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Add linux-next specific files for 20110421
[linux-2.6/next.git] / net / netfilter / nfnetlink_log.c
blobe0ee010935e7008a8730b2c87a2c9c689226fb8a
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 sk_buff_data_t old_tail = inst->skb->tail;
385
386 nlh = NLMSG_PUT(inst->skb, 0, 0,
387 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
388 sizeof(struct nfgenmsg));
389 nfmsg = NLMSG_DATA(nlh);
390 nfmsg->nfgen_family = pf;
391 nfmsg->version = NFNETLINK_V0;
392 nfmsg->res_id = htons(inst->group_num);
393
394 pmsg.hw_protocol = skb->protocol;
395 pmsg.hook = hooknum;
396
397 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
398
399 if (prefix)
400 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
401
402 if (indev) {
403 #ifndef CONFIG_BRIDGE_NETFILTER
404 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
405 htonl(indev->ifindex));
406 #else
407 if (pf == PF_BRIDGE) {
408 /* Case 1: outdev is physical input device, we need to
409 * look for bridge group (when called from
410 * netfilter_bridge) */
411 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
412 htonl(indev->ifindex));
413 /* this is the bridge group "brX" */
414 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
415 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
416 htonl(br_port_get_rcu(indev)->br->dev->ifindex));
417 } else {
418 /* Case 2: indev is bridge group, we need to look for
419 * physical device (when called from ipv4) */
420 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
421 htonl(indev->ifindex));
422 if (skb->nf_bridge && skb->nf_bridge->physindev)
423 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
424 htonl(skb->nf_bridge->physindev->ifindex));
425 }
426 #endif
427 }
428
429 if (outdev) {
430 #ifndef CONFIG_BRIDGE_NETFILTER
431 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
432 htonl(outdev->ifindex));
433 #else
434 if (pf == PF_BRIDGE) {
435 /* Case 1: outdev is physical output device, we need to
436 * look for bridge group (when called from
437 * netfilter_bridge) */
438 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
439 htonl(outdev->ifindex));
440 /* this is the bridge group "brX" */
441 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
442 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
443 htonl(br_port_get_rcu(outdev)->br->dev->ifindex));
444 } else {
445 /* Case 2: indev is a bridge group, we need to look
446 * for physical device (when called from ipv4) */
447 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
448 htonl(outdev->ifindex));
449 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
450 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
451 htonl(skb->nf_bridge->physoutdev->ifindex));
452 }
453 #endif
454 }
455
456 if (skb->mark)
457 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
458
459 if (indev && skb->dev) {
460 struct nfulnl_msg_packet_hw phw;
461 int len = dev_parse_header(skb, phw.hw_addr);
462 if (len > 0) {
463 phw.hw_addrlen = htons(len);
464 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
465 }
466 }
467
468 if (indev && skb_mac_header_was_set(skb)) {
469 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
470 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
471 htons(skb->dev->hard_header_len));
472 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
473 skb_mac_header(skb));
474 }
475
476 if (skb->tstamp.tv64) {
477 struct nfulnl_msg_packet_timestamp ts;
478 struct timeval tv = ktime_to_timeval(skb->tstamp);
479 ts.sec = cpu_to_be64(tv.tv_sec);
480 ts.usec = cpu_to_be64(tv.tv_usec);
481
482 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
483 }
484
485 /* UID */
486 if (skb->sk) {
487 read_lock_bh(&skb->sk->sk_callback_lock);
488 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
489 struct file *file = skb->sk->sk_socket->file;
490 __be32 uid = htonl(file->f_cred->fsuid);
491 __be32 gid = htonl(file->f_cred->fsgid);
492 /* need to unlock here since NLA_PUT may goto */
493 read_unlock_bh(&skb->sk->sk_callback_lock);
494 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
495 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
496 } else
497 read_unlock_bh(&skb->sk->sk_callback_lock);
498 }
499
500 /* local sequence number */
501 if (inst->flags & NFULNL_CFG_F_SEQ)
502 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
503
504 /* global sequence number */
