;
278
279 spin_lock_bh(&inst->lock);
280 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
281 status = -ERANGE;
282 else if (nlbufsiz > 131072)
283 status = -ERANGE;
284 else {
285 inst->nlbufsiz = nlbufsiz;
286 status = 0;
287 }
288 spin_unlock_bh(&inst->lock);
289
290 return status;
291 }
292
293 static int
294 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
295 {
296 spin_lock_bh(&inst->lock);
297 inst->flushtimeout = timeout;
298 spin_unlock_bh(&inst->lock);
299
300 return 0;
301 }
302
303 static int
304 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
305 {
306 spin_lock_bh(&inst->lock);
307 inst->qthreshold = qthresh;
308 spin_unlock_bh(&inst->lock);
309
310 return 0;
311 }
312
313 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
314 unsigned int pkt_size)
315 {
316 struct sk_buff *skb;
317
318 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
319
320 /* alloc skb which should be big enough for a whole multipart
321 * message. WARNING: has to be <= 128k due to slab restrictions */
322
323 skb = alloc_skb(inst_size, GFP_ATOMIC);
324 if (!skb) {
325 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
326 inst_size);
327
328 /* try to allocate only as much as we need for current
329 * packet */
330
331 skb = alloc_skb(pkt_size, GFP_ATOMIC);
332 if (!skb)
333 PRINTR("nfnetlink_log: can't even alloc %u bytes\n",
334 pkt_size);
335 }
336
337 return skb;
338 }
339
340 static int
341 __nfulnl_send(struct nfulnl_instance *inst)
342 {
343 int status;
344
345 if (timer_pending(&inst->timer))
346 del_timer(&inst->timer);
347
348 if (inst->qlen > 1)
349 inst->lastnlh->nlmsg_type = NLMSG_DONE;
350
351 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
352 if (status < 0) {
353 UDEBUG("netlink_unicast() failed\n");
354 /* FIXME: statistics */
355 }
356
357 inst->qlen = 0;
358 inst->skb = NULL;
359 inst->lastnlh = NULL;
360
361 return status;
362 }
363
364 static void nfulnl_timer(unsigned long data)
365 {
366 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
367
368 UDEBUG("timer function called, flushing buffer\n");
369
370 spin_lock_bh(&inst->lock);
371 __nfulnl_send(inst);
372 instance_put(inst);
373 spin_unlock_bh(&inst->lock);
374 }
375
376 static inline int
377 __build_packet_message(struct nfulnl_instance *inst,
378 const struct sk_buff *skb,
379 unsigned int data_len,
380 unsigned int pf,
381 unsigned int hooknum,
382 const struct net_device *indev,
383 const struct net_device *outdev,
384 const struct nf_loginfo *li,
385 const char *prefix)
386 {
387 unsigned char *old_tail;
388 struct nfulnl_msg_packet_hdr pmsg;
389 struct nlmsghdr *nlh;
390 struct nfgenmsg *nfmsg;
391 u_int32_t tmp_uint;
392
393 UDEBUG("entered\n");
394
395 old_tail = inst->skb->tail;
396 nlh = NLMSG_PUT(inst->skb, 0, 0,
397 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
398 sizeof(struct nfgenmsg));
399 nfmsg = NLMSG_DATA(nlh);
400 nfmsg->nfgen_family = pf;
401 nfmsg->version = NFNETLINK_V0;
402 nfmsg->res_id = htons(inst->group_num);
403
404 pmsg.hw_protocol = htons(skb->protocol);
405 pmsg.hook = hooknum;
406
407 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
408
409 if (prefix) {
410 int slen = strlen(prefix);
411 if (slen > NFULNL_PREFIXLEN)
412 slen = NFULNL_PREFIXLEN;
413 NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
414 }
415
416 if (indev) {
417 tmp_uint = htonl(indev->ifindex);
418 #ifndef CONFIG_BRIDGE_NETFILTER
419 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
420 &tmp_uint);
421 #else
422 if (pf == PF_BRIDGE) {
423 /* Case 1: outdev is physical input device, we need to
424 * look for bridge group (when called from
425 * netfilter_bridge) */
426 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
427 sizeof(tmp_uint), &tmp_uint);
428 /* this is the bridge group "brX" */
429 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
430 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
431 sizeof(tmp_uint), &tmp_uint);
432 } else {
433 /* Case 2: indev is bridge group, we need to look for
434 * physical device (when called from ipv4) */
435 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
436 sizeof(tmp_uint), &tmp_uint);
437 if (skb->nf_bridge && skb->nf_bridge->physindev) {
