?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[NETFILTER]: nfnetlink_log: micro-optimization: inst->skb != NULL in __nfulnl_send()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / netfilter / nfnetlink_log.c
blob34de3d84e2fc7139efacf035f2b04f92efd37ec9
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 nlmsghdr *lastnlh; /* netlink header of last msg in skb */
62 struct timer_list timer;
63 int peer_pid; /* PID of the peer process */
64
65 /* configurable parameters */
66 unsigned int flushtimeout; /* timeout until queue flush */
67 unsigned int nlbufsiz; /* netlink buffer allocation size */
68 unsigned int qthreshold; /* threshold of the queue */
69 u_int32_t copy_range;
70 u_int32_t seq; /* instance-local sequential counter */
71 u_int16_t group_num; /* number of this queue */
72 u_int16_t flags;
73 u_int8_t copy_mode;
74 };
75
76 static DEFINE_RWLOCK(instances_lock);
77 static atomic_t global_seq;
78
79 #define INSTANCE_BUCKETS 16
80 static struct hlist_head instance_table[INSTANCE_BUCKETS];
81 static unsigned int hash_init;
82
83 static inline u_int8_t instance_hashfn(u_int16_t group_num)
84 {
85 return ((group_num & 0xff) % INSTANCE_BUCKETS);
86 }
87
88 static struct nfulnl_instance *
89 __instance_lookup(u_int16_t group_num)
90 {
91 struct hlist_head *head;
92 struct hlist_node *pos;
93 struct nfulnl_instance *inst;
94
95 UDEBUG("entering (group_num=%u)\n", group_num);
96
97 head = &instance_table[instance_hashfn(group_num)];
98 hlist_for_each_entry(inst, pos, head, hlist) {
99 if (inst->group_num == group_num)
100 return inst;
101 }
102 return NULL;
103 }
104
105 static inline void
106 instance_get(struct nfulnl_instance *inst)
107 {
108 atomic_inc(&inst->use);
109 }
110
111 static struct nfulnl_instance *
112 instance_lookup_get(u_int16_t group_num)
113 {
114 struct nfulnl_instance *inst;
115
116 read_lock_bh(&instances_lock);
117 inst = __instance_lookup(group_num);
118 if (inst)
119 instance_get(inst);
120 read_unlock_bh(&instances_lock);
121
122 return inst;
123 }
124
125 static void
126 instance_put(struct nfulnl_instance *inst)
127 {
128 if (inst && atomic_dec_and_test(&inst->use)) {
129 UDEBUG("kfree(inst=%p)\n", inst);
130 kfree(inst);
131 module_put(THIS_MODULE);
132 }
133 }
134
135 static void nfulnl_timer(unsigned long data);
136
137 static struct nfulnl_instance *
138 instance_create(u_int16_t group_num, int pid)
139 {
140 struct nfulnl_instance *inst;
141
142 UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
143 pid);
144
145 write_lock_bh(&instances_lock);
146 if (__instance_lookup(group_num)) {
147 inst = NULL;
148 UDEBUG("aborting, instance already exists\n");
149 goto out_unlock;
150 }
151
152 inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
153 if (!inst)
154 goto out_unlock;
155
156 INIT_HLIST_NODE(&inst->hlist);
157 spin_lock_init(&inst->lock);
158 /* needs to be two, since we _put() after creation */
159 atomic_set(&inst->use, 2);
160
161 init_timer(&inst->timer);
162 inst->timer.function = nfulnl_timer;
163 inst->timer.data = (unsigned long)inst;
164 /* don't start timer yet. (re)start it with every packet */
165
166 inst->peer_pid = pid;
167 inst->group_num = group_num;
168
169 inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
170 inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
171 inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
172 inst->copy_mode = NFULNL_COPY_PACKET;
173 inst->copy_range = 0xffff;
174
175 if (!try_module_get(THIS_MODULE))
176 goto out_free;
177
178 hlist_add_head(&inst->hlist,
179 &instance_table[instance_hashfn(group_num)]);
180
181 UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
182 inst->hlist.next);
183
184 write_unlock_bh(&instances_lock);
185
186 return inst;
187
188 out_free:
189 instance_put(inst);
190 out_unlock:
191 write_unlock_bh(&instances_lock);
192 return NULL;
193 }
194
195 static int __nfulnl_send(struct nfulnl_instance *inst);
196
197 static void
