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Merge branch btrfs-master into for-linus
[mirror_ubuntu-bionic-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 #include <net/netfilter/nf_log.h>
33 #include <net/netfilter/nfnetlink_log.h>
34
35 #include <asm/atomic.h>
36
37 #ifdef CONFIG_BRIDGE_NETFILTER
38 #include "../bridge/br_private.h"
39 #endif
40
41 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
42 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
43 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
44 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
45
46 #define PRINTR(x, args...) do { if (net_ratelimit()) \
47 printk(x, ## args); } while (0);
48
49 struct nfulnl_instance {
50 struct hlist_node hlist; /* global list of instances */
51 spinlock_t lock;
52 atomic_t use; /* use count */
53
54 unsigned int qlen; /* number of nlmsgs in skb */
55 struct sk_buff *skb; /* pre-allocatd skb */
56 struct timer_list timer;
57 int peer_pid; /* PID of the peer process */
58
59 /* configurable parameters */
60 unsigned int flushtimeout; /* timeout until queue flush */
61 unsigned int nlbufsiz; /* netlink buffer allocation size */
62 unsigned int qthreshold; /* threshold of the queue */
63 u_int32_t copy_range;
64 u_int32_t seq; /* instance-local sequential counter */
65 u_int16_t group_num; /* number of this queue */
66 u_int16_t flags;
67 u_int8_t copy_mode;
68 };
69
70 static DEFINE_RWLOCK(instances_lock);
71 static atomic_t global_seq;
72
73 #define INSTANCE_BUCKETS 16
74 static struct hlist_head instance_table[INSTANCE_BUCKETS];
75 static unsigned int hash_init;
76
77 static inline u_int8_t instance_hashfn(u_int16_t group_num)
78 {
79 return ((group_num & 0xff) % INSTANCE_BUCKETS);
80 }
81
82 static struct nfulnl_instance *
83 __instance_lookup(u_int16_t group_num)
84 {
85 struct hlist_head *head;
86 struct hlist_node *pos;
87 struct nfulnl_instance *inst;
88
89 head = &instance_table[instance_hashfn(group_num)];
90 hlist_for_each_entry(inst, pos, head, hlist) {
91 if (inst->group_num == group_num)
92 return inst;
93 }
94 return NULL;
95 }
96
97 static inline void
98 instance_get(struct nfulnl_instance *inst)
99 {
100 atomic_inc(&inst->use);
101 }
102
103 static struct nfulnl_instance *
104 instance_lookup_get(u_int16_t group_num)
105 {
106 struct nfulnl_instance *inst;
107
108 read_lock_bh(&instances_lock);
109 inst = __instance_lookup(group_num);
110 if (inst)
111 instance_get(inst);
112 read_unlock_bh(&instances_lock);
113
114 return inst;
115 }
116
117 static void
118 instance_put(struct nfulnl_instance *inst)
119 {
120 if (inst && atomic_dec_and_test(&inst->use)) {
121 kfree(inst);
122 module_put(THIS_MODULE);
123 }
124 }
125
126 static void nfulnl_timer(unsigned long data);
127
128 static struct nfulnl_instance *
129 instance_create(u_int16_t group_num, int pid)
130 {
131 struct nfulnl_instance *inst;
132 int err;
133
134 write_lock_bh(&instances_lock);
135 if (__instance_lookup(group_num)) {
136 err = -EEXIST;
137 goto out_unlock;
138 }
139
140 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
141 if (!inst) {
142 err = -ENOMEM;
143 goto out_unlock;
144 }
145
146 if (!try_module_get(THIS_MODULE)) {
147 kfree(inst);
148 err = -EAGAIN;
149 goto out_unlock;
150 }
151
152 INIT_HLIST_NODE(&inst->hlist);
153 spin_lock_init(&inst->lock);
154 /* needs to be two, since we _put() after creation */
155 atomic_set(&inst->use, 2);
156
157 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
158
159 inst->peer_pid = pid;
160 inst->group_num = group_num;
161
162 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
163 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
