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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[cris-mirror.git] / net / netfilter / nfnetlink_log.c
blob985e9b76c9162f253f839401a40b1f1eb51dc364
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 <linux/slab.h>
32 #include <net/sock.h>
33 #include <net/netfilter/nf_log.h>
34 #include <net/netfilter/nfnetlink_log.h>
35
36 #include <asm/atomic.h>
37
38 #ifdef CONFIG_BRIDGE_NETFILTER
39 #include "../bridge/br_private.h"
40 #endif
41
42 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
43 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
44 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
45 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
46
47 #define PRINTR(x, args...) do { if (net_ratelimit()) \
48 printk(x, ## args); } while (0);
49
50 struct nfulnl_instance {
51 struct hlist_node hlist; /* global list of instances */
52 spinlock_t lock;
53 atomic_t use; /* use count */
54
55 unsigned int qlen; /* number of nlmsgs in skb */
56 struct sk_buff *skb; /* pre-allocatd skb */
57 struct timer_list timer;
58 int peer_pid; /* PID of the peer process */
59
60 /* configurable parameters */
61 unsigned int flushtimeout; /* timeout until queue flush */
62 unsigned int nlbufsiz; /* netlink buffer allocation size */
63 unsigned int qthreshold; /* threshold of the queue */
64 u_int32_t copy_range;
65 u_int32_t seq; /* instance-local sequential counter */
66 u_int16_t group_num; /* number of this queue */
67 u_int16_t flags;
68 u_int8_t copy_mode;
69 struct rcu_head rcu;
70 };
71
72 static DEFINE_SPINLOCK(instances_lock);
73 static atomic_t global_seq;
74
75 #define INSTANCE_BUCKETS 16
76 static struct hlist_head instance_table[INSTANCE_BUCKETS];
77 static unsigned int hash_init;
78
79 static inline u_int8_t instance_hashfn(u_int16_t group_num)
80 {
81 return ((group_num & 0xff) % INSTANCE_BUCKETS);
82 }
83
84 static struct nfulnl_instance *
85 __instance_lookup(u_int16_t group_num)
86 {
87 struct hlist_head *head;
88 struct hlist_node *pos;
89 struct nfulnl_instance *inst;
90
91 head = &instance_table[instance_hashfn(group_num)];
92 hlist_for_each_entry_rcu(inst, pos, head, hlist) {
93 if (inst->group_num == group_num)
94 return inst;
95 }
96 return NULL;
97 }
98
99 static inline void
100 instance_get(struct nfulnl_instance *inst)
101 {
102 atomic_inc(&inst->use);
103 }
104
105 static struct nfulnl_instance *
106 instance_lookup_get(u_int16_t group_num)
107 {
108 struct nfulnl_instance *inst;
109
110 rcu_read_lock_bh();
111 inst = __instance_lookup(group_num);
112 if (inst && !atomic_inc_not_zero(&inst->use))
113 inst = NULL;
114 rcu_read_unlock_bh();
115
116 return inst;
117 }
118
119 static void nfulnl_instance_free_rcu(struct rcu_head *head)
120 {
121 kfree(container_of(head, struct nfulnl_instance, rcu));
122 module_put(THIS_MODULE);
123 }
124
125 static void
126 instance_put(struct nfulnl_instance *inst)
127 {
128 if (inst && atomic_dec_and_test(&inst->use))
129 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
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 int err;
139
140 spin_lock_bh(&instances_lock);
141 if (__instance_lookup(group_num)) {
142 err = -EEXIST;
143 goto out_unlock;
144 }
145
146 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
147 if (!inst) {
148 err = -ENOMEM;
149 goto out_unlock;
150 }
151
152 if (!try_module_get(THIS_MODULE)) {
153 kfree(inst);
154 err = -EAGAIN;
155 goto out_unlock;
156 }
157
158 INIT_HLIST_NODE(&inst->hlist);
159 spin_lock_init(&inst->lock);
160 /* needs to be two, since we _put() after creation */
161 atomic_set(&inst->use, 2);
162
163 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
164
165 inst->peer_pid = pid;
166 inst->group_num = group_num;
167
