Commit | Line | Data |
---|---|---|
0597f268 HW |
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 | */ | |
15 | #include <linux/module.h> | |
16 | #include <linux/skbuff.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/ip.h> | |
19 | #include <linux/ipv6.h> | |
20 | #include <linux/netdevice.h> | |
21 | #include <linux/netfilter.h> | |
22 | #include <linux/netlink.h> | |
23 | #include <linux/netfilter/nfnetlink.h> | |
24 | #include <linux/netfilter/nfnetlink_log.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/sysctl.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/security.h> | |
29 | #include <linux/list.h> | |
30 | #include <linux/jhash.h> | |
31 | #include <linux/random.h> | |
32 | #include <net/sock.h> | |
33 | ||
34 | #include <asm/atomic.h> | |
35 | ||
36 | #define NFULNL_NLBUFSIZ_DEFAULT 4096 | |
37 | #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ | |
38 | #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ | |
39 | ||
40 | #define PRINTR(x, args...) do { if (net_ratelimit()) \ | |
41 | printk(x, ## args); } while (0); | |
42 | ||
43 | #if 0 | |
44 | #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ | |
45 | __FILE__, __LINE__, __FUNCTION__, \ | |
46 | ## args) | |
47 | #else | |
48 | #define UDEBUG(x, ...) | |
49 | #endif | |
50 | ||
51 | struct nfulnl_instance { | |
52 | struct hlist_node hlist; /* global list of instances */ | |
53 | spinlock_t lock; | |
54 | atomic_t use; /* use count */ | |
55 | ||
56 | unsigned int qlen; /* number of nlmsgs in skb */ | |
57 | struct sk_buff *skb; /* pre-allocatd skb */ | |
58 | struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */ | |
59 | struct timer_list timer; | |
60 | int peer_pid; /* PID of the peer process */ | |
61 | ||
62 | /* configurable parameters */ | |
63 | unsigned int flushtimeout; /* timeout until queue flush */ | |
64 | unsigned int nlbufsiz; /* netlink buffer allocation size */ | |
65 | unsigned int qthreshold; /* threshold of the queue */ | |
66 | u_int32_t copy_range; | |
67 | u_int16_t group_num; /* number of this queue */ | |
68 | u_int8_t copy_mode; | |
69 | }; | |
70 | ||
71 | static DEFINE_RWLOCK(instances_lock); | |
72 | ||
73 | #define INSTANCE_BUCKETS 16 | |
74 | static struct hlist_head instance_table[INSTANCE_BUCKETS]; | |
75 | static unsigned int hash_init; | |
76 | ||
77 | static inline u_int8_t instance_hashfn(u_int16_t group_num) | |
78 | { | |
79 | return ((group_num & 0xff) % INSTANCE_BUCKETS); | |
80 | } | |
81 | ||
82 | static struct nfulnl_instance * | |
83 | __instance_lookup(u_int16_t group_num) | |
84 | { | |
85 | struct hlist_head *head; | |
86 | struct hlist_node *pos; | |
87 | struct nfulnl_instance *inst; | |
88 | ||
89 | UDEBUG("entering (group_num=%u)\n", group_num); | |
90 | ||
91 | head = &instance_table[instance_hashfn(group_num)]; | |
92 | hlist_for_each_entry(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 | read_lock_bh(&instances_lock); | |
111 | inst = __instance_lookup(group_num); | |
112 | if (inst) | |
113 | instance_get(inst); | |
114 | read_unlock_bh(&instances_lock); | |
115 | ||
116 | return inst; | |
117 | } | |
118 | ||
119 | static void | |
120 | instance_put(struct nfulnl_instance *inst) | |
121 | { | |
122 | if (inst && atomic_dec_and_test(&inst->use)) { | |
123 | UDEBUG("kfree(inst=%p)\n", inst); | |
124 | kfree(inst); | |
125 | } | |
126 | } | |
127 | ||
128 | static void nfulnl_timer(unsigned long data); | |
129 | ||
130 | static struct nfulnl_instance * | |
131 | instance_create(u_int16_t group_num, int pid) | |
132 | { | |
133 | struct nfulnl_instance *inst; | |
134 | ||
135 | UDEBUG("entering (group_num=%u, pid=%d)\n", group_num, | |
136 | pid); | |
137 | ||
138 | write_lock_bh(&instances_lock); | |
139 | if (__instance_lookup(group_num)) { | |
140 | inst = NULL; | |
141 | UDEBUG("aborting, instance already exists\n"); | |
