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Merge branch 'lpc32xx/core' of git://git.antcom.de/linux-2.6 into next/soc
[mirror_ubuntu-jammy-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 <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 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
331 NLMSG_DONE,
332 sizeof(struct nfgenmsg),
333 0);
334 if (!nlh)
335 goto out;
336 }
337 status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid,
338 MSG_DONTWAIT);
339
340 inst->qlen = 0;
341 inst->skb = NULL;
342 out:
343 return status;
344 }
345
346 static void
347 __nfulnl_flush(struct nfulnl_instance *inst)
348 {
349 /* timer holds a reference */
350 if (del_timer(&inst->timer))
351 instance_put(inst);
352 if (inst->skb)
353 __nfulnl_send(inst);
354 }
355
356 static void
357 nfulnl_timer(unsigned long data)
358 {
359 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
360
361 spin_lock_bh(&inst->lock);
362 if (inst->skb)
363 __nfulnl_send(inst);
364 spin_unlock_bh(&inst->lock);
365 instance_put(inst);
366 }
367
368 /* This is an inline function, we don't really care about a long
369 * list of arguments */
370 static inline int
371 __build_packet_message(struct nfulnl_instance *inst,
372 const struct sk_buff *skb,
373 unsigned int data_len,
374 u_int8_t pf,
375 unsigned int hooknum,
376 const struct net_device *indev,
377 const struct net_device *outdev,
378 const char *prefix, unsigned int plen)
379 {
380 struct nfulnl_msg_packet_hdr pmsg;
381 struct nlmsghdr *nlh;
382 struct nfgenmsg *nfmsg;
383 sk_buff_data_t old_tail = inst->skb->tail;
384 struct sock *sk;
385
386 nlh = nlmsg_put(inst->skb, 0, 0,
387 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
388 sizeof(struct nfgenmsg), 0);
389 if (!nlh)
390 return -1;
391 nfmsg = nlmsg_data(nlh);
392 nfmsg->nfgen_family = pf;
393 nfmsg->version = NFNETLINK_V0;
394 nfmsg->res_id = htons(inst->group_num);
395
396 pmsg.hw_protocol = skb->protocol;
397 pmsg.hook = hooknum;
398
399 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
400 goto nla_put_failure;
401
402 if (prefix &&
403 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
404 goto nla_put_failure;
405
406 if (indev) {
407 #ifndef CONFIG_BRIDGE_NETFILTER
408 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
409 htonl(indev->ifindex)))
410 goto nla_put_failure;
411 #else
412 if (pf == PF_BRIDGE) {
413 /* Case 1: outdev is physical input device, we need to
414 * look for bridge group (when called from
415 * netfilter_bridge) */
416 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
417 htonl(indev->ifindex)) ||
418 /* this is the bridge group "brX" */
419 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
420 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
421 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
422 goto nla_put_failure;
423 } else {
424 /* Case 2: indev is bridge group, we need to look for
425 * physical device (when called from ipv4) */
426 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
427 htonl(indev->ifindex)))
428 goto nla_put_failure;
429 if (skb->nf_bridge && skb->nf_bridge->physindev &&
430 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
431 htonl(skb->nf_bridge->physindev->ifindex)))
432 goto nla_put_failure;
433 }
434 #endif
435 }
436
437 if (outdev) {
438 #ifndef CONFIG_BRIDGE_NETFILTER
439 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
440 htonl(outdev->ifindex)))
441 goto nla_put_failure;
442 #else
443 if (pf == PF_BRIDGE) {
444 /* Case 1: outdev is physical output device, we need to
445 * look for bridge group (when called from
446 * netfilter_bridge) */
447 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
448 htonl(outdev->ifindex)) ||
449 /* this is the bridge group "brX" */
450 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
451 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
452 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
453 goto nla_put_failure;
454 } else {
455 /* Case 2: indev is a bridge group, we need to look
456 * for physical device (when called from ipv4) */
457 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
458 htonl(outdev->ifindex)))
459 goto nla_put_failure;
460 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
461 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
462 htonl(skb->nf_bridge->physoutdev->ifindex)))
463 goto nla_put_failure;
464 }
465 #endif
466 }
467
468 if (skb->mark &&
469 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
470 goto nla_put_failure;
471
472 if (indev && skb->dev &&
473 skb->mac_header != skb->network_header) {
474 struct nfulnl_msg_packet_hw phw;
475 int len = dev_parse_header(skb, phw.hw_addr);
