i40e: fix shift precedence issue
[linux-2.6/btrfs-unstable.git] / net / netfilter / nfnetlink_cttimeout.c
blob476accd171452fcfbfbe01018dcadd55fee41f67
1 /*
2 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
3 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation (or any later at your option).
8 */
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/rculist.h>
13 #include <linux/rculist_nulls.h>
14 #include <linux/types.h>
15 #include <linux/timer.h>
16 #include <linux/security.h>
17 #include <linux/skbuff.h>
18 #include <linux/errno.h>
19 #include <linux/netlink.h>
20 #include <linux/spinlock.h>
21 #include <linux/interrupt.h>
22 #include <linux/slab.h>
24 #include <linux/netfilter.h>
25 #include <net/netlink.h>
26 #include <net/sock.h>
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_core.h>
29 #include <net/netfilter/nf_conntrack_l3proto.h>
30 #include <net/netfilter/nf_conntrack_l4proto.h>
31 #include <net/netfilter/nf_conntrack_tuple.h>
32 #include <net/netfilter/nf_conntrack_timeout.h>
34 #include <linux/netfilter/nfnetlink.h>
35 #include <linux/netfilter/nfnetlink_cttimeout.h>
37 MODULE_LICENSE("GPL");
38 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
39 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
41 static LIST_HEAD(cttimeout_list);
43 static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
44 [CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
45 .len = CTNL_TIMEOUT_NAME_MAX - 1},
46 [CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
47 [CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
48 [CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
51 static int
52 ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
53 struct net *net, const struct nlattr *attr)
55 int ret = 0;
57 if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
58 struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
60 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
61 attr, l4proto->ctnl_timeout.nla_policy);
62 if (ret < 0)
63 return ret;
65 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
67 return ret;
70 static int
71 cttimeout_new_timeout(struct sock *ctnl, struct sk_buff *skb,
72 const struct nlmsghdr *nlh,
73 const struct nlattr * const cda[])
75 __u16 l3num;
76 __u8 l4num;
77 struct nf_conntrack_l4proto *l4proto;
78 struct ctnl_timeout *timeout, *matching = NULL;
79 struct net *net = sock_net(skb->sk);
80 char *name;
81 int ret;
83 if (!cda[CTA_TIMEOUT_NAME] ||
84 !cda[CTA_TIMEOUT_L3PROTO] ||
85 !cda[CTA_TIMEOUT_L4PROTO] ||
86 !cda[CTA_TIMEOUT_DATA])
87 return -EINVAL;
89 name = nla_data(cda[CTA_TIMEOUT_NAME]);
90 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
91 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
93 list_for_each_entry(timeout, &cttimeout_list, head) {
94 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
95 continue;
97 if (nlh->nlmsg_flags & NLM_F_EXCL)
98 return -EEXIST;
100 matching = timeout;
101 break;
104 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
106 /* This protocol is not supportted, skip. */
107 if (l4proto->l4proto != l4num) {
108 ret = -EOPNOTSUPP;
109 goto err_proto_put;
112 if (matching) {
113 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
114 /* You cannot replace one timeout policy by another of
115 * different kind, sorry.
117 if (matching->l3num != l3num ||
118 matching->l4proto->l4proto != l4num) {
119 ret = -EINVAL;
120 goto err_proto_put;
123 ret = ctnl_timeout_parse_policy(&matching->data,
124 l4proto, net,
125 cda[CTA_TIMEOUT_DATA]);
126 return ret;
128 ret = -EBUSY;
129 goto err_proto_put;
132 timeout = kzalloc(sizeof(struct ctnl_timeout) +
133 l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
134 if (timeout == NULL) {
135 ret = -ENOMEM;
136 goto err_proto_put;
139 ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
140 cda[CTA_TIMEOUT_DATA]);
141 if (ret < 0)
142 goto err;
144 strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
145 timeout->l3num = l3num;
146 timeout->l4proto = l4proto;
147 atomic_set(&timeout->refcnt, 1);
148 list_add_tail_rcu(&timeout->head, &cttimeout_list);
150 return 0;
151 err:
152 kfree(timeout);
153 err_proto_put:
154 nf_ct_l4proto_put(l4proto);
155 return ret;
158 static int
159 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
160 int event, struct ctnl_timeout *timeout)
162 struct nlmsghdr *nlh;
163 struct nfgenmsg *nfmsg;
164 unsigned int flags = portid ? NLM_F_MULTI : 0;
165 struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
167 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
168 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
169 if (nlh == NULL)
170 goto nlmsg_failure;
172 nfmsg = nlmsg_data(nlh);
173 nfmsg->nfgen_family = AF_UNSPEC;
174 nfmsg->version = NFNETLINK_V0;
175 nfmsg->res_id = 0;
177 if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
178 nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) ||
179 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) ||
180 nla_put_be32(skb, CTA_TIMEOUT_USE,
181 htonl(atomic_read(&timeout->refcnt))))
182 goto nla_put_failure;
184 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
185 struct nlattr *nest_parms;
186 int ret;
188 nest_parms = nla_nest_start(skb,
189 CTA_TIMEOUT_DATA | NLA_F_NESTED);
