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1 | /* |
2 | * This is a module which is used for logging packets to userspace via |
3 | * nfetlink. |
4 | * |
5 | * (C) 2005 by Harald Welte <laforge@netfilter.org> |
6 | * |
7 | * Based on the old ipv4-only ipt_ULOG.c: |
8 | * (C) 2000-2004 by Harald Welte <laforge@netfilter.org> |
9 | * |
10 | * This program is free software; you can redistribute it and/or modify |
11 | * it under the terms of the GNU General Public License version 2 as |
12 | * published by the Free Software Foundation. |
13 | */ |
14 | #include <linux/module.h> |
15 | #include <linux/skbuff.h> |
16 | #include <linux/init.h> |
17 | #include <linux/ip.h> |
18 | #include <linux/ipv6.h> |
19 | #include <linux/netdevice.h> |
20 | #include <linux/netfilter.h> |
21 | #include <linux/netlink.h> |
22 | #include <linux/netfilter/nfnetlink.h> |
23 | #include <linux/netfilter/nfnetlink_log.h> |
24 | #include <linux/spinlock.h> |
25 | #include <linux/sysctl.h> |
26 | #include <linux/proc_fs.h> |
27 | #include <linux/security.h> |
28 | #include <linux/list.h> |
29 | #include <linux/jhash.h> |
30 | #include <linux/random.h> |
31 | #include <linux/slab.h> |
32 | #include <net/sock.h> |
33 | #include <net/netfilter/nf_log.h> |
34 | #include <net/netfilter/nfnetlink_log.h> |
35 | |
36 | #include <asm/atomic.h> |
37 | |
38 | #ifdef CONFIG_BRIDGE_NETFILTER |
39 | #include "../bridge/br_private.h" |
40 | #endif |
41 | |
42 | #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE |
43 | #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ |
44 | #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ |
45 | #define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */ |
46 | |
47 | #define PRINTR(x, args...) do { if (net_ratelimit()) \ |
48 | printk(x, ## args); } while (0); |
49 | |
50 | struct nfulnl_instance { |
51 | struct hlist_node hlist; /* global list of instances */ |
52 | spinlock_t lock; |
53 | atomic_t use; /* use count */ |
54 | |
55 | unsigned int qlen; /* number of nlmsgs in skb */ |
56 | struct sk_buff *skb; /* pre-allocatd skb */ |
57 | struct timer_list timer; |
58 | int peer_pid; /* PID of the peer process */ |
59 | |
60 | /* configurable parameters */ |
61 | unsigned int flushtimeout; /* timeout until queue flush */ |
62 | unsigned int nlbufsiz; /* netlink buffer allocation size */ |
63 | unsigned int qthreshold; /* threshold of the queue */ |
64 | u_int32_t copy_range; |
65 | u_int32_t seq; /* instance-local sequential counter */ |
66 | u_int16_t group_num; /* number of this queue */ |
67 | u_int16_t flags; |
68 | u_int8_t copy_mode; |
69 | }; |
70 | |
71 | static DEFINE_RWLOCK(instances_lock); |
72 | static atomic_t global_seq; |
73 | |
74 | #define INSTANCE_BUCKETS 16 |
75 | static struct hlist_head instance_table[INSTANCE_BUCKETS]; |
76 | static unsigned int hash_init; |
77 | |
78 | static inline u_int8_t instance_hashfn(u_int16_t group_num) |
79 | { |
80 | return ((group_num & 0xff) % INSTANCE_BUCKETS); |
81 | } |
82 | |
83 | static struct nfulnl_instance * |
84 | __instance_lookup(u_int16_t group_num) |
85 | { |
86 | struct hlist_head *head; |
87 | struct hlist_node *pos; |
88 | struct nfulnl_instance *inst; |
89 | |
90 | head = &instance_table[instance_hashfn(group_num)]; |
91 | hlist_for_each_entry(inst, pos, head, hlist) { |
92 | if (inst->group_num == group_num) |
93 | return inst; |
94 | } |
95 | return NULL; |
96 | } |
97 | |
98 | static inline void |
99 | instance_get(struct nfulnl_instance *inst) |
100 | { |
101 | atomic_inc(&inst->use); |
102 | } |
103 | |
104 | static struct nfulnl_instance * |
105 | instance_lookup_get(u_int16_t group_num) |
106 | { |
107 | struct nfulnl_instance *inst; |
108 | |
109 | read_lock_bh(&instances_lock); |
110 | inst = __instance_lookup(group_num); |
111 | if (inst) |
112 | instance_get(inst); |
113 | read_unlock_bh(&instances_lock); |
114 | |
115 | return inst; |
116 | } |
117 | |
118 | static void |
119 | instance_put(struct nfulnl_instance *inst) |
120 | { |
121 | if (inst && atomic_dec_and_test(&inst->use)) { |
122 | kfree(inst); |
123 | module_put(THIS_MODULE); |
124 | } |
125 | } |
126 | |
127 | static void nfulnl_timer(unsigned long data); |
128 | |
129 | static struct nfulnl_instance * |
130 | instance_create(u_int16_t group_num, int pid) |
131 | { |
132 | struct nfulnl_instance *inst; |
133 | int err; |
134 | |
135 | write_lock_bh(&instances_lock); |
136 | if (__instance_lookup(group_num)) { |
137 | err = -EEXIST; |
138 | goto out_unlock; |
139 | } |
140 | |
141 | inst = kzalloc(sizeof(*inst), GFP_ATOMIC); |
142 | if (!inst) { |
143 | err = -ENOMEM; |
144 | goto out_unlock; |
145 | } |
146 | |
147 | if (!try_module_get(THIS_MODULE)) { |
148 | kfree(inst); |
149 | err = -EAGAIN; |
150 | goto out_unlock; |
151 | } |
152 | |
153 | INIT_HLIST_NODE(&inst->hlist); |
154 | spin_lock_init(&inst->lock); |
155 | /* needs to be two, since we _put() after creation */ |
156 | atomic_set(&inst->use, 2); |
157 | |
158 | setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst); |
159 | |
160 | inst->peer_pid = pid; |
161 | inst->group_num = group_num; |
162 | |
163 | inst->qthreshold = NFULNL_QTHRESH_DEFAULT; |
164 | inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT; |
165 | inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT; |
166 | inst->copy_mode = NFULNL_COPY_PACKET; |
167 | inst->copy_range = NFULNL_COPY_RANGE_MAX; |
168 | |
169 | hlist_add_head(&inst->hlist, |
170 | &instance_table[instance_hashfn(group_num)]); |
171 | |
172 | write_unlock_bh(&instances_lock); |
173 | |
174 | return inst; |
175 | |
176 | out_unlock: |
177 | write_unlock_bh(&instances_lock); |
178 | return ERR_PTR(err); |
179 | } |
180 | |
181 | static void __nfulnl_flush(struct nfulnl_instance *inst); |
182 | |
183 | static void |
184 | __instance_destroy(struct nfulnl_instance *inst) |
185 | { |
186 | /* first pull it out of the global list */ |
187 | hlist_del(&inst->hlist); |
188 | |
189 | /* then flush all pending packets from skb */ |
190 | |
191 | spin_lock_bh(&inst->lock); |
192 | if (inst->skb) |
193 | __nfulnl_flush(inst); |
194 | spin_unlock_bh(&inst->lock); |
195 | |
196 | /* and finally put the refcount */ |
197 | instance_put(inst); |
198 | } |
199 | |
200 | static inline void |
201 | instance_destroy(struct nfulnl_instance *inst) |
202 | { |
203 | write_lock_bh(&instances_lock); |
204 | __instance_destroy(inst); |
205 | write_unlock_bh(&instances_lock); |
206 | } |
207 | |
208 | static int |
209 | nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, |
210 | unsigned int range) |
211 | { |
212 | int status = 0; |
213 | |
214 | spin_lock_bh(&inst->lock); |
215 | |
216 | switch (mode) { |
217 | case NFULNL_COPY_NONE: |
218 | case NFULNL_COPY_META: |
219 | inst->copy_mode = mode; |
220 | inst->copy_range = 0; |
221 | break; |
222 | |
223 | case NFULNL_COPY_PACKET: |
224 | inst->copy_mode = mode; |
225 | inst->copy_range = min_t(unsigned int, |
226 | range, NFULNL_COPY_RANGE_MAX); |
227 | break; |
228 | |
229 | default: |
230 | status = -EINVAL; |
231 | break; |
232 | } |
233 | |
234 | spin_unlock_bh(&inst->lock); |
235 | |
236 | return status; |
237 | } |
238 | |
239 | static int |
240 | nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz) |
241 | { |
242 | int status; |
243 | |
244 | spin_lock_bh(&inst->lock); |
245 | if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT) |
246 | status = -ERANGE; |
247 | else if (nlbufsiz > 131072) |
248 | status = -ERANGE; |
249 | else { |
250 | inst->nlbufsiz = nlbufsiz; |
251 | status = 0; |
252 | } |
253 | spin_unlock_bh(&inst->lock); |
254 | |
255 | return status; |
256 | } |
257 | |
258 | static int |
259 | nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout) |
260 | { |
