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Merge ../linux-2.6
[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 NLMSG_GOODSIZE
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 unsigned int n;
318
319 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
320
321 /* alloc skb which should be big enough for a whole multipart
322 * message. WARNING: has to be <= 128k due to slab restrictions */
323
324 n = max(inst_size, pkt_size);
325 skb = alloc_skb(n, GFP_ATOMIC);
326 if (!skb) {
327 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
328 inst_size);
329
330 if (n > pkt_size) {
331 /* try to allocate only as much as we need for current
332 * packet */
333
334 skb = alloc_skb(pkt_size, GFP_ATOMIC);
335 if (!skb)
336 PRINTR("nfnetlink_log: can't even alloc %u "
337 "bytes\n", pkt_size);
338 }
339 }
340
341 return skb;
342 }
343
344 static int
345 __nfulnl_send(struct nfulnl_instance *inst)
346 {
347 int status;
348
349 if (timer_pending(&inst->timer))
350 del_timer(&inst->timer);
351
352 if (inst->qlen > 1)
353 inst->lastnlh->nlmsg_type = NLMSG_DONE;
354
355 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
356 if (status < 0) {
357 UDEBUG("netlink_unicast() failed\n");
358 /* FIXME: statistics */
359 }
360
361 inst->qlen = 0;
362 inst->skb = NULL;
363 inst->lastnlh = NULL;
364
365 return status;
366 }
367
368 static void nfulnl_timer(unsigned long data)
369 {
370 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
371
372 UDEBUG("timer function called, flushing buffer\n");
373
374 spin_lock_bh(&inst->lock);
375 __nfulnl_send(inst);
376 instance_put(inst);
377 spin_unlock_bh(&inst->lock);
378 }
379
380 static inline int
381 __build_packet_message(struct nfulnl_instance *inst,
382 const struct sk_buff *skb,
383 unsigned int data_len,
384 unsigned int pf,
385 unsigned int hooknum,
386 const struct net_device *indev,
387 const struct net_device *outdev,
388 const struct nf_loginfo *li,
389 const char *prefix)
390 {
391 unsigned char *old_tail;
392 struct nfulnl_msg_packet_hdr pmsg;
393 struct nlmsghdr *nlh;
394 struct nfgenmsg *nfmsg;
395 u_int32_t tmp_uint;
396
397 UDEBUG("entered\n");
398
399 old_tail = inst->skb->tail;
400 nlh = NLMSG_PUT(inst->skb, 0, 0,
401 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
402 sizeof(struct nfgenmsg));
403 nfmsg = NLMSG_DATA(nlh);
404 nfmsg->nfgen_family = pf;
405 nfmsg->version = NFNETLINK_V0;
406 nfmsg->res_id = htons(inst->group_num);
407
408 pmsg.hw_protocol = htons(skb->protocol);
409 pmsg.hook = hooknum;
410
411 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
412
413 if (prefix) {
414 int slen = strlen(prefix);
415 if (slen > NFULNL_PREFIXLEN)
416 slen = NFULNL_PREFIXLEN;
417 NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
418 }
419
420 if (indev) {
421 tmp_uint = htonl(indev->ifindex);
422 #ifndef CONFIG_BRIDGE_NETFILTER
423 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
424 &tmp_uint);
425 #else
426 if (pf == PF_BRIDGE) {
427 /* Case 1: outdev is physical input device, we need to
428 * look for bridge group (when called from
429 * netfilter_bridge) */
430 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
431 sizeof(tmp_uint), &tmp_uint);
432 /* this is the bridge group "brX" */
433 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
434 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
435 sizeof(tmp_uint), &tmp_uint);
436 } else {
437 /* Case 2: indev is bridge group, we need to look for
438 * physical device (when called from ipv4) */
439 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
440 sizeof(tmp_uint), &tmp_uint);
441 if (skb->nf_bridge && skb->nf_bridge->physindev) {
442 tmp_uint =
443 htonl(skb->nf_bridge->physindev->ifindex);
444 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
445 sizeof(tmp_uint), &tmp_uint);
446 }
447 }
448 #endif
449 }
450
451 if (outdev) {
452 tmp_uint = htonl(outdev->ifindex);
453 #ifndef CONFIG_BRIDGE_NETFILTER
454 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
455 &tmp_uint);
456 #else
457 if (pf == PF_BRIDGE) {
458 /* Case 1: outdev is physical output device, we need to
