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ARM: 7409/1: Do not call flush_cache_user_range with mmap_sem held
[linux/fpc-iii.git] / net / netfilter / nfnetlink_log.c
blob2e7ccbb43ddb563b7491eafe197ec0e91d8c4b4b
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 <asm/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 pr_notice("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
311 inst_size);
312
313 if (n > pkt_size) {
314 /* try to allocate only as much as we need for current
315 * packet */
316
317 skb = alloc_skb(pkt_size, GFP_ATOMIC);
318 if (!skb)
319 pr_err("nfnetlink_log: can't even alloc %u "
320 "bytes\n", pkt_size);
321 }
322 }
323
324 return skb;
325 }
326
327 static int
328 __nfulnl_send(struct nfulnl_instance *inst)
329 {
330 int status = -1;
331
332 if (inst->qlen > 1)
333 NLMSG_PUT(inst->skb, 0, 0,
334 NLMSG_DONE,
335 sizeof(struct nfgenmsg));
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
343 nlmsg_failure:
344 return status;
345 }
346
347 static void
348 __nfulnl_flush(struct nfulnl_instance *inst)
349 {
350 /* timer holds a reference */
351 if (del_timer(&inst->timer))
352 instance_put(inst);
353 if (inst->skb)
354 __nfulnl_send(inst);
355 }
356
357 static void
358 nfulnl_timer(unsigned long data)
359 {
360 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
361
362 spin_lock_bh(&inst->lock);
363 if (inst->skb)
364 __nfulnl_send(inst);
365 spin_unlock_bh(&inst->lock);
366 instance_put(inst);
367 }
368
369 /* This is an inline function, we don't really care about a long
370 * list of arguments */
371 static inline int
372 __build_packet_message(struct nfulnl_instance *inst,
373 const struct sk_buff *skb,
374 unsigned int data_len,
375 u_int8_t pf,
376 unsigned int hooknum,
377 const struct net_device *indev,
378 const struct net_device *outdev,
379 const char *prefix, unsigned int plen)
380 {
381 struct nfulnl_msg_packet_hdr pmsg;
382 struct nlmsghdr *nlh;
383 struct nfgenmsg *nfmsg;
384 sk_buff_data_t old_tail = inst->skb->tail;
385
386 nlh = NLMSG_PUT(inst->skb, 0, 0,
387 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
388 sizeof(struct nfgenmsg));
389 nfmsg = NLMSG_DATA(nlh);
390 nfmsg->nfgen_family = pf;
391 nfmsg->version = NFNETLINK_V0;
392 nfmsg->res_id = htons(inst->group_num);
393
394 pmsg.hw_protocol = skb->protocol;
395 pmsg.hook = hooknum;
396
397 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
398
399 if (prefix)
400 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
401
402 if (indev) {
403 #ifndef CONFIG_BRIDGE_NETFILTER
404 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
405 htonl(indev->ifindex));
406 #else
407 if (pf == PF_BRIDGE) {
408 /* Case 1: outdev is physical input device, we need to
409 * look for bridge group (when called from
410 * netfilter_bridge) */
411 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
412 htonl(indev->ifindex));
413 /* this is the bridge group "brX" */
414 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
415 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
416 htonl(br_port_get_rcu(indev)->br->dev->ifindex));
417 } else {
418 /* Case 2: indev is bridge group, we need to look for
419 * physical device (when called from ipv4) */
420 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV,
421 htonl(indev->ifindex));
422 if (skb->nf_bridge && skb->nf_bridge->physindev)
423 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
424 htonl(skb->nf_bridge->physindev->ifindex));
425 }
426 #endif
427 }
428
429 if (outdev) {
430 #ifndef CONFIG_BRIDGE_NETFILTER
431 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
432 htonl(outdev->ifindex));
433 #else
434 if (pf == PF_BRIDGE) {
435 /* Case 1: outdev is physical output device, we need to
436 * look for bridge group (when called from
437 * netfilter_bridge) */
438 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
439 htonl(outdev->ifindex));
440 /* this is the bridge group "brX" */