198 _instance_destroy2(struct nfulnl_instance *inst, int lock)
199 {
200 /* first pull it out of the global list */
201 if (lock)
202 write_lock_bh(&instances_lock);
203
204 UDEBUG("removing instance %p (queuenum=%u) from hash\n",
205 inst, inst->group_num);
206
207 hlist_del(&inst->hlist);
208
209 if (lock)
210 write_unlock_bh(&instances_lock);
211
212 /* then flush all pending packets from skb */
213
214 spin_lock_bh(&inst->lock);
215 if (inst->skb) {
216 /* timer "holds" one reference (we have one more) */
217 if (del_timer(&inst->timer))
218 instance_put(inst);
219 if (inst->qlen)
220 __nfulnl_send(inst);
221 if (inst->skb) {
222 kfree_skb(inst->skb);
223 inst->skb = NULL;
224 }
225 }
226 spin_unlock_bh(&inst->lock);
227
228 /* and finally put the refcount */
229 instance_put(inst);
230 }
231
232 static inline void
233 __instance_destroy(struct nfulnl_instance *inst)
234 {
235 _instance_destroy2(inst, 0);
236 }
237
238 static inline void
239 instance_destroy(struct nfulnl_instance *inst)
240 {
241 _instance_destroy2(inst, 1);
242 }
243
244 static int
245 nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
246 unsigned int range)
247 {
248 int status = 0;
249
250 spin_lock_bh(&inst->lock);
251
252 switch (mode) {
253 case NFULNL_COPY_NONE:
254 case NFULNL_COPY_META:
255 inst->copy_mode = mode;
256 inst->copy_range = 0;
257 break;
258
259 case NFULNL_COPY_PACKET:
260 inst->copy_mode = mode;
261 /* we're using struct nfattr which has 16bit nfa_len */
262 if (range > 0xffff)
263 inst->copy_range = 0xffff;
264 else
265 inst->copy_range = range;
266 break;
267
268 default:
269 status = -EINVAL;
270 break;
271 }
272
273 spin_unlock_bh(&inst->lock);
274
275 return status;
276 }
277
278 static int
279 nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
280 {
281 int status;
282
283 spin_lock_bh(&inst->lock);
284 if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
285 status = -ERANGE;
286 else if (nlbufsiz > 131072)
287 status = -ERANGE;
288 else {
289 inst->nlbufsiz = nlbufsiz;
290 status = 0;
291 }
292 spin_unlock_bh(&inst->lock);
293
294 return status;
295 }
296
297 static int
298 nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
299 {
300 spin_lock_bh(&inst->lock);
301 inst->flushtimeout = timeout;
302 spin_unlock_bh(&inst->lock);
303
304 return 0;
305 }
306
307 static int
308 nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
309 {
310 spin_lock_bh(&inst->lock);
311 inst->qthreshold = qthresh;
312 spin_unlock_bh(&inst->lock);
313
314 return 0;
315 }
316
317 static int
318 nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
319 {
320 spin_lock_bh(&inst->lock);
321 inst->flags = flags;
322 spin_unlock_bh(&inst->lock);
323
324 return 0;
325 }
326
327 static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
328 unsigned int pkt_size)
329 {
330 struct sk_buff *skb;
331 unsigned int n;
332
333 UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
334
335 /* alloc skb which should be big enough for a whole multipart
336 * message. WARNING: has to be <= 128k due to slab restrictions */
337
338 n = max(inst_size, pkt_size);
339 skb = alloc_skb(n, GFP_ATOMIC);
340 if (!skb) {
341 PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
342 inst_size);
343
344 if (n > pkt_size) {
345 /* try to allocate only as much as we need for current
346 * packet */
347
348 skb = alloc_skb(pkt_size, GFP_ATOMIC);
349 if (!skb)
350 PRINTR("nfnetlink_log: can't even alloc %u "
351 "bytes\n", pkt_size);
352 }
353 }
354
355 return skb;
356 }
357
358 static int
359 __nfulnl_send(struct nfulnl_instance *inst)
360 {
361 int status;
362
363 if (inst->qlen > 1)
364 inst->lastnlh->nlmsg_type = NLMSG_DONE;
365
366 status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
367 if (status < 0) {
368 UDEBUG("netlink_unicast() failed\n");
369 /* FIXME: statistics */
370 }
371
372 inst->qlen = 0;
373 inst->skb = NULL;
374 inst->lastnlh = NULL;
375
376 return status;
377 }
378
379 static void nfulnl_timer(unsigned long data)
380 {
