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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blob962e9792e3179997db98a448a76fc909432d841f
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 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
7 *
8 * Based on the old ipv4-only ipt_ULOG.c:
9 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15 #include <linux/module.h>
16 #include <linux/skbuff.h>
17 #include <linux/if_arp.h>
18 #include <linux/init.h>
19 #include <linux/ip.h>
20 #include <linux/ipv6.h>
21 #include <linux/netdevice.h>
22 #include <linux/netfilter.h>
23 #include <net/netlink.h>
24 #include <linux/netfilter/nfnetlink.h>
25 #include <linux/netfilter/nfnetlink_log.h>
26 #include <linux/spinlock.h>
27 #include <linux/sysctl.h>
28 #include <linux/proc_fs.h>
29 #include <linux/security.h>
30 #include <linux/list.h>
31 #include <linux/jhash.h>
32 #include <linux/random.h>
33 #include <linux/slab.h>
34 #include <net/sock.h>
35 #include <net/netfilter/nf_log.h>
36 #include <net/netns/generic.h>
37 #include <net/netfilter/nfnetlink_log.h>
38
39 #include <linux/atomic.h>
40
41 #ifdef CONFIG_BRIDGE_NETFILTER
42 #include "../bridge/br_private.h"
43 #endif
44
45 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
46 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
47 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
48 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
49
50 #define PRINTR(x, args...) do { if (net_ratelimit()) \
51 printk(x, ## args); } while (0);
52
53 struct nfulnl_instance {
54 struct hlist_node hlist; /* global list of instances */
55 spinlock_t lock;
56 atomic_t use; /* use count */
57
58 unsigned int qlen; /* number of nlmsgs in skb */
59 struct sk_buff *skb; /* pre-allocatd skb */
60 struct timer_list timer;
61 struct net *net;
62 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
63 int peer_portid; /* PORTID 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 struct rcu_head rcu;
75 };
76
77 #define INSTANCE_BUCKETS 16
78 static unsigned int hash_init;
79
80 static int nfnl_log_net_id __read_mostly;
81
82 struct nfnl_log_net {
83 spinlock_t instances_lock;
84 struct hlist_head instance_table[INSTANCE_BUCKETS];
85 atomic_t global_seq;
86 };
87
88 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
89 {
90 return net_generic(net, nfnl_log_net_id);
91 }
92
93 static inline u_int8_t instance_hashfn(u_int16_t group_num)
94 {
95 return ((group_num & 0xff) % INSTANCE_BUCKETS);
96 }
97
98 static struct nfulnl_instance *
99 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
100 {
101 struct hlist_head *head;
102 struct nfulnl_instance *inst;
103
104 head = &log->instance_table[instance_hashfn(group_num)];
105 hlist_for_each_entry_rcu(inst, head, hlist) {
106 if (inst->group_num == group_num)
107 return inst;
108 }
109 return NULL;
110 }
111
112 static inline void
113 instance_get(struct nfulnl_instance *inst)
114 {
115 atomic_inc(&inst->use);
116 }
117
118 static struct nfulnl_instance *
119 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
120 {
121 struct nfulnl_instance *inst;
122
123 rcu_read_lock_bh();
124 inst = __instance_lookup(log, group_num);
125 if (inst && !atomic_inc_not_zero(&inst->use))
126 inst = NULL;
127 rcu_read_unlock_bh();
128
129 return inst;
130 }
131
132 static void nfulnl_instance_free_rcu(struct rcu_head *head)
133 {
134 struct nfulnl_instance *inst =
135 container_of(head, struct nfulnl_instance, rcu);
136
137 put_net(inst->net);
138 kfree(inst);
139 module_put(THIS_MODULE);
140 }
141
142 static void
143 instance_put(struct nfulnl_instance *inst)
144 {
145 if (inst && atomic_dec_and_test(&inst->use))
146 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
