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mqueue: sys_mq_open: do not call mnt_drop_write() if read-only
[linux-2.6/cjktty.git] / net / netfilter / nfnetlink_log.c
blobf248db572972f71c3a40431e31fc1201eee5b78c
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 *
7 * Based on the old ipv4-only ipt_ULOG.c:
8 * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/if_arp.h>
17 #include <linux/init.h>
18 #include <linux/ip.h>
19 #include <linux/ipv6.h>
20 #include <linux/netdevice.h>
21 #include <linux/netfilter.h>
22 #include <linux/netlink.h>
23 #include <linux/netfilter/nfnetlink.h>
24 #include <linux/netfilter/nfnetlink_log.h>
25 #include <linux/spinlock.h>
26 #include <linux/sysctl.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/list.h>
30 #include <linux/jhash.h>
31 #include <linux/random.h>
32 #include <linux/slab.h>
33 #include <net/sock.h>
34 #include <net/netfilter/nf_log.h>
35 #include <net/netfilter/nfnetlink_log.h>
36
37 #include <linux/atomic.h>
38
39 #ifdef 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 user_namespace *peer_user_ns; /* User namespace of the peer process */
60 int peer_portid; /* PORTID of the peer process */
61
62 /* configurable parameters */
63 unsigned int flushtimeout; /* timeout until queue flush */
64 unsigned int nlbufsiz; /* netlink buffer allocation size */
65 unsigned int qthreshold; /* threshold of the queue */
66 u_int32_t copy_range;
67 u_int32_t seq; /* instance-local sequential counter */
68 u_int16_t group_num; /* number of this queue */
69 u_int16_t flags;
70 u_int8_t copy_mode;
71 struct rcu_head rcu;
72 };
73
74 static DEFINE_SPINLOCK(instances_lock);
75 static atomic_t global_seq;
76
77 #define INSTANCE_BUCKETS 16
78 static struct hlist_head instance_table[INSTANCE_BUCKETS];
79 static unsigned int hash_init;
80
81 static inline u_int8_t instance_hashfn(u_int16_t group_num)
82 {
83 return ((group_num & 0xff) % INSTANCE_BUCKETS);
84 }
85
86 static struct nfulnl_instance *
87 __instance_lookup(u_int16_t group_num)
88 {
89 struct hlist_head *head;
90 struct nfulnl_instance *inst;
91
92 head = &instance_table[instance_hashfn(group_num)];
93 hlist_for_each_entry_rcu(inst, head, hlist) {
94 if (inst->group_num == group_num)
95 return inst;
96 }
97 return NULL;
98 }
99
100 static inline void
101 instance_get(struct nfulnl_instance *inst)
102 {
103 atomic_inc(&inst->use);
104 }
105
106 static struct nfulnl_instance *
107 instance_lookup_get(u_int16_t group_num)
108 {
109 struct nfulnl_instance *inst;
110
111 rcu_read_lock_bh();
112 inst = __instance_lookup(group_num);
113 if (inst && !atomic_inc_not_zero(&inst->use))
114 inst = NULL;
115 rcu_read_unlock_bh();
116
117 return inst;
118 }
119
120 static void nfulnl_instance_free_rcu(struct rcu_head *head)
121 {
122 kfree(container_of(head, struct nfulnl_instance, rcu));
123 module_put(THIS_MODULE);
124 }
125
126 static void
127 instance_put(struct nfulnl_instance *inst)
128 {
129 if (inst && atomic_dec_and_test(&inst->use))
130 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
131 }
132
133 static void nfulnl_timer(unsigned long data);
134
135 static struct nfulnl_instance *
136 instance_create(u_int16_t group_num, int portid, struct user_namespace *user_ns)
137 {
138 struct nfulnl_instance *inst;
139 int err;
140
141 spin_lock_bh(&instances_lock);
142 if (__instance_lookup(group_num)) {
143 err = -EEXIST;
144 goto out_unlock;
145 }
146
147 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
148 if (!inst) {
149 err = -ENOMEM;
150 goto out_unlock;
151 }
152
153 if (!try_module_get(THIS_MODULE)) {
154 kfree(inst);
155 err = -EAGAIN;
156 goto out_unlock;
157 }
158
159 INIT_HLIST_NODE(&inst->hlist);
160 spin_lock_init(&inst->lock);
161 /* needs to be two, since we _put() after creation */
162 atomic_set(&inst->use, 2);
163
164 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
165
166 inst->peer_user_ns = user_ns;