142 | goto out_unlock; | |
143 | } | |
144 | ||
145 | inst = kmalloc(sizeof(*inst), GFP_ATOMIC); | |
146 | if (!inst) | |
147 | goto out_unlock; | |
148 | ||
149 | memset(inst, 0, sizeof(*inst)); | |
150 | INIT_HLIST_NODE(&inst->hlist); | |
151 | inst->lock = SPIN_LOCK_UNLOCKED; | |
152 | /* needs to be two, since we _put() after creation */ | |
153 | atomic_set(&inst->use, 2); | |
154 | ||
155 | init_timer(&inst->timer); | |
156 | inst->timer.function = nfulnl_timer; | |
157 | inst->timer.data = (unsigned long)inst; | |
158 | /* don't start timer yet. (re)start it with every packet */ | |
159 | ||
160 | inst->peer_pid = pid; | |
161 | inst->group_num = group_num; | |
162 | ||
163 | inst->qthreshold = NFULNL_QTHRESH_DEFAULT; | |
164 | inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; | |
165 | inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; | |
166 | inst->copy_mode = NFULNL_COPY_PACKET; | |
167 | inst->copy_range = 0xffff; | |
168 | ||
169 | if (!try_module_get(THIS_MODULE)) | |
170 | goto out_free; | |
171 | ||
172 | hlist_add_head(&inst->hlist, | |
173 | &instance_table[instance_hashfn(group_num)]); | |
174 | ||
175 | UDEBUG("newly added node: %p, next=%p\n", &inst->hlist, | |
176 | inst->hlist.next); | |
177 | ||
178 | write_unlock_bh(&instances_lock); | |
179 | ||
180 | return inst; | |
181 | ||
182 | out_free: | |
183 | instance_put(inst); | |
184 | out_unlock: | |
185 | write_unlock_bh(&instances_lock); | |
186 | return NULL; | |
187 | } | |
188 | ||
189 | static int __nfulnl_send(struct nfulnl_instance *inst); | |
190 | ||
191 | static void | |
192 | _instance_destroy2(struct nfulnl_instance *inst, int lock) | |
193 | { | |
194 | /* first pull it out of the global list */ | |
195 | if (lock) | |
196 | write_lock_bh(&instances_lock); | |
197 | ||
198 | UDEBUG("removing instance %p (queuenum=%u) from hash\n", | |
199 | inst, inst->group_num); | |
200 | ||
201 | hlist_del(&inst->hlist); | |
202 | ||
203 | if (lock) | |
204 | write_unlock_bh(&instances_lock); | |
205 | ||
206 | /* then flush all pending packets from skb */ | |
207 | ||
208 | spin_lock_bh(&inst->lock); | |
209 | if (inst->skb) { | |
210 | if (inst->qlen) | |
211 | __nfulnl_send(inst); | |
212 | if (inst->skb) { | |
213 | kfree_skb(inst->skb); | |
214 | inst->skb = NULL; | |
215 | } | |
216 | } | |
217 | spin_unlock_bh(&inst->lock); | |
218 | ||
219 | /* and finally put the refcount */ | |
220 | instance_put(inst); | |
221 | ||
222 | module_put(THIS_MODULE); | |
223 | } | |
224 | ||
225 | static inline void | |
226 | __instance_destroy(struct nfulnl_instance *inst) | |
227 | { | |
228 | _instance_destroy2(inst, 0); | |
229 | } | |
230 | ||
231 | static inline void | |
232 | instance_destroy(struct nfulnl_instance *inst) | |
233 | { | |
234 | _instance_destroy2(inst, 1); | |
235 | } | |
236 | ||
237 | static int | |
238 | nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, | |
239 | unsigned int range) | |
240 | { | |
241 | int status = 0; | |
242 | ||
243 | spin_lock_bh(&inst->lock); | |
244 | ||
245 | switch (mode) { | |
246 | case NFULNL_COPY_NONE: | |
247 | case NFULNL_COPY_META: | |
248 | inst->copy_mode = mode; | |
249 | inst->copy_range = 0; | |
250 | break; | |
251 | ||
252 | case NFULNL_COPY_PACKET: | |
253 | inst->copy_mode = mode; | |
254 | /* we're using struct nfattr which has 16bit nfa_len */ | |
255 | if (range > 0xffff) | |
256 | inst->copy_range = 0xffff; | |
257 | else | |
258 | inst->copy_range = range; | |
259 | break; | |
260 | ||
261 | default: | |
262 | status = -EINVAL; | |
263 | break; | |
264 | } | |
265 | ||
266 | spin_unlock_bh(&inst->lock); | |
267 | ||
268 | return status; | |
269 | } | |
270 | ||
271 | static int | |
272 | nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) | |
273 | { | |
274 | int status; | |
275 | ||
276 | spin_lock_bh(&inst->lock); | |