441 /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
442 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
443 htonl(br_port_get_rcu(outdev)->br->dev->ifindex));
444 } else {
445 /* Case 2: indev is a bridge group, we need to look
446 * for physical device (when called from ipv4) */
447 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV,
448 htonl(outdev->ifindex));
449 if (skb->nf_bridge && skb->nf_bridge->physoutdev)
450 NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
451 htonl(skb->nf_bridge->physoutdev->ifindex));
452 }
453 #endif
454 }
455
456 if (skb->mark)
457 NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark));
458
459 if (indev && skb->dev &&
460 skb->mac_header != skb->network_header) {
461 struct nfulnl_msg_packet_hw phw;
462 int len = dev_parse_header(skb, phw.hw_addr);
463 if (len > 0) {
464 phw.hw_addrlen = htons(len);
465 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
466 }
467 }
468
469 if (indev && skb_mac_header_was_set(skb)) {
470 NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type));
471 NLA_PUT_BE16(inst->skb, NFULA_HWLEN,
472 htons(skb->dev->hard_header_len));
473 NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len,
474 skb_mac_header(skb));
475 }
476
477 if (skb->tstamp.tv64) {
478 struct nfulnl_msg_packet_timestamp ts;
479 struct timeval tv = ktime_to_timeval(skb->tstamp);
480 ts.sec = cpu_to_be64(tv.tv_sec);
481 ts.usec = cpu_to_be64(tv.tv_usec);
482
483 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
484 }
485
486 /* UID */
487 if (skb->sk) {
488 read_lock_bh(&skb->sk->sk_callback_lock);
489 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
490 struct file *file = skb->sk->sk_socket->file;
491 __be32 uid = htonl(file->f_cred->fsuid);
492 __be32 gid = htonl(file->f_cred->fsgid);
493 /* need to unlock here since NLA_PUT may goto */
494 read_unlock_bh(&skb->sk->sk_callback_lock);
495 NLA_PUT_BE32(inst->skb, NFULA_UID, uid);
496 NLA_PUT_BE32(inst->skb, NFULA_GID, gid);
497 } else
498 read_unlock_bh(&skb->sk->sk_callback_lock);
499 }
500
501 /* local sequence number */
502 if (inst->flags & NFULNL_CFG_F_SEQ)
503 NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++));
504
505 /* global sequence number */
506 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
507 NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL,
508 htonl(atomic_inc_return(&global_seq)));
509
510 if (data_len) {
511 struct nlattr *nla;
512 int size = nla_attr_size(data_len);
513
514 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
515 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
516 goto nlmsg_failure;
517 }
518
519 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
520 nla->nla_type = NFULA_PAYLOAD;
521 nla->nla_len = size;
522
523 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
524 BUG();
525 }
526
527 nlh->nlmsg_len = inst->skb->tail - old_tail;
528 return 0;
529
530 nlmsg_failure:
531 nla_put_failure:
532 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
533 return -1;
534 }
535
536 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
537
538 static struct nf_loginfo default_loginfo = {
539 .type = NF_LOG_TYPE_ULOG,
540 .u = {
541 .ulog = {
542 .copy_len = 0xffff,
543 .group = 0,
544 .qthreshold = 1,
545 },
546 },
547 };
548
549 /* log handler for internal netfilter logging api */
550 void
551 nfulnl_log_packet(u_int8_t pf,
552 unsigned int hooknum,
553 const struct sk_buff *skb,
554 const struct net_device *in,
555 const struct net_device *out,
556 const struct nf_loginfo *li_user,
557 const char *prefix)
558 {
559 unsigned int size, data_len;
560 struct nfulnl_instance *inst;
561 const struct nf_loginfo *li;
562 unsigned int qthreshold;
563 unsigned int plen;
564
565 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
566 li = li_user;
567 else
568 li = &default_loginfo;
569
570 inst = instance_lookup_get(li->u.ulog.group);
571 if (!inst)