167 inst->peer_portid = portid;
168 inst->group_num = group_num;
169
170 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
171 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
172 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
173 inst->copy_mode = NFULNL_COPY_PACKET;
174 inst->copy_range = NFULNL_COPY_RANGE_MAX;
175
176 hlist_add_head_rcu(&inst->hlist,
177 &instance_table[instance_hashfn(group_num)]);
178
179 spin_unlock_bh(&instances_lock);
180
181 return inst;
182
183 out_unlock:
184 spin_unlock_bh(&instances_lock);
185 return ERR_PTR(err);
186 }
187
188 static void __nfulnl_flush(struct nfulnl_instance *inst);
189
190 /* called with BH disabled */
191 static void
192 __instance_destroy(struct nfulnl_instance *inst)
193 {
194 /* first pull it out of the global list */
195 hlist_del_rcu(&inst->hlist);
196
197 /* then flush all pending packets from skb */
198
199 spin_lock(&inst->lock);
200
201 /* lockless readers wont be able to use us */
202 inst->copy_mode = NFULNL_COPY_DISABLED;
203
204 if (inst->skb)
205 __nfulnl_flush(inst);
206 spin_unlock(&inst->lock);
207
208 /* and finally put the refcount */
209 instance_put(inst);
210 }
211
212 static inline void
213 instance_destroy(struct nfulnl_instance *inst)
214 {
215 spin_lock_bh(&instances_lock);
216 __instance_destroy(inst);
217 spin_unlock_bh(&instances_lock);
218 }
219
220 static int
221 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
222 unsigned int range)
223 {
224 int status = 0;
225
226 spin_lock_bh(&inst->lock);
227
228 switch (mode) {
229 case NFULNL_COPY_NONE:
230 case NFULNL_COPY_META:
231 inst->copy_mode = mode;
232 inst->copy_range = 0;
233 break;
234
235 case NFULNL_COPY_PACKET:
236 inst->copy_mode = mode;
237 inst->copy_range = min_t(unsigned int,
238 range, NFULNL_COPY_RANGE_MAX);
239 break;
240
241 default:
242 status = -EINVAL;
243 break;
244 }
245
246 spin_unlock_bh(&inst->lock);
247
248 return status;
249 }
250
251 static int
252 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
253 {
254 int status;
255
256 spin_lock_bh(&inst->lock);
257 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
258 status = -ERANGE;
259 else if (nlbufsiz > 131072)
260 status = -ERANGE;
261 else {
262 inst->nlbufsiz = nlbufsiz;
263 status = 0;
264 }
265 spin_unlock_bh(&inst->lock);
266
267 return status;
268 }
269
270 static int
271 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
272 {
273 spin_lock_bh(&inst->lock);
274 inst->flushtimeout = timeout;
275 spin_unlock_bh(&inst->lock);
276
277 return 0;
278 }
279
280 static int
281 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
282 {
283 spin_lock_bh(&inst->lock);
284 inst->qthreshold = qthresh;
285 spin_unlock_bh(&inst->lock);
286
287 return 0;
288 }
289
290 static int
291 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
292 {
293 spin_lock_bh(&inst->lock);
294 inst->flags = flags;
295 spin_unlock_bh(&inst->lock);
296
297 return 0;
298 }
299
300 static struct sk_buff *
301 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
302 {
303 struct sk_buff *skb;
304 unsigned int n;
305
306 /* alloc skb which should be big enough for a whole multipart
307 * message. WARNING: has to be <= 128k due to slab restrictions */
308
309 n = max(inst_size, pkt_size);
310 skb = alloc_skb(n, GFP_ATOMIC);
311 if (!skb) {
312 if (n > pkt_size) {
313 /* try to allocate only as much as we need for current
314 * packet */
315
316 skb = alloc_skb(pkt_size, GFP_ATOMIC);
317 if (!skb)
318 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
319 pkt_size);
320 }
321 }
322
323 return skb;
324 }
325
326 static int
327 __nfulnl_send(struct nfulnl_instance *inst)
328 {
329 int status = -1;
330
331 if (inst->qlen > 1) {
332 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
333 NLMSG_DONE,
334 sizeof(struct nfgenmsg),
335 0);
336 if (!nlh)
337 goto out;
338 }
339 status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_portid,