438 tmp_uint =
439 htonl(skb->nf_bridge->physindev->ifindex);
440 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
441 sizeof(tmp_uint), &tmp_uint);
442 }
443 }
444 #endif
445 }
446
447 if (outdev) {
448 tmp_uint = htonl(outdev->ifindex);
449 #ifndef CONFIG_BRIDGE_NETFILTER
450 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
451 &tmp_uint);
452 #else
453 if (pf == PF_BRIDGE) {
454 /* Case 1: outdev is physical output device, we need to
455 * look for bridge group (when called from
456 * netfilter_bridge) */
457 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
458 sizeof(tmp_uint), &tmp_uint);
459 /* this is the bridge group "brX" */
460 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
461 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
462 sizeof(tmp_uint), &tmp_uint);
463 } else {
464 /* Case 2: indev is a bridge group, we need to look
465 * for physical device (when called from ipv4) */
466 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
467 sizeof(tmp_uint), &tmp_uint);
468 if (skb->nf_bridge) {
469 tmp_uint =
470 htonl(skb->nf_bridge->physoutdev->ifindex);
471 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
472 sizeof(tmp_uint), &tmp_uint);
473 }
474 }
475 #endif
476 }
477
478 if (skb->nfmark) {
479 tmp_uint = htonl(skb->nfmark);
480 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
481 }
482
483 if (indev && skb->dev && skb->dev->hard_header_parse) {
484 struct nfulnl_msg_packet_hw phw;
485
486 phw.hw_addrlen =
487 skb->dev->hard_header_parse((struct sk_buff *)skb,
488 phw.hw_addr);
489 phw.hw_addrlen = htons(phw.hw_addrlen);
490 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
491 }
492
493 if (skb->tstamp.off_sec) {
494 struct nfulnl_msg_packet_timestamp ts;
495
496 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
497 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
498
499 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
500 }
501
502 /* UID */
503 if (skb->sk) {
504 read_lock_bh(&skb->sk->sk_callback_lock);
505 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
506 u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
507 /* need to unlock here since NFA_PUT may goto */
508 read_unlock_bh(&skb->sk->sk_callback_lock);
509 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
510 } else
511 read_unlock_bh(&skb->sk->sk_callback_lock);
512 }
513
514 if (data_len) {
515 struct nfattr *nfa;
516 int size = NFA_LENGTH(data_len);
517
518 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
519 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
520 goto nlmsg_failure;
521 }
522
523 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
524 nfa->nfa_type = NFULA_PAYLOAD;
525 nfa->nfa_len = size;
526
527 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
528 BUG();
529 }
530
531 nlh->nlmsg_len = inst->skb->tail - old_tail;
532 return 0;
533
534 nlmsg_failure:
535 UDEBUG("nlmsg_failure\n");
536 nfattr_failure:
537 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
538 return -1;
539 }
540
541 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
542
543 static struct nf_loginfo default_loginfo = {
544 .type = NF_LOG_TYPE_ULOG,
545 .u = {
546 .ulog = {
547 .copy_len = 0xffff,
548 .group = 0,
549 .qthreshold = 1,
550 },
551 },
552 };
553
554 /* log handler for internal netfilter logging api */
555 static void
556 nfulnl_log_packet(unsigned int pf,
557 unsigned int hooknum,
558 const struct sk_buff *skb,
559 const struct net_device *in,
560 const struct net_device *out,
561 const struct nf_loginfo *li_user,
562 const char *prefix)
563 {
564 unsigned int size, data_len;
565 struct nfulnl_instance *inst;
566 const struct nf_loginfo *li;
567 unsigned int qthreshold;
568 unsigned int nlbufsiz;
569
570 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
571 li = li_user;
572 else
573 li = &default_loginfo;
574
575 inst = instance_lookup_get(li->u.ulog.group);
576 if (!inst)
577 inst = instance_lookup_get(0);
578 if (!inst) {
579 PRINTR("nfnetlink_log: trying to log packet, "
580 "but no instance for group %u\n", li->u.ulog.group);
581 return;
582 }
583
584 /* all macros expand to constant values at compile time */
