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Merge commit 'c039c332f23e794deb6d6f37b9f07ff3b27fb2cf' into md
[GitHub/mt8127/android_kernel_alcatel_ttab.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 *
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/init.h>
17 #include <linux/ip.h>
18 #include <linux/ipv6.h>
19 #include <linux/netdevice.h>
20 #include <linux/netfilter.h>
21 #include <linux/netlink.h>
22 #include <linux/netfilter/nfnetlink.h>
23 #include <linux/netfilter/nfnetlink_log.h>
24 #include <linux/spinlock.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/list.h>
29 #include <linux/jhash.h>
30 #include <linux/random.h>
31 #include <linux/slab.h>
32 #include <net/sock.h>
33 #include <net/netfilter/nf_log.h>
34 #include <net/netfilter/nfnetlink_log.h>
35
36 #include <linux/atomic.h>
37
38 #ifdef CONFIG_BRIDGE_NETFILTER
39 #include "../bridge/br_private.h"
40 #endif
41
42 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
43 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
44 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
45 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
46
47 #define PRINTR(x, args...) do { if (net_ratelimit()) \
48 printk(x, ## args); } while (0);
49
50 struct nfulnl_instance {
51 struct hlist_node hlist; /* global list of instances */
52 spinlock_t lock;
53 atomic_t use; /* use count */
54
55 unsigned int qlen; /* number of nlmsgs in skb */
56 struct sk_buff *skb; /* pre-allocatd skb */
57 struct timer_list timer;
58 int peer_pid; /* PID of the peer process */
59
60 /* configurable parameters */
61 unsigned int flushtimeout; /* timeout until queue flush */
62 unsigned int nlbufsiz; /* netlink buffer allocation size */
63 unsigned int qthreshold; /* threshold of the queue */
64 u_int32_t copy_range;
65 u_int32_t seq; /* instance-local sequential counter */
66 u_int16_t group_num; /* number of this queue */
67 u_int16_t flags;
68 u_int8_t copy_mode;
69 struct rcu_head rcu;
70 };
71
72 static DEFINE_SPINLOCK(instances_lock);
73 static atomic_t global_seq;
74
75 #define INSTANCE_BUCKETS 16
76 static struct hlist_head instance_table[INSTANCE_BUCKETS];
77 static unsigned int hash_init;
78
79 static inline u_int8_t instance_hashfn(u_int16_t group_num)
80 {
81 return ((group_num & 0xff) % INSTANCE_BUCKETS);
82 }
83
84 static struct nfulnl_instance *
85 __instance_lookup(u_int16_t group_num)
86 {
87 struct hlist_head *head;
88 struct hlist_node *pos;
89 struct nfulnl_instance *inst;
90
91 head = &instance_table[instance_hashfn(group_num)];
92 hlist_for_each_entry_rcu(inst, pos, head, hlist) {
93 if (inst->group_num == group_num)
94 return inst;
95 }
96 return NULL;
97 }
98
99 static inline void
100 instance_get(struct nfulnl_instance *inst)
101 {
102 atomic_inc(&inst->use);
103 }
104
105 static struct nfulnl_instance *
106 instance_lookup_get(u_int16_t group_num)
107 {
108 struct nfulnl_instance *inst;
109
110 rcu_read_lock_bh();
111 inst = __instance_lookup(group_num);
112 if (inst && !atomic_inc_not_zero(&inst->use))
113 inst = NULL;
114 rcu_read_unlock_bh();
115
116 return inst;
117 }
118
119 static void nfulnl_instance_free_rcu(struct rcu_head *head)
120 {
121 kfree(container_of(head, struct nfulnl_instance, rcu));
122 module_put(THIS_MODULE);
123 }
124
125 static void
126 instance_put(struct nfulnl_instance *inst)
127 {
128 if (inst && atomic_dec_and_test(&inst->use))
129 call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
130 }
131
132 static void nfulnl_timer(unsigned long data);
133
134 static struct nfulnl_instance *
135 instance_create(u_int16_t group_num, int pid)
136 {
137 struct nfulnl_instance *inst;
138 int err;
139
140 spin_lock_bh(&instances_lock);
141 if (__instance_lookup(group_num)) {
142 err = -EEXIST;
143 goto out_unlock;
144 }
145
146 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
147 if (!inst) {
148 err = -ENOMEM;
149 goto out_unlock;
