]>
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 | ||
fbcd923c HW |
36 | #ifdef CONFIG_BRIDGE_NETFILTER |
37 | #include "../bridge/br_private.h" | |
38 | #endif | |
39 | ||
0597f268 HW |
40 | #define NFULNL_NLBUFSIZ_DEFAULT 4096 |
41 | #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ | |
42 | #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ | |
43 | ||
44 | #define PRINTR(x, args...) do { if (net_ratelimit()) \ | |
45 | printk(x, ## args); } while (0); | |
46 | ||
47 | #if 0 | |
48 | #define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ | |
49 | __FILE__, __LINE__, __FUNCTION__, \ | |
50 | ## args) | |
51 | #else | |
52 | #define UDEBUG(x, ...) | |
53 | #endif | |
54 | ||
55 | struct nfulnl_instance { | |
56 | struct hlist_node hlist; /* global list of instances */ | |
57 | spinlock_t lock; | |
58 | atomic_t use; /* use count */ | |
59 | ||
60 | unsigned int qlen; /* number of nlmsgs in skb */ | |
61 | struct sk_buff *skb; /* pre-allocatd skb */ | |
62 | struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */ | |
63 | struct timer_list timer; | |
64 | int peer_pid; /* PID of the peer process */ | |
65 | ||
66 | /* configurable parameters */ | |
67 | unsigned int flushtimeout; /* timeout until queue flush */ | |
68 | unsigned int nlbufsiz; /* netlink buffer allocation size */ | |
69 | unsigned int qthreshold; /* threshold of the queue */ | |
70 | u_int32_t copy_range; | |
71 | u_int16_t group_num; /* number of this queue */ | |
72 | u_int8_t copy_mode; | |
73 | }; | |
74 | ||
75 | static DEFINE_RWLOCK(instances_lock); | |
76 | ||
77 | #define INSTANCE_BUCKETS 16 | |
78 | static struct hlist_head instance_table[INSTANCE_BUCKETS]; | |
79 | static unsigned int hash_init; | |
80 | ||
81 | static inline u_int8_t instance_hashfn(u_int16_t group_num) | |
82 | { | |
83 | return ((group_num & 0xff) % INSTANCE_BUCKETS); | |
84 | } | |
85 | ||
86 | static struct nfulnl_instance * | |
87 | __instance_lookup(u_int16_t group_num) | |
88 | { | |
89 | struct hlist_head *head; | |
90 | struct hlist_node *pos; | |
91 | struct nfulnl_instance *inst; | |
92 | ||
93 | UDEBUG("entering (group_num=%u)\n", group_num); | |
94 | ||
95 | head = &instance_table[instance_hashfn(group_num)]; | |
96 | hlist_for_each_entry(inst, pos, head, hlist) { | |
97 | if (inst->group_num == group_num) | |
98 | return inst; | |
99 | } | |
100 | return NULL; | |
101 | } | |
102 | ||
103 | static inline void | |
104 | instance_get(struct nfulnl_instance *inst) | |
105 | { | |
106 | atomic_inc(&inst->use); | |
107 | } | |
108 | ||
109 | static struct nfulnl_instance * | |
110 | instance_lookup_get(u_int16_t group_num) | |
111 | { | |
112 | struct nfulnl_instance *inst; | |
113 | ||
114 | read_lock_bh(&instances_lock); | |
115 | inst = __instance_lookup(group_num); | |
116 | if (inst) | |
117 | instance_get(inst); | |
118 | read_unlock_bh(&instances_lock); | |
119 | ||
120 | return inst; | |
121 | } | |
122 | ||
123 | static void | |
124 | instance_put(struct nfulnl_instance *inst) | |
125 | { | |
126 | if (inst && atomic_dec_and_test(&inst->use)) { | |
127 | UDEBUG("kfree(inst=%p)\n", inst); | |
128 | kfree(inst); | |
129 | } | |
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 | ||
139 | UDEBUG("entering (group_num=%u, pid=%d)\n", group_num, | |
140 | pid); | |
141 | ||
142 | write_lock_bh(&instances_lock); | |
143 | if (__instance_lookup(group_num)) { | |
144 | inst = NULL; | |
145 | UDEBUG("aborting, instance already exists\n"); | |
146 | goto out_unlock; | |
147 | } | |
148 | ||
10dfdc69 | 149 | inst = kzalloc(sizeof(*inst), GFP_ATOMIC); |
0597f268 HW |
150 | if (!inst) |
151 | goto out_unlock; | |
152 | ||
0597f268 HW |
153 | INIT_HLIST_NODE(&inst->hlist); |
154 | inst->lock = SPIN_LOCK_UNLOCKED; | |
155 | /* needs to be two, since we _put() after creation */ | |
156 | atomic_set(&inst->use, 2); | |
157 | ||
158 | init_timer(&inst->timer); | |
159 | inst->timer.function = nfulnl_timer; | |
160 | inst->timer.data = (unsigned long)inst; | |
161 | /* don't start timer yet. (re)start it with every packet */ | |
