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Merge tag 'sound-3.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
[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 #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/slab.h>
32 #include <net/sock.h>
33 #include <net/netfilter/nf_log.h>
34 #include <net/netns/generic.h>
35 #include <net/netfilter/nfnetlink_log.h>
36
37 #include <linux/atomic.h>
38
39 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
40 #include "../bridge/br_private.h"
41 #endif
42
43 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
44 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
45 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
46 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
47
48 #define PRINTR(x, args...) do { if (net_ratelimit()) \
49 printk(x, ## args); } while (0);
50
51 struct nfulnl_instance {
52 struct hlist_node hlist; /* global list of instances */
53 spinlock_t lock;
54 atomic_t use; /* use count */
55
56 unsigned int qlen; /* number of nlmsgs in skb */
57 struct sk_buff *skb; /* pre-allocatd skb */
58 struct timer_list timer;
59 struct net *net;
60 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
61 int peer_portid; /* PORTID of the peer process */
62
63 /* configurable parameters */
64 unsigned int flushtimeout; /* timeout until queue flush */
65 unsigned int nlbufsiz; /* netlink buffer allocation size */
66 unsigned int qthreshold; /* threshold of the queue */
67 u_int32_t copy_range;
68 u_int32_t seq; /* instance-local sequential counter */
69 u_int16_t group_num; /* number of this queue */
70 u_int16_t flags;
71 u_int8_t copy_mode;
72 struct rcu_head rcu;
73 };
74
75 #define INSTANCE_BUCKETS 16
76
77 static int nfnl_log_net_id __read_mostly;
78
79 struct nfnl_log_net {
80 spinlock_t instances_lock;
81 struct hlist_head instance_table[INSTANCE_BUCKETS];
82 atomic_t global_seq;
83 };
84
85 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
86 {
87 return net_generic(net, nfnl_log_net_id);
88 }
89
90 static inline u_int8_t instance_hashfn(u_int16_t group_num)
91 {
92 return ((group_num & 0xff) % INSTANCE_BUCKETS);
93 }
94
95 static struct nfulnl_instance *
96 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
97 {
98 struct hlist_head *head;
99 struct nfulnl_instance *inst;
100
101 head = &log->instance_table[instance_hashfn(group_num)];
102 hlist_for_each_entry_rcu(inst, head, hlist) {
103 if (inst->group_num == group_num)
104 return inst;
105 }
106 return NULL;
107 }
108
109 static inline void
110 instance_get(struct nfulnl_instance *inst)
111 {
112 atomic_inc(&inst->use);
113 }
114
115 static struct nfulnl_instance *
116 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
117 {
118 struct nfulnl_instance *inst;
119
120 rcu_read_lock_bh();
121 inst = __instance_lookup(log, group_num);
122 if (inst && !atomic_inc_not_zero(&inst->use))
123 inst = NULL;
124 rcu_read_unlock_bh();
125
126 return inst;
127 }
128
129 static void nfulnl_instance_free_rcu(struct rcu_head *head)
130 {
131 struct nfulnl_instance *inst =
132 container_of(head, struct nfulnl_instance, rcu);
133
134 put_net(inst->net);
135 kfree(inst);
136 module_put(THIS_MODULE);
137 }
138
139 static void
140 instance_put(struct nfulnl_instance *inst)
141 {
142 if (inst && atomic_dec_and_test(&inst->use))
143 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
144 }
145
146 static void nfulnl_timer(unsigned long data);
147
148 static struct nfulnl_instance *
149 instance_create(struct net *net, u_int16_t group_num,
150 int portid, struct user_namespace *user_ns)
151 {
152 struct nfulnl_instance *inst;
153 struct nfnl_log_net *log = nfnl_log_pernet(net);
154 int err;
155
156 spin_lock_bh(&log->instances_lock);
157 if (__instance_lookup(log, group_num)) {
158 err = -EEXIST;
159 goto out_unlock;
160 }
161
162 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
163 if (!inst) {
164 err = -ENOMEM;
165 goto out_unlock;
166 }
167
168 if (!try_module_get(THIS_MODULE)) {
169 kfree(inst);
170 err = -EAGAIN;
171 goto out_unlock;
172 }
173
174 INIT_HLIST_NODE(&inst->hlist);
175 spin_lock_init(&inst->lock);
176 /* needs to be two, since we _put() after creation */
177 atomic_set(&inst->use, 2);
178
179 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
180
181 inst->net = get_net(net);
182 inst->peer_user_ns = user_ns;
183 inst->peer_portid = portid;
184 inst->group_num = group_num;
185
186 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
187 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
188 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
189 inst->copy_mode = NFULNL_COPY_PACKET;
190 inst->copy_range = NFULNL_COPY_RANGE_MAX;
191
192 hlist_add_head_rcu(&inst->hlist,
193 &log->instance_table[instance_hashfn(group_num)]);
194
195
196 spin_unlock_bh(&log->instances_lock);
197
198 return inst;
199
200 out_unlock:
201 spin_unlock_bh(&log->instances_lock);
202 return ERR_PTR(err);
203 }
204
205 static void __nfulnl_flush(struct nfulnl_instance *inst);
206
207 /* called with BH disabled */
208 static void
209 __instance_destroy(struct nfulnl_instance *inst)
210 {
211 /* first pull it out of the global list */
212 hlist_del_rcu(&inst->hlist);
213
214 /* then flush all pending packets from skb */
215
216 spin_lock(&inst->lock);
217
218 /* lockless readers wont be able to use us */
219 inst->copy_mode = NFULNL_COPY_DISABLED;
220
221 if (inst->skb)
222 __nfulnl_flush(inst);
223 spin_unlock(&inst->lock);
224
225 /* and finally put the refcount */
226 instance_put(inst);
227 }
228
229 static inline void
230 instance_destroy(struct nfnl_log_net *log,
231 struct nfulnl_instance *inst)
232 {
233 spin_lock_bh(&log->instances_lock);
234 __instance_destroy(inst);
235 spin_unlock_bh(&log->instances_lock);
236 }
237
238 static int
239 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
240 unsigned int range)
241 {
242 int status = 0;
243
244 spin_lock_bh(&inst->lock);
245
246 switch (mode) {
247 case NFULNL_COPY_NONE:
248 case NFULNL_COPY_META:
249 inst->copy_mode = mode;
250 inst->copy_range = 0;
251 break;
252
253 case NFULNL_COPY_PACKET:
254 inst->copy_mode = mode;
255 inst->copy_range = min_t(unsigned int,
256 range, NFULNL_COPY_RANGE_MAX);
257 break;
258
259 default:
260 status = -EINVAL;
261 break;
262 }
263
264 spin_unlock_bh(&inst->lock);
265
266 return status;
267 }
268
269 static int
270 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
271 {
272 int status;
273
274 spin_lock_bh(&inst->lock);
275 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
276 status = -ERANGE;
277 else if (nlbufsiz > 131072)
278 status = -ERANGE;
279 else {
280 inst->nlbufsiz = nlbufsiz;
281 status = 0;
282 }
283 spin_unlock_bh(&inst->lock);
284
285 return status;
286 }
287
288 static int
289 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
290 {
291 spin_lock_bh(&inst->lock);
292 inst->flushtimeout = timeout;
293 spin_unlock_bh(&inst->lock);
294
295 return 0;
296 }
297
298 static int
299 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
300 {
301 spin_lock_bh(&inst->lock);
302 inst->qthreshold = qthresh;
303 spin_unlock_bh(&inst->lock);
304
305 return 0;
306 }
307
308 static int
309 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
310 {
311 spin_lock_bh(&inst->lock);
312 inst->flags = flags;
313 spin_unlock_bh(&inst->lock);
314
315 return 0;
316 }
317
318 static struct sk_buff *
319 nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
320 unsigned int pkt_size)
321 {
322 struct sk_buff *skb;
323 unsigned int n;
324
325 /* alloc skb which should be big enough for a whole multipart
326 * message. WARNING: has to be <= 128k due to slab restrictions */
327
328 n = max(inst_size, pkt_size);
329 skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
330 if (!skb) {
331 if (n > pkt_size) {
332 /* try to allocate only as much as we need for current
333 * packet */
334
335 skb = nfnetlink_alloc_skb(net, pkt_size,
336 peer_portid, GFP_ATOMIC);
337 if (!skb)
338 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
339 pkt_size);
340 }
341 }
342
343 return skb;
344 }
345
346 static int
347 __nfulnl_send(struct nfulnl_instance *inst)
348 {
349 int status = -1;
350
351 if (inst->qlen > 1) {
352 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
353 NLMSG_DONE,
354 sizeof(struct nfgenmsg),
355 0);
356 if (!nlh)
357 goto out;
358 }
359 status = nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
360 MSG_DONTWAIT);
361
362 inst->qlen = 0;
363 inst->skb = NULL;
364 out:
365 return status;
366 }
367
368 static void
369 __nfulnl_flush(struct nfulnl_instance *inst)
370 {
371 /* timer holds a reference */
372 if (del_timer(&inst->timer))
373 instance_put(inst);
374 if (inst->skb)
375 __nfulnl_send(inst);
376 }
377
378 static void
379 nfulnl_timer(unsigned long data)
380 {
381 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
382
383 spin_lock_bh(&inst->lock);
384 if (inst->skb)
385 __nfulnl_send(inst);
386 spin_unlock_bh(&inst->lock);
387 instance_put(inst);
388 }
389
390 /* This is an inline function, we don't really care about a long
391 * list of arguments */
392 static inline int
393 __build_packet_message(struct nfnl_log_net *log,
394 struct nfulnl_instance *inst,
395 const struct sk_buff *skb,
396 unsigned int data_len,
397 u_int8_t pf,
398 unsigned int hooknum,
399 const struct net_device *indev,
400 const struct net_device *outdev,
401 const char *prefix, unsigned int plen)
402 {
403 struct nfulnl_msg_packet_hdr pmsg;
404 struct nlmsghdr *nlh;
405 struct nfgenmsg *nfmsg;
406 sk_buff_data_t old_tail = inst->skb->tail;
407 struct sock *sk;
408 const unsigned char *hwhdrp;
409
410 nlh = nlmsg_put(inst->skb, 0, 0,
411 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
412 sizeof(struct nfgenmsg), 0);
413 if (!nlh)
414 return -1;
415 nfmsg = nlmsg_data(nlh);
416 nfmsg->nfgen_family = pf;
417 nfmsg->version = NFNETLINK_V0;
418 nfmsg->res_id = htons(inst->group_num);
419
420 memset(&pmsg, 0, sizeof(pmsg));
421 pmsg.hw_protocol = skb->protocol;
422 pmsg.hook = hooknum;
423
424 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
425 goto nla_put_failure;
426
427 if (prefix &&
428 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
429 goto nla_put_failure;
430
431 if (indev) {
432 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
433 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
434 htonl(indev->ifindex)))
435 goto nla_put_failure;
436 #else
437 if (pf == PF_BRIDGE) {
438 /* Case 1: outdev is physical input device, we need to
439 * look for bridge group (when called from
440 * netfilter_bridge) */
441 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
442 htonl(indev->ifindex)) ||
443 /* this is the bridge group "brX" */
444 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
445 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
446 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
447 goto nla_put_failure;
448 } else {
449 /* Case 2: indev is bridge group, we need to look for
450 * physical device (when called from ipv4) */
451 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
452 htonl(indev->ifindex)))
453 goto nla_put_failure;
454 if (skb->nf_bridge && skb->nf_bridge->physindev &&
455 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
456 htonl(skb->nf_bridge->physindev->ifindex)))
457 goto nla_put_failure;
458 }
459 #endif
460 }
461
462 if (outdev) {
463 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
464 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
465 htonl(outdev->ifindex)))
466 goto nla_put_failure;
467 #else
468 if (pf == PF_BRIDGE) {
469 /* Case 1: outdev is physical output device, we need to
470 * look for bridge group (when called from
471 * netfilter_bridge) */
472 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
473 htonl(outdev->ifindex)) ||
474 /* this is the bridge group "brX" */
475 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
476 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
477 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
478 goto nla_put_failure;
479 } else {
480 /* Case 2: indev is a bridge group, we need to look
481 * for physical device (when called from ipv4) */
482 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
483 htonl(outdev->ifindex)))
484 goto nla_put_failure;
485 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
486 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
487 htonl(skb->nf_bridge->physoutdev->ifindex)))
488 goto nla_put_failure;
489 }
490 #endif
491 }
492
493 if (skb->mark &&
494 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
495 goto nla_put_failure;
496
497 if (indev && skb->dev &&
498 skb->mac_header != skb->network_header) {
499 struct nfulnl_msg_packet_hw phw;
500 int len;
501
502 memset(&phw, 0, sizeof(phw));
503 len = dev_parse_header(skb, phw.hw_addr);
504 if (len > 0) {
505 phw.hw_addrlen = htons(len);
506 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
507 goto nla_put_failure;
508 }
509 }
510
511 if (indev && skb_mac_header_was_set(skb)) {
512 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
513 nla_put_be16(inst->skb, NFULA_HWLEN,
514 htons(skb->dev->hard_header_len)))
515 goto nla_put_failure;
516
517 hwhdrp = skb_mac_header(skb);
518
519 if (skb->dev->type == ARPHRD_SIT)
520 hwhdrp -= ETH_HLEN;
521
522 if (hwhdrp >= skb->head &&
523 nla_put(inst->skb, NFULA_HWHEADER,
524 skb->dev->hard_header_len, hwhdrp))
525 goto nla_put_failure;
526 }
527
528 if (skb->tstamp.tv64) {
529 struct nfulnl_msg_packet_timestamp ts;
530 struct timeval tv = ktime_to_timeval(skb->tstamp);
531 ts.sec = cpu_to_be64(tv.tv_sec);
532 ts.usec = cpu_to_be64(tv.tv_usec);
533
534 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
535 goto nla_put_failure;
536 }
537
538 /* UID */
539 sk = skb->sk;
540 if (sk && sk->sk_state != TCP_TIME_WAIT) {
541 read_lock_bh(&sk->sk_callback_lock);
542 if (sk->sk_socket && sk->sk_socket->file) {
543 struct file *file = sk->sk_socket->file;
544 const struct cred *cred = file->f_cred;
545 struct user_namespace *user_ns = inst->peer_user_ns;
546 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
547 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
548 read_unlock_bh(&sk->sk_callback_lock);
549 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
550 nla_put_be32(inst->skb, NFULA_GID, gid))
551 goto nla_put_failure;
552 } else
553 read_unlock_bh(&sk->sk_callback_lock);
554 }
555
556 /* local sequence number */
557 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
558 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
559 goto nla_put_failure;
560
561 /* global sequence number */
562 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
563 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
564 htonl(atomic_inc_return(&log->global_seq))))
565 goto nla_put_failure;
566
567 if (data_len) {
568 struct nlattr *nla;
569 int size = nla_attr_size(data_len);
570
571 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
572 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
573 return -1;
574 }
575
576 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
577 nla->nla_type = NFULA_PAYLOAD;
578 nla->nla_len = size;
579
580 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
581 BUG();
582 }
583
584 nlh->nlmsg_len = inst->skb->tail - old_tail;
585 return 0;
586
587 nla_put_failure:
588 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
589 return -1;
590 }
591
592 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
593
594 static struct nf_loginfo default_loginfo = {
595 .type = NF_LOG_TYPE_ULOG,
596 .u = {
597 .ulog = {
598 .copy_len = 0xffff,
599 .group = 0,
600 .qthreshold = 1,
601 },
602 },
603 };
604
605 /* log handler for internal netfilter logging api */
606 void
607 nfulnl_log_packet(struct net *net,
608 u_int8_t pf,
609 unsigned int hooknum,
610 const struct sk_buff *skb,
611 const struct net_device *in,
612 const struct net_device *out,
613 const struct nf_loginfo *li_user,
614 const char *prefix)
615 {
616 unsigned int size, data_len;
617 struct nfulnl_instance *inst;
618 const struct nf_loginfo *li;
619 unsigned int qthreshold;
620 unsigned int plen;
621 struct nfnl_log_net *log = nfnl_log_pernet(net);
622
623 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
624 li = li_user;
625 else
626 li = &default_loginfo;
627
628 inst = instance_lookup_get(log, li->u.ulog.group);
629 if (!inst)
630 return;
631
632 plen = 0;
633 if (prefix)
634 plen = strlen(prefix) + 1;
635
636 /* FIXME: do we want to make the size calculation conditional based on
637 * what is actually present? way more branches and checks, but more
638 * memory efficient... */
639 size = nlmsg_total_size(sizeof(struct nfgenmsg))
640 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
641 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
642 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
643 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
644 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
645 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
646 #endif
647 + nla_total_size(sizeof(u_int32_t)) /* mark */
648 + nla_total_size(sizeof(u_int32_t)) /* uid */
649 + nla_total_size(sizeof(u_int32_t)) /* gid */
650 + nla_total_size(plen) /* prefix */
651 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
652 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
653
654 if (in && skb_mac_header_was_set(skb)) {
655 size += nla_total_size(skb->dev->hard_header_len)
656 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
657 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
658 }
659
660 spin_lock_bh(&inst->lock);
661
662 if (inst->flags & NFULNL_CFG_F_SEQ)
663 size += nla_total_size(sizeof(u_int32_t));
664 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
665 size += nla_total_size(sizeof(u_int32_t));
666
667 qthreshold = inst->qthreshold;
668 /* per-rule qthreshold overrides per-instance */
669 if (li->u.ulog.qthreshold)
670 if (qthreshold > li->u.ulog.qthreshold)
671 qthreshold = li->u.ulog.qthreshold;
672
673
674 switch (inst->copy_mode) {
675 case NFULNL_COPY_META:
676 case NFULNL_COPY_NONE:
677 data_len = 0;
678 break;
679
680 case NFULNL_COPY_PACKET:
681 if (inst->copy_range == 0
682 || inst->copy_range > skb->len)
683 data_len = skb->len;
684 else
685 data_len = inst->copy_range;
686
687 size += nla_total_size(data_len);
688 break;
689
690 case NFULNL_COPY_DISABLED:
691 default:
692 goto unlock_and_release;
693 }
694
695 if (inst->skb &&
696 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
697 /* either the queue len is too high or we don't have
698 * enough room in the skb left. flush to userspace. */
699 __nfulnl_flush(inst);
700 }
701
702 if (!inst->skb) {
703 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
704 inst->nlbufsiz, size);
705 if (!inst->skb)
706 goto alloc_failure;
707 }
708
709 inst->qlen++;
710
711 __build_packet_message(log, inst, skb, data_len, pf,
712 hooknum, in, out, prefix, plen);
713
714 if (inst->qlen >= qthreshold)
715 __nfulnl_flush(inst);
716 /* timer_pending always called within inst->lock, so there
717 * is no chance of a race here */
718 else if (!timer_pending(&inst->timer)) {
719 instance_get(inst);
720 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
721 add_timer(&inst->timer);
722 }
723
724 unlock_and_release:
725 spin_unlock_bh(&inst->lock);
726 instance_put(inst);
727 return;
728
729 alloc_failure:
730 /* FIXME: statistics */
731 goto unlock_and_release;
732 }
733 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
734
735 static int
736 nfulnl_rcv_nl_event(struct notifier_block *this,
737 unsigned long event, void *ptr)
738 {
739 struct netlink_notify *n = ptr;
740 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
741
742 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
743 int i;
744
745 /* destroy all instances for this portid */
746 spin_lock_bh(&log->instances_lock);
747 for (i = 0; i < INSTANCE_BUCKETS; i++) {
748 struct hlist_node *t2;
749 struct nfulnl_instance *inst;
750 struct hlist_head *head = &log->instance_table[i];
751
752 hlist_for_each_entry_safe(inst, t2, head, hlist) {
753 if (n->portid == inst->peer_portid)
754 __instance_destroy(inst);
755 }
756 }
757 spin_unlock_bh(&log->instances_lock);
758 }
759 return NOTIFY_DONE;
760 }
761
762 static struct notifier_block nfulnl_rtnl_notifier = {
763 .notifier_call = nfulnl_rcv_nl_event,
764 };
765
766 static int
767 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
768 const struct nlmsghdr *nlh,
769 const struct nlattr * const nfqa[])
770 {
771 return -ENOTSUPP;
772 }
773
774 static struct nf_logger nfulnl_logger __read_mostly = {
775 .name = "nfnetlink_log",
776 .type = NF_LOG_TYPE_ULOG,
777 .logfn = &nfulnl_log_packet,
778 .me = THIS_MODULE,
779 };
780
781 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
782 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
783 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
784 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
785 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
786 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
787 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
788 };
789
790 static int
791 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
792 const struct nlmsghdr *nlh,
793 const struct nlattr * const nfula[])
794 {
795 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
796 u_int16_t group_num = ntohs(nfmsg->res_id);
797 struct nfulnl_instance *inst;
798 struct nfulnl_msg_config_cmd *cmd = NULL;
799 struct net *net = sock_net(ctnl);
800 struct nfnl_log_net *log = nfnl_log_pernet(net);
801 int ret = 0;
802
803 if (nfula[NFULA_CFG_CMD]) {
804 u_int8_t pf = nfmsg->nfgen_family;
805 cmd = nla_data(nfula[NFULA_CFG_CMD]);
806
807 /* Commands without queue context */
808 switch (cmd->command) {
809 case NFULNL_CFG_CMD_PF_BIND:
810 return nf_log_bind_pf(net, pf, &nfulnl_logger);
811 case NFULNL_CFG_CMD_PF_UNBIND:
812 nf_log_unbind_pf(net, pf);
813 return 0;
814 }
815 }
816
817 inst = instance_lookup_get(log, group_num);
818 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
819 ret = -EPERM;
820 goto out_put;
821 }
822
823 if (cmd != NULL) {
824 switch (cmd->command) {
825 case NFULNL_CFG_CMD_BIND:
826 if (inst) {
827 ret = -EBUSY;
828 goto out_put;
829 }
830
831 inst = instance_create(net, group_num,
832 NETLINK_CB(skb).portid,
833 sk_user_ns(NETLINK_CB(skb).sk));
834 if (IS_ERR(inst)) {
835 ret = PTR_ERR(inst);
836 goto out;
837 }
838 break;
839 case NFULNL_CFG_CMD_UNBIND:
840 if (!inst) {
841 ret = -ENODEV;
842 goto out;
843 }
844
845 instance_destroy(log, inst);
846 goto out_put;
847 default:
848 ret = -ENOTSUPP;
849 break;
850 }
851 }
852
853 if (nfula[NFULA_CFG_MODE]) {
854 struct nfulnl_msg_config_mode *params;
855 params = nla_data(nfula[NFULA_CFG_MODE]);
856
857 if (!inst) {
858 ret = -ENODEV;
859 goto out;
860 }
861 nfulnl_set_mode(inst, params->copy_mode,
862 ntohl(params->copy_range));
863 }
864
865 if (nfula[NFULA_CFG_TIMEOUT]) {
866 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
867
868 if (!inst) {
869 ret = -ENODEV;
870 goto out;
871 }
872 nfulnl_set_timeout(inst, ntohl(timeout));
873 }
874
875 if (nfula[NFULA_CFG_NLBUFSIZ]) {
876 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
877
878 if (!inst) {
879 ret = -ENODEV;
880 goto out;
881 }
882 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
883 }
884
885 if (nfula[NFULA_CFG_QTHRESH]) {
886 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
887
888 if (!inst) {
889 ret = -ENODEV;
890 goto out;
891 }
892 nfulnl_set_qthresh(inst, ntohl(qthresh));
893 }
894
895 if (nfula[NFULA_CFG_FLAGS]) {
896 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
897
898 if (!inst) {
899 ret = -ENODEV;
900 goto out;
901 }
902 nfulnl_set_flags(inst, ntohs(flags));
903 }
904
905 out_put:
906 instance_put(inst);
907 out:
908 return ret;
909 }
910
911 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
912 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
913 .attr_count = NFULA_MAX, },
914 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
915 .attr_count = NFULA_CFG_MAX,
916 .policy = nfula_cfg_policy },
917 };
918
919 static const struct nfnetlink_subsystem nfulnl_subsys = {
920 .name = "log",
921 .subsys_id = NFNL_SUBSYS_ULOG,
922 .cb_count = NFULNL_MSG_MAX,
923 .cb = nfulnl_cb,
924 };
925
926 #ifdef CONFIG_PROC_FS
927 struct iter_state {
928 struct seq_net_private p;
929 unsigned int bucket;
930 };
931
932 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
933 {
934 struct nfnl_log_net *log;
935 if (!st)
936 return NULL;
937
938 log = nfnl_log_pernet(net);
939
940 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
941 struct hlist_head *head = &log->instance_table[st->bucket];
942
943 if (!hlist_empty(head))
944 return rcu_dereference_bh(hlist_first_rcu(head));
945 }
946 return NULL;
947 }
948
949 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
950 struct hlist_node *h)
951 {
952 h = rcu_dereference_bh(hlist_next_rcu(h));
953 while (!h) {
954 struct nfnl_log_net *log;
955 struct hlist_head *head;
956
957 if (++st->bucket >= INSTANCE_BUCKETS)
958 return NULL;
959
960 log = nfnl_log_pernet(net);
961 head = &log->instance_table[st->bucket];
962 h = rcu_dereference_bh(hlist_first_rcu(head));
963 }
964 return h;
965 }
966
967 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
968 loff_t pos)
969 {
970 struct hlist_node *head;
971 head = get_first(net, st);
972
973 if (head)
974 while (pos && (head = get_next(net, st, head)))
975 pos--;
976 return pos ? NULL : head;
977 }
978
979 static void *seq_start(struct seq_file *s, loff_t *pos)
980 __acquires(rcu_bh)
981 {
982 rcu_read_lock_bh();
983 return get_idx(seq_file_net(s), s->private, *pos);
984 }
985
986 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
987 {
988 (*pos)++;
989 return get_next(seq_file_net(s), s->private, v);
990 }
991
992 static void seq_stop(struct seq_file *s, void *v)
993 __releases(rcu_bh)
994 {
995 rcu_read_unlock_bh();
996 }
997
998 static int seq_show(struct seq_file *s, void *v)
999 {
1000 const struct nfulnl_instance *inst = v;
1001
1002 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
1003 inst->group_num,
1004 inst->peer_portid, inst->qlen,
1005 inst->copy_mode, inst->copy_range,
1006 inst->flushtimeout, atomic_read(&inst->use));
1007 }
1008
1009 static const struct seq_operations nful_seq_ops = {
1010 .start = seq_start,
1011 .next = seq_next,
1012 .stop = seq_stop,
1013 .show = seq_show,
1014 };
1015
1016 static int nful_open(struct inode *inode, struct file *file)
1017 {
1018 return seq_open_net(inode, file, &nful_seq_ops,
1019 sizeof(struct iter_state));
1020 }
1021
1022 static const struct file_operations nful_file_ops = {
1023 .owner = THIS_MODULE,
1024 .open = nful_open,
1025 .read = seq_read,
1026 .llseek = seq_lseek,
1027 .release = seq_release_net,
1028 };
1029
1030 #endif /* PROC_FS */
1031
1032 static int __net_init nfnl_log_net_init(struct net *net)
1033 {
1034 unsigned int i;
1035 struct nfnl_log_net *log = nfnl_log_pernet(net);
1036
1037 for (i = 0; i < INSTANCE_BUCKETS; i++)
1038 INIT_HLIST_HEAD(&log->instance_table[i]);
1039 spin_lock_init(&log->instances_lock);
1040
1041 #ifdef CONFIG_PROC_FS
1042 if (!proc_create("nfnetlink_log", 0440,
1043 net->nf.proc_netfilter, &nful_file_ops))
1044 return -ENOMEM;
1045 #endif
1046 return 0;
1047 }
1048
1049 static void __net_exit nfnl_log_net_exit(struct net *net)
1050 {
1051 #ifdef CONFIG_PROC_FS
1052 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1053 #endif
1054 nf_log_unset(net, &nfulnl_logger);
1055 }
1056
1057 static struct pernet_operations nfnl_log_net_ops = {
1058 .init = nfnl_log_net_init,
1059 .exit = nfnl_log_net_exit,
1060 .id = &nfnl_log_net_id,
1061 .size = sizeof(struct nfnl_log_net),
1062 };
1063
1064 static int __init nfnetlink_log_init(void)
1065 {
1066 int status = -ENOMEM;
1067
1068 netlink_register_notifier(&nfulnl_rtnl_notifier);
1069 status = nfnetlink_subsys_register(&nfulnl_subsys);
1070 if (status < 0) {
1071 pr_err("log: failed to create netlink socket\n");
1072 goto cleanup_netlink_notifier;
1073 }
1074
1075 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1076 if (status < 0) {
1077 pr_err("log: failed to register logger\n");
1078 goto cleanup_subsys;
1079 }
1080
1081 status = register_pernet_subsys(&nfnl_log_net_ops);
1082 if (status < 0) {
1083 pr_err("log: failed to register pernet ops\n");
1084 goto cleanup_logger;
1085 }
1086 return status;
1087
1088 cleanup_logger:
1089 nf_log_unregister(&nfulnl_logger);
1090 cleanup_subsys:
1091 nfnetlink_subsys_unregister(&nfulnl_subsys);
1092 cleanup_netlink_notifier:
1093 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1094 return status;
1095 }
1096
1097 static void __exit nfnetlink_log_fini(void)
1098 {
1099 unregister_pernet_subsys(&nfnl_log_net_ops);
1100 nf_log_unregister(&nfulnl_logger);
1101 nfnetlink_subsys_unregister(&nfulnl_subsys);
1102 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1103 }
1104
1105 MODULE_DESCRIPTION("netfilter userspace logging");
1106 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1107 MODULE_LICENSE("GPL");
1108 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1109 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1110 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1111 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1112
1113 module_init(nfnetlink_log_init);
1114 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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