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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[deliverable/linux.git] / net / netfilter / nfnetlink_log.c
1 /*
2 * This is a module which is used for logging packets to userspace via
3 * nfetlink.
4 *
5 * (C) 2005 by Harald Welte <laforge@netfilter.org>
6 *
7 * Based on the old ipv4-only ipt_ULOG.c:
8 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/init.h>
17 #include <linux/ip.h>
18 #include <linux/ipv6.h>
19 #include <linux/netdevice.h>
20 #include <linux/netfilter.h>
21 #include <linux/netlink.h>
22 #include <linux/netfilter/nfnetlink.h>
23 #include <linux/netfilter/nfnetlink_log.h>
24 #include <linux/spinlock.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/list.h>
29 #include <linux/jhash.h>
30 #include <linux/random.h>
31 #include <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 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
395 goto nla_put_failure;
396
397 if (prefix &&
398 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
399 goto nla_put_failure;
400
401 if (indev) {
402 #ifndef CONFIG_BRIDGE_NETFILTER
403 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
404 htonl(indev->ifindex)))
405 goto nla_put_failure;
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 if (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 goto nla_put_failure;
418 } else {
419 /* Case 2: indev is bridge group, we need to look for
420 * physical device (when called from ipv4) */
421 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
422 htonl(indev->ifindex)))
423 goto nla_put_failure;
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 goto nla_put_failure;
428 }
429 #endif
430 }
431
432 if (outdev) {
433 #ifndef CONFIG_BRIDGE_NETFILTER
434 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
435 htonl(outdev->ifindex)))
436 goto nla_put_failure;
437 #else
438 if (pf == PF_BRIDGE) {
439 /* Case 1: outdev is physical output device, we need to
440 * look for bridge group (when called from
441 * netfilter_bridge) */
442 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
443 htonl(outdev->ifindex)) ||
444 /* this is the bridge group "brX" */
445 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
446 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
447 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
448 goto nla_put_failure;
449 } else {
450 /* Case 2: indev is a bridge group, we need to look
451 * for physical device (when called from ipv4) */
452 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
453 htonl(outdev->ifindex)))
454 goto nla_put_failure;
455 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
456 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
457 htonl(skb->nf_bridge->physoutdev->ifindex)))
458 goto nla_put_failure;
459 }
460 #endif
461 }
462
463 if (skb->mark &&
464 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
465 goto nla_put_failure;
466
467 if (indev && skb->dev &&
468 skb->mac_header != skb->network_header) {
469 struct nfulnl_msg_packet_hw phw;
470 int len = dev_parse_header(skb, phw.hw_addr);
471 if (len > 0) {
472 phw.hw_addrlen = htons(len);
473 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
474 goto nla_put_failure;
475 }
476 }
477
478 if (indev && skb_mac_header_was_set(skb)) {
479 if (nla_put_be32(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
480 nla_put_be16(inst->skb, NFULA_HWLEN,
481 htons(skb->dev->hard_header_len)) ||
482 nla_put(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
483 skb_mac_header(skb)))
484 goto nla_put_failure;
485 }
486
487 if (skb->tstamp.tv64) {
488 struct nfulnl_msg_packet_timestamp ts;
489 struct timeval tv = ktime_to_timeval(skb->tstamp);
490 ts.sec = cpu_to_be64(tv.tv_sec);
491 ts.usec = cpu_to_be64(tv.tv_usec);
492
493 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
494 goto nla_put_failure;
495 }
496
497 /* UID */
498 if (skb->sk) {
499 read_lock_bh(&skb->sk->sk_callback_lock);
500 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
501 struct file *file = skb->sk->sk_socket->file;
502 __be32 uid = htonl(file->f_cred->fsuid);
503 __be32 gid = htonl(file->f_cred->fsgid);
504 read_unlock_bh(&skb->sk->sk_callback_lock);
505 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
506 nla_put_be32(inst->skb, NFULA_GID, gid))
507 goto nla_put_failure;
508 } else
509 read_unlock_bh(&skb->sk->sk_callback_lock);
510 }
511
512 /* local sequence number */
513 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
514 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