585 /* FIXME: do we want to make the size calculation conditional based on
586 * what is actually present? way more branches and checks, but more
587 * memory efficient... */
588 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
589 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
590 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
591 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
592 #ifdef CONFIG_BRIDGE_NETFILTER
593 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
594 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
595 #endif
596 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
597 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
598 + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */
599 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
600 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
601
602 UDEBUG("initial size=%u\n", size);
603
604 spin_lock_bh(&inst->lock);
605
606 qthreshold = inst->qthreshold;
607 /* per-rule qthreshold overrides per-instance */
608 if (qthreshold > li->u.ulog.qthreshold)
609 qthreshold = li->u.ulog.qthreshold;
610
611 switch (inst->copy_mode) {
612 case NFULNL_COPY_META:
613 case NFULNL_COPY_NONE:
614 data_len = 0;
615 break;
616
617 case NFULNL_COPY_PACKET:
618 if (inst->copy_range == 0
619 || inst->copy_range > skb->len)
620 data_len = skb->len;
621 else
622 data_len = inst->copy_range;
623
624 size += NFA_SPACE(data_len);
625 UDEBUG("copy_packet, therefore size now %u\n", size);
626 break;
627
628 default:
629 spin_unlock_bh(&inst->lock);
630 instance_put(inst);
631 return;
632 }
633
634 if (size > inst->nlbufsiz)
635 nlbufsiz = size;
636 else
637 nlbufsiz = inst->nlbufsiz;
638
639 if (!inst->skb) {
640 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
641 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
642 inst->nlbufsiz, size);
643 goto alloc_failure;
644 }
645 } else if (inst->qlen >= qthreshold ||
646 size > skb_tailroom(inst->skb)) {
647 /* either the queue len is too high or we don't have
648 * enough room in the skb left. flush to userspace. */
649 UDEBUG("flushing old skb\n");
650
651 __nfulnl_send(inst);
652
653 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
654 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
655 inst->nlbufsiz, size);
656 goto alloc_failure;
657 }
658 }
659
660 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
661 inst->qlen++;
662
663 __build_packet_message(inst, skb, data_len, pf,
664 hooknum, in, out, li, prefix);
665
666 /* timer_pending always called within inst->lock, so there
667 * is no chance of a race here */
668 if (!timer_pending(&inst->timer)) {
669 instance_get(inst);
670 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
671 add_timer(&inst->timer);
672 }
673 spin_unlock_bh(&inst->lock);
674
675 return;
676
677 alloc_failure:
678 spin_unlock_bh(&inst->lock);
679 instance_put(inst);
680 UDEBUG("error allocating skb\n");
681 /* FIXME: statistics */
682 }
683
684 static int
685 nfulnl_rcv_nl_event(struct notifier_block *this,
686 unsigned long event, void *ptr)
687 {
688 struct netlink_notify *n = ptr;
689
690 if (event == NETLINK_URELEASE &&
691 n->protocol == NETLINK_NETFILTER && n->pid) {
692 int i;
693
694 /* destroy all instances for this pid */
695 write_lock_bh(&instances_lock);
696 for (i = 0; i < INSTANCE_BUCKETS; i++) {
697 struct hlist_node *tmp, *t2;
698 struct nfulnl_instance *inst;
699 struct hlist_head *head = &instance_table[i];
700
701 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
702 UDEBUG("node = %p\n", inst);
703 if (n->pid == inst->peer_pid)
704 __instance_destroy(inst);
705 }
706 }
707 write_unlock_bh(&instances_lock);
708 }
709 return NOTIFY_DONE;
710 }
711
712 static struct notifier_block nfulnl_rtnl_notifier = {
713 .notifier_call = nfulnl_rcv_nl_event,
714 };
715
716 static int
717 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
718 struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
719 {
720 return -ENOTSUPP;
721 }
722
723 static struct nf_logger nfulnl_logger = {
724 .name = "nfnetlink_log",
725 .logfn = &nfulnl_log_packet,
726 .me = THIS_MODULE,
727 };
728
729 static const int nfula_min[NFULA_MAX] = {
