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Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[mirror_ubuntu-zesty-kernel.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 <net/sock.h>
32
33 #include <asm/atomic.h>
34
35 #ifdef CONFIG_BRIDGE_NETFILTER
36 #include "../bridge/br_private.h"
37 #endif
38
39 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
40 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
41 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
42
43 #define PRINTR(x, args...) do { if (net_ratelimit()) \
44 printk(x, ## args); } while (0);
45
46 #if 0
47 #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
48 __FILE__, __LINE__, __FUNCTION__, \
49 ## args)
50 #else
51 #define UDEBUG(x, ...)
52 #endif
53
54 struct nfulnl_instance {
55 struct hlist_node hlist; /* global list of instances */
56 spinlock_t lock;
57 atomic_t use; /* use count */
58
59 unsigned int qlen; /* number of nlmsgs in skb */
60 struct sk_buff *skb; /* pre-allocatd skb */
61 struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
62 struct timer_list timer;
63 int peer_pid; /* PID of the peer process */
64
65 /* configurable parameters */
66 unsigned int flushtimeout; /* timeout until queue flush */
67 unsigned int nlbufsiz; /* netlink buffer allocation size */
68 unsigned int qthreshold; /* threshold of the queue */
69 u_int32_t copy_range;
70 u_int32_t seq; /* instance-local sequential counter */
71 u_int16_t group_num; /* number of this queue */
72 u_int16_t flags;
73 u_int8_t copy_mode;
74 };
75
76 static DEFINE_RWLOCK(instances_lock);
77 static atomic_t global_seq;
78
79 #define INSTANCE_BUCKETS 16
80 static struct hlist_head instance_table[INSTANCE_BUCKETS];
81 static unsigned int hash_init;
82
83 static inline u_int8_t instance_hashfn(u_int16_t group_num)
84 {
85 return ((group_num & 0xff) % INSTANCE_BUCKETS);
86 }
87
88 static struct nfulnl_instance *
89 __instance_lookup(u_int16_t group_num)
90 {
91 struct hlist_head *head;
92 struct hlist_node *pos;
93 struct nfulnl_instance *inst;
94
95 UDEBUG("entering (group_num=%u)\n", group_num);
96
97 head = &instance_table[instance_hashfn(group_num)];
98 hlist_for_each_entry(inst, pos, head, hlist) {
99 if (inst->group_num == group_num)
100 return inst;
101 }
102 return NULL;
103 }
104
105 static inline void
106 instance_get(struct nfulnl_instance *inst)
107 {
108 atomic_inc(&inst->use);
109 }
110
111 static struct nfulnl_instance *
112 instance_lookup_get(u_int16_t group_num)
113 {
114 struct nfulnl_instance *inst;
115
116 read_lock_bh(&instances_lock);
117 inst = __instance_lookup(group_num);
118 if (inst)
119 instance_get(inst);
120 read_unlock_bh(&instances_lock);
121
122 return inst;
123 }
124
125 static void
126 instance_put(struct nfulnl_instance *inst)
127 {
128 if (inst && atomic_dec_and_test(&inst->use)) {
129 UDEBUG("kfree(inst=%p)\n", inst);
130 kfree(inst);
131 module_put(THIS_MODULE);
132 }
133 }
134
135 static void nfulnl_timer(unsigned long data);
136
137 static struct nfulnl_instance *
138 instance_create(u_int16_t group_num, int pid)
139 {
140 struct nfulnl_instance *inst;
141
142 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
143 pid);
144
145 write_lock_bh(&instances_lock);
146 if (__instance_lookup(group_num)) {
147 inst = NULL;
148 UDEBUG("aborting, instance already exists\n");
149 goto out_unlock;
150 }
151
152 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
153 if (!inst)
154 goto out_unlock;
155
156 INIT_HLIST_NODE(&inst->hlist);
157 spin_lock_init(&inst->lock);
158 /* needs to be two, since we _put() after creation */
159 atomic_set(&inst->use, 2);
160
161 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
162
163 inst->peer_pid = pid;
164 inst->group_num = group_num;
165
166 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
167 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
168 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