168 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
169 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
170 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
171 inst->copy_mode = NFULNL_COPY_PACKET;
172 inst->copy_range = NFULNL_COPY_RANGE_MAX;
173
174 hlist_add_head_rcu(&inst->hlist,
175 &instance_table[instance_hashfn(group_num)]);
176
177 spin_unlock_bh(&instances_lock);
178
179 return inst;
180
181 out_unlock:
182 spin_unlock_bh(&instances_lock);
183 return ERR_PTR(err);
184 }
185
186 static void __nfulnl_flush(struct nfulnl_instance *inst);
187
188 /* called with BH disabled */
189 static void
190 __instance_destroy(struct nfulnl_instance *inst)
191 {
192 /* first pull it out of the global list */
193 hlist_del_rcu(&inst->hlist);
194
195 /* then flush all pending packets from skb */
196
197 spin_lock(&inst->lock);
198
199 /* lockless readers wont be able to use us */
200 inst->copy_mode = NFULNL_COPY_DISABLED;
201
202 if (inst->skb)
203 __nfulnl_flush(inst);
204 spin_unlock(&inst->lock);
205
206 /* and finally put the refcount */
207 instance_put(inst);
208 }
209
210 static inline void
211 instance_destroy(struct nfulnl_instance *inst)
212 {
213 spin_lock_bh(&instances_lock);
214 __instance_destroy(inst);
215 spin_unlock_bh(&instances_lock);
216 }
217
218 static int
219 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
220 unsigned int range)
221 {
222 int status = 0;
223
224 spin_lock_bh(&inst->lock);
225
226 switch (mode) {
227 case NFULNL_COPY_NONE:
228 case NFULNL_COPY_META:
229 inst->copy_mode = mode;
230 inst->copy_range = 0;
231 break;
232
233 case NFULNL_COPY_PACKET:
234 inst->copy_mode = mode;
235 inst->copy_range = min_t(unsigned int,
236 range, NFULNL_COPY_RANGE_MAX);
237 break;
238
239 default:
240 status = -EINVAL;
241 break;
242 }
243
244 spin_unlock_bh(&inst->lock);
245
246 return status;
247 }
248
249 static int
250 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
251 {
252 int status;
253
254 spin_lock_bh(&inst->lock);
255 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
256 status = -ERANGE;
257 else if (nlbufsiz > 131072)
258 status = -ERANGE;
259 else {
260 inst->nlbufsiz = nlbufsiz;
261 status = 0;
262 }
263 spin_unlock_bh(&inst->lock);
264
265 return status;
266 }
267
268 static int
269 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
270 {
271 spin_lock_bh(&inst->lock);
272 inst->flushtimeout = timeout;
273 spin_unlock_bh(&inst->lock);
274
275 return 0;
276 }
277
278 static int
279 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
280 {
281 spin_lock_bh(&inst->lock);
282 inst->qthreshold = qthresh;
283 spin_unlock_bh(&inst->lock);
284
285 return 0;
286 }
287
288 static int
289 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
290 {
291 spin_lock_bh(&inst->lock);
292 inst->flags = flags;
293 spin_unlock_bh(&inst->lock);
294
295 return 0;
296 }
297
298 static struct sk_buff *
299 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
300 {
301 struct sk_buff *skb;
302 unsigned int n;
303
304 /* alloc skb which should be big enough for a whole multipart
305 * message. WARNING: has to be <= 128k due to slab restrictions */
306
307 n = max(inst_size, pkt_size);
308 skb = alloc_skb(n, GFP_ATOMIC);
309 if (!skb) {
310 pr_notice("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
311 inst_size);
312
313 if (n > pkt_size) {
314 /* try to allocate only as much as we need for current
315 * packet */
316
317 skb = alloc_skb(pkt_size, GFP_ATOMIC);
318 if (!skb)
319 pr_err("nfnetlink_log: can't even alloc %u "
320 "bytes\n", pkt_size);
321 }
322 }
323
324 return skb;
325 }
326
327 static int
328 __nfulnl_send(struct nfulnl_instance *inst)
329 {
330 int status = -1;
331
332 if (inst->qlen > 1)
333 NLMSG_PUT(inst->skb, 0, 0,
334 NLMSG_DONE,