381 struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
382
383 UDEBUG("timer function called, flushing buffer\n");
384
385 spin_lock_bh(&inst->lock);
386 if (inst->skb)
387 __nfulnl_send(inst);
388 spin_unlock_bh(&inst->lock);
389 instance_put(inst);
390 }
391
392 /* This is an inline function, we don't really care about a long
393 * list of arguments */
394 static inline int
395 __build_packet_message(struct nfulnl_instance *inst,
396 const struct sk_buff *skb,
397 unsigned int data_len,
398 unsigned int pf,
399 unsigned int hooknum,
400 const struct net_device *indev,
401 const struct net_device *outdev,
402 const struct nf_loginfo *li,
403 const char *prefix, unsigned int plen)
404 {
405 struct nfulnl_msg_packet_hdr pmsg;
406 struct nlmsghdr *nlh;
407 struct nfgenmsg *nfmsg;
408 __be32 tmp_uint;
409 sk_buff_data_t old_tail = inst->skb->tail;
410
411 UDEBUG("entered\n");
412
413 nlh = NLMSG_PUT(inst->skb, 0, 0,
414 NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
415 sizeof(struct nfgenmsg));
416 nfmsg = NLMSG_DATA(nlh);
417 nfmsg->nfgen_family = pf;
418 nfmsg->version = NFNETLINK_V0;
419 nfmsg->res_id = htons(inst->group_num);
420
421 pmsg.hw_protocol = skb->protocol;
422 pmsg.hook = hooknum;
423
424 NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
425
426 if (prefix)
427 NFA_PUT(inst->skb, NFULA_PREFIX, plen, prefix);
428
429 if (indev) {
430 tmp_uint = htonl(indev->ifindex);
431 #ifndef CONFIG_BRIDGE_NETFILTER
432 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
433 &tmp_uint);
434 #else
435 if (pf == PF_BRIDGE) {
436 /* Case 1: outdev is physical input device, we need to
437 * look for bridge group (when called from
438 * netfilter_bridge) */
439 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
440 sizeof(tmp_uint), &tmp_uint);
441 /* this is the bridge group "brX" */
442 tmp_uint = htonl(indev->br_port->br->dev->ifindex);
443 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
444 sizeof(tmp_uint), &tmp_uint);
445 } else {
446 /* Case 2: indev is bridge group, we need to look for
447 * physical device (when called from ipv4) */
448 NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV,
449 sizeof(tmp_uint), &tmp_uint);
450 if (skb->nf_bridge && skb->nf_bridge->physindev) {
451 tmp_uint =
452 htonl(skb->nf_bridge->physindev->ifindex);
453 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV,
454 sizeof(tmp_uint), &tmp_uint);
455 }
456 }
457 #endif
458 }
459
460 if (outdev) {
461 tmp_uint = htonl(outdev->ifindex);
462 #ifndef CONFIG_BRIDGE_NETFILTER
463 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
464 &tmp_uint);
465 #else
466 if (pf == PF_BRIDGE) {
467 /* Case 1: outdev is physical output device, we need to
468 * look for bridge group (when called from
469 * netfilter_bridge) */
470 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
471 sizeof(tmp_uint), &tmp_uint);
472 /* this is the bridge group "brX" */
473 tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
474 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
475 sizeof(tmp_uint), &tmp_uint);
476 } else {
477 /* Case 2: indev is a bridge group, we need to look
478 * for physical device (when called from ipv4) */
479 NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV,
480 sizeof(tmp_uint), &tmp_uint);
481 if (skb->nf_bridge && skb->nf_bridge->physoutdev) {
482 tmp_uint =
483 htonl(skb->nf_bridge->physoutdev->ifindex);
484 NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
485 sizeof(tmp_uint), &tmp_uint);
486 }
487 }
488 #endif
489 }
490
491 if (skb->mark) {
492 tmp_uint = htonl(skb->mark);
493 NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
494 }
495
496 if (indev && skb->dev && skb->dev->hard_header_parse) {
497 struct nfulnl_msg_packet_hw phw;
498 int len = skb->dev->hard_header_parse((struct sk_buff *)skb,
499 phw.hw_addr);
500 phw.hw_addrlen = htons(len);
501 NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
502 }
503
504 if (skb->tstamp.tv64) {
