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Fix reference counting (memory leak) problem in __nfulnl_send() and callers related...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / netfilter / nfnetlink_log.c
blobc35be233eaa21d419cf7a4ed6e0cb1aa985976c7
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 /* timer "holds" one reference (we have one more) */
214 if (timer_pending(&inst->timer)) {
215 del_timer(&inst->timer);
216 instance_put(inst);
217 }
218 if (inst->qlen)
219 __nfulnl_send(inst);
220 if (inst->skb) {
221 kfree_skb(inst->skb);
222 inst->skb = NULL;
223 }
224 }
225 spin_unlock_bh(&inst->lock);
226
227 /* and finally put the refcount */
228 instance_put(inst);
229
230 module_put(THIS_MODULE);
231 }
232
233 static inline void
234 __instance_destroy(struct nfulnl_instance *inst)
235 {
236 _instance_destroy2(inst, 0);
237 }
238
239 static inline void
240 instance_destroy(struct nfulnl_instance *inst)
241 {
242 _instance_destroy2(inst, 1);
243 }
244
245 static int
246 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
247 unsigned int range)
248 {
249 int status = 0;
250
251 spin_lock_bh(&inst->lock);
252
253 switch (mode) {
254 case NFULNL_COPY_NONE:
255 case NFULNL_COPY_META:
256 inst->copy_mode = mode;
257 inst->copy_range = 0;
258 break;
259
260 case NFULNL_COPY_PACKET:
261 inst->copy_mode = mode;
262 /* we're using struct nfattr which has 16bit nfa_len */
263 if (range > 0xffff)
264 inst->copy_range = 0xffff;
265 else
266 inst->copy_range = range;
267 break;
268
269 default:
270 status = -EINVAL;
271 break;
272 }
273
274 spin_unlock_bh(&inst->lock);
275
276 return status;
277 }
278
279 static int
280 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
281 {
282 int status;
283
284 spin_lock_bh(&inst->lock);
285 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
286 status = -ERANGE;
287 else if (nlbufsiz > 131072)
288 status = -ERANGE;
289 else {
290 inst->nlbufsiz = nlbufsiz;
291 status = 0;
292 }
293 spin_unlock_bh(&inst->lock);
294
295 return status;
296 }
297
298 static int
299 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
300 {
301 spin_lock_bh(&inst->lock);
302 inst->flushtimeout = timeout;
303 spin_unlock_bh(&inst->lock);
304
305 return 0;
306 }
307
308 static int
309 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
310 {
311 spin_lock_bh(&inst->lock);
312 inst->qthreshold = qthresh;
313 spin_unlock_bh(&inst->lock);
314
315 return 0;
316 }
317
318 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
319 unsigned int pkt_size)
320 {
321 struct sk_buff *skb;
322 unsigned int n;
323
324 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
325
326 /* alloc skb which should be big enough for a whole multipart
327 * message. WARNING: has to be <= 128k due to slab restrictions */
328
329 n = max(inst_size, pkt_size);
330 skb = alloc_skb(n, GFP_ATOMIC);
331 if (!skb) {
332 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
333 inst_size);
334
335 if (n > pkt_size) {
336 /* try to allocate only as much as we need for current
337 * packet */
338
339 skb = alloc_skb(pkt_size, GFP_ATOMIC);
340 if (!skb)
341 PRINTR("nfnetlink_log: can't even alloc %u "
342 "bytes\n", pkt_size);
343 }
344 }
345
346 return skb;
347 }
348
349 static int
350 __nfulnl_send(struct nfulnl_instance *inst)
351 {
352 int status;
353
354 if (!inst->skb)
355 return 0;
356
357 if (inst->qlen > 1)
358 inst->lastnlh->nlmsg_type = NLMSG_DONE;
359
360 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
361 if (status < 0) {
362 UDEBUG("netlink_unicast() failed\n");
363 /* FIXME: statistics */
364 }
365
366 inst->qlen = 0;
367 inst->skb = NULL;
368 inst->lastnlh = NULL;
369
370 return status;
371 }
372
373 static void nfulnl_timer(unsigned long data)
374 {
375 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
376
