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ARM: dts: add 'dr_mode' property to hsotg devices for exynos boards
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blob11d85b3813f26ae87f465d7f4d09ae36a6d0167e
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 <net/netlink.h>
27 #include <linux/netfilter/nfnetlink.h>
28 #include <linux/netfilter/nfnetlink_log.h>
29 #include <linux/spinlock.h>
30 #include <linux/sysctl.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/list.h>
34 #include <linux/slab.h>
35 #include <net/sock.h>
36 #include <net/netfilter/nf_log.h>
37 #include <net/netns/generic.h>
38 #include <net/netfilter/nfnetlink_log.h>
39
40 #include <linux/atomic.h>
41
42 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
43 #include "../bridge/br_private.h"
44 #endif
45
46 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
47 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
48 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
49 /* max packet size is limited by 16-bit struct nfattr nfa_len field */
50 #define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
51
52 #define PRINTR(x, args...) do { if (net_ratelimit()) \
53 printk(x, ## args); } while (0);
54
55 struct nfulnl_instance {
56 struct hlist_node hlist; /* global list of instances */
57 spinlock_t lock;
58 atomic_t use; /* use count */
59
60 unsigned int qlen; /* number of nlmsgs in skb */
61 struct sk_buff *skb; /* pre-allocatd skb */
62 struct timer_list timer;
63 struct net *net;
64 struct user_namespace *peer_user_ns; /* User namespace of the peer process */
65 int peer_portid; /* PORTID of the peer process */
66
67 /* configurable parameters */
68 unsigned int flushtimeout; /* timeout until queue flush */
69 unsigned int nlbufsiz; /* netlink buffer allocation size */
70 unsigned int qthreshold; /* threshold of the queue */
71 u_int32_t copy_range;
72 u_int32_t seq; /* instance-local sequential counter */
73 u_int16_t group_num; /* number of this queue */
74 u_int16_t flags;
75 u_int8_t copy_mode;
76 struct rcu_head rcu;
77 };
78
79 #define INSTANCE_BUCKETS 16
80
81 static int nfnl_log_net_id __read_mostly;
82
83 struct nfnl_log_net {
84 spinlock_t instances_lock;
85 struct hlist_head instance_table[INSTANCE_BUCKETS];
86 atomic_t global_seq;
87 };
88
89 static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
90 {
91 return net_generic(net, nfnl_log_net_id);
92 }
93
94 static inline u_int8_t instance_hashfn(u_int16_t group_num)
95 {
96 return ((group_num & 0xff) % INSTANCE_BUCKETS);
97 }
98
99 static struct nfulnl_instance *
100 __instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
101 {
102 struct hlist_head *head;
103 struct nfulnl_instance *inst;
104
105 head = &log->instance_table[instance_hashfn(group_num)];
106 hlist_for_each_entry_rcu(inst, head, hlist) {
107 if (inst->group_num == group_num)
108 return inst;
109 }
110 return NULL;
111 }
112
113 static inline void
114 instance_get(struct nfulnl_instance *inst)
115 {
116 atomic_inc(&inst->use);
117 }
118
119 static struct nfulnl_instance *
120 instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
121 {
122 struct nfulnl_instance *inst;
123
124 rcu_read_lock_bh();
125 inst = __instance_lookup(log, group_num);
126 if (inst && !atomic_inc_not_zero(&inst->use))
127 inst = NULL;
128 rcu_read_unlock_bh();
129
130 return inst;
131 }
132
133 static void nfulnl_instance_free_rcu(struct rcu_head *head)
134 {
135 struct nfulnl_instance *inst =
136 container_of(head, struct nfulnl_instance, rcu);
137
138 put_net(inst->net);
139 kfree(inst);
140 module_put(THIS_MODULE);
141 }
142
143 static void
144 instance_put(struct nfulnl_instance *inst)
145 {
146 if (inst && atomic_dec_and_test(&inst->use))
147 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
148 }
149
150 static void nfulnl_timer(unsigned long data);