164 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
165 inst->copy_mode = NFULNL_COPY_PACKET;
166 inst->copy_range = NFULNL_COPY_RANGE_MAX;
167
168 hlist_add_head(&inst->hlist,
169 &instance_table[instance_hashfn(group_num)]);
170
171 write_unlock_bh(&instances_lock);
172
173 return inst;
174
175 out_unlock:
176 write_unlock_bh(&instances_lock);
177 return ERR_PTR(err);
178 }
179
180 static void __nfulnl_flush(struct nfulnl_instance *inst);
181
182 static void
183 __instance_destroy(struct nfulnl_instance *inst)
184 {
185 /* first pull it out of the global list */
186 hlist_del(&inst->hlist);
187
188 /* then flush all pending packets from skb */
189
190 spin_lock_bh(&inst->lock);
191 if (inst->skb)
192 __nfulnl_flush(inst);
193 spin_unlock_bh(&inst->lock);
194
195 /* and finally put the refcount */
196 instance_put(inst);
197 }
198
199 static inline void
200 instance_destroy(struct nfulnl_instance *inst)
201 {
202 write_lock_bh(&instances_lock);
203 __instance_destroy(inst);
204 write_unlock_bh(&instances_lock);
205 }
206
207 static int
208 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
209 unsigned int range)
210 {
211 int status = 0;
212
213 spin_lock_bh(&inst->lock);
214
215 switch (mode) {
216 case NFULNL_COPY_NONE:
217 case NFULNL_COPY_META:
218 inst->copy_mode = mode;
219 inst->copy_range = 0;
220 break;
221
222 case NFULNL_COPY_PACKET:
223 inst->copy_mode = mode;
224 inst->copy_range = min_t(unsigned int,
225 range, NFULNL_COPY_RANGE_MAX);
226 break;
227
228 default:
229 status = -EINVAL;
230 break;
231 }
232
233 spin_unlock_bh(&inst->lock);
234
235 return status;
236 }
237
238 static int
239 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
240 {
241 int status;
242
243 spin_lock_bh(&inst->lock);
244 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
245 status = -ERANGE;
246 else if (nlbufsiz > 131072)
247 status = -ERANGE;
248 else {
249 inst->nlbufsiz = nlbufsiz;
250 status = 0;
251 }
252 spin_unlock_bh(&inst->lock);
253
254 return status;
255 }
256
257 static int
258 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
259 {
260 spin_lock_bh(&inst->lock);
261 inst->flushtimeout = timeout;
262 spin_unlock_bh(&inst->lock);
263
264 return 0;
265 }
266
267 static int
268 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
269 {
270 spin_lock_bh(&inst->lock);
271 inst->qthreshold = qthresh;
272 spin_unlock_bh(&inst->lock);
273
274 return 0;
275 }
276
277 static int
278 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
279 {
280 spin_lock_bh(&inst->lock);
281 inst->flags = flags;
282 spin_unlock_bh(&inst->lock);
283
284 return 0;
285 }
286
287 static struct sk_buff *
288 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
289 {
290 struct sk_buff *skb;
291 unsigned int n;
292
293 /* alloc skb which should be big enough for a whole multipart
294 * message. WARNING: has to be <= 128k due to slab restrictions */
295
296 n = max(inst_size, pkt_size);
297 skb = alloc_skb(n, GFP_ATOMIC);
298 if (!skb) {
299 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
300 inst_size);
301
302 if (n > pkt_size) {
303 /* try to allocate only as much as we need for current
304 * packet */
305
306 skb = alloc_skb(pkt_size, GFP_ATOMIC);
307 if (!skb)
308 PRINTR("nfnetlink_log: can't even alloc %u "
309 "bytes\n", pkt_size);
310 }
311 }
312
313 return skb;
314 }
315
316 static int
317 __nfulnl_send(struct nfulnl_instance *inst)
318 {
319 int status = -1;
320
321 if (inst->qlen > 1)
322 NLMSG_PUT(inst->skb, 0, 0,
323 NLMSG_DONE,
324 sizeof(struct nfgenmsg));
325
326 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
327
328 inst->qlen = 0;
329 inst->skb = NULL;
330
331 nlmsg_failure:
332 return status;
333 }
334
335 static void