169 inst->copy_mode = NFULNL_COPY_PACKET;
170 inst->copy_range = 0xffff;
171
172 if (!try_module_get(THIS_MODULE))
173 goto out_free;
174
175 hlist_add_head(&inst->hlist,
176 &instance_table[instance_hashfn(group_num)]);
177
178 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
179 inst->hlist.next);
180
181 write_unlock_bh(&instances_lock);
182
183 return inst;
184
185 out_free:
186 instance_put(inst);
187 out_unlock:
188 write_unlock_bh(&instances_lock);
189 return NULL;
190 }
191
192 static int __nfulnl_send(struct nfulnl_instance *inst);
193
194 static void
195 __instance_destroy(struct nfulnl_instance *inst)
196 {
197 /* first pull it out of the global list */
198 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
199 inst, inst->group_num);
200
201 hlist_del(&inst->hlist);
202
203 /* then flush all pending packets from skb */
204
205 spin_lock_bh(&inst->lock);
206 if (inst->skb) {
207 /* timer "holds" one reference (we have one more) */
208 if (del_timer(&inst->timer))
209 instance_put(inst);
210 if (inst->qlen)
211 __nfulnl_send(inst);
212 if (inst->skb) {
213 kfree_skb(inst->skb);
214 inst->skb = NULL;
215 }
216 }
217 spin_unlock_bh(&inst->lock);
218
219 /* and finally put the refcount */
220 instance_put(inst);
221 }
222
223 static inline void
224 instance_destroy(struct nfulnl_instance *inst)
225 {
226 write_lock_bh(&instances_lock);
227 __instance_destroy(inst);
228 write_unlock_bh(&instances_lock);
229 }
230
231 static int
232 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
233 unsigned int range)
234 {
235 int status = 0;
236
237 spin_lock_bh(&inst->lock);
238
239 switch (mode) {
240 case NFULNL_COPY_NONE:
241 case NFULNL_COPY_META:
242 inst->copy_mode = mode;
243 inst->copy_range = 0;
244 break;
245
246 case NFULNL_COPY_PACKET:
247 inst->copy_mode = mode;
248 /* we're using struct nfattr which has 16bit nfa_len */
249 if (range > 0xffff)
250 inst->copy_range = 0xffff;
251 else
252 inst->copy_range = range;
253 break;
254
255 default:
256 status = -EINVAL;
257 break;
258 }
259
260 spin_unlock_bh(&inst->lock);
261
262 return status;
263 }
264
265 static int
266 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
267 {
268 int status;
269
270 spin_lock_bh(&inst->lock);
271 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
272 status = -ERANGE;
273 else if (nlbufsiz > 131072)
274 status = -ERANGE;
275 else {
276 inst->nlbufsiz = nlbufsiz;
277 status = 0;
278 }
279 spin_unlock_bh(&inst->lock);
280
281 return status;
282 }
283
284 static int
285 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
286 {
287 spin_lock_bh(&inst->lock);
288 inst->flushtimeout = timeout;
289 spin_unlock_bh(&inst->lock);
290
291 return 0;
292 }
293
294 static int
295 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
296 {
297 spin_lock_bh(&inst->lock);
298 inst->qthreshold = qthresh;
299 spin_unlock_bh(&inst->lock);
300
301 return 0;
302 }
303
304 static int
305 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
306 {
307 spin_lock_bh(&inst->lock);
308 inst->flags = flags;
309 spin_unlock_bh(&inst->lock);
310
311 return 0;
312 }
313
314 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
315 unsigned int pkt_size)
316 {
317 struct sk_buff *skb;
318 unsigned int n;
319
320 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
321
322 /* alloc skb which should be big enough for a whole multipart
323 * message. WARNING: has to be <= 128k due to slab restrictions */
324
325 n = max(inst_size, pkt_size);
326 skb = alloc_skb(n, GFP_ATOMIC);
327 if (!skb) {
328 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
329 inst_size);
330
331 if (n > pkt_size) {
332 /* try to allocate only as much as we need for current
333 * packet */
334
335 skb = alloc_skb(pkt_size, GFP_ATOMIC);
336 if (!skb)
337 PRINTR("nfnetlink_log: can't even alloc %u "
338 "bytes\n", pkt_size);
339 }
340 }
341
342 return skb;
343 }
344
345 static int
