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Merge branch 'oprofile/core' (early part) into oprofile/perf
[linux-2.6/x86.git] / net / netfilter / nfnetlink_log.c
blob6a1572b0ab416a65425abc135cca9d93a4769911
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 struct nf_loginfo *li,
380 const char *prefix, unsigned int plen)
381 {
382 struct nfulnl_msg_packet_hdr pmsg;
383 struct nlmsghdr *nlh;
384 struct nfgenmsg *nfmsg;
385 __be32 tmp_uint;
386 sk_buff_data_t old_tail = inst->skb->tail;
387
388 nlh = NLMSG_PUT(inst->skb, 0, 0,
389 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
390 sizeof(struct nfgenmsg));
391 nfmsg = NLMSG_DATA(nlh);
392 nfmsg->nfgen_family = pf;
393 nfmsg->version = NFNETLINK_V0;
394 nfmsg->res_id = htons(inst->group_num);
395
396 pmsg.hw_protocol = skb->protocol;
397 pmsg.hook = hooknum;
398
399 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
400
401 if (prefix)
402 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
403
404 if (indev) {
405 #ifndef CONFIG_BRIDGE_NETFILTER
406 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
407 htonl(indev->ifindex));
408 #else
409 if (pf == PF_BRIDGE) {
410 /* Case 1: outdev is physical input device, we need to
411 * look for bridge group (when called from
412 * netfilter_bridge) */
413 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
414 htonl(indev->ifindex));
415 /* this is the bridge group "brX" */
416 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
417 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
418 htonl(br_port_get_rcu(indev)->br->dev->ifindex));
419 } else {
420 /* Case 2: indev is bridge group, we need to look for
421 * physical device (when called from ipv4) */
422 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
423 htonl(indev->ifindex));
424 if (skb->nf_bridge && skb->nf_bridge->physindev)
425 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
426 htonl(skb->nf_bridge->physindev->ifindex));
427 }
428 #endif
429 }
430
431 if (outdev) {
432 tmp_uint = htonl(outdev->ifindex);
433 #ifndef CONFIG_BRIDGE_NETFILTER
434 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
435 htonl(outdev->ifindex));
436 #else
437 if (pf == PF_BRIDGE) {
438 /* Case 1: outdev is physical output device, we need to
439 * look for bridge group (when called from
440 * netfilter_bridge) */
441 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
442 htonl(outdev->ifindex));
443 /* this is the bridge group "brX" */
444 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
445 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
446 htonl(br_port_get_rcu(outdev)->br->dev->ifindex));
447 } else {
448 /* Case 2: indev is a bridge group, we need to look
449 * for physical device (when called from ipv4) */
450 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
451 htonl(outdev->ifindex));
452 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
453 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
454 htonl(skb->nf_bridge->physoutdev->ifindex));
455 }
456 #endif
457 }
458
459 if (skb->mark)
460 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
461
462 if (indev && skb->dev) {
463 struct nfulnl_msg_packet_hw phw;
464 int len = dev_parse_header(skb, phw.hw_addr);
465 if (len > 0) {
466 phw.hw_addrlen = htons(len);
467 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
468 }
469 }
470
471 if (indev && skb_mac_header_was_set(skb)) {
472 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
473 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
474 htons(skb->dev->hard_header_len));
475 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
476 skb_mac_header(skb));
477 }
478
479 if (skb->tstamp.tv64) {
480 struct nfulnl_msg_packet_timestamp ts;
481 struct timeval tv = ktime_to_timeval(skb->tstamp);
482 ts.sec = cpu_to_be64(tv.tv_sec);
483 ts.usec = cpu_to_be64(tv.tv_usec);
484
485 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
486 }
487
488 /* UID */
489 if (skb->sk) {
490 read_lock_bh(&skb->sk->sk_callback_lock);
491 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
492 struct file *file = skb->sk->sk_socket->file;
493 __be32 uid = htonl(file->f_cred->fsuid);
494 __be32 gid = htonl(file->f_cred->fsgid);
495 /* need to unlock here since NLA_PUT may goto */
496 read_unlock_bh(&skb->sk->sk_callback_lock);
497 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
498 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
499 } else
500 read_unlock_bh(&skb->sk->sk_callback_lock);
501 }
502
503 /* local sequence number */