336 __nfulnl_flush(struct nfulnl_instance *inst)
337 {
338 /* timer holds a reference */
339 if (del_timer(&inst->timer))
340 instance_put(inst);
341 if (inst->skb)
342 __nfulnl_send(inst);
343 }
344
345 static void
346 nfulnl_timer(unsigned long data)
347 {
348 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
349
350 spin_lock_bh(&inst->lock);
351 if (inst->skb)
352 __nfulnl_send(inst);
353 spin_unlock_bh(&inst->lock);
354 instance_put(inst);
355 }
356
357 /* This is an inline function, we don't really care about a long
358 * list of arguments */
359 static inline int
360 __build_packet_message(struct nfulnl_instance *inst,
361 const struct sk_buff *skb,
362 unsigned int data_len,
363 u_int8_t pf,
364 unsigned int hooknum,
365 const struct net_device *indev,
366 const struct net_device *outdev,
367 const struct nf_loginfo *li,
368 const char *prefix, unsigned int plen)
369 {
370 struct nfulnl_msg_packet_hdr pmsg;
371 struct nlmsghdr *nlh;
372 struct nfgenmsg *nfmsg;
373 __be32 tmp_uint;
374 sk_buff_data_t old_tail = inst->skb->tail;
375
376 nlh = NLMSG_PUT(inst->skb, 0, 0,
377 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
378 sizeof(struct nfgenmsg));
379 nfmsg = NLMSG_DATA(nlh);
380 nfmsg->nfgen_family = pf;
381 nfmsg->version = NFNETLINK_V0;
382 nfmsg->res_id = htons(inst->group_num);
383
384 pmsg.hw_protocol = skb->protocol;
385 pmsg.hook = hooknum;
386
387 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
388
389 if (prefix)
390 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
391
392 if (indev) {
393 #ifndef CONFIG_BRIDGE_NETFILTER
394 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
395 htonl(indev->ifindex));
396 #else
397 if (pf == PF_BRIDGE) {
398 /* Case 1: outdev is physical input device, we need to
399 * look for bridge group (when called from
400 * netfilter_bridge) */
401 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
402 htonl(indev->ifindex));
403 /* this is the bridge group "brX" */
404 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
405 htonl(indev->br_port->br->dev->ifindex));
406 } else {
407 /* Case 2: indev is bridge group, we need to look for
408 * physical device (when called from ipv4) */
409 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
410 htonl(indev->ifindex));
411 if (skb->nf_bridge && skb->nf_bridge->physindev)
412 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
413 htonl(skb->nf_bridge->physindev->ifindex));
414 }
415 #endif
416 }
417
418 if (outdev) {
419 tmp_uint = htonl(outdev->ifindex);
420 #ifndef CONFIG_BRIDGE_NETFILTER
421 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
422 htonl(outdev->ifindex));
423 #else
424 if (pf == PF_BRIDGE) {
425 /* Case 1: outdev is physical output device, we need to
426 * look for bridge group (when called from
427 * netfilter_bridge) */
428 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
429 htonl(outdev->ifindex));
430 /* this is the bridge group "brX" */
431 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
432 htonl(outdev->br_port->br->dev->ifindex));
433 } else {
434 /* Case 2: indev is a bridge group, we need to look
435 * for physical device (when called from ipv4) */
436 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
437 htonl(outdev->ifindex));
438 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
439 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
440 htonl(skb->nf_bridge->physoutdev->ifindex));
441 }
442 #endif
443 }
444
445 if (skb->mark)
446 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
447
448 if (indev && skb->dev) {
449 struct nfulnl_msg_packet_hw phw;
450 int len = dev_parse_header(skb, phw.hw_addr);
451 if (len > 0) {
452 phw.hw_addrlen = htons(len);