335 sizeof(struct nfgenmsg));
336
337 status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid,
338 MSG_DONTWAIT);
339
340 inst->qlen = 0;
341 inst->skb = NULL;
342
343 nlmsg_failure:
344 return status;
345 }
346
347 static void
348 __nfulnl_flush(struct nfulnl_instance *inst)
349 {
350 /* timer holds a reference */
351 if (del_timer(&inst->timer))
352 instance_put(inst);
353 if (inst->skb)
354 __nfulnl_send(inst);
355 }
356
357 static void
358 nfulnl_timer(unsigned long data)
359 {
360 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
361
362 spin_lock_bh(&inst->lock);
363 if (inst->skb)
364 __nfulnl_send(inst);
365 spin_unlock_bh(&inst->lock);
366 instance_put(inst);
367 }
368
369 /* This is an inline function, we don't really care about a long
370 * list of arguments */
371 static inline int
372 __build_packet_message(struct nfulnl_instance *inst,
373 const struct sk_buff *skb,
374 unsigned int data_len,
375 u_int8_t pf,
376 unsigned int hooknum,
377 const struct net_device *indev,
378 const struct net_device *outdev,
379 const char *prefix, unsigned int plen)
380 {
381 struct nfulnl_msg_packet_hdr pmsg;
382 struct nlmsghdr *nlh;
383 struct nfgenmsg *nfmsg;
384 __be32 tmp_uint;
385 sk_buff_data_t old_tail = inst->skb->tail;
386
387 nlh = NLMSG_PUT(inst->skb, 0, 0,
388 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
389 sizeof(struct nfgenmsg));
390 nfmsg = NLMSG_DATA(nlh);
391 nfmsg->nfgen_family = pf;
392 nfmsg->version = NFNETLINK_V0;
393 nfmsg->res_id = htons(inst->group_num);
394
395 pmsg.hw_protocol = skb->protocol;
396 pmsg.hook = hooknum;
397
398 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
399
400 if (prefix)
401 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
402
403 if (indev) {
404 #ifndef CONFIG_BRIDGE_NETFILTER
405 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
406 htonl(indev->ifindex));
407 #else
408 if (pf == PF_BRIDGE) {
409 /* Case 1: outdev is physical input device, we need to
410 * look for bridge group (when called from
411 * netfilter_bridge) */
412 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
413 htonl(indev->ifindex));
414 /* this is the bridge group "brX" */
415 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
416 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
417 htonl(br_port_get_rcu(indev)->br->dev->ifindex));
418 } else {
419 /* Case 2: indev is bridge group, we need to look for
420 * physical device (when called from ipv4) */
421 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
422 htonl(indev->ifindex));
423 if (skb->nf_bridge && skb->nf_bridge->physindev)
424 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
425 htonl(skb->nf_bridge->physindev->ifindex));
426 }
427 #endif
428 }
429
430 if (outdev) {
431 tmp_uint = htonl(outdev->ifindex);
432 #ifndef CONFIG_BRIDGE_NETFILTER
433 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
434 htonl(outdev->ifindex));
435 #else
436 if (pf == PF_BRIDGE) {
437 /* Case 1: outdev is physical output device, we need to
438 * look for bridge group (when called from
439 * netfilter_bridge) */
440 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
441 htonl(outdev->ifindex));
442 /* this is the bridge group "brX" */
443 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
444 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
445 htonl(br_port_get_rcu(outdev)->br->dev->ifindex));
446 } else {
447 /* Case 2: indev is a bridge group, we need to look
448 * for physical device (when called from ipv4) */
449 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
450 htonl(outdev->ifindex));
451 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
452 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
453 htonl(skb->nf_bridge->physoutdev->ifindex));
454 }
455 #endif
456 }
457
458 if (skb->mark)
459 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
460
461 if (indev && skb->dev) {
462 struct nfulnl_msg_packet_hw phw;
463 int len = dev_parse_header(skb, phw.hw_addr);
464 if (len > 0) {
465 phw.hw_addrlen = htons(len);
466 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
467 }
468 }
469
470 if (indev && skb_mac_header_was_set(skb)) {
471 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
472 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
473 htons(skb->dev->hard_header_len));
474 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
475 skb_mac_header(skb));
476 }
477
478 if (skb->tstamp.tv64) {
479 struct nfulnl_msg_packet_timestamp ts;
480 struct timeval tv = ktime_to_timeval(skb->tstamp);
481 ts.sec = cpu_to_be64(tv.tv_sec);
482 ts.usec = cpu_to_be64(tv.tv_usec);
483
484 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
485 }
486
487 /* UID */
488 if (skb->sk) {
489 read_lock_bh(&skb->sk->sk_callback_lock);
490 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
491 struct file *file = skb->sk->sk_socket->file;
492 __be32 uid = htonl(file->f_cred->fsuid);
493 __be32 gid = htonl(file->f_cred->fsgid);
494 /* need to unlock here since NLA_PUT may goto */
495 read_unlock_bh(&skb->sk->sk_callback_lock);
496 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
497 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
498 } else
499 read_unlock_bh(&skb->sk->sk_callback_lock);
500 }
501
502 /* local sequence number */
503 if (inst->flags & NFULNL_CFG_F_SEQ)
504 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
505
506 /* global sequence number */
507 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
508 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
509 htonl(atomic_inc_return(&global_seq)));
510
511 if (data_len) {
512 struct nlattr *nla;
513 int size = nla_attr_size(data_len);
514
515 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
516 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
517 goto nlmsg_failure;
518 }
519
520 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
521 nla->nla_type = NFULA_PAYLOAD;
522 nla->nla_len = size;
523
524 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
525 BUG();
526 }
527
528 nlh->nlmsg_len = inst->skb->tail - old_tail;
529 return 0;
530
531 nlmsg_failure:
532 nla_put_failure:
533 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
534 return -1;
535 }
536
537 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
538
539 static struct nf_loginfo default_loginfo = {
540 .type = NF_LOG_TYPE_ULOG,
541 .u = {
542 .ulog = {
543 .copy_len = 0xffff,
544 .group = 0,
545 .qthreshold = 1,
546 },
547 },
548 };
549
550 /* log handler for internal netfilter logging api */
551 void
552 nfulnl_log_packet(u_int8_t pf,
553 unsigned int hooknum,
554 const struct sk_buff *skb,
555 const struct net_device *in,
556 const struct net_device *out,
557 const struct nf_loginfo *li_user,
558 const char *prefix)
559 {
560 unsigned int size, data_len;
561 struct nfulnl_instance *inst;
562 const struct nf_loginfo *li;
563 unsigned int qthreshold;
564 unsigned int plen;
565
566 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
567 li = li_user;
568 else
569 li = &default_loginfo;
570
571 inst = instance_lookup_get(li->u.ulog.group);
572 if (!inst)
573 return;
574
575 plen = 0;
576 if (prefix)
577 plen = strlen(prefix) + 1;
578
579 /* FIXME: do we want to make the size calculation conditional based on
580 * what is actually present? way more branches and checks, but more
581 * memory efficient... */
582 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
583 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
584 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
