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firewire: prevent userspace from accessing shut down devices
[linux-2.6/mini2440.git] / net / netfilter / nfnetlink_log.c
blobb8173af8c24a7d9d1f296123b52dfc05a0063dc0
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 <net/sock.h>
32 #include <net/netfilter/nf_log.h>
33
34 #include <asm/atomic.h>
35
36 #ifdef CONFIG_BRIDGE_NETFILTER
37 #include "../bridge/br_private.h"
38 #endif
39
40 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
41 #define NFULNL_TIMEOUT_DEFAULT HZ /* every second */
42 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
43 #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */
44
45 #define PRINTR(x, args...) do { if (net_ratelimit()) \
46 printk(x, ## args); } while (0);
47
48 struct nfulnl_instance {
49 struct hlist_node hlist; /* global list of instances */
50 spinlock_t lock;
51 atomic_t use; /* use count */
52
53 unsigned int qlen; /* number of nlmsgs in skb */
54 struct sk_buff *skb; /* pre-allocatd skb */
55 struct timer_list timer;
56 int peer_pid; /* PID of the peer process */
57
58 /* configurable parameters */
59 unsigned int flushtimeout; /* timeout until queue flush */
60 unsigned int nlbufsiz; /* netlink buffer allocation size */
61 unsigned int qthreshold; /* threshold of the queue */
62 u_int32_t copy_range;
63 u_int32_t seq; /* instance-local sequential counter */
64 u_int16_t group_num; /* number of this queue */
65 u_int16_t flags;
66 u_int8_t copy_mode;
67 };
68
69 static DEFINE_RWLOCK(instances_lock);
70 static atomic_t global_seq;
71
72 #define INSTANCE_BUCKETS 16
73 static struct hlist_head instance_table[INSTANCE_BUCKETS];
74 static unsigned int hash_init;
75
76 static inline u_int8_t instance_hashfn(u_int16_t group_num)
77 {
78 return ((group_num & 0xff) % INSTANCE_BUCKETS);
79 }
80
81 static struct nfulnl_instance *
82 __instance_lookup(u_int16_t group_num)
83 {
84 struct hlist_head *head;
85 struct hlist_node *pos;
86 struct nfulnl_instance *inst;
87
88 head = &instance_table[instance_hashfn(group_num)];
89 hlist_for_each_entry(inst, pos, head, hlist) {
90 if (inst->group_num == group_num)
91 return inst;
92 }
93 return NULL;
94 }
95
96 static inline void
97 instance_get(struct nfulnl_instance *inst)
98 {
99 atomic_inc(&inst->use);
100 }
101
102 static struct nfulnl_instance *
103 instance_lookup_get(u_int16_t group_num)
104 {
105 struct nfulnl_instance *inst;
106
107 read_lock_bh(&instances_lock);
108 inst = __instance_lookup(group_num);
109 if (inst)
110 instance_get(inst);
111 read_unlock_bh(&instances_lock);
112
113 return inst;
114 }
115
116 static void
117 instance_put(struct nfulnl_instance *inst)
118 {
119 if (inst && atomic_dec_and_test(&inst->use)) {
120 kfree(inst);
121 module_put(THIS_MODULE);
122 }
123 }
124
125 static void nfulnl_timer(unsigned long data);
126
127 static struct nfulnl_instance *
128 instance_create(u_int16_t group_num, int pid)
129 {
130 struct nfulnl_instance *inst;
131 int err;
132
133 write_lock_bh(&instances_lock);
134 if (__instance_lookup(group_num)) {
135 err = -EEXIST;
136 goto out_unlock;
137 }
138
139 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
140 if (!inst) {
141 err = -ENOMEM;
142 goto out_unlock;
143 }
144
145 if (!try_module_get(THIS_MODULE)) {
146 kfree(inst);
147 err = -EAGAIN;
148 goto out_unlock;
149 }
150
151 INIT_HLIST_NODE(&inst->hlist);
152 spin_lock_init(&inst->lock);
153 /* needs to be two, since we _put() after creation */
154 atomic_set(&inst->use, 2);
155
156 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
157
158 inst->peer_pid = pid;
159 inst->group_num = group_num;
160
161 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
162 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
163 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
164 inst->copy_mode = NFULNL_COPY_PACKET;
165 inst->copy_range = NFULNL_COPY_RANGE_MAX;
166
167 hlist_add_head(&inst->hlist,
168 &instance_table[instance_hashfn(group_num)]);
169
170 write_unlock_bh(&instances_lock);
171
172 return inst;
173
174 out_unlock:
175 write_unlock_bh(&instances_lock);
176 return ERR_PTR(err);
177 }
178
179 static void __nfulnl_flush(struct nfulnl_instance *inst);