515 goto nla_put_failure;
516
517 /* global sequence number */
518 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
519 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
520 htonl(atomic_inc_return(&global_seq))))
521 goto nla_put_failure;
522
523 if (data_len) {
524 struct nlattr *nla;
525 int size = nla_attr_size(data_len);
526
527 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
528 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
529 goto nlmsg_failure;
530 }
531
532 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
533 nla->nla_type = NFULA_PAYLOAD;
534 nla->nla_len = size;
535
536 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
537 BUG();
538 }
539
540 nlh->nlmsg_len = inst->skb->tail - old_tail;
541 return 0;
542
543 nlmsg_failure:
544 nla_put_failure:
545 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
546 return -1;
547 }
548
549 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
550
551 static struct nf_loginfo default_loginfo = {
552 .type = NF_LOG_TYPE_ULOG,
553 .u = {
554 .ulog = {
555 .copy_len = 0xffff,
556 .group = 0,
557 .qthreshold = 1,
558 },
559 },
560 };
561
562 /* log handler for internal netfilter logging api */
563 void
564 nfulnl_log_packet(u_int8_t pf,
565 unsigned int hooknum,
566 const struct sk_buff *skb,
567 const struct net_device *in,
568 const struct net_device *out,
569 const struct nf_loginfo *li_user,
570 const char *prefix)
571 {
572 unsigned int size, data_len;
573 struct nfulnl_instance *inst;
574 const struct nf_loginfo *li;
575 unsigned int qthreshold;
576 unsigned int plen;
577
578 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
579 li = li_user;
580 else
581 li = &default_loginfo;
582
583 inst = instance_lookup_get(li->u.ulog.group);
584 if (!inst)
585 return;
586
587 plen = 0;
588 if (prefix)
589 plen = strlen(prefix) + 1;
590
591 /* FIXME: do we want to make the size calculation conditional based on
592 * what is actually present? way more branches and checks, but more
593 * memory efficient... */
594 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
595 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
596 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
597 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
598 #ifdef CONFIG_BRIDGE_NETFILTER
599 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
600 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
601 #endif
602 + nla_total_size(sizeof(u_int32_t)) /* mark */
603 + nla_total_size(sizeof(u_int32_t)) /* uid */
604 + nla_total_size(sizeof(u_int32_t)) /* gid */
605 + nla_total_size(plen) /* prefix */
606 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
607 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
608
609 if (in && skb_mac_header_was_set(skb)) {
610 size += nla_total_size(skb->dev->hard_header_len)
611 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
612 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
613 }
614
615 spin_lock_bh(&inst->lock);
616
617 if (inst->flags & NFULNL_CFG_F_SEQ)
618 size += nla_total_size(sizeof(u_int32_t));
619 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
620 size += nla_total_size(sizeof(u_int32_t));
621
622 qthreshold = inst->qthreshold;
623 /* per-rule qthreshold overrides per-instance */
624 if (li->u.ulog.qthreshold)
625 if (qthreshold > li->u.ulog.qthreshold)
626 qthreshold = li->u.ulog.qthreshold;
627
628
629 switch (inst->copy_mode) {
630 case NFULNL_COPY_META:
631 case NFULNL_COPY_NONE:
632 data_len = 0;
633 break;
634
635 case NFULNL_COPY_PACKET:
636 if (inst->copy_range == 0
637 || inst->copy_range > skb->len)
638 data_len = skb->len;
639 else
640 data_len = inst->copy_range;
641
642 size += nla_total_size(data_len);
643 break;
644
645 case NFULNL_COPY_DISABLED:
646 default:
647 goto unlock_and_release;
648 }
649
650 if (inst->skb &&
651 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
652 /* either the queue len is too high or we don't have
653 * enough room in the skb left. flush to userspace. */
654 __nfulnl_flush(inst);
655 }
656
657 if (!inst->skb) {
658 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
659 if (!inst->skb)
660 goto alloc_failure;
661 }
662
663 inst->qlen++;
664
665 __build_packet_message(inst, skb, data_len, pf,
666 hooknum, in, out, prefix, plen);
667
668 if (inst->qlen >= qthreshold)
669 __nfulnl_flush(inst);
670 /* timer_pending always called within inst->lock, so there
671 * is no chance of a race here */
672 else if (!timer_pending(&inst->timer)) {
673 instance_get(inst);
