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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64...
[deliverable/linux.git] / net / netfilter / nfnetlink_log.c
1 /*
2 * This is a module which is used for logging packets to userspace via
3 * nfetlink.
4 *
5 * (C) 2005 by Harald Welte <laforge@netfilter.org>
6 * (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
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18 #include <linux/module.h>
19 #include <linux/skbuff.h>
20 #include <linux/if_arp.h>
21 #include <linux/init.h>
22 #include <linux/ip.h>
23 #include <linux/ipv6.h>
24 #include <linux/netdevice.h>
25 #include <linux/netfilter.h>
26 #include <linux/netfilter_bridge.h>
27 #include <net/netlink.h>
28 #include <linux/netfilter/nfnetlink.h>
29 #include <linux/netfilter/nfnetlink_log.h>
30 #include <linux/spinlock.h>
31 #include <linux/sysctl.h>
32 #include <linux/proc_fs.h>
33 #include <linux/security.h>
34 #include <linux/list.h>
35 #include <linux/slab.h>
36 #include <net/sock.h>
37 #include <net/netfilter/nf_log.h>
38 #include <net/netns/generic.h>
39 #include <net/netfilter/nfnetlink_log.h>
40
41 #include <linux/atomic.h>
42
43 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
44 #include "../bridge/br_private.h"
45 #endif
46
47 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
48 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
49 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
50 /* max packet size is limited by 16-bit struct nfattr nfa_len field */
51 #define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
52
53 #define PRINTR(x, args...) do { if (net_ratelimit()) \
54 printk(x, ## args); } while (0);
55
56 struct nfulnl_instance {
57 struct hlist_node hlist; /* global list of instances */
58 spinlock_t lock;
59 atomic_t use; /* use count */
60
61 unsigned int qlen; /* number of nlmsgs in skb */
62 struct sk_buff *skb; /* pre-allocatd skb */
63 struct timer_list timer;
64 struct net *net;
65 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
66 u32 peer_portid; /* PORTID of the peer process */
67
68 /* configurable parameters */
69 unsigned int flushtimeout; /* timeout until queue flush */
70 unsigned int nlbufsiz; /* netlink buffer allocation size */
71 unsigned int qthreshold; /* threshold of the queue */
72 u_int32_t copy_range;
73 u_int32_t seq; /* instance-local sequential counter */
74 u_int16_t group_num; /* number of this queue */
75 u_int16_t flags;
76 u_int8_t copy_mode;
77 struct rcu_head rcu;
78 };
79
80 #define INSTANCE_BUCKETS 16
81
82 static int nfnl_log_net_id __read_mostly;
83
84 struct nfnl_log_net {
85 spinlock_t instances_lock;
86 struct hlist_head instance_table[INSTANCE_BUCKETS];
87 atomic_t global_seq;
88 };
89
90 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
91 {
92 return net_generic(net, nfnl_log_net_id);
93 }
94
95 static inline u_int8_t instance_hashfn(u_int16_t group_num)
96 {
97 return ((group_num & 0xff) % INSTANCE_BUCKETS);
98 }
99
100 static struct nfulnl_instance *
101 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
102 {
103 struct hlist_head *head;
104 struct nfulnl_instance *inst;
105
106 head = &log->instance_table[instance_hashfn(group_num)];
107 hlist_for_each_entry_rcu(inst, head, hlist) {
108 if (inst->group_num == group_num)
109 return inst;
110 }
111 return NULL;
112 }
113
114 static inline void
115 instance_get(struct nfulnl_instance *inst)
116 {
117 atomic_inc(&inst->use);
118 }
119
120 static struct nfulnl_instance *
121 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
122 {
123 struct nfulnl_instance *inst;
124
125 rcu_read_lock_bh();
126 inst = __instance_lookup(log, group_num);
127 if (inst && !atomic_inc_not_zero(&inst->use))
128 inst = NULL;
129 rcu_read_unlock_bh();
130
131 return inst;
132 }
133
134 static void nfulnl_instance_free_rcu(struct rcu_head *head)
135 {
136 struct nfulnl_instance *inst =
137 container_of(head, struct nfulnl_instance, rcu);
138
139 put_net(inst->net);
140 kfree(inst);