162 | ||
163 | inst->peer_pid = pid; | |
164 | inst->group_num = group_num; | |
165 | ||
166 | inst->qthreshold = NFULNL_QTHRESH_DEFAULT; | |
167 | inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; | |
168 | inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; | |
169 | inst->copy_mode = NFULNL_COPY_PACKET; | |
170 | inst->copy_range = 0xffff; | |
171 | ||
172 | if (!try_module_get(THIS_MODULE)) | |
173 | goto out_free; | |
174 | ||
175 | hlist_add_head(&inst->hlist, | |
176 | &instance_table[instance_hashfn(group_num)]); | |
177 | ||
178 | UDEBUG("newly added node: %p, next=%p\n", &inst->hlist, | |
179 | inst->hlist.next); | |
180 | ||
181 | write_unlock_bh(&instances_lock); | |
182 | ||
183 | return inst; | |
184 | ||
185 | out_free: | |
186 | instance_put(inst); | |
187 | out_unlock: | |
188 | write_unlock_bh(&instances_lock); | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | static int __nfulnl_send(struct nfulnl_instance *inst); | |
193 | ||
194 | static void | |
195 | _instance_destroy2(struct nfulnl_instance *inst, int lock) | |
196 | { | |
197 | /* first pull it out of the global list */ | |
198 | if (lock) | |
199 | write_lock_bh(&instances_lock); | |
200 | ||
201 | UDEBUG("removing instance %p (queuenum=%u) from hash\n", | |
202 | inst, inst->group_num); | |
203 | ||
204 | hlist_del(&inst->hlist); | |
205 | ||
206 | if (lock) | |
207 | write_unlock_bh(&instances_lock); | |
208 | ||
209 | /* then flush all pending packets from skb */ | |
210 | ||
211 | spin_lock_bh(&inst->lock); | |
212 | if (inst->skb) { | |
213 | if (inst->qlen) | |
214 | __nfulnl_send(inst); | |
215 | if (inst->skb) { | |
216 | kfree_skb(inst->skb); | |
217 | inst->skb = NULL; | |
218 | } | |
219 | } | |
220 | spin_unlock_bh(&inst->lock); | |
221 | ||
222 | /* and finally put the refcount */ | |
223 | instance_put(inst); | |
224 | ||
225 | module_put(THIS_MODULE); | |
226 | } | |
227 | ||
228 | static inline void | |
229 | __instance_destroy(struct nfulnl_instance *inst) | |
230 | { | |
231 | _instance_destroy2(inst, 0); | |
232 | } | |
233 | ||
234 | static inline void | |
235 | instance_destroy(struct nfulnl_instance *inst) | |
236 | { | |
237 | _instance_destroy2(inst, 1); | |
238 | } | |
239 | ||
240 | static int | |
241 | nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, | |
242 | unsigned int range) | |
243 | { | |
244 | int status = 0; | |
245 | ||
246 | spin_lock_bh(&inst->lock); | |
247 | ||
248 | switch (mode) { | |
249 | case NFULNL_COPY_NONE: | |
250 | case NFULNL_COPY_META: | |
251 | inst->copy_mode = mode; | |
252 | inst->copy_range = 0; | |
253 | break; | |
254 | ||
255 | case NFULNL_COPY_PACKET: | |
256 | inst->copy_mode = mode; | |
257 | /* we're using struct nfattr which has 16bit nfa_len */ | |
258 | if (range > 0xffff) | |
259 | inst->copy_range = 0xffff; | |
260 | else | |
261 | inst->copy_range = range; | |
262 | break; | |
263 | ||
264 | default: | |
265 | status = -EINVAL; | |
266 | break; | |
267 | } | |
268 | ||
269 | spin_unlock_bh(&inst->lock); | |
270 | ||
271 | return status; | |
272 | } | |
273 | ||
274 | static int | |
275 | nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) | |
276 | { | |
277 | int status; | |
278 | ||
279 | spin_lock_bh(&inst->lock); | |
280 | if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) | |
281 | status = -ERANGE; | |
282 | else if (nlbufsiz > 131072) | |
283 | status = -ERANGE; | |
284 | else { | |
285 | inst->nlbufsiz = nlbufsiz; | |
286 | status = 0; | |
287 | } | |
288 | spin_unlock_bh(&inst->lock); | |
289 | ||
290 | return status; | |
291 | } | |
292 | ||
293 | static int | |
294 | nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) | |
295 | { | |
296 | spin_lock_bh(&inst->lock); | |
297 | inst->flushtimeout = timeout; | |
298 | spin_unlock_bh(&inst->lock); | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | static int | |
304 | nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) | |
305 | { | |
306 | spin_lock_bh(&inst->lock); | |
307 | inst->qthreshold = qthresh; | |
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 | ||
