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fix a kmap leak in virtio_console
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
bloba155d19a225edcfb4b1a550ebc898f40d51c564d
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(struct net *net, u32 peer_portid, unsigned int inst_size,
323 unsigned int pkt_size)
324 {
325 struct sk_buff *skb;
326 unsigned int n;
327
328 /* alloc skb which should be big enough for a whole multipart
329 * message. WARNING: has to be <= 128k due to slab restrictions */
330
331 n = max(inst_size, pkt_size);
332 skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
333 if (!skb) {
334 if (n > pkt_size) {
335 /* try to allocate only as much as we need for current
336 * packet */
337
338 skb = nfnetlink_alloc_skb(net, pkt_size,
339 peer_portid, GFP_ATOMIC);
340 if (!skb)
341 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
342 pkt_size);
343 }
344 }
345
346 return skb;
347 }
348
349 static int
350 __nfulnl_send(struct nfulnl_instance *inst)
351 {
352 int status = -1;
353
354 if (inst->qlen > 1) {
355 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
356 NLMSG_DONE,
357 sizeof(struct nfgenmsg),
358 0);
359 if (!nlh)
360 goto out;
361 }
362 status = nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
363 MSG_DONTWAIT);
364
365 inst->qlen = 0;
366 inst->skb = NULL;
367 out:
368 return status;
369 }
370
371 static void
372 __nfulnl_flush(struct nfulnl_instance *inst)
373 {
374 /* timer holds a reference */
375 if (del_timer(&inst->timer))
376 instance_put(inst);
377 if (inst->skb)
378 __nfulnl_send(inst);
379 }
380
381 static void
382 nfulnl_timer(unsigned long data)
383 {
384 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
385
386 spin_lock_bh(&inst->lock);
387 if (inst->skb)
388 __nfulnl_send(inst);
389 spin_unlock_bh(&inst->lock);
390 instance_put(inst);
391 }
392
393 /* This is an inline function, we don't really care about a long
394 * list of arguments */
395 static inline int
396 __build_packet_message(struct nfnl_log_net *log,
397 struct nfulnl_instance *inst,
398 const struct sk_buff *skb,
399 unsigned int data_len,
400 u_int8_t pf,
401 unsigned int hooknum,
402 const struct net_device *indev,
403 const struct net_device *outdev,
404 const char *prefix, unsigned int plen)
405 {
406 struct nfulnl_msg_packet_hdr pmsg;
407 struct nlmsghdr *nlh;
408 struct nfgenmsg *nfmsg;
409 sk_buff_data_t old_tail = inst->skb->tail;
410 struct sock *sk;
411 const unsigned char *hwhdrp;
412
413 nlh = nlmsg_put(inst->skb, 0, 0,
414 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
415 sizeof(struct nfgenmsg), 0);
416 if (!nlh)
417 return -1;
418 nfmsg = nlmsg_data(nlh);
419 nfmsg->nfgen_family = pf;
420 nfmsg->version = NFNETLINK_V0;
421 nfmsg->res_id = htons(inst->group_num);
422
423 memset(&pmsg, 0, sizeof(pmsg));
424 pmsg.hw_protocol = skb->protocol;
425 pmsg.hook = hooknum;
426
427 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
428 goto nla_put_failure;
429
430 if (prefix &&
431 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
432 goto nla_put_failure;
433
434 if (indev) {
435 #ifndef CONFIG_BRIDGE_NETFILTER
436 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
437 htonl(indev->ifindex)))
438 goto nla_put_failure;
439 #else
440 if (pf == PF_BRIDGE) {
441 /* Case 1: outdev is physical input device, we need to
442 * look for bridge group (when called from
443 * netfilter_bridge) */
444 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
445 htonl(indev->ifindex)) ||
446 /* this is the bridge group "brX" */
447 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
448 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
449 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