730 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
731 [NFULA_MARK-1] = sizeof(u_int32_t),
732 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
733 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
734 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
735 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
736 [NFULA_PAYLOAD-1] = 0,
737 [NFULA_PREFIX-1] = 0,
738 [NFULA_UID-1] = sizeof(u_int32_t),
739 };
740
741 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
742 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
743 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
744 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
745 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
746 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
747 };
748
749 static int
750 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
751 struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
752 {
753 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
754 u_int16_t group_num = ntohs(nfmsg->res_id);
755 struct nfulnl_instance *inst;
756 int ret = 0;
757
758 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
759
760 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
761 UDEBUG("bad attribute size\n");
762 return -EINVAL;
763 }
764
765 inst = instance_lookup_get(group_num);
766 if (nfula[NFULA_CFG_CMD-1]) {
767 u_int8_t pf = nfmsg->nfgen_family;
768 struct nfulnl_msg_config_cmd *cmd;
769 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
770 UDEBUG("found CFG_CMD for\n");
771
772 switch (cmd->command) {
773 case NFULNL_CFG_CMD_BIND:
774 if (inst) {
775 ret = -EBUSY;
776 goto out_put;
777 }
778
779 inst = instance_create(group_num,
780 NETLINK_CB(skb).pid);
781 if (!inst) {
782 ret = -EINVAL;
783 goto out_put;
784 }
785 break;
786 case NFULNL_CFG_CMD_UNBIND:
787 if (!inst) {
788 ret = -ENODEV;
789 goto out_put;
790 }
791
792 if (inst->peer_pid != NETLINK_CB(skb).pid) {
793 ret = -EPERM;
794 goto out_put;
795 }
796
797 instance_destroy(inst);
798 break;
799 case NFULNL_CFG_CMD_PF_BIND:
800 UDEBUG("registering log handler for pf=%u\n", pf);
801 ret = nf_log_register(pf, &nfulnl_logger);
802 break;
803 case NFULNL_CFG_CMD_PF_UNBIND:
804 UDEBUG("unregistering log handler for pf=%u\n", pf);
805 /* This is a bug and a feature. We cannot unregister
806 * other handlers, like nfnetlink_inst can */
807 nf_log_unregister_pf(pf);
808 break;
809 default:
810 ret = -EINVAL;
811 break;
812 }
813 } else {
814 if (!inst) {
815 UDEBUG("no config command, and no instance for "
816 "group=%u pid=%u =>ENOENT\n",
817 group_num, NETLINK_CB(skb).pid);
818 ret = -ENOENT;
819 goto out_put;
820 }
821
822 if (inst->peer_pid != NETLINK_CB(skb).pid) {
823 UDEBUG("no config command, and wrong pid\n");
824 ret = -EPERM;
825 goto out_put;
826 }
827 }
828
829 if (nfula[NFULA_CFG_MODE-1]) {
830 struct nfulnl_msg_config_mode *params;
831 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
832
833 nfulnl_set_mode(inst, params->copy_mode,
834 ntohs(params->copy_range));
835 }
836
837 if (nfula[NFULA_CFG_TIMEOUT-1]) {
838 u_int32_t timeout =
839 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
840
841 nfulnl_set_timeout(inst, ntohl(timeout));
842 }
843
844 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
845 u_int32_t nlbufsiz =
846 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
847
848 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
849 }
850
851 if (nfula[NFULA_CFG_QTHRESH-1]) {
852 u_int32_t qthresh =
853 *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
854
855 nfulnl_set_qthresh(inst, ntohl(qthresh));
856 }
857
858 out_put:
859 instance_put(inst);
860 return ret;
861 }
862
863 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
864 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
865 .attr_count = NFULA_MAX, },
866 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
867 .attr_count = NFULA_CFG_MAX, },
868 };
869
870 static struct nfnetlink_subsystem nfulnl_subsys = {
871 .name = "log",
872 .subsys_id = NFNL_SUBSYS_ULOG,
873 .cb_count = NFULNL_MSG_MAX,
874 .cb = nfulnl_cb,
875 };
876
877 #ifdef CONFIG_PROC_FS
878 struct iter_state {
879 unsigned int bucket;
880 };
881