346 __nfulnl_send(struct nfulnl_instance *inst)
347 {
348 int status;
349
350 if (inst->qlen > 1)
351 inst->lastnlh->nlmsg_type = NLMSG_DONE;
352
353 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
354 if (status < 0) {
355 UDEBUG("netlink_unicast() failed\n");
356 /* FIXME: statistics */
357 }
358
359 inst->qlen = 0;
360 inst->skb = NULL;
361 inst->lastnlh = NULL;
362
363 return status;
364 }
365
366 static void nfulnl_timer(unsigned long data)
367 {
368 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
369
370 UDEBUG("timer function called, flushing buffer\n");
371
372 spin_lock_bh(&inst->lock);
373 if (inst->skb)
374 __nfulnl_send(inst);
375 spin_unlock_bh(&inst->lock);
376 instance_put(inst);
377 }
378
379 /* This is an inline function, we don't really care about a long
380 * list of arguments */
381 static inline int
382 __build_packet_message(struct nfulnl_instance *inst,
383 const struct sk_buff *skb,
384 unsigned int data_len,
385 unsigned int pf,
386 unsigned int hooknum,
387 const struct net_device *indev,
388 const struct net_device *outdev,
389 const struct nf_loginfo *li,
390 const char *prefix, unsigned int plen)
391 {
392 struct nfulnl_msg_packet_hdr pmsg;
393 struct nlmsghdr *nlh;
394 struct nfgenmsg *nfmsg;
395 __be32 tmp_uint;
396 sk_buff_data_t old_tail = inst->skb->tail;
397
398 UDEBUG("entered\n");
399
400 nlh = NLMSG_PUT(inst->skb, 0, 0,
401 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
402 sizeof(struct nfgenmsg));
403 nfmsg = NLMSG_DATA(nlh);
404 nfmsg->nfgen_family = pf;
405 nfmsg->version = NFNETLINK_V0;
406 nfmsg->res_id = htons(inst->group_num);
407
408 pmsg.hw_protocol = skb->protocol;
409 pmsg.hook = hooknum;
410
411 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
412
413 if (prefix)
414 NFA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
415
416 if (indev) {
417 tmp_uint = htonl(indev->ifindex);
418 #ifndef CONFIG_BRIDGE_NETFILTER
419 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
420 &tmp_uint);
421 #else
422 if (pf == PF_BRIDGE) {
423 /* Case 1: outdev is physical input device, we need to
424 * look for bridge group (when called from
425 * netfilter_bridge) */
426 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
427 sizeof(tmp_uint), &tmp_uint);
428 /* this is the bridge group "brX" */
429 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
430 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
431 sizeof(tmp_uint), &tmp_uint);
432 } else {
433 /* Case 2: indev is bridge group, we need to look for
434 * physical device (when called from ipv4) */
435 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
436 sizeof(tmp_uint), &tmp_uint);
437 if (skb->nf_bridge && skb->nf_bridge->physindev) {
438 tmp_uint =
439 htonl(skb->nf_bridge->physindev->ifindex);
440 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
441 sizeof(tmp_uint), &tmp_uint);
442 }
443 }
444 #endif
445 }
446
447 if (outdev) {
448 tmp_uint = htonl(outdev->ifindex);
449 #ifndef CONFIG_BRIDGE_NETFILTER
450 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
451 &tmp_uint);
452 #else
453 if (pf == PF_BRIDGE) {
454 /* Case 1: outdev is physical output device, we need to
455 * look for bridge group (when called from
456 * netfilter_bridge) */
457 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
458 sizeof(tmp_uint), &tmp_uint);
459 /* this is the bridge group "brX" */
460 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
461 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
462 sizeof(tmp_uint), &tmp_uint);
463 } else {
464 /* Case 2: indev is a bridge group, we need to look
465 * for physical device (when called from ipv4) */
466 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
467 sizeof(tmp_uint), &tmp_uint);
468 if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
469 tmp_uint =
470 htonl(skb->nf_bridge->physoutdev->ifindex);
471 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