453 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
454 }
455 }
456
457 if (indev && skb_mac_header_was_set(skb)) {
458 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
459 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
460 htons(skb->dev->hard_header_len));
461 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
462 skb_mac_header(skb));
463 }
464
465 if (skb->tstamp.tv64) {
466 struct nfulnl_msg_packet_timestamp ts;
467 struct timeval tv = ktime_to_timeval(skb->tstamp);
468 ts.sec = cpu_to_be64(tv.tv_sec);
469 ts.usec = cpu_to_be64(tv.tv_usec);
470
471 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
472 }
473
474 /* UID */
475 if (skb->sk) {
476 read_lock_bh(&skb->sk->sk_callback_lock);
477 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
478 struct file *file = skb->sk->sk_socket->file;
479 __be32 uid = htonl(file->f_cred->fsuid);
480 __be32 gid = htonl(file->f_cred->fsgid);
481 /* need to unlock here since NLA_PUT may goto */
482 read_unlock_bh(&skb->sk->sk_callback_lock);
483 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
484 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
485 } else
486 read_unlock_bh(&skb->sk->sk_callback_lock);
487 }
488
489 /* local sequence number */
490 if (inst->flags & NFULNL_CFG_F_SEQ)
491 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
492
493 /* global sequence number */
494 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
495 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
496 htonl(atomic_inc_return(&global_seq)));
497
498 if (data_len) {
499 struct nlattr *nla;
500 int size = nla_attr_size(data_len);
501
502 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
503 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
504 goto nlmsg_failure;
505 }
506
507 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
508 nla->nla_type = NFULA_PAYLOAD;
509 nla->nla_len = size;
510
511 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
512 BUG();
513 }
514
515 nlh->nlmsg_len = inst->skb->tail - old_tail;
516 return 0;
517
518 nlmsg_failure:
519 nla_put_failure:
520 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
521 return -1;
522 }
523
524 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
525
526 static struct nf_loginfo default_loginfo = {
527 .type = NF_LOG_TYPE_ULOG,
528 .u = {
529 .ulog = {
530 .copy_len = 0xffff,
531 .group = 0,
532 .qthreshold = 1,
533 },
534 },
535 };
536
537 /* log handler for internal netfilter logging api */
538 void
539 nfulnl_log_packet(u_int8_t pf,
540 unsigned int hooknum,
541 const struct sk_buff *skb,
542 const struct net_device *in,
543 const struct net_device *out,
544 const struct nf_loginfo *li_user,
545 const char *prefix)
546 {
547 unsigned int size, data_len;
548 struct nfulnl_instance *inst;
549 const struct nf_loginfo *li;
550 unsigned int qthreshold;
551 unsigned int plen;
552
553 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
554 li = li_user;
555 else
556 li = &default_loginfo;
557
558 inst = instance_lookup_get(li->u.ulog.group);
559 if (!inst)
560 return;
561
562 plen = 0;
563 if (prefix)
564 plen = strlen(prefix) + 1;
565
566 /* FIXME: do we want to make the size calculation conditional based on
567 * what is actually present? way more branches and checks, but more
568 * memory efficient... */
569 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
570 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
571 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
572 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
573 #ifdef CONFIG_BRIDGE_NETFILTER
574 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
575 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
576 #endif
577 + nla_total_size(sizeof(u_int32_t)) /* mark */
578 + nla_total_size(sizeof(u_int32_t)) /* uid */
579 + nla_total_size(sizeof(u_int32_t)) /* gid */
580 + nla_total_size(plen) /* prefix */
581 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
582 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
583
584 if (in && skb_mac_header_was_set(skb)) {
585 size += nla_total_size(skb->dev->hard_header_len)
586 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
587 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
588 }
589
590 spin_lock_bh(&inst->lock);
591
592 if (inst->flags & NFULNL_CFG_F_SEQ)
593 size += nla_total_size(sizeof(u_int32_t));
594 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
595 size += nla_total_size(sizeof(u_int32_t));
596
597 qthreshold = inst->qthreshold;
598 /* per-rule qthreshold overrides per-instance */
599 if (li->u.ulog.qthreshold)
600 if (qthreshold > li->u.ulog.qthreshold)
601 qthreshold = li->u.ulog.qthreshold;
602
603
604 switch (inst->copy_mode) {
605 case NFULNL_COPY_META:
606 case NFULNL_COPY_NONE:
607 data_len = 0;
608 break;
609
610 case NFULNL_COPY_PACKET:
611 if (inst->copy_range == 0
612 || inst->copy_range > skb->len)
613 data_len = skb->len;
614 else
615 data_len = inst->copy_range;
616
617 size += nla_total_size(data_len);
618 break;
619
620 default:
621 goto unlock_and_release;
622 }
623
624 if (inst->skb &&
625 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
626 /* either the queue len is too high or we don't have
627 * enough room in the skb left. flush to userspace. */
628 __nfulnl_flush(inst);
629 }
630
631 if (!inst->skb) {
632 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
633 if (!inst->skb)
634 goto alloc_failure;
635 }
636
637 inst->qlen++;
638
639 __build_packet_message(inst, skb, data_len, pf,
640 hooknum, in, out, li, prefix, plen);
641
642 if (inst->qlen >= qthreshold)
643 __nfulnl_flush(inst);
644 /* timer_pending always called within inst->lock, so there
645 * is no chance of a race here */
646 else if (!timer_pending(&inst->timer)) {
647 instance_get(inst);
648 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
649 add_timer(&inst->timer);
650 }
651
652 unlock_and_release:
653 spin_unlock_bh(&inst->lock);
654 instance_put(inst);
655 return;
656
657 alloc_failure:
658 /* FIXME: statistics */
659 goto unlock_and_release;
660 }
661 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
662
663 static int
664 nfulnl_rcv_nl_event(struct notifier_block *this,
665 unsigned long event, void *ptr)
666 {
667 struct netlink_notify *n = ptr;
668
669 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
670 int i;
671
672 /* destroy all instances for this pid */
673 write_lock_bh(&instances_lock);
674 for (i = 0; i < INSTANCE_BUCKETS; i++) {
675 struct hlist_node *tmp, *t2;
676 struct nfulnl_instance *inst;
677 struct hlist_head *head = &instance_table[i];
678
679 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
680 if ((net_eq(n->net, &init_net)) &&
681 (n->pid == inst->peer_pid))
682 __instance_destroy(inst);
683 }
684 }
685 write_unlock_bh(&instances_lock);
686 }
687 return NOTIFY_DONE;
688 }
689
690 static struct notifier_block nfulnl_rtnl_notifier = {
691 .notifier_call = nfulnl_rcv_nl_event,
692 };
693
694 static int
695 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
696 const struct nlmsghdr *nlh,
697 const struct nlattr * const nfqa[])
698 {
699 return -ENOTSUPP;
700 }
701
702 static struct nf_logger nfulnl_logger __read_mostly = {
703 .name = "nfnetlink_log",
704 .logfn = &nfulnl_log_packet,
705 .me = THIS_MODULE,
706 };
707
708 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
709 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
