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audit: allow interfield comparison in audit rules
[linux-2.6.git] / net / netfilter / nfnetlink_log.c
blob66b2c54c544f6bbf87c20500d97452122f2b2fcf
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 <linux/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 if (n > pkt_size) {
311 /* try to allocate only as much as we need for current
312 * packet */
313
314 skb = alloc_skb(pkt_size, GFP_ATOMIC);
315 if (!skb)
316 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
317 pkt_size);
318 }
319 }
320
321 return skb;
322 }
323
324 static int
325 __nfulnl_send(struct nfulnl_instance *inst)
326 {
327 int status = -1;
328
329 if (inst->qlen > 1)
330 NLMSG_PUT(inst->skb, 0, 0,
331 NLMSG_DONE,
332 sizeof(struct nfgenmsg));
333
334 status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid,
335 MSG_DONTWAIT);
336
337 inst->qlen = 0;
338 inst->skb = NULL;
339
340 nlmsg_failure:
341 return status;
342 }
343
344 static void
345 __nfulnl_flush(struct nfulnl_instance *inst)
346 {
347 /* timer holds a reference */
348 if (del_timer(&inst->timer))
349 instance_put(inst);
350 if (inst->skb)
351 __nfulnl_send(inst);
352 }
353
354 static void
355 nfulnl_timer(unsigned long data)
356 {
357 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
358
359 spin_lock_bh(&inst->lock);
360 if (inst->skb)
361 __nfulnl_send(inst);
362 spin_unlock_bh(&inst->lock);
363 instance_put(inst);
364 }
365
366 /* This is an inline function, we don't really care about a long
367 * list of arguments */
368 static inline int
369 __build_packet_message(struct nfulnl_instance *inst,
370 const struct sk_buff *skb,
371 unsigned int data_len,
372 u_int8_t pf,
373 unsigned int hooknum,
374 const struct net_device *indev,
375 const struct net_device *outdev,
376 const char *prefix, unsigned int plen)
377 {
378 struct nfulnl_msg_packet_hdr pmsg;
379 struct nlmsghdr *nlh;
380 struct nfgenmsg *nfmsg;
381 sk_buff_data_t old_tail = inst->skb->tail;
382
383 nlh = NLMSG_PUT(inst->skb, 0, 0,
384 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
385 sizeof(struct nfgenmsg));
386 nfmsg = NLMSG_DATA(nlh);
387 nfmsg->nfgen_family = pf;
388 nfmsg->version = NFNETLINK_V0;
389 nfmsg->res_id = htons(inst->group_num);
390
391 pmsg.hw_protocol = skb->protocol;
392 pmsg.hook = hooknum;
393
394 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
395
396 if (prefix)
397 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
398
399 if (indev) {
400 #ifndef CONFIG_BRIDGE_NETFILTER
401 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
402 htonl(indev->ifindex));
403 #else
404 if (pf == PF_BRIDGE) {
405 /* Case 1: outdev is physical input device, we need to
406 * look for bridge group (when called from
407 * netfilter_bridge) */
408 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
409 htonl(indev->ifindex));
410 /* this is the bridge group "brX" */
411 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
412 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
413 htonl(br_port_get_rcu(indev)->br->dev->ifindex));
414 } else {
415 /* Case 2: indev is bridge group, we need to look for
416 * physical device (when called from ipv4) */
417 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
418 htonl(indev->ifindex));
419 if (skb->nf_bridge && skb->nf_bridge->physindev)
420 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
421 htonl(skb->nf_bridge->physindev->ifindex));
422 }
423 #endif
424 }
425
426 if (outdev) {
427 #ifndef CONFIG_BRIDGE_NETFILTER
428 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
429 htonl(outdev->ifindex));
430 #else
431 if (pf == PF_BRIDGE) {
432 /* Case 1: outdev is physical output device, we need to
433 * look for bridge group (when called from
434 * netfilter_bridge) */
435 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
436 htonl(outdev->ifindex));
437 /* this is the bridge group "brX" */