472 sizeof(tmp_uint), &tmp_uint);
473 }
474 }
475 #endif
476 }
477
478 if (skb->mark) {
479 tmp_uint = htonl(skb->mark);
480 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
481 }
482
483 if (indev && skb->dev && skb->dev->hard_header_parse) {
484 struct nfulnl_msg_packet_hw phw;
485 int len = skb->dev->hard_header_parse((struct sk_buff *)skb,
486 phw.hw_addr);
487 phw.hw_addrlen = htons(len);
488 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
489 }
490
491 if (skb->tstamp.tv64) {
492 struct nfulnl_msg_packet_timestamp ts;
493 struct timeval tv = ktime_to_timeval(skb->tstamp);
494 ts.sec = cpu_to_be64(tv.tv_sec);
495 ts.usec = cpu_to_be64(tv.tv_usec);
496
497 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
498 }
499
500 /* UID */
501 if (skb->sk) {
502 read_lock_bh(&skb->sk->sk_callback_lock);
503 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
504 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
505 /* need to unlock here since NFA_PUT may goto */
506 read_unlock_bh(&skb->sk->sk_callback_lock);
507 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
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 tmp_uint = htonl(inst->seq++);
515 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
516 }
517 /* global sequence number */
518 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
519 tmp_uint = htonl(atomic_inc_return(&global_seq));
520 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
521 }
522
523 if (data_len) {
524 struct nfattr *nfa;
525 int size = NFA_LENGTH(data_len);
526
527 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
528 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
529 goto nlmsg_failure;
530 }
531
532 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
533 nfa->nfa_type = NFULA_PAYLOAD;
534 nfa->nfa_len = size;
535
536 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
537 BUG();
538 }
539
540 nlh->nlmsg_len = inst->skb->tail - old_tail;
541 inst->lastnlh = nlh;
542 return 0;
543
544 nlmsg_failure:
545 UDEBUG("nlmsg_failure\n");
546 nfattr_failure:
547 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
548 return -1;
549 }
550
551 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
552
553 static struct nf_loginfo default_loginfo = {
554 .type = NF_LOG_TYPE_ULOG,
555 .u = {
556 .ulog = {
557 .copy_len = 0xffff,
558 .group = 0,
559 .qthreshold = 1,
560 },
561 },
562 };
563
564 /* log handler for internal netfilter logging api */
565 static void
566 nfulnl_log_packet(unsigned int pf,
567 unsigned int hooknum,
568 const struct sk_buff *skb,
569 const struct net_device *in,
570 const struct net_device *out,
571 const struct nf_loginfo *li_user,
572 const char *prefix)
573 {
574 unsigned int size, data_len;
575 struct nfulnl_instance *inst;
576 const struct nf_loginfo *li;
577 unsigned int qthreshold;
578 unsigned int plen;
579
580 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
581 li = li_user;
582 else
583 li = &default_loginfo;
584
585 inst = instance_lookup_get(li->u.ulog.group);
586 if (!inst)
587 return;
588
589 plen = 0;
590 if (prefix)
591 plen = strlen(prefix) + 1;
592
593 /* all macros expand to constant values at compile time */
594 /* FIXME: do we want to make the size calculation conditional based on
595 * what is actually present? way more branches and checks, but more
596 * memory efficient... */
597 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
598 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
599 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
600 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
601 #ifdef CONFIG_BRIDGE_NETFILTER
602 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
603 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
604 #endif
605 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
606 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
607 + NFA_SPACE(plen) /* prefix */