505 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
506 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
507 htonl(atomic_inc_return(&global_seq)));
508
509 if (data_len) {
510 struct nlattr *nla;
511 int size = nla_attr_size(data_len);
512
513 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
514 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
515 goto nlmsg_failure;
516 }
517
518 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
519 nla->nla_type = NFULA_PAYLOAD;
520 nla->nla_len = size;
521
522 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
523 BUG();
524 }
525
526 nlh->nlmsg_len = inst->skb->tail - old_tail;
527 return 0;
528
529 nlmsg_failure:
530 nla_put_failure:
531 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
532 return -1;
533 }
534
535 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
536
537 static struct nf_loginfo default_loginfo = {
538 .type = NF_LOG_TYPE_ULOG,
539 .u = {
540 .ulog = {
541 .copy_len = 0xffff,
542 .group = 0,
543 .qthreshold = 1,
544 },
545 },
546 };
547
548 /* log handler for internal netfilter logging api */
549 void
550 nfulnl_log_packet(u_int8_t pf,
551 unsigned int hooknum,
552 const struct sk_buff *skb,
553 const struct net_device *in,
554 const struct net_device *out,
555 const struct nf_loginfo *li_user,
556 const char *prefix)
557 {
558 unsigned int size, data_len;
559 struct nfulnl_instance *inst;
560 const struct nf_loginfo *li;
561 unsigned int qthreshold;
562 unsigned int plen;
563
564 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
565 li = li_user;
566 else
567 li = &default_loginfo;
568
569 inst = instance_lookup_get(li->u.ulog.group);
570 if (!inst)
571 return;
572
573 plen = 0;
574 if (prefix)
575 plen = strlen(prefix) + 1;
576
577 /* FIXME: do we want to make the size calculation conditional based on
578 * what is actually present? way more branches and checks, but more
579 * memory efficient... */
580 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
581 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
582 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
583 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
584 #ifdef CONFIG_BRIDGE_NETFILTER
585 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
586 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
587 #endif
588 + nla_total_size(sizeof(u_int32_t)) /* mark */
589 + nla_total_size(sizeof(u_int32_t)) /* uid */
590 + nla_total_size(sizeof(u_int32_t)) /* gid */
591 + nla_total_size(plen) /* prefix */
592 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
593 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
594
595 if (in && skb_mac_header_was_set(skb)) {
596 size += nla_total_size(skb->dev->hard_header_len)
597 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
598 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
599 }
600
601 spin_lock_bh(&inst->lock);
602
603 if (inst->flags & NFULNL_CFG_F_SEQ)
604 size += nla_total_size(sizeof(u_int32_t));
605 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
606 size += nla_total_size(sizeof(u_int32_t));
607
608 qthreshold = inst->qthreshold;
609 /* per-rule qthreshold overrides per-instance */
610 if (li->u.ulog.qthreshold)
611 if (qthreshold > li->u.ulog.qthreshold)
612 qthreshold = li->u.ulog.qthreshold;
613
614
615 switch (inst->copy_mode) {
616 case NFULNL_COPY_META:
617 case NFULNL_COPY_NONE:
618 data_len = 0;
619 break;
620
621 case NFULNL_COPY_PACKET:
622 if (inst->copy_range == 0
623 || inst->copy_range > skb->len)
624 data_len = skb->len;
625 else
626 data_len = inst->copy_range;
627
628 size += nla_total_size(data_len);
629 break;
630
631 case NFULNL_COPY_DISABLED:
632 default:
633 goto unlock_and_release;
634 }
635
636 if (inst->skb &&
637 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
638 /* either the queue len is too high or we don't have
639 * enough room in the skb left. flush to userspace. */
640 __nfulnl_flush(inst);
641 }
642
643 if (!inst->skb) {
644 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
645 if (!inst->skb)
646 goto alloc_failure;
647 }
648
649 inst->qlen++;
650
651 __build_packet_message(inst, skb, data_len, pf,
652 hooknum, in, out, prefix, plen);
653
654 if (inst->qlen >= qthreshold)
655 __nfulnl_flush(inst);
656 /* timer_pending always called within inst->lock, so there
657 * is no chance of a race here */
658 else if (!timer_pending(&inst->timer)) {
659 instance_get(inst);