476 if (len > 0) {
477 phw.hw_addrlen = htons(len);
478 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
479 goto nla_put_failure;
480 }
481 }
482
483 if (indev && skb_mac_header_was_set(skb)) {
484 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
485 nla_put_be16(inst->skb, NFULA_HWLEN,
486 htons(skb->dev->hard_header_len)) ||
487 nla_put(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
488 skb_mac_header(skb)))
489 goto nla_put_failure;
490 }
491
492 if (skb->tstamp.tv64) {
493 struct nfulnl_msg_packet_timestamp ts;
494 struct timeval tv = ktime_to_timeval(skb->tstamp);
495 ts.sec = cpu_to_be64(tv.tv_sec);
496 ts.usec = cpu_to_be64(tv.tv_usec);
497
498 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
499 goto nla_put_failure;
500 }
501
502 /* UID */
503 sk = skb->sk;
504 if (sk && sk->sk_state != TCP_TIME_WAIT) {
505 read_lock_bh(&sk->sk_callback_lock);
506 if (sk->sk_socket && sk->sk_socket->file) {
507 struct file *file = sk->sk_socket->file;
508 __be32 uid = htonl(file->f_cred->fsuid);
509 __be32 gid = htonl(file->f_cred->fsgid);
510 read_unlock_bh(&sk->sk_callback_lock);
511 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
512 nla_put_be32(inst->skb, NFULA_GID, gid))
513 goto nla_put_failure;
514 } else
515 read_unlock_bh(&sk->sk_callback_lock);
516 }
517
518 /* local sequence number */
519 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
520 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
521 goto nla_put_failure;
522
523 /* global sequence number */
524 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
525 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
526 htonl(atomic_inc_return(&global_seq))))
527 goto nla_put_failure;
528
529 if (data_len) {
530 struct nlattr *nla;
531 int size = nla_attr_size(data_len);
532
533 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
534 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
535 return -1;
536 }
537
538 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
539 nla->nla_type = NFULA_PAYLOAD;
540 nla->nla_len = size;
541
542 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
543 BUG();
544 }
545
546 nlh->nlmsg_len = inst->skb->tail - old_tail;
547 return 0;
548
549 nla_put_failure:
550 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
551 return -1;
552 }
553
554 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
555
556 static struct nf_loginfo default_loginfo = {
557 .type = NF_LOG_TYPE_ULOG,
558 .u = {
559 .ulog = {
560 .copy_len = 0xffff,
561 .group = 0,
562 .qthreshold = 1,
563 },
564 },
565 };
566
567 /* log handler for internal netfilter logging api */
568 void
569 nfulnl_log_packet(u_int8_t pf,
570 unsigned int hooknum,
571 const struct sk_buff *skb,
572 const struct net_device *in,
573 const struct net_device *out,
574 const struct nf_loginfo *li_user,
575 const char *prefix)
576 {
577 unsigned int size, data_len;
578 struct nfulnl_instance *inst;
579 const struct nf_loginfo *li;
580 unsigned int qthreshold;
581 unsigned int plen;
582
583 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
584 li = li_user;
585 else
586 li = &default_loginfo;
587
588 inst = instance_lookup_get(li->u.ulog.group);
589 if (!inst)
590 return;
591
592 plen = 0;
593 if (prefix)
594 plen = strlen(prefix) + 1;
595
596 /* FIXME: do we want to make the size calculation conditional based on
597 * what is actually present? way more branches and checks, but more
598 * memory efficient... */
599 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
600 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
601 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
602 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
603 #ifdef CONFIG_BRIDGE_NETFILTER
604 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
605 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
606 #endif
607 + nla_total_size(sizeof(u_int32_t)) /* mark */
608 + nla_total_size(sizeof(u_int32_t)) /* uid */
609 + nla_total_size(sizeof(u_int32_t)) /* gid */
610 + nla_total_size(plen) /* prefix */
611 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
612 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
613
614 if (in && skb_mac_header_was_set(skb)) {
615 size += nla_total_size(skb->dev->hard_header_len)
616 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
617 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
618 }
619
620 spin_lock_bh(&inst->lock);
621
622 if (inst->flags & NFULNL_CFG_F_SEQ)
623 size += nla_total_size(sizeof(u_int32_t));
624 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
625 size += nla_total_size(sizeof(u_int32_t));
626
627 qthreshold = inst->qthreshold;
628 /* per-rule qthreshold overrides per-instance */
629 if (li->u.ulog.qthreshold)
630 if (qthreshold > li->u.ulog.qthreshold)
631 qthreshold = li->u.ulog.qthreshold;
632
633
634 switch (inst->copy_mode) {
635 case NFULNL_COPY_META:
636 case NFULNL_COPY_NONE:
637 data_len = 0;
638 break;
639
640 case NFULNL_COPY_PACKET:
641 if (inst->copy_range == 0
642 || inst->copy_range > skb->len)
643 data_len = skb->len;
644 else
645 data_len = inst->copy_range;
646
647 size += nla_total_size(data_len);
648 break;
649
650 case NFULNL_COPY_DISABLED:
651 default:
652 goto unlock_and_release;
653 }
654
655 if (inst->skb &&
656 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
657 /* either the queue len is too high or we don't have
658 * enough room in the skb left. flush to userspace. */
659 __nfulnl_flush(inst);
660 }
661
662 if (!inst->skb) {
663 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
664 if (!inst->skb)
665 goto alloc_failure;
666 }
667
668 inst->qlen++;
669
670 __build_packet_message(inst, skb, data_len, pf,
671 hooknum, in, out, prefix, plen);
672
673 if (inst->qlen >= qthreshold)
674 __nfulnl_flush(inst);
675 /* timer_pending always called within inst->lock, so there
676 * is no chance of a race here */
677 else if (!timer_pending(&inst->timer)) {
678 instance_get(inst);
679 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
680 add_timer(&inst->timer);
681 }
682
683 unlock_and_release:
684 spin_unlock_bh(&inst->lock);
685 instance_put(inst);
686 return;
687
688 alloc_failure:
689 /* FIXME: statistics */
690 goto unlock_and_release;
691 }
692 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
693
694 static int
695 nfulnl_rcv_nl_event(struct notifier_block *this,
696 unsigned long event, void *ptr)
697 {
698 struct netlink_notify *n = ptr;
699
700 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
701 int i;
702
703 /* destroy all instances for this pid */
704 spin_lock_bh(&instances_lock);
705 for (i = 0; i < INSTANCE_BUCKETS; i++) {
706 struct hlist_node *tmp, *t2;
707 struct nfulnl_instance *inst;
708 struct hlist_head *head = &instance_table[i];
709
710 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
711 if ((net_eq(n->net, &init_net)) &&
712 (n->pid == inst->peer_pid))
713 __instance_destroy(inst);
714 }
715 }
716 spin_unlock_bh(&instances_lock);
717 }
718 return NOTIFY_DONE;
719 }
720
721 static struct notifier_block nfulnl_rtnl_notifier = {
722 .notifier_call = nfulnl_rcv_nl_event,
723 };
724
725 static int
726 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
727 const struct nlmsghdr *nlh,
728 const struct nlattr * const nfqa[])
729 {
730 return -ENOTSUPP;
731 }
732
733 static struct nf_logger nfulnl_logger __read_mostly = {
734 .name = "nfnetlink_log",
735 .logfn = &nfulnl_log_packet,
736 .me = THIS_MODULE,
737 };
738
739 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
740 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
741 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
742 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
743 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
744 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
745 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
746 };
747
748 static int
749 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
750 const struct nlmsghdr *nlh,
751 const struct nlattr * const nfula[])
752 {
753 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
754 u_int16_t group_num = ntohs(nfmsg->res_id);
755 struct nfulnl_instance *inst;
756 struct nfulnl_msg_config_cmd *cmd = NULL;
757 int ret = 0;
758
759 if (nfula[NFULA_CFG_CMD]) {
760 u_int8_t pf = nfmsg->nfgen_family;
761 cmd = nla_data(nfula[NFULA_CFG_CMD]);
762
763 /* Commands without queue context */
764 switch (cmd->command) {
765 case NFULNL_CFG_CMD_PF_BIND:
766 return nf_log_bind_pf(pf, &nfulnl_logger);
767 case NFULNL_CFG_CMD_PF_UNBIND:
768 nf_log_unbind_pf(pf);
769 return 0;
770 }
771 }
772
773 inst = instance_lookup_get(group_num);
774 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
775 ret = -EPERM;
776 goto out_put;
777 }
778
779 if (cmd != NULL) {
780 switch (cmd->command) {
781 case NFULNL_CFG_CMD_BIND:
782 if (inst) {
783 ret = -EBUSY;
784 goto out_put;
785 }
786
787 inst = instance_create(group_num,
788 NETLINK_CB(skb).pid);
789 if (IS_ERR(inst)) {
790 ret = PTR_ERR(inst);
791 goto out;
792 }
793 break;
794 case NFULNL_CFG_CMD_UNBIND:
795 if (!inst) {
796 ret = -ENODEV;
797 goto out;
798 }
799
800 instance_destroy(inst);
801 goto out_put;
802 default:
803 ret = -ENOTSUPP;
804 break;
805 }
806 }
807
808 if (nfula[NFULA_CFG_MODE]) {
809 struct nfulnl_msg_config_mode *params;
