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Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blobc684ba95dbb49447b0ddb2a7a1f27b54536a5a03
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/netfilter/nf_conntrack_common.h>
31 #include <linux/spinlock.h>
32 #include <linux/sysctl.h>
33 #include <linux/proc_fs.h>
34 #include <linux/security.h>
35 #include <linux/list.h>
36 #include <linux/slab.h>
37 #include <net/sock.h>
38 #include <net/netfilter/nf_log.h>
39 #include <net/netns/generic.h>
40 #include <net/netfilter/nfnetlink_log.h>
41
42 #include <linux/atomic.h>
43 #include <linux/refcount.h>
44
45
46 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
47 #include "../bridge/br_private.h"
48 #endif
49
50 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
51 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
52 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
53 /* max packet size is limited by 16-bit struct nfattr nfa_len field */
54 #define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
55
56 #define PRINTR(x, args...) do { if (net_ratelimit()) \
57 printk(x, ## args); } while (0);
58
59 struct nfulnl_instance {
60 struct hlist_node hlist; /* global list of instances */
61 spinlock_t lock;
62 refcount_t use; /* use count */
63
64 unsigned int qlen; /* number of nlmsgs in skb */
65 struct sk_buff *skb; /* pre-allocatd skb */
66 struct timer_list timer;
67 struct net *net;
68 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
69 u32 peer_portid; /* PORTID of the peer process */
70
71 /* configurable parameters */
72 unsigned int flushtimeout; /* timeout until queue flush */
73 unsigned int nlbufsiz; /* netlink buffer allocation size */
74 unsigned int qthreshold; /* threshold of the queue */
75 u_int32_t copy_range;
76 u_int32_t seq; /* instance-local sequential counter */
77 u_int16_t group_num; /* number of this queue */
78 u_int16_t flags;
79 u_int8_t copy_mode;
80 struct rcu_head rcu;
81 };
82
83 #define INSTANCE_BUCKETS 16
84
85 static unsigned int nfnl_log_net_id __read_mostly;
86
87 struct nfnl_log_net {
88 spinlock_t instances_lock;
89 struct hlist_head instance_table[INSTANCE_BUCKETS];
90 atomic_t global_seq;
91 };
92
93 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
94 {
95 return net_generic(net, nfnl_log_net_id);
96 }
97
98 static inline u_int8_t instance_hashfn(u_int16_t group_num)
99 {
100 return ((group_num & 0xff) % INSTANCE_BUCKETS);
101 }
102
103 static struct nfulnl_instance *
104 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
105 {
106 struct hlist_head *head;
107 struct nfulnl_instance *inst;
108
109 head = &log->instance_table[instance_hashfn(group_num)];
110 hlist_for_each_entry_rcu(inst, head, hlist) {
111 if (inst->group_num == group_num)
112 return inst;
113 }
114 return NULL;
115 }
116
117 static inline void
118 instance_get(struct nfulnl_instance *inst)
119 {
120 refcount_inc(&inst->use);
121 }
122
123 static struct nfulnl_instance *
124 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
125 {
126 struct nfulnl_instance *inst;
127
128 rcu_read_lock_bh();
129 inst = __instance_lookup(log, group_num);
130 if (inst && !refcount_inc_not_zero(&inst->use))
131 inst = NULL;
132 rcu_read_unlock_bh();
133
134 return inst;
135 }
136
137 static void nfulnl_instance_free_rcu(struct rcu_head *head)
138 {
139 struct nfulnl_instance *inst =
140 container_of(head, struct nfulnl_instance, rcu);
141
142 put_net(inst->net);
143 kfree(inst);
144 module_put(THIS_MODULE);
145 }
146
147 static void
148 instance_put(struct nfulnl_instance *inst)
149 {
150 if (inst && refcount_dec_and_test(&inst->use))
151 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
