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[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 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/init.h>
17 #include <linux/ip.h>
18 #include <linux/ipv6.h>
19 #include <linux/netdevice.h>
20 #include <linux/netfilter.h>
21 #include <linux/netlink.h>
22 #include <linux/netfilter/nfnetlink.h>
23 #include <linux/netfilter/nfnetlink_log.h>
24 #include <linux/spinlock.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/list.h>
29 #include <linux/jhash.h>
30 #include <linux/random.h>
31 #include <net/sock.h>
32
33 #include <asm/atomic.h>
34
35 #ifdef CONFIG_BRIDGE_NETFILTER
36 #include "../bridge/br_private.h"
37 #endif
38
39 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
40 #define NFULNL_TIMEOUT_DEFAULT HZ /* every second */
41 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
42 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
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 timer_list timer;
63 int peer_pid; /* PID of the peer process */
64
65 /* configurable parameters */
66 unsigned int flushtimeout; /* timeout until queue flush */
67 unsigned int nlbufsiz; /* netlink buffer allocation size */
68 unsigned int qthreshold; /* threshold of the queue */
69 u_int32_t copy_range;
70 u_int32_t seq; /* instance-local sequential counter */
71 u_int16_t group_num; /* number of this queue */
72 u_int16_t flags;
73 u_int8_t copy_mode;
74 };
75
76 static DEFINE_RWLOCK(instances_lock);
77 static atomic_t global_seq;
78
79 #define INSTANCE_BUCKETS 16
80 static struct hlist_head instance_table[INSTANCE_BUCKETS];
81 static unsigned int hash_init;
82
83 static inline u_int8_t instance_hashfn(u_int16_t group_num)
84 {
85 return ((group_num & 0xff) % INSTANCE_BUCKETS);
86 }
87
88 static struct nfulnl_instance *
89 __instance_lookup(u_int16_t group_num)
90 {
91 struct hlist_head *head;
92 struct hlist_node *pos;
93 struct nfulnl_instance *inst;
94
95 UDEBUG("entering (group_num=%u)\n", group_num);
96
97 head = &instance_table[instance_hashfn(group_num)];
98 hlist_for_each_entry(inst, pos, head, hlist) {
99 if (inst->group_num == group_num)
100 return inst;
101 }
102 return NULL;
103 }
104
105 static inline void
106 instance_get(struct nfulnl_instance *inst)
107 {
108 atomic_inc(&inst->use);
109 }
110
111 static struct nfulnl_instance *
112 instance_lookup_get(u_int16_t group_num)
113 {
114 struct nfulnl_instance *inst;
115
116 read_lock_bh(&instances_lock);
117 inst = __instance_lookup(group_num);
118 if (inst)
119 instance_get(inst);
120 read_unlock_bh(&instances_lock);
121
122 return inst;
123 }
124
125 static void
126 instance_put(struct nfulnl_instance *inst)
127 {
128 if (inst && atomic_dec_and_test(&inst->use)) {
129 UDEBUG("kfree(inst=%p)\n", inst);
130 kfree(inst);
131 module_put(THIS_MODULE);
132 }
133 }
134
135 static void nfulnl_timer(unsigned long data);
136
137 static struct nfulnl_instance *
138 instance_create(u_int16_t group_num, int pid)
139 {
140 struct nfulnl_instance *inst;
141
142 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
143 pid);
144
145 write_lock_bh(&instances_lock);
146 if (__instance_lookup(group_num)) {
147 inst = NULL;
148 UDEBUG("aborting, instance already exists\n");
149 goto out_unlock;
150 }
151
152 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
153 if (!inst)
154 goto out_unlock;
155
156 if (!try_module_get(THIS_MODULE)) {
157 kfree(inst);
158 goto out_unlock;
159 }
160
161 INIT_HLIST_NODE(&inst->hlist);
162 spin_lock_init(&inst->lock);
163 /* needs to be two, since we _put() after creation */
164 atomic_set(&inst->use, 2);
165
166 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
167
168 inst->peer_pid = pid;
169 inst->group_num = group_num;
170
171 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
172 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
173 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
174 inst->copy_mode = NFULNL_COPY_PACKET;
175 inst->copy_range = NFULNL_COPY_RANGE_MAX;
176
177 hlist_add_head(&inst->hlist,
178 &instance_table[instance_hashfn(group_num)]);
179
180 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
181 inst->hlist.next);
182
183 write_unlock_bh(&instances_lock);
184
185 return inst;
186
187 out_unlock:
188 write_unlock_bh(&instances_lock);
189 return NULL;
190 }
191
192 static void __nfulnl_flush(struct nfulnl_instance *inst);
193
194 static void
195 __instance_destroy(struct nfulnl_instance *inst)
196 {
197 /* first pull it out of the global list */
198 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
199 inst, inst->group_num);
200
201 hlist_del(&inst->hlist);
202
203 /* then flush all pending packets from skb */
204
205 spin_lock_bh(&inst->lock);
206 if (inst->skb)
207 __nfulnl_flush(inst);
208 spin_unlock_bh(&inst->lock);
209
210 /* and finally put the refcount */
211 instance_put(inst);
212 }
213
214 static inline void
215 instance_destroy(struct nfulnl_instance *inst)
216 {
217 write_lock_bh(&instances_lock);
218 __instance_destroy(inst);
219 write_unlock_bh(&instances_lock);
220 }
221
222 static int
223 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
224 unsigned int range)
225 {
226 int status = 0;
227
228 spin_lock_bh(&inst->lock);
229
230 switch (mode) {
231 case NFULNL_COPY_NONE:
232 case NFULNL_COPY_META:
233 inst->copy_mode = mode;
234 inst->copy_range = 0;
235 break;
236
237 case NFULNL_COPY_PACKET:
238 inst->copy_mode = mode;
239 inst->copy_range = min_t(unsigned int,
240 range, NFULNL_COPY_RANGE_MAX);
241 break;
242
243 default:
244 status = -EINVAL;
245 break;
246 }
247
248 spin_unlock_bh(&inst->lock);
249
250 return status;
251 }
252
253 static int
254 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
255 {
256 int status;
257
258 spin_lock_bh(&inst->lock);
259 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
260 status = -ERANGE;
261 else if (nlbufsiz > 131072)
262 status = -ERANGE;
263 else {
264 inst->nlbufsiz = nlbufsiz;
265 status = 0;
266 }
267 spin_unlock_bh(&inst->lock);
268
269 return status;
270 }
271
272 static int
273 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
274 {
275 spin_lock_bh(&inst->lock);
276 inst->flushtimeout = timeout;
277 spin_unlock_bh(&inst->lock);
278
279 return 0;
280 }
281
282 static int
283 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
284 {
285 spin_lock_bh(&inst->lock);
286 inst->qthreshold = qthresh;
287 spin_unlock_bh(&inst->lock);
288
289 return 0;
290 }
291
292 static int
293 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
294 {
295 spin_lock_bh(&inst->lock);
296 inst->flags = flags;
297 spin_unlock_bh(&inst->lock);
298
299 return 0;
300 }
301
302 static struct sk_buff *
303 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
304 {
305 struct sk_buff *skb;
306 unsigned int n;
307
308 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
309
310 /* alloc skb which should be big enough for a whole multipart
311 * message. WARNING: has to be <= 128k due to slab restrictions */
312
313 n = max(inst_size, pkt_size);
314 skb = alloc_skb(n, GFP_ATOMIC);
315 if (!skb) {
316 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
317 inst_size);
318
319 if (n > pkt_size) {
320 /* try to allocate only as much as we need for current
321 * packet */
322
323 skb = alloc_skb(pkt_size, GFP_ATOMIC);
324 if (!skb)
325 PRINTR("nfnetlink_log: can't even alloc %u "
326 "bytes\n", pkt_size);
327 }
328 }
329
330 return skb;
331 }
332
333 static int
334 __nfulnl_send(struct nfulnl_instance *inst)
335 {
336 int status = -1;
337
338 if (inst->qlen > 1)
339 NLMSG_PUT(inst->skb, 0, 0,
340 NLMSG_DONE,
341 sizeof(struct nfgenmsg));
342
343 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
344 if (status < 0) {
345 UDEBUG("netlink_unicast() failed\n");
346 /* FIXME: statistics */
347 }
348
349 inst->qlen = 0;
350 inst->skb = NULL;
351
352 nlmsg_failure:
353 return status;
354 }
355
356 static void
357 __nfulnl_flush(struct nfulnl_instance *inst)
358 {
359 /* timer holds a reference */
360 if (del_timer(&inst->timer))
361 instance_put(inst);
362 if (inst->skb)
363 __nfulnl_send(inst);
364 }
365
366 static void
367 nfulnl_timer(unsigned long data)
368 {
369 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
370
371 UDEBUG("timer function called, flushing buffer\n");
372
373 spin_lock_bh(&inst->lock);
374 if (inst->skb)
375 __nfulnl_send(inst);
376 spin_unlock_bh(&inst->lock);
377 instance_put(inst);
378 }
379
380 /* This is an inline function, we don't really care about a long
381 * list of arguments */
382 static inline int
383 __build_packet_message(struct nfulnl_instance *inst,
384 const struct sk_buff *skb,
385 unsigned int data_len,
386 unsigned int pf,
387 unsigned int hooknum,
388 const struct net_device *indev,
389 const struct net_device *outdev,
390 const struct nf_loginfo *li,
391 const char *prefix, unsigned int plen)
392 {
393 struct nfulnl_msg_packet_hdr pmsg;
394 struct nlmsghdr *nlh;
395 struct nfgenmsg *nfmsg;
396 __be32 tmp_uint;
397 sk_buff_data_t old_tail = inst->skb->tail;
398
399 UDEBUG("entered\n");
400
401 nlh = NLMSG_PUT(inst->skb, 0, 0,
402 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
403 sizeof(struct nfgenmsg));
404 nfmsg = NLMSG_DATA(nlh);
405 nfmsg->nfgen_family = pf;
406 nfmsg->version = NFNETLINK_V0;
407 nfmsg->res_id = htons(inst->group_num);
408
409 pmsg.hw_protocol = skb->protocol;
410 pmsg.hook = hooknum;
411
412 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
413
414 if (prefix)
415 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
416
417 if (indev) {
418 tmp_uint = htonl(indev->ifindex);
419 #ifndef CONFIG_BRIDGE_NETFILTER
420 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
421 &tmp_uint);
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 NLA_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 NLA_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 NLA_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 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
442 sizeof(tmp_uint), &tmp_uint);
443 }
444 }
445 #endif
446 }
447
448 if (outdev) {
449 tmp_uint = htonl(outdev->ifindex);
450 #ifndef CONFIG_BRIDGE_NETFILTER
451 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
452 &tmp_uint);
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 NLA_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 NLA_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 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
468 sizeof(tmp_uint), &tmp_uint);
469 if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
470 tmp_uint =
471 htonl(skb->nf_bridge->physoutdev->ifindex);
472 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
473 sizeof(tmp_uint), &tmp_uint);
474 }
475 }
476 #endif
477 }
478
479 if (skb->mark) {
480 tmp_uint = htonl(skb->mark);
481 NLA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
482 }
483
484 if (indev && skb->dev) {
485 struct nfulnl_msg_packet_hw phw;
486 int len = dev_parse_header(skb, phw.hw_addr);
487 if (len > 0) {
488 phw.hw_addrlen = htons(len);
489 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
490 }
491 }
492
493 if (skb->tstamp.tv64) {
494 struct nfulnl_msg_packet_timestamp ts;
495 struct timeval tv = ktime_to_timeval(skb->tstamp);
496 ts.sec = cpu_to_be64(tv.tv_sec);
497 ts.usec = cpu_to_be64(tv.tv_usec);
498
499 NLA_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 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
507 /* need to unlock here since NLA_PUT may goto */
508 read_unlock_bh(&skb->sk->sk_callback_lock);
509 NLA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
510 } else
511 read_unlock_bh(&skb->sk->sk_callback_lock);
512 }
513
514 /* local sequence number */
515 if (inst->flags & NFULNL_CFG_F_SEQ) {
516 tmp_uint = htonl(inst->seq++);
517 NLA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
518 }
519 /* global sequence number */
520 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
521 tmp_uint = htonl(atomic_inc_return(&global_seq));
522 NLA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
523 }
524
525 if (data_len) {
526 struct nlattr *nla;
527 int size = nla_attr_size(data_len);
528
529 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
530 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
531 goto nlmsg_failure;
532 }
533
534 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
535 nla->nla_type = NFULA_PAYLOAD;
536 nla->nla_len = size;
537
538 if (skb_copy_bits(skb, 0, nla_data(nla), 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 nla_put_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 plen;
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 return;
589
590 plen = 0;
591 if (prefix)
592 plen = strlen(prefix) + 1;
593
594 /* FIXME: do we want to make the size calculation conditional based on
595 * what is actually present? way more branches and checks, but more
596 * memory efficient... */
597 size = NLMSG_ALIGN(sizeof(struct nfgenmsg))
598 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
599 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
600 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
601 #ifdef CONFIG_BRIDGE_NETFILTER
602 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
603 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
604 #endif
605 + nla_total_size(sizeof(u_int32_t)) /* mark */
606 + nla_total_size(sizeof(u_int32_t)) /* uid */
607 + nla_total_size(plen) /* prefix */
608 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
609 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
610
611 UDEBUG("initial size=%u\n", size);
612
613 spin_lock_bh(&inst->lock);
614
615 if (inst->flags & NFULNL_CFG_F_SEQ)
616 size += nla_total_size(sizeof(u_int32_t));
617 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
618 size += nla_total_size(sizeof(u_int32_t));
619
620 qthreshold = inst->qthreshold;
621 /* per-rule qthreshold overrides per-instance */
622 if (qthreshold > li->u.ulog.qthreshold)
623 qthreshold = li->u.ulog.qthreshold;
624
625 switch (inst->copy_mode) {
626 case NFULNL_COPY_META:
627 case NFULNL_COPY_NONE:
628 data_len = 0;
629 break;
630
631 case NFULNL_COPY_PACKET:
632 if (inst->copy_range == 0
633 || inst->copy_range > skb->len)
634 data_len = skb->len;
635 else
636 data_len = inst->copy_range;
637
638 size += nla_total_size(data_len);
639 UDEBUG("copy_packet, therefore size now %u\n", size);
640 break;
641
642 default:
643 goto unlock_and_release;
644 }
645
646 if (inst->skb &&
647 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
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_flush(inst);
653 }
654
655 if (!inst->skb) {
656 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
657 if (!inst->skb)
658 goto alloc_failure;
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, plen);
666
667 if (inst->qlen >= qthreshold)
668 __nfulnl_flush(inst);
669 /* timer_pending always called within inst->lock, so there
670 * is no chance of a race here */
671 else if (!timer_pending(&inst->timer)) {
672 instance_get(inst);
673 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
674 add_timer(&inst->timer);
675 }
676
677 unlock_and_release:
678 spin_unlock_bh(&inst->lock);
679 instance_put(inst);
680 return;
681
682 alloc_failure:
683 UDEBUG("error allocating skb\n");
684 /* FIXME: statistics */
685 goto unlock_and_release;
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->net == &init_net) &&
708 (n->pid == inst->peer_pid))
709 __instance_destroy(inst);
710 }
711 }
712 write_unlock_bh(&instances_lock);
713 }
714 return NOTIFY_DONE;
715 }
716
717 static struct notifier_block nfulnl_rtnl_notifier = {
718 .notifier_call = nfulnl_rcv_nl_event,
719 };
720
721 static int
722 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
723 struct nlmsghdr *nlh, struct nlattr *nfqa[])
724 {
725 return -ENOTSUPP;
726 }
727
728 static struct nf_logger nfulnl_logger = {
729 .name = "nfnetlink_log",
730 .logfn = &nfulnl_log_packet,
731 .me = THIS_MODULE,
732 };
733
734 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
735 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
736 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
737 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
738 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
739 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
740 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
741 };
742
743 static int
744 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
745 struct nlmsghdr *nlh, struct nlattr *nfula[])
746 {
747 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
748 u_int16_t group_num = ntohs(nfmsg->res_id);
749 struct nfulnl_instance *inst;
750 int ret = 0;
751
752 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
753
754 inst = instance_lookup_get(group_num);
755 if (nfula[NFULA_CFG_CMD]) {
756 u_int8_t pf = nfmsg->nfgen_family;
757 struct nfulnl_msg_config_cmd *cmd;
758 cmd = nla_data(nfula[NFULA_CFG_CMD]);
759 UDEBUG("found CFG_CMD for\n");
760
761 switch (cmd->command) {
762 case NFULNL_CFG_CMD_BIND:
763 if (inst) {
764 ret = -EBUSY;
765 goto out_put;
766 }
767
768 inst = instance_create(group_num,
769 NETLINK_CB(skb).pid);
770 if (!inst) {
771 ret = -EINVAL;
772 goto out;
773 }
774 break;
775 case NFULNL_CFG_CMD_UNBIND:
776 if (!inst) {
777 ret = -ENODEV;
778 goto out;
779 }
780
781 if (inst->peer_pid != NETLINK_CB(skb).pid) {
782 ret = -EPERM;
783 goto out_put;
784 }
785
786 instance_destroy(inst);
787 goto out;
788 case NFULNL_CFG_CMD_PF_BIND:
789 UDEBUG("registering log handler for pf=%u\n", pf);
790 ret = nf_log_register(pf, &nfulnl_logger);
791 break;
792 case NFULNL_CFG_CMD_PF_UNBIND:
793 UDEBUG("unregistering log handler for pf=%u\n", pf);
794 /* This is a bug and a feature. We cannot unregister
795 * other handlers, like nfnetlink_inst can */
796 nf_log_unregister_pf(pf);
797 break;
798 default:
799 ret = -EINVAL;
800 break;
801 }
802
803 if (!inst)
804 goto out;
805 } else {
806 if (!inst) {
807 UDEBUG("no config command, and no instance for "
808 "group=%u pid=%u =>ENOENT\n",
809 group_num, NETLINK_CB(skb).pid);
810 ret = -ENOENT;
811 goto out;
812 }
813
814 if (inst->peer_pid != NETLINK_CB(skb).pid) {
815 UDEBUG("no config command, and wrong pid\n");
816 ret = -EPERM;
817 goto out_put;
818 }
819 }
820
821 if (nfula[NFULA_CFG_MODE]) {
822 struct nfulnl_msg_config_mode *params;
823 params = nla_data(nfula[NFULA_CFG_MODE]);
824
825 nfulnl_set_mode(inst, params->copy_mode,
826 ntohl(params->copy_range));
827 }
828
829 if (nfula[NFULA_CFG_TIMEOUT]) {
830 __be32 timeout =
831 *(__be32 *)nla_data(nfula[NFULA_CFG_TIMEOUT]);
832
833 nfulnl_set_timeout(inst, ntohl(timeout));
834 }
835
836 if (nfula[NFULA_CFG_NLBUFSIZ]) {
837 __be32 nlbufsiz =
838 *(__be32 *)nla_data(nfula[NFULA_CFG_NLBUFSIZ]);
839
840 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
841 }
842
843 if (nfula[NFULA_CFG_QTHRESH]) {
844 __be32 qthresh =
845 *(__be32 *)nla_data(nfula[NFULA_CFG_QTHRESH]);
846
847 nfulnl_set_qthresh(inst, ntohl(qthresh));
848 }
849
850 if (nfula[NFULA_CFG_FLAGS]) {
851 __be16 flags =
852 *(__be16 *)nla_data(nfula[NFULA_CFG_FLAGS]);
853 nfulnl_set_flags(inst, ntohs(flags));
854 }
855
856 out_put:
857 instance_put(inst);
858 out:
859 return ret;
860 }
861
862 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
863 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
864 .attr_count = NFULA_MAX, },
865 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
866 .attr_count = NFULA_CFG_MAX,
867 .policy = nfula_cfg_policy },