150 }
151
152 if (!try_module_get(THIS_MODULE)) {
153 kfree(inst);
154 err = -EAGAIN;
155 goto out_unlock;
156 }
157
158 INIT_HLIST_NODE(&inst->hlist);
159 spin_lock_init(&inst->lock);
160 /* needs to be two, since we _put() after creation */
161 atomic_set(&inst->use, 2);
162
163 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
164
165 inst->peer_pid = pid;
166 inst->group_num = group_num;
167
168 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
169 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
170 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
171 inst->copy_mode = NFULNL_COPY_PACKET;
172 inst->copy_range = NFULNL_COPY_RANGE_MAX;
173
174 hlist_add_head_rcu(&inst->hlist,
175 &instance_table[instance_hashfn(group_num)]);
176
177 spin_unlock_bh(&instances_lock);
178
179 return inst;
180
181 out_unlock:
182 spin_unlock_bh(&instances_lock);
183 return ERR_PTR(err);
184 }
185
186 static void __nfulnl_flush(struct nfulnl_instance *inst);
187
188 /* called with BH disabled */
189 static void
190 __instance_destroy(struct nfulnl_instance *inst)
191 {
192 /* first pull it out of the global list */
193 hlist_del_rcu(&inst->hlist);
194
195 /* then flush all pending packets from skb */
196
197 spin_lock(&inst->lock);
198
199 /* lockless readers wont be able to use us */
200 inst->copy_mode = NFULNL_COPY_DISABLED;
201
202 if (inst->skb)
203 __nfulnl_flush(inst);
204 spin_unlock(&inst->lock);
205
206 /* and finally put the refcount */
207 instance_put(inst);
208 }
209
210 static inline void
211 instance_destroy(struct nfulnl_instance *inst)
212 {
213 spin_lock_bh(&instances_lock);
214 __instance_destroy(inst);
215 spin_unlock_bh(&instances_lock);
216 }
217
218 static int
219 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
220 unsigned int range)
221 {
222 int status = 0;
223
224 spin_lock_bh(&inst->lock);
225
226 switch (mode) {
227 case NFULNL_COPY_NONE:
228 case NFULNL_COPY_META:
229 inst->copy_mode = mode;
230 inst->copy_range = 0;
231 break;
232
233 case NFULNL_COPY_PACKET:
234 inst->copy_mode = mode;
235 inst->copy_range = min_t(unsigned int,
236 range, NFULNL_COPY_RANGE_MAX);
237 break;
238
239 default:
240 status = -EINVAL;
241 break;
242 }
243
244 spin_unlock_bh(&inst->lock);
245
246 return status;
247 }
248
249 static int
250 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
251 {
252 int status;
253
254 spin_lock_bh(&inst->lock);
255 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
256 status = -ERANGE;
257 else if (nlbufsiz > 131072)
258 status = -ERANGE;
259 else {
260 inst->nlbufsiz = nlbufsiz;
261 status = 0;
262 }
263 spin_unlock_bh(&inst->lock);
264
265 return status;
266 }
267
268 static int
269 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
270 {
271 spin_lock_bh(&inst->lock);
272 inst->flushtimeout = timeout;
273 spin_unlock_bh(&inst->lock);
274
275 return 0;
276 }
277
278 static int
279 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
280 {
281 spin_lock_bh(&inst->lock);
282 inst->qthreshold = qthresh;
283 spin_unlock_bh(&inst->lock);
284
285 return 0;
286 }
287
288 static int
289 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
290 {
291 spin_lock_bh(&inst->lock);
292 inst->flags = flags;
293 spin_unlock_bh(&inst->lock);
294
295 return 0;
296 }
297
298 static struct sk_buff *
299 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
300 {
301 struct sk_buff *skb;
302 unsigned int n;
303
304 /* alloc skb which should be big enough for a whole multipart
305 * message. WARNING: has to be <= 128k due to slab restrictions */
306
307 n = max(inst_size, pkt_size);
308 skb = alloc_skb(n, GFP_ATOMIC);
309 if (!skb) {
310 if (n > pkt_size) {
311 /* try to allocate only as much as we need for current
312 * packet */
313
314 skb = alloc_skb(pkt_size, GFP_ATOMIC);
315 if (!skb)
316 pr_err("nfnetlink_log: can't even alloc %u bytes\n",
317 pkt_size);
318 }
319 }
320
321 return skb;