674 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
675 add_timer(&inst->timer);
676 }
677
678 unlock_and_release:
679 spin_unlock_bh(&inst->lock);
680 instance_put(inst);
681 return;
682
683 alloc_failure:
684 /* FIXME: statistics */
685 goto unlock_and_release;
686 }
687 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
688
689 static int
690 nfulnl_rcv_nl_event(struct notifier_block *this,
691 unsigned long event, void *ptr)
692 {
693 struct netlink_notify *n = ptr;
694
695 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
696 int i;
697
698 /* destroy all instances for this pid */
699 spin_lock_bh(&instances_lock);
700 for (i = 0; i < INSTANCE_BUCKETS; i++) {
701 struct hlist_node *tmp, *t2;
702 struct nfulnl_instance *inst;
703 struct hlist_head *head = &instance_table[i];
704
705 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
706 if ((net_eq(n->net, &init_net)) &&
707 (n->pid == inst->peer_pid))
708 __instance_destroy(inst);
709 }
710 }
711 spin_unlock_bh(&instances_lock);
712 }
713 return NOTIFY_DONE;
714 }
715
716 static struct notifier_block nfulnl_rtnl_notifier = {
717 .notifier_call = nfulnl_rcv_nl_event,
718 };
719
720 static int
721 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
722 const struct nlmsghdr *nlh,
723 const struct nlattr * const nfqa[])
724 {
725 return -ENOTSUPP;
726 }
727
728 static struct nf_logger nfulnl_logger __read_mostly = {
729 .name = "nfnetlink_log",
730 .logfn = &nfulnl_log_packet,
731 .me = THIS_MODULE,
732 };
733
734 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
735 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
736 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
737 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
738 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
739 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
740 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
741 };
742
743 static int
744 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
745 const struct nlmsghdr *nlh,
746 const struct nlattr * const nfula[])
747 {
748 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
749 u_int16_t group_num = ntohs(nfmsg->res_id);
750 struct nfulnl_instance *inst;
751 struct nfulnl_msg_config_cmd *cmd = NULL;
752 int ret = 0;
753
754 if (nfula[NFULA_CFG_CMD]) {
755 u_int8_t pf = nfmsg->nfgen_family;
756 cmd = nla_data(nfula[NFULA_CFG_CMD]);
757
758 /* Commands without queue context */
759 switch (cmd->command) {
760 case NFULNL_CFG_CMD_PF_BIND:
761 return nf_log_bind_pf(pf, &nfulnl_logger);
762 case NFULNL_CFG_CMD_PF_UNBIND:
763 nf_log_unbind_pf(pf);
764 return 0;
765 }
766 }
767
768 inst = instance_lookup_get(group_num);
769 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
770 ret = -EPERM;
771 goto out_put;
772 }
773
774 if (cmd != NULL) {
775 switch (cmd->command) {
776 case NFULNL_CFG_CMD_BIND:
777 if (inst) {
778 ret = -EBUSY;
779 goto out_put;
780 }
781
782 inst = instance_create(group_num,
783 NETLINK_CB(skb).pid);
784 if (IS_ERR(inst)) {
785 ret = PTR_ERR(inst);
786 goto out;
787 }
788 break;
789 case NFULNL_CFG_CMD_UNBIND:
790 if (!inst) {
791 ret = -ENODEV;
792 goto out;
793 }
794
795 instance_destroy(inst);
796 goto out_put;
797 default:
798 ret = -ENOTSUPP;
799 break;
800 }
801 }
802
803 if (nfula[NFULA_CFG_MODE]) {
804 struct nfulnl_msg_config_mode *params;
805 params = nla_data(nfula[NFULA_CFG_MODE]);
806
807 if (!inst) {
808 ret = -ENODEV;
809 goto out;
810 }
811 nfulnl_set_mode(inst, params->copy_mode,
812 ntohl(params->copy_range));
813 }
814
815 if (nfula[NFULA_CFG_TIMEOUT]) {
816 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
817
818 if (!inst) {
819 ret = -ENODEV;
820 goto out;
821 }
822 nfulnl_set_timeout(inst, ntohl(timeout));
823 }
824
825 if (nfula[NFULA_CFG_NLBUFSIZ]) {
826 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
827
828 if (!inst) {
829 ret = -ENODEV;
830 goto out;
831 }
832 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
833 }
834
835 if (nfula[NFULA_CFG_QTHRESH]) {
836 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
837
838 if (!inst) {
839 ret = -ENODEV;
840 goto out;
841 }
842 nfulnl_set_qthresh(inst, ntohl(qthresh));
843 }
844
845 if (nfula[NFULA_CFG_FLAGS]) {
846 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
847
848 if (!inst) {
849 ret = -ENODEV;
850 goto out;
851 }
852 nfulnl_set_flags(inst, ntohs(flags));
853 }
854
855 out_put:
856 instance_put(inst);
857 out:
858 return ret;
859 }
860
861 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