608 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
609 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
610
611 UDEBUG("initial size=%u\n", size);
612
613 spin_lock_bh(&inst->lock);
614
615 if (inst->flags & NFULNL_CFG_F_SEQ)
616 size += NFA_SPACE(sizeof(u_int32_t));
617 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
618 size += NFA_SPACE(sizeof(u_int32_t));
619
620 qthreshold = inst->qthreshold;
621 /* per-rule qthreshold overrides per-instance */
622 if (qthreshold > li->u.ulog.qthreshold)
623 qthreshold = li->u.ulog.qthreshold;
624
625 switch (inst->copy_mode) {
626 case NFULNL_COPY_META:
627 case NFULNL_COPY_NONE:
628 data_len = 0;
629 break;
630
631 case NFULNL_COPY_PACKET:
632 if (inst->copy_range == 0
633 || inst->copy_range > skb->len)
634 data_len = skb->len;
635 else
636 data_len = inst->copy_range;
637
638 size += NFA_SPACE(data_len);
639 UDEBUG("copy_packet, therefore size now %u\n", size);
640 break;
641
642 default:
643 goto unlock_and_release;
644 }
645
646 if (inst->qlen >= qthreshold ||
647 (inst->skb && size > skb_tailroom(inst->skb))) {
648 /* either the queue len is too high or we don't have
649 * enough room in the skb left. flush to userspace. */
650 UDEBUG("flushing old skb\n");
651
652 /* timer "holds" one reference (we have another one) */
653 if (del_timer(&inst->timer))
654 instance_put(inst);
655 __nfulnl_send(inst);
656 }
657
658 if (!inst->skb) {
659 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
660 if (!inst->skb)
661 goto alloc_failure;
662 }
663
664 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
665 inst->qlen++;
666
667 __build_packet_message(inst, skb, data_len, pf,
668 hooknum, in, out, li, prefix, plen);
669
670 /* timer_pending always called within inst->lock, so there
671 * is no chance of a race here */
672 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 UDEBUG("error allocating skb\n");
685 /* FIXME: statistics */
686 goto unlock_and_release;
687 }
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 &&
696 n->protocol == NETLINK_NETFILTER && n->pid) {
697 int i;
698
699 /* destroy all instances for this pid */
700 write_lock_bh(&instances_lock);
701 for (i = 0; i < INSTANCE_BUCKETS; i++) {
702 struct hlist_node *tmp, *t2;
703 struct nfulnl_instance *inst;
704 struct hlist_head *head = &instance_table[i];
705
706 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
707 UDEBUG("node = %p\n", inst);
708 if (n->pid == inst->peer_pid)
709 __instance_destroy(inst);
710 }
711 }
712 write_unlock_bh(&instances_lock);
713 }
714 return NOTIFY_DONE;
715 }
716
717 static struct notifier_block nfulnl_rtnl_notifier = {
718 .notifier_call = nfulnl_rcv_nl_event,
719 };
720
721 static int
722 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
723 struct nlmsghdr *nlh, struct nfattr *nfqa[])
724 {
725 return -ENOTSUPP;
726 }
727
728 static struct nf_logger nfulnl_logger = {
729 .name = "nfnetlink_log",
730 .logfn = &nfulnl_log_packet,
731 .me = THIS_MODULE,
732 };
733
734 static const int nfula_min[NFULA_MAX] = {
735 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
736 [NFULA_MARK-1] = sizeof(u_int32_t),
737 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
738 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
739 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
740 [NFULA_IFINDEX_PHYSINDEV-1] = sizeof(u_int32_t),
741 [NFULA_IFINDEX_PHYSOUTDEV-1] = sizeof(u_int32_t),
742 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
743 [NFULA_PAYLOAD-1] = 0,
744 [NFULA_PREFIX-1] = 0,
745 [NFULA_UID-1] = sizeof(u_int32_t),
746 [NFULA_SEQ-1] = sizeof(u_int32_t),
747 [NFULA_SEQ_GLOBAL-1] = sizeof(u_int32_t),
748 };
749
750 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
751 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
752 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
753 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
754 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