322 }
323
324 static int
325 __nfulnl_send(struct nfulnl_instance *inst)
326 {
327 int status = -1;
328
329 if (inst->qlen > 1) {
330 struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
331 NLMSG_DONE,
332 sizeof(struct nfgenmsg),
333 0);
334 if (!nlh)
335 goto out;
336 }
337 status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid,
338 MSG_DONTWAIT);
339
340 inst->qlen = 0;
341 inst->skb = NULL;
342 out:
343 return status;
344 }
345
346 static void
347 __nfulnl_flush(struct nfulnl_instance *inst)
348 {
349 /* timer holds a reference */
350 if (del_timer(&inst->timer))
351 instance_put(inst);
352 if (inst->skb)
353 __nfulnl_send(inst);
354 }
355
356 static void
357 nfulnl_timer(unsigned long data)
358 {
359 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
360
361 spin_lock_bh(&inst->lock);
362 if (inst->skb)
363 __nfulnl_send(inst);
364 spin_unlock_bh(&inst->lock);
365 instance_put(inst);
366 }
367
368 /* This is an inline function, we don't really care about a long
369 * list of arguments */
370 static inline int
371 __build_packet_message(struct nfulnl_instance *inst,
372 const struct sk_buff *skb,
373 unsigned int data_len,
374 u_int8_t pf,
375 unsigned int hooknum,
376 const struct net_device *indev,
377 const struct net_device *outdev,
378 const char *prefix, unsigned int plen)
379 {
380 struct nfulnl_msg_packet_hdr pmsg;
381 struct nlmsghdr *nlh;
382 struct nfgenmsg *nfmsg;
383 sk_buff_data_t old_tail = inst->skb->tail;
384
385 nlh = nlmsg_put(inst->skb, 0, 0,
386 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
387 sizeof(struct nfgenmsg), 0);
388 if (!nlh)
389 return -1;
390 nfmsg = nlmsg_data(nlh);
391 nfmsg->nfgen_family = pf;
392 nfmsg->version = NFNETLINK_V0;
393 nfmsg->res_id = htons(inst->group_num);
394
395 pmsg.hw_protocol = skb->protocol;
396 pmsg.hook = hooknum;
397
398 if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
399 goto nla_put_failure;
400
401 if (prefix &&
402 nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
403 goto nla_put_failure;
404
405 if (indev) {
406 #ifndef CONFIG_BRIDGE_NETFILTER
407 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
408 htonl(indev->ifindex)))
409 goto nla_put_failure;
410 #else
411 if (pf == PF_BRIDGE) {
412 /* Case 1: outdev is physical input device, we need to
413 * look for bridge group (when called from
414 * netfilter_bridge) */
415 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
416 htonl(indev->ifindex)) ||
417 /* this is the bridge group "brX" */
418 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
419 nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
420 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
421 goto nla_put_failure;
422 } else {
423 /* Case 2: indev is bridge group, we need to look for
424 * physical device (when called from ipv4) */
425 if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
426 htonl(indev->ifindex)))
427 goto nla_put_failure;
428 if (skb->nf_bridge && skb->nf_bridge->physindev &&
429 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
430 htonl(skb->nf_bridge->physindev->ifindex)))
431 goto nla_put_failure;
432 }
433 #endif
434 }
435
436 if (outdev) {
437 #ifndef CONFIG_BRIDGE_NETFILTER
438 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
439 htonl(outdev->ifindex)))
440 goto nla_put_failure;
441 #else
442 if (pf == PF_BRIDGE) {
443 /* Case 1: outdev is physical output device, we need to
444 * look for bridge group (when called from
445 * netfilter_bridge) */
446 if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
447 htonl(outdev->ifindex)) ||
448 /* this is the bridge group "brX" */
449 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
450 nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
451 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
452 goto nla_put_failure;
453 } else {
454 /* Case 2: indev is a bridge group, we need to look