868 };
869
870 static const 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 iter_state *st)
883 {
884 if (!st)
885 return NULL;
886
887 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
888 if (!hlist_empty(&instance_table[st->bucket]))
889 return instance_table[st->bucket].first;
890 }
891 return NULL;
892 }
893
894 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
895 {
896 h = h->next;
897 while (!h) {
898 if (++st->bucket >= INSTANCE_BUCKETS)
899 return NULL;
900
901 h = instance_table[st->bucket].first;
902 }
903 return h;
904 }
905
906 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
907 {
908 struct hlist_node *head;
909 head = get_first(st);
910
911 if (head)
912 while (pos && (head = get_next(st, head)))
913 pos--;
914 return pos ? NULL : head;
915 }
916
917 static void *seq_start(struct seq_file *seq, loff_t *pos)
918 {
919 read_lock_bh(&instances_lock);
920 return get_idx(seq->private, *pos);
921 }
922
923 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
924 {
925 (*pos)++;
926 return get_next(s->private, v);
927 }
928
929 static void seq_stop(struct seq_file *s, void *v)
930 {
931 read_unlock_bh(&instances_lock);
932 }
933
934 static int seq_show(struct seq_file *s, void *v)
935 {
936 const struct nfulnl_instance *inst = v;
937
938 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
939 inst->group_num,
940 inst->peer_pid, inst->qlen,
941 inst->copy_mode, inst->copy_range,
942 inst->flushtimeout, atomic_read(&inst->use));
943 }
944
945 static const struct seq_operations nful_seq_ops = {
946 .start = seq_start,
947 .next = seq_next,
948 .stop = seq_stop,
949 .show = seq_show,
950 };
951
952 static int nful_open(struct inode *inode, struct file *file)
953 {
954 return seq_open_private(file, &nful_seq_ops,
955 sizeof(struct iter_state));
956 }
957
958 static const struct file_operations nful_file_ops = {
959 .owner = THIS_MODULE,
960 .open = nful_open,
961 .read = seq_read,
962 .llseek = seq_lseek,
963 .release = seq_release_private,
964 };
965
966 #endif /* PROC_FS */
967
968 static int __init nfnetlink_log_init(void)
969 {
970 int i, status = -ENOMEM;
971 #ifdef CONFIG_PROC_FS
972 struct proc_dir_entry *proc_nful;
973 #endif
974
975 for (i = 0; i < INSTANCE_BUCKETS; i++)
976 INIT_HLIST_HEAD(&instance_table[i]);
977
978 /* it's not really all that important to have a random value, so
979 * we can do this from the init function, even if there hasn't
980 * been that much entropy yet */
981 get_random_bytes(&hash_init, sizeof(hash_init));
982
983 netlink_register_notifier(&nfulnl_rtnl_notifier);
984 status = nfnetlink_subsys_register(&nfulnl_subsys);
985 if (status < 0) {
986 printk(KERN_ERR "log: failed to create netlink socket\n");
987 goto cleanup_netlink_notifier;
988 }
989
990 #ifdef CONFIG_PROC_FS
991 proc_nful = create_proc_entry("nfnetlink_log", 0440,
992 proc_net_netfilter);
993 if (!proc_nful)
994 goto cleanup_subsys;
995 proc_nful->proc_fops = &nful_file_ops;
996 #endif
997 return status;
998
999 #ifdef CONFIG_PROC_FS
1000 cleanup_subsys:
1001 nfnetlink_subsys_unregister(&nfulnl_subsys);
1002 #endif
1003 cleanup_netlink_notifier:
1004 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1005 return status;
1006 }
1007
1008 static void __exit nfnetlink_log_fini(void)
1009 {
1010 nf_log_unregister(&nfulnl_logger);
1011 #ifdef CONFIG_PROC_FS
1012 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1013 #endif
1014 nfnetlink_subsys_unregister(&nfulnl_subsys);
1015 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1016 }
1017
1018 MODULE_DESCRIPTION("netfilter userspace logging");
1019 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1020 MODULE_LICENSE("GPL");
1021 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1022
1023 module_init(nfnetlink_log_init);
1024 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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