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[NETFILTER]: Fix double free after netlink_unicast() in ctnetlink
[net-next-2.6.git] / net / netfilter / nfnetlink_log.c
CommitLineData
0597f268
HW		 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
fbcd923c
HW		 36#ifdef CONFIG_BRIDGE_NETFILTER
37#include "../bridge/br_private.h"
38#endif
39
0597f268
HW		 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
55struct 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
75static DEFINE_RWLOCK(instances_lock);
76
77#define INSTANCE_BUCKETS 16
78static struct hlist_head instance_table[INSTANCE_BUCKETS];
79static unsigned int hash_init;
80
81static inline u_int8_t instance_hashfn(u_int16_t group_num)
82{
83 return ((group_num & 0xff) % INSTANCE_BUCKETS);
84}
85
86static 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
103static inline void
104instance_get(struct nfulnl_instance *inst)
105{
106 atomic_inc(&inst->use);
107}
108
109static struct nfulnl_instance *
110instance_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
123static void
124instance_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
132static void nfulnl_timer(unsigned long data);
133
134static struct nfulnl_instance *
135instance_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 = kmalloc(sizeof(*inst), GFP_ATOMIC);
150 if (!inst)
151 goto out_unlock;
152
153 memset(inst, 0, sizeof(*inst));
154 INIT_HLIST_NODE(&inst->hlist);
155 inst->lock = SPIN_LOCK_UNLOCKED;
156 /* needs to be two, since we _put() after creation */
157 atomic_set(&inst->use, 2);
158
159 init_timer(&inst->timer);
160 inst->timer.function = nfulnl_timer;
161 inst->timer.data = (unsigned long)inst;
162 /* don't start timer yet. (re)start it with every packet */
163
164 inst->peer_pid = pid;
165 inst->group_num = group_num;
166
167 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
168 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
169 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
170 inst->copy_mode = NFULNL_COPY_PACKET;
171 inst->copy_range = 0xffff;
172
173 if (!try_module_get(THIS_MODULE))
174 goto out_free;
175
176 hlist_add_head(&inst->hlist,
177 &instance_table[instance_hashfn(group_num)]);
178
179 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
180 inst->hlist.next);
181
182 write_unlock_bh(&instances_lock);
183
184 return inst;
185
186out_free:
187 instance_put(inst);
188out_unlock:
189 write_unlock_bh(&instances_lock);
190 return NULL;
191}
192
193static int __nfulnl_send(struct nfulnl_instance *inst);
194
195static void
196_instance_destroy2(struct nfulnl_instance *inst, int lock)
197{
198 /* first pull it out of the global list */
199 if (lock)
200 write_lock_bh(&instances_lock);
201
202 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
203 inst, inst->group_num);
204
205 hlist_del(&inst->hlist);
206
207 if (lock)
208 write_unlock_bh(&instances_lock);
209
210 /* then flush all pending packets from skb */
211
212 spin_lock_bh(&inst->lock);
213 if (inst->skb) {
214 if (inst->qlen)
215 __nfulnl_send(inst);
216 if (inst->skb) {
217 kfree_skb(inst->skb);
218 inst->skb = NULL;
219 }
220 }
221 spin_unlock_bh(&inst->lock);
222
223 /* and finally put the refcount */
224 instance_put(inst);
225
226 module_put(THIS_MODULE);
227}
228
229static inline void
230__instance_destroy(struct nfulnl_instance *inst)
231{
232 _instance_destroy2(inst, 0);
233}
234
235static inline void
236instance_destroy(struct nfulnl_instance *inst)
237{
238 _instance_destroy2(inst, 1);
239}
240
241static int
242nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
243 unsigned int range)
244{
245 int status = 0;
246
247 spin_lock_bh(&inst->lock);
248
249 switch (mode) {
250 case NFULNL_COPY_NONE:
251 case NFULNL_COPY_META:
252 inst->copy_mode = mode;
253 inst->copy_range = 0;
254 break;
255
256 case NFULNL_COPY_PACKET:
257 inst->copy_mode = mode;
258 /* we're using struct nfattr which has 16bit nfa_len */
259 if (range > 0xffff)
260 inst->copy_range = 0xffff;
261 else
262 inst->copy_range = range;