450 goto nla_put_failure;
451 } else {
452 /* Case 2: indev is bridge group, we need to look for
453 * physical device (when called from ipv4) */
454 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
455 htonl(indev->ifindex)))
456 goto nla_put_failure;
457 if (skb->nf_bridge && skb->nf_bridge->physindev &&
458 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
459 htonl(skb->nf_bridge->physindev->ifindex)))
460 goto nla_put_failure;
461 }
462 #endif
463 }
464
465 if (outdev) {
466 #ifndef CONFIG_BRIDGE_NETFILTER
467 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
468 htonl(outdev->ifindex)))
469 goto nla_put_failure;
470 #else
471 if (pf == PF_BRIDGE) {
472 /* Case 1: outdev is physical output device, we need to
473 * look for bridge group (when called from
474 * netfilter_bridge) */
475 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
476 htonl(outdev->ifindex)) ||
477 /* this is the bridge group "brX" */
478 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
479 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
480 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
481 goto nla_put_failure;
482 } else {
483 /* Case 2: indev is a bridge group, we need to look
484 * for physical device (when called from ipv4) */
485 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
486 htonl(outdev->ifindex)))
487 goto nla_put_failure;
488 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
489 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
490 htonl(skb->nf_bridge->physoutdev->ifindex)))
491 goto nla_put_failure;
492 }
493 #endif
494 }
495
496 if (skb->mark &&
497 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
498 goto nla_put_failure;
499
500 if (indev && skb->dev &&
501 skb->mac_header != skb->network_header) {
502 struct nfulnl_msg_packet_hw phw;
503 int len;
504
505 memset(&phw, 0, sizeof(phw));
506 len = dev_parse_header(skb, phw.hw_addr);
507 if (len > 0) {
508 phw.hw_addrlen = htons(len);
509 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
510 goto nla_put_failure;
511 }
512 }
513
514 if (indev && skb_mac_header_was_set(skb)) {
515 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
516 nla_put_be16(inst->skb, NFULA_HWLEN,
517 htons(skb->dev->hard_header_len)))
518 goto nla_put_failure;
519
520 hwhdrp = skb_mac_header(skb);
521
522 if (skb->dev->type == ARPHRD_SIT)
523 hwhdrp -= ETH_HLEN;
524
525 if (hwhdrp >= skb->head &&
526 nla_put(inst->skb, NFULA_HWHEADER,
527 skb->dev->hard_header_len, hwhdrp))
528 goto nla_put_failure;
529 }
530
531 if (skb->tstamp.tv64) {
532 struct nfulnl_msg_packet_timestamp ts;
533 struct timeval tv = ktime_to_timeval(skb->tstamp);
534 ts.sec = cpu_to_be64(tv.tv_sec);
535 ts.usec = cpu_to_be64(tv.tv_usec);
536
537 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
538 goto nla_put_failure;
539 }
540
541 /* UID */
542 sk = skb->sk;
543 if (sk && sk->sk_state != TCP_TIME_WAIT) {
544 read_lock_bh(&sk->sk_callback_lock);
545 if (sk->sk_socket && sk->sk_socket->file) {
546 struct file *file = sk->sk_socket->file;
547 const struct cred *cred = file->f_cred;
548 struct user_namespace *user_ns = inst->peer_user_ns;
549 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
550 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
551 read_unlock_bh(&sk->sk_callback_lock);
552 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
553 nla_put_be32(inst->skb, NFULA_GID, gid))
554 goto nla_put_failure;
555 } else
556 read_unlock_bh(&sk->sk_callback_lock);
557 }
558
559 /* local sequence number */
560 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
561 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
562 goto nla_put_failure;
563
564 /* global sequence number */