459 * look for bridge group (when called from
460 * netfilter_bridge) */
461 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
462 sizeof(tmp_uint), &tmp_uint);
463 /* this is the bridge group "brX" */
464 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
465 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
466 sizeof(tmp_uint), &tmp_uint);
467 } else {
468 /* Case 2: indev is a bridge group, we need to look
469 * for physical device (when called from ipv4) */
470 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
471 sizeof(tmp_uint), &tmp_uint);
472 if (skb->nf_bridge) {
473 tmp_uint =
474 htonl(skb->nf_bridge->physoutdev->ifindex);
475 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
476 sizeof(tmp_uint), &tmp_uint);
477 }
478 }
479 #endif
480 }
481
482 if (skb->nfmark) {
483 tmp_uint = htonl(skb->nfmark);
484 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
485 }
486
487 if (indev && skb->dev && skb->dev->hard_header_parse) {
488 struct nfulnl_msg_packet_hw phw;
489
490 phw.hw_addrlen =
491 skb->dev->hard_header_parse((struct sk_buff *)skb,
492 phw.hw_addr);
493 phw.hw_addrlen = htons(phw.hw_addrlen);
494 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
495 }
496
497 if (skb->tstamp.off_sec) {
498 struct nfulnl_msg_packet_timestamp ts;
499
500 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
501 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
502
503 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
504 }
505
506 /* UID */
507 if (skb->sk) {
508 read_lock_bh(&skb->sk->sk_callback_lock);
509 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
510 u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
511 /* need to unlock here since NFA_PUT may goto */
512 read_unlock_bh(&skb->sk->sk_callback_lock);
513 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
514 } else
515 read_unlock_bh(&skb->sk->sk_callback_lock);
516 }
517
518 if (data_len) {
519 struct nfattr *nfa;
520 int size = NFA_LENGTH(data_len);
521
522 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
523 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
524 goto nlmsg_failure;
525 }
526
527 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
528 nfa->nfa_type = NFULA_PAYLOAD;
529 nfa->nfa_len = size;
530
531 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
532 BUG();
533 }
534
535 nlh->nlmsg_len = inst->skb->tail - old_tail;
536 return 0;
537
538 nlmsg_failure:
539 UDEBUG("nlmsg_failure\n");
540 nfattr_failure:
541 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
542 return -1;
543 }
544
545 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
546
547 static struct nf_loginfo default_loginfo = {
548 .type = NF_LOG_TYPE_ULOG,
549 .u = {
550 .ulog = {
551 .copy_len = 0xffff,
552 .group = 0,
553 .qthreshold = 1,
554 },
555 },
556 };
557
558 /* log handler for internal netfilter logging api */
559 static void
560 nfulnl_log_packet(unsigned int pf,
561 unsigned int hooknum,
562 const struct sk_buff *skb,
563 const struct net_device *in,
564 const struct net_device *out,
565 const struct nf_loginfo *li_user,
566 const char *prefix)
567 {
568 unsigned int size, data_len;
569 struct nfulnl_instance *inst;
570 const struct nf_loginfo *li;
571 unsigned int qthreshold;
572 unsigned int nlbufsiz;
573
574 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
575 li = li_user;
576 else
577 li = &default_loginfo;
578
579 inst = instance_lookup_get(li->u.ulog.group);
580 if (!inst)
581 inst = instance_lookup_get(0);
582 if (!inst) {
583 PRINTR("nfnetlink_log: trying to log packet, "
584 "but no instance for group %u\n", li->u.ulog.group);
585 return;
586 }
587
588 /* all macros expand to constant values at compile time */
589 /* FIXME: do we want to make the size calculation conditional based on
590 * what is actually present? way more branches and checks, but more
591 * memory efficient... */
592 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
593 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
594 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