151
152 static struct nfulnl_instance *
153 instance_create(struct net *net, u_int16_t group_num,
154 int portid, struct user_namespace *user_ns)
155 {
156 struct nfulnl_instance *inst;
157 struct nfnl_log_net *log = nfnl_log_pernet(net);
158 int err;
159
160 spin_lock_bh(&log->instances_lock);
161 if (__instance_lookup(log, group_num)) {
162 err = -EEXIST;
163 goto out_unlock;
164 }
165
166 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
167 if (!inst) {
168 err = -ENOMEM;
169 goto out_unlock;
170 }
171
172 if (!try_module_get(THIS_MODULE)) {
173 kfree(inst);
174 err = -EAGAIN;
175 goto out_unlock;
176 }
177
178 INIT_HLIST_NODE(&inst->hlist);
179 spin_lock_init(&inst->lock);
180 /* needs to be two, since we _put() after creation */
181 atomic_set(&inst->use, 2);
182
183 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
184
185 inst->net = get_net(net);
186 inst->peer_user_ns = user_ns;
187 inst->peer_portid = portid;
188 inst->group_num = group_num;
189
190 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
191 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
192 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
193 inst->copy_mode = NFULNL_COPY_PACKET;
194 inst->copy_range = NFULNL_COPY_RANGE_MAX;
195
196 hlist_add_head_rcu(&inst->hlist,
197 &log->instance_table[instance_hashfn(group_num)]);
198
199
200 spin_unlock_bh(&log->instances_lock);
201
202 return inst;
203
204 out_unlock:
205 spin_unlock_bh(&log->instances_lock);
206 return ERR_PTR(err);
207 }
208
209 static void __nfulnl_flush(struct nfulnl_instance *inst);
210
211 /* called with BH disabled */
212 static void
213 __instance_destroy(struct nfulnl_instance *inst)
214 {
215 /* first pull it out of the global list */
216 hlist_del_rcu(&inst->hlist);
217
218 /* then flush all pending packets from skb */
219
220 spin_lock(&inst->lock);
221
222 /* lockless readers wont be able to use us */
223 inst->copy_mode = NFULNL_COPY_DISABLED;
224
225 if (inst->skb)
226 __nfulnl_flush(inst);
227 spin_unlock(&inst->lock);
228
229 /* and finally put the refcount */
230 instance_put(inst);
231 }
232
233 static inline void
234 instance_destroy(struct nfnl_log_net *log,
235 struct nfulnl_instance *inst)
236 {
237 spin_lock_bh(&log->instances_lock);
238 __instance_destroy(inst);
239 spin_unlock_bh(&log->instances_lock);
240 }
241
242 static int
243 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
244 unsigned int range)
245 {
246 int status = 0;
247
248 spin_lock_bh(&inst->lock);
249
250 switch (mode) {
251 case NFULNL_COPY_NONE:
252 case NFULNL_COPY_META:
253 inst->copy_mode = mode;
254 inst->copy_range = 0;
255 break;
256
257 case NFULNL_COPY_PACKET:
258 inst->copy_mode = mode;
259 if (range == 0)
260 range = NFULNL_COPY_RANGE_MAX;
261 inst->copy_range = min_t(unsigned int,
262 range, NFULNL_COPY_RANGE_MAX);
263 break;
264
265 default:
266 status = -EINVAL;
267 break;
268 }
269
270 spin_unlock_bh(&inst->lock);
271
272 return status;
273 }
274
275 static int
276 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
277 {
278 int status;
279
280 spin_lock_bh(&inst->lock);
281 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
282 status = -ERANGE;
283 else if (nlbufsiz > 131072)
284 status = -ERANGE;
285 else {
286 inst->nlbufsiz = nlbufsiz;
287 status = 0;
288 }
289 spin_unlock_bh(&inst->lock);
290
291 return status;
292 }
293
294 static int
295 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
296 {
297 spin_lock_bh(&inst->lock);
298 inst->flushtimeout = timeout;
299 spin_unlock_bh(&inst->lock);
300
301 return 0;
302 }
303
304 static int
305 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
306 {
307 spin_lock_bh(&inst->lock);
308 inst->qthreshold = qthresh;
309 spin_unlock_bh(&inst->lock);
310
311 return 0;
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 = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