504 if (inst->flags & NFULNL_CFG_F_SEQ)
505 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
506
507 /* global sequence number */
508 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
509 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
510 htonl(atomic_inc_return(&global_seq)));
511
512 if (data_len) {
513 struct nlattr *nla;
514 int size = nla_attr_size(data_len);
515
516 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
517 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
518 goto nlmsg_failure;
519 }
520
521 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
522 nla->nla_type = NFULA_PAYLOAD;
523 nla->nla_len = size;
524
525 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
526 BUG();
527 }
528
529 nlh->nlmsg_len = inst->skb->tail - old_tail;
530 return 0;
531
532 nlmsg_failure:
533 nla_put_failure:
534 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
535 return -1;
536 }
537
538 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
539
540 static struct nf_loginfo default_loginfo = {
541 .type = NF_LOG_TYPE_ULOG,
542 .u = {
543 .ulog = {
544 .copy_len = 0xffff,
545 .group = 0,
546 .qthreshold = 1,
547 },
548 },
549 };
550
551 /* log handler for internal netfilter logging api */
552 void
553 nfulnl_log_packet(u_int8_t pf,
554 unsigned int hooknum,
555 const struct sk_buff *skb,
556 const struct net_device *in,
557 const struct net_device *out,
558 const struct nf_loginfo *li_user,
559 const char *prefix)
560 {
561 unsigned int size, data_len;
562 struct nfulnl_instance *inst;
563 const struct nf_loginfo *li;
564 unsigned int qthreshold;
565 unsigned int plen;
566
567 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
568 li = li_user;
569 else
570 li = &default_loginfo;
571
572 inst = instance_lookup_get(li->u.ulog.group);
573 if (!inst)
574 return;
575
576 plen = 0;
577 if (prefix)
578 plen = strlen(prefix) + 1;
579
580 /* FIXME: do we want to make the size calculation conditional based on
581 * what is actually present? way more branches and checks, but more
582 * memory efficient... */
583 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
584 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
585 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
586 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
587 #ifdef CONFIG_BRIDGE_NETFILTER
588 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
589 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
590 #endif
591 + nla_total_size(sizeof(u_int32_t)) /* mark */
592 + nla_total_size(sizeof(u_int32_t)) /* uid */
593 + nla_total_size(sizeof(u_int32_t)) /* gid */
594 + nla_total_size(plen) /* prefix */
595 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
596 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
597
598 if (in && skb_mac_header_was_set(skb)) {
599 size += nla_total_size(skb->dev->hard_header_len)
600 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
601 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
602 }
603
604 spin_lock_bh(&inst->lock);
605
606 if (inst->flags & NFULNL_CFG_F_SEQ)
607 size += nla_total_size(sizeof(u_int32_t));
608 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
609 size += nla_total_size(sizeof(u_int32_t));
610
611 qthreshold = inst->qthreshold;
612 /* per-rule qthreshold overrides per-instance */
613 if (li->u.ulog.qthreshold)
614 if (qthreshold > li->u.ulog.qthreshold)
615 qthreshold = li->u.ulog.qthreshold;
616
617
618 switch (inst->copy_mode) {
619 case NFULNL_COPY_META:
620 case NFULNL_COPY_NONE:
621 data_len = 0;
622 break;
623
624 case NFULNL_COPY_PACKET:
625 if (inst->copy_range == 0
626 || inst->copy_range > skb->len)
627 data_len = skb->len;
628 else
629 data_len = inst->copy_range;
630
631 size += nla_total_size(data_len);
632 break;
633
634 case NFULNL_COPY_DISABLED:
635 default:
636 goto unlock_and_release;
637 }
638
639 if (inst->skb &&
640 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
641 /* either the queue len is too high or we don't have
642 * enough room in the skb left. flush to userspace. */
643 __nfulnl_flush(inst);
644 }
645
646 if (!inst->skb) {
647 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
648 if (!inst->skb)
649 goto alloc_failure;
650 }
651
652 inst->qlen++;
653
654 __build_packet_message(inst, skb, data_len, pf,
655 hooknum, in, out, li, prefix, plen);
656
657 if (inst->qlen >= qthreshold)
658 __nfulnl_flush(inst);
659 /* timer_pending always called within inst->lock, so there
660 * is no chance of a race here */
661 else if (!timer_pending(&inst->timer)) {
662 instance_get(inst);
663 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
664 add_timer(&inst->timer);
665 }
666
667 unlock_and_release:
668 spin_unlock_bh(&inst->lock);
669 instance_put(inst);
670 return;
671
672 alloc_failure:
673 /* FIXME: statistics */
674 goto unlock_and_release;
675 }
676 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
677
678 static int
679 nfulnl_rcv_nl_event(struct notifier_block *this,
680 unsigned long event, void *ptr)
681 {
682 struct netlink_notify *n = ptr;
683
684 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
685 int i;
686
687 /* destroy all instances for this pid */
688 spin_lock_bh(&instances_lock);
689 for (i = 0; i < INSTANCE_BUCKETS; i++) {
690 struct hlist_node *tmp, *t2;
691 struct nfulnl_instance *inst;
692 struct hlist_head *head = &instance_table[i];
693
694 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
695 if ((net_eq(n->net, &init_net)) &&
696 (n->pid == inst->peer_pid))
697 __instance_destroy(inst);
698 }
699 }
700 spin_unlock_bh(&instances_lock);
701 }
702 return NOTIFY_DONE;
703 }
704
705 static struct notifier_block nfulnl_rtnl_notifier = {
706 .notifier_call = nfulnl_rcv_nl_event,
707 };
708
709 static int
710 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
711 const struct nlmsghdr *nlh,
712 const struct nlattr * const nfqa[])
713 {
714 return -ENOTSUPP;
715 }
716
717 static struct nf_logger nfulnl_logger __read_mostly = {
718 .name = "nfnetlink_log",
719 .logfn = &nfulnl_log_packet,
720 .me = THIS_MODULE,
721 };
722
723 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
724 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
725 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
726 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
727 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
728 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
729 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
730 };
731
732 static int
733 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
734 const struct nlmsghdr *nlh,
735 const struct nlattr * const nfula[])
736 {
737 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
738 u_int16_t group_num = ntohs(nfmsg->res_id);
739 struct nfulnl_instance *inst;
740 struct nfulnl_msg_config_cmd *cmd = NULL;
741 int ret = 0;
742
743 if (nfula[NFULA_CFG_CMD]) {
744 u_int8_t pf = nfmsg->nfgen_family;
745 cmd = nla_data(nfula[NFULA_CFG_CMD]);
746
747 /* Commands without queue context */
748 switch (cmd->command) {
749 case NFULNL_CFG_CMD_PF_BIND:
750 return nf_log_bind_pf(pf, &nfulnl_logger);
751 case NFULNL_CFG_CMD_PF_UNBIND:
752 nf_log_unbind_pf(pf);
753 return 0;
754 }
755 }
756
757 inst = instance_lookup_get(group_num);
758 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
759 ret = -EPERM;
760 goto out_put;
761 }
762
763 if (cmd != NULL) {
764 switch (cmd->command) {
765 case NFULNL_CFG_CMD_BIND:
766 if (inst) {
767 ret = -EBUSY;
768 goto out_put;
769 }
770
771 inst = instance_create(group_num,
772 NETLINK_CB(skb).pid);
773 if (IS_ERR(inst)) {
774 ret = PTR_ERR(inst);
775 goto out;
776 }
777 break;
778 case NFULNL_CFG_CMD_UNBIND:
779 if (!inst) {
780 ret = -ENODEV;
781 goto out;
782 }
783
784 instance_destroy(inst);
785 goto out_put;
786 default:
787 ret = -ENOTSUPP;
788 break;
789 }
790 }
791
792 if (nfula[NFULA_CFG_MODE]) {
793 struct nfulnl_msg_config_mode *params;
794 params = nla_data(nfula[NFULA_CFG_MODE]);
795
796 if (!inst) {
797 ret = -ENODEV;
798 goto out;
799 }
800 nfulnl_set_mode(inst, params->copy_mode,
801 ntohl(params->copy_range));
802 }
803
804 if (nfula[NFULA_CFG_TIMEOUT]) {
805 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
806
807 if (!inst) {
808 ret = -ENODEV;
809 goto out;
810 }
811 nfulnl_set_timeout(inst, ntohl(timeout));
812 }
813
814 if (nfula[NFULA_CFG_NLBUFSIZ]) {
815 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
816
817 if (!inst) {
818 ret = -ENODEV;
819 goto out;
820 }
821 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
822 }
823
824 if (nfula[NFULA_CFG_QTHRESH]) {
825 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
826
827 if (!inst) {
828 ret = -ENODEV;
829 goto out;
830 }
831 nfulnl_set_qthresh(inst, ntohl(qthresh));
832 }
833
834 if (nfula[NFULA_CFG_FLAGS]) {
835 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
836
837 if (!inst) {
838 ret = -ENODEV;
839 goto out;
840 }
841 nfulnl_set_flags(inst, ntohs(flags));
842 }
843
844 out_put:
845 instance_put(inst);
846 out:
847 return ret;
848 }
849