565 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
566 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
567 htonl(atomic_inc_return(&log->global_seq))))
568 goto nla_put_failure;
569
570 if (data_len) {
571 struct nlattr *nla;
572 int size = nla_attr_size(data_len);
573
574 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
575 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
576 return -1;
577 }
578
579 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
580 nla->nla_type = NFULA_PAYLOAD;
581 nla->nla_len = size;
582
583 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
584 BUG();
585 }
586
587 nlh->nlmsg_len = inst->skb->tail - old_tail;
588 return 0;
589
590 nla_put_failure:
591 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
592 return -1;
593 }
594
595 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
596
597 static struct nf_loginfo default_loginfo = {
598 .type = NF_LOG_TYPE_ULOG,
599 .u = {
600 .ulog = {
601 .copy_len = 0xffff,
602 .group = 0,
603 .qthreshold = 1,
604 },
605 },
606 };
607
608 /* log handler for internal netfilter logging api */
609 void
610 nfulnl_log_packet(struct net *net,
611 u_int8_t pf,
612 unsigned int hooknum,
613 const struct sk_buff *skb,
614 const struct net_device *in,
615 const struct net_device *out,
616 const struct nf_loginfo *li_user,
617 const char *prefix)
618 {
619 unsigned int size, data_len;
620 struct nfulnl_instance *inst;
621 const struct nf_loginfo *li;
622 unsigned int qthreshold;
623 unsigned int plen;
624 struct nfnl_log_net *log = nfnl_log_pernet(net);
625
626 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
627 li = li_user;
628 else
629 li = &default_loginfo;
630
631 inst = instance_lookup_get(log, li->u.ulog.group);
632 if (!inst)
633 return;
634
635 plen = 0;
636 if (prefix)
637 plen = strlen(prefix) + 1;
638
639 /* FIXME: do we want to make the size calculation conditional based on
640 * what is actually present? way more branches and checks, but more
641 * memory efficient... */
642 size = nlmsg_total_size(sizeof(struct nfgenmsg))
643 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
644 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
645 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
646 #ifdef CONFIG_BRIDGE_NETFILTER
647 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
648 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
649 #endif
650 + nla_total_size(sizeof(u_int32_t)) /* mark */
651 + nla_total_size(sizeof(u_int32_t)) /* uid */
652 + nla_total_size(sizeof(u_int32_t)) /* gid */
653 + nla_total_size(plen) /* prefix */
654 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
655 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
656
657 if (in && skb_mac_header_was_set(skb)) {
658 size += nla_total_size(skb->dev->hard_header_len)
659 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
660 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
661 }
662
663 spin_lock_bh(&inst->lock);
664
665 if (inst->flags & NFULNL_CFG_F_SEQ)
666 size += nla_total_size(sizeof(u_int32_t));
667 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
668 size += nla_total_size(sizeof(u_int32_t));
669
670 qthreshold = inst->qthreshold;
671 /* per-rule qthreshold overrides per-instance */
672 if (li->u.ulog.qthreshold)
673 if (qthreshold > li->u.ulog.qthreshold)
674 qthreshold = li->u.ulog.qthreshold;
675
676
677 switch (inst->copy_mode) {
678 case NFULNL_COPY_META:
679 case NFULNL_COPY_NONE:
680 data_len = 0;
681 break;
682
683 case NFULNL_COPY_PACKET:
684 if (inst->copy_range == 0
685 || inst->copy_range > skb->len)
686 data_len = skb->len;
687 else
688 data_len = inst->copy_range;
689
690 size += nla_total_size(data_len);
691 break;
692