438 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
439 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
440 htonl(br_port_get_rcu(outdev)->br->dev->ifindex));
441 } else {
442 /* Case 2: indev is a bridge group, we need to look
443 * for physical device (when called from ipv4) */
444 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
445 htonl(outdev->ifindex));
446 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
447 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
448 htonl(skb->nf_bridge->physoutdev->ifindex));
449 }
450 #endif
451 }
452
453 if (skb->mark)
454 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
455
456 if (indev && skb->dev &&
457 skb->mac_header != skb->network_header) {
458 struct nfulnl_msg_packet_hw phw;
459 int len = dev_parse_header(skb, phw.hw_addr);
460 if (len > 0) {
461 phw.hw_addrlen = htons(len);
462 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
463 }
464 }
465
466 if (indev && skb_mac_header_was_set(skb)) {
467 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
468 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
469 htons(skb->dev->hard_header_len));
470 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
471 skb_mac_header(skb));
472 }
473
474 if (skb->tstamp.tv64) {
475 struct nfulnl_msg_packet_timestamp ts;
476 struct timeval tv = ktime_to_timeval(skb->tstamp);
477 ts.sec = cpu_to_be64(tv.tv_sec);
478 ts.usec = cpu_to_be64(tv.tv_usec);
479
480 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
481 }
482
483 /* UID */
484 if (skb->sk) {
485 read_lock_bh(&skb->sk->sk_callback_lock);
486 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
487 struct file *file = skb->sk->sk_socket->file;
488 __be32 uid = htonl(file->f_cred->fsuid);
489 __be32 gid = htonl(file->f_cred->fsgid);
490 /* need to unlock here since NLA_PUT may goto */
491 read_unlock_bh(&skb->sk->sk_callback_lock);
492 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
493 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
494 } else
495 read_unlock_bh(&skb->sk->sk_callback_lock);
496 }
497
498 /* local sequence number */
499 if (inst->flags & NFULNL_CFG_F_SEQ)
500 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
501
502 /* global sequence number */
503 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
504 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
505 htonl(atomic_inc_return(&global_seq)));
506
507 if (data_len) {
508 struct nlattr *nla;
509 int size = nla_attr_size(data_len);
510
511 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
512 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
513 goto nlmsg_failure;
514 }
515
516 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
517 nla->nla_type = NFULA_PAYLOAD;
518 nla->nla_len = size;
519
520 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
521 BUG();
522 }
523
524 nlh->nlmsg_len = inst->skb->tail - old_tail;
525 return 0;
526
527 nlmsg_failure:
528 nla_put_failure:
529 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
530 return -1;
531 }
532
533 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
534
535 static struct nf_loginfo default_loginfo = {
536 .type = NF_LOG_TYPE_ULOG,
537 .u = {
538 .ulog = {
539 .copy_len = 0xffff,
540 .group = 0,
541 .qthreshold = 1,
542 },
543 },
544 };
545
546 /* log handler for internal netfilter logging api */
547 void
548 nfulnl_log_packet(u_int8_t pf,
549 unsigned int hooknum,
550 const struct sk_buff *skb,
551 const struct net_device *in,
552 const struct net_device *out,
553 const struct nf_loginfo *li_user,
554 const char *prefix)
555 {
556 unsigned int size, data_len;
557 struct nfulnl_instance *inst;
558 const struct nf_loginfo *li;
559 unsigned int qthreshold;
560 unsigned int plen;
561
562 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
563 li = li_user;
564 else
565 li = &default_loginfo;
566
567 inst = instance_lookup_get(li->u.ulog.group);
568 if (!inst)
569 return;
570