277 | if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) | |
278 | status = -ERANGE; | |
279 | else if (nlbufsiz > 131072) | |
280 | status = -ERANGE; | |
281 | else { | |
282 | inst->nlbufsiz = nlbufsiz; | |
283 | status = 0; | |
284 | } | |
285 | spin_unlock_bh(&inst->lock); | |
286 | ||
287 | return status; | |
288 | } | |
289 | ||
290 | static int | |
291 | nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) | |
292 | { | |
293 | spin_lock_bh(&inst->lock); | |
294 | inst->flushtimeout = timeout; | |
295 | spin_unlock_bh(&inst->lock); | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | static int | |
301 | nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) | |
302 | { | |
303 | spin_lock_bh(&inst->lock); | |
304 | inst->qthreshold = qthresh; | |
305 | spin_unlock_bh(&inst->lock); | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size, | |
311 | unsigned int pkt_size) | |
312 | { | |
313 | struct sk_buff *skb; | |
314 | ||
315 | UDEBUG("entered (%u, %u)\n", inst_size, pkt_size); | |
316 | ||
317 | /* alloc skb which should be big enough for a whole multipart | |
318 | * message. WARNING: has to be <= 128k due to slab restrictions */ | |
319 | ||
320 | skb = alloc_skb(inst_size, GFP_ATOMIC); | |
321 | if (!skb) { | |
322 | PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n", | |
323 | inst_size); | |
324 | ||
325 | /* try to allocate only as much as we need for current | |
326 | * packet */ | |
327 | ||
328 | skb = alloc_skb(pkt_size, GFP_ATOMIC); | |
329 | if (!skb) | |
330 | PRINTR("nfnetlink_log: can't even alloc %u bytes\n", | |
331 | pkt_size); | |
332 | } | |
333 | ||
334 | return skb; | |
335 | } | |
336 | ||
337 | static int | |
338 | __nfulnl_send(struct nfulnl_instance *inst) | |
339 | { | |
340 | int status; | |
341 | ||
342 | if (timer_pending(&inst->timer)) | |
343 | del_timer(&inst->timer); | |
344 | ||
345 | if (inst->qlen > 1) | |
346 | inst->lastnlh->nlmsg_type = NLMSG_DONE; | |
347 | ||
348 | status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT); | |
349 | if (status < 0) { | |
350 | UDEBUG("netlink_unicast() failed\n"); | |
351 | /* FIXME: statistics */ | |
352 | } | |
353 | ||
354 | inst->qlen = 0; | |
355 | inst->skb = NULL; | |
356 | inst->lastnlh = NULL; | |
357 | ||
358 | return status; | |
359 | } | |
360 | ||
361 | static void nfulnl_timer(unsigned long data) | |
362 | { | |
363 | struct nfulnl_instance *inst = (struct nfulnl_instance *)data; | |
364 | ||
365 | UDEBUG("timer function called, flushing buffer\n"); | |
366 | ||
367 | spin_lock_bh(&inst->lock); | |
368 | __nfulnl_send(inst); | |
369 | instance_put(inst); | |
370 | spin_unlock_bh(&inst->lock); | |
371 | } | |
372 | ||
373 | static inline int | |
374 | __build_packet_message(struct nfulnl_instance *inst, | |
375 | const struct sk_buff *skb, | |
376 | unsigned int data_len, | |
377 | unsigned int pf, | |
378 | unsigned int hooknum, | |
379 | const struct net_device *indev, | |
380 | const struct net_device *outdev, | |
381 | const struct nf_loginfo *li, | |
382 | const char *prefix) | |
383 | { | |
384 | unsigned char *old_tail; | |
385 | struct nfulnl_msg_packet_hdr pmsg; | |
386 | struct nlmsghdr *nlh; | |
387 | struct nfgenmsg *nfmsg; | |
388 | u_int32_t tmp_uint; | |
389 | ||
390 | UDEBUG("entered\n"); | |
391 | ||
392 | old_tail = inst->skb->tail; | |
393 | nlh = NLMSG_PUT(inst->skb, 0, 0, | |
394 | NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, | |
395 | sizeof(struct nfgenmsg)); | |
396 | nfmsg = NLMSG_DATA(nlh); | |
397 | nfmsg->nfgen_family = pf; | |
398 | nfmsg->version = NFNETLINK_V0; | |
399 | nfmsg->res_id = htons(inst->group_num); | |
400 | ||
401 | pmsg.hw_protocol = htons(skb->protocol); | |
402 | pmsg.hook = hooknum; | |
403 | ||
404 | NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg); | |
405 | ||
406 | if (prefix) { | |
407 | int slen = strlen(prefix); | |