180
181 static void
182 __instance_destroy(struct nfulnl_instance *inst)
183 {
184 /* first pull it out of the global list */
185 hlist_del(&inst->hlist);
186
187 /* then flush all pending packets from skb */
188
189 spin_lock_bh(&inst->lock);
190 if (inst->skb)
191 __nfulnl_flush(inst);
192 spin_unlock_bh(&inst->lock);
193
194 /* and finally put the refcount */
195 instance_put(inst);
196 }
197
198 static inline void
199 instance_destroy(struct nfulnl_instance *inst)
200 {
201 write_lock_bh(&instances_lock);
202 __instance_destroy(inst);
203 write_unlock_bh(&instances_lock);
204 }
205
206 static int
207 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
208 unsigned int range)
209 {
210 int status = 0;
211
212 spin_lock_bh(&inst->lock);
213
214 switch (mode) {
215 case NFULNL_COPY_NONE:
216 case NFULNL_COPY_META:
217 inst->copy_mode = mode;
218 inst->copy_range = 0;
219 break;
220
221 case NFULNL_COPY_PACKET:
222 inst->copy_mode = mode;
223 inst->copy_range = min_t(unsigned int,
224 range, NFULNL_COPY_RANGE_MAX);
225 break;
226
227 default:
228 status = -EINVAL;
229 break;
230 }
231
232 spin_unlock_bh(&inst->lock);
233
234 return status;
235 }
236
237 static int
238 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
239 {
240 int status;
241
242 spin_lock_bh(&inst->lock);
243 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
244 status = -ERANGE;
245 else if (nlbufsiz > 131072)
246 status = -ERANGE;
247 else {
248 inst->nlbufsiz = nlbufsiz;
249 status = 0;
250 }
251 spin_unlock_bh(&inst->lock);
252
253 return status;
254 }
255
256 static int
257 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
258 {
259 spin_lock_bh(&inst->lock);
260 inst->flushtimeout = timeout;
261 spin_unlock_bh(&inst->lock);
262
263 return 0;
264 }
265
266 static int
267 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
268 {
269 spin_lock_bh(&inst->lock);
270 inst->qthreshold = qthresh;
271 spin_unlock_bh(&inst->lock);
272
273 return 0;
274 }
275
276 static int
277 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
278 {
279 spin_lock_bh(&inst->lock);
280 inst->flags = flags;
281 spin_unlock_bh(&inst->lock);
282
283 return 0;
284 }
285
286 static struct sk_buff *
287 nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size)
288 {
289 struct sk_buff *skb;
290 unsigned int n;
291
292 /* alloc skb which should be big enough for a whole multipart
293 * message. WARNING: has to be <= 128k due to slab restrictions */
294
295 n = max(inst_size, pkt_size);
296 skb = alloc_skb(n, GFP_ATOMIC);
297 if (!skb) {
298 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
299 inst_size);
300
301 if (n > pkt_size) {
302 /* try to allocate only as much as we need for current
303 * packet */
304
305 skb = alloc_skb(pkt_size, GFP_ATOMIC);
306 if (!skb)
307 PRINTR("nfnetlink_log: can't even alloc %u "
308 "bytes\n", pkt_size);
309 }
310 }
311
312 return skb;
313 }
314
315 static int
316 __nfulnl_send(struct nfulnl_instance *inst)
317 {
318 int status = -1;
319
320 if (inst->qlen > 1)
321 NLMSG_PUT(inst->skb, 0, 0,
322 NLMSG_DONE,
323 sizeof(struct nfgenmsg));
324
325 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
326
327 inst->qlen = 0;
328 inst->skb = NULL;
329
330 nlmsg_failure:
331 return status;
332 }
333
334 static void
335 __nfulnl_flush(struct nfulnl_instance *inst)
336 {
337 /* timer holds a reference */
338 if (del_timer(&inst->timer))
339 instance_put(inst);
340 if (inst->skb)
341 __nfulnl_send(inst);
342 }
343
344 static void
345 nfulnl_timer(unsigned long data)
346 {
347 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
348
349 spin_lock_bh(&inst->lock);
350 if (inst->skb)
351 __nfulnl_send(inst);
352 spin_unlock_bh(&inst->lock);
353 instance_put(inst);
354 }
355
356 /* This is an inline function, we don't really care about a long
357 * list of arguments */
358 static inline int
359 __build_packet_message(struct nfulnl_instance *inst,
360 const struct sk_buff *skb,
361 unsigned int data_len,
362 unsigned int pf,
363 unsigned int hooknum,
364 const struct net_device *indev,
365 const struct net_device *outdev,
366 const struct nf_loginfo *li,
367 const char *prefix, unsigned int plen)