850 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
851 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
852 .attr_count = NFULA_MAX, },
853 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
854 .attr_count = NFULA_CFG_MAX,
855 .policy = nfula_cfg_policy },
856 };
857
858 static const struct nfnetlink_subsystem nfulnl_subsys = {
859 .name = "log",
860 .subsys_id = NFNL_SUBSYS_ULOG,
861 .cb_count = NFULNL_MSG_MAX,
862 .cb = nfulnl_cb,
863 };
864
865 #ifdef CONFIG_PROC_FS
866 struct iter_state {
867 unsigned int bucket;
868 };
869
870 static struct hlist_node *get_first(struct iter_state *st)
871 {
872 if (!st)
873 return NULL;
874
875 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
876 if (!hlist_empty(&instance_table[st->bucket]))
877 return rcu_dereference_bh(instance_table[st->bucket].first);
878 }
879 return NULL;
880 }
881
882 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
883 {
884 h = rcu_dereference_bh(h->next);
885 while (!h) {
886 if (++st->bucket >= INSTANCE_BUCKETS)
887 return NULL;
888
889 h = rcu_dereference_bh(instance_table[st->bucket].first);
890 }
891 return h;
892 }
893
894 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
895 {
896 struct hlist_node *head;
897 head = get_first(st);
898
899 if (head)
900 while (pos && (head = get_next(st, head)))
901 pos--;
902 return pos ? NULL : head;
903 }
904
905 static void *seq_start(struct seq_file *seq, loff_t *pos)
906 __acquires(rcu_bh)
907 {
908 rcu_read_lock_bh();
909 return get_idx(seq->private, *pos);
910 }
911
912 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
913 {
914 (*pos)++;
915 return get_next(s->private, v);
916 }
917
918 static void seq_stop(struct seq_file *s, void *v)
919 __releases(rcu_bh)
920 {
921 rcu_read_unlock_bh();
922 }
923
924 static int seq_show(struct seq_file *s, void *v)
925 {
926 const struct nfulnl_instance *inst = v;
927
928 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
929 inst->group_num,
930 inst->peer_pid, inst->qlen,
931 inst->copy_mode, inst->copy_range,
932 inst->flushtimeout, atomic_read(&inst->use));
933 }
934
935 static const struct seq_operations nful_seq_ops = {
936 .start = seq_start,
937 .next = seq_next,
938 .stop = seq_stop,
939 .show = seq_show,
940 };
941
942 static int nful_open(struct inode *inode, struct file *file)
943 {
944 return seq_open_private(file, &nful_seq_ops,
945 sizeof(struct iter_state));
946 }
947
948 static const struct file_operations nful_file_ops = {
949 .owner = THIS_MODULE,
950 .open = nful_open,
951 .read = seq_read,
952 .llseek = seq_lseek,
953 .release = seq_release_private,
954 };
955
956 #endif /* PROC_FS */
957
958 static int __init nfnetlink_log_init(void)
959 {
960 int i, status = -ENOMEM;
961
962 for (i = 0; i < INSTANCE_BUCKETS; i++)
963 INIT_HLIST_HEAD(&instance_table[i]);
964
965 /* it's not really all that important to have a random value, so
966 * we can do this from the init function, even if there hasn't
967 * been that much entropy yet */
968 get_random_bytes(&hash_init, sizeof(hash_init));
969
970 netlink_register_notifier(&nfulnl_rtnl_notifier);
971 status = nfnetlink_subsys_register(&nfulnl_subsys);
972 if (status < 0) {
973 printk(KERN_ERR "log: failed to create netlink socket\n");
974 goto cleanup_netlink_notifier;
975 }
976
977 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
978 if (status < 0) {
979 printk(KERN_ERR "log: failed to register logger\n");
980 goto cleanup_subsys;
981 }
982
983 #ifdef CONFIG_PROC_FS
984 if (!proc_create("nfnetlink_log", 0440,
985 proc_net_netfilter, &nful_file_ops))
986 goto cleanup_logger;
987 #endif
988 return status;
989
990 #ifdef CONFIG_PROC_FS
991 cleanup_logger:
992 nf_log_unregister(&nfulnl_logger);
993 #endif
994 cleanup_subsys:
995 nfnetlink_subsys_unregister(&nfulnl_subsys);
996 cleanup_netlink_notifier:
997 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
998 return status;
999 }
1000
1001 static void __exit nfnetlink_log_fini(void)
1002 {
1003 nf_log_unregister(&nfulnl_logger);
1004 #ifdef CONFIG_PROC_FS
1005 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1006 #endif
1007 nfnetlink_subsys_unregister(&nfulnl_subsys);
1008 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1009 }
1010
1011 MODULE_DESCRIPTION("netfilter userspace logging");
1012 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1013 MODULE_LICENSE("GPL");
1014 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1015
1016 module_init(nfnetlink_log_init);
1017 module_exit(nfnetlink_log_fini);
x86 "subsystem" repository