147 }
148
149 static void nfulnl_timer(unsigned long data);
150
151 static struct nfulnl_instance *
152 instance_create(struct net *net, u_int16_t group_num,
153 int portid, struct user_namespace *user_ns)
154 {
155 struct nfulnl_instance *inst;
156 struct nfnl_log_net *log = nfnl_log_pernet(net);
157 int err;
158
159 spin_lock_bh(&log->instances_lock);
160 if (__instance_lookup(log, group_num)) {
161 err = -EEXIST;
162 goto out_unlock;
163 }
164
165 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
166 if (!inst) {
167 err = -ENOMEM;
168 goto out_unlock;
169 }
170
171 if (!try_module_get(THIS_MODULE)) {
172 kfree(inst);
173 err = -EAGAIN;
174 goto out_unlock;
175 }
176
177 INIT_HLIST_NODE(&inst->hlist);
178 spin_lock_init(&inst->lock);
179 /* needs to be two, since we _put() after creation */
180 atomic_set(&inst->use, 2);
181
182 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
183
184 inst->net = get_net(net);
185 inst->peer_user_ns = user_ns;
186 inst->peer_portid = portid;
187 inst->group_num = group_num;
188
189 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
190 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
191 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
192 inst->copy_mode = NFULNL_COPY_PACKET;
193 inst->copy_range = NFULNL_COPY_RANGE_MAX;
194
195 hlist_add_head_rcu(&inst->hlist,
196 &log->instance_table[instance_hashfn(group_num)]);
197
198
199 spin_unlock_bh(&log->instances_lock);
200
201 return inst;
202
203 out_unlock:
204 spin_unlock_bh(&log->instances_lock);
205 return ERR_PTR(err);
206 }
207
208 static void __nfulnl_flush(struct nfulnl_instance *inst);
209
210 /* called with BH disabled */
211 static void
212 __instance_destroy(struct nfulnl_instance *inst)
213 {
214 /* first pull it out of the global list */
215 hlist_del_rcu(&inst->hlist);
216
217 /* then flush all pending packets from skb */
218
219 spin_lock(&inst->lock);
220
221 /* lockless readers wont be able to use us */
222 inst->copy_mode = NFULNL_COPY_DISABLED;
223
224 if (inst->skb)
225 __nfulnl_flush(inst);
226 spin_unlock(&inst->lock);
227
228 /* and finally put the refcount */
229 instance_put(inst);
230 }
231
232 static inline void
233 instance_destroy(struct nfnl_log_net *log,
234 struct nfulnl_instance *inst)
235 {
236 spin_lock_bh(&log->instances_lock);
237 __instance_destroy(inst);
238 spin_unlock_bh(&log->instances_lock);
239 }
240
241 static int
242 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
243 unsigned int range)
244 {
245 int status = 0;
246
247 spin_lock_bh(&inst->lock);
248
249 switch (mode) {
250 case NFULNL_COPY_NONE:
251 case NFULNL_COPY_META:
252 inst->copy_mode = mode;
253 inst->copy_range = 0;
254 break;
255
256 case NFULNL_COPY_PACKET:
257 inst->copy_mode = mode;
258 inst->copy_range = min_t(unsigned int,
259 range, NFULNL_COPY_RANGE_MAX);
260 break;
261
262 default:
263 status = -EINVAL;
264 break;
265 }
266
267 spin_unlock_bh(&inst->lock);
268
269 return status;
270 }
271
272 static int
273 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
274 {
275 int status;
276
277 spin_lock_bh(&inst->lock);
278 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
279 status = -ERANGE;
280 else if (nlbufsiz > 131072)
281 status = -ERANGE;
282 else {
283 inst->nlbufsiz = nlbufsiz;
284 status = 0;
285 }
286 spin_unlock_bh(&inst->lock);
287
288 return status;
289 }
290
291 static int
292 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
293 {
294 spin_lock_bh(&inst->lock);
295 inst->flushtimeout = timeout;
296 spin_unlock_bh(&inst->lock);
297
298 return 0;
299 }
300
301 static int
302 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
303 {
304 spin_lock_bh(&inst->lock);
