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[NETFILTER]: nfnetlink_{queue,log}: return ENOTSUPP for unknown cfg commands
[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 <net/sock.h>
32 #include <net/netfilter/nf_log.h>
33
34 #include <asm/atomic.h>
35
36 #ifdef CONFIG_BRIDGE_NETFILTER
37 #include "../bridge/br_private.h"
38 #endif
39
40 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
41 #define NFULNL_TIMEOUT_DEFAULT HZ /* every second */
42 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
43 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
44
45 #define PRINTR(x, args...) do { if (net_ratelimit()) \
46 printk(x, ## args); } while (0);
47
48 #if 0
49 #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
50 __FILE__, __LINE__, __FUNCTION__, \
51 ## args)
52 #else
53 #define UDEBUG(x, ...)
54 #endif
55
56 struct nfulnl_instance {
57 struct hlist_node hlist; /* global list of instances */
58 spinlock_t lock;
59 atomic_t use; /* use count */
60
61 unsigned int qlen; /* number of nlmsgs in skb */
62 struct sk_buff *skb; /* pre-allocatd skb */
63 struct timer_list timer;
64 int peer_pid; /* PID of the peer process */
65
66 /* configurable parameters */
67 unsigned int flushtimeout; /* timeout until queue flush */
68 unsigned int nlbufsiz; /* netlink buffer allocation size */
69 unsigned int qthreshold; /* threshold of the queue */
70 u_int32_t copy_range;
71 u_int32_t seq; /* instance-local sequential counter */
72 u_int16_t group_num; /* number of this queue */
73 u_int16_t flags;
74 u_int8_t copy_mode;
75 };
76
77 static DEFINE_RWLOCK(instances_lock);
78 static atomic_t global_seq;
79
80 #define INSTANCE_BUCKETS 16
81 static struct hlist_head instance_table[INSTANCE_BUCKETS];
82 static unsigned int hash_init;
83
84 static inline u_int8_t instance_hashfn(u_int16_t group_num)
85 {
86 return ((group_num & 0xff) % INSTANCE_BUCKETS);
87 }
88
89 static struct nfulnl_instance *
90 __instance_lookup(u_int16_t group_num)
91 {
92 struct hlist_head *head;
93 struct hlist_node *pos;
94 struct nfulnl_instance *inst;
95
96 UDEBUG("entering (group_num=%u)\n", group_num);
97
98 head = &instance_table[instance_hashfn(group_num)];
99 hlist_for_each_entry(inst, pos, head, hlist) {
100 if (inst->group_num == group_num)
101 return inst;
102 }
103 return NULL;
104 }
105
106 static inline void
107 instance_get(struct nfulnl_instance *inst)
108 {
109 atomic_inc(&inst->use);
110 }
111
112 static struct nfulnl_instance *
113 instance_lookup_get(u_int16_t group_num)
114 {
115 struct nfulnl_instance *inst;
116
117 read_lock_bh(&instances_lock);
118 inst = __instance_lookup(group_num);
119 if (inst)
120 instance_get(inst);
121 read_unlock_bh(&instances_lock);
122
123 return inst;
124 }
125
126 static void
127 instance_put(struct nfulnl_instance *inst)
128 {
129 if (inst && atomic_dec_and_test(&inst->use)) {
130 UDEBUG("kfree(inst=%p)\n", inst);
131 kfree(inst);
132 module_put(THIS_MODULE);
133 }
134 }
135
136 static void nfulnl_timer(unsigned long data);
137
138 static struct nfulnl_instance *
139 instance_create(u_int16_t group_num, int pid)
140 {
141 struct nfulnl_instance *inst;
142
143 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
144 pid);
145
146 write_lock_bh(&instances_lock);
147 if (__instance_lookup(group_num)) {
148 inst = NULL;
149 UDEBUG("aborting, instance already exists\n");
150 goto out_unlock;
151 }
152
153 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
154 if (!inst)
155 goto out_unlock;
156
157 if (!try_module_get(THIS_MODULE)) {
158 kfree(inst);
159 goto out_unlock;
160 }
161
162 INIT_HLIST_NODE(&inst->hlist);