693 case NFULNL_COPY_DISABLED:
694 default:
695 goto unlock_and_release;
696 }
697
698 if (inst->skb &&
699 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
700 /* either the queue len is too high or we don't have
701 * enough room in the skb left. flush to userspace. */
702 __nfulnl_flush(inst);
703 }
704
705 if (!inst->skb) {
706 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
707 inst->nlbufsiz, size);
708 if (!inst->skb)
709 goto alloc_failure;
710 }
711
712 inst->qlen++;
713
714 __build_packet_message(log, inst, skb, data_len, pf,
715 hooknum, in, out, prefix, plen);
716
717 if (inst->qlen >= qthreshold)
718 __nfulnl_flush(inst);
719 /* timer_pending always called within inst->lock, so there
720 * is no chance of a race here */
721 else if (!timer_pending(&inst->timer)) {
722 instance_get(inst);
723 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
724 add_timer(&inst->timer);
725 }
726
727 unlock_and_release:
728 spin_unlock_bh(&inst->lock);
729 instance_put(inst);
730 return;
731
732 alloc_failure:
733 /* FIXME: statistics */
734 goto unlock_and_release;
735 }
736 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
737
738 static int
739 nfulnl_rcv_nl_event(struct notifier_block *this,
740 unsigned long event, void *ptr)
741 {
742 struct netlink_notify *n = ptr;
743 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
744
745 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
746 int i;
747
748 /* destroy all instances for this portid */
749 spin_lock_bh(&log->instances_lock);
750 for (i = 0; i < INSTANCE_BUCKETS; i++) {
751 struct hlist_node *t2;
752 struct nfulnl_instance *inst;
753 struct hlist_head *head = &log->instance_table[i];
754
755 hlist_for_each_entry_safe(inst, t2, head, hlist) {
756 if (n->portid == inst->peer_portid)
757 __instance_destroy(inst);
758 }
759 }
760 spin_unlock_bh(&log->instances_lock);
761 }
762 return NOTIFY_DONE;
763 }
764
765 static struct notifier_block nfulnl_rtnl_notifier = {
766 .notifier_call = nfulnl_rcv_nl_event,
767 };
768
769 static int
770 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
771 const struct nlmsghdr *nlh,
772 const struct nlattr * const nfqa[])
773 {
774 return -ENOTSUPP;
775 }
776
777 static struct nf_logger nfulnl_logger __read_mostly = {
778 .name = "nfnetlink_log",
779 .logfn = &nfulnl_log_packet,
780 .me = THIS_MODULE,
781 };
782
783 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
784 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
785 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
786 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
787 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
788 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
789 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
790 };
791
792 static int
793 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
794 const struct nlmsghdr *nlh,
795 const struct nlattr * const nfula[])
796 {
797 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
798 u_int16_t group_num = ntohs(nfmsg->res_id);
799 struct nfulnl_instance *inst;
800 struct nfulnl_msg_config_cmd *cmd = NULL;
801 struct net *net = sock_net(ctnl);
802 struct nfnl_log_net *log = nfnl_log_pernet(net);
803 int ret = 0;
804
805 if (nfula[NFULA_CFG_CMD]) {
806 u_int8_t pf = nfmsg->nfgen_family;
807 cmd = nla_data(nfula[NFULA_CFG_CMD]);
808
809 /* Commands without queue context */
810 switch (cmd->command) {
811 case NFULNL_CFG_CMD_PF_BIND:
812 return nf_log_bind_pf(net, pf, &nfulnl_logger);
813 case NFULNL_CFG_CMD_PF_UNBIND:
814 nf_log_unbind_pf(net, pf);
815 return 0;
816 }
817 }
818
819 inst = instance_lookup_get(log, group_num);
820 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
821 ret = -EPERM;
822 goto out_put;
823 }
824
825 if (cmd != NULL) {
826 switch (cmd->command) {
827 case NFULNL_CFG_CMD_BIND:
828 if (inst) {
829 ret = -EBUSY;
830 goto out_put;
831 }
832
833 inst = instance_create(net, group_num,
834 NETLINK_CB(skb).portid,
835 sk_user_ns(NETLINK_CB(skb).sk));
836 if (IS_ERR(inst)) {
837 ret = PTR_ERR(inst);
838 goto out;
839 }
840 break;
841 case NFULNL_CFG_CMD_UNBIND:
842 if (!inst) {
843 ret = -ENODEV;
844 goto out;
845 }
846
847 instance_destroy(log, inst);
848 goto out_put;
849 default:
850 ret = -ENOTSUPP;
851 break;
852 }
853 }
854
855 if (nfula[NFULA_CFG_MODE]) {
856 struct nfulnl_msg_config_mode *params;
857 params = nla_data(nfula[NFULA_CFG_MODE]);
858
859 if (!inst) {
860 ret = -ENODEV;
861 goto out;
862 }
863 nfulnl_set_mode(inst, params->copy_mode,
864 ntohl(params->copy_range));
865 }
866
867 if (nfula[NFULA_CFG_TIMEOUT]) {
868 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
869
870 if (!inst) {
871 ret = -ENODEV;
872 goto out;
873 }
874 nfulnl_set_timeout(inst, ntohl(timeout));
875 }
876
877 if (nfula[NFULA_CFG_NLBUFSIZ]) {
878 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
879
880 if (!inst) {
881 ret = -ENODEV;
882 goto out;
883 }
884 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
885 }
886
887 if (nfula[NFULA_CFG_QTHRESH]) {
888 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
889
890 if (!inst) {
891 ret = -ENODEV;
892 goto out;
893 }
894 nfulnl_set_qthresh(inst, ntohl(qthresh));
895 }
896
897 if (nfula[NFULA_CFG_FLAGS]) {
898 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
899
900 if (!inst) {
901 ret = -ENODEV;
902 goto out;
903 }
904 nfulnl_set_flags(inst, ntohs(flags));
905 }
906
907 out_put:
908 instance_put(inst);
909 out:
910 return ret;
911 }
912
913 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
914 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
915 .attr_count = NFULA_MAX, },
916 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
917 .attr_count = NFULA_CFG_MAX,
918 .policy = nfula_cfg_policy },
919 };
920
921 static const struct nfnetlink_subsystem nfulnl_subsys = {
922 .name = "log",
923 .subsys_id = NFNL_SUBSYS_ULOG,
924 .cb_count = NFULNL_MSG_MAX,
925 .cb = nfulnl_cb,
926 };
927
928 #ifdef CONFIG_PROC_FS
929 struct iter_state {
930 struct seq_net_private p;
931 unsigned int bucket;
932 };
933
934 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
935 {
936 struct nfnl_log_net *log;
937 if (!st)
938 return NULL;
939
940 log = nfnl_log_pernet(net);
941
942 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
943 struct hlist_head *head = &log->instance_table[st->bucket];
944
945 if (!hlist_empty(head))
946 return rcu_dereference_bh(hlist_first_rcu(head));
947 }
948 return NULL;
949 }
950
951 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
952 struct hlist_node *h)
953 {
954 h = rcu_dereference_bh(hlist_next_rcu(h));
955 while (!h) {
956 struct nfnl_log_net *log;
957 struct hlist_head *head;
958
959 if (++st->bucket >= INSTANCE_BUCKETS)
960 return NULL;
961
962 log = nfnl_log_pernet(net);
963 head = &log->instance_table[st->bucket];
964 h = rcu_dereference_bh(hlist_first_rcu(head));
965 }
966 return h;
967 }
968
969 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
970 loff_t pos)
971 {
972 struct hlist_node *head;
973 head = get_first(net, st);
974
975 if (head)
976 while (pos && (head = get_next(net, st, head)))
977 pos--;
978 return pos ? NULL : head;
979 }
980
981 static void *seq_start(struct seq_file *s, loff_t *pos)
982 __acquires(rcu_bh)
983 {
984 rcu_read_lock_bh();
985 return get_idx(seq_file_net(s), s->private, *pos);
986 }
987
988 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
989 {
990 (*pos)++;
991 return get_next(seq_file_net(s), s->private, v);
992 }
993
994 static void seq_stop(struct seq_file *s, void *v)
995 __releases(rcu_bh)
996 {
997 rcu_read_unlock_bh();
998 }
999
1000 static int seq_show(struct seq_file *s, void *v)
1001 {
1002 const struct nfulnl_instance *inst = v;
1003
1004 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
1005 inst->group_num,
1006 inst->peer_portid, inst->qlen,
1007 inst->copy_mode, inst->copy_range,
1008 inst->flushtimeout, atomic_read(&inst->use));
1009 }
1010
1011 static const struct seq_operations nful_seq_ops = {
1012 .start = seq_start,
1013 .next = seq_next,
1014 .stop = seq_stop,
1015 .show = seq_show,
1016 };
1017
1018 static int nful_open(struct inode *inode, struct file *file)
1019 {
1020 return seq_open_net(inode, file, &nful_seq_ops,
1021 sizeof(struct iter_state));
1022 }
1023
1024 static const struct file_operations nful_file_ops = {
1025 .owner = THIS_MODULE,
1026 .open = nful_open,
1027 .read = seq_read,
1028 .llseek = seq_lseek,
1029 .release = seq_release_net,
1030 };
1031
1032 #endif /* PROC_FS */
1033
1034 static int __net_init nfnl_log_net_init(struct net *net)
1035 {
1036 unsigned int i;
1037 struct nfnl_log_net *log = nfnl_log_pernet(net);
1038
1039 for (i = 0; i < INSTANCE_BUCKETS; i++)
1040 INIT_HLIST_HEAD(&log->instance_table[i]);
1041 spin_lock_init(&log->instances_lock);
1042
1043 #ifdef CONFIG_PROC_FS
1044 if (!proc_create("nfnetlink_log", 0440,
1045 net->nf.proc_netfilter, &nful_file_ops))
1046 return -ENOMEM;
1047 #endif
1048 return 0;
1049 }
1050
1051 static void __net_exit nfnl_log_net_exit(struct net *net)
1052 {
1053 #ifdef CONFIG_PROC_FS
1054 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1055 #endif
1056 nf_log_unset(net, &nfulnl_logger);
1057 }
1058
1059 static struct pernet_operations nfnl_log_net_ops = {
1060 .init = nfnl_log_net_init,
1061 .exit = nfnl_log_net_exit,
1062 .id = &nfnl_log_net_id,
1063 .size = sizeof(struct nfnl_log_net),
1064 };
1065
1066 static int __init nfnetlink_log_init(void)
1067 {
1068 int status = -ENOMEM;
1069
1070 /* it's not really all that important to have a random value, so
1071 * we can do this from the init function, even if there hasn't
1072 * been that much entropy yet */
1073 get_random_bytes(&hash_init, sizeof(hash_init));
1074
1075 netlink_register_notifier(&nfulnl_rtnl_notifier);
1076 status = nfnetlink_subsys_register(&nfulnl_subsys);
1077 if (status < 0) {
1078 pr_err("log: failed to create netlink socket\n");
1079 goto cleanup_netlink_notifier;
1080 }
1081
1082 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1083 if (status < 0) {
1084 pr_err("log: failed to register logger\n");
1085 goto cleanup_subsys;
1086 }
1087
1088 status = register_pernet_subsys(&nfnl_log_net_ops);
1089 if (status < 0) {
1090 pr_err("log: failed to register pernet ops\n");
1091 goto cleanup_logger;
1092 }
1093 return status;
1094
1095 cleanup_logger:
1096 nf_log_unregister(&nfulnl_logger);
1097 cleanup_subsys:
1098 nfnetlink_subsys_unregister(&nfulnl_subsys);
1099 cleanup_netlink_notifier:
1100 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1101 return status;
1102 }
1103
1104 static void __exit nfnetlink_log_fini(void)
1105 {
1106 unregister_pernet_subsys(&nfnl_log_net_ops);
1107 nf_log_unregister(&nfulnl_logger);
1108 nfnetlink_subsys_unregister(&nfulnl_subsys);
1109 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1110 }
1111
1112 MODULE_DESCRIPTION("netfilter userspace logging");
1113 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1114 MODULE_LICENSE("GPL");
1115 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1116
1117 module_init(nfnetlink_log_init);
1118 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support