377 UDEBUG("timer function called, flushing buffer\n");
378
379 spin_lock_bh(&inst->lock);
380 if (timer_pending(&inst->timer)) /* is it always true or false here? */
381 del_timer(&inst->timer);
382 __nfulnl_send(inst);
383 instance_put(inst);
384 spin_unlock_bh(&inst->lock);
385 }
386
387 static inline int
388 __build_packet_message(struct nfulnl_instance *inst,
389 const struct sk_buff *skb,
390 unsigned int data_len,
391 unsigned int pf,
392 unsigned int hooknum,
393 const struct net_device *indev,
394 const struct net_device *outdev,
395 const struct nf_loginfo *li,
396 const char *prefix)
397 {
398 unsigned char *old_tail;
399 struct nfulnl_msg_packet_hdr pmsg;
400 struct nlmsghdr *nlh;
401 struct nfgenmsg *nfmsg;
402 u_int32_t tmp_uint;
403
404 UDEBUG("entered\n");
405
406 old_tail = inst->skb->tail;
407 nlh = NLMSG_PUT(inst->skb, 0, 0,
408 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
409 sizeof(struct nfgenmsg));
410 nfmsg = NLMSG_DATA(nlh);
411 nfmsg->nfgen_family = pf;
412 nfmsg->version = NFNETLINK_V0;
413 nfmsg->res_id = htons(inst->group_num);
414
415 pmsg.hw_protocol = htons(skb->protocol);
416 pmsg.hook = hooknum;
417
418 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
419
420 if (prefix) {
421 int slen = strlen(prefix);
422 if (slen > NFULNL_PREFIXLEN)
423 slen = NFULNL_PREFIXLEN;
424 NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
425 }
426
427 if (indev) {
428 tmp_uint = htonl(indev->ifindex);
429 #ifndef CONFIG_BRIDGE_NETFILTER
430 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
431 &tmp_uint);
432 #else
433 if (pf == PF_BRIDGE) {
434 /* Case 1: outdev is physical input device, we need to
435 * look for bridge group (when called from
436 * netfilter_bridge) */
437 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
438 sizeof(tmp_uint), &tmp_uint);
439 /* this is the bridge group "brX" */
440 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
441 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
442 sizeof(tmp_uint), &tmp_uint);
443 } else {
444 /* Case 2: indev is bridge group, we need to look for
445 * physical device (when called from ipv4) */
446 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
447 sizeof(tmp_uint), &tmp_uint);
448 if (skb->nf_bridge && skb->nf_bridge->physindev) {
449 tmp_uint =
450 htonl(skb->nf_bridge->physindev->ifindex);
451 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
452 sizeof(tmp_uint), &tmp_uint);
453 }
454 }
455 #endif
456 }
457
458 if (outdev) {
459 tmp_uint = htonl(outdev->ifindex);
460 #ifndef CONFIG_BRIDGE_NETFILTER
461 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
462 &tmp_uint);
463 #else
464 if (pf == PF_BRIDGE) {
465 /* Case 1: outdev is physical output device, we need to
466 * look for bridge group (when called from
467 * netfilter_bridge) */
468 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
469 sizeof(tmp_uint), &tmp_uint);
470 /* this is the bridge group "brX" */
471 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
472 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
473 sizeof(tmp_uint), &tmp_uint);
474 } else {
475 /* Case 2: indev is a bridge group, we need to look
476 * for physical device (when called from ipv4) */
477 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
478 sizeof(tmp_uint), &tmp_uint);
479 if (skb->nf_bridge) {
480 tmp_uint =
481 htonl(skb->nf_bridge->physoutdev->ifindex);
482 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
483 sizeof(tmp_uint), &tmp_uint);
484 }
485 }
486 #endif
487 }
488
489 if (skb->nfmark) {
490 tmp_uint = htonl(skb->nfmark);
491 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
492 }
493
494 if (indev && skb->dev && skb->dev->hard_header_parse) {
495 struct nfulnl_msg_packet_hw phw;
496
497 phw.hw_addrlen =
498 skb->dev->hard_header_parse((struct sk_buff *)skb,
499 phw.hw_addr);