755 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
756 [NFULA_CFG_FLAGS-1] = sizeof(u_int16_t),
757 };
758
759 static int
760 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
761 struct nlmsghdr *nlh, struct nfattr *nfula[])
762 {
763 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
764 u_int16_t group_num = ntohs(nfmsg->res_id);
765 struct nfulnl_instance *inst;
766 int ret = 0;
767
768 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
769
770 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
771 UDEBUG("bad attribute size\n");
772 return -EINVAL;
773 }
774
775 inst = instance_lookup_get(group_num);
776 if (nfula[NFULA_CFG_CMD-1]) {
777 u_int8_t pf = nfmsg->nfgen_family;
778 struct nfulnl_msg_config_cmd *cmd;
779 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
780 UDEBUG("found CFG_CMD for\n");
781
782 switch (cmd->command) {
783 case NFULNL_CFG_CMD_BIND:
784 if (inst) {
785 ret = -EBUSY;
786 goto out_put;
787 }
788
789 inst = instance_create(group_num,
790 NETLINK_CB(skb).pid);
791 if (!inst) {
792 ret = -EINVAL;
793 goto out;
794 }
795 break;
796 case NFULNL_CFG_CMD_UNBIND:
797 if (!inst) {
798 ret = -ENODEV;
799 goto out;
800 }
801
802 if (inst->peer_pid != NETLINK_CB(skb).pid) {
803 ret = -EPERM;
804 goto out_put;
805 }
806
807 instance_destroy(inst);
808 goto out;
809 case NFULNL_CFG_CMD_PF_BIND:
810 UDEBUG("registering log handler for pf=%u\n", pf);
811 ret = nf_log_register(pf, &nfulnl_logger);
812 break;
813 case NFULNL_CFG_CMD_PF_UNBIND:
814 UDEBUG("unregistering log handler for pf=%u\n", pf);
815 /* This is a bug and a feature. We cannot unregister
816 * other handlers, like nfnetlink_inst can */
817 nf_log_unregister_pf(pf);
818 break;
819 default:
820 ret = -EINVAL;
821 break;
822 }
823
824 if (!inst)
825 goto out;
826 } else {
827 if (!inst) {
828 UDEBUG("no config command, and no instance for "
829 "group=%u pid=%u =>ENOENT\n",
830 group_num, NETLINK_CB(skb).pid);
831 ret = -ENOENT;
832 goto out;
833 }
834
835 if (inst->peer_pid != NETLINK_CB(skb).pid) {
836 UDEBUG("no config command, and wrong pid\n");
837 ret = -EPERM;
838 goto out_put;
839 }
840 }
841
842 if (nfula[NFULA_CFG_MODE-1]) {
843 struct nfulnl_msg_config_mode *params;
844 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
845
846 nfulnl_set_mode(inst, params->copy_mode,
847 ntohl(params->copy_range));
848 }
849
850 if (nfula[NFULA_CFG_TIMEOUT-1]) {
851 __be32 timeout =
852 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
853
854 nfulnl_set_timeout(inst, ntohl(timeout));
855 }
856
857 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
858 __be32 nlbufsiz =
859 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
860
861 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
862 }
863
864 if (nfula[NFULA_CFG_QTHRESH-1]) {
865 __be32 qthresh =
866 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
867
868 nfulnl_set_qthresh(inst, ntohl(qthresh));
869 }
870
871 if (nfula[NFULA_CFG_FLAGS-1]) {
872 __be16 flags =
873 *(__be16 *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
874 nfulnl_set_flags(inst, ntohs(flags));
875 }
876
877 out_put:
878 instance_put(inst);
879 out:
880 return ret;
881 }
882
883 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
884 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
885 .attr_count = NFULA_MAX, },
886 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
887 .attr_count = NFULA_CFG_MAX, },
888 };
889
890 static struct nfnetlink_subsystem nfulnl_subsys = {
891 .name = "log",
892 .subsys_id = NFNL_SUBSYS_ULOG,
893 .cb_count = NFULNL_MSG_MAX,
894 .cb = nfulnl_cb,
895 };
896
897 #ifdef CONFIG_PROC_FS
898 struct iter_state {
899 unsigned int bucket;
900 };
901
902 static struct hlist_node *get_first(struct iter_state *st)
903 {
904 if (!st)
905 return NULL;
906
907 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
908 if (!hlist_empty(&instance_table[st->bucket]))