340 MSG_DONTWAIT);
341
342 inst->qlen = 0;
343 inst->skb = NULL;
344 out:
345 return status;
346 }
347
348 static void
349 __nfulnl_flush(struct nfulnl_instance *inst)
350 {
351 /* timer holds a reference */
352 if (del_timer(&inst->timer))
353 instance_put(inst);
354 if (inst->skb)
355 __nfulnl_send(inst);
356 }
357
358 static void
359 nfulnl_timer(unsigned long data)
360 {
361 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
362
363 spin_lock_bh(&inst->lock);
364 if (inst->skb)
365 __nfulnl_send(inst);
366 spin_unlock_bh(&inst->lock);
367 instance_put(inst);
368 }
369
370 /* This is an inline function, we don't really care about a long
371 * list of arguments */
372 static inline int
373 __build_packet_message(struct nfulnl_instance *inst,
374 const struct sk_buff *skb,
375 unsigned int data_len,
376 u_int8_t pf,
377 unsigned int hooknum,
378 const struct net_device *indev,
379 const struct net_device *outdev,
380 const char *prefix, unsigned int plen)
381 {
382 struct nfulnl_msg_packet_hdr pmsg;
383 struct nlmsghdr *nlh;
384 struct nfgenmsg *nfmsg;
385 sk_buff_data_t old_tail = inst->skb->tail;
386 struct sock *sk;
387 const unsigned char *hwhdrp;
388
389 nlh = nlmsg_put(inst->skb, 0, 0,
390 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
391 sizeof(struct nfgenmsg), 0);
392 if (!nlh)
393 return -1;
394 nfmsg = nlmsg_data(nlh);
395 nfmsg->nfgen_family = pf;
396 nfmsg->version = NFNETLINK_V0;
397 nfmsg->res_id = htons(inst->group_num);
398
399 pmsg.hw_protocol = skb->protocol;
400 pmsg.hook = hooknum;
401
402 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
403 goto nla_put_failure;
404
405 if (prefix &&
406 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
407 goto nla_put_failure;
408
409 if (indev) {
410 #ifndef CONFIG_BRIDGE_NETFILTER
411 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
412 htonl(indev->ifindex)))
413 goto nla_put_failure;
414 #else
415 if (pf == PF_BRIDGE) {
416 /* Case 1: outdev is physical input device, we need to
417 * look for bridge group (when called from
418 * netfilter_bridge) */
419 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
420 htonl(indev->ifindex)) ||
421 /* this is the bridge group "brX" */
422 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
423 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
424 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
425 goto nla_put_failure;
426 } else {
427 /* Case 2: indev is bridge group, we need to look for
428 * physical device (when called from ipv4) */
429 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
430 htonl(indev->ifindex)))
431 goto nla_put_failure;
432 if (skb->nf_bridge && skb->nf_bridge->physindev &&
433 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
434 htonl(skb->nf_bridge->physindev->ifindex)))
435 goto nla_put_failure;
436 }
437 #endif
438 }
439
440 if (outdev) {
441 #ifndef CONFIG_BRIDGE_NETFILTER
442 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
443 htonl(outdev->ifindex)))
444 goto nla_put_failure;
445 #else
446 if (pf == PF_BRIDGE) {
447 /* Case 1: outdev is physical output device, we need to
448 * look for bridge group (when called from
449 * netfilter_bridge) */
450 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
451 htonl(outdev->ifindex)) ||
452 /* this is the bridge group "brX" */
453 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
454 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
455 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
456 goto nla_put_failure;
457 } else {
458 /* Case 2: indev is a bridge group, we need to look
459 * for physical device (when called from ipv4) */
460 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
461 htonl(outdev->ifindex)))
462 goto nla_put_failure;
463 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
464 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
465 htonl(skb->nf_bridge->physoutdev->ifindex)))