500 phw.hw_addrlen = htons(phw.hw_addrlen);
501 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
502 }
503
504 if (skb->tstamp.off_sec) {
505 struct nfulnl_msg_packet_timestamp ts;
506
507 ts.sec = cpu_to_be64(skb->tstamp.off_sec);
508 ts.usec = cpu_to_be64(skb->tstamp.off_usec);
509
510 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
511 }
512
513 /* UID */
514 if (skb->sk) {
515 read_lock_bh(&skb->sk->sk_callback_lock);
516 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
517 u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
518 /* need to unlock here since NFA_PUT may goto */
519 read_unlock_bh(&skb->sk->sk_callback_lock);
520 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
521 } else
522 read_unlock_bh(&skb->sk->sk_callback_lock);
523 }
524
525 if (data_len) {
526 struct nfattr *nfa;
527 int size = NFA_LENGTH(data_len);
528
529 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
530 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
531 goto nlmsg_failure;
532 }
533
534 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
535 nfa->nfa_type = NFULA_PAYLOAD;
536 nfa->nfa_len = size;
537
538 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
539 BUG();
540 }
541
542 nlh->nlmsg_len = inst->skb->tail - old_tail;
543 return 0;
544
545 nlmsg_failure:
546 UDEBUG("nlmsg_failure\n");
547 nfattr_failure:
548 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
549 return -1;
550 }
551
552 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
553
554 static struct nf_loginfo default_loginfo = {
555 .type = NF_LOG_TYPE_ULOG,
556 .u = {
557 .ulog = {
558 .copy_len = 0xffff,
559 .group = 0,
560 .qthreshold = 1,
561 },
562 },
563 };
564
565 /* log handler for internal netfilter logging api */
566 static void
567 nfulnl_log_packet(unsigned int pf,
568 unsigned int hooknum,
569 const struct sk_buff *skb,
570 const struct net_device *in,
571 const struct net_device *out,
572 const struct nf_loginfo *li_user,
573 const char *prefix)
574 {
575 unsigned int size, data_len;
576 struct nfulnl_instance *inst;
577 const struct nf_loginfo *li;
578 unsigned int qthreshold;
579 unsigned int nlbufsiz;
580
581 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
582 li = li_user;
583 else
584 li = &default_loginfo;
585
586 inst = instance_lookup_get(li->u.ulog.group);
587 if (!inst)
588 inst = instance_lookup_get(0);
589 if (!inst) {
590 PRINTR("nfnetlink_log: trying to log packet, "
591 "but no instance for group %u\n", li->u.ulog.group);
592 return;
593 }
594
595 /* all macros expand to constant values at compile time */
596 /* FIXME: do we want to make the size calculation conditional based on
597 * what is actually present? way more branches and checks, but more
598 * memory efficient... */
599 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
600 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
601 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
602 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
603 #ifdef CONFIG_BRIDGE_NETFILTER
604 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
605 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
606 #endif
607 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
608 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
609 + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */
610 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
611 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
612
613 UDEBUG("initial size=%u\n", size);
614
615 spin_lock_bh(&inst->lock);
616
617 qthreshold = inst->qthreshold;
618 /* per-rule qthreshold overrides per-instance */
619 if (qthreshold > li->u.ulog.qthreshold)
620 qthreshold = li->u.ulog.qthreshold;
621
622 switch (inst->copy_mode) {
623 case NFULNL_COPY_META:
624 case NFULNL_COPY_NONE:
625 data_len = 0;
626 break;
627