305 inst->qthreshold = qthresh;
306 spin_unlock_bh(&inst->lock);
307
308 return 0;
309 }
310
311 static int
312 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
313 {
314 spin_lock_bh(&inst->lock);
315 inst->flags = flags;
316 spin_unlock_bh(&inst->lock);
317
318 return 0;
319 }
320
321 static struct sk_buff *
322 nfulnl_alloc_skb(u32 peer_portid, unsigned int inst_size, unsigned int pkt_size)
323 {
324 struct sk_buff *skb;
325 unsigned int n;
326
327 /* alloc skb which should be big enough for a whole multipart
328 * message. WARNING: has to be <= 128k due to slab restrictions */
329
330 n = max(inst_size, pkt_size);
331 skb = nfnetlink_alloc_skb(&init_net, n, peer_portid, GFP_ATOMIC);
332 if (!skb) {
333 if (n > pkt_size) {
334 /* try to allocate only as much as we need for current
335 * packet */
336
337 skb = nfnetlink_alloc_skb(&init_net, pkt_size,
338 peer_portid, GFP_ATOMIC);
339 if (!skb)
340 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
341 pkt_size);
342 }
343 }
344
345 return skb;
346 }
347
348 static int
349 __nfulnl_send(struct nfulnl_instance *inst)
350 {
351 int status = -1;
352
353 if (inst->qlen > 1) {
354 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
355 NLMSG_DONE,
356 sizeof(struct nfgenmsg),
357 0);
358 if (!nlh)
359 goto out;
360 }
361 status = nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
362 MSG_DONTWAIT);
363
364 inst->qlen = 0;
365 inst->skb = NULL;
366 out:
367 return status;
368 }
369
370 static void
371 __nfulnl_flush(struct nfulnl_instance *inst)
372 {
373 /* timer holds a reference */
374 if (del_timer(&inst->timer))
375 instance_put(inst);
376 if (inst->skb)
377 __nfulnl_send(inst);
378 }
379
380 static void
381 nfulnl_timer(unsigned long data)
382 {
383 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
384
385 spin_lock_bh(&inst->lock);
386 if (inst->skb)
387 __nfulnl_send(inst);
388 spin_unlock_bh(&inst->lock);
389 instance_put(inst);
390 }
391
392 /* This is an inline function, we don't really care about a long
393 * list of arguments */
394 static inline int
395 __build_packet_message(struct nfnl_log_net *log,
396 struct nfulnl_instance *inst,
397 const struct sk_buff *skb,
398 unsigned int data_len,
399 u_int8_t pf,
400 unsigned int hooknum,
401 const struct net_device *indev,
402 const struct net_device *outdev,
403 const char *prefix, unsigned int plen)
404 {
405 struct nfulnl_msg_packet_hdr pmsg;
406 struct nlmsghdr *nlh;
407 struct nfgenmsg *nfmsg;
408 sk_buff_data_t old_tail = inst->skb->tail;
409 struct sock *sk;
410 const unsigned char *hwhdrp;
411
412 nlh = nlmsg_put(inst->skb, 0, 0,
413 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
414 sizeof(struct nfgenmsg), 0);
415 if (!nlh)
416 return -1;
417 nfmsg = nlmsg_data(nlh);
418 nfmsg->nfgen_family = pf;
419 nfmsg->version = NFNETLINK_V0;
420 nfmsg->res_id = htons(inst->group_num);
421
422 pmsg.hw_protocol = skb->protocol;
423 pmsg.hook = hooknum;
424
425 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
426 goto nla_put_failure;
427
428 if (prefix &&
429 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
430 goto nla_put_failure;
431
432 if (indev) {
433 #ifndef CONFIG_BRIDGE_NETFILTER
434 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
435 htonl(indev->ifindex)))
436 goto nla_put_failure;
437 #else
438 if (pf == PF_BRIDGE) {
439 /* Case 1: outdev is physical input device, we need to
440 * look for bridge group (when called from
441 * netfilter_bridge) */
442 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
443 htonl(indev->ifindex)) ||
444 /* this is the bridge group "brX" */
445 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
446 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