152 }
153
154 static void nfulnl_timer(unsigned long data);
155
156 static struct nfulnl_instance *
157 instance_create(struct net *net, u_int16_t group_num,
158 u32 portid, struct user_namespace *user_ns)
159 {
160 struct nfulnl_instance *inst;
161 struct nfnl_log_net *log = nfnl_log_pernet(net);
162 int err;
163
164 spin_lock_bh(&log->instances_lock);
165 if (__instance_lookup(log, group_num)) {
166 err = -EEXIST;
167 goto out_unlock;
168 }
169
170 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
171 if (!inst) {
172 err = -ENOMEM;
173 goto out_unlock;
174 }
175
176 if (!try_module_get(THIS_MODULE)) {
177 kfree(inst);
178 err = -EAGAIN;
179 goto out_unlock;
180 }
181
182 INIT_HLIST_NODE(&inst->hlist);
183 spin_lock_init(&inst->lock);
184 /* needs to be two, since we _put() after creation */
185 refcount_set(&inst->use, 2);
186
187 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
188
189 inst->net = get_net(net);
190 inst->peer_user_ns = user_ns;
191 inst->peer_portid = portid;
192 inst->group_num = group_num;
193
194 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
195 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
196 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
197 inst->copy_mode = NFULNL_COPY_PACKET;
198 inst->copy_range = NFULNL_COPY_RANGE_MAX;
199
200 hlist_add_head_rcu(&inst->hlist,
201 &log->instance_table[instance_hashfn(group_num)]);
202
203
204 spin_unlock_bh(&log->instances_lock);
205
206 return inst;
207
208 out_unlock:
209 spin_unlock_bh(&log->instances_lock);
210 return ERR_PTR(err);
211 }
212
213 static void __nfulnl_flush(struct nfulnl_instance *inst);
214
215 /* called with BH disabled */
216 static void
217 __instance_destroy(struct nfulnl_instance *inst)
218 {
219 /* first pull it out of the global list */
220 hlist_del_rcu(&inst->hlist);
221
222 /* then flush all pending packets from skb */
223
224 spin_lock(&inst->lock);
225
226 /* lockless readers wont be able to use us */
227 inst->copy_mode = NFULNL_COPY_DISABLED;
228
229 if (inst->skb)
230 __nfulnl_flush(inst);
231 spin_unlock(&inst->lock);
232
233 /* and finally put the refcount */
234 instance_put(inst);
235 }
236
237 static inline void
238 instance_destroy(struct nfnl_log_net *log,
239 struct nfulnl_instance *inst)
240 {
241 spin_lock_bh(&log->instances_lock);
242 __instance_destroy(inst);
243 spin_unlock_bh(&log->instances_lock);
244 }
245
246 static int
247 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
248 unsigned int range)
249 {
250 int status = 0;
251
252 spin_lock_bh(&inst->lock);
253
254 switch (mode) {
255 case NFULNL_COPY_NONE:
256 case NFULNL_COPY_META:
257 inst->copy_mode = mode;
258 inst->copy_range = 0;
259 break;
260
261 case NFULNL_COPY_PACKET:
262 inst->copy_mode = mode;
263 if (range == 0)
264 range = NFULNL_COPY_RANGE_MAX;
265 inst->copy_range = min_t(unsigned int,
266 range, NFULNL_COPY_RANGE_MAX);
267 break;
268
269 default:
270 status = -EINVAL;
271 break;
272 }
273
274 spin_unlock_bh(&inst->lock);
275
276 return status;
277 }
278
279 static int
280 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
281 {
282 int status;
283
284 spin_lock_bh(&inst->lock);
285 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
286 status = -ERANGE;
287 else if (nlbufsiz > 131072)
288 status = -ERANGE;
289 else {
290 inst->nlbufsiz = nlbufsiz;
291 status = 0;
292 }
293 spin_unlock_bh(&inst->lock);
294
295 return status;
296 }
297
298 static void
299 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
300 {
301 spin_lock_bh(&inst->lock);
302 inst->flushtimeout = timeout;
303 spin_unlock_bh(&inst->lock);
304 }
305
306 static void
307 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
308 {
309 spin_lock_bh(&inst->lock);
310 inst->qthreshold = qthresh;
311 spin_unlock_bh(&inst->lock);
312 }
313
314 static int
315 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
316 {
317 spin_lock_bh(&inst->lock);
318 inst->flags = flags;
319 spin_unlock_bh(&inst->lock);
320
321 return 0;
322 }
323
324 static struct sk_buff *
325 nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
326 unsigned int pkt_size)
327 {
328 struct sk_buff *skb;
329 unsigned int n;
330
331 /* alloc skb which should be big enough for a whole multipart
332 * message. WARNING: has to be <= 128k due to slab restrictions */
333
334 n = max(inst_size, pkt_size);
335 skb = alloc_skb(n, GFP_ATOMIC | __GFP_NOWARN);
336 if (!skb) {
337 if (n > pkt_size) {
338 /* try to allocate only as much as we need for current
339 * packet */
340
341 skb = alloc_skb(pkt_size, GFP_ATOMIC);
342 }
343 }
344
345 return skb;
346 }
347
348 static void
349 __nfulnl_send(struct nfulnl_instance *inst)
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 (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
357 inst->skb->len, skb_tailroom(inst->skb))) {
358 kfree_skb(inst->skb);
359 goto out;
360 }
361 }
362 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
363 MSG_DONTWAIT);
364 out:
365 inst->qlen = 0;
366 inst->skb = NULL;
367 }
368
369 static void
370 __nfulnl_flush(struct nfulnl_instance *inst)
371 {
372 /* timer holds a reference */
373 if (del_timer(&inst->timer))
374 instance_put(inst);
375 if (inst->skb)
376 __nfulnl_send(inst);
377 }
378
379 static void
380 nfulnl_timer(unsigned long data)
381 {
382 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
383
384 spin_lock_bh(&inst->lock);
385 if (inst->skb)
386 __nfulnl_send(inst);
387 spin_unlock_bh(&inst->lock);
388 instance_put(inst);
389 }
390
391 /* This is an inline function, we don't really care about a long
392 * list of arguments */
393 static inline int
394 __build_packet_message(struct nfnl_log_net *log,
395 struct nfulnl_instance *inst,
396 const struct sk_buff *skb,
397 unsigned int data_len,
398 u_int8_t pf,
399 unsigned int hooknum,
400 const struct net_device *indev,
401 const struct net_device *outdev,
402 const char *prefix, unsigned int plen,
403 const struct nfnl_ct_hook *nfnl_ct,
404 struct nf_conn *ct, enum ip_conntrack_info ctinfo)
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_msg_type(NFNL_SUBSYS_ULOG, 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_thresh or
448 * nf_log_packet.
449 */
450 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
451 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
452 goto nla_put_failure;
453 } else {
454 struct net_device *physindev;
455
456 /* Case 2: indev is bridge group, we need to look for
457 * physical device (when called from ipv4) */
458 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
459 htonl(indev->ifindex)))
460 goto nla_put_failure;
461
462 physindev = nf_bridge_get_physindev(skb);
463 if (physindev &&
464 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
465 htonl(physindev->ifindex)))
466 goto nla_put_failure;
467 }
468 #endif
469 }
470
471 if (outdev) {
472 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
473 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
474 htonl(outdev->ifindex)))
475 goto nla_put_failure;
476 #else
477 if (pf == PF_BRIDGE) {
478 /* Case 1: outdev is physical output device, we need to
479 * look for bridge group (when called from
480 * netfilter_bridge) */
481 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
482 htonl(outdev->ifindex)) ||
483 /* this is the bridge group "brX" */
484 /* rcu_read_lock()ed by nf_hook_thresh or
485 * nf_log_packet.
486 */
487 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
488 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
489 goto nla_put_failure;
490 } else {
491 struct net_device *physoutdev;
492
493 /* Case 2: indev is a bridge group, we need to look
494 * for physical device (when called from ipv4) */
495 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
496 htonl(outdev->ifindex)))
497 goto nla_put_failure;
498
499 physoutdev = nf_bridge_get_physoutdev(skb);
500 if (physoutdev &&
501 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
502 htonl(physoutdev->ifindex)))
503 goto nla_put_failure;
504 }
505 #endif
506 }
507
508 if (skb->mark &&
509 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
510 goto nla_put_failure;
511
512 if (indev && skb->dev &&
513 skb->mac_header != skb->network_header) {
514 struct nfulnl_msg_packet_hw phw;
515 int len;
516
517 memset(&phw, 0, sizeof(phw));
518 len = dev_parse_header(skb, phw.hw_addr);
519 if (len > 0) {
520 phw.hw_addrlen = htons(len);
521 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
522 goto nla_put_failure;
523 }
524 }
525
526 if (indev && skb_mac_header_was_set(skb)) {
527 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
528 nla_put_be16(inst->skb, NFULA_HWLEN,
529 htons(skb->dev->hard_header_len)))
530 goto nla_put_failure;
531
532 hwhdrp = skb_mac_header(skb);
533
534 if (skb->dev->type == ARPHRD_SIT)
535 hwhdrp -= ETH_HLEN;
536
537 if (hwhdrp >= skb->head &&
538 nla_put(inst->skb, NFULA_HWHEADER,
539 skb->dev->hard_header_len, hwhdrp))
540 goto nla_put_failure;
541 }
542
543 if (skb->tstamp) {
544 struct nfulnl_msg_packet_timestamp ts;
545 struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
546 ts.sec = cpu_to_be64(kts.tv_sec);
547 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
548
549 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
550 goto nla_put_failure;
551 }
552
553 /* UID */
554 sk = skb->sk;
555 if (sk && sk_fullsock(sk)) {
556 read_lock_bh(&sk->sk_callback_lock);
557 if (sk->sk_socket && sk->sk_socket->file) {
558 struct file *file = sk->sk_socket->file;
559 const struct cred *cred = file->f_cred;
560 struct user_namespace *user_ns = inst->peer_user_ns;
561 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
562 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
563 read_unlock_bh(&sk->sk_callback_lock);
564 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
565 nla_put_be32(inst->skb, NFULA_GID, gid))
566 goto nla_put_failure;
567 } else
568 read_unlock_bh(&sk->sk_callback_lock);
569 }
570
571 /* local sequence number */
572 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
573 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
574 goto nla_put_failure;
575
576 /* global sequence number */
577 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
578 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
579 htonl(atomic_inc_return(&log->global_seq))))
580 goto nla_put_failure;
581
582 if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
583 NFULA_CT, NFULA_CT_INFO) < 0)
584 goto nla_put_failure;
585
586 if (data_len) {
587 struct nlattr *nla;
588 int size = nla_attr_size(data_len);
589
590 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
591 goto nla_put_failure;
592
593 nla = skb_put(inst->skb, nla_total_size(data_len));
594 nla->nla_type = NFULA_PAYLOAD;
595 nla->nla_len = size;
596
597 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
598 BUG();
599 }
600
601 nlh->nlmsg_len = inst->skb->tail - old_tail;
602 return 0;
603
604 nla_put_failure:
605 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
606 return -1;
607 }
608
609 static struct nf_loginfo default_loginfo = {
610 .type = NF_LOG_TYPE_ULOG,
611 .u = {
612 .ulog = {
613 .copy_len = 0xffff,
614 .group = 0,
615 .qthreshold = 1,
616 },
617 },
618 };
619
620 /* log handler for internal netfilter logging api */
621 void
622 nfulnl_log_packet(struct net *net,
623 u_int8_t pf,
624 unsigned int hooknum,
625 const struct sk_buff *skb,
626 const struct net_device *in,
627 const struct net_device *out,
628 const struct nf_loginfo *li_user,
629 const char *prefix)
630 {
631 size_t size;
632 unsigned int data_len;
633 struct nfulnl_instance *inst;
634 const struct nf_loginfo *li;
635 unsigned int qthreshold;
636 unsigned int plen;
637 struct nfnl_log_net *log = nfnl_log_pernet(net);
638 const struct nfnl_ct_hook *nfnl_ct = NULL;
639 struct nf_conn *ct = NULL;
640 enum ip_conntrack_info uninitialized_var(ctinfo);
641
642 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
643 li = li_user;
644 else
645 li = &default_loginfo;
646
647 inst = instance_lookup_get(log, li->u.ulog.group);
648 if (!inst)
649 return;
650
651 plen = 0;
652 if (prefix)
653 plen = strlen(prefix) + 1;
654
655 /* FIXME: do we want to make the size calculation conditional based on
656 * what is actually present? way more branches and checks, but more
657 * memory efficient... */
658 size = nlmsg_total_size(sizeof(struct nfgenmsg))
659 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
660 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
661 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
662 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
663 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
664 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
665 #endif
666 + nla_total_size(sizeof(u_int32_t)) /* mark */
667 + nla_total_size(sizeof(u_int32_t)) /* uid */
668 + nla_total_size(sizeof(u_int32_t)) /* gid */
669 + nla_total_size(plen) /* prefix */
670 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
671 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
672 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
673
674 if (in && skb_mac_header_was_set(skb)) {
675 size += nla_total_size(skb->dev->hard_header_len)
676 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
677 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
678 }
679
680 spin_lock_bh(&inst->lock);
681
682 if (inst->flags & NFULNL_CFG_F_SEQ)
683 size += nla_total_size(sizeof(u_int32_t));
684 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
685 size += nla_total_size(sizeof(u_int32_t));
686 if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
687 nfnl_ct = rcu_dereference(nfnl_ct_hook);
688 if (nfnl_ct != NULL) {
689 ct = nfnl_ct->get_ct(skb, &ctinfo);
690 if (ct != NULL)
691 size += nfnl_ct->build_size(ct);
692 }
693 }
694
695 qthreshold = inst->qthreshold;
696 /* per-rule qthreshold overrides per-instance */
697 if (li->u.ulog.qthreshold)
698 if (qthreshold > li->u.ulog.qthreshold)
699 qthreshold = li->u.ulog.qthreshold;
700
701
702 switch (inst->copy_mode) {
703 case NFULNL_COPY_META:
704 case NFULNL_COPY_NONE:
705 data_len = 0;
706 break;
707
708 case NFULNL_COPY_PACKET:
709 data_len = inst->copy_range;
710 if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
711 (li->u.ulog.copy_len < data_len))
712 data_len = li->u.ulog.copy_len;
713
714 if (data_len > skb->len)
715 data_len = skb->len;
716
717 size += nla_total_size(data_len);
718 break;
719
720 case NFULNL_COPY_DISABLED:
721 default:
722 goto unlock_and_release;
723 }
724
725 if (inst->skb && size > skb_tailroom(inst->skb)) {
726 /* either the queue len is too high or we don't have
727 * enough room in the skb left. flush to userspace. */
728 __nfulnl_flush(inst);
729 }
730
731 if (!inst->skb) {
732 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
733 inst->nlbufsiz, size);
734 if (!inst->skb)
735 goto alloc_failure;
736 }
737
738 inst->qlen++;
739
740 __build_packet_message(log, inst, skb, data_len, pf,
741 hooknum, in, out, prefix, plen,
742 nfnl_ct, ct, ctinfo);
743
744 if (inst->qlen >= qthreshold)
745 __nfulnl_flush(inst);
746 /* timer_pending always called within inst->lock, so there
747 * is no chance of a race here */
748 else if (!timer_pending(&inst->timer)) {
749 instance_get(inst);
750 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
751 add_timer(&inst->timer);
752 }
753
754 unlock_and_release:
755 spin_unlock_bh(&inst->lock);
756 instance_put(inst);
757 return;
758
759 alloc_failure:
760 /* FIXME: statistics */
761 goto unlock_and_release;
762 }
763 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
764
765 static int
766 nfulnl_rcv_nl_event(struct notifier_block *this,
767 unsigned long event, void *ptr)
768 {
769 struct netlink_notify *n = ptr;
770 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
771
772 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
773 int i;
774
775 /* destroy all instances for this portid */
776 spin_lock_bh(&log->instances_lock);
777 for (i = 0; i < INSTANCE_BUCKETS; i++) {
778 struct hlist_node *t2;
779 struct nfulnl_instance *inst;
780 struct hlist_head *head = &log->instance_table[i];
781
782 hlist_for_each_entry_safe(inst, t2, head, hlist) {
783 if (n->portid == inst->peer_portid)
784 __instance_destroy(inst);
785 }
786 }
787 spin_unlock_bh(&log->instances_lock);
788 }
789 return NOTIFY_DONE;
790 }
791
792 static struct notifier_block nfulnl_rtnl_notifier = {
793 .notifier_call = nfulnl_rcv_nl_event,
794 };
795
796 static int nfulnl_recv_unsupp(struct net *net, struct sock *ctnl,
797 struct sk_buff *skb, const struct nlmsghdr *nlh,
798 const struct nlattr * const nfqa[],
799 struct netlink_ext_ack *extack)
800 {
801 return -ENOTSUPP;
802 }
803
804 static struct nf_logger nfulnl_logger __read_mostly = {
805 .name = "nfnetlink_log",
806 .type = NF_LOG_TYPE_ULOG,
807 .logfn = nfulnl_log_packet,
808 .me = THIS_MODULE,
809 };
810
811 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
812 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
813 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
814 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
815 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
816 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
817 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
818 };
819
820 static int nfulnl_recv_config(struct net *net, struct sock *ctnl,
821 struct sk_buff *skb, const struct nlmsghdr *nlh,
822 const struct nlattr * const nfula[],
823 struct netlink_ext_ack *extack)
824 {
825 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
826 u_int16_t group_num = ntohs(nfmsg->res_id);
827 struct nfulnl_instance *inst;
828 struct nfulnl_msg_config_cmd *cmd = NULL;
829 struct nfnl_log_net *log = nfnl_log_pernet(net);
830 int ret = 0;
831 u16 flags = 0;
832
833 if (nfula[NFULA_CFG_CMD]) {
834 u_int8_t pf = nfmsg->nfgen_family;
835 cmd = nla_data(nfula[NFULA_CFG_CMD]);
836
837 /* Commands without queue context */
838 switch (cmd->command) {
839 case NFULNL_CFG_CMD_PF_BIND:
840 return nf_log_bind_pf(net, pf, &nfulnl_logger);
841 case NFULNL_CFG_CMD_PF_UNBIND:
842 nf_log_unbind_pf(net, pf);
843 return 0;
844 }
845 }
846
847 inst = instance_lookup_get(log, group_num);
848 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
849 ret = -EPERM;
850 goto out_put;
851 }
852
853 /* Check if we support these flags in first place, dependencies should
854 * be there too not to break atomicity.
855 */
856 if (nfula[NFULA_CFG_FLAGS]) {
857 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
858
859 if ((flags & NFULNL_CFG_F_CONNTRACK) &&
860 !rcu_access_pointer(nfnl_ct_hook)) {
861 #ifdef CONFIG_MODULES
862 nfnl_unlock(NFNL_SUBSYS_ULOG);
863 request_module("ip_conntrack_netlink");
864 nfnl_lock(NFNL_SUBSYS_ULOG);
865 if (rcu_access_pointer(nfnl_ct_hook)) {
866 ret = -EAGAIN;
867 goto out_put;
868 }
869 #endif
870 ret = -EOPNOTSUPP;
871 goto out_put;
872 }
873 }
874
875 if (cmd != NULL) {
876 switch (cmd->command) {
877 case NFULNL_CFG_CMD_BIND:
878 if (inst) {
879 ret = -EBUSY;
880 goto out_put;
881 }
882
883 inst = instance_create(net, group_num,
884 NETLINK_CB(skb).portid,
885 sk_user_ns(NETLINK_CB(skb).sk));
886 if (IS_ERR(inst)) {
887 ret = PTR_ERR(inst);
888 goto out;
889 }
890 break;
891 case NFULNL_CFG_CMD_UNBIND:
892 if (!inst) {
893 ret = -ENODEV;
894 goto out;
895 }
896
897 instance_destroy(log, inst);
898 goto out_put;
899 default:
900 ret = -ENOTSUPP;
901 goto out_put;
902 }
903 } else if (!inst) {
904 ret = -ENODEV;
905 goto out;
906 }
907
908 if (nfula[NFULA_CFG_MODE]) {
909 struct nfulnl_msg_config_mode *params =
910 nla_data(nfula[NFULA_CFG_MODE]);
911
912 nfulnl_set_mode(inst, params->copy_mode,
913 ntohl(params->copy_range));
914 }
915
916 if (nfula[NFULA_CFG_TIMEOUT]) {
917 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
918
919 nfulnl_set_timeout(inst, ntohl(timeout));
920 }
921
922 if (nfula[NFULA_CFG_NLBUFSIZ]) {
923 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
924
925 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
926 }
927
928 if (nfula[NFULA_CFG_QTHRESH]) {
929 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
930
931 nfulnl_set_qthresh(inst, ntohl(qthresh));
932 }
933
934 if (nfula[NFULA_CFG_FLAGS])
935 nfulnl_set_flags(inst, flags);
936
937 out_put:
938 instance_put(inst);
939 out:
940 return ret;
941 }
942
943 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
944 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
945 .attr_count = NFULA_MAX, },
946 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
947 .attr_count = NFULA_CFG_MAX,
948 .policy = nfula_cfg_policy },
949 };
950
951 static const struct nfnetlink_subsystem nfulnl_subsys = {
952 .name = "log",
953 .subsys_id = NFNL_SUBSYS_ULOG,
954 .cb_count = NFULNL_MSG_MAX,
955 .cb = nfulnl_cb,
956 };
957
958 #ifdef CONFIG_PROC_FS
959 struct iter_state {
960 struct seq_net_private p;
961 unsigned int bucket;
962 };
963
964 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
965 {
966 struct nfnl_log_net *log;
967 if (!st)
968 return NULL;
969
970 log = nfnl_log_pernet(net);
971
972 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
973 struct hlist_head *head = &log->instance_table[st->bucket];
974
975 if (!hlist_empty(head))
976 return rcu_dereference_bh(hlist_first_rcu(head));
977 }
978 return NULL;
979 }
980
981 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
982 struct hlist_node *h)
983 {
984 h = rcu_dereference_bh(hlist_next_rcu(h));
985 while (!h) {
986 struct nfnl_log_net *log;
987 struct hlist_head *head;
988
989 if (++st->bucket >= INSTANCE_BUCKETS)
990 return NULL;
991
992 log = nfnl_log_pernet(net);
993 head = &log->instance_table[st->bucket];
994 h = rcu_dereference_bh(hlist_first_rcu(head));
995 }
996 return h;
997 }
998
999 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
1000 loff_t pos)
1001 {
1002 struct hlist_node *head;
1003 head = get_first(net, st);
1004
1005 if (head)
1006 while (pos && (head = get_next(net, st, head)))
1007 pos--;
1008 return pos ? NULL : head;
1009 }
1010
1011 static void *seq_start(struct seq_file *s, loff_t *pos)
1012 __acquires(rcu_bh)
1013 {
1014 rcu_read_lock_bh();
1015 return get_idx(seq_file_net(s), s->private, *pos);
1016 }
1017
1018 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1019 {
1020 (*pos)++;
1021 return get_next(seq_file_net(s), s->private, v);
1022 }
1023
1024 static void seq_stop(struct seq_file *s, void *v)
1025 __releases(rcu_bh)
1026 {
1027 rcu_read_unlock_bh();
1028 }
1029
1030 static int seq_show(struct seq_file *s, void *v)
1031 {
1032 const struct nfulnl_instance *inst = v;
1033
1034 seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
1035 inst->group_num,
1036 inst->peer_portid, inst->qlen,
1037 inst->copy_mode, inst->copy_range,
1038 inst->flushtimeout, refcount_read(&inst->use));
1039
1040 return 0;
1041 }
1042
1043 static const struct seq_operations nful_seq_ops = {
1044 .start = seq_start,
1045 .next = seq_next,
1046 .stop = seq_stop,
1047 .show = seq_show,
1048 };
1049
1050 static int nful_open(struct inode *inode, struct file *file)
1051 {
1052 return seq_open_net(inode, file, &nful_seq_ops,
1053 sizeof(struct iter_state));
1054 }
1055
1056 static const struct file_operations nful_file_ops = {
1057 .owner = THIS_MODULE,
1058 .open = nful_open,
1059 .read = seq_read,
1060 .llseek = seq_lseek,
1061 .release = seq_release_net,
1062 };
1063
1064 #endif /* PROC_FS */
1065
1066 static int __net_init nfnl_log_net_init(struct net *net)
1067 {
1068 unsigned int i;
1069 struct nfnl_log_net *log = nfnl_log_pernet(net);
1070 #ifdef CONFIG_PROC_FS
1071 struct proc_dir_entry *proc;
1072 kuid_t root_uid;
1073 kgid_t root_gid;
1074 #endif
1075
1076 for (i = 0; i < INSTANCE_BUCKETS; i++)
1077 INIT_HLIST_HEAD(&log->instance_table[i]);
1078 spin_lock_init(&log->instances_lock);
1079
1080 #ifdef CONFIG_PROC_FS
1081 proc = proc_create("nfnetlink_log", 0440,
1082 net->nf.proc_netfilter, &nful_file_ops);
1083 if (!proc)
1084 return -ENOMEM;
1085
1086 root_uid = make_kuid(net->user_ns, 0);
1087 root_gid = make_kgid(net->user_ns, 0);
1088 if (uid_valid(root_uid) && gid_valid(root_gid))
1089 proc_set_user(proc, root_uid, root_gid);
1090 #endif
1091 return 0;
1092 }
1093
1094 static void __net_exit nfnl_log_net_exit(struct net *net)
1095 {
1096 #ifdef CONFIG_PROC_FS
1097 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1098 #endif
1099 nf_log_unset(net, &nfulnl_logger);
1100 }
1101
1102 static struct pernet_operations nfnl_log_net_ops = {
1103 .init = nfnl_log_net_init,
1104 .exit = nfnl_log_net_exit,
1105 .id = &nfnl_log_net_id,
1106 .size = sizeof(struct nfnl_log_net),
1107 };
1108
1109 static int __init nfnetlink_log_init(void)
1110 {
1111 int status;
1112
1113 status = register_pernet_subsys(&nfnl_log_net_ops);
1114 if (status < 0) {
1115 pr_err("failed to register pernet ops\n");
1116 goto out;
1117 }
1118
1119 netlink_register_notifier(&nfulnl_rtnl_notifier);
1120 status = nfnetlink_subsys_register(&nfulnl_subsys);
1121 if (status < 0) {
1122 pr_err("failed to create netlink socket\n");
1123 goto cleanup_netlink_notifier;
1124 }
1125
1126 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1127 if (status < 0) {
1128 pr_err("failed to register logger\n");
1129 goto cleanup_subsys;
1130 }
1131
1132 return status;
1133
1134 cleanup_subsys:
1135 nfnetlink_subsys_unregister(&nfulnl_subsys);
1136 cleanup_netlink_notifier:
1137 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1138 unregister_pernet_subsys(&nfnl_log_net_ops);
1139 out:
1140 return status;
1141 }
1142
1143 static void __exit nfnetlink_log_fini(void)
1144 {
1145 nfnetlink_subsys_unregister(&nfulnl_subsys);
1146 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1147 unregister_pernet_subsys(&nfnl_log_net_ops);
1148 nf_log_unregister(&nfulnl_logger);
1149 }
1150
1151 MODULE_DESCRIPTION("netfilter userspace logging");
1152 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1153 MODULE_LICENSE("GPL");
1154 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1155 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1156 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1157 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1158 MODULE_ALIAS_NF_LOGGER(3, 1); /* NFPROTO_ARP */
1159 MODULE_ALIAS_NF_LOGGER(5, 1); /* NFPROTO_NETDEV */
1160
1161 module_init(nfnetlink_log_init);
1162 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support