163 spin_lock_init(&inst->lock);
164 /* needs to be two, since we _put() after creation */
165 atomic_set(&inst->use, 2);
166
167 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
168
169 inst->peer_pid = pid;
170 inst->group_num = group_num;
171
172 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
173 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
174 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
175 inst->copy_mode = NFULNL_COPY_PACKET;
176 inst->copy_range = NFULNL_COPY_RANGE_MAX;
177
178 hlist_add_head(&inst->hlist,
179 &instance_table[instance_hashfn(group_num)]);
180
181 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
182 inst->hlist.next);
183
184 write_unlock_bh(&instances_lock);
185
186 return inst;
187
188 out_unlock:
189 write_unlock_bh(&instances_lock);
190 return NULL;
191 }
192
193 static void __nfulnl_flush(struct nfulnl_instance *inst);
194
195 static void
196 __instance_destroy(struct nfulnl_instance *inst)
197 {
198 /* first pull it out of the global list */
199 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
200 inst, inst->group_num);
201
202 hlist_del(&inst->hlist);
203
204 /* then flush all pending packets from skb */
205
206 spin_lock_bh(&inst->lock);
207 if (inst->skb)
208 __nfulnl_flush(inst);
209 spin_unlock_bh(&inst->lock);
210
211 /* and finally put the refcount */
212 instance_put(inst);
213 }
214
215 static inline void
216 instance_destroy(struct nfulnl_instance *inst)
217 {
218 write_lock_bh(&instances_lock);
219 __instance_destroy(inst);
220 write_unlock_bh(&instances_lock);
221 }
222
223 static int
224 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
225 unsigned int range)
226 {
227 int status = 0;
228
229 spin_lock_bh(&inst->lock);
230
231 switch (mode) {
232 case NFULNL_COPY_NONE:
233 case NFULNL_COPY_META:
234 inst->copy_mode = mode;
235 inst->copy_range = 0;
236 break;
237
238 case NFULNL_COPY_PACKET:
239 inst->copy_mode = mode;
240 inst->copy_range = min_t(unsigned int,
241 range, NFULNL_COPY_RANGE_MAX);
242 break;
243
244 default:
245 status = -EINVAL;
246 break;
247 }
248
249 spin_unlock_bh(&inst->lock);
250
251 return status;
252 }
253
254 static int
255 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
256 {
257 int status;
258
259 spin_lock_bh(&inst->lock);
260 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
261 status = -ERANGE;
262 else if (nlbufsiz > 131072)
263 status = -ERANGE;
264 else {
265 inst->nlbufsiz = nlbufsiz;
266 status = 0;
267 }
268 spin_unlock_bh(&inst->lock);
269
270 return status;
271 }
272
273 static int
274 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
275 {
276 spin_lock_bh(&inst->lock);
277 inst->flushtimeout = timeout;
278 spin_unlock_bh(&inst->lock);
279
280 return 0;
281 }
282
283 static int
284 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
285 {
286 spin_lock_bh(&inst->lock);
287 inst->qthreshold = qthresh;
288 spin_unlock_bh(&inst->lock);
289
290 return 0;
291 }
292
293 static int
294 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
295 {
296 spin_lock_bh(&inst->lock);
297 inst->flags = flags;
298 spin_unlock_bh(&inst->lock);
299
300 return 0;
301 }
302
303 static struct sk_buff *
304 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
305 {
306 struct sk_buff *skb;
307 unsigned int n;
308
309 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
310
311 /* alloc skb which should be big enough for a whole multipart
312 * message. WARNING: has to be <= 128k due to slab restrictions */
313
314 n = max(inst_size, pkt_size);
315 skb = alloc_skb(n, GFP_ATOMIC);
316 if (!skb) {
317 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