909 return instance_table[st->bucket].first;
910 }
911 return NULL;
912 }
913
914 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
915 {
916 h = h->next;
917 while (!h) {
918 if (++st->bucket >= INSTANCE_BUCKETS)
919 return NULL;
920
921 h = instance_table[st->bucket].first;
922 }
923 return h;
924 }
925
926 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
927 {
928 struct hlist_node *head;
929 head = get_first(st);
930
931 if (head)
932 while (pos && (head = get_next(st, head)))
933 pos--;
934 return pos ? NULL : head;
935 }
936
937 static void *seq_start(struct seq_file *seq, loff_t *pos)
938 {
939 read_lock_bh(&instances_lock);
940 return get_idx(seq->private, *pos);
941 }
942
943 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
944 {
945 (*pos)++;
946 return get_next(s->private, v);
947 }
948
949 static void seq_stop(struct seq_file *s, void *v)
950 {
951 read_unlock_bh(&instances_lock);
952 }
953
954 static int seq_show(struct seq_file *s, void *v)
955 {
956 const struct nfulnl_instance *inst = v;
957
958 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
959 inst->group_num,
960 inst->peer_pid, inst->qlen,
961 inst->copy_mode, inst->copy_range,
962 inst->flushtimeout, atomic_read(&inst->use));
963 }
964
965 static struct seq_operations nful_seq_ops = {
966 .start = seq_start,
967 .next = seq_next,
968 .stop = seq_stop,
969 .show = seq_show,
970 };
971
972 static int nful_open(struct inode *inode, struct file *file)
973 {
974 struct seq_file *seq;
975 struct iter_state *is;
976 int ret;
977
978 is = kzalloc(sizeof(*is), GFP_KERNEL);
979 if (!is)
980 return -ENOMEM;
981 ret = seq_open(file, &nful_seq_ops);
982 if (ret < 0)
983 goto out_free;
984 seq = file->private_data;
985 seq->private = is;
986 return ret;
987 out_free:
988 kfree(is);
989 return ret;
990 }
991
992 static const struct file_operations nful_file_ops = {
993 .owner = THIS_MODULE,
994 .open = nful_open,
995 .read = seq_read,
996 .llseek = seq_lseek,
997 .release = seq_release_private,
998 };
999
1000 #endif /* PROC_FS */
1001
1002 static int __init nfnetlink_log_init(void)
1003 {
1004 int i, status = -ENOMEM;
1005 #ifdef CONFIG_PROC_FS
1006 struct proc_dir_entry *proc_nful;
1007 #endif
1008
1009 for (i = 0; i < INSTANCE_BUCKETS; i++)
1010 INIT_HLIST_HEAD(&instance_table[i]);
1011
1012 /* it's not really all that important to have a random value, so
1013 * we can do this from the init function, even if there hasn't
1014 * been that much entropy yet */
1015 get_random_bytes(&hash_init, sizeof(hash_init));
1016
1017 netlink_register_notifier(&nfulnl_rtnl_notifier);
1018 status = nfnetlink_subsys_register(&nfulnl_subsys);
1019 if (status < 0) {
1020 printk(KERN_ERR "log: failed to create netlink socket\n");
1021 goto cleanup_netlink_notifier;
1022 }
1023
1024 #ifdef CONFIG_PROC_FS
1025 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1026 proc_net_netfilter);
1027 if (!proc_nful)
1028 goto cleanup_subsys;
1029 proc_nful->proc_fops = &nful_file_ops;
1030 #endif
1031 return status;
1032
1033 #ifdef CONFIG_PROC_FS
1034 cleanup_subsys:
1035 nfnetlink_subsys_unregister(&nfulnl_subsys);
1036 #endif
1037 cleanup_netlink_notifier:
1038 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1039 return status;
1040 }
1041
1042 static void __exit nfnetlink_log_fini(void)
1043 {
1044 nf_log_unregister(&nfulnl_logger);
1045 #ifdef CONFIG_PROC_FS
1046 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1047 #endif
1048 nfnetlink_subsys_unregister(&nfulnl_subsys);
1049 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1050 }
1051
1052 MODULE_DESCRIPTION("netfilter userspace logging");
1053 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1054 MODULE_LICENSE("GPL");
1055 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1056
1057 module_init(nfnetlink_log_init);
1058 module_exit(nfnetlink_log_fini);
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