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Commit | Line | Data |
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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 | ||
149 | inst = kmalloc(sizeof(*inst), GFP_ATOMIC); | |
150 | if (!inst) | |
151 | goto out_unlock; | |
152 | ||
153 | memset(inst, 0, sizeof(*inst)); | |
154 | INIT_HLIST_NODE(&inst->hlist); | |
155 | inst->lock = SPIN_LOCK_UNLOCKED; | |
156 | /* needs to be two, since we _put() after creation */ | |
157 | atomic_set(&inst->use, 2); | |
158 | ||
159 | init_timer(&inst->timer); | |
160 | inst->timer.function = nfulnl_timer; | |
161 | inst->timer.data = (unsigned long)inst; | |
162 | /* don't start timer yet. (re)start it with every packet */ | |
163 | ||
164 | inst->peer_pid = pid; | |
165 | inst->group_num = group_num; | |
166 | ||
167 | inst->qthreshold = NFULNL_QTHRESH_DEFAULT; | |
168 | inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; | |
169 | inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; | |
170 | inst->copy_mode = NFULNL_COPY_PACKET; | |
171 | inst->copy_range = 0xffff; | |
172 | ||
173 | if (!try_module_get(THIS_MODULE)) | |
174 | goto out_free; | |
175 | ||
176 | hlist_add_head(&inst->hlist, | |
177 | &instance_table[instance_hashfn(group_num)]); | |
178 | ||
179 | UDEBUG("newly added node: %p, next=%p\n", &inst->hlist, | |
180 | inst->hlist.next); | |
181 | ||
182 | write_unlock_bh(&instances_lock); | |
183 | ||
184 | return inst; | |
185 | ||
186 | out_free: | |
187 | instance_put(inst); | |
188 | out_unlock: | |
189 | write_unlock_bh(&instances_lock); | |
190 | return NULL; | |
191 | } | |
192 | ||
193 | static int __nfulnl_send(struct nfulnl_instance *inst); | |
194 | ||
195 | static void | |
196 | _instance_destroy2(struct nfulnl_instance *inst, int lock) | |
197 | { | |
198 | /* first pull it out of the global list */ | |
199 | if (lock) | |
200 | write_lock_bh(&instances_lock); | |
201 | ||
202 | UDEBUG("removing instance %p (queuenum=%u) from hash\n", | |
203 | inst, inst->group_num); | |
204 | ||
205 | hlist_del(&inst->hlist); | |
206 | ||
207 | if (lock) | |
208 | write_unlock_bh(&instances_lock); | |
209 | ||
210 | /* then flush all pending packets from skb */ | |
211 | ||
212 | spin_lock_bh(&inst->lock); | |
213 | if (inst->skb) { | |
214 | if (inst->qlen) | |
215 | __nfulnl_send(inst); | |
216 | if (inst->skb) { | |
217 | kfree_skb(inst->skb); | |
218 | inst->skb = NULL; | |
219 | } | |
220 | } | |
221 | spin_unlock_bh(&inst->lock); | |
222 | ||
223 | /* and finally put the refcount */ | |
224 | instance_put(inst); | |
225 | ||
226 | module_put(THIS_MODULE); | |
227 | } | |
228 | ||
229 | static inline void | |
230 | __instance_destroy(struct nfulnl_instance *inst) | |
231 | { | |
232 | _instance_destroy2(inst, 0); | |
233 | } | |
234 | ||
235 | static inline void | |
236 | instance_destroy(struct nfulnl_instance *inst) | |
237 | { | |
238 | _instance_destroy2(inst, 1); | |
239 | } | |
240 | ||
241 | static int | |
242 | nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, | |
243 | unsigned int range) | |
244 | { | |
245 | int status = 0; | |
246 | ||
247 | spin_lock_bh(&inst->lock); | |
248 | ||
249 | switch (mode) { | |
250 | case NFULNL_COPY_NONE: | |
251 | case NFULNL_COPY_META: | |
252 | inst->copy_mode = mode; | |
253 | inst->copy_range = 0; | |
254 | break; | |
255 | ||
256 | case NFULNL_COPY_PACKET: | |
257 | inst->copy_mode = mode; | |
258 | /* we're using struct nfattr which has 16bit nfa_len */ | |
259 | if (range > 0xffff) | |
260 | inst->copy_range = 0xffff; | |
261 | else | |
262 | inst->copy_range = range; | |
263 | break; | |
264 | ||
265 | default: | |
266 | status = -EINVAL; | |
267 | break; | |
268 | } | |
269 | ||