447 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
448 goto nla_put_failure;
449 } else {
450 /* Case 2: indev is bridge group, we need to look for
451 * physical device (when called from ipv4) */
452 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
453 htonl(indev->ifindex)))
454 goto nla_put_failure;
455 if (skb->nf_bridge && skb->nf_bridge->physindev &&
456 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
457 htonl(skb->nf_bridge->physindev->ifindex)))
458 goto nla_put_failure;
459 }
460 #endif
461 }
462
463 if (outdev) {
464 #ifndef CONFIG_BRIDGE_NETFILTER
465 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
466 htonl(outdev->ifindex)))
467 goto nla_put_failure;
468 #else
469 if (pf == PF_BRIDGE) {
470 /* Case 1: outdev is physical output device, we need to
471 * look for bridge group (when called from
472 * netfilter_bridge) */
473 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
474 htonl(outdev->ifindex)) ||
475 /* this is the bridge group "brX" */
476 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
477 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
478 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
479 goto nla_put_failure;
480 } else {
481 /* Case 2: indev is a bridge group, we need to look
482 * for physical device (when called from ipv4) */
483 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
484 htonl(outdev->ifindex)))
485 goto nla_put_failure;
486 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
487 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
488 htonl(skb->nf_bridge->physoutdev->ifindex)))
489 goto nla_put_failure;
490 }
491 #endif
492 }
493
494 if (skb->mark &&
495 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
496 goto nla_put_failure;
497
498 if (indev && skb->dev &&
499 skb->mac_header != skb->network_header) {
500 struct nfulnl_msg_packet_hw phw;
501 int len = dev_parse_header(skb, phw.hw_addr);
502 if (len > 0) {
503 phw.hw_addrlen = htons(len);
504 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
505 goto nla_put_failure;
506 }
507 }
508
509 if (indev && skb_mac_header_was_set(skb)) {
510 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
511 nla_put_be16(inst->skb, NFULA_HWLEN,
512 htons(skb->dev->hard_header_len)))
513 goto nla_put_failure;
514
515 hwhdrp = skb_mac_header(skb);
516
517 if (skb->dev->type == ARPHRD_SIT)
518 hwhdrp -= ETH_HLEN;
519
520 if (hwhdrp >= skb->head &&
521 nla_put(inst->skb, NFULA_HWHEADER,
522 skb->dev->hard_header_len, hwhdrp))
523 goto nla_put_failure;
524 }
525
526 if (skb->tstamp.tv64) {
527 struct nfulnl_msg_packet_timestamp ts;
528 struct timeval tv = ktime_to_timeval(skb->tstamp);
529 ts.sec = cpu_to_be64(tv.tv_sec);
530 ts.usec = cpu_to_be64(tv.tv_usec);
531
532 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
533 goto nla_put_failure;
534 }
535
536 /* UID */
537 sk = skb->sk;
538 if (sk && sk->sk_state != TCP_TIME_WAIT) {
539 read_lock_bh(&sk->sk_callback_lock);
540 if (sk->sk_socket && sk->sk_socket->file) {
541 struct file *file = sk->sk_socket->file;
542 const struct cred *cred = file->f_cred;
543 struct user_namespace *user_ns = inst->peer_user_ns;
544 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
545 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
546 read_unlock_bh(&sk->sk_callback_lock);
547 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
548 nla_put_be32(inst->skb, NFULA_GID, gid))
549 goto nla_put_failure;
550 } else
551 read_unlock_bh(&sk->sk_callback_lock);
552 }
553
554 /* local sequence number */
555 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
556 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
557 goto nla_put_failure;
558
559 /* global sequence number */