141 module_put(THIS_MODULE);
142 }
143
144 static void
145 instance_put(struct nfulnl_instance *inst)
146 {
147 if (inst && atomic_dec_and_test(&inst->use))
148 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
149 }
150
151 static void nfulnl_timer(unsigned long data);
152
153 static struct nfulnl_instance *
154 instance_create(struct net *net, u_int16_t group_num,
155 u32 portid, struct user_namespace *user_ns)
156 {
157 struct nfulnl_instance *inst;
158 struct nfnl_log_net *log = nfnl_log_pernet(net);
159 int err;
160
161 spin_lock_bh(&log->instances_lock);
162 if (__instance_lookup(log, group_num)) {
163 err = -EEXIST;
164 goto out_unlock;
165 }
166
167 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
168 if (!inst) {
169 err = -ENOMEM;
170 goto out_unlock;
171 }
172
173 if (!try_module_get(THIS_MODULE)) {
174 kfree(inst);
175 err = -EAGAIN;
176 goto out_unlock;
177 }
178
179 INIT_HLIST_NODE(&inst->hlist);
180 spin_lock_init(&inst->lock);
181 /* needs to be two, since we _put() after creation */
182 atomic_set(&inst->use, 2);
183
184 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
185
186 inst->net = get_net(net);
187 inst->peer_user_ns = user_ns;
188 inst->peer_portid = portid;
189 inst->group_num = group_num;
190
191 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
192 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
193 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
194 inst->copy_mode = NFULNL_COPY_PACKET;
195 inst->copy_range = NFULNL_COPY_RANGE_MAX;
196
197 hlist_add_head_rcu(&inst->hlist,
198 &log->instance_table[instance_hashfn(group_num)]);
199
200
201 spin_unlock_bh(&log->instances_lock);
202
203 return inst;
204
205 out_unlock:
206 spin_unlock_bh(&log->instances_lock);
207 return ERR_PTR(err);
208 }
209
210 static void __nfulnl_flush(struct nfulnl_instance *inst);
211
212 /* called with BH disabled */
213 static void
214 __instance_destroy(struct nfulnl_instance *inst)
215 {
216 /* first pull it out of the global list */
217 hlist_del_rcu(&inst->hlist);
218
219 /* then flush all pending packets from skb */
220
221 spin_lock(&inst->lock);
222
223 /* lockless readers wont be able to use us */
224 inst->copy_mode = NFULNL_COPY_DISABLED;
225
226 if (inst->skb)
227 __nfulnl_flush(inst);
228 spin_unlock(&inst->lock);
229
230 /* and finally put the refcount */
231 instance_put(inst);
232 }
233
234 static inline void
235 instance_destroy(struct nfnl_log_net *log,
236 struct nfulnl_instance *inst)
237 {
238 spin_lock_bh(&log->instances_lock);
239 __instance_destroy(inst);
240 spin_unlock_bh(&log->instances_lock);
241 }
242
243 static int
244 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
245 unsigned int range)
246 {
247 int status = 0;
248
249 spin_lock_bh(&inst->lock);
250
251 switch (mode) {
252 case NFULNL_COPY_NONE:
253 case NFULNL_COPY_META:
254 inst->copy_mode = mode;
255 inst->copy_range = 0;
256 break;
257
258 case NFULNL_COPY_PACKET:
259 inst->copy_mode = mode;
260 if (range == 0)
261 range = NFULNL_COPY_RANGE_MAX;
262 inst->copy_range = min_t(unsigned int,
263 range, NFULNL_COPY_RANGE_MAX);
264 break;
265
266 default:
267 status = -EINVAL;
268 break;
269 }
270
271 spin_unlock_bh(&inst->lock);
272
273 return status;
274 }
275
276 static int
277 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
278 {
279 int status;
280
281 spin_lock_bh(&inst->lock);
282 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
283 status = -ERANGE;
284 else if (nlbufsiz > 131072)
285 status = -ERANGE;
286 else {
287 inst->nlbufsiz = nlbufsiz;
288 status = 0;
289 }
290 spin_unlock_bh(&inst->lock);
291
292 return status;
293 }
294
295 static int
296 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
297 {
298 spin_lock_bh(&inst->lock);
299 inst->flushtimeout = timeout;
300 spin_unlock_bh(&inst->lock);
301
302 return 0;
303 }
304
305 static int
306 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
307 {
308 spin_lock_bh(&inst->lock);
309 inst->qthreshold = qthresh;
310 spin_unlock_bh(&inst->lock);