455 * for physical device (when called from ipv4) */
456 if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
457 htonl(outdev->ifindex)))
458 goto nla_put_failure;
459 if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
460 nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
461 htonl(skb->nf_bridge->physoutdev->ifindex)))
462 goto nla_put_failure;
463 }
464 #endif
465 }
466
467 if (skb->mark &&
468 nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
469 goto nla_put_failure;
470
471 if (indev && skb->dev &&
472 skb->mac_header != skb->network_header) {
473 struct nfulnl_msg_packet_hw phw;
474 int len = dev_parse_header(skb, phw.hw_addr);
475 if (len > 0) {
476 phw.hw_addrlen = htons(len);
477 if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
478 goto nla_put_failure;
479 }
480 }
481
482 if (indev && skb_mac_header_was_set(skb)) {
483 if (nla_put_be32(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
484 nla_put_be16(inst->skb, NFULA_HWLEN,
485 htons(skb->dev->hard_header_len)) ||
486 nla_put(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
487 skb_mac_header(skb)))
488 goto nla_put_failure;
489 }
490
491 if (skb->tstamp.tv64) {
492 struct nfulnl_msg_packet_timestamp ts;
493 struct timeval tv = ktime_to_timeval(skb->tstamp);
494 ts.sec = cpu_to_be64(tv.tv_sec);
495 ts.usec = cpu_to_be64(tv.tv_usec);
496
497 if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
498 goto nla_put_failure;
499 }
500
501 /* UID */
502 if (skb->sk) {
503 read_lock_bh(&skb->sk->sk_callback_lock);
504 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
505 struct file *file = skb->sk->sk_socket->file;
506 __be32 uid = htonl(file->f_cred->fsuid);
507 __be32 gid = htonl(file->f_cred->fsgid);
508 read_unlock_bh(&skb->sk->sk_callback_lock);
509 if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
510 nla_put_be32(inst->skb, NFULA_GID, gid))
511 goto nla_put_failure;
512 } else
513 read_unlock_bh(&skb->sk->sk_callback_lock);
514 }
515
516 /* local sequence number */
517 if ((inst->flags & NFULNL_CFG_F_SEQ) &&
518 nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
519 goto nla_put_failure;
520
521 /* global sequence number */
522 if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
523 nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
524 htonl(atomic_inc_return(&global_seq))))
525 goto nla_put_failure;
526
527 if (data_len) {
528 struct nlattr *nla;
529 int size = nla_attr_size(data_len);
530
531 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
532 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
533 return -1;
534 }
535
536 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
537 nla->nla_type = NFULA_PAYLOAD;
538 nla->nla_len = size;
539
540 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
541 BUG();
542 }
543
544 nlh->nlmsg_len = inst->skb->tail - old_tail;
545 return 0;
546
547 nla_put_failure:
548 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
549 return -1;
550 }
551
552 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
553
554 static struct nf_loginfo default_loginfo = {
555 .type = NF_LOG_TYPE_ULOG,
556 .u = {
557 .ulog = {
558 .copy_len = 0xffff,
559 .group = 0,
560 .qthreshold = 1,
561 },
562 },
563 };
564
565 /* log handler for internal netfilter logging api */
566 void
567 nfulnl_log_packet(u_int8_t pf,
568 unsigned int hooknum,
569 const struct sk_buff *skb,
570 const struct net_device *in,
571 const struct net_device *out,
572 const struct nf_loginfo *li_user,
573 const char *prefix)
574 {
575 unsigned int size, data_len;
576 struct nfulnl_instance *inst;
577 const struct nf_loginfo *li;
578 unsigned int qthreshold;
579 unsigned int plen;
580
581 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
582 li = li_user;
583 else
584 li = &default_loginfo;
585
586 inst = instance_lookup_get(li->u.ulog.group);
587 if (!inst)
588 return;
589
590 plen = 0;
591 if (prefix)
592 plen = strlen(prefix) + 1;