318 inst_size);
319
320 if (n > pkt_size) {
321 /* try to allocate only as much as we need for current
322 * packet */
323
324 skb = alloc_skb(pkt_size, GFP_ATOMIC);
325 if (!skb)
326 PRINTR("nfnetlink_log: can't even alloc %u "
327 "bytes\n", pkt_size);
328 }
329 }
330
331 return skb;
332 }
333
334 static int
335 __nfulnl_send(struct nfulnl_instance *inst)
336 {
337 int status = -1;
338
339 if (inst->qlen > 1)
340 NLMSG_PUT(inst->skb, 0, 0,
341 NLMSG_DONE,
342 sizeof(struct nfgenmsg));
343
344 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
345 if (status < 0) {
346 UDEBUG("netlink_unicast() failed\n");
347 /* FIXME: statistics */
348 }
349
350 inst->qlen = 0;
351 inst->skb = NULL;
352
353 nlmsg_failure:
354 return status;
355 }
356
357 static void
358 __nfulnl_flush(struct nfulnl_instance *inst)
359 {
360 /* timer holds a reference */
361 if (del_timer(&inst->timer))
362 instance_put(inst);
363 if (inst->skb)
364 __nfulnl_send(inst);
365 }
366
367 static void
368 nfulnl_timer(unsigned long data)
369 {
370 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
371
372 UDEBUG("timer function called, flushing buffer\n");
373
374 spin_lock_bh(&inst->lock);
375 if (inst->skb)
376 __nfulnl_send(inst);
377 spin_unlock_bh(&inst->lock);
378 instance_put(inst);
379 }
380
381 /* This is an inline function, we don't really care about a long
382 * list of arguments */
383 static inline int
384 __build_packet_message(struct nfulnl_instance *inst,
385 const struct sk_buff *skb,
386 unsigned int data_len,
387 unsigned int pf,
388 unsigned int hooknum,
389 const struct net_device *indev,
390 const struct net_device *outdev,
391 const struct nf_loginfo *li,
392 const char *prefix, unsigned int plen)
393 {
394 struct nfulnl_msg_packet_hdr pmsg;
395 struct nlmsghdr *nlh;
396 struct nfgenmsg *nfmsg;
397 __be32 tmp_uint;
398 sk_buff_data_t old_tail = inst->skb->tail;
399
400 UDEBUG("entered\n");
401
402 nlh = NLMSG_PUT(inst->skb, 0, 0,
403 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
404 sizeof(struct nfgenmsg));
405 nfmsg = NLMSG_DATA(nlh);
406 nfmsg->nfgen_family = pf;
407 nfmsg->version = NFNETLINK_V0;
408 nfmsg->res_id = htons(inst->group_num);
409
410 pmsg.hw_protocol = skb->protocol;
411 pmsg.hook = hooknum;
412
413 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
414
415 if (prefix)
416 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
417
418 if (indev) {
419 tmp_uint = htonl(indev->ifindex);
420 #ifndef CONFIG_BRIDGE_NETFILTER
421 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
422 &tmp_uint);
423 #else
424 if (pf == PF_BRIDGE) {
425 /* Case 1: outdev is physical input device, we need to
426 * look for bridge group (when called from
427 * netfilter_bridge) */
428 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
429 sizeof(tmp_uint), &tmp_uint);
430 /* this is the bridge group "brX" */
431 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
432 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
433 sizeof(tmp_uint), &tmp_uint);
434 } else {
435 /* Case 2: indev is bridge group, we need to look for
436 * physical device (when called from ipv4) */
437 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
438 sizeof(tmp_uint), &tmp_uint);
439 if (skb->nf_bridge && skb->nf_bridge->physindev) {
440 tmp_uint =
441 htonl(skb->nf_bridge->physindev->ifindex);
442 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
443 sizeof(tmp_uint), &tmp_uint);
444 }
445 }
446 #endif
447 }
448
449 if (outdev) {
450 tmp_uint = htonl(outdev->ifindex);
451 #ifndef CONFIG_BRIDGE_NETFILTER
452 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