571 plen = 0;
572 if (prefix)
573 plen = strlen(prefix) + 1;
574
575 /* FIXME: do we want to make the size calculation conditional based on
576 * what is actually present? way more branches and checks, but more
577 * memory efficient... */
578 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
579 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
580 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
581 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
582 #ifdef CONFIG_BRIDGE_NETFILTER
583 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
584 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
585 #endif
586 + nla_total_size(sizeof(u_int32_t)) /* mark */
587 + nla_total_size(sizeof(u_int32_t)) /* uid */
588 + nla_total_size(sizeof(u_int32_t)) /* gid */
589 + nla_total_size(plen) /* prefix */
590 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
591 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
592
593 if (in && skb_mac_header_was_set(skb)) {
594 size += nla_total_size(skb->dev->hard_header_len)
595 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
596 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
597 }
598
599 spin_lock_bh(&inst->lock);
600
601 if (inst->flags & NFULNL_CFG_F_SEQ)
602 size += nla_total_size(sizeof(u_int32_t));
603 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
604 size += nla_total_size(sizeof(u_int32_t));
605
606 qthreshold = inst->qthreshold;
607 /* per-rule qthreshold overrides per-instance */
608 if (li->u.ulog.qthreshold)
609 if (qthreshold > li->u.ulog.qthreshold)
610 qthreshold = li->u.ulog.qthreshold;
611
612
613 switch (inst->copy_mode) {
614 case NFULNL_COPY_META:
615 case NFULNL_COPY_NONE:
616 data_len = 0;
617 break;
618
619 case NFULNL_COPY_PACKET:
620 if (inst->copy_range == 0
621 || inst->copy_range > skb->len)
622 data_len = skb->len;
623 else
624 data_len = inst->copy_range;
625
626 size += nla_total_size(data_len);
627 break;
628
629 case NFULNL_COPY_DISABLED:
630 default:
631 goto unlock_and_release;
632 }
633
634 if (inst->skb &&
635 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
636 /* either the queue len is too high or we don't have
637 * enough room in the skb left. flush to userspace. */
638 __nfulnl_flush(inst);
639 }
640
641 if (!inst->skb) {
642 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
643 if (!inst->skb)
644 goto alloc_failure;
645 }
646
647 inst->qlen++;
648
649 __build_packet_message(inst, skb, data_len, pf,
650 hooknum, in, out, prefix, plen);
651
652 if (inst->qlen >= qthreshold)
653 __nfulnl_flush(inst);
654 /* timer_pending always called within inst->lock, so there
655 * is no chance of a race here */
656 else if (!timer_pending(&inst->timer)) {
657 instance_get(inst);
658 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
659 add_timer(&inst->timer);
660 }
661
662 unlock_and_release:
663 spin_unlock_bh(&inst->lock);
664 instance_put(inst);
665 return;
666
667 alloc_failure:
668 /* FIXME: statistics */
669 goto unlock_and_release;
670 }
671 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
672
673 static int
674 nfulnl_rcv_nl_event(struct notifier_block *this,
675 unsigned long event, void *ptr)
676 {
677 struct netlink_notify *n = ptr;
678
679 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
680 int i;
681
682 /* destroy all instances for this pid */
683 spin_lock_bh(&instances_lock);
684 for (i = 0; i < INSTANCE_BUCKETS; i++) {
685 struct hlist_node *tmp, *t2;
686 struct nfulnl_instance *inst;
687 struct hlist_head *head = &instance_table[i];
688
689 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
690 if ((net_eq(n->net, &init_net)) &&
691 (n->pid == inst->peer_pid))
692 __instance_destroy(inst);
693 }
694 }
695 spin_unlock_bh(&instances_lock);
696 }
697 return NOTIFY_DONE;
698 }
699
700 static struct notifier_block nfulnl_rtnl_notifier = {
701 .notifier_call = nfulnl_rcv_nl_event,
702 };
703
704 static int
705 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
706 const struct nlmsghdr *nlh,
707 const struct nlattr * const nfqa[])
708 {
709 return -ENOTSUPP;
710 }
711
712 static struct nf_logger nfulnl_logger __read_mostly = {
713 .name = "nfnetlink_log",
714 .logfn = &nfulnl_log_packet,
715 .me = THIS_MODULE,
716 };
717
718 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
719 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
720 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
721 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
722 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
723 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
724 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
725 };
726
727 static int
728 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
729 const struct nlmsghdr *nlh,
730 const struct nlattr * const nfula[])
731 {
732 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
733 u_int16_t group_num = ntohs(nfmsg->res_id);
734 struct nfulnl_instance *inst;
735 struct nfulnl_msg_config_cmd *cmd = NULL;
736 int ret = 0;
737
738 if (nfula[NFULA_CFG_CMD]) {
739 u_int8_t pf = nfmsg->nfgen_family;
740 cmd = nla_data(nfula[NFULA_CFG_CMD]);
741
742 /* Commands without queue context */
743 switch (cmd->command) {
744 case NFULNL_CFG_CMD_PF_BIND:
745 return nf_log_bind_pf(pf, &nfulnl_logger);
746 case NFULNL_CFG_CMD_PF_UNBIND:
747 nf_log_unbind_pf(pf);
748 return 0;
749 }
750 }
751
752 inst = instance_lookup_get(group_num);
753 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
754 ret = -EPERM;
755 goto out_put;
756 }
757
758 if (cmd != NULL) {
759 switch (cmd->command) {
760 case NFULNL_CFG_CMD_BIND:
761 if (inst) {
762 ret = -EBUSY;
763 goto out_put;
764 }
765
766 inst = instance_create(group_num,
767 NETLINK_CB(skb).pid);
768 if (IS_ERR(inst)) {
769 ret = PTR_ERR(inst);
770 goto out;
771 }
772 break;
773 case NFULNL_CFG_CMD_UNBIND:
774 if (!inst) {
775 ret = -ENODEV;
776 goto out;
777 }
778
779 instance_destroy(inst);
780 goto out_put;
781 default:
782 ret = -ENOTSUPP;
783 break;
784 }
785 }
786
787 if (nfula[NFULA_CFG_MODE]) {
788 struct nfulnl_msg_config_mode *params;
789 params = nla_data(nfula[NFULA_CFG_MODE]);
790
791 if (!inst) {
792 ret = -ENODEV;
793 goto out;
794 }
795 nfulnl_set_mode(inst, params->copy_mode,
796 ntohl(params->copy_range));
797 }
798
799 if (nfula[NFULA_CFG_TIMEOUT]) {
800 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
801
802 if (!inst) {
803 ret = -ENODEV;
804 goto out;
805 }
806 nfulnl_set_timeout(inst, ntohl(timeout));
807 }
808
809 if (nfula[NFULA_CFG_NLBUFSIZ]) {
810 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
811
812 if (!inst) {
813 ret = -ENODEV;
814 goto out;
815 }
816 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
817 }
818
819 if (nfula[NFULA_CFG_QTHRESH]) {
820 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
821
822 if (!inst) {
823 ret = -ENODEV;
824 goto out;
825 }
826 nfulnl_set_qthresh(inst, ntohl(qthresh));
827 }
828
829 if (nfula[NFULA_CFG_FLAGS]) {
830 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
831
832 if (!inst) {
833 ret = -ENODEV;
834 goto out;
835 }
836 nfulnl_set_flags(inst, ntohs(flags));
837 }
838
839 out_put:
840 instance_put(inst);
841 out:
842 return ret;
843 }
844
845 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
846 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
847 .attr_count = NFULA_MAX, },
848 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
849 .attr_count = NFULA_CFG_MAX,
850 .policy = nfula_cfg_policy },
851 };
852
853 static const struct nfnetlink_subsystem nfulnl_subsys = {
854 .name = "log",
855 .subsys_id = NFNL_SUBSYS_ULOG,
856 .cb_count = NFULNL_MSG_MAX,
857 .cb = nfulnl_cb,
858 };
859
860 #ifdef CONFIG_PROC_FS
861 struct iter_state {
862 unsigned int bucket;
863 };
864
865 static struct hlist_node *get_first(struct iter_state *st)
866 {
867 if (!st)