628 case NFULNL_COPY_PACKET:
629 if (inst->copy_range == 0
630 || inst->copy_range > skb->len)
631 data_len = skb->len;
632 else
633 data_len = inst->copy_range;
634
635 size += NFA_SPACE(data_len);
636 UDEBUG("copy_packet, therefore size now %u\n", size);
637 break;
638
639 default:
640 spin_unlock_bh(&inst->lock);
641 instance_put(inst);
642 return;
643 }
644
645 if (size > inst->nlbufsiz)
646 nlbufsiz = size;
647 else
648 nlbufsiz = inst->nlbufsiz;
649
650 if (!inst->skb) {
651 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
652 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
653 inst->nlbufsiz, size);
654 goto alloc_failure;
655 }
656 } else if (inst->qlen >= qthreshold ||
657 size > skb_tailroom(inst->skb)) {
658 /* either the queue len is too high or we don't have
659 * enough room in the skb left. flush to userspace. */
660 UDEBUG("flushing old skb\n");
661
662 /* timer "holds" one reference (we have another one) */
663 if (timer_pending(&inst->timer)) {
664 del_timer(&inst->timer);
665 instance_put(inst);
666 }
667 __nfulnl_send(inst);
668
669 if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
670 UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
671 inst->nlbufsiz, size);
672 goto alloc_failure;
673 }
674 }
675
676 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
677 inst->qlen++;
678
679 __build_packet_message(inst, skb, data_len, pf,
680 hooknum, in, out, li, prefix);
681
682 /* timer_pending always called within inst->lock, so there
683 * is no chance of a race here */
684 if (!timer_pending(&inst->timer)) {
685 instance_get(inst);
686 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
687 add_timer(&inst->timer);
688 }
689 spin_unlock_bh(&inst->lock);
690
691 return;
692
693 alloc_failure:
694 spin_unlock_bh(&inst->lock);
695 instance_put(inst);
696 UDEBUG("error allocating skb\n");
697 /* FIXME: statistics */
698 }
699
700 static int
701 nfulnl_rcv_nl_event(struct notifier_block *this,
702 unsigned long event, void *ptr)
703 {
704 struct netlink_notify *n = ptr;
705
706 if (event == NETLINK_URELEASE &&
707 n->protocol == NETLINK_NETFILTER && n->pid) {
708 int i;
709
710 /* destroy all instances for this pid */
711 write_lock_bh(&instances_lock);
712 for (i = 0; i < INSTANCE_BUCKETS; i++) {
713 struct hlist_node *tmp, *t2;
714 struct nfulnl_instance *inst;
715 struct hlist_head *head = &instance_table[i];
716
717 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
718 UDEBUG("node = %p\n", inst);
719 if (n->pid == inst->peer_pid)
720 __instance_destroy(inst);
721 }
722 }
723 write_unlock_bh(&instances_lock);
724 }
725 return NOTIFY_DONE;
726 }
727
728 static struct notifier_block nfulnl_rtnl_notifier = {
729 .notifier_call = nfulnl_rcv_nl_event,
730 };
731
732 static int
733 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
734 struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
735 {
736 return -ENOTSUPP;
737 }
738
739 static struct nf_logger nfulnl_logger = {
740 .name = "nfnetlink_log",
741 .logfn = &nfulnl_log_packet,
742 .me = THIS_MODULE,
743 };
744
745 static const int nfula_min[NFULA_MAX] = {
746 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
747 [NFULA_MARK-1] = sizeof(u_int32_t),
748 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
749 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
750 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
751 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
752 [NFULA_PAYLOAD-1] = 0,
753 [NFULA_PREFIX-1] = 0,
754 [NFULA_UID-1] = sizeof(u_int32_t),
755 };
756
757 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
758 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
759 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
760 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
761 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