408 | if (slen > NFULNL_PREFIXLEN) | |
409 | slen = NFULNL_PREFIXLEN; | |
410 | NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix); | |
411 | } | |
412 | ||
413 | if (indev) { | |
414 | tmp_uint = htonl(indev->ifindex); | |
415 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint), | |
416 | &tmp_uint); | |
417 | } | |
418 | ||
419 | if (outdev) { | |
420 | tmp_uint = htonl(outdev->ifindex); | |
421 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint), | |
422 | &tmp_uint); | |
423 | } | |
424 | ||
425 | if (skb->nfmark) { | |
426 | tmp_uint = htonl(skb->nfmark); | |
427 | NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint); | |
428 | } | |
429 | ||
430 | if (indev && skb->dev && skb->dev->hard_header_parse) { | |
431 | struct nfulnl_msg_packet_hw phw; | |
432 | ||
433 | phw.hw_addrlen = | |
434 | skb->dev->hard_header_parse((struct sk_buff *)skb, | |
435 | phw.hw_addr); | |
436 | phw.hw_addrlen = htons(phw.hw_addrlen); | |
437 | NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw); | |
438 | } | |
439 | ||
440 | if (skb->stamp.tv_sec) { | |
441 | struct nfulnl_msg_packet_timestamp ts; | |
442 | ||
443 | ts.sec = cpu_to_be64(skb->stamp.tv_sec); | |
444 | ts.usec = cpu_to_be64(skb->stamp.tv_usec); | |
445 | ||
446 | NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts); | |
447 | } | |
448 | ||
449 | /* UID */ | |
450 | if (skb->sk) { | |
451 | read_lock_bh(&skb->sk->sk_callback_lock); | |
452 | if (skb->sk->sk_socket && skb->sk->sk_socket->file) { | |
453 | u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid); | |
454 | /* need to unlock here since NFA_PUT may goto */ | |
455 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
456 | NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid); | |
457 | } else | |
458 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
459 | } | |
460 | ||
461 | if (data_len) { | |
462 | struct nfattr *nfa; | |
463 | int size = NFA_LENGTH(data_len); | |
464 | ||
465 | if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) { | |
466 | printk(KERN_WARNING "nfnetlink_log: no tailroom!\n"); | |
467 | goto nlmsg_failure; | |
468 | } | |
469 | ||
470 | nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size)); | |
471 | nfa->nfa_type = NFULA_PAYLOAD; | |
472 | nfa->nfa_len = size; | |
473 | ||
474 | if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len)) | |
475 | BUG(); | |
476 | } | |
477 | ||
478 | nlh->nlmsg_len = inst->skb->tail - old_tail; | |
479 | return 0; | |
480 | ||
481 | nlmsg_failure: | |
482 | UDEBUG("nlmsg_failure\n"); | |
483 | nfattr_failure: | |
484 | PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); | |
485 | return -1; | |
486 | } | |
487 | ||
488 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
489 | ||
490 | static struct nf_loginfo default_loginfo = { | |
491 | .type = NF_LOG_TYPE_ULOG, | |
492 | .u = { | |
493 | .ulog = { | |
494 | .copy_len = 0xffff, | |
495 | .group = 0, | |
496 | .qthreshold = 1, | |
497 | }, | |
498 | }, | |
499 | }; | |
500 | ||
501 | /* log handler for internal netfilter logging api */ | |
502 | static void | |
503 | nfulnl_log_packet(unsigned int pf, | |
504 | unsigned int hooknum, | |
505 | const struct sk_buff *skb, | |
506 | const struct net_device *in, | |
507 | const struct net_device *out, | |
508 | const struct nf_loginfo *li_user, | |
509 | const char *prefix) | |
510 | { | |
511 | unsigned int size, data_len; | |
512 | struct nfulnl_instance *inst; | |
513 | const struct nf_loginfo *li; | |
514 | unsigned int qthreshold; | |
515 | unsigned int nlbufsiz; | |
516 | ||
517 | if (li_user && li_user->type == NF_LOG_TYPE_ULOG) | |
518 | li = li_user; | |
519 | else | |
520 | li = &default_loginfo; | |
521 | ||
522 | inst = instance_lookup_get(li->u.ulog.group); | |
523 | if (!inst) | |
524 | inst = instance_lookup_get(0); | |