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 = nfnetlink_alloc_skb(net, pkt_size,
342 peer_portid, GFP_ATOMIC);
343 }
344 }
345
346 return skb;
347 }
348
349 static void
350 __nfulnl_send(struct nfulnl_instance *inst)
351 {
352 if (inst->qlen > 1) {
353 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
354 NLMSG_DONE,
355 sizeof(struct nfgenmsg),
356 0);
357 if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
358 inst->skb->len, skb_tailroom(inst->skb))) {
359 kfree_skb(inst->skb);
360 goto out;
361 }
362 }
363 nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
364 MSG_DONTWAIT);
365 out:
366 inst->qlen = 0;
367 inst->skb = NULL;
368 }
369
370 static void
371 __nfulnl_flush(struct nfulnl_instance *inst)
372 {
373 /* timer holds a reference */
374 if (del_timer(&inst->timer))
375 instance_put(inst);
376 if (inst->skb)
377 __nfulnl_send(inst);
378 }
379
380 static void
381 nfulnl_timer(unsigned long data)
382 {
383 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
384
385 spin_lock_bh(&inst->lock);
386 if (inst->skb)
387 __nfulnl_send(inst);
388 spin_unlock_bh(&inst->lock);
389 instance_put(inst);
390 }
391
392 /* This is an inline function, we don't really care about a long
393 * list of arguments */
394 static inline int
395 __build_packet_message(struct nfnl_log_net *log,
396 struct nfulnl_instance *inst,
397 const struct sk_buff *skb,
398 unsigned int data_len,
399 u_int8_t pf,
400 unsigned int hooknum,
401 const struct net_device *indev,
402 const struct net_device *outdev,
403 const char *prefix, unsigned int plen)
404 {
405 struct nfulnl_msg_packet_hdr pmsg;
406 struct nlmsghdr *nlh;
407 struct nfgenmsg *nfmsg;
408 sk_buff_data_t old_tail = inst->skb->tail;
409 struct sock *sk;
410 const unsigned char *hwhdrp;
411
412 nlh = nlmsg_put(inst->skb, 0, 0,
413 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
414 sizeof(struct nfgenmsg), 0);
415 if (!nlh)
416 return -1;
417 nfmsg = nlmsg_data(nlh);
418 nfmsg->nfgen_family = pf;
419 nfmsg->version = NFNETLINK_V0;
420 nfmsg->res_id = htons(inst->group_num);
421
422 memset(&pmsg, 0, sizeof(pmsg));
423 pmsg.hw_protocol = skb->protocol;
424 pmsg.hook = hooknum;
425
426 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
427 goto nla_put_failure;
428
429 if (prefix &&
430 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
431 goto nla_put_failure;
432
433 if (indev) {
434 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
435 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
436 htonl(indev->ifindex)))
437 goto nla_put_failure;
438 #else
439 if (pf == PF_BRIDGE) {
440 /* Case 1: outdev is physical input device, we need to
441 * look for bridge group (when called from
442 * netfilter_bridge) */
443 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
444 htonl(indev->ifindex)) ||
445 /* this is the bridge group "brX" */
446 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
447 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
448 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
449 goto nla_put_failure;
450 } else {
451 /* Case 2: indev is bridge group, we need to look for
452 * physical device (when called from ipv4) */
453 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
454 htonl(indev->ifindex)))
455 goto nla_put_failure;
456 if (skb->nf_bridge && skb->nf_bridge->physindev &&
457 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
458 htonl(skb->nf_bridge->physindev->ifindex)))
459 goto nla_put_failure;
460 }
461 #endif
462 }
463
464 if (outdev) {
465 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
466 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
467 htonl(outdev->ifindex)))
468 goto nla_put_failure;
469 #else
470 if (pf == PF_BRIDGE) {
471 /* Case 1: outdev is physical output device, we need to
472 * look for bridge group (when called from
473 * netfilter_bridge) */
474 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
475 htonl(outdev->ifindex)) ||
476 /* this is the bridge group "brX" */
477 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
478 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
479 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
480 goto nla_put_failure;
481 } else {
482 /* Case 2: indev is a bridge group, we need to look
483 * for physical device (when called from ipv4) */
484 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
485 htonl(outdev->ifindex)))
486 goto nla_put_failure;
487 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
488 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
489 htonl(skb->nf_bridge->physoutdev->ifindex)))
490 goto nla_put_failure;
491 }
492 #endif
493 }
494
495 if (skb->mark &&
496 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
497 goto nla_put_failure;
498
499 if (indev && skb->dev &&
500 skb->mac_header != skb->network_header) {
501 struct nfulnl_msg_packet_hw phw;
502 int len;
503
504 memset(&phw, 0, sizeof(phw));
505 len = dev_parse_header(skb, phw.hw_addr);
506 if (len > 0) {
507 phw.hw_addrlen = htons(len);
508 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
509 goto nla_put_failure;
510 }
511 }
512
513 if (indev && skb_mac_header_was_set(skb)) {
514 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
515 nla_put_be16(inst->skb, NFULA_HWLEN,
516 htons(skb->dev->hard_header_len)))
517 goto nla_put_failure;
518
519 hwhdrp = skb_mac_header(skb);
520
521 if (skb->dev->type == ARPHRD_SIT)
522 hwhdrp -= ETH_HLEN;
523
524 if (hwhdrp >= skb->head &&
525 nla_put(inst->skb, NFULA_HWHEADER,
526 skb->dev->hard_header_len, hwhdrp))
527 goto nla_put_failure;
528 }
529
530 if (skb->tstamp.tv64) {
531 struct nfulnl_msg_packet_timestamp ts;
532 struct timeval tv = ktime_to_timeval(skb->tstamp);
533 ts.sec = cpu_to_be64(tv.tv_sec);
534 ts.usec = cpu_to_be64(tv.tv_usec);
535
536 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
537 goto nla_put_failure;
538 }
539
540 /* UID */
541 sk = skb->sk;
542 if (sk && sk->sk_state != TCP_TIME_WAIT) {
543 read_lock_bh(&sk->sk_callback_lock);
544 if (sk->sk_socket && sk->sk_socket->file) {
545 struct file *file = sk->sk_socket->file;
546 const struct cred *cred = file->f_cred;
547 struct user_namespace *user_ns = inst->peer_user_ns;
548 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
549 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
550 read_unlock_bh(&sk->sk_callback_lock);
551 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
552 nla_put_be32(inst->skb, NFULA_GID, gid))
553 goto nla_put_failure;
554 } else
555 read_unlock_bh(&sk->sk_callback_lock);
556 }
557
558 /* local sequence number */
559 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
560 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
561 goto nla_put_failure;
562
563 /* global sequence number */
564 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
565 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
566 htonl(atomic_inc_return(&log->global_seq))))
567 goto nla_put_failure;
568
569 if (data_len) {
570 struct nlattr *nla;
571 int size = nla_attr_size(data_len);
572
573 if (skb_tailroom(inst->skb) < nla_total_size(data_len))
574 goto nla_put_failure;
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 + nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
654
655 if (in && skb_mac_header_was_set(skb)) {
656 size += nla_total_size(skb->dev->hard_header_len)
657 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
658 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
659 }
660
661 spin_lock_bh(&inst->lock);
662
663 if (inst->flags & NFULNL_CFG_F_SEQ)
664 size += nla_total_size(sizeof(u_int32_t));
665 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
666 size += nla_total_size(sizeof(u_int32_t));
667
668 qthreshold = inst->qthreshold;
669 /* per-rule qthreshold overrides per-instance */
670 if (li->u.ulog.qthreshold)
671 if (qthreshold > li->u.ulog.qthreshold)
672 qthreshold = li->u.ulog.qthreshold;
673
674
675 switch (inst->copy_mode) {
676 case NFULNL_COPY_META:
677 case NFULNL_COPY_NONE:
678 data_len = 0;
679 break;
680
681 case NFULNL_COPY_PACKET:
682 if (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 && size > skb_tailroom(inst->skb)) {
696 /* either the queue len is too high or we don't have
697 * enough room in the skb left. flush to userspace. */
698 __nfulnl_flush(inst);
699 }
700
701 if (!inst->skb) {
702 inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
703 inst->nlbufsiz, size);
704 if (!inst->skb)
705 goto alloc_failure;
706 }
707
708 inst->qlen++;
709
710 __build_packet_message(log, inst, skb, data_len, pf,
711 hooknum, in, out, prefix, plen);
712
713 if (inst->qlen >= qthreshold)
714 __nfulnl_flush(inst);
715 /* timer_pending always called within inst->lock, so there
716 * is no chance of a race here */
717 else if (!timer_pending(&inst->timer)) {
718 instance_get(inst);
719 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
720 add_timer(&inst->timer);
721 }
722
723 unlock_and_release:
724 spin_unlock_bh(&inst->lock);
725 instance_put(inst);
726 return;
727
728 alloc_failure:
729 /* FIXME: statistics */
730 goto unlock_and_release;
731 }
732 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
733
734 static int
735 nfulnl_rcv_nl_event(struct notifier_block *this,
736 unsigned long event, void *ptr)
737 {
738 struct netlink_notify *n = ptr;
739 struct nfnl_log_net *log = nfnl_log_pernet(n->net);
740
741 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
742 int i;
743
744 /* destroy all instances for this portid */
745 spin_lock_bh(&log->instances_lock);
746 for (i = 0; i < INSTANCE_BUCKETS; i++) {
747 struct hlist_node *t2;
748 struct nfulnl_instance *inst;
749 struct hlist_head *head = &log->instance_table[i];
750
751 hlist_for_each_entry_safe(inst, t2, head, hlist) {
752 if (n->portid == inst->peer_portid)
753 __instance_destroy(inst);
754 }
755 }
756 spin_unlock_bh(&log->instances_lock);
757 }
758 return NOTIFY_DONE;
759 }
760
761 static struct notifier_block nfulnl_rtnl_notifier = {
762 .notifier_call = nfulnl_rcv_nl_event,
763 };
764
765 static int
766 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
767 const struct nlmsghdr *nlh,
768 const struct nlattr * const nfqa[])
769 {
770 return -ENOTSUPP;
771 }
772
773 static struct nf_logger nfulnl_logger __read_mostly = {
774 .name = "nfnetlink_log",
775 .type = NF_LOG_TYPE_ULOG,
776 .logfn = &nfulnl_log_packet,
777 .me = THIS_MODULE,
778 };
779
780 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
781 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
782 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
783 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
784 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
785 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
786 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
787 };
788
789 static int
790 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
791 const struct nlmsghdr *nlh,
792 const struct nlattr * const nfula[])
793 {
794 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
795 u_int16_t group_num = ntohs(nfmsg->res_id);
796 struct nfulnl_instance *inst;
797 struct nfulnl_msg_config_cmd *cmd = NULL;
798 struct net *net = sock_net(ctnl);
799 struct nfnl_log_net *log = nfnl_log_pernet(net);
800 int ret = 0;
801
802 if (nfula[NFULA_CFG_CMD]) {
803 u_int8_t pf = nfmsg->nfgen_family;
804 cmd = nla_data(nfula[NFULA_CFG_CMD]);
805
806 /* Commands without queue context */
807 switch (cmd->command) {
808 case NFULNL_CFG_CMD_PF_BIND:
809 return nf_log_bind_pf(net, pf, &nfulnl_logger);
810 case NFULNL_CFG_CMD_PF_UNBIND:
811 nf_log_unbind_pf(net, pf);
812 return 0;
813 }
814 }
815
816 inst = instance_lookup_get(log, group_num);
817 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
818 ret = -EPERM;
819 goto out_put;
820 }
821
822 if (cmd != NULL) {
823 switch (cmd->command) {
824 case NFULNL_CFG_CMD_BIND:
825 if (inst) {
826 ret = -EBUSY;
827 goto out_put;
828 }
829
830 inst = instance_create(net, group_num,
831 NETLINK_CB(skb).portid,
832 sk_user_ns(NETLINK_CB(skb).sk));
833 if (IS_ERR(inst)) {
834 ret = PTR_ERR(inst);
835 goto out;
836 }
837 break;
838 case NFULNL_CFG_CMD_UNBIND:
839 if (!inst) {
840 ret = -ENODEV;
841 goto out;
842 }
843
844 instance_destroy(log, inst);
845 goto out_put;
846 default:
847 ret = -ENOTSUPP;
848 break;
849 }
850 }
851
852 if (nfula[NFULA_CFG_MODE]) {
853 struct nfulnl_msg_config_mode *params;
854 params = nla_data(nfula[NFULA_CFG_MODE]);
855
856 if (!inst) {
857 ret = -ENODEV;
858 goto out;
859 }
860 nfulnl_set_mode(inst, params->copy_mode,
861 ntohl(params->copy_range));
862 }
863
864 if (nfula[NFULA_CFG_TIMEOUT]) {
865 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
866
867 if (!inst) {
868 ret = -ENODEV;
869 goto out;
870 }
871 nfulnl_set_timeout(inst, ntohl(timeout));
872 }
873
874 if (nfula[NFULA_CFG_NLBUFSIZ]) {
875 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
876
877 if (!inst) {
878 ret = -ENODEV;
879 goto out;
880 }
881 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
882 }
883
884 if (nfula[NFULA_CFG_QTHRESH]) {
885 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
886
887 if (!inst) {
888 ret = -ENODEV;
889 goto out;
890 }
891 nfulnl_set_qthresh(inst, ntohl(qthresh));
892 }
893
894 if (nfula[NFULA_CFG_FLAGS]) {
895 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
896
897 if (!inst) {
898 ret = -ENODEV;
899 goto out;
900 }
901 nfulnl_set_flags(inst, ntohs(flags));
902 }
903
904 out_put:
905 instance_put(inst);
906 out:
907 return ret;
908 }
909
910 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
911 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
912 .attr_count = NFULA_MAX, },
913 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
914 .attr_count = NFULA_CFG_MAX,
915 .policy = nfula_cfg_policy },
916 };
917
918 static const struct nfnetlink_subsystem nfulnl_subsys = {
919 .name = "log",
920 .subsys_id = NFNL_SUBSYS_ULOG,
921 .cb_count = NFULNL_MSG_MAX,
922 .cb = nfulnl_cb,
923 };
924
925 #ifdef CONFIG_PROC_FS
926 struct iter_state {
927 struct seq_net_private p;
928 unsigned int bucket;
929 };
930
931 static struct hlist_node *get_first(struct net *net, struct iter_state *st)
932 {
933 struct nfnl_log_net *log;
934 if (!st)
935 return NULL;
936
937 log = nfnl_log_pernet(net);
938
939 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
940 struct hlist_head *head = &log->instance_table[st->bucket];
941
942 if (!hlist_empty(head))
943 return rcu_dereference_bh(hlist_first_rcu(head));
944 }
945 return NULL;
946 }
947
948 static struct hlist_node *get_next(struct net *net, struct iter_state *st,
949 struct hlist_node *h)
950 {
951 h = rcu_dereference_bh(hlist_next_rcu(h));
952 while (!h) {
953 struct nfnl_log_net *log;
954 struct hlist_head *head;
955
956 if (++st->bucket >= INSTANCE_BUCKETS)
957 return NULL;
958
959 log = nfnl_log_pernet(net);
960 head = &log->instance_table[st->bucket];
961 h = rcu_dereference_bh(hlist_first_rcu(head));
962 }
963 return h;
964 }
965
966 static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
967 loff_t pos)
968 {
969 struct hlist_node *head;
970 head = get_first(net, st);
971
972 if (head)
973 while (pos && (head = get_next(net, st, head)))
974 pos--;
975 return pos ? NULL : head;
976 }
977
978 static void *seq_start(struct seq_file *s, loff_t *pos)
979 __acquires(rcu_bh)
980 {
981 rcu_read_lock_bh();
982 return get_idx(seq_file_net(s), s->private, *pos);
983 }
984
985 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
986 {
987 (*pos)++;
988 return get_next(seq_file_net(s), s->private, v);
989 }
990
991 static void seq_stop(struct seq_file *s, void *v)
992 __releases(rcu_bh)
993 {
994 rcu_read_unlock_bh();
995 }
996
997 static int seq_show(struct seq_file *s, void *v)
998 {
999 const struct nfulnl_instance *inst = v;
1000
1001 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
1002 inst->group_num,
1003 inst->peer_portid, inst->qlen,
1004 inst->copy_mode, inst->copy_range,
1005 inst->flushtimeout, atomic_read(&inst->use));
1006 }
1007
1008 static const struct seq_operations nful_seq_ops = {
1009 .start = seq_start,
1010 .next = seq_next,
1011 .stop = seq_stop,
1012 .show = seq_show,
1013 };
1014
1015 static int nful_open(struct inode *inode, struct file *file)
1016 {
1017 return seq_open_net(inode, file, &nful_seq_ops,
1018 sizeof(struct iter_state));
1019 }
1020
1021 static const struct file_operations nful_file_ops = {
1022 .owner = THIS_MODULE,
1023 .open = nful_open,
1024 .read = seq_read,
1025 .llseek = seq_lseek,
1026 .release = seq_release_net,
1027 };
1028
1029 #endif /* PROC_FS */
1030
1031 static int __net_init nfnl_log_net_init(struct net *net)
1032 {
1033 unsigned int i;
1034 struct nfnl_log_net *log = nfnl_log_pernet(net);
1035
1036 for (i = 0; i < INSTANCE_BUCKETS; i++)
1037 INIT_HLIST_HEAD(&log->instance_table[i]);
1038 spin_lock_init(&log->instances_lock);
1039
1040 #ifdef CONFIG_PROC_FS
1041 if (!proc_create("nfnetlink_log", 0440,
1042 net->nf.proc_netfilter, &nful_file_ops))
1043 return -ENOMEM;
1044 #endif
1045 return 0;
1046 }
1047
1048 static void __net_exit nfnl_log_net_exit(struct net *net)
1049 {
1050 #ifdef CONFIG_PROC_FS
1051 remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
1052 #endif
1053 nf_log_unset(net, &nfulnl_logger);
1054 }
1055
1056 static struct pernet_operations nfnl_log_net_ops = {
1057 .init = nfnl_log_net_init,
1058 .exit = nfnl_log_net_exit,
1059 .id = &nfnl_log_net_id,
1060 .size = sizeof(struct nfnl_log_net),
1061 };
1062
1063 static int __init nfnetlink_log_init(void)
1064 {
1065 int status = -ENOMEM;
1066
1067 netlink_register_notifier(&nfulnl_rtnl_notifier);
1068 status = nfnetlink_subsys_register(&nfulnl_subsys);
1069 if (status < 0) {
1070 pr_err("failed to create netlink socket\n");
1071 goto cleanup_netlink_notifier;
1072 }
1073
1074 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1075 if (status < 0) {
1076 pr_err("failed to register logger\n");
1077 goto cleanup_subsys;
1078 }
1079
1080 status = register_pernet_subsys(&nfnl_log_net_ops);
1081 if (status < 0) {
1082 pr_err("failed to register pernet ops\n");
1083 goto cleanup_logger;
1084 }
1085 return status;
1086
1087 cleanup_logger:
1088 nf_log_unregister(&nfulnl_logger);
1089 cleanup_subsys:
1090 nfnetlink_subsys_unregister(&nfulnl_subsys);
1091 cleanup_netlink_notifier:
1092 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1093 return status;
1094 }
1095
1096 static void __exit nfnetlink_log_fini(void)
1097 {
1098 unregister_pernet_subsys(&nfnl_log_net_ops);
1099 nf_log_unregister(&nfulnl_logger);
1100 nfnetlink_subsys_unregister(&nfulnl_subsys);
1101 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1102 }
1103
1104 MODULE_DESCRIPTION("netfilter userspace logging");
1105 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1106 MODULE_LICENSE("GPL");
1107 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1108 MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
1109 MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
1110 MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
1111
1112 module_init(nfnetlink_log_init);
1113 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support