318 | UDEBUG("entered (%u, %u)\n", inst_size, pkt_size); | |
319 | ||
320 | /* alloc skb which should be big enough for a whole multipart | |
321 | * message. WARNING: has to be <= 128k due to slab restrictions */ | |
322 | ||
323 | skb = alloc_skb(inst_size, GFP_ATOMIC); | |
324 | if (!skb) { | |
325 | PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n", | |
326 | inst_size); | |
327 | ||
328 | /* try to allocate only as much as we need for current | |
329 | * packet */ | |
330 | ||
331 | skb = alloc_skb(pkt_size, GFP_ATOMIC); | |
332 | if (!skb) | |
333 | PRINTR("nfnetlink_log: can't even alloc %u bytes\n", | |
334 | pkt_size); | |
335 | } | |
336 | ||
337 | return skb; | |
338 | } | |
339 | ||
340 | static int | |
341 | __nfulnl_send(struct nfulnl_instance *inst) | |
342 | { | |
343 | int status; | |
344 | ||
345 | if (timer_pending(&inst->timer)) | |
346 | del_timer(&inst->timer); | |
347 | ||
348 | if (inst->qlen > 1) | |
349 | inst->lastnlh->nlmsg_type = NLMSG_DONE; | |
350 | ||
351 | status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT); | |
352 | if (status < 0) { | |
353 | UDEBUG("netlink_unicast() failed\n"); | |
354 | /* FIXME: statistics */ | |
355 | } | |
356 | ||
357 | inst->qlen = 0; | |
358 | inst->skb = NULL; | |
359 | inst->lastnlh = NULL; | |
360 | ||
361 | return status; | |
362 | } | |
363 | ||
364 | static void nfulnl_timer(unsigned long data) | |
365 | { | |
366 | struct nfulnl_instance *inst = (struct nfulnl_instance *)data; | |
367 | ||
368 | UDEBUG("timer function called, flushing buffer\n"); | |
369 | ||
370 | spin_lock_bh(&inst->lock); | |
371 | __nfulnl_send(inst); | |
372 | instance_put(inst); | |
373 | spin_unlock_bh(&inst->lock); | |
374 | } | |
375 | ||
376 | static inline int | |
377 | __build_packet_message(struct nfulnl_instance *inst, | |
378 | const struct sk_buff *skb, | |
379 | unsigned int data_len, | |
380 | unsigned int pf, | |
381 | unsigned int hooknum, | |
382 | const struct net_device *indev, | |
383 | const struct net_device *outdev, | |
384 | const struct nf_loginfo *li, | |
385 | const char *prefix) | |
386 | { | |
387 | unsigned char *old_tail; | |
388 | struct nfulnl_msg_packet_hdr pmsg; | |
389 | struct nlmsghdr *nlh; | |
390 | struct nfgenmsg *nfmsg; | |
391 | u_int32_t tmp_uint; | |
392 | ||
393 | UDEBUG("entered\n"); | |
394 | ||
395 | old_tail = inst->skb->tail; | |
396 | nlh = NLMSG_PUT(inst->skb, 0, 0, | |
397 | NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, | |
398 | sizeof(struct nfgenmsg)); | |
399 | nfmsg = NLMSG_DATA(nlh); | |
400 | nfmsg->nfgen_family = pf; | |
401 | nfmsg->version = NFNETLINK_V0; | |
402 | nfmsg->res_id = htons(inst->group_num); | |
403 | ||
404 | pmsg.hw_protocol = htons(skb->protocol); | |
405 | pmsg.hook = hooknum; | |
406 | ||
407 | NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg); | |
408 | ||
409 | if (prefix) { | |
410 | int slen = strlen(prefix); | |
411 | if (slen > NFULNL_PREFIXLEN) | |
412 | slen = NFULNL_PREFIXLEN; | |
413 | NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix); | |
414 | } | |
415 | ||
416 | if (indev) { | |
417 | tmp_uint = htonl(indev->ifindex); | |
fbcd923c | 418 | #ifndef CONFIG_BRIDGE_NETFILTER |
0597f268 HW |
419 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint), |
420 | &tmp_uint); | |
fbcd923c HW |
421 | #else |
422 | if (pf == PF_BRIDGE) { | |
423 | /* Case 1: outdev is physical input device, we need to | |
424 | * look for bridge group (when called from | |
425 | * netfilter_bridge) */ | |
426 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV, | |
427 | sizeof(tmp_uint), &tmp_uint); | |
428 | /* this is the bridge group "brX" */ | |
429 | tmp_uint = htonl(indev->br_port->br->dev->ifindex); | |
430 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, | |
431 | sizeof(tmp_uint), &tmp_uint); | |
432 | } else { | |
433 | /* Case 2: indev is bridge group, we need to look for | |
434 | * physical device (when called from ipv4) */ | |
435 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, | |
436 | sizeof(tmp_uint), &tmp_uint); | |