505 struct nfulnl_msg_packet_timestamp ts;
506 struct timeval tv = ktime_to_timeval(skb->tstamp);
507 ts.sec = cpu_to_be64(tv.tv_sec);
508 ts.usec = cpu_to_be64(tv.tv_usec);
509
510 NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
511 }
512
513 /* UID */
514 if (skb->sk) {
515 read_lock_bh(&skb->sk->sk_callback_lock);
516 if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
517 __be32 uid = htonl(skb->sk->sk_socket->file->f_uid);
518 /* need to unlock here since NFA_PUT may goto */
519 read_unlock_bh(&skb->sk->sk_callback_lock);
520 NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
521 } else
522 read_unlock_bh(&skb->sk->sk_callback_lock);
523 }
524
525 /* local sequence number */
526 if (inst->flags & NFULNL_CFG_F_SEQ) {
527 tmp_uint = htonl(inst->seq++);
528 NFA_PUT(inst->skb, NFULA_SEQ, sizeof(tmp_uint), &tmp_uint);
529 }
530 /* global sequence number */
531 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) {
532 tmp_uint = htonl(atomic_inc_return(&global_seq));
533 NFA_PUT(inst->skb, NFULA_SEQ_GLOBAL, sizeof(tmp_uint), &tmp_uint);
534 }
535
536 if (data_len) {
537 struct nfattr *nfa;
538 int size = NFA_LENGTH(data_len);
539
540 if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
541 printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
542 goto nlmsg_failure;
543 }
544
545 nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
546 nfa->nfa_type = NFULA_PAYLOAD;
547 nfa->nfa_len = size;
548
549 if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
550 BUG();
551 }
552
553 nlh->nlmsg_len = inst->skb->tail - old_tail;
554 inst->lastnlh = nlh;
555 return 0;
556
557 nlmsg_failure:
558 UDEBUG("nlmsg_failure\n");
559 nfattr_failure:
560 PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
561 return -1;
562 }
563
564 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
565
566 static struct nf_loginfo default_loginfo = {
567 .type = NF_LOG_TYPE_ULOG,
568 .u = {
569 .ulog = {
570 .copy_len = 0xffff,
571 .group = 0,
572 .qthreshold = 1,
573 },
574 },
575 };
576
577 /* log handler for internal netfilter logging api */
578 static void
579 nfulnl_log_packet(unsigned int pf,
580 unsigned int hooknum,
581 const struct sk_buff *skb,
582 const struct net_device *in,
583 const struct net_device *out,
584 const struct nf_loginfo *li_user,
585 const char *prefix)
586 {
587 unsigned int size, data_len;
588 struct nfulnl_instance *inst;
589 const struct nf_loginfo *li;
590 unsigned int qthreshold;
591 unsigned int plen;
592
593 if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
594 li = li_user;
595 else
596 li = &default_loginfo;
597
598 inst = instance_lookup_get(li->u.ulog.group);
599 if (!inst)
600 inst = instance_lookup_get(0);
601 if (!inst) {
602 PRINTR("nfnetlink_log: trying to log packet, "
603 "but no instance for group %u\n", li->u.ulog.group);
604 return;
605 }
606
607 plen = 0;
608 if (prefix)
609 plen = strlen(prefix) + 1;
610
611 /* all macros expand to constant values at compile time */
612 /* FIXME: do we want to make the size calculation conditional based on
613 * what is actually present? way more branches and checks, but more
614 * memory efficient... */
615 size = NLMSG_SPACE(sizeof(struct nfgenmsg))
616 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
617 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
618 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
619 #ifdef CONFIG_BRIDGE_NETFILTER
620 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
621 + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
622 #endif
623 + NFA_SPACE(sizeof(u_int32_t)) /* mark */
624 + NFA_SPACE(sizeof(u_int32_t)) /* uid */
625 + NFA_SPACE(plen) /* prefix */
626 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
627 + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
628
629 UDEBUG("initial size=%u\n", size);
630
631 spin_lock_bh(&inst->lock);
632
633 if (inst->flags & NFULNL_CFG_F_SEQ)
634 size += NFA_SPACE(sizeof(u_int32_t));
635 if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
636 size += NFA_SPACE(sizeof(u_int32_t));
637
638 qthreshold = inst->qthreshold;
639 /* per-rule qthreshold overrides per-instance */
640 if (qthreshold > li->u.ulog.qthreshold)
641 qthreshold = li->u.ulog.qthreshold;
642
643 switch (inst->copy_mode) {
644 case NFULNL_COPY_META:
645 case NFULNL_COPY_NONE:
646 data_len = 0;
647 break;
648
649 case NFULNL_COPY_PACKET:
650 if (inst->copy_range == 0
651 || inst->copy_range > skb->len)
652 data_len = skb->len;
653 else
654 data_len = inst->copy_range;
655
656 size += NFA_SPACE(data_len);
657 UDEBUG("copy_packet, therefore size now %u\n", size);
658 break;
659
660 default:
661 goto unlock_and_release;
662 }
663
664 if (inst->qlen >= qthreshold ||
665 (inst->skb && size > skb_tailroom(inst->skb))) {
666 /* either the queue len is too high or we don't have
667 * enough room in the skb left. flush to userspace. */
668 UDEBUG("flushing old skb\n");
669
670 /* timer "holds" one reference (we have another one) */
671 if (del_timer(&inst->timer))
672 instance_put(inst);
673 __nfulnl_send(inst);
674 }
675
676 if (!inst->skb) {
677 inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size);
678 if (!inst->skb)
679 goto alloc_failure;
680 }
681
682 UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
683 inst->qlen++;
684
685 __build_packet_message(inst, skb, data_len, pf,
686 hooknum, in, out, li, prefix, plen);
687
688 /* timer_pending always called within inst->lock, so there
689 * is no chance of a race here */
690 if (!timer_pending(&inst->timer)) {
691 instance_get(inst);
692 inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
693 add_timer(&inst->timer);
694 }
695
696 unlock_and_release:
697 spin_unlock_bh(&inst->lock);
698 instance_put(inst);
699 return;
700
701 alloc_failure:
702 UDEBUG("error allocating skb\n");
703 /* FIXME: statistics */
704 goto unlock_and_release;
705 }
706
707 static int
708 nfulnl_rcv_nl_event(struct notifier_block *this,
709 unsigned long event, void *ptr)
710 {
711 struct netlink_notify *n = ptr;
712
713 if (event == NETLINK_URELEASE &&
714 n->protocol == NETLINK_NETFILTER && n->pid) {
715 int i;
716
717 /* destroy all instances for this pid */
718 write_lock_bh(&instances_lock);
719 for (i = 0; i < INSTANCE_BUCKETS; i++) {
720 struct hlist_node *tmp, *t2;
721 struct nfulnl_instance *inst;
722 struct hlist_head *head = &instance_table[i];
723
724 hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
725 UDEBUG("node = %p\n", inst);
726 if (n->pid == inst->peer_pid)
727 __instance_destroy(inst);
728 }
729 }
730 write_unlock_bh(&instances_lock);
731 }
732 return NOTIFY_DONE;
733 }
734
735 static struct notifier_block nfulnl_rtnl_notifier = {
736 .notifier_call = nfulnl_rcv_nl_event,
737 };
738
739 static int
740 nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
741 struct nlmsghdr *nlh, struct nfattr *nfqa[])
742 {
743 return -ENOTSUPP;
744 }
745
746 static struct nf_logger nfulnl_logger = {
747 .name = "nfnetlink_log",
748 .logfn = &nfulnl_log_packet,
749 .me = THIS_MODULE,
750 };
751
752 static const int nfula_min[NFULA_MAX] = {
753 [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
754 [NFULA_MARK-1] = sizeof(u_int32_t),
755 [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
756 [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
757 [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
758 [NFULA_IFINDEX_PHYSINDEV-1] = sizeof(u_int32_t),
759 [NFULA_IFINDEX_PHYSOUTDEV-1] = sizeof(u_int32_t),
760 [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
761 [NFULA_PAYLOAD-1] = 0,
762 [NFULA_PREFIX-1] = 0,
763 [NFULA_UID-1] = sizeof(u_int32_t),
764 [NFULA_SEQ-1] = sizeof(u_int32_t),
765 [NFULA_SEQ_GLOBAL-1] = sizeof(u_int32_t),
766 };
767
768 static const int nfula_cfg_min[NFULA_CFG_MAX] = {
769 [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
770 [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
771 [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