368 {
369 struct nfulnl_msg_packet_hdr pmsg;
370 struct nlmsghdr *nlh;
371 struct nfgenmsg *nfmsg;
372 __be32 tmp_uint;
373 sk_buff_data_t old_tail = inst->skb->tail;
374
375 nlh = NLMSG_PUT(inst->skb, 0, 0,
376 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
377 sizeof(struct nfgenmsg));
378 nfmsg = NLMSG_DATA(nlh);
379 nfmsg->nfgen_family = pf;
380 nfmsg->version = NFNETLINK_V0;
381 nfmsg->res_id = htons(inst->group_num);
382
383 pmsg.hw_protocol = skb->protocol;
384 pmsg.hook = hooknum;
385
386 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
387
388 if (prefix)
389 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
390
391 if (indev) {
392 #ifndef CONFIG_BRIDGE_NETFILTER
393 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
394 htonl(indev->ifindex));
395 #else
396 if (pf == PF_BRIDGE) {
397 /* Case 1: outdev is physical input device, we need to
398 * look for bridge group (when called from
399 * netfilter_bridge) */
400 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
401 htonl(indev->ifindex));
402 /* this is the bridge group "brX" */
403 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
404 htonl(indev->br_port->br->dev->ifindex));
405 } else {
406 /* Case 2: indev is bridge group, we need to look for
407 * physical device (when called from ipv4) */
408 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
409 htonl(indev->ifindex));
410 if (skb->nf_bridge && skb->nf_bridge->physindev)
411 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
412 htonl(skb->nf_bridge->physindev->ifindex));
413 }
414 #endif
415 }
416
417 if (outdev) {
418 tmp_uint = htonl(outdev->ifindex);
419 #ifndef CONFIG_BRIDGE_NETFILTER
420 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
421 htonl(outdev->ifindex));
422 #else
423 if (pf == PF_BRIDGE) {
424 /* Case 1: outdev is physical output device, we need to
425 * look for bridge group (when called from
426 * netfilter_bridge) */
427 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
428 htonl(outdev->ifindex));
429 /* this is the bridge group "brX" */
430 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
431 htonl(outdev->br_port->br->dev->ifindex));
432 } else {
433 /* Case 2: indev is a bridge group, we need to look
434 * for physical device (when called from ipv4) */
435 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
436 htonl(outdev->ifindex));
437 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
438 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
439 htonl(skb->nf_bridge->physoutdev->ifindex));
440 }
441 #endif
442 }
443
444 if (skb->mark)
445 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
446
447 if (indev && skb->dev) {
448 struct nfulnl_msg_packet_hw phw;
449 int len = dev_parse_header(skb, phw.hw_addr);
450 if (len > 0) {
451 phw.hw_addrlen = htons(len);
452 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
453 }
454 }
455
456 if (skb->tstamp.tv64) {
457 struct nfulnl_msg_packet_timestamp ts;
458 struct timeval tv = ktime_to_timeval(skb->tstamp);
459 ts.sec = cpu_to_be64(tv.tv_sec);
460 ts.usec = cpu_to_be64(tv.tv_usec);
461
462 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
463 }
464
465 /* UID */
466 if (skb->sk) {
467 read_lock_bh(&skb->sk->sk_callback_lock);
468 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
469 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
470 __be32 gid = htonl(skb->sk->sk_socket->file->f_gid);
471 /* need to unlock here since NLA_PUT may goto */
472 read_unlock_bh(&skb->sk->sk_callback_lock);
473 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
474 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
475 } else
476 read_unlock_bh(&skb->sk->sk_callback_lock);
477 }
478
479 /* local sequence number */
480 if (inst->flags & NFULNL_CFG_F_SEQ)
481 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
482
483 /* global sequence number */
484 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
485 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
486 htonl(atomic_inc_return(&global_seq)));
487
488 if (data_len) {
489 struct nlattr *nla;
490 int size = nla_attr_size(data_len);
491
492 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
493 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
494 goto nlmsg_failure;
495 }
496
497 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
498 nla->nla_type = NFULA_PAYLOAD;
499 nla->nla_len = size;
500
501 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
502 BUG();
503 }
504
505 nlh->nlmsg_len = inst->skb->tail - old_tail;
506 return 0;
507
508 nlmsg_failure:
509 nla_put_failure:
510 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
511 return -1;
512 }
513
514 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
515
516 static struct nf_loginfo default_loginfo = {
517 .type = NF_LOG_TYPE_ULOG,
518 .u = {
519 .ulog = {
520 .copy_len = 0xffff,
521 .group = 0,
522 .qthreshold = 1,
523 },
524 },
525 };
526
527 /* log handler for internal netfilter logging api */
528 static void
529 nfulnl_log_packet(unsigned int pf,
530 unsigned int hooknum,
531 const struct sk_buff *skb,
532 const struct net_device *in,
533 const struct net_device *out,
534 const struct nf_loginfo *li_user,
535 const char *prefix)
536 {
537 unsigned int size, data_len;
538 struct nfulnl_instance *inst;
539 const struct nf_loginfo *li;
540 unsigned int qthreshold;
541 unsigned int plen;
542
543 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
544 li = li_user;
545 else
546 li = &default_loginfo;
547
548 inst = instance_lookup_get(li->u.ulog.group);
549 if (!inst)
550 return;
551
552 plen = 0;
553 if (prefix)
554 plen = strlen(prefix) + 1;
555
556 /* FIXME: do we want to make the size calculation conditional based on
557 * what is actually present? way more branches and checks, but more
558 * memory efficient... */
559 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
560 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
561 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
562 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
563 #ifdef CONFIG_BRIDGE_NETFILTER
564 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
565 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
566 #endif
567 + nla_total_size(sizeof(u_int32_t)) /* mark */
568 + nla_total_size(sizeof(u_int32_t)) /* uid */
569 + nla_total_size(sizeof(u_int32_t)) /* gid */
570 + nla_total_size(plen) /* prefix */
571 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
572 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
573
574 spin_lock_bh(&inst->lock);
575
576 if (inst->flags & NFULNL_CFG_F_SEQ)
577 size += nla_total_size(sizeof(u_int32_t));
578 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
579 size += nla_total_size(sizeof(u_int32_t));
580
581 qthreshold = inst->qthreshold;
582 /* per-rule qthreshold overrides per-instance */
583 if (qthreshold > li->u.ulog.qthreshold)
584 qthreshold = li->u.ulog.qthreshold;
585
586 switch (inst->copy_mode) {
587 case NFULNL_COPY_META:
588 case NFULNL_COPY_NONE:
589 data_len = 0;
590 break;
591
592 case NFULNL_COPY_PACKET:
593 if (inst->copy_range == 0
594 || inst->copy_range > skb->len)
595 data_len = skb->len;
596 else
597 data_len = inst->copy_range;
598
599 size += nla_total_size(data_len);
600 break;
601
602 default:
603 goto unlock_and_release;
604 }
605
606 if (inst->skb &&
607 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
608 /* either the queue len is too high or we don't have
609 * enough room in the skb left. flush to userspace. */
610 __nfulnl_flush(inst);
611 }
612
613 if (!inst->skb) {
614 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
615 if (!inst->skb)
616 goto alloc_failure;
617 }
618
619 inst->qlen++;
620
621 __build_packet_message(inst, skb, data_len, pf,
622 hooknum, in, out, li, prefix, plen);
623
624 if (inst->qlen >= qthreshold)
625 __nfulnl_flush(inst);
626 /* timer_pending always called within inst->lock, so there
627 * is no chance of a race here */
628 else if (!timer_pending(&inst->timer)) {
629 instance_get(inst);
630 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
631 add_timer(&inst->timer);
632 }
633
634 unlock_and_release:
635 spin_unlock_bh(&inst->lock);
636 instance_put(inst);
637 return;
638
639 alloc_failure:
640 /* FIXME: statistics */
641 goto unlock_and_release;
642 }
643
644 static int
645 nfulnl_rcv_nl_event(struct notifier_block *this,
646 unsigned long event, void *ptr)
647 {
648 struct netlink_notify *n = ptr;
649
650 if (event == NETLINK_URELEASE &&
651 n->protocol == NETLINK_NETFILTER && n->pid) {
652 int i;
653
654 /* destroy all instances for this pid */
655 write_lock_bh(&instances_lock);
656 for (i = 0; i < INSTANCE_BUCKETS; i++) {
657 struct hlist_node *tmp, *t2;
658 struct nfulnl_instance *inst;
659 struct hlist_head *head = &instance_table[i];
660
661 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
662 if ((n->net == &init_net) &&
663 (n->pid == inst->peer_pid))
664 __instance_destroy(inst);
665 }
666 }
667 write_unlock_bh(&instances_lock);
668 }
669 return NOTIFY_DONE;
670 }
671
672 static struct notifier_block nfulnl_rtnl_notifier = {
673 .notifier_call = nfulnl_rcv_nl_event,
674 };
675
676 static int
677 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
678 struct nlmsghdr *nlh, struct nlattr *nfqa[])
679 {
680 return -ENOTSUPP;
681 }
682
683 static const struct nf_logger nfulnl_logger = {
684 .name = "nfnetlink_log",
685 .logfn = &nfulnl_log_packet,
686 .me = THIS_MODULE,
687 };
688
689 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
690 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
691 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
692 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
693 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
694 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
695 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
696 };
697
698 static int
699 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
700 struct nlmsghdr *nlh, struct nlattr *nfula[])
701 {
702 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
703 u_int16_t group_num = ntohs(nfmsg->res_id);
704 struct nfulnl_instance *inst;
705 struct nfulnl_msg_config_cmd *cmd = NULL;
706 int ret = 0;
707
708 if (nfula[NFULA_CFG_CMD]) {
709 u_int8_t pf = nfmsg->nfgen_family;
710 cmd = nla_data(nfula[NFULA_CFG_CMD]);
711
712 /* Commands without queue context */
713 switch (cmd->command) {
714 case NFULNL_CFG_CMD_PF_BIND:
715 return nf_log_register(pf, &nfulnl_logger);
716 case NFULNL_CFG_CMD_PF_UNBIND:
717 nf_log_unregister_pf(pf);
718 return 0;
719 }
720 }
721
722 inst = instance_lookup_get(group_num);
723 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
724 ret = -EPERM;
725 goto out_put;
726 }
727
728 if (cmd != NULL) {
729 switch (cmd->command) {
730 case NFULNL_CFG_CMD_BIND:
731 if (inst) {
732 ret = -EBUSY;
733 goto out_put;
734 }
735
736 inst = instance_create(group_num,
737 NETLINK_CB(skb).pid);
738 if (IS_ERR(inst)) {
739 ret = PTR_ERR(inst);
740 goto out;
741 }
742 break;
743 case NFULNL_CFG_CMD_UNBIND:
744 if (!inst) {
745 ret = -ENODEV;
746 goto out;
747 }
748
749 instance_destroy(inst);
750 goto out;
751 default:
752 ret = -ENOTSUPP;
753 break;
754 }
755 }
756
757 if (nfula[NFULA_CFG_MODE]) {
758 struct nfulnl_msg_config_mode *params;
759 params = nla_data(nfula[NFULA_CFG_MODE]);
760
761 if (!inst) {
762 ret = -ENODEV;
763 goto out;
764 }
765 nfulnl_set_mode(inst, params->copy_mode,
766 ntohl(params->copy_range));
767 }
768
769 if (nfula[NFULA_CFG_TIMEOUT]) {
770 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
771
772 if (!inst) {
773 ret = -ENODEV;
774 goto out;
775 }
776 nfulnl_set_timeout(inst, ntohl(timeout));
777 }
778
779 if (nfula[NFULA_CFG_NLBUFSIZ]) {
780 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
781
782 if (!inst) {
783 ret = -ENODEV;
784 goto out;
785 }
786 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
787 }
788
789 if (nfula[NFULA_CFG_QTHRESH]) {
790 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
791
792 if (!inst) {
793 ret = -ENODEV;
794 goto out;
795 }
796 nfulnl_set_qthresh(inst, ntohl(qthresh));
797 }
798
799 if (nfula[NFULA_CFG_FLAGS]) {
800 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
801
802 if (!inst) {
803 ret = -ENODEV;
804 goto out;
805 }
806 nfulnl_set_flags(inst, ntohs(flags));
807 }
808
809 out_put:
810 instance_put(inst);
811 out:
812 return ret;
813 }
814
815 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
816 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