560 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
561 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
562 htonl(atomic_inc_return(&log->global_seq))))
563 goto nla_put_failure;
564
565 if (data_len) {
566 struct nlattr *nla;
567 int size = nla_attr_size(data_len);
568
569 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
570 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
571 return -1;
572 }
573
574 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
575 nla->nla_type = NFULA_PAYLOAD;
576 nla->nla_len = size;
577
578 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
579 BUG();
580 }
581
582 nlh->nlmsg_len = inst->skb->tail - old_tail;
583 return 0;
584
585 nla_put_failure:
586 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
587 return -1;
588 }
589
590 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
591
592 static struct nf_loginfo default_loginfo = {
593 .type = NF_LOG_TYPE_ULOG,
594 .u = {
595 .ulog = {
596 .copy_len = 0xffff,
597 .group = 0,
598 .qthreshold = 1,
599 },
600 },
601 };
602
603 /* log handler for internal netfilter logging api */
604 void
605 nfulnl_log_packet(struct net *net,
606 u_int8_t pf,
607 unsigned int hooknum,
608 const struct sk_buff *skb,
609 const struct net_device *in,
610 const struct net_device *out,
611 const struct nf_loginfo *li_user,
612 const char *prefix)
613 {
614 unsigned int size, data_len;
615 struct nfulnl_instance *inst;
616 const struct nf_loginfo *li;
617 unsigned int qthreshold;
618 unsigned int plen;
619 struct nfnl_log_net *log = nfnl_log_pernet(net);
620
621 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
622 li = li_user;
623 else
624 li = &default_loginfo;
625
626 inst = instance_lookup_get(log, li->u.ulog.group);
627 if (!inst)
628 return;
629
630 plen = 0;
631 if (prefix)
632 plen = strlen(prefix) + 1;
633
634 /* FIXME: do we want to make the size calculation conditional based on
635 * what is actually present? way more branches and checks, but more
636 * memory efficient... */
637 size = nlmsg_total_size(sizeof(struct nfgenmsg))
638 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
639 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
640 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
641 #ifdef CONFIG_BRIDGE_NETFILTER
642 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
643 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
644 #endif
645 + nla_total_size(sizeof(u_int32_t)) /* mark */
646 + nla_total_size(sizeof(u_int32_t)) /* uid */
647 + nla_total_size(sizeof(u_int32_t)) /* gid */
648 + nla_total_size(plen) /* prefix */
649 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
650 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
651
652 if (in && skb_mac_header_was_set(skb)) {
653 size += nla_total_size(skb->dev->hard_header_len)
654 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
655 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
656 }
657
658 spin_lock_bh(&inst->lock);
659
660 if (inst->flags & NFULNL_CFG_F_SEQ)
661 size += nla_total_size(sizeof(u_int32_t));
662 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
663 size += nla_total_size(sizeof(u_int32_t));
664
665 qthreshold = inst->qthreshold;
666 /* per-rule qthreshold overrides per-instance */
667 if (li->u.ulog.qthreshold)
668 if (qthreshold > li->u.ulog.qthreshold)
669 qthreshold = li->u.ulog.qthreshold;
670
671
672 switch (inst->copy_mode) {
673 case NFULNL_COPY_META:
674 case NFULNL_COPY_NONE:
675 data_len = 0;
676 break;
677
678 case NFULNL_COPY_PACKET:
679 if (inst->copy_range == 0
680 || inst->copy_range > skb->len)
681 data_len = skb->len;
682 else
683 data_len = inst->copy_range;
684
685 size += nla_total_size(data_len);
686 break;
687
688 case NFULNL_COPY_DISABLED:
689 default:
690 goto unlock_and_release;
691 }
692
693 if (inst->skb &&
694 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
695 /* either the queue len is too high or we don't have
696 * enough room in the skb left. flush to userspace. */
697 __nfulnl_flush(inst);
698 }
699
700 if (!inst->skb) {
701 inst->skb = nfulnl_alloc_skb(inst->peer_portid, inst->nlbufsiz,
702 size);
703 if (!inst->skb)
704 goto alloc_failure;
705 }
706
707 inst->qlen++;
708
709 __build_packet_message(log, inst, skb, data_len, pf,
710 hooknum, in, out, prefix, plen);
711
712 if (inst->qlen >= qthreshold)
713 __nfulnl_flush(inst);
714 /* timer_pending always called within inst->lock, so there
715 * is no chance of a race here */
716 else if (!timer_pending(&inst->timer)) {
717 instance_get(inst);
718 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
719 add_timer(&inst->timer);
720 }
721
722 unlock_and_release:
723 spin_unlock_bh(&inst->lock);
724 instance_put(inst);
725 return;
726
727 alloc_failure:
728 /* FIXME: statistics */
729 goto unlock_and_release;
730 }
731 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
732
733 static int
734 nfulnl_rcv_nl_event(struct notifier_block *this,
735 unsigned long event, void *ptr)
736 {
737 struct netlink_notify *n = ptr;
738 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
739
740 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
741 int i;
742
743 /* destroy all instances for this portid */
744 spin_lock_bh(&log->instances_lock);
745 for (i = 0; i < INSTANCE_BUCKETS; i++) {
746 struct hlist_node *t2;
747 struct nfulnl_instance *inst;
748 struct hlist_head *head = &log->instance_table[i];
749
750 hlist_for_each_entry_safe(inst, t2, head, hlist) {
751 if (n->portid == inst->peer_portid)
752 __instance_destroy(inst);
753 }
754 }
755 spin_unlock_bh(&log->instances_lock);
756 }
757 return NOTIFY_DONE;
758 }
759
760 static struct notifier_block nfulnl_rtnl_notifier = {
761 .notifier_call = nfulnl_rcv_nl_event,
762 };
763
764 static int
765 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
766 const struct nlmsghdr *nlh,
767 const struct nlattr * const nfqa[])
768 {
769 return -ENOTSUPP;
770 }
771
772 static struct nf_logger nfulnl_logger __read_mostly = {
773 .name = "nfnetlink_log",
774 .logfn = &nfulnl_log_packet,
775 .me = THIS_MODULE,
776 };
777
778 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
779 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
780 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
781 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
782 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
783 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
784 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
785 };
786
787 static int
788 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
789 const struct nlmsghdr *nlh,
790 const struct nlattr * const nfula[])
791 {
792 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
793 u_int16_t group_num = ntohs(nfmsg->res_id);
794 struct nfulnl_instance *inst;
795 struct nfulnl_msg_config_cmd *cmd = NULL;
796 struct net *net = sock_net(ctnl);
797 struct nfnl_log_net *log = nfnl_log_pernet(net);
798 int ret = 0;
799
800 if (nfula[NFULA_CFG_CMD]) {
801 u_int8_t pf = nfmsg->nfgen_family;
802 cmd = nla_data(nfula[NFULA_CFG_CMD]);
803
804 /* Commands without queue context */
805 switch (cmd->command) {
806 case NFULNL_CFG_CMD_PF_BIND:
807 return nf_log_bind_pf(net, pf, &nfulnl_logger);
808 case NFULNL_CFG_CMD_PF_UNBIND:
809 nf_log_unbind_pf(net, pf);
810 return 0;
811 }
812 }
813
814 inst = instance_lookup_get(log, group_num);
815 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
816 ret = -EPERM;
817 goto out_put;
818 }
819
820 if (cmd != NULL) {
821 switch (cmd->command) {
822 case NFULNL_CFG_CMD_BIND:
823 if (inst) {
824 ret = -EBUSY;
825 goto out_put;
826 }
827
828 inst = instance_create(net, group_num,
829 NETLINK_CB(skb).portid,
830 sk_user_ns(NETLINK_CB(skb).sk));
831 if (IS_ERR(inst)) {
832 ret = PTR_ERR(inst);
833 goto out;
834 }
835 break;
836 case NFULNL_CFG_CMD_UNBIND:
837 if (!inst) {
838 ret = -ENODEV;
839 goto out;
840 }
841
842 instance_destroy(log, inst);
843 goto out_put;
844 default:
845 ret = -ENOTSUPP;
846 break;
847 }
848 }
849
850 if (nfula[NFULA_CFG_MODE]) {
851 struct nfulnl_msg_config_mode *params;
852 params = nla_data(nfula[NFULA_CFG_MODE]);
853
854 if (!inst) {
855 ret = -ENODEV;
856 goto out;
857 }
858 nfulnl_set_mode(inst, params->copy_mode,
859 ntohl(params->copy_range));
860 }
861
862 if (nfula[NFULA_CFG_TIMEOUT]) {
863 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
864
865 if (!inst) {
866 ret = -ENODEV;
867 goto out;
868 }
869 nfulnl_set_timeout(inst, ntohl(timeout));
870 }
871
872 if (nfula[NFULA_CFG_NLBUFSIZ]) {
873 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
874
875 if (!inst) {
876 ret = -ENODEV;
877 goto out;
878 }
879 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
880 }
881
882 if (nfula[NFULA_CFG_QTHRESH]) {
883 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
884
885 if (!inst) {
886 ret = -ENODEV;
887 goto out;
888 }
889 nfulnl_set_qthresh(inst, ntohl(qthresh));
890 }
891
892 if (nfula[NFULA_CFG_FLAGS]) {
893 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
894
895 if (!inst) {
896 ret = -ENODEV;
897 goto out;
898 }
899 nfulnl_set_flags(inst, ntohs(flags));
900 }
901
902 out_put:
903 instance_put(inst);
904 out:
905 return ret;
906 }
907
908 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
909 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
910 .attr_count = NFULA_MAX, },
911 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
912 .attr_count = NFULA_CFG_MAX,
913 .policy = nfula_cfg_policy },
914 };
915
916 static const struct nfnetlink_subsystem nfulnl_subsys = {
917 .name = "log",
918 .subsys_id = NFNL_SUBSYS_ULOG,
919 .cb_count = NFULNL_MSG_MAX,
920 .cb = nfulnl_cb,
921 };
922
923 #ifdef CONFIG_PROC_FS
924 struct iter_state {
925 struct seq_net_private p;
926 unsigned int bucket;
927 };
928
929 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
930 {
931 struct nfnl_log_net *log;
932 if (!st)
933 return NULL;
934
935 log = nfnl_log_pernet(net);
936
937 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
938 struct hlist_head *head = &log->instance_table[st->bucket];
939
940 if (!hlist_empty(head))
941 return rcu_dereference_bh(hlist_first_rcu(head));
942 }
943 return NULL;
944 }
945
946 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
947 struct hlist_node *h)
948 {
949 h = rcu_dereference_bh(hlist_next_rcu(h));
950 while (!h) {
951 struct nfnl_log_net *log;
952 struct hlist_head *head;
953
954 if (++st->bucket >= INSTANCE_BUCKETS)
955 return NULL;
956
957 log = nfnl_log_pernet(net);
958 head = &log->instance_table[st->bucket];
959 h = rcu_dereference_bh(hlist_first_rcu(head));
960 }
961 return h;
962 }
963
964 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
965 loff_t pos)
966 {
967 struct hlist_node *head;
968 head = get_first(net, st);
969
970 if (head)
971 while (pos && (head = get_next(net, st, head)))
972 pos--;
973 return pos ? NULL : head;
974 }
975
976 static void *seq_start(struct seq_file *s, loff_t *pos)
977 __acquires(rcu_bh)
978 {
979 rcu_read_lock_bh();
980 return get_idx(seq_file_net(s), s->private, *pos);
981 }
982
983 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
984 {
985 (*pos)++;
986 return get_next(seq_file_net(s), s->private, v);
987 }
988
989 static void seq_stop(struct seq_file *s, void *v)
990 __releases(rcu_bh)
991 {
992 rcu_read_unlock_bh();
993 }
994
995 static int seq_show(struct seq_file *s, void *v)
996 {
997 const struct nfulnl_instance *inst = v;
998
999 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
1000 inst->group_num,
1001 inst->peer_portid, inst->qlen,
1002 inst->copy_mode, inst->copy_range,
1003 inst->flushtimeout, atomic_read(&inst->use));
1004 }
1005
1006 static const struct seq_operations nful_seq_ops = {
1007 .start = seq_start,
1008 .next = seq_next,
1009 .stop = seq_stop,
1010 .show = seq_show,
1011 };
1012
1013 static int nful_open(struct inode *inode, struct file *file)
1014 {
1015 return seq_open_net(inode, file, &nful_seq_ops,
1016 sizeof(struct iter_state));
1017 }
1018
1019 static const struct file_operations nful_file_ops = {
1020 .owner = THIS_MODULE,
1021 .open = nful_open,
1022 .read = seq_read,
1023 .llseek = seq_lseek,
1024 .release = seq_release_net,
1025 };
1026
1027 #endif /* PROC_FS */
1028
1029 static int __net_init nfnl_log_net_init(struct net *net)
1030 {
1031 unsigned int i;
1032 struct nfnl_log_net *log = nfnl_log_pernet(net);
1033
1034 for (i = 0; i < INSTANCE_BUCKETS; i++)
1035 INIT_HLIST_HEAD(&log->instance_table[i]);
1036 spin_lock_init(&log->instances_lock);
1037
1038 #ifdef CONFIG_PROC_FS
1039 if (!proc_create("nfnetlink_log", 0440,
1040 net->nf.proc_netfilter, &nful_file_ops))
1041 return -ENOMEM;
1042 #endif
1043 return 0;
1044 }
1045
1046 static void __net_exit nfnl_log_net_exit(struct net *net)
1047 {
1048 #ifdef CONFIG_PROC_FS
1049 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1050 #endif
1051 }
1052
1053 static struct pernet_operations nfnl_log_net_ops = {
1054 .init = nfnl_log_net_init,
1055 .exit = nfnl_log_net_exit,
1056 .id = &nfnl_log_net_id,
1057 .size = sizeof(struct nfnl_log_net),
1058 };
1059
1060 static int __init nfnetlink_log_init(void)
1061 {
1062 int status = -ENOMEM;
1063
1064 /* it's not really all that important to have a random value, so
1065 * we can do this from the init function, even if there hasn't
1066 * been that much entropy yet */
1067 get_random_bytes(&hash_init, sizeof(hash_init));
1068
1069 netlink_register_notifier(&nfulnl_rtnl_notifier);
1070 status = nfnetlink_subsys_register(&nfulnl_subsys);
1071 if (status < 0) {
1072 pr_err("log: failed to create netlink socket\n");
1073 goto cleanup_netlink_notifier;
1074 }
1075
1076 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1077 if (status < 0) {
1078 pr_err("log: failed to register logger\n");
1079 goto cleanup_subsys;
1080 }
1081
1082 status = register_pernet_subsys(&nfnl_log_net_ops);
1083 if (status < 0) {
1084 pr_err("log: failed to register pernet ops\n");
1085 goto cleanup_logger;
1086 }
1087 return status;
1088
1089 cleanup_logger:
1090 nf_log_unregister(&nfulnl_logger);
1091 cleanup_subsys:
1092 nfnetlink_subsys_unregister(&nfulnl_subsys);
1093 cleanup_netlink_notifier:
1094 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1095 return status;
1096 }
1097
1098 static void __exit nfnetlink_log_fini(void)
1099 {
1100 unregister_pernet_subsys(&nfnl_log_net_ops);
1101 nf_log_unregister(&nfulnl_logger);
1102 nfnetlink_subsys_unregister(&nfulnl_subsys);
1103 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1104 }
1105
1106 MODULE_DESCRIPTION("netfilter userspace logging");
1107 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1108 MODULE_LICENSE("GPL");
1109 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1110
1111 module_init(nfnetlink_log_init);
1112 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support