595 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
596 #ifdef CONFIG_BRIDGE_NETFILTER
597 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
598 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
599 #endif
600 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
601 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
602 + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */
603 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
604 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
605
606 UDEBUG("initial size=%u\n", size);
607
608 spin_lock_bh(&inst->lock);
609
610 qthreshold = inst->qthreshold;
611 /* per-rule qthreshold overrides per-instance */
612 if (qthreshold > li->u.ulog.qthreshold)
613 qthreshold = li->u.ulog.qthreshold;
614
615 switch (inst->copy_mode) {
616 case NFULNL_COPY_META:
617 case NFULNL_COPY_NONE:
618 data_len = 0;
619 break;
620
621 case NFULNL_COPY_PACKET:
622 if (inst->copy_range == 0
623 || inst->copy_range > skb->len)
624 data_len = skb->len;
625 else
626 data_len = inst->copy_range;
627
628 size += NFA_SPACE(data_len);
629 UDEBUG("copy_packet, therefore size now %u\n", size);
630 break;
631
632 default:
633 spin_unlock_bh(&inst->lock);
634 instance_put(inst);
635 return;
636 }
637
638 if (size > inst->nlbufsiz)
639 nlbufsiz = size;
640 else
641 nlbufsiz = inst->nlbufsiz;
642
643 if (!inst->skb) {
644 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
645 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
646 inst->nlbufsiz, size);
647 goto alloc_failure;
648 }
649 } else if (inst->qlen >= qthreshold ||
650 size > skb_tailroom(inst->skb)) {
651 /* either the queue len is too high or we don't have
652 * enough room in the skb left. flush to userspace. */
653 UDEBUG("flushing old skb\n");
654
655 __nfulnl_send(inst);
656
657 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
658 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
659 inst->nlbufsiz, size);
660 goto alloc_failure;
661 }
662 }
663
664 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
665 inst->qlen++;
666
667 __build_packet_message(inst, skb, data_len, pf,
668 hooknum, in, out, li, prefix);
669
670 /* timer_pending always called within inst->lock, so there
671 * is no chance of a race here */
672 if (!timer_pending(&inst->timer)) {
673 instance_get(inst);
674 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
675 add_timer(&inst->timer);
676 }
677 spin_unlock_bh(&inst->lock);
678
679 return;
680
681 alloc_failure:
682 spin_unlock_bh(&inst->lock);
683 instance_put(inst);
684 UDEBUG("error allocating skb\n");
685 /* FIXME: statistics */
686 }
687
688 static int
689 nfulnl_rcv_nl_event(struct notifier_block *this,
690 unsigned long event, void *ptr)
691 {
692 struct netlink_notify *n = ptr;
693
694 if (event == NETLINK_URELEASE &&
695 n->protocol == NETLINK_NETFILTER && n->pid) {
696 int i;
697
698 /* destroy all instances for this pid */
699 write_lock_bh(&instances_lock);
700 for (i = 0; i < INSTANCE_BUCKETS; i++) {
701 struct hlist_node *tmp, *t2;
702 struct nfulnl_instance *inst;
703 struct hlist_head *head = &instance_table[i];
704
705 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
706 UDEBUG("node = %p\n", inst);
707 if (n->pid == inst->peer_pid)
708 __instance_destroy(inst);
709 }
710 }
711 write_unlock_bh(&instances_lock);
712 }
713 return NOTIFY_DONE;
714 }
715
716 static struct notifier_block nfulnl_rtnl_notifier = {
717 .notifier_call = nfulnl_rcv_nl_event,
718 };
719
720 static int
721 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
722 struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
723 {
724 return -ENOTSUPP;
725 }
726
727 static struct nf_logger nfulnl_logger = {
728 .name = "nfnetlink_log",
729 .logfn = &nfulnl_log_packet,
730 .me = THIS_MODULE,
731 };
732
733 static const int nfula_min[NFULA_MAX] = {
734 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
735 [NFULA_MARK-1] = sizeof(u_int32_t),
736 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
737 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
738 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
739 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
740 [NFULA_PAYLOAD-1] = 0,
741 [NFULA_PREFIX-1] = 0,
742 [NFULA_UID-1] = sizeof(u_int32_t),
743 };
744
745 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
746 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
747 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
748 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
749 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
750 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
751 };
752
753 static int
754 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
755 struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
756 {
757 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
758 u_int16_t group_num = ntohs(nfmsg->res_id);
759 struct nfulnl_instance *inst;
760 int ret = 0;
761
762 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
763
764 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
765 UDEBUG("bad attribute size\n");
766 return -EINVAL;
767 }
768
769 inst = instance_lookup_get(group_num);
770 if (nfula[NFULA_CFG_CMD-1]) {
771 u_int8_t pf = nfmsg->nfgen_family;
772 struct nfulnl_msg_config_cmd *cmd;
773 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
774 UDEBUG("found CFG_CMD for\n");
775
776 switch (cmd->command) {
777 case NFULNL_CFG_CMD_BIND:
778 if (inst) {
779 ret = -EBUSY;
780 goto out_put;
781 }
782
783 inst = instance_create(group_num,
784 NETLINK_CB(skb).pid);
785 if (!inst) {
786 ret = -EINVAL;
787 goto out_put;
788 }
789 break;
790 case NFULNL_CFG_CMD_UNBIND:
791 if (!inst) {
792 ret = -ENODEV;
793 goto out_put;
794 }
795
796 if (inst->peer_pid != NETLINK_CB(skb).pid) {
797 ret = -EPERM;
798 goto out_put;
799 }
800
801 instance_destroy(inst);
802 break;
803 case NFULNL_CFG_CMD_PF_BIND:
804 UDEBUG("registering log handler for pf=%u\n", pf);
805 ret = nf_log_register(pf, &nfulnl_logger);
806 break;
807 case NFULNL_CFG_CMD_PF_UNBIND:
808 UDEBUG("unregistering log handler for pf=%u\n", pf);
809 /* This is a bug and a feature. We cannot unregister
810 * other handlers, like nfnetlink_inst can */
811 nf_log_unregister_pf(pf);
812 break;
813 default:
814 ret = -EINVAL;
815 break;
816 }
817 } else {
818 if (!inst) {
819 UDEBUG("no config command, and no instance for "
820 "group=%u pid=%u =>ENOENT\n",
821 group_num, NETLINK_CB(skb).pid);
822 ret = -ENOENT;
823 goto out_put;
824 }
825
826 if (inst->peer_pid != NETLINK_CB(skb).pid) {
827 UDEBUG("no config command, and wrong pid\n");
828 ret = -EPERM;
829 goto out_put;
830 }
831 }
832
833 if (nfula[NFULA_CFG_MODE-1]) {
834 struct nfulnl_msg_config_mode *params;
835 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
836
837 nfulnl_set_mode(inst, params->copy_mode,
838 ntohs(params->copy_range));
839 }
840
841 if (nfula[NFULA_CFG_TIMEOUT-1]) {
842 u_int32_t timeout =
843 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
844
845 nfulnl_set_timeout(inst, ntohl(timeout));
846 }
847
848 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
849 u_int32_t nlbufsiz =
850 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
851
852 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
853 }
854
855 if (nfula[NFULA_CFG_QTHRESH-1]) {
856 u_int32_t qthresh =
857 *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
858
859 nfulnl_set_qthresh(inst, ntohl(qthresh));
860 }
861
862 out_put:
863 instance_put(inst);
864 return ret;
865 }
866
867 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
868 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
869 .attr_count = NFULA_MAX, },
870 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
871 .attr_count = NFULA_CFG_MAX, },
872 };
873
874 static struct nfnetlink_subsystem nfulnl_subsys = {
875 .name = "log",
876 .subsys_id = NFNL_SUBSYS_ULOG,
877 .cb_count = NFULNL_MSG_MAX,
878 .cb = nfulnl_cb,
879 };
880
881 #ifdef CONFIG_PROC_FS
882 struct iter_state {
883 unsigned int bucket;
884 };
885
886 static struct hlist_node *get_first(struct seq_file *seq)
887 {
888 struct iter_state *st = seq->private;
889