466 goto nla_put_failure;
467 }
468 #endif
469 }
470
471 if (skb->mark &&
472 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
473 goto nla_put_failure;
474
475 if (indev && skb->dev &&
476 skb->mac_header != skb->network_header) {
477 struct nfulnl_msg_packet_hw phw;
478 int len = dev_parse_header(skb, phw.hw_addr);
479 if (len > 0) {
480 phw.hw_addrlen = htons(len);
481 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
482 goto nla_put_failure;
483 }
484 }
485
486 if (indev && skb_mac_header_was_set(skb)) {
487 if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
488 nla_put_be16(inst->skb, NFULA_HWLEN,
489 htons(skb->dev->hard_header_len)))
490 goto nla_put_failure;
491
492 hwhdrp = skb_mac_header(skb);
493
494 if (skb->dev->type == ARPHRD_SIT)
495 hwhdrp -= ETH_HLEN;
496
497 if (hwhdrp >= skb->head &&
498 nla_put(inst->skb, NFULA_HWHEADER,
499 skb->dev->hard_header_len, hwhdrp))
500 goto nla_put_failure;
501 }
502
503 if (skb->tstamp.tv64) {
504 struct nfulnl_msg_packet_timestamp ts;
505 struct timeval tv = ktime_to_timeval(skb->tstamp);
506 ts.sec = cpu_to_be64(tv.tv_sec);
507 ts.usec = cpu_to_be64(tv.tv_usec);
508
509 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
510 goto nla_put_failure;
511 }
512
513 /* UID */
514 sk = skb->sk;
515 if (sk && sk->sk_state != TCP_TIME_WAIT) {
516 read_lock_bh(&sk->sk_callback_lock);
517 if (sk->sk_socket && sk->sk_socket->file) {
518 struct file *file = sk->sk_socket->file;
519 const struct cred *cred = file->f_cred;
520 struct user_namespace *user_ns = inst->peer_user_ns;
521 __be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
522 __be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
523 read_unlock_bh(&sk->sk_callback_lock);
524 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
525 nla_put_be32(inst->skb, NFULA_GID, gid))
526 goto nla_put_failure;
527 } else
528 read_unlock_bh(&sk->sk_callback_lock);
529 }
530
531 /* local sequence number */
532 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
533 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
534 goto nla_put_failure;
535
536 /* global sequence number */
537 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
538 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
539 htonl(atomic_inc_return(&global_seq))))
540 goto nla_put_failure;
541
542 if (data_len) {
543 struct nlattr *nla;
544 int size = nla_attr_size(data_len);
545
546 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
547 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
548 return -1;
549 }
550
551 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
552 nla->nla_type = NFULA_PAYLOAD;
553 nla->nla_len = size;
554
555 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
556 BUG();
557 }
558
559 nlh->nlmsg_len = inst->skb->tail - old_tail;
560 return 0;
561
562 nla_put_failure:
563 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
564 return -1;
565 }
566
567 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
568
569 static struct nf_loginfo default_loginfo = {
570 .type = NF_LOG_TYPE_ULOG,
571 .u = {
572 .ulog = {
573 .copy_len = 0xffff,
574 .group = 0,
575 .qthreshold = 1,
576 },
577 },
578 };
579
580 /* log handler for internal netfilter logging api */
581 void
582 nfulnl_log_packet(u_int8_t pf,
583 unsigned int hooknum,
584 const struct sk_buff *skb,
585 const struct net_device *in,
586 const struct net_device *out,
587 const struct nf_loginfo *li_user,
588 const char *prefix)
589 {
590 unsigned int size, data_len;
591 struct nfulnl_instance *inst;
592 const struct nf_loginfo *li;
593 unsigned int qthreshold;
594 unsigned int plen;
595
596 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
597 li = li_user;
598 else
599 li = &default_loginfo;
600
601 inst = instance_lookup_get(li->u.ulog.group);
602 if (!inst)
603 return;
604
605 plen = 0;
606 if (prefix)
607 plen = strlen(prefix) + 1;
608
609 /* FIXME: do we want to make the size calculation conditional based on
610 * what is actually present? way more branches and checks, but more
611 * memory efficient... */
612 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
613 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
614 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
615 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
616 #ifdef CONFIG_BRIDGE_NETFILTER
617 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
618 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
619 #endif
620 + nla_total_size(sizeof(u_int32_t)) /* mark */
621 + nla_total_size(sizeof(u_int32_t)) /* uid */
622 + nla_total_size(sizeof(u_int32_t)) /* gid */
623 + nla_total_size(plen) /* prefix */
624 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
625 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
626
627 if (in && skb_mac_header_was_set(skb)) {
628 size += nla_total_size(skb->dev->hard_header_len)
629 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
630 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
631 }
632
633 spin_lock_bh(&inst->lock);
634
635 if (inst->flags & NFULNL_CFG_F_SEQ)
636 size += nla_total_size(sizeof(u_int32_t));
637 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
638 size += nla_total_size(sizeof(u_int32_t));
639
640 qthreshold = inst->qthreshold;
641 /* per-rule qthreshold overrides per-instance */
642 if (li->u.ulog.qthreshold)
643 if (qthreshold > li->u.ulog.qthreshold)
644 qthreshold = li->u.ulog.qthreshold;
645
646
647 switch (inst->copy_mode) {
648 case NFULNL_COPY_META:
649 case NFULNL_COPY_NONE:
650 data_len = 0;
651 break;
652
653 case NFULNL_COPY_PACKET:
654 if (inst->copy_range == 0
655 || inst->copy_range > skb->len)
656 data_len = skb->len;
657 else
658 data_len = inst->copy_range;
659
660 size += nla_total_size(data_len);
661 break;
662
663 case NFULNL_COPY_DISABLED:
664 default:
665 goto unlock_and_release;
666 }
667
668 if (inst->skb &&
669 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
670 /* either the queue len is too high or we don't have
671 * enough room in the skb left. flush to userspace. */
672 __nfulnl_flush(inst);
673 }
674
675 if (!inst->skb) {
676 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
677 if (!inst->skb)
678 goto alloc_failure;
679 }
680
681 inst->qlen++;
682
683 __build_packet_message(inst, skb, data_len, pf,
684 hooknum, in, out, prefix, plen);
685
686 if (inst->qlen >= qthreshold)
687 __nfulnl_flush(inst);
688 /* timer_pending always called within inst->lock, so there
689 * is no chance of a race here */
690 else if (!timer_pending(&inst->timer)) {
691 instance_get(inst);
692 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
693 add_timer(&inst->timer);
694 }
695
696 unlock_and_release:
697 spin_unlock_bh(&inst->lock);
698 instance_put(inst);
699 return;
700
701 alloc_failure:
702 /* FIXME: statistics */
703 goto unlock_and_release;
704 }
705 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
706
707 static int
708 nfulnl_rcv_nl_event(struct notifier_block *this,
709 unsigned long event, void *ptr)
710 {
711 struct netlink_notify *n = ptr;
712
713 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
714 int i;
715
716 /* destroy all instances for this portid */
717 spin_lock_bh(&instances_lock);
718 for (i = 0; i < INSTANCE_BUCKETS; i++) {
719 struct hlist_node *t2;
720 struct nfulnl_instance *inst;
721 struct hlist_head *head = &instance_table[i];
722
723 hlist_for_each_entry_safe(inst, t2, head, hlist) {
724 if ((net_eq(n->net, &init_net)) &&
725 (n->portid == inst->peer_portid))
726 __instance_destroy(inst);
727 }
728 }
729 spin_unlock_bh(&instances_lock);
730 }
731 return NOTIFY_DONE;
732 }
733
734 static struct notifier_block nfulnl_rtnl_notifier = {
735 .notifier_call = nfulnl_rcv_nl_event,
736 };
737
738 static int
739 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
740 const struct nlmsghdr *nlh,
741 const struct nlattr * const nfqa[])
742 {
743 return -ENOTSUPP;
744 }
745
746 static struct nf_logger nfulnl_logger __read_mostly = {
747 .name = "nfnetlink_log",
748 .logfn = &nfulnl_log_packet,
749 .me = THIS_MODULE,
750 };
751
752 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
753 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
754 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
755 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
756 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
757 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
758 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
759 };
760
761 static int
762 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
763 const struct nlmsghdr *nlh,
764 const struct nlattr * const nfula[])
765 {
766 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
767 u_int16_t group_num = ntohs(nfmsg->res_id);
768 struct nfulnl_instance *inst;
769 struct nfulnl_msg_config_cmd *cmd = NULL;
770 int ret = 0;
771
772 if (nfula[NFULA_CFG_CMD]) {
773 u_int8_t pf = nfmsg->nfgen_family;
774 cmd = nla_data(nfula[NFULA_CFG_CMD]);
775
776 /* Commands without queue context */
777 switch (cmd->command) {
778 case NFULNL_CFG_CMD_PF_BIND:
779 return nf_log_bind_pf(pf, &nfulnl_logger);
780 case NFULNL_CFG_CMD_PF_UNBIND:
781 nf_log_unbind_pf(pf);
782 return 0;
783 }
784 }
785
786 inst = instance_lookup_get(group_num);
787 if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
788 ret = -EPERM;
789 goto out_put;
790 }
791
792 if (cmd != NULL) {
793 switch (cmd->command) {
794 case NFULNL_CFG_CMD_BIND:
795 if (inst) {
796 ret = -EBUSY;
797 goto out_put;
798 }
799
800 inst = instance_create(group_num,
801 NETLINK_CB(skb).portid,
802 sk_user_ns(NETLINK_CB(skb).ssk));
803 if (IS_ERR(inst)) {
804 ret = PTR_ERR(inst);
805 goto out;
806 }
807 break;
808 case NFULNL_CFG_CMD_UNBIND:
809 if (!inst) {
810 ret = -ENODEV;
811 goto out;
812 }
813
814 instance_destroy(inst);
815 goto out_put;
816 default:
817 ret = -ENOTSUPP;
818 break;
819 }
820 }
821
822 if (nfula[NFULA_CFG_MODE]) {
823 struct nfulnl_msg_config_mode *params;
824 params = nla_data(nfula[NFULA_CFG_MODE]);
825
826 if (!inst) {
827 ret = -ENODEV;
828 goto out;
829 }
830 nfulnl_set_mode(inst, params->copy_mode,
831 ntohl(params->copy_range));
832 }
833
834 if (nfula[NFULA_CFG_TIMEOUT]) {
835 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
836
837 if (!inst) {
838 ret = -ENODEV;
839 goto out;
840 }
841 nfulnl_set_timeout(inst, ntohl(timeout));
842 }
843
844 if (nfula[NFULA_CFG_NLBUFSIZ]) {
845 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
846
847 if (!inst) {
848 ret = -ENODEV;
849 goto out;
850 }
851 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
852 }
853
854 if (nfula[NFULA_CFG_QTHRESH]) {
855 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
856
857 if (!inst) {
858 ret = -ENODEV;
859 goto out;
860 }
861 nfulnl_set_qthresh(inst, ntohl(qthresh));
862 }
863
864 if (nfula[NFULA_CFG_FLAGS]) {
865 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
866
867 if (!inst) {
868 ret = -ENODEV;
869 goto out;
870 }
871 nfulnl_set_flags(inst, ntohs(flags));
872 }
873
874 out_put:
875 instance_put(inst);
876 out:
877 return ret;
878 }
879
880 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
881 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
882 .attr_count = NFULA_MAX, },
883 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
884 .attr_count = NFULA_CFG_MAX,
885 .policy = nfula_cfg_policy },
886 };
887
888 static const struct nfnetlink_subsystem nfulnl_subsys = {
889 .name = "log",
890 .subsys_id = NFNL_SUBSYS_ULOG,
891 .cb_count = NFULNL_MSG_MAX,
892 .cb = nfulnl_cb,
893 };
894
895 #ifdef CONFIG_PROC_FS
896 struct iter_state {
897 unsigned int bucket;
898 };
899
900 static struct hlist_node *get_first(struct iter_state *st)
901 {
902 if (!st)
903 return NULL;
904
905 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