525 | if (!inst) { | |
526 | PRINTR("nfnetlink_log: trying to log packet, " | |
527 | "but no instance for group %u\n", li->u.ulog.group); | |
528 | return; | |
529 | } | |
530 | ||
531 | /* all macros expand to constant values at compile time */ | |
532 | /* FIXME: do we want to make the size calculation conditional based on | |
533 | * what is actually present? way more branches and checks, but more | |
534 | * memory efficient... */ | |
535 | size = NLMSG_SPACE(sizeof(struct nfgenmsg)) | |
536 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr)) | |
537 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
538 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
539 | + NFA_SPACE(sizeof(u_int32_t)) /* mark */ | |
540 | + NFA_SPACE(sizeof(u_int32_t)) /* uid */ | |
541 | + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */ | |
542 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw)) | |
543 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp)); | |
544 | ||
545 | UDEBUG("initial size=%u\n", size); | |
546 | ||
547 | spin_lock_bh(&inst->lock); | |
548 | ||
549 | qthreshold = inst->qthreshold; | |
550 | /* per-rule qthreshold overrides per-instance */ | |
551 | if (qthreshold > li->u.ulog.qthreshold) | |
552 | qthreshold = li->u.ulog.qthreshold; | |
553 | ||
554 | switch (inst->copy_mode) { | |
555 | case NFULNL_COPY_META: | |
556 | case NFULNL_COPY_NONE: | |
557 | data_len = 0; | |
558 | break; | |
559 | ||
560 | case NFULNL_COPY_PACKET: | |
561 | if (inst->copy_range == 0 | |
562 | || inst->copy_range > skb->len) | |
563 | data_len = skb->len; | |
564 | else | |
565 | data_len = inst->copy_range; | |
566 | ||
567 | size += NFA_SPACE(data_len); | |
568 | UDEBUG("copy_packet, therefore size now %u\n", size); | |
569 | break; | |
570 | ||
571 | default: | |
572 | spin_unlock_bh(&inst->lock); | |
573 | instance_put(inst); | |
574 | return; | |
575 | } | |
576 | ||
577 | if (size > inst->nlbufsiz) | |
578 | nlbufsiz = size; | |
579 | else | |
580 | nlbufsiz = inst->nlbufsiz; | |
581 | ||
582 | if (!inst->skb) { | |
583 | if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { | |
584 | UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", | |
585 | inst->nlbufsiz, size); | |
586 | goto alloc_failure; | |
587 | } | |
588 | } else if (inst->qlen >= qthreshold || | |
589 | size > skb_tailroom(inst->skb)) { | |
590 | /* either the queue len is too high or we don't have | |
591 | * enough room in the skb left. flush to userspace. */ | |
592 | UDEBUG("flushing old skb\n"); | |
593 | ||
594 | __nfulnl_send(inst); | |
595 | ||
596 | if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { | |
597 | UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", | |
598 | inst->nlbufsiz, size); | |
599 | goto alloc_failure; | |
600 | } | |
601 | } | |
602 | ||
603 | UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold); | |
604 | inst->qlen++; | |
605 | ||
606 | __build_packet_message(inst, skb, data_len, pf, | |
607 | hooknum, in, out, li, prefix); | |
608 | ||
609 | /* timer_pending always called within inst->lock, so there | |
610 | * is no chance of a race here */ | |
611 | if (!timer_pending(&inst->timer)) { | |
612 | instance_get(inst); | |
613 | inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); | |
614 | add_timer(&inst->timer); | |
615 | } | |
616 | spin_unlock_bh(&inst->lock); | |
617 | ||
618 | return; | |
619 | ||
620 | alloc_failure: | |
621 | spin_unlock_bh(&inst->lock); | |
622 | instance_put(inst); | |
623 | UDEBUG("error allocating skb\n"); | |
624 | /* FIXME: statistics */ | |
625 | } | |
626 | ||
627 | static int | |
628 | nfulnl_rcv_nl_event(struct notifier_block *this, | |
629 | unsigned long event, void *ptr) | |
630 | { | |
631 | struct netlink_notify *n = ptr; | |
632 | ||
633 | if (event == NETLINK_URELEASE && | |
634 | n->protocol == NETLINK_NETFILTER && n->pid) { | |
635 | int i; | |
636 | ||
637 | /* destroy all instances for this pid */ | |
638 | write_lock_bh(&instances_lock); | |
639 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
640 | struct hlist_node *tmp, *t2; | |
641 | struct nfulnl_instance *inst; | |
642 | struct hlist_head *head = &instance_table[i]; | |
643 | ||
644 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { | |
645 | UDEBUG("node = %p\n", inst); | |
646 | if (n->pid == inst->peer_pid) | |
647 | __instance_destroy(inst); | |
648 | } | |
649 | } | |
650 | write_unlock_bh(&instances_lock); | |
651 | } | |
652 | return NOTIFY_DONE; | |
653 | } | |
654 | ||
655 | static struct notifier_block nfulnl_rtnl_notifier = { | |
656 | .notifier_call = nfulnl_rcv_nl_event, | |
657 | }; | |
658 | ||
659 | static int | |
660 | nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, | |
661 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
662 | { | |
663 | return -ENOTSUPP; | |
664 | } | |
665 | ||
666 | static struct nf_logger nfulnl_logger = { | |
667 | .name = "nfnetlink_log", | |
668 | .logfn = &nfulnl_log_packet, | |
669 | .me = THIS_MODULE, | |
670 | }; | |
671 | ||
672 | static const int nfula_min[NFULA_MAX] = { | |
673 | [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr), | |
674 | [NFULA_MARK-1] = sizeof(u_int32_t), | |
675 | [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp), | |
676 | [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t), | |
677 | [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t), | |
678 | [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw), | |
679 | [NFULA_PAYLOAD-1] = 0, | |
680 | [NFULA_PREFIX-1] = 0, | |
681 | [NFULA_UID-1] = sizeof(u_int32_t), | |
682 | }; | |
683 | ||
684 | static const int nfula_cfg_min[NFULA_CFG_MAX] = { | |
685 | [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd), | |
686 | [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode), | |
687 | [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t), | |
688 | [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t), | |
689 | [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t), | |
690 | }; | |
691 | ||
692 | static int | |
693 | nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, | |
694 | struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp) | |
695 | { | |
696 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
697 | u_int16_t group_num = ntohs(nfmsg->res_id); | |
698 | struct nfulnl_instance *inst; | |
699 | int ret = 0; | |
700 | ||
701 | UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); | |
702 | ||
703 | if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) { | |
704 | UDEBUG("bad attribute size\n"); | |
705 | return -EINVAL; | |
706 | } | |
707 | ||
708 | inst = instance_lookup_get(group_num); | |
709 | if (nfula[NFULA_CFG_CMD-1]) { | |
710 | u_int8_t pf = nfmsg->nfgen_family; | |
711 | struct nfulnl_msg_config_cmd *cmd; | |
712 | cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]); | |
713 | UDEBUG("found CFG_CMD for\n"); | |
714 | ||
715 | switch (cmd->command) { | |
716 | case NFULNL_CFG_CMD_BIND: | |
717 | if (inst) { | |
718 | ret = -EBUSY; | |
719 | goto out_put; | |
720 | } | |
721 | ||
722 | inst = instance_create(group_num, | |
723 | NETLINK_CB(skb).pid); | |
724 | if (!inst) { | |
725 | ret = -EINVAL; | |
726 | goto out_put; | |
727 | } | |
728 | break; | |
729 | case NFULNL_CFG_CMD_UNBIND: | |
730 | if (!inst) { | |
731 | ret = -ENODEV; | |
732 | goto out_put; | |
733 | } | |
734 | ||
735 | if (inst->peer_pid != NETLINK_CB(skb).pid) { | |
736 | ret = -EPERM; | |
737 | goto out_put; | |
738 | } | |
739 | ||
740 | instance_destroy(inst); | |
741 | break; | |
742 | case NFULNL_CFG_CMD_PF_BIND: | |
743 | UDEBUG("registering log handler for pf=%u\n", pf); | |
744 | ret = nf_log_register(pf, &nfulnl_logger); | |
745 | break; | |
746 | case NFULNL_CFG_CMD_PF_UNBIND: | |
747 | UDEBUG("unregistering log handler for pf=%u\n", pf); | |
748 | /* This is a bug and a feature. We cannot unregister | |
749 | * other handlers, like nfnetlink_inst can */ | |
750 | nf_log_unregister_pf(pf); | |
751 | break; | |
752 | default: | |
753 | ret = -EINVAL; | |
754 | break; | |
755 | } | |
756 | } else { | |
757 | if (!inst) { | |
758 | UDEBUG("no config command, and no instance for " | |
759 | "group=%u pid=%u =>ENOENT\n", | |
760 | group_num, NETLINK_CB(skb).pid); | |
761 | ret = -ENOENT; | |
762 | goto out_put; | |
763 | } | |
764 | ||
765 | if (inst->peer_pid != NETLINK_CB(skb).pid) { | |
766 | UDEBUG("no config command, and wrong pid\n"); | |
767 | ret = -EPERM; | |
768 | goto out_put; | |
769 | } | |
770 | } | |
771 | ||
772 | if (nfula[NFULA_CFG_MODE-1]) { | |
773 | struct nfulnl_msg_config_mode *params; | |
774 | params = NFA_DATA(nfula[NFULA_CFG_MODE-1]); | |
775 | ||
776 | nfulnl_set_mode(inst, params->copy_mode, | |
777 | ntohs(params->copy_range)); | |
778 | } | |
779 | ||
780 | if (nfula[NFULA_CFG_TIMEOUT-1]) { | |
781 | u_int32_t timeout = | |
782 | *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]); | |
783 | ||
784 | nfulnl_set_timeout(inst, ntohl(timeout)); | |
785 | } | |
786 | ||
787 | if (nfula[NFULA_CFG_NLBUFSIZ-1]) { | |
788 | u_int32_t nlbufsiz = | |
789 | *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]); | |
790 | ||
791 | nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); | |
792 | } | |
793 | ||
794 | if (nfula[NFULA_CFG_QTHRESH-1]) { | |
795 | u_int32_t qthresh = | |
796 | *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]); | |
797 | ||
798 | nfulnl_set_qthresh(inst, ntohl(qthresh)); | |
799 | } | |
800 | ||
801 | out_put: | |
802 | instance_put(inst); | |
803 | return ret; | |
804 | } | |
805 | ||
806 | static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { | |
807 | [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, | |
927ccbcc HW |
808 | .attr_count = NFULA_MAX, |
809 | .cap_required = CAP_NET_ADMIN, }, | |
0597f268 | 810 | [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, |
927ccbcc | 811 | .attr_count = NFULA_CFG_MAX, |
0597f268 HW |
812 | .cap_required = CAP_NET_ADMIN }, |
813 | }; | |
814 | ||
815 | static struct nfnetlink_subsystem nfulnl_subsys = { | |
816 | .name = "log", | |
817 | .subsys_id = NFNL_SUBSYS_ULOG, | |
818 | .cb_count = NFULNL_MSG_MAX, | |
0597f268 HW |
819 | .cb = nfulnl_cb, |
820 | }; | |
821 | ||
822 | #ifdef CONFIG_PROC_FS | |
823 | struct iter_state { | |
824 | unsigned int bucket; | |
825 | }; | |
826 | ||
827 | static struct hlist_node *get_first(struct seq_file *seq) | |
828 | { | |
829 | struct iter_state *st = seq->private; | |
830 | ||
831 | if (!st) | |
832 | return NULL; | |
833 | ||
834 | for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { | |
835 | if (!hlist_empty(&instance_table[st->bucket])) | |
836 | return instance_table[st->bucket].first; | |
837 | } | |
838 | return NULL; | |
839 | } | |
840 | ||
841 | static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) | |
842 | { | |
843 | struct iter_state *st = seq->private; | |
844 | ||
845 | h = h->next; | |
846 | while (!h) { | |
847 | if (++st->bucket >= INSTANCE_BUCKETS) | |
848 | return NULL; | |
849 | ||
850 | h = instance_table[st->bucket].first; | |
851 | } | |
852 | return h; | |
853 | } | |
854 | ||
855 | static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) | |
856 | { | |
857 | struct hlist_node *head; | |
858 | head = get_first(seq); | |
859 | ||
860 | if (head) | |
861 | while (pos && (head = get_next(seq, head))) | |
862 | pos--; | |
863 | return pos ? NULL : head; | |
864 | } | |
865 | ||
866 | static void *seq_start(struct seq_file *seq, loff_t *pos) | |
867 | { | |
868 | read_lock_bh(&instances_lock); | |
869 | return get_idx(seq, *pos); | |
870 | } | |