890 if (!st)
891 return NULL;
892
893 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
894 if (!hlist_empty(&instance_table[st->bucket]))
895 return instance_table[st->bucket].first;
896 }
897 return NULL;
898 }
899
900 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
901 {
902 struct iter_state *st = seq->private;
903
904 h = h->next;
905 while (!h) {
906 if (++st->bucket >= INSTANCE_BUCKETS)
907 return NULL;
908
909 h = instance_table[st->bucket].first;
910 }
911 return h;
912 }
913
914 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
915 {
916 struct hlist_node *head;
917 head = get_first(seq);
918
919 if (head)
920 while (pos && (head = get_next(seq, head)))
921 pos--;
922 return pos ? NULL : head;
923 }
924
925 static void *seq_start(struct seq_file *seq, loff_t *pos)
926 {
927 read_lock_bh(&instances_lock);
928 return get_idx(seq, *pos);
929 }
930
931 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
932 {
933 (*pos)++;
934 return get_next(s, v);
935 }
936
937 static void seq_stop(struct seq_file *s, void *v)
938 {
939 read_unlock_bh(&instances_lock);
940 }
941
942 static int seq_show(struct seq_file *s, void *v)
943 {
944 const struct nfulnl_instance *inst = v;
945
946 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
947 inst->group_num,
948 inst->peer_pid, inst->qlen,
949 inst->copy_mode, inst->copy_range,
950 inst->flushtimeout, atomic_read(&inst->use));
951 }
952
953 static struct seq_operations nful_seq_ops = {
954 .start = seq_start,
955 .next = seq_next,
956 .stop = seq_stop,
957 .show = seq_show,
958 };
959
960 static int nful_open(struct inode *inode, struct file *file)
961 {
962 struct seq_file *seq;
963 struct iter_state *is;
964 int ret;
965
966 is = kzalloc(sizeof(*is), GFP_KERNEL);
967 if (!is)
968 return -ENOMEM;
969 ret = seq_open(file, &nful_seq_ops);
970 if (ret < 0)
971 goto out_free;
972 seq = file->private_data;
973 seq->private = is;
974 return ret;
975 out_free:
976 kfree(is);
977 return ret;
978 }
979
980 static struct file_operations nful_file_ops = {
981 .owner = THIS_MODULE,
982 .open = nful_open,
983 .read = seq_read,
984 .llseek = seq_lseek,
985 .release = seq_release_private,
986 };
987
988 #endif /* PROC_FS */
989
990 static int
991 init_or_cleanup(int init)
992 {
993 int i, status = -ENOMEM;
994 #ifdef CONFIG_PROC_FS
995 struct proc_dir_entry *proc_nful;
996 #endif
997
998 if (!init)
999 goto cleanup;
1000
1001 for (i = 0; i < INSTANCE_BUCKETS; i++)
1002 INIT_HLIST_HEAD(&instance_table[i]);
1003
1004 /* it's not really all that important to have a random value, so
1005 * we can do this from the init function, even if there hasn't
1006 * been that much entropy yet */
1007 get_random_bytes(&hash_init, sizeof(hash_init));
1008
1009 netlink_register_notifier(&nfulnl_rtnl_notifier);
1010 status = nfnetlink_subsys_register(&nfulnl_subsys);
1011 if (status < 0) {
1012 printk(KERN_ERR "log: failed to create netlink socket\n");
1013 goto cleanup_netlink_notifier;
1014 }
1015
1016 #ifdef CONFIG_PROC_FS
1017 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1018 proc_net_netfilter);
1019 if (!proc_nful)
1020 goto cleanup_subsys;
1021 proc_nful->proc_fops = &nful_file_ops;
1022 #endif
1023
1024 return status;
1025
1026 cleanup:
1027 nf_log_unregister_logger(&nfulnl_logger);
1028 #ifdef CONFIG_PROC_FS
1029 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1030 cleanup_subsys:
1031 #endif
1032 nfnetlink_subsys_unregister(&nfulnl_subsys);
1033 cleanup_netlink_notifier:
1034 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1035 return status;
1036 }
1037
1038 static int __init init(void)
1039 {
1040
1041 return init_or_cleanup(1);
1042 }
1043
1044 static void __exit fini(void)
1045 {
1046 init_or_cleanup(0);
1047 }
1048
1049 MODULE_DESCRIPTION("netfilter userspace logging");
1050 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1051 MODULE_LICENSE("GPL");
1052 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1053
1054 module_init(init);
1055 module_exit(fini);
Linux kernel - Deliverables
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