437 | if (skb->nf_bridge && skb->nf_bridge->physindev) { | |
438 | tmp_uint = | |
439 | htonl(skb->nf_bridge->physindev->ifindex); | |
440 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV, | |
441 | sizeof(tmp_uint), &tmp_uint); | |
442 | } | |
443 | } | |
444 | #endif | |
0597f268 HW |
445 | } |
446 | ||
447 | if (outdev) { | |
448 | tmp_uint = htonl(outdev->ifindex); | |
fbcd923c | 449 | #ifndef CONFIG_BRIDGE_NETFILTER |
0597f268 HW |
450 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint), |
451 | &tmp_uint); | |
fbcd923c HW |
452 | #else |
453 | if (pf == PF_BRIDGE) { | |
454 | /* Case 1: outdev is physical output device, we need to | |
455 | * look for bridge group (when called from | |
456 | * netfilter_bridge) */ | |
457 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, | |
458 | sizeof(tmp_uint), &tmp_uint); | |
459 | /* this is the bridge group "brX" */ | |
460 | tmp_uint = htonl(outdev->br_port->br->dev->ifindex); | |
461 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, | |
462 | sizeof(tmp_uint), &tmp_uint); | |
463 | } else { | |
464 | /* Case 2: indev is a bridge group, we need to look | |
465 | * for physical device (when called from ipv4) */ | |
466 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, | |
467 | sizeof(tmp_uint), &tmp_uint); | |
468 | if (skb->nf_bridge) { | |
469 | tmp_uint = | |
470 | htonl(skb->nf_bridge->physoutdev->ifindex); | |
471 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, | |
472 | sizeof(tmp_uint), &tmp_uint); | |
473 | } | |
474 | } | |
475 | #endif | |
0597f268 HW |
476 | } |
477 | ||
478 | if (skb->nfmark) { | |
479 | tmp_uint = htonl(skb->nfmark); | |
480 | NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint); | |
481 | } | |
482 | ||
483 | if (indev && skb->dev && skb->dev->hard_header_parse) { | |
484 | struct nfulnl_msg_packet_hw phw; | |
485 | ||
486 | phw.hw_addrlen = | |
487 | skb->dev->hard_header_parse((struct sk_buff *)skb, | |
488 | phw.hw_addr); | |
489 | phw.hw_addrlen = htons(phw.hw_addrlen); | |
490 | NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw); | |
491 | } | |
492 | ||
a61bbcf2 | 493 | if (skb->tstamp.off_sec) { |
0597f268 HW |
494 | struct nfulnl_msg_packet_timestamp ts; |
495 | ||
325ed823 HX |
496 | ts.sec = cpu_to_be64(skb->tstamp.off_sec); |
497 | ts.usec = cpu_to_be64(skb->tstamp.off_usec); | |
0597f268 HW |
498 | |
499 | NFA_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 | u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid); | |
507 | /* need to unlock here since NFA_PUT may goto */ | |
508 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
509 | NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid); | |
510 | } else | |
511 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
512 | } | |
513 | ||
514 | if (data_len) { | |
515 | struct nfattr *nfa; | |
516 | int size = NFA_LENGTH(data_len); | |
517 | ||
518 | if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) { | |
519 | printk(KERN_WARNING "nfnetlink_log: no tailroom!\n"); | |
520 | goto nlmsg_failure; | |
521 | } | |
522 | ||
523 | nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size)); | |
524 | nfa->nfa_type = NFULA_PAYLOAD; | |
525 | nfa->nfa_len = size; | |
526 | ||
527 | if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len)) | |
528 | BUG(); | |
529 | } | |
530 | ||
531 | nlh->nlmsg_len = inst->skb->tail - old_tail; | |
532 | return 0; | |
533 | ||
534 | nlmsg_failure: | |
535 | UDEBUG("nlmsg_failure\n"); | |
536 | nfattr_failure: | |
537 | PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); | |
538 | return -1; | |
539 | } | |
540 | ||
541 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
542 | ||
543 | static struct nf_loginfo default_loginfo = { | |
544 | .type = NF_LOG_TYPE_ULOG, | |
545 | .u = { | |
546 | .ulog = { | |
547 | .copy_len = 0xffff, | |
548 | .group = 0, | |
549 | .qthreshold = 1, | |
550 | }, | |
551 | }, | |
552 | }; | |
553 | ||
554 | /* log handler for internal netfilter logging api */ | |
555 | static void | |
556 | nfulnl_log_packet(unsigned int pf, | |