311
312 return 0;
313 }
314
315 static int
316 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
317 {
318 spin_lock_bh(&inst->lock);
319 inst->flags = flags;
320 spin_unlock_bh(&inst->lock);
321
322 return 0;
323 }
324
325 static struct sk_buff *
326 nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
327 unsigned int pkt_size)
328 {
329 struct sk_buff *skb;
330 unsigned int n;
331
332 /* alloc skb which should be big enough for a whole multipart
333 * message. WARNING: has to be <= 128k due to slab restrictions */
334
335 n = max(inst_size, pkt_size);
336 skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
337 if (!skb) {
338 if (n > pkt_size) {
339 /* try to allocate only as much as we need for current
340 * packet */
341
342 skb = nfnetlink_alloc_skb(net, pkt_size,
343 peer_portid, GFP_ATOMIC);
344 }
345 }
346
347 return skb;
348 }
349
350 static void
351 __nfulnl_send(struct nfulnl_instance *inst)
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 (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
359 inst->skb->len, skb_tailroom(inst->skb))) {
360 kfree_skb(inst->skb);
361 goto out;
362 }
363 }
364 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
365 MSG_DONTWAIT);
366 out:
367 inst->qlen = 0;
368 inst->skb = NULL;
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 #if !IS_ENABLED(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 struct net_device *physindev;
453
454 /* Case 2: indev is bridge group, we need to look for
455 * physical device (when called from ipv4) */
456 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
457 htonl(indev->ifindex)))
458 goto nla_put_failure;
459
460 physindev = nf_bridge_get_physindev(skb);
461 if (physindev &&
462 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
463 htonl(physindev->ifindex)))
464 goto nla_put_failure;
465 }
466 #endif
467 }
468
469 if (outdev) {
470 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
471 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
472 htonl(outdev->ifindex)))
473 goto nla_put_failure;
474 #else
475 if (pf == PF_BRIDGE) {
476 /* Case 1: outdev is physical output device, we need to
477 * look for bridge group (when called from
478 * netfilter_bridge) */
479 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
480 htonl(outdev->ifindex)) ||
481 /* this is the bridge group "brX" */
482 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
483 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
484 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
485 goto nla_put_failure;
486 } else {
487 struct net_device *physoutdev;
488
489 /* Case 2: indev is a bridge group, we need to look
490 * for physical device (when called from ipv4) */
491 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
492 htonl(outdev->ifindex)))
493 goto nla_put_failure;
494
495 physoutdev = nf_bridge_get_physoutdev(skb);
496 if (physoutdev &&
497 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
498 htonl(physoutdev->ifindex)))
499 goto nla_put_failure;
500 }
501 #endif
502 }
503
504 if (skb->mark &&
505 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
506 goto nla_put_failure;
507
508 if (indev && skb->dev &&
509 skb->mac_header != skb->network_header) {
510 struct nfulnl_msg_packet_hw phw;
511 int len;
512
513 memset(&phw, 0, sizeof(phw));
514 len = dev_parse_header(skb, phw.hw_addr);
515 if (len > 0) {
516 phw.hw_addrlen = htons(len);
517 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
518 goto nla_put_failure;
519 }
520 }
521
522 if (indev && skb_mac_header_was_set(skb)) {
523 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
524 nla_put_be16(inst->skb, NFULA_HWLEN,
525 htons(skb->dev->hard_header_len)))
526 goto nla_put_failure;
527
528 hwhdrp = skb_mac_header(skb);
529
530 if (skb->dev->type == ARPHRD_SIT)
531 hwhdrp -= ETH_HLEN;
532
533 if (hwhdrp >= skb->head &&
534 nla_put(inst->skb, NFULA_HWHEADER,
535 skb->dev->hard_header_len, hwhdrp))
536 goto nla_put_failure;
537 }
538
539 if (skb->tstamp.tv64) {
540 struct nfulnl_msg_packet_timestamp ts;
541 struct timeval tv = ktime_to_timeval(skb->tstamp);
542 ts.sec = cpu_to_be64(tv.tv_sec);
543 ts.usec = cpu_to_be64(tv.tv_usec);
544
545 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
546 goto nla_put_failure;
547 }
548
549 /* UID */
550 sk = skb->sk;
551 if (sk && sk_fullsock(sk)) {
552 read_lock_bh(&sk->sk_callback_lock);
553 if (sk->sk_socket && sk->sk_socket->file) {
554 struct file *file = sk->sk_socket->file;
555 const struct cred *cred = file->f_cred;
556 struct user_namespace *user_ns = inst->peer_user_ns;
557 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
558 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
559 read_unlock_bh(&sk->sk_callback_lock);
560 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
561 nla_put_be32(inst->skb, NFULA_GID, gid))
562 goto nla_put_failure;
563 } else
564 read_unlock_bh(&sk->sk_callback_lock);
565 }
566
567 /* local sequence number */
568 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
569 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
570 goto nla_put_failure;
571
572 /* global sequence number */
573 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
574 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
575 htonl(atomic_inc_return(&log->global_seq))))
576 goto nla_put_failure;
577
578 if (data_len) {
579 struct nlattr *nla;
580 int size = nla_attr_size(data_len);
581
582 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
583 goto nla_put_failure;
584
585 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
586 nla->nla_type = NFULA_PAYLOAD;
587 nla->nla_len = size;
588
589 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
590 BUG();
591 }
592
593 nlh->nlmsg_len = inst->skb->tail - old_tail;
594 return 0;
595
596 nla_put_failure:
597 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
598 return -1;
599 }
600
601 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
602
603 static struct nf_loginfo default_loginfo = {
604 .type = NF_LOG_TYPE_ULOG,
605 .u = {
606 .ulog = {
607 .copy_len = 0xffff,
608 .group = 0,
609 .qthreshold = 1,
610 },
611 },
612 };
613
614 /* log handler for internal netfilter logging api */
615 void
616 nfulnl_log_packet(struct net *net,
617 u_int8_t pf,
618 unsigned int hooknum,
619 const struct sk_buff *skb,
620 const struct net_device *in,
621 const struct net_device *out,
622 const struct nf_loginfo *li_user,
623 const char *prefix)
624 {
625 unsigned int size, data_len;
626 struct nfulnl_instance *inst;
627 const struct nf_loginfo *li;
628 unsigned int qthreshold;
629 unsigned int plen;
630 struct nfnl_log_net *log = nfnl_log_pernet(net);
631
632 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
633 li = li_user;
634 else
635 li = &default_loginfo;
636
637 inst = instance_lookup_get(log, li->u.ulog.group);
638 if (!inst)
639 return;
640
641 plen = 0;
642 if (prefix)
643 plen = strlen(prefix) + 1;
644
645 /* FIXME: do we want to make the size calculation conditional based on
646 * what is actually present? way more branches and checks, but more
647 * memory efficient... */
648 size = nlmsg_total_size(sizeof(struct nfgenmsg))
649 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
650 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
651 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
652 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
653 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
654 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
655 #endif
656 + nla_total_size(sizeof(u_int32_t)) /* mark */
657 + nla_total_size(sizeof(u_int32_t)) /* uid */
658 + nla_total_size(sizeof(u_int32_t)) /* gid */
659 + nla_total_size(plen) /* prefix */
660 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
661 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
662 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
663
664 if (in && skb_mac_header_was_set(skb)) {
665 size += nla_total_size(skb->dev->hard_header_len)
666 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
667 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
668 }
669
670 spin_lock_bh(&inst->lock);
671
672 if (inst->flags & NFULNL_CFG_F_SEQ)
673 size += nla_total_size(sizeof(u_int32_t));
674 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
675 size += nla_total_size(sizeof(u_int32_t));
676
677 qthreshold = inst->qthreshold;
678 /* per-rule qthreshold overrides per-instance */
679 if (li->u.ulog.qthreshold)
680 if (qthreshold > li->u.ulog.qthreshold)
681 qthreshold = li->u.ulog.qthreshold;
682
683
684 switch (inst->copy_mode) {
685 case NFULNL_COPY_META:
686 case NFULNL_COPY_NONE:
687 data_len = 0;
688 break;
689
690 case NFULNL_COPY_PACKET:
691 if (inst->copy_range > skb->len)
692 data_len = skb->len;
693 else
694 data_len = inst->copy_range;
695
696 size += nla_total_size(data_len);
697 break;
698
699 case NFULNL_COPY_DISABLED:
700 default:
701 goto unlock_and_release;
702 }
703
704 if (inst->skb && size > skb_tailroom(inst->skb)) {
705 /* either the queue len is too high or we don't have
706 * enough room in the skb left. flush to userspace. */
707 __nfulnl_flush(inst);
708 }
709
710 if (!inst->skb) {
711 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
712 inst->nlbufsiz, size);
713 if (!inst->skb)
714 goto alloc_failure;
715 }
716
717 inst->qlen++;
718
719 __build_packet_message(log, inst, skb, data_len, pf,
720 hooknum, in, out, prefix, plen);
721
722 if (inst->qlen >= qthreshold)
723 __nfulnl_flush(inst);
724 /* timer_pending always called within inst->lock, so there
725 * is no chance of a race here */
726 else if (!timer_pending(&inst->timer)) {
727 instance_get(inst);
728 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
729 add_timer(&inst->timer);
730 }
731
732 unlock_and_release:
733 spin_unlock_bh(&inst->lock);
734 instance_put(inst);
735 return;
736
737 alloc_failure:
738 /* FIXME: statistics */
739 goto unlock_and_release;
740 }
741 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
742
743 static int
744 nfulnl_rcv_nl_event(struct notifier_block *this,
745 unsigned long event, void *ptr)
746 {
747 struct netlink_notify *n = ptr;
748 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
749
750 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
751 int i;
752
753 /* destroy all instances for this portid */
754 spin_lock_bh(&log->instances_lock);
755 for (i = 0; i < INSTANCE_BUCKETS; i++) {
756 struct hlist_node *t2;
757 struct nfulnl_instance *inst;
758 struct hlist_head *head = &log->instance_table[i];
759
760 hlist_for_each_entry_safe(inst, t2, head, hlist) {
761 if (n->portid == inst->peer_portid)
762 __instance_destroy(inst);
763 }
764 }
765 spin_unlock_bh(&log->instances_lock);
766 }
767 return NOTIFY_DONE;
768 }
769
770 static struct notifier_block nfulnl_rtnl_notifier = {
771 .notifier_call = nfulnl_rcv_nl_event,
772 };
773
774 static int
775 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
776 const struct nlmsghdr *nlh,
777 const struct nlattr * const nfqa[])
778 {
779 return -ENOTSUPP;
780 }
781
782 static struct nf_logger nfulnl_logger __read_mostly = {
783 .name = "nfnetlink_log",
784 .type = NF_LOG_TYPE_ULOG,
785 .logfn = &nfulnl_log_packet,
786 .me = THIS_MODULE,
787 };
788
789 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
790 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
791 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
792 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
793 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
794 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
795 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
796 };
797
798 static int
799 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
800 const struct nlmsghdr *nlh,
801 const struct nlattr * const nfula[])
802 {
803 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
804 u_int16_t group_num = ntohs(nfmsg->res_id);
805 struct nfulnl_instance *inst;
806 struct nfulnl_msg_config_cmd *cmd = NULL;
807 struct net *net = sock_net(ctnl);
808 struct nfnl_log_net *log = nfnl_log_pernet(net);
809 int ret = 0;
810
811 if (nfula[NFULA_CFG_CMD]) {
812 u_int8_t pf = nfmsg->nfgen_family;
813 cmd = nla_data(nfula[NFULA_CFG_CMD]);
814
815 /* Commands without queue context */
816 switch (cmd->command) {
817 case NFULNL_CFG_CMD_PF_BIND:
818 return nf_log_bind_pf(net, pf, &nfulnl_logger);
819 case NFULNL_CFG_CMD_PF_UNBIND:
820 nf_log_unbind_pf(net, pf);
821 return 0;
822 }
823 }
824
825 inst = instance_lookup_get(log, group_num);
826 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
827 ret = -EPERM;
828 goto out_put;
829 }
830
831 if (cmd != NULL) {
832 switch (cmd->command) {
833 case NFULNL_CFG_CMD_BIND:
834 if (inst) {
835 ret = -EBUSY;
836 goto out_put;
837 }
838
839 inst = instance_create(net, group_num,
840 NETLINK_CB(skb).portid,
841 sk_user_ns(NETLINK_CB(skb).sk));
842 if (IS_ERR(inst)) {
843 ret = PTR_ERR(inst);
844 goto out;
845 }
846 break;
847 case NFULNL_CFG_CMD_UNBIND:
848 if (!inst) {
849 ret = -ENODEV;
850 goto out;
851 }
852
853 instance_destroy(log, inst);
854 goto out_put;
855 default:
856 ret = -ENOTSUPP;
857 break;
858 }
859 }
860
861 if (nfula[NFULA_CFG_MODE]) {
862 struct nfulnl_msg_config_mode *params;
863 params = nla_data(nfula[NFULA_CFG_MODE]);
864
865 if (!inst) {
866 ret = -ENODEV;
867 goto out;
868 }
869 nfulnl_set_mode(inst, params->copy_mode,
870 ntohl(params->copy_range));
871 }
872
873 if (nfula[NFULA_CFG_TIMEOUT]) {
874 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
875
876 if (!inst) {
877 ret = -ENODEV;
878 goto out;
879 }
880 nfulnl_set_timeout(inst, ntohl(timeout));
881 }
882
883 if (nfula[NFULA_CFG_NLBUFSIZ]) {
884 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
885
886 if (!inst) {
887 ret = -ENODEV;
888 goto out;
889 }
890 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
891 }
892
893 if (nfula[NFULA_CFG_QTHRESH]) {
894 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
895
896 if (!inst) {
897 ret = -ENODEV;
898 goto out;
899 }
900 nfulnl_set_qthresh(inst, ntohl(qthresh));
901 }
902
903 if (nfula[NFULA_CFG_FLAGS]) {
904 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
905
906 if (!inst) {
907 ret = -ENODEV;
908 goto out;
909 }
910 nfulnl_set_flags(inst, ntohs(flags));
911 }
912
913 out_put:
914 instance_put(inst);
915 out:
916 return ret;
917 }
918
919 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
920 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
921 .attr_count = NFULA_MAX, },
922 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
923 .attr_count = NFULA_CFG_MAX,
924 .policy = nfula_cfg_policy },
925 };
926
927 static const struct nfnetlink_subsystem nfulnl_subsys = {
928 .name = "log",
929 .subsys_id = NFNL_SUBSYS_ULOG,
930 .cb_count = NFULNL_MSG_MAX,
931 .cb = nfulnl_cb,
932 };
933
934 #ifdef CONFIG_PROC_FS
935 struct iter_state {
936 struct seq_net_private p;
937 unsigned int bucket;
938 };
939
940 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
941 {
942 struct nfnl_log_net *log;
943 if (!st)
944 return NULL;
945
946 log = nfnl_log_pernet(net);
947
948 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
949 struct hlist_head *head = &log->instance_table[st->bucket];
950
951 if (!hlist_empty(head))
952 return rcu_dereference_bh(hlist_first_rcu(head));
953 }
954 return NULL;
955 }
956
957 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
958 struct hlist_node *h)
959 {
960 h = rcu_dereference_bh(hlist_next_rcu(h));
961 while (!h) {
962 struct nfnl_log_net *log;
963 struct hlist_head *head;
964
965 if (++st->bucket >= INSTANCE_BUCKETS)
966 return NULL;
967
968 log = nfnl_log_pernet(net);
969 head = &log->instance_table[st->bucket];
970 h = rcu_dereference_bh(hlist_first_rcu(head));
971 }
972 return h;
973 }
974
975 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
976 loff_t pos)
977 {
978 struct hlist_node *head;
979 head = get_first(net, st);
980
981 if (head)
982 while (pos && (head = get_next(net, st, head)))
983 pos--;
984 return pos ? NULL : head;
985 }
986
987 static void *seq_start(struct seq_file *s, loff_t *pos)
988 __acquires(rcu_bh)
989 {
990 rcu_read_lock_bh();
991 return get_idx(seq_file_net(s), s->private, *pos);
992 }
993
994 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
995 {
996 (*pos)++;
997 return get_next(seq_file_net(s), s->private, v);
998 }
999
1000 static void seq_stop(struct seq_file *s, void *v)
1001 __releases(rcu_bh)
1002 {
1003 rcu_read_unlock_bh();
1004 }
1005
1006 static int seq_show(struct seq_file *s, void *v)
1007 {
1008 const struct nfulnl_instance *inst = v;
1009
1010 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1011 inst->group_num,
1012 inst->peer_portid, inst->qlen,
1013 inst->copy_mode, inst->copy_range,
1014 inst->flushtimeout, atomic_read(&inst->use));
1015
1016 return 0;
1017 }
1018
1019 static const struct seq_operations nful_seq_ops = {
1020 .start = seq_start,
1021 .next = seq_next,
1022 .stop = seq_stop,
1023 .show = seq_show,
1024 };
1025
1026 static int nful_open(struct inode *inode, struct file *file)
1027 {
1028 return seq_open_net(inode, file, &nful_seq_ops,
1029 sizeof(struct iter_state));
1030 }
1031
1032 static const struct file_operations nful_file_ops = {
1033 .owner = THIS_MODULE,
1034 .open = nful_open,
1035 .read = seq_read,
1036 .llseek = seq_lseek,
1037 .release = seq_release_net,
1038 };
1039
1040 #endif /* PROC_FS */
1041
1042 static int __net_init nfnl_log_net_init(struct net *net)
1043 {
1044 unsigned int i;
1045 struct nfnl_log_net *log = nfnl_log_pernet(net);
1046
1047 for (i = 0; i < INSTANCE_BUCKETS; i++)
1048 INIT_HLIST_HEAD(&log->instance_table[i]);
1049 spin_lock_init(&log->instances_lock);
1050
1051 #ifdef CONFIG_PROC_FS
1052 if (!proc_create("nfnetlink_log", 0440,
1053 net->nf.proc_netfilter, &nful_file_ops))
1054 return -ENOMEM;
1055 #endif
1056 return 0;
1057 }
1058
1059 static void __net_exit nfnl_log_net_exit(struct net *net)
1060 {
1061 #ifdef CONFIG_PROC_FS
1062 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1063 #endif
1064 nf_log_unset(net, &nfulnl_logger);
1065 }
1066
1067 static struct pernet_operations nfnl_log_net_ops = {
1068 .init = nfnl_log_net_init,
1069 .exit = nfnl_log_net_exit,
1070 .id = &nfnl_log_net_id,
1071 .size = sizeof(struct nfnl_log_net),
1072 };
1073
1074 static int __init nfnetlink_log_init(void)
1075 {
1076 int status;
1077
1078 status = register_pernet_subsys(&nfnl_log_net_ops);
1079 if (status < 0) {
1080 pr_err("failed to register pernet ops\n");
1081 goto out;
1082 }
1083
1084 netlink_register_notifier(&nfulnl_rtnl_notifier);
1085 status = nfnetlink_subsys_register(&nfulnl_subsys);
1086 if (status < 0) {
1087 pr_err("failed to create netlink socket\n");
1088 goto cleanup_netlink_notifier;
1089 }
1090
1091 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1092 if (status < 0) {
1093 pr_err("failed to register logger\n");
1094 goto cleanup_subsys;
1095 }
1096
1097 return status;
1098
1099 cleanup_subsys:
1100 nfnetlink_subsys_unregister(&nfulnl_subsys);
1101 cleanup_netlink_notifier:
1102 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1103 unregister_pernet_subsys(&nfnl_log_net_ops);
1104 out:
1105 return status;
1106 }
1107
1108 static void __exit nfnetlink_log_fini(void)
1109 {
1110 nf_log_unregister(&nfulnl_logger);
1111 nfnetlink_subsys_unregister(&nfulnl_subsys);
1112 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1113 unregister_pernet_subsys(&nfnl_log_net_ops);
1114 }
1115
1116 MODULE_DESCRIPTION("netfilter userspace logging");
1117 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1118 MODULE_LICENSE("GPL");
1119 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1120 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1121 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1122 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1123
1124 module_init(nfnetlink_log_init);
1125 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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