572 return;
573
574 plen = 0;
575 if (prefix)
576 plen = strlen(prefix) + 1;
577
578 /* FIXME: do we want to make the size calculation conditional based on
579 * what is actually present? way more branches and checks, but more
580 * memory efficient... */
581 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
582 + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
583 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
584 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
585 #ifdef CONFIG_BRIDGE_NETFILTER
586 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
587 + nla_total_size(sizeof(u_int32_t)) /* ifindex */
588 #endif
589 + nla_total_size(sizeof(u_int32_t)) /* mark */
590 + nla_total_size(sizeof(u_int32_t)) /* uid */
591 + nla_total_size(sizeof(u_int32_t)) /* gid */
592 + nla_total_size(plen) /* prefix */
593 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
594 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
595
596 if (in && skb_mac_header_was_set(skb)) {
597 size += nla_total_size(skb->dev->hard_header_len)
598 + nla_total_size(sizeof(u_int16_t)) /* hwtype */
599 + nla_total_size(sizeof(u_int16_t)); /* hwlen */
600 }
601
602 spin_lock_bh(&inst->lock);
603
604 if (inst->flags & NFULNL_CFG_F_SEQ)
605 size += nla_total_size(sizeof(u_int32_t));
606 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
607 size += nla_total_size(sizeof(u_int32_t));
608
609 qthreshold = inst->qthreshold;
610 /* per-rule qthreshold overrides per-instance */
611 if (li->u.ulog.qthreshold)
612 if (qthreshold > li->u.ulog.qthreshold)
613 qthreshold = li->u.ulog.qthreshold;
614
615
616 switch (inst->copy_mode) {
617 case NFULNL_COPY_META:
618 case NFULNL_COPY_NONE:
619 data_len = 0;
620 break;
621
622 case NFULNL_COPY_PACKET:
623 if (inst->copy_range == 0
624 || inst->copy_range > skb->len)
625 data_len = skb->len;
626 else
627 data_len = inst->copy_range;
628
629 size += nla_total_size(data_len);
630 break;
631
632 case NFULNL_COPY_DISABLED:
633 default:
634 goto unlock_and_release;
635 }
636
637 if (inst->skb &&
638 size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) {
639 /* either the queue len is too high or we don't have
640 * enough room in the skb left. flush to userspace. */
641 __nfulnl_flush(inst);
642 }
643
644 if (!inst->skb) {
645 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
646 if (!inst->skb)
647 goto alloc_failure;
648 }
649
650 inst->qlen++;
651
652 __build_packet_message(inst, skb, data_len, pf,
653 hooknum, in, out, prefix, plen);
654
655 if (inst->qlen >= qthreshold)
656 __nfulnl_flush(inst);
657 /* timer_pending always called within inst->lock, so there
658 * is no chance of a race here */
659 else if (!timer_pending(&inst->timer)) {
660 instance_get(inst);
661 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
662 add_timer(&inst->timer);
663 }
664
665 unlock_and_release:
666 spin_unlock_bh(&inst->lock);
667 instance_put(inst);
668 return;
669
670 alloc_failure:
671 /* FIXME: statistics */
672 goto unlock_and_release;
673 }
674 EXPORT_SYMBOL_GPL(nfulnl_log_packet);
675
676 static int
677 nfulnl_rcv_nl_event(struct notifier_block *this,
678 unsigned long event, void *ptr)
679 {
680 struct netlink_notify *n = ptr;
681
682 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
683 int i;
684
685 /* destroy all instances for this pid */
686 spin_lock_bh(&instances_lock);
687 for (i = 0; i < INSTANCE_BUCKETS; i++) {
688 struct hlist_node *tmp, *t2;
689 struct nfulnl_instance *inst;
690 struct hlist_head *head = &instance_table[i];
691
692 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
693 if ((net_eq(n->net, &init_net)) &&
694 (n->pid == inst->peer_pid))
695 __instance_destroy(inst);
696 }
697 }
698 spin_unlock_bh(&instances_lock);
699 }
700 return NOTIFY_DONE;
701 }
702
703 static struct notifier_block nfulnl_rtnl_notifier = {
704 .notifier_call = nfulnl_rcv_nl_event,
705 };
706
707 static int
708 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
709 const struct nlmsghdr *nlh,
710 const struct nlattr * const nfqa[])
711 {
712 return -ENOTSUPP;
713 }
714
715 static struct nf_logger nfulnl_logger __read_mostly = {
716 .name = "nfnetlink_log",
717 .logfn = &nfulnl_log_packet,
718 .me = THIS_MODULE,
719 };
720
721 static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
722 [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
723 [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
724 [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
725 [NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
726 [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
727 [NFULA_CFG_FLAGS] = { .type = NLA_U16 },
728 };
729
730 static int
731 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
732 const struct nlmsghdr *nlh,
733 const struct nlattr * const nfula[])
734 {
735 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
736 u_int16_t group_num = ntohs(nfmsg->res_id);
737 struct nfulnl_instance *inst;
738 struct nfulnl_msg_config_cmd *cmd = NULL;
739 int ret = 0;
740
741 if (nfula[NFULA_CFG_CMD]) {
742 u_int8_t pf = nfmsg->nfgen_family;
743 cmd = nla_data(nfula[NFULA_CFG_CMD]);
744
745 /* Commands without queue context */
746 switch (cmd->command) {
747 case NFULNL_CFG_CMD_PF_BIND:
748 return nf_log_bind_pf(pf, &nfulnl_logger);
749 case NFULNL_CFG_CMD_PF_UNBIND:
750 nf_log_unbind_pf(pf);
751 return 0;
752 }
753 }
754
755 inst = instance_lookup_get(group_num);
756 if (inst && inst->peer_pid != NETLINK_CB(skb).pid) {
757 ret = -EPERM;
758 goto out_put;
759 }
760
761 if (cmd != NULL) {
762 switch (cmd->command) {
763 case NFULNL_CFG_CMD_BIND:
764 if (inst) {
765 ret = -EBUSY;
766 goto out_put;
767 }
768
769 inst = instance_create(group_num,
770 NETLINK_CB(skb).pid);
771 if (IS_ERR(inst)) {
772 ret = PTR_ERR(inst);
773 goto out;
774 }
775 break;
776 case NFULNL_CFG_CMD_UNBIND:
777 if (!inst) {
778 ret = -ENODEV;
779 goto out;
780 }
781
782 instance_destroy(inst);
783 goto out_put;
784 default:
785 ret = -ENOTSUPP;
786 break;
787 }
788 }
789
790 if (nfula[NFULA_CFG_MODE]) {
791 struct nfulnl_msg_config_mode *params;
792 params = nla_data(nfula[NFULA_CFG_MODE]);
793
794 if (!inst) {
795 ret = -ENODEV;
796 goto out;
797 }
798 nfulnl_set_mode(inst, params->copy_mode,
799 ntohl(params->copy_range));
800 }
801
802 if (nfula[NFULA_CFG_TIMEOUT]) {
803 __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
804
805 if (!inst) {
806 ret = -ENODEV;
807 goto out;
808 }
809 nfulnl_set_timeout(inst, ntohl(timeout));
810 }
811
812 if (nfula[NFULA_CFG_NLBUFSIZ]) {
813 __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
814
815 if (!inst) {
816 ret = -ENODEV;
817 goto out;
818 }
819 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
820 }
821
822 if (nfula[NFULA_CFG_QTHRESH]) {
823 __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
824
825 if (!inst) {
826 ret = -ENODEV;
827 goto out;
828 }
829 nfulnl_set_qthresh(inst, ntohl(qthresh));
830 }
831
832 if (nfula[NFULA_CFG_FLAGS]) {
833 __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
834
835 if (!inst) {
836 ret = -ENODEV;
837 goto out;
838 }
839 nfulnl_set_flags(inst, ntohs(flags));
840 }
841
842 out_put:
843 instance_put(inst);
844 out:
845 return ret;
846 }
847
848 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
849 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
850 .attr_count = NFULA_MAX, },
851 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
852 .attr_count = NFULA_CFG_MAX,
853 .policy = nfula_cfg_policy },
854 };
855
856 static const struct nfnetlink_subsystem nfulnl_subsys = {
857 .name = "log",
858 .subsys_id = NFNL_SUBSYS_ULOG,
859 .cb_count = NFULNL_MSG_MAX,
860 .cb = nfulnl_cb,
861 };
862
863 #ifdef CONFIG_PROC_FS
864 struct iter_state {
865 unsigned int bucket;
866 };
867
868 static struct hlist_node *get_first(struct iter_state *st)
869 {
870 if (!st)
871 return NULL;
872
873 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
874 if (!hlist_empty(&instance_table[st->bucket]))
875 return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
876 }
877 return NULL;
878 }
879
880 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
881 {
882 h = rcu_dereference_bh(hlist_next_rcu(h));
883 while (!h) {
884 if (++st->bucket >= INSTANCE_BUCKETS)
885 return NULL;
886
887 h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
888 }
889 return h;
890 }
891
892 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
893 {
894 struct hlist_node *head;
895 head = get_first(st);
896
897 if (head)
898 while (pos && (head = get_next(st, head)))
899 pos--;
900 return pos ? NULL : head;
901 }
902
903 static void *seq_start(struct seq_file *seq, loff_t *pos)
904 __acquires(rcu_bh)
905 {
906 rcu_read_lock_bh();
907 return get_idx(seq->private, *pos);
908 }
909
910 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
911 {
912 (*pos)++;
913 return get_next(s->private, v);
914 }
915
916 static void seq_stop(struct seq_file *s, void *v)
917 __releases(rcu_bh)
918 {
919 rcu_read_unlock_bh();
920 }
921
922 static int seq_show(struct seq_file *s, void *v)
923 {
924 const struct nfulnl_instance *inst = v;
925
926 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
927 inst->group_num,
928 inst->peer_pid, inst->qlen,
929 inst->copy_mode, inst->copy_range,
930 inst->flushtimeout, atomic_read(&inst->use));
931 }
932
933 static const struct seq_operations nful_seq_ops = {
934 .start = seq_start,
935 .next = seq_next,
936 .stop = seq_stop,
937 .show = seq_show,
938 };
939
940 static int nful_open(struct inode *inode, struct file *file)
941 {
942 return seq_open_private(file, &nful_seq_ops,
943 sizeof(struct iter_state));
944 }
945
946 static const struct file_operations nful_file_ops = {
947 .owner = THIS_MODULE,
948 .open = nful_open,
949 .read = seq_read,
950 .llseek = seq_lseek,
951 .release = seq_release_private,
952 };
953
954 #endif /* PROC_FS */
955
956 static int __init nfnetlink_log_init(void)
957 {
958 int i, status = -ENOMEM;
959
960 for (i = 0; i < INSTANCE_BUCKETS; i++)
961 INIT_HLIST_HEAD(&instance_table[i]);
962
963 /* it's not really all that important to have a random value, so
964 * we can do this from the init function, even if there hasn't
965 * been that much entropy yet */
966 get_random_bytes(&hash_init, sizeof(hash_init));
967
968 netlink_register_notifier(&nfulnl_rtnl_notifier);
969 status = nfnetlink_subsys_register(&nfulnl_subsys);
970 if (status < 0) {
971 printk(KERN_ERR "log: failed to create netlink socket\n");
972 goto cleanup_netlink_notifier;
973 }
974
975 status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
976 if (status < 0) {
977 printk(KERN_ERR "log: failed to register logger\n");
978 goto cleanup_subsys;
979 }
980
981 #ifdef CONFIG_PROC_FS
982 if (!proc_create("nfnetlink_log", 0440,
983 proc_net_netfilter, &nful_file_ops))
984 goto cleanup_logger;
985 #endif
986 return status;
987
988 #ifdef CONFIG_PROC_FS
989 cleanup_logger:
990 nf_log_unregister(&nfulnl_logger);
991 #endif
992 cleanup_subsys:
993 nfnetlink_subsys_unregister(&nfulnl_subsys);
994 cleanup_netlink_notifier:
995 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
996 return status;
997 }
998
999 static void __exit nfnetlink_log_fini(void)
1000 {
1001 nf_log_unregister(&nfulnl_logger);
1002 #ifdef CONFIG_PROC_FS
1003 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1004 #endif
1005 nfnetlink_subsys_unregister(&nfulnl_subsys);
1006 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1007 }
1008
1009 MODULE_DESCRIPTION("netfilter userspace logging");
1010 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1011 MODULE_LICENSE("GPL");
1012 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1013
1014 module_init(nfnetlink_log_init);
1015 module_exit(nfnetlink_log_fini);
Linux with added FPC-III support