710 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
711 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
712 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
713 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
714 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
715 };
716
717 static int
718 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
719 const struct nlmsghdr *nlh,
720 const struct nlattr * const nfula[])
721 {
722 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
723 u_int16_t group_num = ntohs(nfmsg->res_id);
724 struct nfulnl_instance *inst;
725 struct nfulnl_msg_config_cmd *cmd = NULL;
726 int ret = 0;
727
728 if (nfula[NFULA_CFG_CMD]) {
729 u_int8_t pf = nfmsg->nfgen_family;
730 cmd = nla_data(nfula[NFULA_CFG_CMD]);
731
732 /* Commands without queue context */
733 switch (cmd->command) {
734 case NFULNL_CFG_CMD_PF_BIND:
735 return nf_log_bind_pf(pf, &nfulnl_logger);
736 case NFULNL_CFG_CMD_PF_UNBIND:
737 nf_log_unbind_pf(pf);
738 return 0;
739 }
740 }
741
742 inst = instance_lookup_get(group_num);
743 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
744 ret = -EPERM;
745 goto out_put;
746 }
747
748 if (cmd != NULL) {
749 switch (cmd->command) {
750 case NFULNL_CFG_CMD_BIND:
751 if (inst) {
752 ret = -EBUSY;
753 goto out_put;
754 }
755
756 inst = instance_create(group_num,
757 NETLINK_CB(skb).pid);
758 if (IS_ERR(inst)) {
759 ret = PTR_ERR(inst);
760 goto out;
761 }
762 break;
763 case NFULNL_CFG_CMD_UNBIND:
764 if (!inst) {
765 ret = -ENODEV;
766 goto out;
767 }
768
769 instance_destroy(inst);
770 goto out;
771 default:
772 ret = -ENOTSUPP;
773 break;
774 }
775 }
776
777 if (nfula[NFULA_CFG_MODE]) {
778 struct nfulnl_msg_config_mode *params;
779 params = nla_data(nfula[NFULA_CFG_MODE]);
780
781 if (!inst) {
782 ret = -ENODEV;
783 goto out;
784 }
785 nfulnl_set_mode(inst, params->copy_mode,
786 ntohl(params->copy_range));
787 }
788
789 if (nfula[NFULA_CFG_TIMEOUT]) {
790 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
791
792 if (!inst) {
793 ret = -ENODEV;
794 goto out;
795 }
796 nfulnl_set_timeout(inst, ntohl(timeout));
797 }
798
799 if (nfula[NFULA_CFG_NLBUFSIZ]) {
800 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
801
802 if (!inst) {
803 ret = -ENODEV;
804 goto out;
805 }
806 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
807 }
808
809 if (nfula[NFULA_CFG_QTHRESH]) {
810 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
811
812 if (!inst) {
813 ret = -ENODEV;
814 goto out;
815 }
816 nfulnl_set_qthresh(inst, ntohl(qthresh));
817 }
818
819 if (nfula[NFULA_CFG_FLAGS]) {
820 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
821
822 if (!inst) {
823 ret = -ENODEV;
824 goto out;
825 }
826 nfulnl_set_flags(inst, ntohs(flags));
827 }
828
829 out_put:
830 instance_put(inst);
831 out:
832 return ret;
833 }
834
835 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
836 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
837 .attr_count = NFULA_MAX, },
838 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
839 .attr_count = NFULA_CFG_MAX,
840 .policy = nfula_cfg_policy },
841 };
842
843 static const struct nfnetlink_subsystem nfulnl_subsys = {
844 .name = "log",
845 .subsys_id = NFNL_SUBSYS_ULOG,
846 .cb_count = NFULNL_MSG_MAX,
847 .cb = nfulnl_cb,
848 };
849
850 #ifdef CONFIG_PROC_FS
851 struct iter_state {
852 unsigned int bucket;
853 };
854
855 static struct hlist_node *get_first(struct iter_state *st)
856 {
857 if (!st)
858 return NULL;
859
860 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
861 if (!hlist_empty(&instance_table[st->bucket]))
862 return instance_table[st->bucket].first;
863 }
864 return NULL;