871 | ||
872 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) | |
873 | { | |
874 | (*pos)++; | |
875 | return get_next(s, v); | |
876 | } | |
877 | ||
878 | static void seq_stop(struct seq_file *s, void *v) | |
879 | { | |
880 | read_unlock_bh(&instances_lock); | |
881 | } | |
882 | ||
883 | static int seq_show(struct seq_file *s, void *v) | |
884 | { | |
885 | const struct nfulnl_instance *inst = v; | |
886 | ||
887 | return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", | |
888 | inst->group_num, | |
889 | inst->peer_pid, inst->qlen, | |
890 | inst->copy_mode, inst->copy_range, | |
891 | inst->flushtimeout, atomic_read(&inst->use)); | |
892 | } | |
893 | ||
894 | static struct seq_operations nful_seq_ops = { | |
895 | .start = seq_start, | |
896 | .next = seq_next, | |
897 | .stop = seq_stop, | |
898 | .show = seq_show, | |
899 | }; | |
900 | ||
901 | static int nful_open(struct inode *inode, struct file *file) | |
902 | { | |
903 | struct seq_file *seq; | |
904 | struct iter_state *is; | |
905 | int ret; | |
906 | ||
907 | is = kmalloc(sizeof(*is), GFP_KERNEL); | |
908 | if (!is) | |
909 | return -ENOMEM; | |
910 | memset(is, 0, sizeof(*is)); | |
911 | ret = seq_open(file, &nful_seq_ops); | |
912 | if (ret < 0) | |
913 | goto out_free; | |
914 | seq = file->private_data; | |
915 | seq->private = is; | |
916 | return ret; | |
917 | out_free: | |
918 | kfree(is); | |
919 | return ret; | |
920 | } | |
921 | ||
922 | static struct file_operations nful_file_ops = { | |
923 | .owner = THIS_MODULE, | |
924 | .open = nful_open, | |
925 | .read = seq_read, | |
926 | .llseek = seq_lseek, | |
927 | .release = seq_release_private, | |
928 | }; | |
929 | ||
930 | #endif /* PROC_FS */ | |
931 | ||
932 | static int | |
933 | init_or_cleanup(int init) | |
934 | { | |
935 | int i, status = -ENOMEM; | |
936 | #ifdef CONFIG_PROC_FS | |
937 | struct proc_dir_entry *proc_nful; | |
938 | #endif | |
939 | ||
940 | if (!init) | |
941 | goto cleanup; | |
942 | ||
943 | for (i = 0; i < INSTANCE_BUCKETS; i++) | |
944 | INIT_HLIST_HEAD(&instance_table[i]); | |
945 | ||
946 | /* it's not really all that important to have a random value, so | |
947 | * we can do this from the init function, even if there hasn't | |
948 | * been that much entropy yet */ | |
949 | get_random_bytes(&hash_init, sizeof(hash_init)); | |
950 | ||
951 | netlink_register_notifier(&nfulnl_rtnl_notifier); | |
952 | status = nfnetlink_subsys_register(&nfulnl_subsys); | |
953 | if (status < 0) { | |
954 | printk(KERN_ERR "log: failed to create netlink socket\n"); | |
955 | goto cleanup_netlink_notifier; | |
956 | } | |
957 | ||
958 | #ifdef CONFIG_PROC_FS | |
959 | proc_nful = create_proc_entry("nfnetlink_log", 0440, | |
960 | proc_net_netfilter); | |
961 | if (!proc_nful) | |
962 | goto cleanup_subsys; | |
963 | proc_nful->proc_fops = &nful_file_ops; | |
964 | #endif | |
965 | ||
966 | return status; | |
967 | ||
968 | cleanup: | |
969 | nf_log_unregister_logger(&nfulnl_logger); | |
970 | #ifdef CONFIG_PROC_FS | |
971 | remove_proc_entry("nfnetlink_log", proc_net_netfilter); | |
972 | cleanup_subsys: | |
973 | #endif | |
974 | nfnetlink_subsys_unregister(&nfulnl_subsys); | |
975 | cleanup_netlink_notifier: | |
976 | netlink_unregister_notifier(&nfulnl_rtnl_notifier); | |
977 | return status; | |
978 | } | |
979 | ||
980 | static int __init init(void) | |
981 | { | |
982 | ||
983 | return init_or_cleanup(1); | |
984 | } | |
985 | ||
986 | static void __exit fini(void) | |
987 | { | |
988 | init_or_cleanup(0); | |
989 | } | |
990 | ||
991 | MODULE_DESCRIPTION("netfilter userspace logging"); | |
992 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
993 | MODULE_LICENSE("GPL"); | |
f682faef | 994 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); |
0597f268 HW |
995 | |
996 | module_init(init); | |
997 | module_exit(fini); |