762 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
763 };
764
765 static int
766 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
767 struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
768 {
769 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
770 u_int16_t group_num = ntohs(nfmsg->res_id);
771 struct nfulnl_instance *inst;
772 int ret = 0;
773
774 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
775
776 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
777 UDEBUG("bad attribute size\n");
778 return -EINVAL;
779 }
780
781 inst = instance_lookup_get(group_num);
782 if (nfula[NFULA_CFG_CMD-1]) {
783 u_int8_t pf = nfmsg->nfgen_family;
784 struct nfulnl_msg_config_cmd *cmd;
785 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
786 UDEBUG("found CFG_CMD for\n");
787
788 switch (cmd->command) {
789 case NFULNL_CFG_CMD_BIND:
790 if (inst) {
791 ret = -EBUSY;
792 goto out_put;
793 }
794
795 inst = instance_create(group_num,
796 NETLINK_CB(skb).pid);
797 if (!inst) {
798 ret = -EINVAL;
799 goto out_put;
800 }
801 break;
802 case NFULNL_CFG_CMD_UNBIND:
803 if (!inst) {
804 ret = -ENODEV;
805 goto out_put;
806 }
807
808 if (inst->peer_pid != NETLINK_CB(skb).pid) {
809 ret = -EPERM;
810 goto out_put;
811 }
812
813 instance_destroy(inst);
814 break;
815 case NFULNL_CFG_CMD_PF_BIND:
816 UDEBUG("registering log handler for pf=%u\n", pf);
817 ret = nf_log_register(pf, &nfulnl_logger);
818 break;
819 case NFULNL_CFG_CMD_PF_UNBIND:
820 UDEBUG("unregistering log handler for pf=%u\n", pf);
821 /* This is a bug and a feature. We cannot unregister
822 * other handlers, like nfnetlink_inst can */
823 nf_log_unregister_pf(pf);
824 break;
825 default:
826 ret = -EINVAL;
827 break;
828 }
829 } else {
830 if (!inst) {
831 UDEBUG("no config command, and no instance for "
832 "group=%u pid=%u =>ENOENT\n",
833 group_num, NETLINK_CB(skb).pid);
834 ret = -ENOENT;
835 goto out_put;
836 }
837
838 if (inst->peer_pid != NETLINK_CB(skb).pid) {
839 UDEBUG("no config command, and wrong pid\n");
840 ret = -EPERM;
841 goto out_put;
842 }
843 }
844
845 if (nfula[NFULA_CFG_MODE-1]) {
846 struct nfulnl_msg_config_mode *params;
847 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
848
849 nfulnl_set_mode(inst, params->copy_mode,
850 ntohs(params->copy_range));
851 }
852
853 if (nfula[NFULA_CFG_TIMEOUT-1]) {
854 u_int32_t timeout =
855 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
856
857 nfulnl_set_timeout(inst, ntohl(timeout));
858 }
859
860 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
861 u_int32_t nlbufsiz =
862 *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
863
864 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
865 }
866
867 if (nfula[NFULA_CFG_QTHRESH-1]) {
868 u_int32_t qthresh =
869 *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
870
871 nfulnl_set_qthresh(inst, ntohl(qthresh));
872 }
873
874 out_put:
875 instance_put(inst);
876 return ret;
877 }
878
879 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
880 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
881 .attr_count = NFULA_MAX, },
882 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
883 .attr_count = NFULA_CFG_MAX, },
884 };
885
886 static struct nfnetlink_subsystem nfulnl_subsys = {
887 .name = "log",
888 .subsys_id = NFNL_SUBSYS_ULOG,
889 .cb_count = NFULNL_MSG_MAX,
890 .cb = nfulnl_cb,
891 };
892
893 #ifdef CONFIG_PROC_FS
894 struct iter_state {
895 unsigned int bucket;
896 };
897
898 static struct hlist_node *get_first(struct seq_file *seq)
899 {
900 struct iter_state *st = seq->private;
901
902 if (!st)
903 return NULL;
904
905 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
906 if (!hlist_empty(&instance_table[st->bucket]))
907 return instance_table[st->bucket].first;
908 }
909 return NULL;
910 }
911
912 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
913 {
914 struct iter_state *st = seq->private;
915
916 h = h->next;
917 while (!h) {
918 if (++st->bucket >= INSTANCE_BUCKETS)
919 return NULL;
920
921 h = instance_table[st->bucket].first;
922 }
923 return h;
924 }
925
926 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
927 {
928 struct hlist_node *head;
929 head = get_first(seq);
930
931 if (head)
932 while (pos && (head = get_next(seq, head)))
933 pos--;
934 return pos ? NULL : head;
935 }
936
937 static void *seq_start(struct seq_file *seq, loff_t *pos)
938 {
939 read_lock_bh(&instances_lock);
940 return get_idx(seq, *pos);
941 }
942
943 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
944 {
945 (*pos)++;
946 return get_next(s, v);
947 }
948
949 static void seq_stop(struct seq_file *s, void *v)
950 {
951 read_unlock_bh(&instances_lock);
952 }
953
954 static int seq_show(struct seq_file *s, void *v)
955 {
956 const struct nfulnl_instance *inst = v;
957
958 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
959 inst->group_num,
960 inst->peer_pid, inst->qlen,
961 inst->copy_mode, inst->copy_range,
962 inst->flushtimeout, atomic_read(&inst->use));
963 }
964
965 static struct seq_operations nful_seq_ops = {
966 .start = seq_start,
967 .next = seq_next,
968 .stop = seq_stop,
969 .show = seq_show,
970 };
971
972 static int nful_open(struct inode *inode, struct file *file)
973 {
974 struct seq_file *seq;
975 struct iter_state *is;
976 int ret;
977
978 is = kzalloc(sizeof(*is), GFP_KERNEL);
979 if (!is)
980 return -ENOMEM;
981 ret = seq_open(file, &nful_seq_ops);
982 if (ret < 0)
983 goto out_free;
984 seq = file->private_data;
985 seq->private = is;
986 return ret;
987 out_free:
988 kfree(is);
989 return ret;
990 }
991
992 static struct file_operations nful_file_ops = {
993 .owner = THIS_MODULE,
994 .open = nful_open,
995 .read = seq_read,
996 .llseek = seq_lseek,
997 .release = seq_release_private,
998 };
999
1000 #endif /* PROC_FS */
1001
1002 static int
1003 init_or_cleanup(int init)
1004 {
1005 int i, status = -ENOMEM;
1006 #ifdef CONFIG_PROC_FS
1007 struct proc_dir_entry *proc_nful;
1008 #endif
1009
1010 if (!init)
1011 goto cleanup;
1012
1013 for (i = 0; i < INSTANCE_BUCKETS; i++)
1014 INIT_HLIST_HEAD(&instance_table[i]);
1015
1016 /* it's not really all that important to have a random value, so
1017 * we can do this from the init function, even if there hasn't
1018 * been that much entropy yet */
1019 get_random_bytes(&hash_init, sizeof(hash_init));
1020
1021 netlink_register_notifier(&nfulnl_rtnl_notifier);
1022 status = nfnetlink_subsys_register(&nfulnl_subsys);
1023 if (status < 0) {
1024 printk(KERN_ERR "log: failed to create netlink socket\n");
1025 goto cleanup_netlink_notifier;
1026 }
1027
1028 #ifdef CONFIG_PROC_FS
1029 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1030 proc_net_netfilter);
1031 if (!proc_nful)
1032 goto cleanup_subsys;
1033 proc_nful->proc_fops = &nful_file_ops;
1034 #endif
1035
1036 return status;
1037
1038 cleanup:
1039 nf_log_unregister_logger(&nfulnl_logger);
1040 #ifdef CONFIG_PROC_FS
1041 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1042 cleanup_subsys:
1043 #endif
1044 nfnetlink_subsys_unregister(&nfulnl_subsys);
1045 cleanup_netlink_notifier:
1046 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1047 return status;
1048 }
1049
1050 static int __init init(void)
1051 {
1052
1053 return init_or_cleanup(1);
1054 }
1055
1056 static void __exit fini(void)
1057 {
1058 init_or_cleanup(0);
1059 }
1060
1061 MODULE_DESCRIPTION("netfilter userspace logging");
1062 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1063 MODULE_LICENSE("GPL");
1064 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1065
1066 module_init(init);
1067 module_exit(fini);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree