diff options
Diffstat (limited to 'net/netfilter/nfnetlink_log.c')
-rw-r--r-- | net/netfilter/nfnetlink_log.c | 1055 |
1 files changed, 1055 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c new file mode 100644 index 00000000000..ff5601ceedc --- /dev/null +++ b/net/netfilter/nfnetlink_log.c | |||
@@ -0,0 +1,1055 @@ | |||
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 | #ifdef CONFIG_BRIDGE_NETFILTER | ||
37 | #include "../bridge/br_private.h" | ||
38 | #endif | ||
39 | |||
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); | ||
419 | #ifndef CONFIG_BRIDGE_NETFILTER | ||
420 | NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint), | ||
421 | &tmp_uint); | ||
422 | #else | ||
423 | if (pf == PF_BRIDGE) { | ||
424 | /* Case 1: outdev is physical input device, we need to | ||
425 | * look for bridge group (when called from | ||
426 | * netfilter_bridge) */ | ||
427 | 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 | ||
446 | } | ||
447 | |||
448 | if (outdev) { | ||
449 | tmp_uint = htonl(outdev->ifindex); | ||
450 | #ifndef CONFIG_BRIDGE_NETFILTER | ||
451 | NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint), | ||
452 | &tmp_uint); | ||
453 | #else | ||
454 | if (pf == PF_BRIDGE) { | ||
455 | /* Case 1: outdev is physical output device, we need to | ||
456 | * look for bridge group (when called from | ||
457 | * netfilter_bridge) */ | ||
458 | 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 | ||
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 | |||
494 | if (skb->tstamp.off_sec) { | ||
495 | struct nfulnl_msg_packet_timestamp ts; | ||
496 | |||
497 | ts.sec = cpu_to_be64(skb_tv_base.tv_sec + skb->tstamp.off_sec); | ||
498 | ts.usec = cpu_to_be64(skb_tv_base.tv_usec + skb->tstamp.off_usec); | ||
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 */ | ||
593 | #ifdef CONFIG_BRIDGE_NETFILTER | ||
594 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | ||
595 | + NFA_SPACE(sizeof(u_int32_t)) /* ifindex */ | ||
596 | #endif | ||
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, | ||
866 | .attr_count = NFULA_MAX, | ||
867 | .cap_required = CAP_NET_ADMIN, }, | ||
868 | [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, | ||
869 | .attr_count = NFULA_CFG_MAX, | ||
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, | ||
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"); | ||
1052 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); | ||
1053 | |||
1054 | module_init(init); | ||
1055 | module_exit(fini); | ||