453 &tmp_uint);
454 #else
455 if (pf == PF_BRIDGE) {
456 /* Case 1: outdev is physical output device, we need to
457 * look for bridge group (when called from
458 * netfilter_bridge) */
459 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
460 sizeof(tmp_uint), &tmp_uint);
461 /* this is the bridge group "brX" */
462 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
463 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
464 sizeof(tmp_uint), &tmp_uint);
465 } else {
466 /* Case 2: indev is a bridge group, we need to look
467 * for physical device (when called from ipv4) */
468 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
469 sizeof(tmp_uint), &tmp_uint);
470 if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
471 tmp_uint =
472 htonl(skb->nf_bridge->physoutdev->ifindex);
473 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
474 sizeof(tmp_uint), &tmp_uint);
475 }
476 }
477 #endif
478 }
479
480 if (skb->mark) {
481 tmp_uint = htonl(skb->mark);
482 NLA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
483 }
484
485 if (indev && skb->dev) {
486 struct nfulnl_msg_packet_hw phw;
487 int len = dev_parse_header(skb, phw.hw_addr);
488 if (len > 0) {
489 phw.hw_addrlen = htons(len);
490 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
491 }
492 }
493
494 if (skb->tstamp.tv64) {
495 struct nfulnl_msg_packet_timestamp ts;
496 struct timeval tv = ktime_to_timeval(skb->tstamp);
497 ts.sec = cpu_to_be64(tv.tv_sec);
498 ts.usec = cpu_to_be64(tv.tv_usec);
499
500 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
501 }
502
503 /* UID */
504 if (skb->sk) {
505 read_lock_bh(&skb->sk->sk_callback_lock);
506 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
507 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
508 /* need to unlock here since NLA_PUT may goto */
509 read_unlock_bh(&skb->sk->sk_callback_lock);
510 NLA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
511 } else
512 read_unlock_bh(&skb->sk->sk_callback_lock);
513 }
514
515 /* local sequence number */
516 if (inst->flags & NFULNL_CFG_F_SEQ) {
517 tmp_uint = htonl(inst->seq++);
518 NLA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
519 }
520 /* global sequence number */
521 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
522 tmp_uint = htonl(atomic_inc_return(&global_seq));
523 NLA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
524 }
525
526 if (data_len) {
527 struct nlattr *nla;
528 int size = nla_attr_size(data_len);
529
530 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
531 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
532 goto nlmsg_failure;
533 }
534
535 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
536 nla->nla_type = NFULA_PAYLOAD;
537 nla->nla_len = size;
538
539 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
540 BUG();
541 }
542
543 nlh->nlmsg_len = inst->skb->tail - old_tail;
544 return 0;
545
546 nlmsg_failure:
547 UDEBUG("nlmsg_failure\n");
548 nla_put_failure:
549 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
550 return -1;
551 }
552
553 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
554
555 static struct nf_loginfo default_loginfo = {
556 .type = NF_LOG_TYPE_ULOG,
557 .u = {
558 .ulog = {
559 .copy_len = 0xffff,
560 .group = 0,
561 .qthreshold = 1,
562 },
563 },
564 };
565
566 /* log handler for internal netfilter logging api */
567 static void
568 nfulnl_log_packet(unsigned int pf,
569 unsigned int hooknum,
570 const struct sk_buff *skb,
571 const struct net_device *in,
572 const struct net_device *out,
573 const struct nf_loginfo *li_user,
574 const char *prefix)
575 {
576 unsigned int size, data_len;
577 struct nfulnl_instance *inst;
578 const struct nf_loginfo *li;
579 unsigned int qthreshold;
580 unsigned int plen;
581
582 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
583 li = li_user;
584 else
585 li = &default_loginfo;
586
587 inst = instance_lookup_get(li->u.ulog.group);
588 if (!inst)
589 return;
590
591 plen = 0;
592 if (prefix)
593 plen = strlen(prefix) + 1;
594
595 /* FIXME: do we want to make the size calculation conditional based on
596 * what is actually present? way more branches and checks, but more
597 * memory efficient... */
598 size = NLMSG_ALIGN(sizeof(struct nfgenmsg))
599 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
600 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
601 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
602 #ifdef CONFIG_BRIDGE_NETFILTER
603 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
604 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
605 #endif
606 + nla_total_size(sizeof(u_int32_t)) /* mark */
607 + nla_total_size(sizeof(u_int32_t)) /* uid */
608 + nla_total_size(plen) /* prefix */
609 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
610 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
611
612 UDEBUG("initial size=%u\n", size);
613
614 spin_lock_bh(&inst->lock);
615
616 if (inst->flags & NFULNL_CFG_F_SEQ)
617 size += nla_total_size(sizeof(u_int32_t));
618 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
619 size += nla_total_size(sizeof(u_int32_t));
620
621 qthreshold = inst->qthreshold;
622 /* per-rule qthreshold overrides per-instance */
623 if (qthreshold > li->u.ulog.qthreshold)
624 qthreshold = li->u.ulog.qthreshold;
625
626 switch (inst->copy_mode) {
627 case NFULNL_COPY_META:
628 case NFULNL_COPY_NONE:
629 data_len = 0;
630 break;
631
632 case NFULNL_COPY_PACKET:
633 if (inst->copy_range == 0
634 || inst->copy_range > skb->len)
635 data_len = skb->len;
636 else
637 data_len = inst->copy_range;
638
639 size += nla_total_size(data_len);
640 UDEBUG("copy_packet, therefore size now %u\n", size);
641 break;
642
643 default:
644 goto unlock_and_release;
645 }
646
647 if (inst->skb &&
648 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
649 /* either the queue len is too high or we don't have
650 * enough room in the skb left. flush to userspace. */
651 UDEBUG("flushing old skb\n");
652
653 __nfulnl_flush(inst);
654 }
655
656 if (!inst->skb) {
657 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
658 if (!inst->skb)
659 goto alloc_failure;
660 }
661
662 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
663 inst->qlen++;
664
665 __build_packet_message(inst, skb, data_len, pf,
666 hooknum, in, out, li, 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 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->net == &init_net) &&
709 (n->pid == inst->peer_pid))
710 __instance_destroy(inst);
711 }
712 }
713 write_unlock_bh(&instances_lock);
714 }
715 return NOTIFY_DONE;
716 }
717
718 static struct notifier_block nfulnl_rtnl_notifier = {
719 .notifier_call = nfulnl_rcv_nl_event,
720 };
721
722 static int
723 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
724 struct nlmsghdr *nlh, struct nlattr *nfqa[])
725 {
726 return -ENOTSUPP;
727 }
728
729 static const struct nf_logger nfulnl_logger = {
730 .name = "nfnetlink_log",
731 .logfn = &nfulnl_log_packet,
732 .me = THIS_MODULE,
733 };
734
735 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
736 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
737 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
738 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