772 [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
773 [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
774 [NFULA_CFG_FLAGS-1] = sizeof(u_int16_t),
775 };
776
777 static int
778 nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
779 struct nlmsghdr *nlh, struct nfattr *nfula[])
780 {
781 struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
782 u_int16_t group_num = ntohs(nfmsg->res_id);
783 struct nfulnl_instance *inst;
784 int ret = 0;
785
786 UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
787
788 if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
789 UDEBUG("bad attribute size\n");
790 return -EINVAL;
791 }
792
793 inst = instance_lookup_get(group_num);
794 if (nfula[NFULA_CFG_CMD-1]) {
795 u_int8_t pf = nfmsg->nfgen_family;
796 struct nfulnl_msg_config_cmd *cmd;
797 cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
798 UDEBUG("found CFG_CMD for\n");
799
800 switch (cmd->command) {
801 case NFULNL_CFG_CMD_BIND:
802 if (inst) {
803 ret = -EBUSY;
804 goto out_put;
805 }
806
807 inst = instance_create(group_num,
808 NETLINK_CB(skb).pid);
809 if (!inst) {
810 ret = -EINVAL;
811 goto out;
812 }
813 break;
814 case NFULNL_CFG_CMD_UNBIND:
815 if (!inst) {
816 ret = -ENODEV;
817 goto out;
818 }
819
820 if (inst->peer_pid != NETLINK_CB(skb).pid) {
821 ret = -EPERM;
822 goto out_put;
823 }
824
825 instance_destroy(inst);
826 goto out;
827 case NFULNL_CFG_CMD_PF_BIND:
828 UDEBUG("registering log handler for pf=%u\n", pf);
829 ret = nf_log_register(pf, &nfulnl_logger);
830 break;
831 case NFULNL_CFG_CMD_PF_UNBIND:
832 UDEBUG("unregistering log handler for pf=%u\n", pf);
833 /* This is a bug and a feature. We cannot unregister
834 * other handlers, like nfnetlink_inst can */
835 nf_log_unregister_pf(pf);
836 break;
837 default:
838 ret = -EINVAL;
839 break;
840 }
841
842 if (!inst)
843 goto out;
844 } else {
845 if (!inst) {
846 UDEBUG("no config command, and no instance for "
847 "group=%u pid=%u =>ENOENT\n",
848 group_num, NETLINK_CB(skb).pid);
849 ret = -ENOENT;
850 goto out;
851 }
852
853 if (inst->peer_pid != NETLINK_CB(skb).pid) {
854 UDEBUG("no config command, and wrong pid\n");
855 ret = -EPERM;
856 goto out_put;
857 }
858 }
859
860 if (nfula[NFULA_CFG_MODE-1]) {
861 struct nfulnl_msg_config_mode *params;
862 params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
863
864 nfulnl_set_mode(inst, params->copy_mode,
865 ntohl(params->copy_range));
866 }
867
868 if (nfula[NFULA_CFG_TIMEOUT-1]) {
869 __be32 timeout =
870 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
871
872 nfulnl_set_timeout(inst, ntohl(timeout));
873 }
874
875 if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
876 __be32 nlbufsiz =
877 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
878
879 nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
880 }
881
882 if (nfula[NFULA_CFG_QTHRESH-1]) {
883 __be32 qthresh =
884 *(__be32 *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
885
886 nfulnl_set_qthresh(inst, ntohl(qthresh));
887 }
888
889 if (nfula[NFULA_CFG_FLAGS-1]) {
890 __be16 flags =
891 *(__be16 *)NFA_DATA(nfula[NFULA_CFG_FLAGS-1]);
892 nfulnl_set_flags(inst, ntohs(flags));
893 }
894
895 out_put:
896 instance_put(inst);
897 out:
898 return ret;
899 }
900
901 static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
902 [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
903 .attr_count = NFULA_MAX, },
904 [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
905 .attr_count = NFULA_CFG_MAX, },
906 };
907
908 static struct nfnetlink_subsystem nfulnl_subsys = {
909 .name = "log",
910 .subsys_id = NFNL_SUBSYS_ULOG,
911 .cb_count = NFULNL_MSG_MAX,
912 .cb = nfulnl_cb,
913 };
914
915 #ifdef CONFIG_PROC_FS
916 struct iter_state {
917 unsigned int bucket;
918 };
919
920 static struct hlist_node *get_first(struct iter_state *st)
921 {
922 if (!st)
923 return NULL;
924
925 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
926 if (!hlist_empty(&instance_table[st->bucket]))