810 params = nla_data(nfula[NFULA_CFG_MODE]);
811
812 if (!inst) {
813 ret = -ENODEV;
814 goto out;
815 }
816 nfulnl_set_mode(inst, params->copy_mode,
817 ntohl(params->copy_range));
818 }
819
820 if (nfula[NFULA_CFG_TIMEOUT]) {
821 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
822
823 if (!inst) {
824 ret = -ENODEV;
825 goto out;
826 }
827 nfulnl_set_timeout(inst, ntohl(timeout));
828 }
829
830 if (nfula[NFULA_CFG_NLBUFSIZ]) {
831 __be32 nlbufsiz = nla_get_be32(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 = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
842
843 if (!inst) {
844 ret = -ENODEV;
845 goto out;
846 }
847 nfulnl_set_qthresh(inst, ntohl(qthresh));
848 }
849
850 if (nfula[NFULA_CFG_FLAGS]) {
851 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
852
853 if (!inst) {
854 ret = -ENODEV;
855 goto out;
856 }
857 nfulnl_set_flags(inst, ntohs(flags));
858 }
859
860 out_put:
861 instance_put(inst);
862 out:
863 return ret;
864 }
865
866 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
867 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
868 .attr_count = NFULA_MAX, },
869 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
870 .attr_count = NFULA_CFG_MAX,
871 .policy = nfula_cfg_policy },
872 };
873
874 static const struct nfnetlink_subsystem nfulnl_subsys = {
875 .name = "log",
876 .subsys_id = NFNL_SUBSYS_ULOG,
877 .cb_count = NFULNL_MSG_MAX,
878 .cb = nfulnl_cb,
879 };
880
881 #ifdef CONFIG_PROC_FS
882 struct iter_state {
883 unsigned int bucket;
884 };
885
886 static struct hlist_node *get_first(struct iter_state *st)
887 {
888 if (!st)
889 return NULL;
890
891 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
892 if (!hlist_empty(&instance_table[st->bucket]))
893 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
894 }
895 return NULL;
896 }
897
898 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
899 {
900 h = rcu_dereference_bh(hlist_next_rcu(h));
901 while (!h) {
902 if (++st->bucket >= INSTANCE_BUCKETS)
903 return NULL;
904
905 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
906 }
907 return h;
908 }
909
910 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
911 {
912 struct hlist_node *head;
913 head = get_first(st);
914
915 if (head)
916 while (pos && (head = get_next(st, head)))
917 pos--;
918 return pos ? NULL : head;
919 }
920
921 static void *seq_start(struct seq_file *seq, loff_t *pos)
922 __acquires(rcu_bh)
923 {
924 rcu_read_lock_bh();
925 return get_idx(seq->private, *pos);
926 }
927
928 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
929 {
930 (*pos)++;
931 return get_next(s->private, v);
932 }
933
934 static void seq_stop(struct seq_file *s, void *v)
935 __releases(rcu_bh)
936 {
937 rcu_read_unlock_bh();
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
978 for (i = 0; i < INSTANCE_BUCKETS; i++)
979 INIT_HLIST_HEAD(&instance_table[i]);
980
981 /* it's not really all that important to have a random value, so
982 * we can do this from the init function, even if there hasn't
983 * been that much entropy yet */
984 get_random_bytes(&hash_init, sizeof(hash_init));
985
986 netlink_register_notifier(&nfulnl_rtnl_notifier);
987 status = nfnetlink_subsys_register(&nfulnl_subsys);
988 if (status < 0) {
989 printk(KERN_ERR "log: failed to create netlink socket\n");
990 goto cleanup_netlink_notifier;
991 }
992
993 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
994 if (status < 0) {
995 printk(KERN_ERR "log: failed to register logger\n");
996 goto cleanup_subsys;
997 }
998
999 #ifdef CONFIG_PROC_FS
1000 if (!proc_create("nfnetlink_log", 0440,
1001 proc_net_netfilter, &nful_file_ops)) {
1002 status = -ENOMEM;
1003 goto cleanup_logger;
1004 }
1005 #endif
1006 return status;
1007
1008 #ifdef CONFIG_PROC_FS
1009 cleanup_logger:
1010 nf_log_unregister(&nfulnl_logger);
1011 #endif
1012 cleanup_subsys:
1013 nfnetlink_subsys_unregister(&nfulnl_subsys);
1014 cleanup_netlink_notifier:
1015 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1016 return status;
1017 }
1018
1019 static void __exit nfnetlink_log_fini(void)
1020 {
1021 nf_log_unregister(&nfulnl_logger);
1022 #ifdef CONFIG_PROC_FS
1023 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1024 #endif
1025 nfnetlink_subsys_unregister(&nfulnl_subsys);
1026 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1027 }
1028
1029 MODULE_DESCRIPTION("netfilter userspace logging");
1030 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1031 MODULE_LICENSE("GPL");
1032 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1033
1034 module_init(nfnetlink_log_init);
1035 module_exit(nfnetlink_log_fini);
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