261 | spin_lock_bh(&inst->lock); |
262 | inst->flushtimeout = timeout; |
263 | spin_unlock_bh(&inst->lock); |
264 | |
265 | return 0; |
266 | } |
267 | |
268 | static int |
269 | nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh) |
270 | { |
271 | spin_lock_bh(&inst->lock); |
272 | inst->qthreshold = qthresh; |
273 | spin_unlock_bh(&inst->lock); |
274 | |
275 | return 0; |
276 | } |
277 | |
278 | static int |
279 | nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags) |
280 | { |
281 | spin_lock_bh(&inst->lock); |
282 | inst->flags = flags; |
283 | spin_unlock_bh(&inst->lock); |
284 | |
285 | return 0; |
286 | } |
287 | |
288 | static struct sk_buff * |
289 | nfulnl_alloc_skb(unsigned int inst_size, unsigned int pkt_size) |
290 | { |
291 | struct sk_buff *skb; |
292 | unsigned int n; |
293 | |
294 | /* alloc skb which should be big enough for a whole multipart |
295 | * message. WARNING: has to be <= 128k due to slab restrictions */ |
296 | |
297 | n = max(inst_size, pkt_size); |
298 | skb = alloc_skb(n, GFP_ATOMIC); |
299 | if (!skb) { |
300 | PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n", |
301 | inst_size); |
302 | |
303 | if (n > pkt_size) { |
304 | /* try to allocate only as much as we need for current |
305 | * packet */ |
306 | |
307 | skb = alloc_skb(pkt_size, GFP_ATOMIC); |
308 | if (!skb) |
309 | PRINTR("nfnetlink_log: can't even alloc %u " |
310 | "bytes\n", pkt_size); |
311 | } |
312 | } |
313 | |
314 | return skb; |
315 | } |
316 | |
317 | static int |
318 | __nfulnl_send(struct nfulnl_instance *inst) |
319 | { |
320 | int status = -1; |
321 | |
322 | if (inst->qlen > 1) |
323 | NLMSG_PUT(inst->skb, 0, 0, |
324 | NLMSG_DONE, |
325 | sizeof(struct nfgenmsg)); |
326 | |
327 | status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid, |
328 | MSG_DONTWAIT); |
329 | |
330 | inst->qlen = 0; |
331 | inst->skb = NULL; |
332 | |
333 | nlmsg_failure: |
334 | return status; |
335 | } |
336 | |
337 | static void |
338 | __nfulnl_flush(struct nfulnl_instance *inst) |
339 | { |
340 | /* timer holds a reference */ |
341 | if (del_timer(&inst->timer)) |
342 | instance_put(inst); |
343 | if (inst->skb) |
344 | __nfulnl_send(inst); |
345 | } |
346 | |
347 | static void |
348 | nfulnl_timer(unsigned long data) |
349 | { |
350 | struct nfulnl_instance *inst = (struct nfulnl_instance *)data; |
351 | |
352 | spin_lock_bh(&inst->lock); |
353 | if (inst->skb) |
354 | __nfulnl_send(inst); |
355 | spin_unlock_bh(&inst->lock); |
356 | instance_put(inst); |
357 | } |
358 | |
359 | /* This is an inline function, we don't really care about a long |
360 | * list of arguments */ |
361 | static inline int |
362 | __build_packet_message(struct nfulnl_instance *inst, |
363 | const struct sk_buff *skb, |
364 | unsigned int data_len, |
365 | u_int8_t pf, |
366 | unsigned int hooknum, |
367 | const struct net_device *indev, |
368 | const struct net_device *outdev, |
369 | const struct nf_loginfo *li, |
370 | const char *prefix, unsigned int plen) |
371 | { |
372 | struct nfulnl_msg_packet_hdr pmsg; |
373 | struct nlmsghdr *nlh; |
374 | struct nfgenmsg *nfmsg; |
375 | __be32 tmp_uint; |
376 | sk_buff_data_t old_tail = inst->skb->tail; |
377 | |
378 | nlh = NLMSG_PUT(inst->skb, 0, 0, |
379 | NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET, |
380 | sizeof(struct nfgenmsg)); |
381 | nfmsg = NLMSG_DATA(nlh); |
382 | nfmsg->nfgen_family = pf; |
383 | nfmsg->version = NFNETLINK_V0; |
384 | nfmsg->res_id = htons(inst->group_num); |
385 | |
386 | pmsg.hw_protocol = skb->protocol; |
387 | pmsg.hook = hooknum; |
388 | |
389 | NLA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg); |
390 | |
391 | if (prefix) |
392 | NLA_PUT(inst->skb, NFULA_PREFIX, plen, prefix); |
393 | |
394 | if (indev) { |
395 | #ifndef CONFIG_BRIDGE_NETFILTER |
396 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV, |
397 | htonl(indev->ifindex)); |
398 | #else |
399 | if (pf == PF_BRIDGE) { |
400 | /* Case 1: outdev is physical input device, we need to |
401 | * look for bridge group (when called from |
402 | * netfilter_bridge) */ |
403 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV, |
404 | htonl(indev->ifindex)); |
405 | /* this is the bridge group "brX" */ |
406 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV, |
407 | htonl(indev->br_port->br->dev->ifindex)); |
408 | } else { |
409 | /* Case 2: indev is bridge group, we need to look for |
410 | * physical device (when called from ipv4) */ |
411 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_INDEV, |
412 | htonl(indev->ifindex)); |
413 | if (skb->nf_bridge && skb->nf_bridge->physindev) |
414 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSINDEV, |
415 | htonl(skb->nf_bridge->physindev->ifindex)); |
416 | } |
417 | #endif |
418 | } |
419 | |
420 | if (outdev) { |
421 | tmp_uint = htonl(outdev->ifindex); |
422 | #ifndef CONFIG_BRIDGE_NETFILTER |
423 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV, |
424 | htonl(outdev->ifindex)); |
425 | #else |
426 | if (pf == PF_BRIDGE) { |
427 | /* Case 1: outdev is physical output device, we need to |
428 | * look for bridge group (when called from |
429 | * netfilter_bridge) */ |
430 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, |
431 | htonl(outdev->ifindex)); |
432 | /* this is the bridge group "brX" */ |
433 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV, |
434 | htonl(outdev->br_port->br->dev->ifindex)); |
435 | } else { |
436 | /* Case 2: indev is a bridge group, we need to look |
437 | * for physical device (when called from ipv4) */ |
438 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_OUTDEV, |
439 | htonl(outdev->ifindex)); |
440 | if (skb->nf_bridge && skb->nf_bridge->physoutdev) |
441 | NLA_PUT_BE32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV, |
442 | htonl(skb->nf_bridge->physoutdev->ifindex)); |
443 | } |
444 | #endif |
445 | } |
446 | |
447 | if (skb->mark) |
448 | NLA_PUT_BE32(inst->skb, NFULA_MARK, htonl(skb->mark)); |
449 | |
450 | if (indev && skb->dev) { |
451 | struct nfulnl_msg_packet_hw phw; |
452 | int len = dev_parse_header(skb, phw.hw_addr); |
453 | if (len > 0) { |
454 | phw.hw_addrlen = htons(len); |
455 | NLA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw); |
456 | } |
457 | } |
458 | |
459 | if (indev && skb_mac_header_was_set(skb)) { |
460 | NLA_PUT_BE16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)); |
461 | NLA_PUT_BE16(inst->skb, NFULA_HWLEN, |
462 | htons(skb->dev->hard_header_len)); |
463 | NLA_PUT(inst->skb, NFULA_HWHEADER, skb->dev->hard_header_len, |
464 | skb_mac_header(skb)); |
465 | } |
466 | |
467 | if (skb->tstamp.tv64) { |
468 | struct nfulnl_msg_packet_timestamp ts; |
469 | struct timeval tv = ktime_to_timeval(skb->tstamp); |
470 | ts.sec = cpu_to_be64(tv.tv_sec); |
471 | ts.usec = cpu_to_be64(tv.tv_usec); |
472 | |
473 | NLA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts); |
474 | } |
475 | |
476 | /* UID */ |
477 | if (skb->sk) { |
478 | read_lock_bh(&skb->sk->sk_callback_lock); |
479 | if (skb->sk->sk_socket && skb->sk->sk_socket->file) { |
480 | struct file *file = skb->sk->sk_socket->file; |
481 | __be32 uid = htonl(file->f_cred->fsuid); |
482 | __be32 gid = htonl(file->f_cred->fsgid); |
483 | /* need to unlock here since NLA_PUT may goto */ |
484 | read_unlock_bh(&skb->sk->sk_callback_lock); |
485 | NLA_PUT_BE32(inst->skb, NFULA_UID, uid); |
486 | NLA_PUT_BE32(inst->skb, NFULA_GID, gid); |
487 | } else |
488 | read_unlock_bh(&skb->sk->sk_callback_lock); |
489 | } |
490 | |
491 | /* local sequence number */ |
492 | if (inst->flags & NFULNL_CFG_F_SEQ) |
493 | NLA_PUT_BE32(inst->skb, NFULA_SEQ, htonl(inst->seq++)); |
494 | |
495 | /* global sequence number */ |