593
594 /* FIXME: do we want to make the size calculation conditional based on
595 * what is actually present? way more branches and checks, but more
596 * memory efficient... */
597 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
598 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
599 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
600 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
601 #ifdef CONFIG_BRIDGE_NETFILTER
602 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
603 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
604 #endif
605 + nla_total_size(sizeof(u_int32_t)) /* mark */
606 + nla_total_size(sizeof(u_int32_t)) /* uid */
607 + nla_total_size(sizeof(u_int32_t)) /* gid */
608 + nla_total_size(plen) /* prefix */
609 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
610 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
611
612 if (in && skb_mac_header_was_set(skb)) {
613 size += nla_total_size(skb->dev->hard_header_len)
614 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
615 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
616 }
617
618 spin_lock_bh(&inst->lock);
619
620 if (inst->flags & NFULNL_CFG_F_SEQ)
621 size += nla_total_size(sizeof(u_int32_t));
622 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
623 size += nla_total_size(sizeof(u_int32_t));
624
625 qthreshold = inst->qthreshold;
626 /* per-rule qthreshold overrides per-instance */
627 if (li->u.ulog.qthreshold)
628 if (qthreshold > li->u.ulog.qthreshold)
629 qthreshold = li->u.ulog.qthreshold;
630
631
632 switch (inst->copy_mode) {
633 case NFULNL_COPY_META:
634 case NFULNL_COPY_NONE:
635 data_len = 0;
636 break;
637
638 case NFULNL_COPY_PACKET:
639 if (inst->copy_range == 0
640 || inst->copy_range > skb->len)
641 data_len = skb->len;
642 else
643 data_len = inst->copy_range;
644
645 size += nla_total_size(data_len);
646 break;
647
648 case NFULNL_COPY_DISABLED:
649 default:
650 goto unlock_and_release;
651 }
652
653 if (inst->skb &&
654 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
655 /* either the queue len is too high or we don't have
656 * enough room in the skb left. flush to userspace. */
657 __nfulnl_flush(inst);
658 }
659
660 if (!inst->skb) {
661 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
662 if (!inst->skb)
663 goto alloc_failure;
664 }
665
666 inst->qlen++;
667
668 __build_packet_message(inst, skb, data_len, pf,
669 hooknum, in, out, prefix, plen);
670
671 if (inst->qlen >= qthreshold)
672 __nfulnl_flush(inst);
673 /* timer_pending always called within inst->lock, so there
674 * is no chance of a race here */
675 else if (!timer_pending(&inst->timer)) {
676 instance_get(inst);
677 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
678 add_timer(&inst->timer);
679 }
680
681 unlock_and_release:
682 spin_unlock_bh(&inst->lock);
683 instance_put(inst);
684 return;
685
686 alloc_failure:
687 /* FIXME: statistics */
688 goto unlock_and_release;
689 }
690 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
691
692 static int
693 nfulnl_rcv_nl_event(struct notifier_block *this,
694 unsigned long event, void *ptr)
695 {
696 struct netlink_notify *n = ptr;
697
698 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
699 int i;
700
701 /* destroy all instances for this pid */
702 spin_lock_bh(&instances_lock);
703 for (i = 0; i < INSTANCE_BUCKETS; i++) {
704 struct hlist_node *tmp, *t2;
705 struct nfulnl_instance *inst;
706 struct hlist_head *head = &instance_table[i];
707
708 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
709 if ((net_eq(n->net, &init_net)) &&
710 (n->pid == inst->peer_pid))
711 __instance_destroy(inst);
712 }
713 }
714 spin_unlock_bh(&instances_lock);
715 }
716 return NOTIFY_DONE;
717 }
718
719 static struct notifier_block nfulnl_rtnl_notifier = {
720 .notifier_call = nfulnl_rcv_nl_event,
721 };
722
723 static int