270 | spin_unlock_bh(&inst->lock); | |
271 | ||
272 | return status; | |
273 | } | |
274 | ||
275 | static int | |
276 | nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) | |
277 | { | |
278 | int status; | |
279 | ||
280 | spin_lock_bh(&inst->lock); | |
281 | if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) | |
282 | status = -ERANGE; | |
283 | else if (nlbufsiz > 131072) | |
284 | status = -ERANGE; | |
285 | else { | |
286 | inst->nlbufsiz = nlbufsiz; | |
287 | status = 0; | |
288 | } | |
289 | spin_unlock_bh(&inst->lock); | |
290 | ||
291 | return status; | |
292 | } | |
293 | ||
294 | static int | |
295 | nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) | |
296 | { | |
297 | spin_lock_bh(&inst->lock); | |
298 | inst->flushtimeout = timeout; | |
299 | spin_unlock_bh(&inst->lock); | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | static int | |
305 | nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) | |
306 | { | |
307 | spin_lock_bh(&inst->lock); | |
308 | inst->qthreshold = qthresh; | |
309 | spin_unlock_bh(&inst->lock); | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
314 | static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size, | |
315 | unsigned int pkt_size) | |
316 | { | |
317 | struct sk_buff *skb; | |
318 | ||
319 | UDEBUG("entered (%u, %u)\n", inst_size, pkt_size); | |
320 | ||
321 | /* alloc skb which should be big enough for a whole multipart | |
322 | * message. WARNING: has to be <= 128k due to slab restrictions */ | |
323 | ||
324 | skb = alloc_skb(inst_size, GFP_ATOMIC); | |
325 | if (!skb) { | |
326 | PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n", | |
327 | inst_size); | |
328 | ||
329 | /* try to allocate only as much as we need for current | |
330 | * packet */ | |
331 | ||
332 | skb = alloc_skb(pkt_size, GFP_ATOMIC); | |
333 | if (!skb) | |
334 | PRINTR("nfnetlink_log: can't even alloc %u bytes\n", | |
335 | pkt_size); | |
336 | } | |
337 | ||
338 | return skb; | |
339 | } | |
340 | ||
341 | static int | |
342 | __nfulnl_send(struct nfulnl_instance *inst) | |
343 | { | |
344 | int status; | |
345 | ||
346 | if (timer_pending(&inst->timer)) | |
347 | del_timer(&inst->timer); | |
348 | ||
349 | if (inst->qlen > 1) | |
350 | inst->lastnlh->nlmsg_type = NLMSG_DONE; | |
351 | ||
352 | status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT); | |
353 | if (status < 0) { | |
354 | UDEBUG("netlink_unicast() failed\n"); | |
355 | /* FIXME: statistics */ | |
356 | } | |
357 | ||
358 | inst->qlen = 0; | |
359 | inst->skb = NULL; | |
360 | inst->lastnlh = NULL; | |
361 | ||
362 | return status; | |
363 | } | |
364 | ||
365 | static void nfulnl_timer(unsigned long data) | |
366 | { | |
367 | struct nfulnl_instance *inst = (struct nfulnl_instance *)data; | |
368 | ||
369 | UDEBUG("timer function called, flushing buffer\n"); | |
370 | ||
371 | spin_lock_bh(&inst->lock); | |
372 | __nfulnl_send(inst); | |
373 | instance_put(inst); | |
374 | spin_unlock_bh(&inst->lock); | |
375 | } | |
376 | ||
377 | static inline int | |
378 | __build_packet_message(struct nfulnl_instance *inst, | |
379 | const struct sk_buff *skb, | |
380 | unsigned int data_len, | |
381 | unsigned int pf, | |
382 | unsigned int hooknum, | |
383 | const struct net_device *indev, | |
384 | const struct net_device *outdev, | |
385 | const struct nf_loginfo *li, | |
386 | const char *prefix) | |
387 | { | |
388 | unsigned char *old_tail; | |
389 | struct nfulnl_msg_packet_hdr pmsg; | |
390 | struct nlmsghdr *nlh; | |
391 | struct nfgenmsg *nfmsg; | |
392 | u_int32_t tmp_uint; | |
393 | ||
394 | UDEBUG("entered\n"); | |
395 | ||
396 | old_tail = inst->skb->tail; | |
397 | nlh = NLMSG_PUT(inst->skb, 0, 0, | |
398 | NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, | |
399 | sizeof(struct nfgenmsg)); | |
400 | nfmsg = NLMSG_DATA(nlh); | |
401 | nfmsg->nfgen_family = pf; | |
402 | nfmsg->version = NFNETLINK_V0; | |
403 | nfmsg->res_id = htons(inst->group_num); | |
404 | ||
405 | pmsg.hw_protocol = htons(skb->protocol); | |
406 | pmsg.hook = hooknum; | |
407 | ||
408 | NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg); | |
409 | ||
410 | if (prefix) { | |
411 | int slen = strlen(prefix); | |
412 | if (slen > NFULNL_PREFIXLEN) | |
413 | slen = NFULNL_PREFIXLEN; | |
414 | NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix); | |
415 | } | |
416 | ||
417 | if (indev) { | |
418 | tmp_uint = htonl(indev->ifindex); | |
fbcd923c | 419 | #ifndef CONFIG_BRIDGE_NETFILTER |
0597f268 HW |
420 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint), |
421 | &tmp_uint); | |
fbcd923c HW |
422 | #else |
423 | if (pf == PF_BRIDGE) { | |
424 | /* Case 1: outdev is physical input device, we need to | |
425 | * look for bridge group (when called from | |
426 | * netfilter_bridge) */ | |
427 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV, | |
428 | sizeof(tmp_uint), &tmp_uint); | |
429 | /* this is the bridge group "brX" */ | |
430 | tmp_uint = htonl(indev->br_port->br->dev->ifindex); | |
431 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, | |
432 | sizeof(tmp_uint), &tmp_uint); | |
433 | } else { | |
434 | /* Case 2: indev is bridge group, we need to look for | |
435 | * physical device (when called from ipv4) */ | |
436 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, | |
437 | sizeof(tmp_uint), &tmp_uint); | |
438 | if (skb->nf_bridge && skb->nf_bridge->physindev) { | |
439 | tmp_uint = | |
440 | htonl(skb->nf_bridge->physindev->ifindex); | |
441 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSINDEV, | |
442 | sizeof(tmp_uint), &tmp_uint); | |
443 | } | |
444 | } | |
445 | #endif | |
0597f268 HW |
446 | } |
447 | ||
448 | if (outdev) { | |
449 | tmp_uint = htonl(outdev->ifindex); | |
fbcd923c | 450 | #ifndef CONFIG_BRIDGE_NETFILTER |
0597f268 HW |
451 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint), |
452 | &tmp_uint); | |
fbcd923c HW |
453 | #else |
454 | if (pf == PF_BRIDGE) { | |
455 | /* Case 1: outdev is physical output device, we need to | |
456 | * look for bridge group (when called from | |
457 | * netfilter_bridge) */ | |
458 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, | |
459 | sizeof(tmp_uint), &tmp_uint); | |
460 | /* this is the bridge group "brX" */ | |
461 | tmp_uint = htonl(outdev->br_port->br->dev->ifindex); | |
462 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, | |
463 | sizeof(tmp_uint), &tmp_uint); | |
464 | } else { | |
465 | /* Case 2: indev is a bridge group, we need to look | |
466 | * for physical device (when called from ipv4) */ | |
467 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, | |
468 | sizeof(tmp_uint), &tmp_uint); | |
469 | if (skb->nf_bridge) { | |
470 | tmp_uint = | |
471 | htonl(skb->nf_bridge->physoutdev->ifindex); | |
472 | NFA_PUT(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, | |
473 | sizeof(tmp_uint), &tmp_uint); | |
474 | } | |
475 | } | |
476 | #endif | |
0597f268 HW |
477 | } |
478 | ||
479 | if (skb->nfmark) { | |
480 | tmp_uint = htonl(skb->nfmark); | |
481 | NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint); | |
482 | } | |
483 | ||
484 | if (indev && skb->dev && skb->dev->hard_header_parse) { | |
485 | struct nfulnl_msg_packet_hw phw; | |
486 | ||
487 | phw.hw_addrlen = | |
488 | skb->dev->hard_header_parse((struct sk_buff *)skb, | |
489 | phw.hw_addr); | |
490 | phw.hw_addrlen = htons(phw.hw_addrlen); | |
491 | NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw); | |
492 | } | |
493 | ||
a61bbcf2 | 494 | if (skb->tstamp.off_sec) { |
0597f268 HW |
495 | struct nfulnl_msg_packet_timestamp ts; |
496 | ||
325ed823 HX |
497 | ts.sec = cpu_to_be64(skb->tstamp.off_sec); |
498 | ts.usec = cpu_to_be64(skb->tstamp.off_usec); | |
0597f268 HW |
499 | |
500 | NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts); | |
501 | } | |
502 | ||
503 | /* UID */ | |
504 | if (skb->sk) { | |
505 | read_lock_bh(&skb->sk->sk_callback_lock); | |
506 | if (skb->sk->sk_socket && skb->sk->sk_socket->file) { | |
507 | u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid); | |
508 | /* need to unlock here since NFA_PUT may goto */ | |
509 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
510 | NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid); | |
511 | } else | |
512 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
513 | } | |
514 | ||
515 | if (data_len) { | |
516 | struct nfattr *nfa; | |
517 | int size = NFA_LENGTH(data_len); | |
518 | ||
519 | if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) { | |
520 | printk(KERN_WARNING "nfnetlink_log: no tailroom!\n"); | |
521 | goto nlmsg_failure; | |
522 | } | |
523 | ||
524 | nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size)); | |
525 | nfa->nfa_type = NFULA_PAYLOAD; | |
526 | nfa->nfa_len = size; | |
527 | ||
528 | if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len)) | |
529 | BUG(); | |
530 | } | |
531 | ||
532 | nlh->nlmsg_len = inst->skb->tail - old_tail; | |
533 | return 0; | |
534 | ||
535 | nlmsg_failure: | |
536 | UDEBUG("nlmsg_failure\n"); | |
537 | nfattr_failure: | |
538 | PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); | |
539 | return -1; | |
540 | } | |
541 | ||
542 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) | |
543 | ||
544 | static struct nf_loginfo default_loginfo = { | |
545 | .type = NF_LOG_TYPE_ULOG, | |
546 | .u = { | |
547 | .ulog = { | |
548 | .copy_len = 0xffff, | |
549 | .group = 0, | |
550 | .qthreshold = 1, | |
551 | }, | |
552 | }, | |
553 | }; | |
554 | ||
555 | /* log handler for internal netfilter logging api */ | |
556 | static void | |
557 | nfulnl_log_packet(unsigned int pf, | |
558 | unsigned int hooknum, | |
559 | const struct sk_buff *skb, | |
560 | const struct net_device *in, | |
561 | const struct net_device *out, | |
562 | const struct nf_loginfo *li_user, | |
563 | const char *prefix) | |
564 | { | |
565 | unsigned int size, data_len; | |
566 | struct nfulnl_instance *inst; | |
567 | const struct nf_loginfo *li; | |
568 | unsigned int qthreshold; | |
569 | unsigned int nlbufsiz; | |
570 | ||
571 | if (li_user && li_user->type == NF_LOG_TYPE_ULOG) | |
572 | li = li_user; | |
573 | else | |
574 | li = &default_loginfo; | |
575 | ||
576 | inst = instance_lookup_get(li->u.ulog.group); | |
577 | if (!inst) | |
578 | inst = instance_lookup_get(0); | |
579 | if (!inst) { | |
580 | PRINTR("nfnetlink_log: trying to log packet, " | |
581 | "but no instance for group %u\n", li->u.ulog.group); | |
582 | return; | |
583 | } | |
584 | ||
585 | /* all macros expand to constant values at compile time */ | |
586 | /* FIXME: do we want to make the size calculation conditional based on | |
587 | * what is actually present? way more branches and checks, but more | |
588 | * memory efficient... */ | |
589 | size = NLMSG_SPACE(sizeof(struct nfgenmsg)) | |
590 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr)) | |
591 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
592 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
fbcd923c HW |
593 | #ifdef CONFIG_BRIDGE_NETFILTER |
594 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
595 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | |
596 | #endif | |
0597f268 HW |
597 | + NFA_SPACE(sizeof(u_int32_t)) /* mark */ |
598 | + NFA_SPACE(sizeof(u_int32_t)) /* uid */ | |
599 | + NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */ | |
600 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw)) | |
601 | + NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp)); | |
602 | ||
603 | UDEBUG("initial size=%u\n", size); | |
604 | ||
605 | spin_lock_bh(&inst->lock); | |
606 | ||
607 | qthreshold = inst->qthreshold; | |
608 | /* per-rule qthreshold overrides per-instance */ | |
609 | if (qthreshold > li->u.ulog.qthreshold) | |
610 | qthreshold = li->u.ulog.qthreshold; | |
611 | ||
612 | switch (inst->copy_mode) { | |
613 | case NFULNL_COPY_META: | |
614 | case NFULNL_COPY_NONE: | |
615 | data_len = 0; | |
616 | break; | |
617 | ||
618 | case NFULNL_COPY_PACKET: | |
619 | if (inst->copy_range == 0 | |
620 | || inst->copy_range > skb->len) | |
621 | data_len = skb->len; | |
622 | else | |
623 | data_len = inst->copy_range; | |
624 | ||
625 | size += NFA_SPACE(data_len); | |
626 | UDEBUG("copy_packet, therefore size now %u\n", size); | |
627 | break; | |
628 | ||
629 | default: | |
630 | spin_unlock_bh(&inst->lock); | |
631 | instance_put(inst); | |
632 | return; | |
633 | } | |
634 | ||
635 | if (size > inst->nlbufsiz) | |
636 | nlbufsiz = size; | |
637 | else | |
638 | nlbufsiz = inst->nlbufsiz; | |
639 | ||
640 | if (!inst->skb) { | |
641 | if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { | |
642 | UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", | |
643 | inst->nlbufsiz, size); | |
644 | goto alloc_failure; | |
645 | } | |
646 | } else if (inst->qlen >= qthreshold || | |
647 | size > skb_tailroom(inst->skb)) { | |
648 | /* either the queue len is too high or we don't have | |
649 | * enough room in the skb left. flush to userspace. */ | |
650 | UDEBUG("flushing old skb\n"); | |
651 | ||
652 | __nfulnl_send(inst); | |
653 | ||
654 | if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) { | |
655 | UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n", | |
656 | inst->nlbufsiz, size); | |
657 | goto alloc_failure; | |
658 | } | |
659 | } | |
660 | ||
661 | UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold); | |
662 | inst->qlen++; | |
663 | ||
664 | __build_packet_message(inst, skb, data_len, pf, | |
665 | hooknum, in, out, li, prefix); | |
666 | ||
667 | /* timer_pending always called within inst->lock, so there | |
668 | * is no chance of a race here */ | |
669 | if (!timer_pending(&inst->timer)) { | |
670 | instance_get(inst); | |
671 | inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); | |
672 | add_timer(&inst->timer); | |
673 | } | |
674 | spin_unlock_bh(&inst->lock); | |
675 | ||
676 | return; | |
677 | ||
678 | alloc_failure: | |
679 | spin_unlock_bh(&inst->lock); | |
680 | instance_put(inst); | |
681 | UDEBUG("error allocating skb\n"); | |
682 | /* FIXME: statistics */ | |
683 | } | |
684 | ||
685 | static int | |
686 | nfulnl_rcv_nl_event(struct notifier_block *this, | |
687 | unsigned long event, void *ptr) | |
688 | { | |
689 | struct netlink_notify *n = ptr; | |
690 | ||
691 | if (event == NETLINK_URELEASE && | |
692 | n->protocol == NETLINK_NETFILTER && n->pid) { | |
693 | int i; | |
694 | ||
695 | /* destroy all instances for this pid */ | |
696 | write_lock_bh(&instances_lock); | |
697 | for (i = 0; i < INSTANCE_BUCKETS; i++) { | |
698 | struct hlist_node *tmp, *t2; | |
699 | struct nfulnl_instance *inst; | |
700 | struct hlist_head *head = &instance_table[i]; | |
701 | ||
702 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { | |
703 | UDEBUG("node = %p\n", inst); | |
704 | if (n->pid == inst->peer_pid) | |
705 | __instance_destroy(inst); | |
706 | } | |
707 | } | |
708 | write_unlock_bh(&instances_lock); | |
709 | } | |
710 | return NOTIFY_DONE; | |
711 | } | |
712 | ||
713 | static struct notifier_block nfulnl_rtnl_notifier = { | |
714 | .notifier_call = nfulnl_rcv_nl_event, | |
715 | }; | |
716 | ||
717 | static int | |
718 | nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, | |
719 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) | |
720 | { | |
721 | return -ENOTSUPP; | |
722 | } | |
723 | ||
724 | static struct nf_logger nfulnl_logger = { | |
725 | .name = "nfnetlink_log", | |
726 | .logfn = &nfulnl_log_packet, | |
727 | .me = THIS_MODULE, | |
728 | }; | |
729 | ||
730 | static const int nfula_min[NFULA_MAX] = { | |
731 | [NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr), | |
732 | [NFULA_MARK-1] = sizeof(u_int32_t), | |
733 | [NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp), | |
734 | [NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t), | |
735 | [NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t), | |
736 | [NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw), | |
737 | [NFULA_PAYLOAD-1] = 0, | |
738 | [NFULA_PREFIX-1] = 0, | |
739 | [NFULA_UID-1] = sizeof(u_int32_t), | |
740 | }; | |
741 | ||
742 | static const int nfula_cfg_min[NFULA_CFG_MAX] = { | |
743 | [NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd), | |
744 | [NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode), | |
745 | [NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t), | |
746 | [NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t), | |
747 | [NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t), | |
748 | }; | |
749 | ||
750 | static int | |
751 | nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, | |
752 | struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp) | |
753 | { | |
754 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); | |
755 | u_int16_t group_num = ntohs(nfmsg->res_id); | |
756 | struct nfulnl_instance *inst; | |
757 | int ret = 0; | |
758 | ||
759 | UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); | |
760 | ||
761 | if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) { | |
762 | UDEBUG("bad attribute size\n"); | |
763 | return -EINVAL; | |
764 | } | |
765 | ||
766 | inst = instance_lookup_get(group_num); | |
767 | if (nfula[NFULA_CFG_CMD-1]) { | |
768 | u_int8_t pf = nfmsg->nfgen_family; | |
769 | struct nfulnl_msg_config_cmd *cmd; | |
770 | cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]); | |
771 | UDEBUG("found CFG_CMD for\n"); | |
772 | ||
773 | switch (cmd->command) { | |
774 | case NFULNL_CFG_CMD_BIND: | |
775 | if (inst) { | |
776 | ret = -EBUSY; | |
777 | goto out_put; | |
778 | } | |
779 | ||
780 | inst = instance_create(group_num, | |
781 | NETLINK_CB(skb).pid); | |
782 | if (!inst) { | |
783 | ret = -EINVAL; | |
784 | goto out_put; | |
785 | } | |
786 | break; | |
787 | case NFULNL_CFG_CMD_UNBIND: | |
788 | if (!inst) { | |
789 | ret = -ENODEV; | |
790 | goto out_put; | |
791 | } | |
792 | ||
793 | if (inst->peer_pid != NETLINK_CB(skb).pid) { | |
794 | ret = -EPERM; | |
795 | goto out_put; | |
796 | } | |
797 | ||
798 | instance_destroy(inst); | |
799 | break; | |
800 | case NFULNL_CFG_CMD_PF_BIND: | |
801 | UDEBUG("registering log handler for pf=%u\n", pf); | |
802 | ret = nf_log_register(pf, &nfulnl_logger); | |
803 | break; | |
804 | case NFULNL_CFG_CMD_PF_UNBIND: | |
805 | UDEBUG("unregistering log handler for pf=%u\n", pf); | |
806 | /* This is a bug and a feature. We cannot unregister | |
807 | * other handlers, like nfnetlink_inst can */ | |
808 | nf_log_unregister_pf(pf); | |
809 | break; | |
810 | default: | |
811 | ret = -EINVAL; | |
812 | break; | |
813 | } | |
814 | } else { | |
815 | if (!inst) { | |
816 | UDEBUG("no config command, and no instance for " | |
817 | "group=%u pid=%u =>ENOENT\n", | |
818 | group_num, NETLINK_CB(skb).pid); | |
819 | ret = -ENOENT; | |
820 | goto out_put; | |
821 | } | |
822 | ||
823 | if (inst->peer_pid != NETLINK_CB(skb).pid) { | |
824 | UDEBUG("no config command, and wrong pid\n"); | |
825 | ret = -EPERM; | |
826 | goto out_put; | |
827 | } | |
828 | } | |
829 | ||
830 | if (nfula[NFULA_CFG_MODE-1]) { | |
831 | struct nfulnl_msg_config_mode *params; | |
832 | params = NFA_DATA(nfula[NFULA_CFG_MODE-1]); | |
833 | ||
834 | nfulnl_set_mode(inst, params->copy_mode, | |
835 | ntohs(params->copy_range)); | |
836 | } | |
837 | ||
838 | if (nfula[NFULA_CFG_TIMEOUT-1]) { | |
839 | u_int32_t timeout = | |
840 | *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]); | |
841 | ||
842 | nfulnl_set_timeout(inst, ntohl(timeout)); | |
843 | } | |
844 | ||
845 | if (nfula[NFULA_CFG_NLBUFSIZ-1]) { | |
846 | u_int32_t nlbufsiz = | |
847 | *(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]); | |
848 | ||
849 | nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); | |
850 | } | |
851 | ||
852 | if (nfula[NFULA_CFG_QTHRESH-1]) { | |
853 | u_int32_t qthresh = | |
854 | *(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]); | |
855 | ||
856 | nfulnl_set_qthresh(inst, ntohl(qthresh)); | |
857 | } | |
858 | ||
859 | out_put: | |
860 | instance_put(inst); | |
861 | return ret; | |
862 | } | |
863 | ||
864 | static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { | |
865 | [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, | |
927ccbcc HW |
866 | .attr_count = NFULA_MAX, |
867 | .cap_required = CAP_NET_ADMIN, }, | |
0597f268 | 868 | [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, |
927ccbcc | 869 | .attr_count = NFULA_CFG_MAX, |
0597f268 HW |
870 | .cap_required = CAP_NET_ADMIN }, |
871 | }; | |
872 | ||
873 | static struct nfnetlink_subsystem nfulnl_subsys = { | |
874 | .name = "log", | |
875 | .subsys_id = NFNL_SUBSYS_ULOG, | |
876 | .cb_count = NFULNL_MSG_MAX, | |
0597f268 HW |
877 | .cb = nfulnl_cb, |
878 | }; | |
879 | ||
880 | #ifdef CONFIG_PROC_FS | |
881 | struct iter_state { | |
882 | unsigned int bucket; | |
883 | }; | |
884 | ||
885 | static struct hlist_node *get_first(struct seq_file *seq) | |
886 | { | |
887 | struct iter_state *st = seq->private; | |
888 | ||
889 | if (!st) | |
890 | return NULL; | |
891 | ||
892 | for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { | |
893 | if (!hlist_empty(&instance_table[st->bucket])) | |
894 | return instance_table[st->bucket].first; | |
895 | } | |
896 | return NULL; | |
897 | } | |
898 | ||
899 | static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) | |
900 | { | |
901 | struct iter_state *st = seq->private; | |
902 | ||
903 | h = h->next; | |
904 | while (!h) { | |
905 | if (++st->bucket >= INSTANCE_BUCKETS) | |
906 | return NULL; | |
907 | ||
908 | h = instance_table[st->bucket].first; | |
909 | } | |
910 | return h; | |
911 | } | |
912 | ||
913 | static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) | |
914 | { | |
915 | struct hlist_node *head; | |
916 | head = get_first(seq); | |
917 | ||
918 | if (head) | |
919 | while (pos && (head = get_next(seq, head))) | |
920 | pos--; | |
921 | return pos ? NULL : head; | |
922 | } | |
923 | ||
924 | static void *seq_start(struct seq_file *seq, loff_t *pos) | |
925 | { | |
926 | read_lock_bh(&instances_lock); | |
927 | return get_idx(seq, *pos); | |
928 | } | |
929 | ||
930 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) | |
931 | { | |
932 | (*pos)++; | |
933 | return get_next(s, v); | |
934 | } | |
935 | ||
936 | static void seq_stop(struct seq_file *s, void *v) | |
937 | { | |
938 | read_unlock_bh(&instances_lock); | |
939 | } | |
940 | ||
941 | static int seq_show(struct seq_file *s, void *v) | |
942 | { | |
943 | const struct nfulnl_instance *inst = v; | |
944 | ||
945 | return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", | |
946 | inst->group_num, | |
947 | inst->peer_pid, inst->qlen, | |
948 | inst->copy_mode, inst->copy_range, | |
949 | inst->flushtimeout, atomic_read(&inst->use)); | |
950 | } | |
951 | ||
952 | static struct seq_operations nful_seq_ops = { | |
953 | .start = seq_start, | |
954 | .next = seq_next, | |
955 | .stop = seq_stop, | |
956 | .show = seq_show, | |
957 | }; | |
958 | ||
959 | static int nful_open(struct inode *inode, struct file *file) | |
960 | { | |
961 | struct seq_file *seq; | |
962 | struct iter_state *is; | |
963 | int ret; | |
964 | ||
965 | is = kmalloc(sizeof(*is), GFP_KERNEL); | |
966 | if (!is) | |
967 | return -ENOMEM; | |
968 | memset(is, 0, sizeof(*is)); | |
969 | ret = seq_open(file, &nful_seq_ops); | |
970 | if (ret < 0) | |
971 | goto out_free; | |
972 | seq = file->private_data; | |
973 | seq->private = is; | |
974 | return ret; | |
975 | out_free: | |
976 | kfree(is); | |
977 | return ret; | |
978 | } | |
979 | ||
980 | static struct file_operations nful_file_ops = { | |
981 | .owner = THIS_MODULE, | |
982 | .open = nful_open, | |
983 | .read = seq_read, | |
984 | .llseek = seq_lseek, | |
985 | .release = seq_release_private, | |
986 | }; | |
987 | ||
988 | #endif /* PROC_FS */ | |
989 | ||
990 | static int | |
991 | init_or_cleanup(int init) | |
992 | { | |
993 | int i, status = -ENOMEM; | |
994 | #ifdef CONFIG_PROC_FS | |
995 | struct proc_dir_entry *proc_nful; | |
996 | #endif | |
997 | ||
998 | if (!init) | |
999 | goto cleanup; | |
1000 | ||
1001 | for (i = 0; i < INSTANCE_BUCKETS; i++) | |
1002 | INIT_HLIST_HEAD(&instance_table[i]); | |
1003 | ||
1004 | /* it's not really all that important to have a random value, so | |
1005 | * we can do this from the init function, even if there hasn't | |
1006 | * been that much entropy yet */ | |
1007 | get_random_bytes(&hash_init, sizeof(hash_init)); | |
1008 | ||
1009 | netlink_register_notifier(&nfulnl_rtnl_notifier); | |
1010 | status = nfnetlink_subsys_register(&nfulnl_subsys); | |
1011 | if (status < 0) { | |
1012 | printk(KERN_ERR "log: failed to create netlink socket\n"); | |
1013 | goto cleanup_netlink_notifier; | |
1014 | } | |
1015 | ||
1016 | #ifdef CONFIG_PROC_FS | |
1017 | proc_nful = create_proc_entry("nfnetlink_log", 0440, | |
1018 | proc_net_netfilter); | |
1019 | if (!proc_nful) | |
1020 | goto cleanup_subsys; | |
1021 | proc_nful->proc_fops = &nful_file_ops; | |
1022 | #endif | |
1023 | ||
1024 | return status; | |
1025 | ||
1026 | cleanup: | |
1027 | nf_log_unregister_logger(&nfulnl_logger); | |
1028 | #ifdef CONFIG_PROC_FS | |
1029 | remove_proc_entry("nfnetlink_log", proc_net_netfilter); | |
1030 | cleanup_subsys: | |
1031 | #endif | |
1032 | nfnetlink_subsys_unregister(&nfulnl_subsys); | |
1033 | cleanup_netlink_notifier: | |
1034 | netlink_unregister_notifier(&nfulnl_rtnl_notifier); | |
1035 | return status; | |
1036 | } | |
1037 | ||
1038 | static int __init init(void) | |
1039 | { | |
1040 | ||
1041 | return init_or_cleanup(1); | |
1042 | } | |
1043 | ||
1044 | static void __exit fini(void) | |
1045 | { | |
1046 | init_or_cleanup(0); | |
1047 | } | |
1048 | ||
1049 | MODULE_DESCRIPTION("netfilter userspace logging"); | |
1050 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
1051 | MODULE_LICENSE("GPL"); | |
f682faef | 1052 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); |
0597f268 HW |
1053 | |
1054 | module_init(init); | |
1055 | module_exit(fini); |