739 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
740 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
741 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
742 };
743
744 static int
745 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
746 struct nlmsghdr *nlh, struct nlattr *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 int ret = 0;
752
753 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
754
755 inst = instance_lookup_get(group_num);
756 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
757 ret = -EPERM;
758 goto out_put;
759 }
760
761 if (nfula[NFULA_CFG_CMD]) {
762 u_int8_t pf = nfmsg->nfgen_family;
763 struct nfulnl_msg_config_cmd *cmd;
764
765 cmd = nla_data(nfula[NFULA_CFG_CMD]);
766 UDEBUG("found CFG_CMD for\n");
767
768 switch (cmd->command) {
769 case NFULNL_CFG_CMD_BIND:
770 if (inst) {
771 ret = -EBUSY;
772 goto out_put;
773 }
774
775 inst = instance_create(group_num,
776 NETLINK_CB(skb).pid);
777 if (!inst) {
778 ret = -EINVAL;
779 goto out;
780 }
781 break;
782 case NFULNL_CFG_CMD_UNBIND:
783 if (!inst) {
784 ret = -ENODEV;
785 goto out;
786 }
787
788 instance_destroy(inst);
789 goto out;
790 case NFULNL_CFG_CMD_PF_BIND:
791 UDEBUG("registering log handler for pf=%u\n", pf);
792 ret = nf_log_register(pf, &nfulnl_logger);
793 break;
794 case NFULNL_CFG_CMD_PF_UNBIND:
795 UDEBUG("unregistering log handler for pf=%u\n", pf);
796 /* This is a bug and a feature. We cannot unregister
797 * other handlers, like nfnetlink_inst can */
798 nf_log_unregister_pf(pf);
799 break;
800 default:
801 ret = -ENOTSUPP;
802 break;
803 }
804 }
805
806 if (nfula[NFULA_CFG_MODE]) {
807 struct nfulnl_msg_config_mode *params;
808 params = nla_data(nfula[NFULA_CFG_MODE]);
809
810 if (!inst) {
811 ret = -ENODEV;
812 goto out;
813 }
814 nfulnl_set_mode(inst, params->copy_mode,
815 ntohl(params->copy_range));
816 }
817
818 if (nfula[NFULA_CFG_TIMEOUT]) {
819 __be32 timeout =
820 *(__be32 *)nla_data(nfula[NFULA_CFG_TIMEOUT]);
821
822 if (!inst) {
823 ret = -ENODEV;
824 goto out;
825 }
826 nfulnl_set_timeout(inst, ntohl(timeout));
827 }
828
829 if (nfula[NFULA_CFG_NLBUFSIZ]) {
830 __be32 nlbufsiz =
831 *(__be32 *)nla_data(nfula[NFULA_CFG_NLBUFSIZ]);
832
833 if (!inst) {
834 ret = -ENODEV;
835 goto out;
836 }
837 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
838 }
839
840 if (nfula[NFULA_CFG_QTHRESH]) {
841 __be32 qthresh =
842 *(__be32 *)nla_data(nfula[NFULA_CFG_QTHRESH]);
843
844 if (!inst) {
845 ret = -ENODEV;
846 goto out;
847 }
848 nfulnl_set_qthresh(inst, ntohl(qthresh));
849 }
850
851 if (nfula[NFULA_CFG_FLAGS]) {
852 __be16 flags =
853 *(__be16 *)nla_data(nfula[NFULA_CFG_FLAGS]);
854
855 if (!inst) {
856 ret = -ENODEV;
857 goto out;
858 }
859 nfulnl_set_flags(inst, ntohs(flags));
860 }
861
862 out_put:
863 instance_put(inst);
864 out:
865 return ret;
866 }
867
868 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
869 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
870 .attr_count = NFULA_MAX, },
871 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
872 .attr_count = NFULA_CFG_MAX,
873 .policy = nfula_cfg_policy },
874 };
875
876 static const struct nfnetlink_subsystem nfulnl_subsys = {
877 .name = "log",
878 .subsys_id = NFNL_SUBSYS_ULOG,
879 .cb_count = NFULNL_MSG_MAX,
880 .cb = nfulnl_cb,
881 };
882
883 #ifdef CONFIG_PROC_FS
884 struct iter_state {
885 unsigned int bucket;
886 };
887
888 static struct hlist_node *get_first(struct iter_state *st)
889 {
890 if (!st)
891 return NULL;
892
893 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
894 if (!hlist_empty(&instance_table[st->bucket]))
895 return instance_table[st->bucket].first;