865 }
866
867 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
868 {
869 h = h->next;
870 while (!h) {
871 if (++st->bucket >= INSTANCE_BUCKETS)
872 return NULL;
873
874 h = instance_table[st->bucket].first;
875 }
876 return h;
877 }
878
879 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
880 {
881 struct hlist_node *head;
882 head = get_first(st);
883
884 if (head)
885 while (pos && (head = get_next(st, head)))
886 pos--;
887 return pos ? NULL : head;
888 }
889
890 static void *seq_start(struct seq_file *seq, loff_t *pos)
891 __acquires(instances_lock)
892 {
893 read_lock_bh(&instances_lock);
894 return get_idx(seq->private, *pos);
895 }
896
897 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
898 {
899 (*pos)++;
900 return get_next(s->private, v);
901 }
902
903 static void seq_stop(struct seq_file *s, void *v)
904 __releases(instances_lock)
905 {
906 read_unlock_bh(&instances_lock);
907 }
908
909 static int seq_show(struct seq_file *s, void *v)
910 {
911 const struct nfulnl_instance *inst = v;
912
913 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
914 inst->group_num,
915 inst->peer_pid, inst->qlen,
916 inst->copy_mode, inst->copy_range,
917 inst->flushtimeout, atomic_read(&inst->use));
918 }
919
920 static const struct seq_operations nful_seq_ops = {
921 .start = seq_start,
922 .next = seq_next,
923 .stop = seq_stop,
924 .show = seq_show,
925 };
926
927 static int nful_open(struct inode *inode, struct file *file)
928 {
929 return seq_open_private(file, &nful_seq_ops,
930 sizeof(struct iter_state));
931 }
932
933 static const struct file_operations nful_file_ops = {
934 .owner = THIS_MODULE,
935 .open = nful_open,
936 .read = seq_read,
937 .llseek = seq_lseek,
938 .release = seq_release_private,
939 };
940
941 #endif /* PROC_FS */
942
943 static int __init nfnetlink_log_init(void)
944 {
945 int i, status = -ENOMEM;
946
947 for (i = 0; i < INSTANCE_BUCKETS; i++)
948 INIT_HLIST_HEAD(&instance_table[i]);
949
950 /* it's not really all that important to have a random value, so
951 * we can do this from the init function, even if there hasn't
952 * been that much entropy yet */
953 get_random_bytes(&hash_init, sizeof(hash_init));
954
955 netlink_register_notifier(&nfulnl_rtnl_notifier);
956 status = nfnetlink_subsys_register(&nfulnl_subsys);
957 if (status < 0) {
958 printk(KERN_ERR "log: failed to create netlink socket\n");
959 goto cleanup_netlink_notifier;
960 }
961
962 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
963 if (status < 0) {
964 printk(KERN_ERR "log: failed to register logger\n");
965 goto cleanup_subsys;
966 }
967
968 #ifdef CONFIG_PROC_FS
969 if (!proc_create("nfnetlink_log", 0440,
970 proc_net_netfilter, &nful_file_ops))
971 goto cleanup_logger;
972 #endif
973 return status;
974
975 #ifdef CONFIG_PROC_FS
976 cleanup_logger:
977 nf_log_unregister(&nfulnl_logger);
978 #endif
979 cleanup_subsys:
980 nfnetlink_subsys_unregister(&nfulnl_subsys);
981 cleanup_netlink_notifier:
982 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
983 return status;
984 }
985
986 static void __exit nfnetlink_log_fini(void)
987 {
988 nf_log_unregister(&nfulnl_logger);
989 #ifdef CONFIG_PROC_FS
990 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
991 #endif
992 nfnetlink_subsys_unregister(&nfulnl_subsys);
993 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
994 }
995
996 MODULE_DESCRIPTION("netfilter userspace logging");
997 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
998 MODULE_LICENSE("GPL");
999 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1000
1001 module_init(nfnetlink_log_init);
1002 module_exit(nfnetlink_log_fini);
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