557 | unsigned int hooknum, | |
558 | const struct sk_buff *skb, | |
559 | const struct net_device *in, | |
560 | const struct net_device *out, | |
561 | const struct nf_loginfo *li_user, | |
562 | const char *prefix) | |
563 | { | |
564 | unsigned int size, data_len; | |
565 | struct nfulnl_instance *inst; | |
566 | const struct nf_loginfo *li; | |
567 | unsigned int qthreshold; | |
568 | unsigned int nlbufsiz; | |
569 | ||
570 | if (li_user && li_user->type == NF_LOG_TYPE_ULOG) | |
571 | li = li_user; | |
572 | else | |
573 | li = &default_loginfo; | |
574 | ||
575 | inst = instance_lookup_get(li->u.ulog.group); | |
576 | if (!inst) | |
577 | inst = instance_lookup_get(0); | |
578 | if (!inst) { | |
579 | PRINTR("nfnetlink_log: trying to log packet, " | |
580 | "but no instance for group %u\n", li->u.ulog.group); | |
581 | return; | |
582 | } | |
583 | ||
584 | /* all macros expand to constant values at compile time */ | |
585 | /* FIXME: do we want to make the size calculation conditional based on | |
586 | * what is actually present? way more branches and checks, but more | |
587 | * memory efficient... */ | |
588 | size = NLMSG_SPACE(sizeof(struct nfgenmsg)) | |
589 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr)) | |
590 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
591 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
fbcd923c HW |
592 | #ifdef CONFIG_BRIDGE_NETFILTER |
593 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
594 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
595 | #endif | |
0597f268 HW |
596 | + NFA_SPACE(sizeof(u_int32_t)) /* mark */ |
597 | + NFA_SPACE(sizeof(u_int32_t)) /* uid */ | |
598 | + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */ | |
599 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw)) | |
600 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp)); | |
601 | ||
602 | UDEBUG("initial size=%u\n", size); | |
603 | ||
604 | spin_lock_bh(&inst->lock); | |
605 | ||
606 | qthreshold = inst->qthreshold; | |
607 | /* per-rule qthreshold overrides per-instance */ | |
608 | if (qthreshold > li->u.ulog.qthreshold) | |
609 | qthreshold = li->u.ulog.qthreshold; | |
610 | ||
611 | switch (inst->copy_mode) { | |
612 | case NFULNL_COPY_META: | |
613 | case NFULNL_COPY_NONE: | |
614 | data_len = 0; | |
615 | break; | |
616 | ||
617 | case NFULNL_COPY_PACKET: | |
618 | if (inst->copy_range == 0 | |
619 | || inst->copy_range > skb->len) | |
620 | data_len = skb->len; | |
621 | else | |
622 | data_len = inst->copy_range; | |
623 | ||
624 | size += NFA_SPACE(data_len); | |
625 | UDEBUG("copy_packet, therefore size now %u\n", size); | |
626 | break; | |
627 | ||
628 | default: | |
629 | spin_unlock_bh(&inst->lock); | |
630 | instance_put(inst); | |
631 | return; | |
632 | } | |
633 | ||
634 | if (size > inst->nlbufsiz) | |
635 | nlbufsiz = size; | |
636 | else | |
637 | nlbufsiz = inst->nlbufsiz; | |
638 | ||
639 | if (!inst->skb) { | |
640 | if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { | |
641 | UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", | |
642 | inst->nlbufsiz, size); | |
643 | goto alloc_failure; | |
644 | } | |
645 | } else if (inst->qlen >= qthreshold || | |
646 | size > skb_tailroom(inst->skb)) { | |
647 | /* either the queue len is too high or we don't have | |
648 | * enough room in the skb left. flush to userspace. */ | |
649 | UDEBUG("flushing old skb\n"); | |
650 | ||
651 | __nfulnl_send(inst); | |
652 | ||
653 | if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { | |
654 | UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", | |
655 | inst->nlbufsiz, size); | |
656 | goto alloc_failure; | |
657 | } | |
658 | } | |
659 | ||
660 | UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold); | |
661 | inst->qlen++; | |
662 | ||
663 | __build_packet_message(inst, skb, data_len, pf, | |
664 | hooknum, in, out, li, prefix); | |
665 | ||
666 | /* timer_pending always called within inst->lock, so there | |
667 | * is no chance of a race here */ | |
668 | if (!timer_pending(&inst->timer)) { | |