496 | if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) |
497 | NLA_PUT_BE32(inst->skb, NFULA_SEQ_GLOBAL, |
498 | htonl(atomic_inc_return(&global_seq))); |
499 | |
500 | if (data_len) { |
501 | struct nlattr *nla; |
502 | int size = nla_attr_size(data_len); |
503 | |
504 | if (skb_tailroom(inst->skb) < nla_total_size(data_len)) { |
505 | printk(KERN_WARNING "nfnetlink_log: no tailroom!\n"); |
506 | goto nlmsg_failure; |
507 | } |
508 | |
509 | nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len)); |
510 | nla->nla_type = NFULA_PAYLOAD; |
511 | nla->nla_len = size; |
512 | |
513 | if (skb_copy_bits(skb, 0, nla_data(nla), data_len)) |
514 | BUG(); |
515 | } |
516 | |
517 | nlh->nlmsg_len = inst->skb->tail - old_tail; |
518 | return 0; |
519 | |
520 | nlmsg_failure: |
521 | nla_put_failure: |
522 | PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n"); |
523 | return -1; |
524 | } |
525 | |
526 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) |
527 | |
528 | static struct nf_loginfo default_loginfo = { |
529 | .type = NF_LOG_TYPE_ULOG, |
530 | .u = { |
531 | .ulog = { |
532 | .copy_len = 0xffff, |
533 | .group = 0, |
534 | .qthreshold = 1, |
535 | }, |
536 | }, |
537 | }; |
538 | |
539 | /* log handler for internal netfilter logging api */ |
540 | void |
541 | nfulnl_log_packet(u_int8_t pf, |
542 | unsigned int hooknum, |
543 | const struct sk_buff *skb, |
544 | const struct net_device *in, |
545 | const struct net_device *out, |
546 | const struct nf_loginfo *li_user, |
547 | const char *prefix) |
548 | { |
549 | unsigned int size, data_len; |
550 | struct nfulnl_instance *inst; |
551 | const struct nf_loginfo *li; |
552 | unsigned int qthreshold; |
553 | unsigned int plen; |
554 | |
555 | if (li_user && li_user->type == NF_LOG_TYPE_ULOG) |
556 | li = li_user; |
557 | else |
558 | li = &default_loginfo; |
559 | |
560 | inst = instance_lookup_get(li->u.ulog.group); |
561 | if (!inst) |
562 | return; |
563 | |
564 | plen = 0; |
565 | if (prefix) |
566 | plen = strlen(prefix) + 1; |
567 | |
568 | /* FIXME: do we want to make the size calculation conditional based on |
569 | * what is actually present? way more branches and checks, but more |
570 | * memory efficient... */ |
571 | size = NLMSG_SPACE(sizeof(struct nfgenmsg)) |
572 | + nla_total_size(sizeof(struct nfulnl_msg_packet_hdr)) |
573 | + nla_total_size(sizeof(u_int32_t)) /* ifindex */ |
574 | + nla_total_size(sizeof(u_int32_t)) /* ifindex */ |
575 | #ifdef CONFIG_BRIDGE_NETFILTER |
576 | + nla_total_size(sizeof(u_int32_t)) /* ifindex */ |
577 | + nla_total_size(sizeof(u_int32_t)) /* ifindex */ |
578 | #endif |
579 | + nla_total_size(sizeof(u_int32_t)) /* mark */ |
580 | + nla_total_size(sizeof(u_int32_t)) /* uid */ |
581 | + nla_total_size(sizeof(u_int32_t)) /* gid */ |
582 | + nla_total_size(plen) /* prefix */ |
583 | + nla_total_size(sizeof(struct nfulnl_msg_packet_hw)) |
584 | + nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp)); |
585 | |
586 | if (in && skb_mac_header_was_set(skb)) { |
587 | size += nla_total_size(skb->dev->hard_header_len) |
588 | + nla_total_size(sizeof(u_int16_t)) /* hwtype */ |
589 | + nla_total_size(sizeof(u_int16_t)); /* hwlen */ |
590 | } |
591 | |
592 | spin_lock_bh(&inst->lock); |
593 | |
594 | if (inst->flags & NFULNL_CFG_F_SEQ) |
595 | size += nla_total_size(sizeof(u_int32_t)); |
596 | if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) |
597 | size += nla_total_size(sizeof(u_int32_t)); |
598 | |
599 | qthreshold = inst->qthreshold; |
600 | /* per-rule qthreshold overrides per-instance */ |
601 | if (li->u.ulog.qthreshold) |
602 | if (qthreshold > li->u.ulog.qthreshold) |
603 | qthreshold = li->u.ulog.qthreshold; |
604 | |
605 | |
606 | switch (inst->copy_mode) { |
607 | case NFULNL_COPY_META: |
608 | case NFULNL_COPY_NONE: |
609 | data_len = 0; |
610 | break; |
611 | |
612 | case NFULNL_COPY_PACKET: |
613 | if (inst->copy_range == 0 |
614 | || inst->copy_range > skb->len) |
615 | data_len = skb->len; |
616 | else |
617 | data_len = inst->copy_range; |
618 | |
619 | size += nla_total_size(data_len); |
620 | break; |
621 | |
622 | default: |
623 | goto unlock_and_release; |
624 | } |
625 | |
626 | if (inst->skb && |
627 | size > skb_tailroom(inst->skb) - sizeof(struct nfgenmsg)) { |
628 | /* either the queue len is too high or we don't have |
629 | * enough room in the skb left. flush to userspace. */ |
630 | __nfulnl_flush(inst); |
631 | } |
632 | |
633 | if (!inst->skb) { |
634 | inst->skb = nfulnl_alloc_skb(inst->nlbufsiz, size); |
635 | if (!inst->skb) |
636 | goto alloc_failure; |
637 | } |
638 | |
639 | inst->qlen++; |
640 | |
641 | __build_packet_message(inst, skb, data_len, pf, |
642 | hooknum, in, out, li, prefix, plen); |
643 | |
644 | if (inst->qlen >= qthreshold) |
645 | __nfulnl_flush(inst); |
646 | /* timer_pending always called within inst->lock, so there |
647 | * is no chance of a race here */ |
648 | else if (!timer_pending(&inst->timer)) { |
649 | instance_get(inst); |
650 | inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100); |
651 | add_timer(&inst->timer); |
652 | } |
653 | |
654 | unlock_and_release: |
655 | spin_unlock_bh(&inst->lock); |
656 | instance_put(inst); |
657 | return; |
658 | |
659 | alloc_failure: |
660 | /* FIXME: statistics */ |
661 | goto unlock_and_release; |
662 | } |
663 | EXPORT_SYMBOL_GPL(nfulnl_log_packet); |
664 | |
665 | static int |
666 | nfulnl_rcv_nl_event(struct notifier_block *this, |
667 | unsigned long event, void *ptr) |
668 | { |
669 | struct netlink_notify *n = ptr; |
670 | |
671 | if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { |
672 | int i; |
673 | |
674 | /* destroy all instances for this pid */ |
675 | write_lock_bh(&instances_lock); |
676 | for (i = 0; i < INSTANCE_BUCKETS; i++) { |
677 | struct hlist_node *tmp, *t2; |
678 | struct nfulnl_instance *inst; |
679 | struct hlist_head *head = &instance_table[i]; |
680 | |
681 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { |
682 | if ((net_eq(n->net, &init_net)) && |
683 | (n->pid == inst->peer_pid)) |
684 | __instance_destroy(inst); |
685 | } |
686 | } |
687 | write_unlock_bh(&instances_lock); |
688 | } |
689 | return NOTIFY_DONE; |
690 | } |
691 | |
692 | static struct notifier_block nfulnl_rtnl_notifier = { |
693 | .notifier_call = nfulnl_rcv_nl_event, |
694 | }; |
695 | |
696 | static int |
697 | nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, |
698 | const struct nlmsghdr *nlh, |
699 | const struct nlattr * const nfqa[]) |
700 | { |
701 | return -ENOTSUPP; |
702 | } |
703 | |
704 | static struct nf_logger nfulnl_logger __read_mostly = { |
705 | .name = "nfnetlink_log", |
706 | .logfn = &nfulnl_log_packet, |
707 | .me = THIS_MODULE, |
708 | }; |
709 | |
710 | static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = { |
711 | [NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) }, |
712 | [NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) }, |
713 | [NFULA_CFG_TIMEOUT] = { .type = NLA_U32 }, |
714 | [NFULA_CFG_QTHRESH] = { .type = NLA_U32 }, |
715 | [NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 }, |
716 | [NFULA_CFG_FLAGS] = { .type = NLA_U16 }, |
717 | }; |
718 | |
719 | static int |
720 | nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb, |
721 | const struct nlmsghdr *nlh, |
722 | const struct nlattr * const nfula[]) |
723 | { |
724 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); |
725 | u_int16_t group_num = ntohs(nfmsg->res_id); |
726 | struct nfulnl_instance *inst; |
727 | struct nfulnl_msg_config_cmd *cmd = NULL; |
728 | int ret = 0; |
729 | |
730 | if (nfula[NFULA_CFG_CMD]) { |
731 | u_int8_t pf = nfmsg->nfgen_family; |
732 | cmd = nla_data(nfula[NFULA_CFG_CMD]); |
733 | |
734 | /* Commands without queue context */ |
735 | switch (cmd->command) { |
736 | case NFULNL_CFG_CMD_PF_BIND: |
737 | return nf_log_bind_pf(pf, &nfulnl_logger); |
738 | case NFULNL_CFG_CMD_PF_UNBIND: |
739 | nf_log_unbind_pf(pf); |
740 | return 0; |
741 | } |
742 | } |
743 | |
744 | inst = instance_lookup_get(group_num); |
745 | if (inst && inst->peer_pid != NETLINK_CB(skb).pid) { |
746 | ret = -EPERM; |
747 | goto out_put; |
748 | } |
749 | |
750 | if (cmd != NULL) { |
751 | switch (cmd->command) { |
752 | case NFULNL_CFG_CMD_BIND: |
753 | if (inst) { |
754 | ret = -EBUSY; |
755 | goto out_put; |
756 | } |
757 | |
758 | inst = instance_create(group_num, |
759 | NETLINK_CB(skb).pid); |
760 | if (IS_ERR(inst)) { |
761 | ret = PTR_ERR(inst); |
762 | goto out; |
763 | } |
764 | break; |
765 | case NFULNL_CFG_CMD_UNBIND: |
766 | if (!inst) { |
767 | ret = -ENODEV; |
768 | goto out; |
769 | } |
770 | |
771 | instance_destroy(inst); |
772 | goto out_put; |
773 | default: |
774 | ret = -ENOTSUPP; |
775 | break; |
776 | } |
777 | } |
778 | |
779 | if (nfula[NFULA_CFG_MODE]) { |
780 | struct nfulnl_msg_config_mode *params; |
781 | params = nla_data(nfula[NFULA_CFG_MODE]); |
782 | |
783 | if (!inst) { |
784 | ret = -ENODEV; |
785 | goto out; |
786 | } |
787 | nfulnl_set_mode(inst, params->copy_mode, |
788 | ntohl(params->copy_range)); |
789 | } |
790 | |
791 | if (nfula[NFULA_CFG_TIMEOUT]) { |
792 | __be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]); |
793 | |
794 | if (!inst) { |
795 | ret = -ENODEV; |
796 | goto out; |
797 | } |
798 | nfulnl_set_timeout(inst, ntohl(timeout)); |
799 | } |
800 | |
801 | if (nfula[NFULA_CFG_NLBUFSIZ]) { |
802 | __be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]); |
803 | |
804 | if (!inst) { |
805 | ret = -ENODEV; |
806 | goto out; |
807 | } |
808 | nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz)); |
809 | } |
810 | |
811 | if (nfula[NFULA_CFG_QTHRESH]) { |
812 | __be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]); |
813 | |
814 | if (!inst) { |
815 | ret = -ENODEV; |
816 | goto out; |
817 | } |
818 | nfulnl_set_qthresh(inst, ntohl(qthresh)); |
819 | } |
820 | |
821 | if (nfula[NFULA_CFG_FLAGS]) { |
822 | __be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]); |
823 | |
824 | if (!inst) { |
825 | ret = -ENODEV; |
826 | goto out; |
827 | } |
828 | nfulnl_set_flags(inst, ntohs(flags)); |
829 | } |
830 | |
831 | out_put: |
832 | instance_put(inst); |
833 | out: |
834 | return ret; |
835 | } |
836 | |
837 | static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = { |
838 | [NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp, |
839 | .attr_count = NFULA_MAX, }, |
840 | [NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config, |
841 | .attr_count = NFULA_CFG_MAX, |
842 | .policy = nfula_cfg_policy }, |
843 | }; |
844 | |
845 | static const struct nfnetlink_subsystem nfulnl_subsys = { |
846 | .name = "log", |
847 | .subsys_id = NFNL_SUBSYS_ULOG, |
848 | .cb_count = NFULNL_MSG_MAX, |
849 | .cb = nfulnl_cb, |
850 | }; |
851 | |
852 | #ifdef CONFIG_PROC_FS |
853 | struct iter_state { |
854 | unsigned int bucket; |
855 | }; |
856 | |
857 | static struct hlist_node *get_first(struct iter_state *st) |
858 | { |
859 | if (!st) |
860 | return NULL; |
861 | |
862 | for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { |
863 | if (!hlist_empty(&instance_table[st->bucket])) |
864 | return instance_table[st->bucket].first; |
865 | } |
866 | return NULL; |
867 | } |
868 | |
869 | static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h) |
870 | { |
871 | h = h->next; |
872 | while (!h) { |
873 | if (++st->bucket >= INSTANCE_BUCKETS) |
874 | return NULL; |
875 | |
876 | h = instance_table[st->bucket].first; |
877 | } |
878 | return h; |
879 | } |
880 | |
881 | static struct hlist_node *get_idx(struct iter_state *st, loff_t pos) |
882 | { |
883 | struct hlist_node *head; |
884 | head = get_first(st); |
885 | |
886 | if (head) |
887 | while (pos && (head = get_next(st, head))) |
888 | pos--; |
889 | return pos ? NULL : head; |
890 | } |
891 | |
892 | static void *seq_start(struct seq_file *seq, loff_t *pos) |
893 | __acquires(instances_lock) |
894 | { |
895 | read_lock_bh(&instances_lock); |
896 | return get_idx(seq->private, *pos); |
897 | } |
898 | |
899 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) |
900 | { |
901 | (*pos)++; |
902 | return get_next(s->private, v); |
903 | } |
904 | |
905 | static void seq_stop(struct seq_file *s, void *v) |
906 | __releases(instances_lock) |
907 | { |
908 | read_unlock_bh(&instances_lock); |
909 | } |
910 | |
911 | static int seq_show(struct seq_file *s, void *v) |
912 | { |
913 | const struct nfulnl_instance *inst = v; |
914 | |
915 | return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n", |
916 | inst->group_num, |
917 | inst->peer_pid, inst->qlen, |
918 | inst->copy_mode, inst->copy_range, |
919 | inst->flushtimeout, atomic_read(&inst->use)); |
920 | } |
921 | |
922 | static const struct seq_operations nful_seq_ops = { |
923 | .start = seq_start, |
924 | .next = seq_next, |
925 | .stop = seq_stop, |
926 | .show = seq_show, |
927 | }; |
928 | |
929 | static int nful_open(struct inode *inode, struct file *file) |
930 | { |
931 | return seq_open_private(file, &nful_seq_ops, |
932 | sizeof(struct iter_state)); |
933 | } |
934 | |
935 | static const struct file_operations nful_file_ops = { |
936 | .owner = THIS_MODULE, |
937 | .open = nful_open, |
938 | .read = seq_read, |
939 | .llseek = seq_lseek, |
940 | .release = seq_release_private, |
941 | }; |
942 | |
943 | #endif /* PROC_FS */ |
944 | |
945 | static int __init nfnetlink_log_init(void) |
946 | { |
947 | int i, status = -ENOMEM; |
948 | |
949 | for (i = 0; i < INSTANCE_BUCKETS; i++) |
950 | INIT_HLIST_HEAD(&instance_table[i]); |
951 | |
952 | /* it's not really all that important to have a random value, so |
953 | * we can do this from the init function, even if there hasn't |
954 | * been that much entropy yet */ |
955 | get_random_bytes(&hash_init, sizeof(hash_init)); |
956 | |
957 | netlink_register_notifier(&nfulnl_rtnl_notifier); |
958 | status = nfnetlink_subsys_register(&nfulnl_subsys); |
959 | if (status < 0) { |
960 | printk(KERN_ERR "log: failed to create netlink socket\n"); |
961 | goto cleanup_netlink_notifier; |
962 | } |
963 | |
964 | status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger); |
965 | if (status < 0) { |
966 | printk(KERN_ERR "log: failed to register logger\n"); |
967 | goto cleanup_subsys; |
968 | } |
969 | |
970 | #ifdef CONFIG_PROC_FS |
971 | if (!proc_create("nfnetlink_log", 0440, |
972 | proc_net_netfilter, &nful_file_ops)) |
973 | goto cleanup_logger; |
974 | #endif |
975 | return status; |
976 | |
977 | #ifdef CONFIG_PROC_FS |
978 | cleanup_logger: |
979 | nf_log_unregister(&nfulnl_logger); |
980 | #endif |
981 | cleanup_subsys: |
982 | nfnetlink_subsys_unregister(&nfulnl_subsys); |
983 | cleanup_netlink_notifier: |
984 | netlink_unregister_notifier(&nfulnl_rtnl_notifier); |
985 | return status; |
986 | } |
987 | |
988 | static void __exit nfnetlink_log_fini(void) |
989 | { |
990 | nf_log_unregister(&nfulnl_logger); |
991 | #ifdef CONFIG_PROC_FS |
992 | remove_proc_entry("nfnetlink_log", proc_net_netfilter); |
993 | #endif |
994 | nfnetlink_subsys_unregister(&nfulnl_subsys); |
995 | netlink_unregister_notifier(&nfulnl_rtnl_notifier); |
996 | } |
997 | |
998 | MODULE_DESCRIPTION("netfilter userspace logging"); |
999 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
1000 | MODULE_LICENSE("GPL"); |
1001 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG); |
1002 | |
1003 | module_init(nfnetlink_log_init); |
1004 | module_exit(nfnetlink_log_fini); |
1005 |
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