882 static struct hlist_node *get_first(struct seq_file *seq)
883 {
884 struct iter_state *st = seq->private;
885
886 if (!st)
887 return NULL;
888
889 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
890 if (!hlist_empty(&instance_table[st->bucket]))
891 return instance_table[st->bucket].first;
892 }
893 return NULL;
894 }
895
896 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
897 {
898 struct iter_state *st = seq->private;
899
900 h = h->next;
901 while (!h) {
902 if (++st->bucket >= INSTANCE_BUCKETS)
903 return NULL;
904
905 h = instance_table[st->bucket].first;
906 }
907 return h;
908 }
909
910 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
911 {
912 struct hlist_node *head;
913 head = get_first(seq);
914
915 if (head)
916 while (pos && (head = get_next(seq, head)))
917 pos--;
918 return pos ? NULL : head;
919 }
920
921 static void *seq_start(struct seq_file *seq, loff_t *pos)
922 {
923 read_lock_bh(&instances_lock);
924 return get_idx(seq, *pos);
925 }
926
927 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
928 {
929 (*pos)++;
930 return get_next(s, v);
931 }
932
933 static void seq_stop(struct seq_file *s, void *v)
934 {
935 read_unlock_bh(&instances_lock);
936 }
937
938 static int seq_show(struct seq_file *s, void *v)
939 {
940 const struct nfulnl_instance *inst = v;
941
942 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
943 inst->group_num,
944 inst->peer_pid, inst->qlen,
945 inst->copy_mode, inst->copy_range,
946 inst->flushtimeout, atomic_read(&inst->use));
947 }
948
949 static struct seq_operations nful_seq_ops = {
950 .start = seq_start,
951 .next = seq_next,
952 .stop = seq_stop,
953 .show = seq_show,
954 };
955
956 static int nful_open(struct inode *inode, struct file *file)
957 {
958 struct seq_file *seq;
959 struct iter_state *is;
960 int ret;
961
962 is = kzalloc(sizeof(*is), GFP_KERNEL);
963 if (!is)
964 return -ENOMEM;
965 ret = seq_open(file, &nful_seq_ops);
966 if (ret < 0)
967 goto out_free;
968 seq = file->private_data;
969 seq->private = is;
970 return ret;
971 out_free:
972 kfree(is);
973 return ret;
974 }
975
976 static struct file_operations nful_file_ops = {
977 .owner = THIS_MODULE,
978 .open = nful_open,
979 .read = seq_read,
980 .llseek = seq_lseek,
981 .release = seq_release_private,
982 };
983
984 #endif /* PROC_FS */
985
986 static int
987 init_or_cleanup(int init)
988 {
989 int i, status = -ENOMEM;
990 #ifdef CONFIG_PROC_FS
991 struct proc_dir_entry *proc_nful;
992 #endif
993
994 if (!init)
995 goto cleanup;
996
997 for (i = 0; i < INSTANCE_BUCKETS; i++)
998 INIT_HLIST_HEAD(&instance_table[i]);
999
1000 /* it's not really all that important to have a random value, so
1001 * we can do this from the init function, even if there hasn't
1002 * been that much entropy yet */
1003 get_random_bytes(&hash_init, sizeof(hash_init));
1004
1005 netlink_register_notifier(&nfulnl_rtnl_notifier);
1006 status = nfnetlink_subsys_register(&nfulnl_subsys);
1007 if (status < 0) {
1008 printk(KERN_ERR "log: failed to create netlink socket\n");
1009 goto cleanup_netlink_notifier;
1010 }
1011
1012 #ifdef CONFIG_PROC_FS
1013 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1014 proc_net_netfilter);
1015 if (!proc_nful)
1016 goto cleanup_subsys;
1017 proc_nful->proc_fops = &nful_file_ops;
1018 #endif
1019
1020 return status;
1021
1022 cleanup:
1023 nf_log_unregister_logger(&nfulnl_logger);
1024 #ifdef CONFIG_PROC_FS
1025 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1026 cleanup_subsys:
1027 #endif
1028 nfnetlink_subsys_unregister(&nfulnl_subsys);
1029 cleanup_netlink_notifier:
1030 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1031 return status;
1032 }
1033
1034 static int __init init(void)
1035 {
1036
1037 return init_or_cleanup(1);
1038 }
1039
1040 static void __exit fini(void)
1041 {
1042 init_or_cleanup(0);
1043 }
1044
1045 MODULE_DESCRIPTION("netfilter userspace logging");
1046 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1047 MODULE_LICENSE("GPL");
1048 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1049
1050 module_init(init);
1051 module_exit(fini);
Linux kernel - Deliverables
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