669 | instance_get(inst); | |
670 | inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); | |
671 | add_timer(&inst->timer); | |
672 | } | |
673 | spin_unlock_bh(&inst->lock); | |
674 | ||
675 | return; | |
676 | ||
677 | alloc_failure: | |
678 | spin_unlock_bh(&inst->lock); | |
679 | instance_put(inst); | |
680 | UDEBUG("error allocating skb\n"); | |
681 | /* FIXME: statistics */ | |
682 | } | |
683 | ||
684 | static int | |
685 | nfulnl_rcv_nl_event(struct notifier_block *this, | |
686 | unsigned long event, void *ptr) | |
687 | { | |
688 | struct netlink_notify *n = ptr; | |
689 | ||
690 | if (event == NETLINK_URELEASE && | |
691 | n->protocol == NETLINK_NETFILTER && n->pid) { | |
692 | int i; | |
693 | ||
694 | /* destroy all instances for this pid */ | |
695 | write_lock_bh(&instances_lock); | |
696 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
697 | struct hlist_node *tmp, *t2; | |
698 | struct nfulnl_instance *inst; | |
699 | struct hlist_head *head = &instance_table[i]; | |
700 | ||
701 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { | |
702 | UDEBUG("node = %p\n", inst); | |
703 | if (n->pid == inst->peer_pid) | |
704 | __instance_destroy(inst); | |
705 | } | |
706 | } | |
707 | write_unlock_bh(&instances_lock); | |
708 | } | |
709 | return NOTIFY_DONE; | |
710 | } | |
711 | ||
712 | static struct notifier_block nfulnl_rtnl_notifier = { | |
713 | .notifier_call = nfulnl_rcv_nl_event, | |
714 | }; | |
715 | ||
716 | static int | |
717 | nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, | |
718 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
719 | { | |
720 | return -ENOTSUPP; | |
721 | } | |
722 | ||
723 | static struct nf_logger nfulnl_logger = { | |
724 | .name = "nfnetlink_log", | |
725 | .logfn = &nfulnl_log_packet, | |
726 | .me = THIS_MODULE, | |
727 | }; | |
728 | ||
729 | static const int nfula_min[NFULA_MAX] = { | |
730 | [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr), | |
731 | [NFULA_MARK-1] = sizeof(u_int32_t), | |
732 | [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp), | |
733 | [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t), | |
734 | [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t), | |
735 | [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw), | |
736 | [NFULA_PAYLOAD-1] = 0, | |
737 | [NFULA_PREFIX-1] = 0, | |
738 | [NFULA_UID-1] = sizeof(u_int32_t), | |
739 | }; | |
740 | ||
741 | static const int nfula_cfg_min[NFULA_CFG_MAX] = { | |
742 | [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd), | |
743 | [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode), | |
744 | [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t), | |
745 | [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t), | |
746 | [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t), | |
747 | }; | |
748 | ||
749 | static int | |
750 | nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, | |
751 | struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp) | |
752 | { | |
753 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
754 | u_int16_t group_num = ntohs(nfmsg->res_id); | |
755 | struct nfulnl_instance *inst; | |
756 | int ret = 0; | |
757 | ||
758 | UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); | |
759 | ||
760 | if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) { | |
761 | UDEBUG("bad attribute size\n"); | |
762 | return -EINVAL; | |
763 | } | |
764 | ||
765 | inst = instance_lookup_get(group_num); | |
766 | if (nfula[NFULA_CFG_CMD-1]) { | |
767 | u_int8_t pf = nfmsg->nfgen_family; | |
768 | struct nfulnl_msg_config_cmd *cmd; | |
769 | cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]); | |
770 | UDEBUG("found CFG_CMD for\n"); | |
771 | ||
772 | switch (cmd->command) { | |
773 | case NFULNL_CFG_CMD_BIND: | |
774 | if (inst) { | |
775 | ret = -EBUSY; | |
776 | goto out_put; | |
777 | } | |
778 | ||
779 | inst = instance_create(group_num, | |
780 | NETLINK_CB(skb).pid); | |
781 | if (!inst) { | |
782 | ret = -EINVAL; | |
783 | goto out_put; | |
784 | } | |
785 | break; | |
786 | case NFULNL_CFG_CMD_UNBIND: | |
787 | if (!inst) { | |
788 | ret = -ENODEV; | |
789 | goto out_put; | |
790 | } | |
791 | ||
792 | if (inst->peer_pid != NETLINK_CB(skb).pid) { | |
793 | ret = -EPERM; | |
794 | goto out_put; | |
795 | } | |
796 | ||
797 | instance_destroy(inst); | |
798 | break; | |
799 | case NFULNL_CFG_CMD_PF_BIND: | |
800 | UDEBUG("registering log handler for pf=%u\n", pf); | |
801 | ret = nf_log_register(pf, &nfulnl_logger); | |
802 | break; | |
803 | case NFULNL_CFG_CMD_PF_UNBIND: | |
804 | UDEBUG("unregistering log handler for pf=%u\n", pf); | |
805 | /* This is a bug and a feature. We cannot unregister | |
806 | * other handlers, like nfnetlink_inst can */ | |
807 | nf_log_unregister_pf(pf); | |
808 | break; | |
809 | default: | |
810 | ret = -EINVAL; | |
811 | break; | |
812 | } | |
813 | } else { | |
814 | if (!inst) { | |
815 | UDEBUG("no config command, and no instance for " | |
816 | "group=%u pid=%u =>ENOENT\n", | |
817 | group_num, NETLINK_CB(skb).pid); | |
818 | ret = -ENOENT; | |
819 | goto out_put; | |
820 | } | |
821 | ||
822 | if (inst->peer_pid != NETLINK_CB(skb).pid) { | |
823 | UDEBUG("no config command, and wrong pid\n"); | |
824 | ret = -EPERM; | |
825 | goto out_put; | |
826 | } | |
827 | } | |
828 | ||
829 | if (nfula[NFULA_CFG_MODE-1]) { | |
830 | struct nfulnl_msg_config_mode *params; | |
831 | params = NFA_DATA(nfula[NFULA_CFG_MODE-1]); | |
832 | ||
833 | nfulnl_set_mode(inst, params->copy_mode, | |
834 | ntohs(params->copy_range)); | |
835 | } | |
836 | ||
837 | if (nfula[NFULA_CFG_TIMEOUT-1]) { | |
838 | u_int32_t timeout = | |
839 | *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]); | |
840 | ||
841 | nfulnl_set_timeout(inst, ntohl(timeout)); | |
842 | } | |
843 | ||
844 | if (nfula[NFULA_CFG_NLBUFSIZ-1]) { | |
845 | u_int32_t nlbufsiz = | |
846 | *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]); | |
847 | ||
848 | nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); | |
849 | } | |
850 | ||
851 | if (nfula[NFULA_CFG_QTHRESH-1]) { | |
852 | u_int32_t qthresh = | |
853 | *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]); | |
854 | ||
855 | nfulnl_set_qthresh(inst, ntohl(qthresh)); | |
856 | } | |
857 | ||
858 | out_put: | |
859 | instance_put(inst); | |
860 | return ret; | |
861 | } | |
862 | ||
863 | static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { | |
864 | [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, | |
37d2e7a2 | 865 | .attr_count = NFULA_MAX, }, |
0597f268 | 866 | [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, |
37d2e7a2 | 867 | .attr_count = NFULA_CFG_MAX, }, |
0597f268 HW |
868 | }; |
869 | ||
870 | static struct nfnetlink_subsystem nfulnl_subsys = { | |
871 | .name = "log", | |
872 | .subsys_id = NFNL_SUBSYS_ULOG, | |
873 | .cb_count = NFULNL_MSG_MAX, | |
0597f268 HW |
874 | .cb = nfulnl_cb, |
875 | }; | |
876 | ||
877 | #ifdef CONFIG_PROC_FS | |
878 | struct iter_state { | |
879 | unsigned int bucket; | |
880 | }; | |
881 | ||
882 | static struct hlist_node *get_first(struct seq_file *seq) | |
883 | { | |
884 | struct iter_state *st = seq->private; | |
885 | ||
886 | if (!st) | |
887 | return NULL; | |
888 | ||
889 | for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { | |
890 | if (!hlist_empty(&instance_table[st->bucket])) | |
891 | return instance_table[st->bucket].first; | |
892 | } | |
893 | return NULL; | |
894 | } | |
895 | ||
896 | static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) | |
897 | { | |
898 | struct iter_state *st = seq->private; | |
899 | ||
900 | h = h->next; | |
901 | while (!h) { | |
902 | if (++st->bucket >= INSTANCE_BUCKETS) | |
903 | return NULL; | |
904 | ||
905 | h = instance_table[st->bucket].first; | |
906 | } | |
907 | return h; | |
908 | } | |
909 | ||
910 | static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) | |
911 | { | |
912 | struct hlist_node *head; | |
913 | head = get_first(seq); | |
914 | ||
915 | if (head) | |
916 | while (pos && (head = get_next(seq, head))) | |
917 | pos--; | |
918 | return pos ? NULL : head; | |
919 | } | |
920 | ||