896 }
897 return NULL;
898 }
899
900 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
901 {
902 h = h->next;
903 while (!h) {
904 if (++st->bucket >= INSTANCE_BUCKETS)
905 return NULL;
906
907 h = instance_table[st->bucket].first;
908 }
909 return h;
910 }
911
912 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
913 {
914 struct hlist_node *head;
915 head = get_first(st);
916
917 if (head)
918 while (pos && (head = get_next(st, head)))
919 pos--;
920 return pos ? NULL : head;
921 }
922
923 static void *seq_start(struct seq_file *seq, loff_t *pos)
924 {
925 read_lock_bh(&instances_lock);
926 return get_idx(seq->private, *pos);
927 }
928
929 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
930 {
931 (*pos)++;
932 return get_next(s->private, v);
933 }
934
935 static void seq_stop(struct seq_file *s, void *v)
936 {
937 read_unlock_bh(&instances_lock);
938 }
939
940 static int seq_show(struct seq_file *s, void *v)
941 {
942 const struct nfulnl_instance *inst = v;
943
944 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
945 inst->group_num,
946 inst->peer_pid, inst->qlen,
947 inst->copy_mode, inst->copy_range,
948 inst->flushtimeout, atomic_read(&inst->use));
949 }
950
951 static const struct seq_operations nful_seq_ops = {
952 .start = seq_start,
953 .next = seq_next,
954 .stop = seq_stop,
955 .show = seq_show,
956 };
957
958 static int nful_open(struct inode *inode, struct file *file)
959 {
960 return seq_open_private(file, &nful_seq_ops,
961 sizeof(struct iter_state));
962 }
963
964 static const struct file_operations nful_file_ops = {
965 .owner = THIS_MODULE,
966 .open = nful_open,
967 .read = seq_read,
968 .llseek = seq_lseek,
969 .release = seq_release_private,
970 };
971
972 #endif /* PROC_FS */
973
974 static int __init nfnetlink_log_init(void)
975 {
976 int i, status = -ENOMEM;
977 #ifdef CONFIG_PROC_FS
978 struct proc_dir_entry *proc_nful;
979 #endif
980
981 for (i = 0; i < INSTANCE_BUCKETS; i++)
982 INIT_HLIST_HEAD(&instance_table[i]);
983
984 /* it's not really all that important to have a random value, so
985 * we can do this from the init function, even if there hasn't
986 * been that much entropy yet */
987 get_random_bytes(&hash_init, sizeof(hash_init));
988
989 netlink_register_notifier(&nfulnl_rtnl_notifier);
990 status = nfnetlink_subsys_register(&nfulnl_subsys);
991 if (status < 0) {
992 printk(KERN_ERR "log: failed to create netlink socket\n");
993 goto cleanup_netlink_notifier;
994 }
995
996 #ifdef CONFIG_PROC_FS
997 proc_nful = create_proc_entry("nfnetlink_log", 0440,
998 proc_net_netfilter);
999 if (!proc_nful)
1000 goto cleanup_subsys;
1001 proc_nful->proc_fops = &nful_file_ops;
1002 #endif
1003 return status;
1004
1005 #ifdef CONFIG_PROC_FS
1006 cleanup_subsys:
1007 nfnetlink_subsys_unregister(&nfulnl_subsys);
1008 #endif
1009 cleanup_netlink_notifier:
1010 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1011 return status;
1012 }
1013
1014 static void __exit nfnetlink_log_fini(void)
1015 {
1016 nf_log_unregister(&nfulnl_logger);
1017 #ifdef CONFIG_PROC_FS
1018 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1019 #endif
1020 nfnetlink_subsys_unregister(&nfulnl_subsys);
1021 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1022 }
1023
1024 MODULE_DESCRIPTION("netfilter userspace logging");
1025 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1026 MODULE_LICENSE("GPL");
1027 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1028
1029 module_init(nfnetlink_log_init);
1030 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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