263 break;
264
265 default:
266 status = -EINVAL;
267 break;
268 }
269
270 spin_unlock_bh(&inst->lock);
271
272 return status;
273}
274
275static int
276nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
277{
278 int status;
279
280 spin_lock_bh(&inst->lock);
281 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
282 status = -ERANGE;
283 else if (nlbufsiz > 131072)
284 status = -ERANGE;
285 else {
286 inst->nlbufsiz = nlbufsiz;
287 status = 0;
288 }
289 spin_unlock_bh(&inst->lock);
290
291 return status;
292}
293
294static int
295nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
296{
297 spin_lock_bh(&inst->lock);
298 inst->flushtimeout = timeout;
299 spin_unlock_bh(&inst->lock);
300
301 return 0;
302}
303
304static int
305nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
306{
307 spin_lock_bh(&inst->lock);
308 inst->qthreshold = qthresh;
309 spin_unlock_bh(&inst->lock);
310
311 return 0;
312}
313
314static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
315 unsigned int pkt_size)
316{
317 struct sk_buff *skb;
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 skb = alloc_skb(inst_size, GFP_ATOMIC);
325 if (!skb) {
326 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
327 inst_size);
328
329 /* try to allocate only as much as we need for current
330 * packet */
331
332 skb = alloc_skb(pkt_size, GFP_ATOMIC);
333 if (!skb)
334 PRINTR("nfnetlink_log: can't even alloc %u bytes\n",
335 pkt_size);
336 }
337
338 return skb;
339}
340
341static int
342__nfulnl_send(struct nfulnl_instance *inst)
343{
344 int status;
345
346 if (timer_pending(&inst->timer))
347 del_timer(&inst->timer);
348
349 if (inst->qlen > 1)
350 inst->lastnlh->nlmsg_type = NLMSG_DONE;
351
352 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
353 if (status < 0) {
354 UDEBUG("netlink_unicast() failed\n");
355 /* FIXME: statistics */
356 }
357
358 inst->qlen = 0;
359 inst->skb = NULL;
360 inst->lastnlh = NULL;
361
362 return status;
363}
364
365static void nfulnl_timer(unsigned long data)
366{
367 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
368
369 UDEBUG("timer function called, flushing buffer\n");
370
371 spin_lock_bh(&inst->lock);
372 __nfulnl_send(inst);
373 instance_put(inst);
374 spin_unlock_bh(&inst->lock);
375}
376
377static inline int
378__build_packet_message(struct nfulnl_instance *inst,
379 const struct sk_buff *skb,
380 unsigned int data_len,
381 unsigned int pf,
382 unsigned int hooknum,
383 const struct net_device *indev,
384 const struct net_device *outdev,
385 const struct nf_loginfo *li,
386 const char *prefix)
387{
388 unsigned char *old_tail;
389 struct nfulnl_msg_packet_hdr pmsg;
390 struct nlmsghdr *nlh;
391 struct nfgenmsg *nfmsg;
392 u_int32_t tmp_uint;
393
394 UDEBUG("entered\n");
395
396 old_tail = inst->skb->tail;
397 nlh = NLMSG_PUT(inst->skb, 0, 0,
398 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
399 sizeof(struct nfgenmsg));
400 nfmsg = NLMSG_DATA(nlh);
401 nfmsg->nfgen_family = pf;
402 nfmsg->version = NFNETLINK_V0;
403 nfmsg->res_id = htons(inst->group_num);
404
405 pmsg.hw_protocol = htons(skb->protocol);
406 pmsg.hook = hooknum;
407
408 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
409
410 if (prefix) {
411 int slen = strlen(prefix);
412 if (slen > NFULNL_PREFIXLEN)
413 slen = NFULNL_PREFIXLEN;
414 NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
415 }
416
417 if (indev) {
418 tmp_uint = htonl(indev->ifindex);
fbcd923c 419#ifndef CONFIG_BRIDGE_NETFILTER
0597f268
HW		 420 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
421 &tmp_uint);
fbcd923c
HW		 422#else
423 if (pf == PF_BRIDGE) {
424 /* Case 1: outdev is physical input device, we need to
425 * look for bridge group (when called from
426 * netfilter_bridge) */
427 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
428 sizeof(tmp_uint), &tmp_uint);
429 /* this is the bridge group "brX" */
430 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
431 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
432 sizeof(tmp_uint), &tmp_uint);
433 } else {
434 /* Case 2: indev is bridge group, we need to look for
435 * physical device (when called from ipv4) */
436 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
437 sizeof(tmp_uint), &tmp_uint);
438 if (skb->nf_bridge && skb->nf_bridge->physindev) {
439 tmp_uint =
440 htonl(skb->nf_bridge->physindev->ifindex);
441 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
442 sizeof(tmp_uint), &tmp_uint);
443 }
444 }
445#endif
0597f268
HW		 446 }
447
448 if (outdev) {
449 tmp_uint = htonl(outdev->ifindex);
fbcd923c 450#ifndef CONFIG_BRIDGE_NETFILTER
0597f268
HW		 451 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
452 &tmp_uint);
fbcd923c
HW		 453#else
454 if (pf == PF_BRIDGE) {
455 /* Case 1: outdev is physical output device, we need to
456 * look for bridge group (when called from
457 * netfilter_bridge) */
458 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
459 sizeof(tmp_uint), &tmp_uint);
460 /* this is the bridge group "brX" */
461 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
462 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
463 sizeof(tmp_uint), &tmp_uint);
464 } else {
465 /* Case 2: indev is a bridge group, we need to look
466 * for physical device (when called from ipv4) */
467 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
468 sizeof(tmp_uint), &tmp_uint);
469 if (skb->nf_bridge) {
470 tmp_uint =
471 htonl(skb->nf_bridge->physoutdev->ifindex);
472 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
473 sizeof(tmp_uint), &tmp_uint);
474 }
475 }
476#endif
0597f268
HW		 477 }
478
479 if (skb->nfmark) {
480 tmp_uint = htonl(skb->nfmark);
481 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
482 }
483
484 if (indev && skb->dev && skb->dev->hard_header_parse) {
485 struct nfulnl_msg_packet_hw phw;
486
487 phw.hw_addrlen =
488 skb->dev->hard_header_parse((struct sk_buff *)skb,
489 phw.hw_addr);
490 phw.hw_addrlen = htons(phw.hw_addrlen);
491 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
492 }
493
a61bbcf2 494 if (skb->tstamp.off_sec) {
0597f268
HW		 495 struct nfulnl_msg_packet_timestamp ts;
496
325ed823
HX		 497 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
498 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
0597f268
HW		 499
500 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
501 }
502
503 /* UID */
504 if (skb->sk) {
505 read_lock_bh(&skb->sk->sk_callback_lock);
506 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
507 u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
508 /* need to unlock here since NFA_PUT may goto */
509 read_unlock_bh(&skb->sk->sk_callback_lock);
510 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
511 } else
512 read_unlock_bh(&skb->sk->sk_callback_lock);
513 }
514
515 if (data_len) {
516 struct nfattr *nfa;
517 int size = NFA_LENGTH(data_len);
518
519 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
520 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
521 goto nlmsg_failure;
522 }
523
524 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
525 nfa->nfa_type = NFULA_PAYLOAD;
526 nfa->nfa_len = size;
527
528 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
529 BUG();
530 }
531
532 nlh->nlmsg_len = inst->skb->tail - old_tail;
533 return 0;
534
535nlmsg_failure:
536 UDEBUG("nlmsg_failure\n");
537nfattr_failure:
538 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
539 return -1;
540}
541
542#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
543
544static struct nf_loginfo default_loginfo = {
545 .type = NF_LOG_TYPE_ULOG,
546 .u = {
547 .ulog = {
548 .copy_len = 0xffff,
549 .group = 0,
550 .qthreshold = 1,
551 },
552 },
553};
554
555/* log handler for internal netfilter logging api */
556static void
557nfulnl_log_packet(unsigned int pf,
558 unsigned int hooknum,
559 const struct sk_buff *skb,
560 const struct net_device *in,
561 const struct net_device *out,
562 const struct nf_loginfo *li_user,
563 const char *prefix)
564{
565 unsigned int size, data_len;
566 struct nfulnl_instance *inst;
567 const struct nf_loginfo *li;
568 unsigned int qthreshold;
569 unsigned int nlbufsiz;
570
571 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
572 li = li_user;
573 else
574 li = &default_loginfo;
575
576 inst = instance_lookup_get(li->u.ulog.group);
577 if (!inst)
578 inst = instance_lookup_get(0);
579 if (!inst) {
580 PRINTR("nfnetlink_log: trying to log packet, "
581 "but no instance for group %u\n", li->u.ulog.group);
582 return;
583 }
584
585 /* all macros expand to constant values at compile time */
586 /* FIXME: do we want to make the size calculation conditional based on
587 * what is actually present? way more branches and checks, but more
588 * memory efficient... */
589 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
590 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
591 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
592 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
fbcd923c
HW		 593#ifdef CONFIG_BRIDGE_NETFILTER
594 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
595 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
596#endif
0597f268
HW		 597 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
598 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
599 + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */
600 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
601 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
602
603 UDEBUG("initial size=%u\n", size);
604
605 spin_lock_bh(&inst->lock);
606
607 qthreshold = inst->qthreshold;
608 /* per-rule qthreshold overrides per-instance */
609 if (qthreshold > li->u.ulog.qthreshold)
610 qthreshold = li->u.ulog.qthreshold;
611
612 switch (inst->copy_mode) {
613 case NFULNL_COPY_META:
614 case NFULNL_COPY_NONE:
615 data_len = 0;
616 break;
617
618 case NFULNL_COPY_PACKET:
619 if (inst->copy_range == 0
620 || inst->copy_range > skb->len)
621 data_len = skb->len;
622 else
623 data_len = inst->copy_range;
624
625 size += NFA_SPACE(data_len);
626 UDEBUG("copy_packet, therefore size now %u\n", size);
627 break;
628
629 default:
630 spin_unlock_bh(&inst->lock);
631 instance_put(inst);
632 return;
633 }
634
635 if (size > inst->nlbufsiz)
636 nlbufsiz = size;
637 else
638 nlbufsiz = inst->nlbufsiz;
639
640 if (!inst->skb) {
641 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
642 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
643 inst->nlbufsiz, size);
644 goto alloc_failure;
645 }
646 } else if (inst->qlen >= qthreshold ||
647 size > skb_tailroom(inst->skb)) {
648 /* either the queue len is too high or we don't have
649 * enough room in the skb left. flush to userspace. */
650 UDEBUG("flushing old skb\n");
651
652 __nfulnl_send(inst);
653
654 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
655 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
656 inst->nlbufsiz, size);
657 goto alloc_failure;
658 }
659 }
660
661 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
662 inst->qlen++;
663
664 __build_packet_message(inst, skb, data_len, pf,
665 hooknum, in, out, li, prefix);
666
667 /* timer_pending always called within inst->lock, so there
668 * is no chance of a race here */
669 if (!timer_pending(&inst->timer)) {
670 instance_get(inst);
671 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
672 add_timer(&inst->timer);
673 }
674 spin_unlock_bh(&inst->lock);
675
676 return;
677
678alloc_failure:
679 spin_unlock_bh(&inst->lock);
680 instance_put(inst);
681 UDEBUG("error allocating skb\n");
682 /* FIXME: statistics */
683}
684
685static int
686nfulnl_rcv_nl_event(struct notifier_block *this,
687 unsigned long event, void *ptr)
688{
689 struct netlink_notify *n = ptr;
690
691 if (event == NETLINK_URELEASE &&
692 n->protocol == NETLINK_NETFILTER && n->pid) {
693 int i;
694
695 /* destroy all instances for this pid */
696 write_lock_bh(&instances_lock);
697 for (i = 0; i < INSTANCE_BUCKETS; i++) {
698 struct hlist_node *tmp, *t2;
699 struct nfulnl_instance *inst;
700 struct hlist_head *head = &instance_table[i];
701
702 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
703 UDEBUG("node = %p\n", inst);
704 if (n->pid == inst->peer_pid)
705 __instance_destroy(inst);
706 }
707 }
708 write_unlock_bh(&instances_lock);
709 }
710 return NOTIFY_DONE;
711}
712
713static struct notifier_block nfulnl_rtnl_notifier = {
714 .notifier_call = nfulnl_rcv_nl_event,
715};
716
717static int
718nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
719 struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
720{
721 return -ENOTSUPP;
722}
723
724static struct nf_logger nfulnl_logger = {
725 .name = "nfnetlink_log",
726 .logfn = &nfulnl_log_packet,
727 .me = THIS_MODULE,
728};
729
730static const int nfula_min[NFULA_MAX] = {
731 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
732 [NFULA_MARK-1] = sizeof(u_int32_t),
733 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
734 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
735 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
736 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
737 [NFULA_PAYLOAD-1] = 0,
738 [NFULA_PREFIX-1] = 0,
739 [NFULA_UID-1] = sizeof(u_int32_t),
740};
741
742static const int nfula_cfg_min[NFULA_CFG_MAX] = {
743 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
744 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
745 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
746 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
747 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
748};
749
750static int
751nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
752 struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
753{
754 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
755 u_int16_t group_num = ntohs(nfmsg->res_id);
756 struct nfulnl_instance *inst;
757 int ret = 0;
758
759 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
760
761 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
762 UDEBUG("bad attribute size\n");
763 return -EINVAL;
764 }
765
766 inst = instance_lookup_get(group_num);
767 if (nfula[NFULA_CFG_CMD-1]) {
768 u_int8_t pf = nfmsg->nfgen_family;
769 struct nfulnl_msg_config_cmd *cmd;
770 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
771 UDEBUG("found CFG_CMD for\n");
772
773 switch (cmd->command) {
774 case NFULNL_CFG_CMD_BIND:
775 if (inst) {
776 ret = -EBUSY;
777 goto out_put;
778 }
779
780 inst = instance_create(group_num,
781 NETLINK_CB(skb).pid);
782 if (!inst) {
783 ret = -EINVAL;
784 goto out_put;
785 }
786 break;
787 case NFULNL_CFG_CMD_UNBIND:
788 if (!inst) {
789 ret = -ENODEV;
790 goto out_put;
791 }
792
793 if (inst->peer_pid != NETLINK_CB(skb).pid) {
794 ret = -EPERM;
795 goto out_put;
796 }
797
798 instance_destroy(inst);
799 break;
800 case NFULNL_CFG_CMD_PF_BIND:
801 UDEBUG("registering log handler for pf=%u\n", pf);
802 ret = nf_log_register(pf, &nfulnl_logger);
803 break;
804 case NFULNL_CFG_CMD_PF_UNBIND:
805 UDEBUG("unregistering log handler for pf=%u\n", pf);
806 /* This is a bug and a feature. We cannot unregister
807 * other handlers, like nfnetlink_inst can */
808 nf_log_unregister_pf(pf);
809 break;
810 default:
811 ret = -EINVAL;
812 break;
813 }
814 } else {
815 if (!inst) {
816 UDEBUG("no config command, and no instance for "
817 "group=%u pid=%u =>ENOENT\n",
818 group_num, NETLINK_CB(skb).pid);
819 ret = -ENOENT;
820 goto out_put;
821 }
822
823 if (inst->peer_pid != NETLINK_CB(skb).pid) {
824 UDEBUG("no config command, and wrong pid\n");
825 ret = -EPERM;
826 goto out_put;
827 }
828 }
829
830 if (nfula[NFULA_CFG_MODE-1]) {
831 struct nfulnl_msg_config_mode *params;
832 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
833
834 nfulnl_set_mode(inst, params->copy_mode,
835 ntohs(params->copy_range));
836 }
837
838 if (nfula[NFULA_CFG_TIMEOUT-1]) {
839 u_int32_t timeout =
840 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
841
842 nfulnl_set_timeout(inst, ntohl(timeout));
843 }
844
845 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
846 u_int32_t nlbufsiz =
847 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
848
849 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
850 }
851
852 if (nfula[NFULA_CFG_QTHRESH-1]) {
853 u_int32_t qthresh =
854 *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
855
856 nfulnl_set_qthresh(inst, ntohl(qthresh));
857 }
858
859out_put:
860 instance_put(inst);
861 return ret;
862}
863
864static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
865 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
927ccbcc
HW		 866 .attr_count = NFULA_MAX,
867 .cap_required = CAP_NET_ADMIN, },
0597f268 868 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
927ccbcc 869 .attr_count = NFULA_CFG_MAX,
0597f268
HW		 870 .cap_required = CAP_NET_ADMIN },
871};
872
873static struct nfnetlink_subsystem nfulnl_subsys = {
874 .name = "log",
875 .subsys_id = NFNL_SUBSYS_ULOG,
876 .cb_count = NFULNL_MSG_MAX,
0597f268
HW		 877 .cb = nfulnl_cb,
878};
879
880#ifdef CONFIG_PROC_FS
881struct iter_state {
882 unsigned int bucket;
883};
884
885static struct hlist_node *get_first(struct seq_file *seq)
886{
887 struct iter_state *st = seq->private;
888
889 if (!st)
890 return NULL;
891
892 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
893 if (!hlist_empty(&instance_table[st->bucket]))
894 return instance_table[st->bucket].first;
895 }
896 return NULL;
897}
898
899static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
900{
901 struct iter_state *st = seq->private;
902
903 h = h->next;
904 while (!h) {
905 if (++st->bucket >= INSTANCE_BUCKETS)
906 return NULL;
907
908 h = instance_table[st->bucket].first;
909 }
910 return h;
911}
912
913static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
914{
915 struct hlist_node *head;
916 head = get_first(seq);
917
918 if (head)
919 while (pos && (head = get_next(seq, head)))
920 pos--;
921 return pos ? NULL : head;
922}
923
924static void *seq_start(struct seq_file *seq, loff_t *pos)
925{
926 read_lock_bh(&instances_lock);
927 return get_idx(seq, *pos);
928}
929
930static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
931{
932 (*pos)++;
933 return get_next(s, v);
934}
935
936static void seq_stop(struct seq_file *s, void *v)
937{
938 read_unlock_bh(&instances_lock);
939}
940
941static int seq_show(struct seq_file *s, void *v)
942{
943 const struct nfulnl_instance *inst = v;
944
945 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
946 inst->group_num,
947 inst->peer_pid, inst->qlen,
948 inst->copy_mode, inst->copy_range,
949 inst->flushtimeout, atomic_read(&inst->use));
950}
951
952static struct seq_operations nful_seq_ops = {
953 .start = seq_start,
954 .next = seq_next,
955 .stop = seq_stop,
956 .show = seq_show,
957};
958
959static int nful_open(struct inode *inode, struct file *file)
960{
961 struct seq_file *seq;
962 struct iter_state *is;
963 int ret;
964
965 is = kmalloc(sizeof(*is), GFP_KERNEL);
966 if (!is)
967 return -ENOMEM;
968 memset(is, 0, sizeof(*is));
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;
975out_free:
976 kfree(is);
977 return ret;
978}
979
980static 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
990static int
991init_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
1026cleanup:
1027 nf_log_unregister_logger(&nfulnl_logger);
1028#ifdef CONFIG_PROC_FS
1029 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1030cleanup_subsys:
1031#endif
1032 nfnetlink_subsys_unregister(&nfulnl_subsys);
1033cleanup_netlink_notifier:
1034 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1035 return status;
1036}
1037
1038static int __init init(void)
1039{
1040
1041 return init_or_cleanup(1);
1042}
1043
1044static void __exit fini(void)
1045{
1046 init_or_cleanup(0);
1047}
1048
1049MODULE_DESCRIPTION("netfilter userspace logging");
1050MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1051MODULE_LICENSE("GPL");
f682faef 1052MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
0597f268
HW		 1053
1054module_init(init);
1055module_exit(fini);
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