817 .attr_count = NFULA_MAX, },
818 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
819 .attr_count = NFULA_CFG_MAX,
820 .policy = nfula_cfg_policy },
821 };
822
823 static const struct nfnetlink_subsystem nfulnl_subsys = {
824 .name = "log",
825 .subsys_id = NFNL_SUBSYS_ULOG,
826 .cb_count = NFULNL_MSG_MAX,
827 .cb = nfulnl_cb,
828 };
829
830 #ifdef CONFIG_PROC_FS
831 struct iter_state {
832 unsigned int bucket;
833 };
834
835 static struct hlist_node *get_first(struct iter_state *st)
836 {
837 if (!st)
838 return NULL;
839
840 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
841 if (!hlist_empty(&instance_table[st->bucket]))
842 return instance_table[st->bucket].first;
843 }
844 return NULL;
845 }
846
847 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
848 {
849 h = h->next;
850 while (!h) {
851 if (++st->bucket >= INSTANCE_BUCKETS)
852 return NULL;
853
854 h = instance_table[st->bucket].first;
855 }
856 return h;
857 }
858
859 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
860 {
861 struct hlist_node *head;
862 head = get_first(st);
863
864 if (head)
865 while (pos && (head = get_next(st, head)))
866 pos--;
867 return pos ? NULL : head;
868 }
869
870 static void *seq_start(struct seq_file *seq, loff_t *pos)
871 __acquires(instances_lock)
872 {
873 read_lock_bh(&instances_lock);
874 return get_idx(seq->private, *pos);
875 }
876
877 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
878 {
879 (*pos)++;
880 return get_next(s->private, v);
881 }
882
883 static void seq_stop(struct seq_file *s, void *v)
884 __releases(instances_lock)
885 {
886 read_unlock_bh(&instances_lock);
887 }
888
889 static int seq_show(struct seq_file *s, void *v)
890 {
891 const struct nfulnl_instance *inst = v;
892
893 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
894 inst->group_num,
895 inst->peer_pid, inst->qlen,
896 inst->copy_mode, inst->copy_range,
897 inst->flushtimeout, atomic_read(&inst->use));
898 }
899
900 static const struct seq_operations nful_seq_ops = {
901 .start = seq_start,
902 .next = seq_next,
903 .stop = seq_stop,
904 .show = seq_show,
905 };
906
907 static int nful_open(struct inode *inode, struct file *file)
908 {
909 return seq_open_private(file, &nful_seq_ops,
910 sizeof(struct iter_state));
911 }
912
913 static const struct file_operations nful_file_ops = {
914 .owner = THIS_MODULE,
915 .open = nful_open,
916 .read = seq_read,
917 .llseek = seq_lseek,
918 .release = seq_release_private,
919 };
920
921 #endif /* PROC_FS */
922
923 static int __init nfnetlink_log_init(void)
924 {
925 int i, status = -ENOMEM;
926
927 for (i = 0; i < INSTANCE_BUCKETS; i++)
928 INIT_HLIST_HEAD(&instance_table[i]);
929
930 /* it's not really all that important to have a random value, so
931 * we can do this from the init function, even if there hasn't
932 * been that much entropy yet */
933 get_random_bytes(&hash_init, sizeof(hash_init));
934
935 netlink_register_notifier(&nfulnl_rtnl_notifier);
936 status = nfnetlink_subsys_register(&nfulnl_subsys);
937 if (status < 0) {
938 printk(KERN_ERR "log: failed to create netlink socket\n");
939 goto cleanup_netlink_notifier;
940 }
941
942 #ifdef CONFIG_PROC_FS
943 if (!proc_create("nfnetlink_log", 0440,
944 proc_net_netfilter, &nful_file_ops))
945 goto cleanup_subsys;
946 #endif
947 return status;
948
949 #ifdef CONFIG_PROC_FS
950 cleanup_subsys:
951 nfnetlink_subsys_unregister(&nfulnl_subsys);
952 #endif
953 cleanup_netlink_notifier:
954 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
955 return status;
956 }
957
958 static void __exit nfnetlink_log_fini(void)
959 {
960 nf_log_unregister(&nfulnl_logger);
961 #ifdef CONFIG_PROC_FS
962 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
963 #endif
964 nfnetlink_subsys_unregister(&nfulnl_subsys);
965 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
966 }
967
968 MODULE_DESCRIPTION("netfilter userspace logging");
969 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
970 MODULE_LICENSE("GPL");
971 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
972
973 module_init(nfnetlink_log_init);
974 module_exit(nfnetlink_log_fini);
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