724 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
725 const struct nlmsghdr *nlh,
726 const struct nlattr * const nfqa[])
727 {
728 return -ENOTSUPP;
729 }
730
731 static struct nf_logger nfulnl_logger __read_mostly = {
732 .name = "nfnetlink_log",
733 .logfn = &nfulnl_log_packet,
734 .me = THIS_MODULE,
735 };
736
737 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
738 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
739 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
740 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
741 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
742 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
743 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
744 };
745
746 static int
747 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
748 const struct nlmsghdr *nlh,
749 const struct nlattr * const nfula[])
750 {
751 struct nfgenmsg *nfmsg = nlmsg_data(nlh);
752 u_int16_t group_num = ntohs(nfmsg->res_id);
753 struct nfulnl_instance *inst;
754 struct nfulnl_msg_config_cmd *cmd = NULL;
755 int ret = 0;
756
757 if (nfula[NFULA_CFG_CMD]) {
758 u_int8_t pf = nfmsg->nfgen_family;
759 cmd = nla_data(nfula[NFULA_CFG_CMD]);
760
761 /* Commands without queue context */
762 switch (cmd->command) {
763 case NFULNL_CFG_CMD_PF_BIND:
764 return nf_log_bind_pf(pf, &nfulnl_logger);
765 case NFULNL_CFG_CMD_PF_UNBIND:
766 nf_log_unbind_pf(pf);
767 return 0;
768 }
769 }
770
771 inst = instance_lookup_get(group_num);
772 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
773 ret = -EPERM;
774 goto out_put;
775 }
776
777 if (cmd != NULL) {
778 switch (cmd->command) {
779 case NFULNL_CFG_CMD_BIND:
780 if (inst) {
781 ret = -EBUSY;
782 goto out_put;
783 }
784
785 inst = instance_create(group_num,
786 NETLINK_CB(skb).pid);
787 if (IS_ERR(inst)) {
788 ret = PTR_ERR(inst);
789 goto out;
790 }
791 break;
792 case NFULNL_CFG_CMD_UNBIND:
793 if (!inst) {
794 ret = -ENODEV;
795 goto out;
796 }
797
798 instance_destroy(inst);
799 goto out_put;
800 default:
801 ret = -ENOTSUPP;
802 break;
803 }
804 }
805
806 if (nfula[NFULA_CFG_MODE]) {
807 struct nfulnl_msg_config_mode *params;
808 params = nla_data(nfula[NFULA_CFG_MODE]);
809
810 if (!inst) {
811 ret = -ENODEV;
812 goto out;
813 }
814 nfulnl_set_mode(inst, params->copy_mode,
815 ntohl(params->copy_range));
816 }
817
818 if (nfula[NFULA_CFG_TIMEOUT]) {
819 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
820
821 if (!inst) {
822 ret = -ENODEV;
823 goto out;
824 }
825 nfulnl_set_timeout(inst, ntohl(timeout));
826 }
827
828 if (nfula[NFULA_CFG_NLBUFSIZ]) {
829 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
830
831 if (!inst) {
832 ret = -ENODEV;
833 goto out;
834 }
835 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
836 }
837
838 if (nfula[NFULA_CFG_QTHRESH]) {
839 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
840
841 if (!inst) {
842 ret = -ENODEV;
843 goto out;
844 }
845 nfulnl_set_qthresh(inst, ntohl(qthresh));
846 }
847
848 if (nfula[NFULA_CFG_FLAGS]) {
849 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
850
851 if (!inst) {
852 ret = -ENODEV;
853 goto out;
854 }
855 nfulnl_set_flags(inst, ntohs(flags));
856 }
857
858 out_put:
859 instance_put(inst);
860 out:
861 return ret;
862 }
863
864 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
865 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
866 .attr_count = NFULA_MAX, },
867 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
868 .attr_count = NFULA_CFG_MAX,
869 .policy = nfula_cfg_policy },
870 };
871
872 static const struct nfnetlink_subsystem nfulnl_subsys = {
873 .name = "log",
874 .subsys_id = NFNL_SUBSYS_ULOG,
875 .cb_count = NFULNL_MSG_MAX,
876 .cb = nfulnl_cb,
877 };
878
879 #ifdef CONFIG_PROC_FS
880 struct iter_state {
881 unsigned int bucket;
882 };
883
884 static struct hlist_node *get_first(struct iter_state *st)
885 {
886 if (!st)
887 return NULL;
888
889 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
890 if (!hlist_empty(&instance_table[st->bucket]))
891 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
892 }
893 return NULL;
894 }
895
896 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
897 {
898 h = rcu_dereference_bh(hlist_next_rcu(h));
899 while (!h) {
900 if (++st->bucket >= INSTANCE_BUCKETS)
901 return NULL;
902
903 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
904 }
905 return h;
906 }
907
908 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
909 {
910 struct hlist_node *head;
911 head = get_first(st);
912
913 if (head)
914 while (pos && (head = get_next(st, head)))
915 pos--;
916 return pos ? NULL : head;
917 }
918
919 static void *seq_start(struct seq_file *seq, loff_t *pos)
920 __acquires(rcu_bh)
921 {
922 rcu_read_lock_bh();
923 return get_idx(seq->private, *pos);
924 }
925
926 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
927 {
928 (*pos)++;
929 return get_next(s->private, v);
930 }
931
932 static void seq_stop(struct seq_file *s, void *v)
933 __releases(rcu_bh)
934 {
935 rcu_read_unlock_bh();
936 }
937
938 static int seq_show(struct seq_file *s, void *v)
939 {
940 const struct nfulnl_instance *inst = v;
941
942 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
943 inst->group_num,
944 inst->peer_pid, inst->qlen,
945 inst->copy_mode, inst->copy_range,
946 inst->flushtimeout, atomic_read(&inst->use));
947 }
948
949 static const struct seq_operations nful_seq_ops = {
950 .start = seq_start,
951 .next = seq_next,
952 .stop = seq_stop,
953 .show = seq_show,
954 };
955
956 static int nful_open(struct inode *inode, struct file *file)
957 {
958 return seq_open_private(file, &nful_seq_ops,
959 sizeof(struct iter_state));
960 }
961
962 static const struct file_operations nful_file_ops = {
963 .owner = THIS_MODULE,
964 .open = nful_open,
965 .read = seq_read,
966 .llseek = seq_lseek,
967 .release = seq_release_private,
968 };
969
970 #endif /* PROC_FS */
971
972 static int __init nfnetlink_log_init(void)
973 {
974 int i, status = -ENOMEM;
975
976 for (i = 0; i < INSTANCE_BUCKETS; i++)
977 INIT_HLIST_HEAD(&instance_table[i]);
978
979 /* it's not really all that important to have a random value, so
980 * we can do this from the init function, even if there hasn't
981 * been that much entropy yet */
982 get_random_bytes(&hash_init, sizeof(hash_init));
983
984 netlink_register_notifier(&nfulnl_rtnl_notifier);
985 status = nfnetlink_subsys_register(&nfulnl_subsys);
986 if (status < 0) {
987 printk(KERN_ERR "log: failed to create netlink socket\n");
988 goto cleanup_netlink_notifier;
989 }
990
991 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
992 if (status < 0) {
993 printk(KERN_ERR "log: failed to register logger\n");
994 goto cleanup_subsys;
995 }
996
997 #ifdef CONFIG_PROC_FS
998 if (!proc_create("nfnetlink_log", 0440,
999 proc_net_netfilter, &nful_file_ops))
1000 goto cleanup_logger;
1001 #endif
1002 return status;
1003
1004 #ifdef CONFIG_PROC_FS
1005 cleanup_logger:
1006 nf_log_unregister(&nfulnl_logger);
1007 #endif
1008 cleanup_subsys:
1009 nfnetlink_subsys_unregister(&nfulnl_subsys);
1010 cleanup_netlink_notifier:
1011 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1012 return status;
1013 }
1014
1015 static void __exit nfnetlink_log_fini(void)
1016 {
1017 nf_log_unregister(&nfulnl_logger);
1018 #ifdef CONFIG_PROC_FS
1019 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1020 #endif
1021 nfnetlink_subsys_unregister(&nfulnl_subsys);
1022 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1023 }
1024
1025 MODULE_DESCRIPTION("netfilter userspace logging");
1026 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1027 MODULE_LICENSE("GPL");
1028 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1029
1030 module_init(nfnetlink_log_init);
1031 module_exit(nfnetlink_log_fini);
kernel source for telekom puls (alcatel/mediatek)