906 if (!hlist_empty(&instance_table[st->bucket]))
907 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
908 }
909 return NULL;
910 }
911
912 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
913 {
914 h = rcu_dereference_bh(hlist_next_rcu(h));
915 while (!h) {
916 if (++st->bucket >= INSTANCE_BUCKETS)
917 return NULL;
918
919 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
920 }
921 return h;
922 }
923
924 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
925 {
926 struct hlist_node *head;
927 head = get_first(st);
928
929 if (head)
930 while (pos && (head = get_next(st, head)))
931 pos--;
932 return pos ? NULL : head;
933 }
934
935 static void *seq_start(struct seq_file *seq, loff_t *pos)
936 __acquires(rcu_bh)
937 {
938 rcu_read_lock_bh();
939 return get_idx(seq->private, *pos);
940 }
941
942 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
943 {
944 (*pos)++;
945 return get_next(s->private, v);
946 }
947
948 static void seq_stop(struct seq_file *s, void *v)
949 __releases(rcu_bh)
950 {
951 rcu_read_unlock_bh();
952 }
953
954 static int seq_show(struct seq_file *s, void *v)
955 {
956 const struct nfulnl_instance *inst = v;
957
958 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
959 inst->group_num,
960 inst->peer_portid, inst->qlen,
961 inst->copy_mode, inst->copy_range,
962 inst->flushtimeout, atomic_read(&inst->use));
963 }
964
965 static const struct seq_operations nful_seq_ops = {
966 .start = seq_start,
967 .next = seq_next,
968 .stop = seq_stop,
969 .show = seq_show,
970 };
971
972 static int nful_open(struct inode *inode, struct file *file)
973 {
974 return seq_open_private(file, &nful_seq_ops,
975 sizeof(struct iter_state));
976 }
977
978 static const struct file_operations nful_file_ops = {
979 .owner = THIS_MODULE,
980 .open = nful_open,
981 .read = seq_read,
982 .llseek = seq_lseek,
983 .release = seq_release_private,
984 };
985
986 #endif /* PROC_FS */
987
988 static int __init nfnetlink_log_init(void)
989 {
990 int i, status = -ENOMEM;
991
992 for (i = 0; i < INSTANCE_BUCKETS; i++)
993 INIT_HLIST_HEAD(&instance_table[i]);
994
995 /* it's not really all that important to have a random value, so
996 * we can do this from the init function, even if there hasn't
997 * been that much entropy yet */
998 get_random_bytes(&hash_init, sizeof(hash_init));
999
1000 netlink_register_notifier(&nfulnl_rtnl_notifier);
1001 status = nfnetlink_subsys_register(&nfulnl_subsys);
1002 if (status < 0) {
1003 printk(KERN_ERR "log: failed to create netlink socket\n");
1004 goto cleanup_netlink_notifier;
1005 }
1006
1007 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
1008 if (status < 0) {
1009 printk(KERN_ERR "log: failed to register logger\n");
1010 goto cleanup_subsys;
1011 }
1012
1013 #ifdef CONFIG_PROC_FS
1014 if (!proc_create("nfnetlink_log", 0440,
1015 proc_net_netfilter, &nful_file_ops)) {
1016 status = -ENOMEM;
1017 goto cleanup_logger;
1018 }
1019 #endif
1020 return status;
1021
1022 #ifdef CONFIG_PROC_FS
1023 cleanup_logger:
1024 nf_log_unregister(&nfulnl_logger);
1025 #endif
1026 cleanup_subsys:
1027 nfnetlink_subsys_unregister(&nfulnl_subsys);
1028 cleanup_netlink_notifier:
1029 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1030 return status;
1031 }
1032
1033 static void __exit nfnetlink_log_fini(void)
1034 {
1035 nf_log_unregister(&nfulnl_logger);
1036 #ifdef CONFIG_PROC_FS
1037 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1038 #endif
1039 nfnetlink_subsys_unregister(&nfulnl_subsys);
1040 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1041 }
1042
1043 MODULE_DESCRIPTION("netfilter userspace logging");
1044 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1045 MODULE_LICENSE("GPL");
1046 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1047
1048 module_init(nfnetlink_log_init);
1049 module_exit(nfnetlink_log_fini);
CJK support for tty framebuffer vt