927 return instance_table[st->bucket].first;
928 }
929 return NULL;
930 }
931
932 static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
933 {
934 h = h->next;
935 while (!h) {
936 if (++st->bucket >= INSTANCE_BUCKETS)
937 return NULL;
938
939 h = instance_table[st->bucket].first;
940 }
941 return h;
942 }
943
944 static struct hlist_node *get_idx(struct iter_state *st, loff_t pos)
945 {
946 struct hlist_node *head;
947 head = get_first(st);
948
949 if (head)
950 while (pos && (head = get_next(st, head)))
951 pos--;
952 return pos ? NULL : head;
953 }
954
955 static void *seq_start(struct seq_file *seq, loff_t *pos)
956 {
957 read_lock_bh(&instances_lock);
958 return get_idx(seq->private, *pos);
959 }
960
961 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
962 {
963 (*pos)++;
964 return get_next(s->private, v);
965 }
966
967 static void seq_stop(struct seq_file *s, void *v)
968 {
969 read_unlock_bh(&instances_lock);
970 }
971
972 static int seq_show(struct seq_file *s, void *v)
973 {
974 const struct nfulnl_instance *inst = v;
975
976 return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
977 inst->group_num,
978 inst->peer_pid, inst->qlen,
979 inst->copy_mode, inst->copy_range,
980 inst->flushtimeout, atomic_read(&inst->use));
981 }
982
983 static struct seq_operations nful_seq_ops = {
984 .start = seq_start,
985 .next = seq_next,
986 .stop = seq_stop,
987 .show = seq_show,
988 };
989
990 static int nful_open(struct inode *inode, struct file *file)
991 {
992 struct seq_file *seq;
993 struct iter_state *is;
994 int ret;
995
996 is = kzalloc(sizeof(*is), GFP_KERNEL);
997 if (!is)
998 return -ENOMEM;
999 ret = seq_open(file, &nful_seq_ops);
1000 if (ret < 0)
1001 goto out_free;
1002 seq = file->private_data;
1003 seq->private = is;
1004 return ret;
1005 out_free:
1006 kfree(is);
1007 return ret;
1008 }
1009
1010 static const struct file_operations nful_file_ops = {
1011 .owner = THIS_MODULE,
1012 .open = nful_open,
1013 .read = seq_read,
1014 .llseek = seq_lseek,
1015 .release = seq_release_private,
1016 };
1017
1018 #endif /* PROC_FS */
1019
1020 static int __init nfnetlink_log_init(void)
1021 {
1022 int i, status = -ENOMEM;
1023 #ifdef CONFIG_PROC_FS
1024 struct proc_dir_entry *proc_nful;
1025 #endif
1026
1027 for (i = 0; i < INSTANCE_BUCKETS; i++)
1028 INIT_HLIST_HEAD(&instance_table[i]);
1029
1030 /* it's not really all that important to have a random value, so
1031 * we can do this from the init function, even if there hasn't
1032 * been that much entropy yet */
1033 get_random_bytes(&hash_init, sizeof(hash_init));
1034
1035 netlink_register_notifier(&nfulnl_rtnl_notifier);
1036 status = nfnetlink_subsys_register(&nfulnl_subsys);
1037 if (status < 0) {
1038 printk(KERN_ERR "log: failed to create netlink socket\n");
1039 goto cleanup_netlink_notifier;
1040 }
1041
1042 #ifdef CONFIG_PROC_FS
1043 proc_nful = create_proc_entry("nfnetlink_log", 0440,
1044 proc_net_netfilter);
1045 if (!proc_nful)
1046 goto cleanup_subsys;
1047 proc_nful->proc_fops = &nful_file_ops;
1048 #endif
1049 return status;
1050
1051 #ifdef CONFIG_PROC_FS
1052 cleanup_subsys:
1053 nfnetlink_subsys_unregister(&nfulnl_subsys);
1054 #endif
1055 cleanup_netlink_notifier:
1056 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1057 return status;
1058 }
1059
1060 static void __exit nfnetlink_log_fini(void)
1061 {
1062 nf_log_unregister(&nfulnl_logger);
1063 #ifdef CONFIG_PROC_FS
1064 remove_proc_entry("nfnetlink_log", proc_net_netfilter);
1065 #endif
1066 nfnetlink_subsys_unregister(&nfulnl_subsys);
1067 netlink_unregister_notifier(&nfulnl_rtnl_notifier);
1068 }
1069
1070 MODULE_DESCRIPTION("netfilter userspace logging");
1071 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1072 MODULE_LICENSE("GPL");
1073 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
1074
1075 module_init(nfnetlink_log_init);
1076 module_exit(nfnetlink_log_fini);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree