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[NETFILTER]: nfnetlink: convert to generic netlink attribute functions
[deliverable/linux.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 <net/sock.h>
32
33 #include <asm/atomic.h>
34
35 #ifdef CONFIG_BRIDGE_NETFILTER
36 #include "../bridge/br_private.h"
37 #endif
38
39 #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
40 #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
41 #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
42
43 #define PRINTR(x, args...) do { if (net_ratelimit()) \
44 printk(x, ## args); } while (0);
45
46 #if 0
47 #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
48 __FILE__, __LINE__, __FUNCTION__, \
49 ## args)
50 #else
51 #define UDEBUG(x, ...)
52 #endif
53
54 struct nfulnl_instance {
55 struct hlist_node hlist; /* global list of instances */
56 spinlock_t lock;
57 atomic_t use; /* use count */
58
59 unsigned int qlen; /* number of nlmsgs in skb */
60 struct sk_buff *skb; /* pre-allocatd skb */
61 struct timer_list timer;
62 int peer_pid; /* PID of the peer process */
63
64 /* configurable parameters */
65 unsigned int flushtimeout; /* timeout until queue flush */
66 unsigned int nlbufsiz; /* netlink buffer allocation size */
67 unsigned int qthreshold; /* threshold of the queue */
68 u_int32_t copy_range;
69 u_int32_t seq; /* instance-local sequential counter */
70 u_int16_t group_num; /* number of this queue */
71 u_int16_t flags;
72 u_int8_t copy_mode;
73 };
74
75 static DEFINE_RWLOCK(instances_lock);
76 static atomic_t global_seq;
77
78 #define INSTANCE_BUCKETS 16
79 static struct hlist_head instance_table[INSTANCE_BUCKETS];
80 static unsigned int hash_init;
81
82 static inline u_int8_t instance_hashfn(u_int16_t group_num)
83 {
84 return ((group_num & 0xff) % INSTANCE_BUCKETS);
85 }
86
87 static struct nfulnl_instance *
88 __instance_lookup(u_int16_t group_num)
89 {
90 struct hlist_head *head;
91 struct hlist_node *pos;
92 struct nfulnl_instance *inst;
93
94 UDEBUG("entering (group_num=%u)\n", group_num);
95
96 head = &instance_table[instance_hashfn(group_num)];
97 hlist_for_each_entry(inst, pos, head, hlist) {
98 if (inst->group_num == group_num)
99 return inst;
100 }
101 return NULL;
102 }
103
104 static inline void
105 instance_get(struct nfulnl_instance *inst)
106 {
107 atomic_inc(&inst->use);
108 }
109
110 static struct nfulnl_instance *
111 instance_lookup_get(u_int16_t group_num)
112 {
113 struct nfulnl_instance *inst;
114
115 read_lock_bh(&instances_lock);
116 inst = __instance_lookup(group_num);
117 if (inst)
118 instance_get(inst);
119 read_unlock_bh(&instances_lock);
120
121 return inst;
122 }
123
124 static void
125 instance_put(struct nfulnl_instance *inst)
126 {
127 if (inst && atomic_dec_and_test(&inst->use)) {
128 UDEBUG("kfree(inst=%p)\n", inst);
129 kfree(inst);
130 module_put(THIS_MODULE);
131 }
132 }
133
134 static void nfulnl_timer(unsigned long data);
135
136 static struct nfulnl_instance *
137 instance_create(u_int16_t group_num, int pid)
138 {
139 struct nfulnl_instance *inst;
140
141 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
142 pid);
143
144 write_lock_bh(&instances_lock);
145 if (__instance_lookup(group_num)) {
146 inst = NULL;
147 UDEBUG("aborting, instance already exists\n");
148 goto out_unlock;
149 }
150
151 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
152 if (!inst)
153 goto out_unlock;
154
155 INIT_HLIST_NODE(&inst->hlist);
156 spin_lock_init(&inst->lock);
157 /* needs to be two, since we _put() after creation */
158 atomic_set(&inst->use, 2);
159
160 setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
161
162 inst->peer_pid = pid;
163 inst->group_num = group_num;
164
165 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
166 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
167 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
168 inst->copy_mode = NFULNL_COPY_PACKET;
169 inst->copy_range = 0xffff;
170
171 if (!try_module_get(THIS_MODULE))
172 goto out_free;
173
174 hlist_add_head(&inst->hlist,
175 &instance_table[instance_hashfn(group_num)]);
176
177 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
178 inst->hlist.next);
179
180 write_unlock_bh(&instances_lock);
181
182 return inst;
183
184 out_free:
185 instance_put(inst);
186 out_unlock:
187 write_unlock_bh(&instances_lock);
188 return NULL;
189 }
190
191 static int __nfulnl_send(struct nfulnl_instance *inst);
192
193 static void
194 __instance_destroy(struct nfulnl_instance *inst)
195 {
196 /* first pull it out of the global list */
197 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
198 inst, inst->group_num);
199
200 hlist_del(&inst->hlist);
201
202 /* then flush all pending packets from skb */
203
204 spin_lock_bh(&inst->lock);
205 if (inst->skb) {
206 /* timer "holds" one reference (we have one more) */
207 if (del_timer(&inst->timer))
208 instance_put(inst);
209 if (inst->qlen)
210 __nfulnl_send(inst);
211 if (inst->skb) {
212 kfree_skb(inst->skb);
213 inst->skb = NULL;
214 }
215 }
216 spin_unlock_bh(&inst->lock);
217
218 /* and finally put the refcount */
219 instance_put(inst);
220 }
221
222 static inline void
223 instance_destroy(struct nfulnl_instance *inst)
224 {
225 write_lock_bh(&instances_lock);
226 __instance_destroy(inst);
227 write_unlock_bh(&instances_lock);
228 }
229
230 static int
231 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
232 unsigned int range)
233 {
234 int status = 0;
235
236 spin_lock_bh(&inst->lock);
237
238 switch (mode) {
239 case NFULNL_COPY_NONE:
240 case NFULNL_COPY_META:
241 inst->copy_mode = mode;
242 inst->copy_range = 0;
243 break;
244
245 case NFULNL_COPY_PACKET:
246 inst->copy_mode = mode;
247 /* we're using struct nlattr which has 16bit nfa_len */
248 if (range > 0xffff)
249 inst->copy_range = 0xffff;
250 else
251 inst->copy_range = range;
252 break;
253
254 default:
255 status = -EINVAL;
256 break;
257 }
258
259 spin_unlock_bh(&inst->lock);
260
261 return status;
262 }
263
264 static int
265 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
266 {
267 int status;
268
269 spin_lock_bh(&inst->lock);
270 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
271 status = -ERANGE;
272 else if (nlbufsiz > 131072)
273 status = -ERANGE;
274 else {
275 inst->nlbufsiz = nlbufsiz;
276 status = 0;
277 }
278 spin_unlock_bh(&inst->lock);
279
280 return status;
281 }
282
283 static int
284 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
285 {
286 spin_lock_bh(&inst->lock);
287 inst->flushtimeout = timeout;
288 spin_unlock_bh(&inst->lock);
289
290 return 0;
291 }
292
293 static int
294 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
295 {
296 spin_lock_bh(&inst->lock);
297 inst->qthreshold = qthresh;
298 spin_unlock_bh(&inst->lock);
299
300 return 0;
301 }
302
303 static int
304 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
305 {
306 spin_lock_bh(&inst->lock);
307 inst->flags = flags;
308 spin_unlock_bh(&inst->lock);
309
310 return 0;
311 }
312
313 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
314 unsigned int pkt_size)
315 {
316 struct sk_buff *skb;
317 unsigned int n;
318
319 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
320
321 /* alloc skb which should be big enough for a whole multipart
322 * message. WARNING: has to be <= 128k due to slab restrictions */
323
324 n = max(inst_size, pkt_size);
325 skb = alloc_skb(n, GFP_ATOMIC);
326 if (!skb) {
327 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
328 inst_size);
329
330 if (n > pkt_size) {
331 /* try to allocate only as much as we need for current
332 * packet */
333
334 skb = alloc_skb(pkt_size, GFP_ATOMIC);
335 if (!skb)
336 PRINTR("nfnetlink_log: can't even alloc %u "
337 "bytes\n", pkt_size);
338 }
339 }
340
341 return skb;
342 }
343
344 static int
345 __nfulnl_send(struct nfulnl_instance *inst)
346 {
347 int status = -1;
348
349 if (inst->qlen > 1)
350 NLMSG_PUT(inst->skb, 0, 0,
351 NLMSG_DONE,
352 sizeof(struct nfgenmsg));
353
354 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
355 if (status < 0) {
356 UDEBUG("netlink_unicast() failed\n");
357 /* FIXME: statistics */
358 }
359
360 inst->qlen = 0;
361 inst->skb = NULL;
362
363 nlmsg_failure:
364 return status;
365 }
366
367 static void nfulnl_timer(unsigned long data)
368 {
369 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
370
371 UDEBUG("timer function called, flushing buffer\n");
372
373 spin_lock_bh(&inst->lock);
374 if (inst->skb)
375 __nfulnl_send(inst);
376 spin_unlock_bh(&inst->lock);
377 instance_put(inst);
378 }
379
380 /* This is an inline function, we don't really care about a long
381 * list of arguments */
382 static inline int
383 __build_packet_message(struct nfulnl_instance *inst,
384 const struct sk_buff *skb,
385 unsigned int data_len,
386 unsigned int pf,
387 unsigned int hooknum,
388 const struct net_device *indev,
389 const struct net_device *outdev,
390 const struct nf_loginfo *li,
391 const char *prefix, unsigned int plen)
392 {
393 struct nfulnl_msg_packet_hdr pmsg;
394 struct nlmsghdr *nlh;
395 struct nfgenmsg *nfmsg;
396 __be32 tmp_uint;
397 sk_buff_data_t old_tail = inst->skb->tail;
398
399 UDEBUG("entered\n");
400
401 nlh = NLMSG_PUT(inst->skb, 0, 0,
402 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
403 sizeof(struct nfgenmsg));
404 nfmsg = NLMSG_DATA(nlh);
405 nfmsg->nfgen_family = pf;
406 nfmsg->version = NFNETLINK_V0;
407 nfmsg->res_id = htons(inst->group_num);
408
409 pmsg.hw_protocol = skb->protocol;
410 pmsg.hook = hooknum;
411
412 NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
413
414 if (prefix)
415 NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
416
417 if (indev) {
418 tmp_uint = htonl(indev->ifindex);
419 #ifndef CONFIG_BRIDGE_NETFILTER
420 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
421 &tmp_uint);
422 #else
423 if (pf == PF_BRIDGE) {
424 /* Case 1: outdev is physical input device, we need to
425 * look for bridge group (when called from
426 * netfilter_bridge) */
427 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
428 sizeof(tmp_uint), &tmp_uint);
429 /* this is the bridge group "brX" */
430 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
431 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
432 sizeof(tmp_uint), &tmp_uint);
433 } else {
434 /* Case 2: indev is bridge group, we need to look for
435 * physical device (when called from ipv4) */
436 NLA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
437 sizeof(tmp_uint), &tmp_uint);
438 if (skb->nf_bridge && skb->nf_bridge->physindev) {
439 tmp_uint =
440 htonl(skb->nf_bridge->physindev->ifindex);
441 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
442 sizeof(tmp_uint), &tmp_uint);
443 }
444 }
445 #endif
446 }
447
448 if (outdev) {
449 tmp_uint = htonl(outdev->ifindex);
450 #ifndef CONFIG_BRIDGE_NETFILTER
451 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
452 &tmp_uint);
453 #else
454 if (pf == PF_BRIDGE) {
455 /* Case 1: outdev is physical output device, we need to
456 * look for bridge group (when called from
457 * netfilter_bridge) */
458 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
459 sizeof(tmp_uint), &tmp_uint);
460 /* this is the bridge group "brX" */
461 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
462 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
463 sizeof(tmp_uint), &tmp_uint);
464 } else {
465 /* Case 2: indev is a bridge group, we need to look
466 * for physical device (when called from ipv4) */
467 NLA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
468 sizeof(tmp_uint), &tmp_uint);
469 if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
470 tmp_uint =
471 htonl(skb->nf_bridge->physoutdev->ifindex);
472 NLA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
473 sizeof(tmp_uint), &tmp_uint);
474 }
475 }
476 #endif
477 }
478
479 if (skb->mark) {
480 tmp_uint = htonl(skb->mark);
481 NLA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
482 }
483
484 if (indev && skb->dev) {
485 struct nfulnl_msg_packet_hw phw;
486 int len = dev_parse_header(skb, phw.hw_addr);
487 if (len > 0) {
488 phw.hw_addrlen = htons(len);
489 NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
490 }
491 }
492
493 if (skb->tstamp.tv64) {
494 struct nfulnl_msg_packet_timestamp ts;
495 struct timeval tv = ktime_to_timeval(skb->tstamp);
496 ts.sec = cpu_to_be64(tv.tv_sec);
497 ts.usec = cpu_to_be64(tv.tv_usec);
498
499 NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
500 }
501
502 /* UID */
503 if (skb->sk) {
504 read_lock_bh(&skb->sk->sk_callback_lock);
505 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
506 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
507 /* need to unlock here since NLA_PUT may goto */
508 read_unlock_bh(&skb->sk->sk_callback_lock);
509 NLA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
510 } else
511 read_unlock_bh(&skb->sk->sk_callback_lock);
512 }
513
514 /* local sequence number */
515 if (inst->flags & NFULNL_CFG_F_SEQ) {
516 tmp_uint = htonl(inst->seq++);
517 NLA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
518 }
519 /* global sequence number */
520 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
521 tmp_uint = htonl(atomic_inc_return(&global_seq));
522 NLA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
523 }
524
525 if (data_len) {
526 struct nlattr *nla;
527 int size = nla_attr_size(data_len);
528
529 if (skb_tailroom(inst->skb) < nla_total_size(data_len)) {
530 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
531 goto nlmsg_failure;
532 }
533
534 nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
535 nla->nla_type = NFULA_PAYLOAD;
536 nla->nla_len = size;
537
538 if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
539 BUG();
540 }
541
542 nlh->nlmsg_len = inst->skb->tail - old_tail;
543 return 0;
544
545 nlmsg_failure:
546 UDEBUG("nlmsg_failure\n");
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 static void
567 nfulnl_log_packet(unsigned int 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_ALIGN(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(plen) /* prefix */
608 + nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
609 + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp));
610
611 UDEBUG("initial size=%u\n", size);
612
613 spin_lock_bh(&inst->lock);
614
615 if (inst->flags & NFULNL_CFG_F_SEQ)
616 size += nla_total_size(sizeof(u_int32_t));
617 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
618 size += nla_total_size(sizeof(u_int32_t));
619
620 qthreshold = inst->qthreshold;
621 /* per-rule qthreshold overrides per-instance */
622 if (qthreshold > li->u.ulog.qthreshold)
623 qthreshold = li->u.ulog.qthreshold;
624
625 switch (inst->copy_mode) {
626 case NFULNL_COPY_META:
627 case NFULNL_COPY_NONE:
628 data_len = 0;
629 break;
630
631 case NFULNL_COPY_PACKET:
632 if (inst->copy_range == 0
633 || inst->copy_range > skb->len)
634 data_len = skb->len;
635 else
636 data_len = inst->copy_range;
637
638 size += nla_total_size(data_len);
639 UDEBUG("copy_packet, therefore size now %u\n", size);
640 break;
641
642 default:
643 goto unlock_and_release;
644 }
645
646 if (inst->qlen >= qthreshold ||
647 (inst->skb && size >
648 skb_tailroom(inst->skb) - sizeof(struct nfgenmsg))) {
649 /* either the queue len is too high or we don't have
650 * enough room in the skb left. flush to userspace. */
651 UDEBUG("flushing old skb\n");
652
653 /* timer "holds" one reference (we have another one) */
654 if (del_timer(&inst->timer))
655 instance_put(inst);
656 __nfulnl_send(inst);
657 }
658
659 if (!inst->skb) {
660 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
661 if (!inst->skb)
662 goto alloc_failure;
663 }
664
665 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
666 inst->qlen++;
667
668 __build_packet_message(inst, skb, data_len, pf,
669 hooknum, in, out, li, prefix, plen);
670
671 /* timer_pending always called within inst->lock, so there
672 * is no chance of a race here */
673 if (!timer_pending(&inst->timer)) {
674 instance_get(inst);
675 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
676 add_timer(&inst->timer);
677 }
678
679 unlock_and_release:
680 spin_unlock_bh(&inst->lock);
681 instance_put(inst);
682 return;
683
684 alloc_failure:
685 UDEBUG("error allocating skb\n");
686 /* FIXME: statistics */
687 goto unlock_and_release;
688 }
689
690 static int
691 nfulnl_rcv_nl_event(struct notifier_block *this,
692 unsigned long event, void *ptr)
693 {
694 struct netlink_notify *n = ptr;
695
696 if (event == NETLINK_URELEASE &&
697 n->protocol == NETLINK_NETFILTER && n->pid) {
698 int i;
699
700 /* destroy all instances for this pid */
701 write_lock_bh(&instances_lock);
702 for (i = 0; i < INSTANCE_BUCKETS; i++) {
703 struct hlist_node *tmp, *t2;
704 struct nfulnl_instance *inst;
705 struct hlist_head *head = &instance_table[i];
706
707 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
708 UDEBUG("node = %p\n", inst);
709 if ((n->net == &init_net) &&
710 (n->pid == inst->peer_pid))
711 __instance_destroy(inst);
712 }
713 }
714 write_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 struct nlmsghdr *nlh, struct nlattr *nfqa[])
726 {
727 return -ENOTSUPP;
728 }
729
730 static struct nf_logger nfulnl_logger = {
731 .name = "nfnetlink_log",
732 .logfn = &nfulnl_log_packet,
733 .me = THIS_MODULE,
734 };
735
736 static const int nfula_min[NFULA_MAX+1] = {
737 [NFULA_PACKET_HDR] = sizeof(struct nfulnl_msg_packet_hdr),
738 [NFULA_MARK] = sizeof(u_int32_t),
739 [NFULA_TIMESTAMP] = sizeof(struct nfulnl_msg_packet_timestamp),
740 [NFULA_IFINDEX_INDEV] = sizeof(u_int32_t),
741 [NFULA_IFINDEX_OUTDEV] = sizeof(u_int32_t),
742 [NFULA_IFINDEX_PHYSINDEV] = sizeof(u_int32_t),
743 [NFULA_IFINDEX_PHYSOUTDEV] = sizeof(u_int32_t),
744 [NFULA_HWADDR] = sizeof(struct nfulnl_msg_packet_hw),
745 [NFULA_PAYLOAD] = 0,
746 [NFULA_PREFIX] = 0,
747 [NFULA_UID] = sizeof(u_int32_t),
748 [NFULA_SEQ] = sizeof(u_int32_t),
749 [NFULA_SEQ_GLOBAL] = sizeof(u_int32_t),
750 };
751
752 static const int nfula_cfg_min[NFULA_CFG_MAX+1] = {
753 [NFULA_CFG_CMD] = sizeof(struct nfulnl_msg_config_cmd),
754 [NFULA_CFG_MODE] = sizeof(struct nfulnl_msg_config_mode),
755 [NFULA_CFG_TIMEOUT] = sizeof(u_int32_t),
756 [NFULA_CFG_QTHRESH] = sizeof(u_int32_t),
757 [NFULA_CFG_NLBUFSIZ] = sizeof(u_int32_t),
758 [NFULA_CFG_FLAGS] = sizeof(u_int16_t),
759 };
760
761 static int
762 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
763 struct nlmsghdr *nlh, struct nlattr *nfula[])
764 {
765 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
766 u_int16_t group_num = ntohs(nfmsg->res_id);
767 struct nfulnl_instance *inst;
768 int ret = 0;
769
770 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
771
772 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
773 UDEBUG("bad attribute size\n");
774 return -EINVAL;
775 }
776
777 inst = instance_lookup_get(group_num);
778 if (nfula[NFULA_CFG_CMD]) {
779 u_int8_t pf = nfmsg->nfgen_family;
780 struct nfulnl_msg_config_cmd *cmd;
781 cmd = nla_data(nfula[NFULA_CFG_CMD]);
782 UDEBUG("found CFG_CMD for\n");
783
784 switch (cmd->command) {
785 case NFULNL_CFG_CMD_BIND:
786 if (inst) {
787 ret = -EBUSY;
788 goto out_put;
789 }
790
791 inst = instance_create(group_num,
792 NETLINK_CB(skb).pid);
793 if (!inst) {
794 ret = -EINVAL;
795 goto out;
796 }
797 break;
798 case NFULNL_CFG_CMD_UNBIND:
799 if (!inst) {
800 ret = -ENODEV;
801 goto out;
802 }
803
804 if (inst->peer_pid != NETLINK_CB(skb).pid) {
805 ret = -EPERM;
806 goto out_put;
807 }
808
809 instance_destroy(inst);
810 goto out;
811 case NFULNL_CFG_CMD_PF_BIND:
812 UDEBUG("registering log handler for pf=%u\n", pf);
813 ret = nf_log_register(pf, &nfulnl_logger);
814 break;
815 case NFULNL_CFG_CMD_PF_UNBIND:
816 UDEBUG("unregistering log handler for pf=%u\n", pf);
817 /* This is a bug and a feature. We cannot unregister
818 * other handlers, like nfnetlink_inst can */
819 nf_log_unregister_pf(pf);
820 break;
821 default:
822 ret = -EINVAL;
823 break;
824 }
825
826 if (!inst)
827 goto out;
828 } else {
829 if (!inst) {
830 UDEBUG("no config command, and no instance for "
831 "group=%u pid=%u =>ENOENT\n",
832 group_num, NETLINK_CB(skb).pid);
833 ret = -ENOENT;
834 goto out;
835 }
836
837 if (inst->peer_pid != NETLINK_CB(skb).pid) {
838 UDEBUG("no config command, and wrong pid\n");
839 ret = -EPERM;
840 goto out_put;
841 }
842 }
843
844 if (nfula[NFULA_CFG_MODE]) {
845 struct nfulnl_msg_config_mode *params;
846 params = nla_data(nfula[NFULA_CFG_MODE]);
847
848 nfulnl_set_mode(inst, params->copy_mode,
849 ntohl(params->copy_range));
850 }
851
852 if (nfula[NFULA_CFG_TIMEOUT]) {
853 __be32 timeout =
854 *(__be32 *)nla_data(nfula[NFULA_CFG_TIMEOUT]);
855
856 nfulnl_set_timeout(inst, ntohl(timeout));
857 }
858
859 if (nfula[NFULA_CFG_NLBUFSIZ]) {
860 __be32 nlbufsiz =
861 *(__be32 *)nla_data(nfula[NFULA_CFG_NLBUFSIZ]);
862
863 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
864 }
865
866 if (nfula[NFULA_CFG_QTHRESH]) {
867 __be32 qthresh =
868 *(__be32 *)nla_data(nfula[NFULA_CFG_QTHRESH]);
869
870 nfulnl_set_qthresh(inst, ntohl(qthresh));
871 }
872
873 if (nfula[NFULA_CFG_FLAGS]) {
874 __be16 flags =
875 *(__be16 *)nla_data(nfula[NFULA_CFG_FLAGS]);
876 nfulnl_set_flags(inst, ntohs(flags));
877 }
878
879 out_put:
880 instance_put(inst);
881 out:
882 return ret;
883 }
884
885 static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
886 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
887 .attr_count = NFULA_MAX, },
888 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
889 .attr_count = NFULA_CFG_MAX, },
890 };
891
892 static const struct nfnetlink_subsystem nfulnl_subsys = {
893 .name = "log",
894 .subsys_id = NFNL_SUBSYS_ULOG,
895 .cb_count = NFULNL_MSG_MAX,
896 .cb = nfulnl_cb,
897 };
898
899 #ifdef CONFIG_PROC_FS
900 struct iter_state {
901 unsigned int bucket;
902 };
903
904 static struct hlist_node *get_first(struct iter_state *st)
905 {
906 if (!st)
907 return NULL;
908
909 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
910 if (!hlist_empty(&instance_table[st->bucket]))
911 return instance_table[st->bucket].first;
912 }
913 return NULL;
914 }
915
916 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
917 {
918 h = h->next;
919 while (!h) {
920 if (++st->bucket >= INSTANCE_BUCKETS)
921 return NULL;
922
923 h = instance_table[st->bucket].first;
924 }
925 return h;
926 }
927
928 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
929 {
930 struct hlist_node *head;
931 head = get_first(st);
932
933 if (head)
934 while (pos && (head = get_next(st, head)))
935 pos--;
936 return pos ? NULL : head;
937 }
938
939 static void *seq_start(struct seq_file *seq, loff_t *pos)
940 {
941 read_lock_bh(&instances_lock);
942 return get_idx(seq->private, *pos);
943 }
944
945 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
946 {
947 (*pos)++;
948 return get_next(s->private, v);
949 }
950
951 static void seq_stop(struct seq_file *s, void *v)
952 {
953 read_unlock_bh(&instances_lock);
954 }
955
956 static int seq_show(struct seq_file *s, void *v)
957 {
958 const struct nfulnl_instance *inst = v;
959
960 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
961 inst->group_num,
962 inst->peer_pid, inst->qlen,
963 inst->copy_mode, inst->copy_range,
964 inst->flushtimeout, atomic_read(&inst->use));
965 }
966
967 static const struct seq_operations nful_seq_ops = {
968 .start = seq_start,
969 .next = seq_next,
970 .stop = seq_stop,
971 .show = seq_show,
972 };
973
974 static int nful_open(struct inode *inode, struct file *file)
975 {
976 struct seq_file *seq;
977 struct iter_state *is;
978 int ret;
979
980 is = kzalloc(sizeof(*is), GFP_KERNEL);
981 if (!is)
982 return -ENOMEM;
983 ret = seq_open(file, &nful_seq_ops);
984 if (ret < 0)
985 goto out_free;
986 seq = file->private_data;
987 seq->private = is;
988 return ret;
989 out_free:
990 kfree(is);
991 return ret;
992 }
993
994 static const struct file_operations nful_file_ops = {
995 .owner = THIS_MODULE,
996 .open = nful_open,
997 .read = seq_read,
998 .llseek = seq_lseek,
999 .release = seq_release_private,
1000 };
1001
1002 #endif /* PROC_FS */
1003
1004 static int __init nfnetlink_log_init(void)
1005 {
1006 int i, status = -ENOMEM;
1007 #ifdef CONFIG_PROC_FS
1008 struct proc_dir_entry *proc_nful;
1009 #endif
1010
1011 for (i = 0; i < INSTANCE_BUCKETS; i++)
1012 INIT_HLIST_HEAD(&instance_table[i]);
1013
1014 /* it's not really all that important to have a random value, so
1015 * we can do this from the init function, even if there hasn't
1016 * been that much entropy yet */
1017 get_random_bytes(&hash_init, sizeof(hash_init));
1018
1019 netlink_register_notifier(&nfulnl_rtnl_notifier);
1020 status = nfnetlink_subsys_register(&nfulnl_subsys);
1021 if (status < 0) {
1022 printk(KERN_ERR "log: failed to create netlink socket\n");
1023 goto cleanup_netlink_notifier;
1024 }
1025
1026 #ifdef CONFIG_PROC_FS
1027 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1028 proc_net_netfilter);
1029 if (!proc_nful)
1030 goto cleanup_subsys;
1031 proc_nful->proc_fops = &nful_file_ops;
1032 #endif
1033 return status;
1034
1035 #ifdef CONFIG_PROC_FS
1036 cleanup_subsys:
1037 nfnetlink_subsys_unregister(&nfulnl_subsys);
1038 #endif
1039 cleanup_netlink_notifier:
1040 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1041 return status;
1042 }
1043
1044 static void __exit nfnetlink_log_fini(void)
1045 {
1046 nf_log_unregister(&nfulnl_logger);
1047 #ifdef CONFIG_PROC_FS
1048 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1049 #endif
1050 nfnetlink_subsys_unregister(&nfulnl_subsys);
1051 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1052 }
1053
1054 MODULE_DESCRIPTION("netfilter userspace logging");
1055 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1056 MODULE_LICENSE("GPL");
1057 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1058
1059 module_init(nfnetlink_log_init);
1060 module_exit(nfnetlink_log_fini);
Linux kernel - Deliverables
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