585 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
586 #ifdef CONFIG_BRIDGE_NETFILTER
587 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
588 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
589 #endif
590 + nla_total_size(sizeof(u_int32_t)) /* mark */
591 + nla_total_size(sizeof(u_int32_t)) /* uid */
592 + nla_total_size(sizeof(u_int32_t)) /* gid */
593 + nla_total_size(plen) /* prefix */
594 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
595 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
596
597 if (in && skb_mac_header_was_set(skb)) {
598 size += nla_total_size(skb->dev->hard_header_len)
599 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
600 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
601 }
602
603 spin_lock_bh(&inst->lock);
604
605 if (inst->flags & NFULNL_CFG_F_SEQ)
606 size += nla_total_size(sizeof(u_int32_t));
607 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
608 size += nla_total_size(sizeof(u_int32_t));
609
610 qthreshold = inst->qthreshold;
611 /* per-rule qthreshold overrides per-instance */
612 if (li->u.ulog.qthreshold)
613 if (qthreshold > li->u.ulog.qthreshold)
614 qthreshold = li->u.ulog.qthreshold;
615
616
617 switch (inst->copy_mode) {
618 case NFULNL_COPY_META:
619 case NFULNL_COPY_NONE:
620 data_len = 0;
621 break;
622
623 case NFULNL_COPY_PACKET:
624 if (inst->copy_range == 0
625 || inst->copy_range > skb->len)
626 data_len = skb->len;
627 else
628 data_len = inst->copy_range;
629
630 size += nla_total_size(data_len);
631 break;
632
633 case NFULNL_COPY_DISABLED:
634 default:
635 goto unlock_and_release;
636 }
637
638 if (inst->skb &&
639 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
640 /* either the queue len is too high or we don't have
641 * enough room in the skb left. flush to userspace. */
642 __nfulnl_flush(inst);
643 }
644
645 if (!inst->skb) {
646 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
647 if (!inst->skb)
648 goto alloc_failure;
649 }
650
651 inst->qlen++;
652
653 __build_packet_message(inst, skb, data_len, pf,
654 hooknum, in, out, prefix, plen);
655
656 if (inst->qlen >= qthreshold)
657 __nfulnl_flush(inst);
658 /* timer_pending always called within inst->lock, so there
659 * is no chance of a race here */
660 else if (!timer_pending(&inst->timer)) {
661 instance_get(inst);
662 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
663 add_timer(&inst->timer);
664 }
665
666 unlock_and_release:
667 spin_unlock_bh(&inst->lock);
668 instance_put(inst);
669 return;
670
671 alloc_failure:
672 /* FIXME: statistics */
673 goto unlock_and_release;
674 }
675 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
676
677 static int
678 nfulnl_rcv_nl_event(struct notifier_block *this,
679 unsigned long event, void *ptr)
680 {
681 struct netlink_notify *n = ptr;
682
683 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
684 int i;
685
686 /* destroy all instances for this pid */
687 spin_lock_bh(&instances_lock);
688 for (i = 0; i < INSTANCE_BUCKETS; i++) {
689 struct hlist_node *tmp, *t2;
690 struct nfulnl_instance *inst;
691 struct hlist_head *head = &instance_table[i];
692
693 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
694 if ((net_eq(n->net, &init_net)) &&
695 (n->pid == inst->peer_pid))
696 __instance_destroy(inst);
697 }
698 }
699 spin_unlock_bh(&instances_lock);
700 }
701 return NOTIFY_DONE;
702 }
703
704 static struct notifier_block nfulnl_rtnl_notifier = {
705 .notifier_call = nfulnl_rcv_nl_event,
706 };
707
708 static int
709 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
710 const struct nlmsghdr *nlh,
711 const struct nlattr * const nfqa[])
712 {
713 return -ENOTSUPP;
714 }
715
716 static struct nf_logger nfulnl_logger __read_mostly = {
717 .name = "nfnetlink_log",
718 .logfn = &nfulnl_log_packet,
719 .me = THIS_MODULE,
720 };
721
722 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
723 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
724 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
725 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
726 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
727 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
728 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
729 };
730
731 static int
732 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
733 const struct nlmsghdr *nlh,
734 const struct nlattr * const nfula[])
735 {
736 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
737 u_int16_t group_num = ntohs(nfmsg->res_id);
738 struct nfulnl_instance *inst;
739 struct nfulnl_msg_config_cmd *cmd = NULL;
740 int ret = 0;
741
742 if (nfula[NFULA_CFG_CMD]) {
743 u_int8_t pf = nfmsg->nfgen_family;
744 cmd = nla_data(nfula[NFULA_CFG_CMD]);
745
746 /* Commands without queue context */
747 switch (cmd->command) {
748 case NFULNL_CFG_CMD_PF_BIND:
749 return nf_log_bind_pf(pf, &nfulnl_logger);
750 case NFULNL_CFG_CMD_PF_UNBIND:
751 nf_log_unbind_pf(pf);
752 return 0;
753 }
754 }
755
756 inst = instance_lookup_get(group_num);
757 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
758 ret = -EPERM;
759 goto out_put;
760 }
761
762 if (cmd != NULL) {
763 switch (cmd->command) {
764 case NFULNL_CFG_CMD_BIND:
765 if (inst) {
766 ret = -EBUSY;
767 goto out_put;
768 }
769
770 inst = instance_create(group_num,
771 NETLINK_CB(skb).pid);
772 if (IS_ERR(inst)) {
773 ret = PTR_ERR(inst);
774 goto out;
775 }
776 break;
777 case NFULNL_CFG_CMD_UNBIND:
778 if (!inst) {
779 ret = -ENODEV;
780 goto out;
781 }
782
783 instance_destroy(inst);
784 goto out_put;
785 default:
786 ret = -ENOTSUPP;
787 break;
788 }
789 }
790
791 if (nfula[NFULA_CFG_MODE]) {
792 struct nfulnl_msg_config_mode *params;
793 params = nla_data(nfula[NFULA_CFG_MODE]);
794
795 if (!inst) {
796 ret = -ENODEV;
797 goto out;
798 }
799 nfulnl_set_mode(inst, params->copy_mode,
800 ntohl(params->copy_range));
801 }
802
803 if (nfula[NFULA_CFG_TIMEOUT]) {
804 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
805
806 if (!inst) {
807 ret = -ENODEV;
808 goto out;
809 }
810 nfulnl_set_timeout(inst, ntohl(timeout));
811 }
812
813 if (nfula[NFULA_CFG_NLBUFSIZ]) {
814 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
815
816 if (!inst) {
817 ret = -ENODEV;
818 goto out;
819 }
820 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
821 }
822
823 if (nfula[NFULA_CFG_QTHRESH]) {
824 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
825
826 if (!inst) {
827 ret = -ENODEV;
828 goto out;
829 }
830 nfulnl_set_qthresh(inst, ntohl(qthresh));
831 }
832
833 if (nfula[NFULA_CFG_FLAGS]) {
834 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
835
836 if (!inst) {
837 ret = -ENODEV;
838 goto out;
839 }
840 nfulnl_set_flags(inst, ntohs(flags));
841 }
842
843 out_put:
844 instance_put(inst);
845 out:
846 return ret;
847 }
848
849 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
850 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
851 .attr_count = NFULA_MAX, },
852 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
853 .attr_count = NFULA_CFG_MAX,
854 .policy = nfula_cfg_policy },
855 };
856
857 static const struct nfnetlink_subsystem nfulnl_subsys = {
858 .name = "log",
859 .subsys_id = NFNL_SUBSYS_ULOG,
860 .cb_count = NFULNL_MSG_MAX,
861 .cb = nfulnl_cb,
862 };
863
864 #ifdef CONFIG_PROC_FS
865 struct iter_state {
866 unsigned int bucket;
867 };
868
869 static struct hlist_node *get_first(struct iter_state *st)
870 {
871 if (!st)
872 return NULL;
873
874 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
875 if (!hlist_empty(&instance_table[st->bucket]))