862 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
863 .attr_count = NFULA_MAX, },
864 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
865 .attr_count = NFULA_CFG_MAX,
866 .policy = nfula_cfg_policy },
867 };
868
869 static const struct nfnetlink_subsystem nfulnl_subsys = {
870 .name = "log",
871 .subsys_id = NFNL_SUBSYS_ULOG,
872 .cb_count = NFULNL_MSG_MAX,
873 .cb = nfulnl_cb,
874 };
875
876 #ifdef CONFIG_PROC_FS
877 struct iter_state {
878 unsigned int bucket;
879 };
880
881 static struct hlist_node *get_first(struct iter_state *st)
882 {
883 if (!st)
884 return NULL;
885
886 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
887 if (!hlist_empty(&instance_table[st->bucket]))
888 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
889 }
890 return NULL;
891 }
892
893 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
894 {
895 h = rcu_dereference_bh(hlist_next_rcu(h));
896 while (!h) {
897 if (++st->bucket >= INSTANCE_BUCKETS)
898 return NULL;
899
900 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
901 }
902 return h;
903 }
904
905 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
906 {
907 struct hlist_node *head;
908 head = get_first(st);
909
910 if (head)
911 while (pos && (head = get_next(st, head)))
912 pos--;
913 return pos ? NULL : head;
914 }
915
916 static void *seq_start(struct seq_file *seq, loff_t *pos)
917 __acquires(rcu_bh)
918 {
919 rcu_read_lock_bh();
920 return get_idx(seq->private, *pos);
921 }
922
923 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
924 {
925 (*pos)++;
926 return get_next(s->private, v);
927 }
928
929 static void seq_stop(struct seq_file *s, void *v)
930 __releases(rcu_bh)
931 {
932 rcu_read_unlock_bh();
933 }
934
935 static int seq_show(struct seq_file *s, void *v)
936 {
937 const struct nfulnl_instance *inst = v;
938
939 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
940 inst->group_num,
941 inst->peer_pid, inst->qlen,
942 inst->copy_mode, inst->copy_range,
943 inst->flushtimeout, atomic_read(&inst->use));
944 }
945
946 static const struct seq_operations nful_seq_ops = {
947 .start = seq_start,
948 .next = seq_next,
949 .stop = seq_stop,
950 .show = seq_show,
951 };
952
953 static int nful_open(struct inode *inode, struct file *file)
954 {
955 return seq_open_private(file, &nful_seq_ops,
956 sizeof(struct iter_state));
957 }
958
959 static const struct file_operations nful_file_ops = {
960 .owner = THIS_MODULE,
961 .open = nful_open,
962 .read = seq_read,
963 .llseek = seq_lseek,
964 .release = seq_release_private,
965 };
966
967 #endif /* PROC_FS */
968
969 static int __init nfnetlink_log_init(void)
970 {
971 int i, status = -ENOMEM;
972
973 for (i = 0; i < INSTANCE_BUCKETS; i++)
974 INIT_HLIST_HEAD(&instance_table[i]);
975
976 /* it's not really all that important to have a random value, so
977 * we can do this from the init function, even if there hasn't
978 * been that much entropy yet */
979 get_random_bytes(&hash_init, sizeof(hash_init));
980
981 netlink_register_notifier(&nfulnl_rtnl_notifier);
982 status = nfnetlink_subsys_register(&nfulnl_subsys);
983 if (status < 0) {
984 printk(KERN_ERR "log: failed to create netlink socket\n");
985 goto cleanup_netlink_notifier;
986 }
987
988 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
989 if (status < 0) {
990 printk(KERN_ERR "log: failed to register logger\n");
991 goto cleanup_subsys;
992 }
993
994 #ifdef CONFIG_PROC_FS
995 if (!proc_create("nfnetlink_log", 0440,
996 proc_net_netfilter, &nful_file_ops))
997 goto cleanup_logger;
998 #endif
999 return status;
1000
1001 #ifdef CONFIG_PROC_FS
1002 cleanup_logger:
1003 nf_log_unregister(&nfulnl_logger);
1004 #endif
1005 cleanup_subsys:
1006 nfnetlink_subsys_unregister(&nfulnl_subsys);
1007 cleanup_netlink_notifier:
1008 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1009 return status;
1010 }
1011
1012 static void __exit nfnetlink_log_fini(void)
1013 {
1014 nf_log_unregister(&nfulnl_logger);
1015 #ifdef CONFIG_PROC_FS
1016 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1017 #endif
1018 nfnetlink_subsys_unregister(&nfulnl_subsys);
1019 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1020 }
1021
1022 MODULE_DESCRIPTION("netfilter userspace logging");
1023 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1024 MODULE_LICENSE("GPL");
1025 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1026
1027 module_init(nfnetlink_log_init);
1028 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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