660 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
661 add_timer(&inst->timer);
662 }
663
664 unlock_and_release:
665 spin_unlock_bh(&inst->lock);
666 instance_put(inst);
667 return;
668
669 alloc_failure:
670 /* FIXME: statistics */
671 goto unlock_and_release;
672 }
673 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
674
675 static int
676 nfulnl_rcv_nl_event(struct notifier_block *this,
677 unsigned long event, void *ptr)
678 {
679 struct netlink_notify *n = ptr;
680
681 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
682 int i;
683
684 /* destroy all instances for this pid */
685 spin_lock_bh(&instances_lock);
686 for (i = 0; i < INSTANCE_BUCKETS; i++) {
687 struct hlist_node *tmp, *t2;
688 struct nfulnl_instance *inst;
689 struct hlist_head *head = &instance_table[i];
690
691 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
692 if ((net_eq(n->net, &init_net)) &&
693 (n->pid == inst->peer_pid))
694 __instance_destroy(inst);
695 }
696 }
697 spin_unlock_bh(&instances_lock);
698 }
699 return NOTIFY_DONE;
700 }
701
702 static struct notifier_block nfulnl_rtnl_notifier = {
703 .notifier_call = nfulnl_rcv_nl_event,
704 };
705
706 static int
707 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
708 const struct nlmsghdr *nlh,
709 const struct nlattr * const nfqa[])
710 {
711 return -ENOTSUPP;
712 }
713
714 static struct nf_logger nfulnl_logger __read_mostly = {
715 .name = "nfnetlink_log",
716 .logfn = &nfulnl_log_packet,
717 .me = THIS_MODULE,
718 };
719
720 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
721 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
722 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
723 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
724 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
725 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
726 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
727 };
728
729 static int
730 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
731 const struct nlmsghdr *nlh,
732 const struct nlattr * const nfula[])
733 {
734 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
735 u_int16_t group_num = ntohs(nfmsg->res_id);
736 struct nfulnl_instance *inst;
737 struct nfulnl_msg_config_cmd *cmd = NULL;
738 int ret = 0;
739
740 if (nfula[NFULA_CFG_CMD]) {
741 u_int8_t pf = nfmsg->nfgen_family;
742 cmd = nla_data(nfula[NFULA_CFG_CMD]);
743
744 /* Commands without queue context */
745 switch (cmd->command) {
746 case NFULNL_CFG_CMD_PF_BIND:
747 return nf_log_bind_pf(pf, &nfulnl_logger);
748 case NFULNL_CFG_CMD_PF_UNBIND:
749 nf_log_unbind_pf(pf);
750 return 0;
751 }
752 }
753
754 inst = instance_lookup_get(group_num);
755 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
756 ret = -EPERM;
757 goto out_put;
758 }
759
760 if (cmd != NULL) {
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 (IS_ERR(inst)) {
771 ret = PTR_ERR(inst);
772 goto out;
773 }
774 break;
775 case NFULNL_CFG_CMD_UNBIND:
776 if (!inst) {
777 ret = -ENODEV;
778 goto out;
779 }
780
781 instance_destroy(inst);
782 goto out_put;
783 default:
784 ret = -ENOTSUPP;
785 break;
786 }
787 }
788
789 if (nfula[NFULA_CFG_MODE]) {
790 struct nfulnl_msg_config_mode *params;
791 params = nla_data(nfula[NFULA_CFG_MODE]);
792
793 if (!inst) {
794 ret = -ENODEV;
795 goto out;
796 }
797 nfulnl_set_mode(inst, params->copy_mode,
798 ntohl(params->copy_range));
799 }
800
801 if (nfula[NFULA_CFG_TIMEOUT]) {
802 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
803
804 if (!inst) {
805 ret = -ENODEV;
806 goto out;
807 }
808 nfulnl_set_timeout(inst, ntohl(timeout));
809 }
810
811 if (nfula[NFULA_CFG_NLBUFSIZ]) {
812 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
813
814 if (!inst) {
815 ret = -ENODEV;
816 goto out;
817 }
818 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
819 }
820
821 if (nfula[NFULA_CFG_QTHRESH]) {
822 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
823
824 if (!inst) {
825 ret = -ENODEV;
826 goto out;
827 }
828 nfulnl_set_qthresh(inst, ntohl(qthresh));
829 }
830
831 if (nfula[NFULA_CFG_FLAGS]) {
832 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
833
834 if (!inst) {
835 ret = -ENODEV;
836 goto out;
837 }
838 nfulnl_set_flags(inst, ntohs(flags));
839 }
840
841 out_put:
842 instance_put(inst);
843 out:
844 return ret;
845 }
846
847 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
848 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
849 .attr_count = NFULA_MAX, },
850 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
851 .attr_count = NFULA_CFG_MAX,
852 .policy = nfula_cfg_policy },
853 };
854
855 static const struct nfnetlink_subsystem nfulnl_subsys = {
856 .name = "log",
857 .subsys_id = NFNL_SUBSYS_ULOG,
858 .cb_count = NFULNL_MSG_MAX,
859 .cb = nfulnl_cb,
860 };
861
862 #ifdef CONFIG_PROC_FS
863 struct iter_state {
864 unsigned int bucket;
865 };
866
867 static struct hlist_node *get_first(struct iter_state *st)
868 {
869 if (!st)
870 return NULL;
871
872 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
873 if (!hlist_empty(&instance_table[st->bucket]))
874 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
875 }
876 return NULL;
877 }
878
879 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
880 {
881 h = rcu_dereference_bh(hlist_next_rcu(h));
882 while (!h) {
883 if (++st->bucket >= INSTANCE_BUCKETS)
884 return NULL;
885
886 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
887 }
888 return h;
889 }
890
891 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
892 {
893 struct hlist_node *head;
894 head = get_first(st);
895
896 if (head)
897 while (pos && (head = get_next(st, head)))
898 pos--;
899 return pos ? NULL : head;
900 }
901
902 static void *seq_start(struct seq_file *seq, loff_t *pos)
903 __acquires(rcu_bh)
904 {
905 rcu_read_lock_bh();
906 return get_idx(seq->private, *pos);
907 }
908
909 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
910 {
911 (*pos)++;
912 return get_next(s->private, v);
913 }
914
915 static void seq_stop(struct seq_file *s, void *v)
916 __releases(rcu_bh)
917 {
918 rcu_read_unlock_bh();
919 }
920
921 static int seq_show(struct seq_file *s, void *v)
922 {
923 const struct nfulnl_instance *inst = v;
924
925 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
926 inst->group_num,
927 inst->peer_pid, inst->qlen,
928 inst->copy_mode, inst->copy_range,
929 inst->flushtimeout, atomic_read(&inst->use));
930 }
931
932 static const struct seq_operations nful_seq_ops = {
933 .start = seq_start,
934 .next = seq_next,
935 .stop = seq_stop,
936 .show = seq_show,
937 };
938
939 static int nful_open(struct inode *inode, struct file *file)
940 {
941 return seq_open_private(file, &nful_seq_ops,
942 sizeof(struct iter_state));
943 }
944
945 static const struct file_operations nful_file_ops = {
946 .owner = THIS_MODULE,
947 .open = nful_open,
948 .read = seq_read,
949 .llseek = seq_lseek,
950 .release = seq_release_private,
951 };
952
953 #endif /* PROC_FS */
954
955 static int __init nfnetlink_log_init(void)
956 {
957 int i, status = -ENOMEM;
958
959 for (i = 0; i < INSTANCE_BUCKETS; i++)
960 INIT_HLIST_HEAD(&instance_table[i]);
961
962 /* it's not really all that important to have a random value, so
963 * we can do this from the init function, even if there hasn't
964 * been that much entropy yet */
965 get_random_bytes(&hash_init, sizeof(hash_init));
966
967 netlink_register_notifier(&nfulnl_rtnl_notifier);
968 status = nfnetlink_subsys_register(&nfulnl_subsys);
969 if (status < 0) {
970 printk(KERN_ERR "log: failed to create netlink socket\n");
971 goto cleanup_netlink_notifier;
972 }
973
974 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
975 if (status < 0) {
976 printk(KERN_ERR "log: failed to register logger\n");
977 goto cleanup_subsys;
978 }
979
980 #ifdef CONFIG_PROC_FS
981 if (!proc_create("nfnetlink_log", 0440,
982 proc_net_netfilter, &nful_file_ops))
983 goto cleanup_logger;
984 #endif
985 return status;
986
987 #ifdef CONFIG_PROC_FS
988 cleanup_logger:
989 nf_log_unregister(&nfulnl_logger);
990 #endif
991 cleanup_subsys:
992 nfnetlink_subsys_unregister(&nfulnl_subsys);
993 cleanup_netlink_notifier:
994 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
995 return status;
996 }
997
998 static void __exit nfnetlink_log_fini(void)
999 {
1000 nf_log_unregister(&nfulnl_logger);
1001 #ifdef CONFIG_PROC_FS
1002 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1003 #endif
1004 nfnetlink_subsys_unregister(&nfulnl_subsys);
1005 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1006 }
1007
1008 MODULE_DESCRIPTION("netfilter userspace logging");
1009 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1010 MODULE_LICENSE("GPL");
1011 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1012
1013 module_init(nfnetlink_log_init);
1014 module_exit(nfnetlink_log_fini);
linux-next