876 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
877 }
878 return NULL;
879 }
880
881 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
882 {
883 h = rcu_dereference_bh(hlist_next_rcu(h));
884 while (!h) {
885 if (++st->bucket >= INSTANCE_BUCKETS)
886 return NULL;
887
888 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
889 }
890 return h;
891 }
892
893 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
894 {
895 struct hlist_node *head;
896 head = get_first(st);
897
898 if (head)
899 while (pos && (head = get_next(st, head)))
900 pos--;
901 return pos ? NULL : head;
902 }
903
904 static void *seq_start(struct seq_file *seq, loff_t *pos)
905 __acquires(rcu_bh)
906 {
907 rcu_read_lock_bh();
908 return get_idx(seq->private, *pos);
909 }
910
911 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
912 {
913 (*pos)++;
914 return get_next(s->private, v);
915 }
916
917 static void seq_stop(struct seq_file *s, void *v)
918 __releases(rcu_bh)
919 {
920 rcu_read_unlock_bh();
921 }
922
923 static int seq_show(struct seq_file *s, void *v)
924 {
925 const struct nfulnl_instance *inst = v;
926
927 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
928 inst->group_num,
929 inst->peer_pid, inst->qlen,
930 inst->copy_mode, inst->copy_range,
931 inst->flushtimeout, atomic_read(&inst->use));
932 }
933
934 static const struct seq_operations nful_seq_ops = {
935 .start = seq_start,
936 .next = seq_next,
937 .stop = seq_stop,
938 .show = seq_show,
939 };
940
941 static int nful_open(struct inode *inode, struct file *file)
942 {
943 return seq_open_private(file, &nful_seq_ops,
944 sizeof(struct iter_state));
945 }
946
947 static const struct file_operations nful_file_ops = {
948 .owner = THIS_MODULE,
949 .open = nful_open,
950 .read = seq_read,
951 .llseek = seq_lseek,
952 .release = seq_release_private,
953 };
954
955 #endif /* PROC_FS */
956
957 static int __init nfnetlink_log_init(void)
958 {
959 int i, status = -ENOMEM;
960
961 for (i = 0; i < INSTANCE_BUCKETS; i++)
962 INIT_HLIST_HEAD(&instance_table[i]);
963
964 /* it's not really all that important to have a random value, so
965 * we can do this from the init function, even if there hasn't
966 * been that much entropy yet */
967 get_random_bytes(&hash_init, sizeof(hash_init));
968
969 netlink_register_notifier(&nfulnl_rtnl_notifier);
970 status = nfnetlink_subsys_register(&nfulnl_subsys);
971 if (status < 0) {
972 printk(KERN_ERR "log: failed to create netlink socket\n");
973 goto cleanup_netlink_notifier;
974 }
975
976 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
977 if (status < 0) {
978 printk(KERN_ERR "log: failed to register logger\n");
979 goto cleanup_subsys;
980 }
981
982 #ifdef CONFIG_PROC_FS
983 if (!proc_create("nfnetlink_log", 0440,
984 proc_net_netfilter, &nful_file_ops))
985 goto cleanup_logger;
986 #endif
987 return status;
988
989 #ifdef CONFIG_PROC_FS
990 cleanup_logger:
991 nf_log_unregister(&nfulnl_logger);
992 #endif
993 cleanup_subsys:
994 nfnetlink_subsys_unregister(&nfulnl_subsys);
995 cleanup_netlink_notifier:
996 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
997 return status;
998 }
999
1000 static void __exit nfnetlink_log_fini(void)
1001 {
1002 nf_log_unregister(&nfulnl_logger);
1003 #ifdef CONFIG_PROC_FS
1004 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1005 #endif
1006 nfnetlink_subsys_unregister(&nfulnl_subsys);
1007 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1008 }
1009
1010 MODULE_DESCRIPTION("netfilter userspace logging");
1011 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1012 MODULE_LICENSE("GPL");
1013 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1014
1015 module_init(nfnetlink_log_init);
1016 module_exit(nfnetlink_log_fini);
CRIS linux kernel tree