868 return NULL;
869
870 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
871 if (!hlist_empty(&instance_table[st->bucket]))
872 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
873 }
874 return NULL;
875 }
876
877 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
878 {
879 h = rcu_dereference_bh(hlist_next_rcu(h));
880 while (!h) {
881 if (++st->bucket >= INSTANCE_BUCKETS)
882 return NULL;
883
884 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
885 }
886 return h;
887 }
888
889 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
890 {
891 struct hlist_node *head;
892 head = get_first(st);
893
894 if (head)
895 while (pos && (head = get_next(st, head)))
896 pos--;
897 return pos ? NULL : head;
898 }
899
900 static void *seq_start(struct seq_file *seq, loff_t *pos)
901 __acquires(rcu_bh)
902 {
903 rcu_read_lock_bh();
904 return get_idx(seq->private, *pos);
905 }
906
907 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
908 {
909 (*pos)++;
910 return get_next(s->private, v);
911 }
912
913 static void seq_stop(struct seq_file *s, void *v)
914 __releases(rcu_bh)
915 {
916 rcu_read_unlock_bh();
917 }
918
919 static int seq_show(struct seq_file *s, void *v)
920 {
921 const struct nfulnl_instance *inst = v;
922
923 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
924 inst->group_num,
925 inst->peer_pid, inst->qlen,
926 inst->copy_mode, inst->copy_range,
927 inst->flushtimeout, atomic_read(&inst->use));
928 }
929
930 static const struct seq_operations nful_seq_ops = {
931 .start = seq_start,
932 .next = seq_next,
933 .stop = seq_stop,
934 .show = seq_show,
935 };
936
937 static int nful_open(struct inode *inode, struct file *file)
938 {
939 return seq_open_private(file, &nful_seq_ops,
940 sizeof(struct iter_state));
941 }
942
943 static const struct file_operations nful_file_ops = {
944 .owner = THIS_MODULE,
945 .open = nful_open,
946 .read = seq_read,
947 .llseek = seq_lseek,
948 .release = seq_release_private,
949 };
950
951 #endif /* PROC_FS */
952
953 static int __init nfnetlink_log_init(void)
954 {
955 int i, status = -ENOMEM;
956
957 for (i = 0; i < INSTANCE_BUCKETS; i++)
958 INIT_HLIST_HEAD(&instance_table[i]);
959
960 /* it's not really all that important to have a random value, so
961 * we can do this from the init function, even if there hasn't
962 * been that much entropy yet */
963 get_random_bytes(&hash_init, sizeof(hash_init));
964
965 netlink_register_notifier(&nfulnl_rtnl_notifier);
966 status = nfnetlink_subsys_register(&nfulnl_subsys);
967 if (status < 0) {
968 printk(KERN_ERR "log: failed to create netlink socket\n");
969 goto cleanup_netlink_notifier;
970 }
971
972 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
973 if (status < 0) {
974 printk(KERN_ERR "log: failed to register logger\n");
975 goto cleanup_subsys;
976 }
977
978 #ifdef CONFIG_PROC_FS
979 if (!proc_create("nfnetlink_log", 0440,
980 proc_net_netfilter, &nful_file_ops))
981 goto cleanup_logger;
982 #endif
983 return status;
984
985 #ifdef CONFIG_PROC_FS
986 cleanup_logger:
987 nf_log_unregister(&nfulnl_logger);
988 #endif
989 cleanup_subsys:
990 nfnetlink_subsys_unregister(&nfulnl_subsys);
991 cleanup_netlink_notifier:
992 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
993 return status;
994 }
995
996 static void __exit nfnetlink_log_fini(void)
997 {
998 nf_log_unregister(&nfulnl_logger);
999 #ifdef CONFIG_PROC_FS
1000 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1001 #endif
1002 nfnetlink_subsys_unregister(&nfulnl_subsys);
1003 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1004 }
1005
1006 MODULE_DESCRIPTION("netfilter userspace logging");
1007 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1008 MODULE_LICENSE("GPL");
1009 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1010
1011 module_init(nfnetlink_log_init);
1012 module_exit(nfnetlink_log_fini);
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