921 | static void *seq_start(struct seq_file *seq, loff_t *pos) | |
922 | { | |
923 | read_lock_bh(&instances_lock); | |
924 | return get_idx(seq, *pos); | |
925 | } | |
926 | ||
927 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) | |
928 | { | |
929 | (*pos)++; | |
930 | return get_next(s, v); | |
931 | } | |
932 | ||
933 | static void seq_stop(struct seq_file *s, void *v) | |
934 | { | |
935 | read_unlock_bh(&instances_lock); | |
936 | } | |
937 | ||
938 | static int seq_show(struct seq_file *s, void *v) | |
939 | { | |
940 | const struct nfulnl_instance *inst = v; | |
941 | ||
942 | return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", | |
943 | inst->group_num, | |
944 | inst->peer_pid, inst->qlen, | |
945 | inst->copy_mode, inst->copy_range, | |
946 | inst->flushtimeout, atomic_read(&inst->use)); | |
947 | } | |
948 | ||
949 | static struct seq_operations nful_seq_ops = { | |
950 | .start = seq_start, | |
951 | .next = seq_next, | |
952 | .stop = seq_stop, | |
953 | .show = seq_show, | |
954 | }; | |
955 | ||
956 | static int nful_open(struct inode *inode, struct file *file) | |
957 | { | |
958 | struct seq_file *seq; | |
959 | struct iter_state *is; | |
960 | int ret; | |
961 | ||
10dfdc69 | 962 | is = kzalloc(sizeof(*is), GFP_KERNEL); |
0597f268 HW |
963 | if (!is) |
964 | return -ENOMEM; | |
0597f268 HW |
965 | ret = seq_open(file, &nful_seq_ops); |
966 | if (ret < 0) | |
967 | goto out_free; | |
968 | seq = file->private_data; | |
969 | seq->private = is; | |
970 | return ret; | |
971 | out_free: | |
972 | kfree(is); | |
973 | return ret; | |
974 | } | |
975 | ||
976 | static struct file_operations nful_file_ops = { | |
977 | .owner = THIS_MODULE, | |
978 | .open = nful_open, | |
979 | .read = seq_read, | |
980 | .llseek = seq_lseek, | |
981 | .release = seq_release_private, | |
982 | }; | |
983 | ||
984 | #endif /* PROC_FS */ | |
985 | ||
986 | static int | |
987 | init_or_cleanup(int init) | |
988 | { | |
989 | int i, status = -ENOMEM; | |
990 | #ifdef CONFIG_PROC_FS | |
991 | struct proc_dir_entry *proc_nful; | |
992 | #endif | |
993 | ||
994 | if (!init) | |
995 | goto cleanup; | |
996 | ||
997 | for (i = 0; i < INSTANCE_BUCKETS; i++) | |
998 | INIT_HLIST_HEAD(&instance_table[i]); | |
999 | ||
1000 | /* it's not really all that important to have a random value, so | |
1001 | * we can do this from the init function, even if there hasn't | |
1002 | * been that much entropy yet */ | |
1003 | get_random_bytes(&hash_init, sizeof(hash_init)); | |
1004 | ||
1005 | netlink_register_notifier(&nfulnl_rtnl_notifier); | |
1006 | status = nfnetlink_subsys_register(&nfulnl_subsys); | |
1007 | if (status < 0) { | |
1008 | printk(KERN_ERR "log: failed to create netlink socket\n"); | |
1009 | goto cleanup_netlink_notifier; | |
1010 | } | |
1011 | ||
1012 | #ifdef CONFIG_PROC_FS | |
1013 | proc_nful = create_proc_entry("nfnetlink_log", 0440, | |
1014 | proc_net_netfilter); | |
1015 | if (!proc_nful) | |
1016 | goto cleanup_subsys; | |
1017 | proc_nful->proc_fops = &nful_file_ops; | |
1018 | #endif | |
1019 | ||
1020 | return status; | |
1021 | ||
1022 | cleanup: | |
1023 | nf_log_unregister_logger(&nfulnl_logger); | |
1024 | #ifdef CONFIG_PROC_FS | |
1025 | remove_proc_entry("nfnetlink_log", proc_net_netfilter); | |
1026 | cleanup_subsys: | |
1027 | #endif | |
1028 | nfnetlink_subsys_unregister(&nfulnl_subsys); | |
1029 | cleanup_netlink_notifier: | |
1030 | netlink_unregister_notifier(&nfulnl_rtnl_notifier); | |
1031 | return status; | |
1032 | } | |
1033 | ||
1034 | static int __init init(void) | |
1035 | { | |
1036 | ||
1037 | return init_or_cleanup(1); | |
1038 | } | |
1039 | ||
1040 | static void __exit fini(void) | |
1041 | { | |
1042 | init_or_cleanup(0); | |
1043 | } | |
1044 | ||
1045 | MODULE_DESCRIPTION("netfilter userspace logging"); | |
1046 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
1047 | MODULE_LICENSE("GPL"); | |
f682faef | 1048 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); |
0597f268 HW |
1049 | |
1050 | module_init(init); | |
1051 | module_exit(fini); |