190 if (!nest_parms)
191 goto nla_put_failure;
193 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
194 if (ret < 0)
195 goto nla_put_failure;
197 nla_nest_end(skb, nest_parms);
200 nlmsg_end(skb, nlh);
201 return skb->len;
203 nlmsg_failure:
204 nla_put_failure:
205 nlmsg_cancel(skb, nlh);
206 return -1;
209 static int
210 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
212 struct ctnl_timeout *cur, *last;
214 if (cb->args[2])
215 return 0;
217 last = (struct ctnl_timeout *)cb->args[1];
218 if (cb->args[1])
219 cb->args[1] = 0;
221 rcu_read_lock();
222 list_for_each_entry_rcu(cur, &cttimeout_list, head) {
223 if (last) {
224 if (cur != last)
225 continue;
227 last = NULL;
229 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
230 cb->nlh->nlmsg_seq,
231 NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
232 IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
233 cb->args[1] = (unsigned long)cur;
234 break;
237 if (!cb->args[1])
238 cb->args[2] = 1;
239 rcu_read_unlock();
240 return skb->len;
243 static int
244 cttimeout_get_timeout(struct sock *ctnl, struct sk_buff *skb,
245 const struct nlmsghdr *nlh,
246 const struct nlattr * const cda[])
248 int ret = -ENOENT;
249 char *name;
250 struct ctnl_timeout *cur;
252 if (nlh->nlmsg_flags & NLM_F_DUMP) {
253 struct netlink_dump_control c = {
254 .dump = ctnl_timeout_dump,
256 return netlink_dump_start(ctnl, skb, nlh, &c);
259 if (!cda[CTA_TIMEOUT_NAME])
260 return -EINVAL;
261 name = nla_data(cda[CTA_TIMEOUT_NAME]);
263 list_for_each_entry(cur, &cttimeout_list, head) {
264 struct sk_buff *skb2;
266 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
267 continue;
269 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
270 if (skb2 == NULL) {
271 ret = -ENOMEM;
272 break;
275 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
276 nlh->nlmsg_seq,
277 NFNL_MSG_TYPE(nlh->nlmsg_type),
278 IPCTNL_MSG_TIMEOUT_NEW, cur);
279 if (ret <= 0) {
280 kfree_skb(skb2);
281 break;
283 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
284 MSG_DONTWAIT);
285 if (ret > 0)
286 ret = 0;
288 /* this avoids a loop in nfnetlink. */
289 return ret == -EAGAIN ? -ENOBUFS : ret;
291 return ret;
294 /* try to delete object, fail if it is still in use. */
295 static int ctnl_timeout_try_del(struct ctnl_timeout *timeout)
297 int ret = 0;
299 /* we want to avoid races with nf_ct_timeout_find_get. */
300 if (atomic_dec_and_test(&timeout->refcnt)) {
301 /* We are protected by nfnl mutex. */
302 list_del_rcu(&timeout->head);
303 nf_ct_l4proto_put(timeout->l4proto);
304 kfree_rcu(timeout, rcu_head);
305 } else {
306 /* still in use, restore reference counter. */
307 atomic_inc(&timeout->refcnt);
308 ret = -EBUSY;
310 return ret;
313 static int
314 cttimeout_del_timeout(struct sock *ctnl, struct sk_buff *skb,
315 const struct nlmsghdr *nlh,
316 const struct nlattr * const cda[])
318 char *name;
319 struct ctnl_timeout *cur;
320 int ret = -ENOENT;
322 if (!cda[CTA_TIMEOUT_NAME]) {
323 list_for_each_entry(cur, &cttimeout_list, head)
324 ctnl_timeout_try_del(cur);
326 return 0;
328 name = nla_data(cda[CTA_TIMEOUT_NAME]);
330 list_for_each_entry(cur, &cttimeout_list, head) {
331 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
332 continue;
334 ret = ctnl_timeout_try_del(cur);
335 if (ret < 0)
336 return ret;
338 break;
340 return ret;
343 static int
344 cttimeout_default_set(struct sock *ctnl, struct sk_buff *skb,
345 const struct nlmsghdr *nlh,
346 const struct nlattr * const cda[])
348 __u16 l3num;
349 __u8 l4num;
350 struct nf_conntrack_l4proto *l4proto;
351 struct net *net = sock_net(skb->sk);
352 unsigned int *timeouts;
353 int ret;
355 if (!cda[CTA_TIMEOUT_L3PROTO] ||
356 !cda[CTA_TIMEOUT_L4PROTO] ||
357 !cda[CTA_TIMEOUT_DATA])
358 return -EINVAL;
360 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
361 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
362 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
364 /* This protocol is not supported, skip. */
365 if (l4proto->l4proto != l4num) {
366 ret = -EOPNOTSUPP;
367 goto err;
370 timeouts = l4proto->get_timeouts(net);
372 ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
373 cda[CTA_TIMEOUT_DATA]);
374 if (ret < 0)
375 goto err;
377 nf_ct_l4proto_put(l4proto);
378 return 0;
379 err:
380 nf_ct_l4proto_put(l4proto);
381 return ret;
384 static int
385 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
386 u32 seq, u32 type, int event,
387 struct nf_conntrack_l4proto *l4proto)
389 struct nlmsghdr *nlh;
390 struct nfgenmsg *nfmsg;
391 unsigned int flags = portid ? NLM_F_MULTI : 0;
393 event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
394 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
395 if (nlh == NULL)
396 goto nlmsg_failure;
398 nfmsg = nlmsg_data(nlh);
399 nfmsg->nfgen_family = AF_UNSPEC;
400 nfmsg->version = NFNETLINK_V0;
401 nfmsg->res_id = 0;
403 if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
404 nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
405 goto nla_put_failure;
407 if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
408 struct nlattr *nest_parms;
409 unsigned int *timeouts = l4proto->get_timeouts(net);
410 int ret;
412 nest_parms = nla_nest_start(skb,
413 CTA_TIMEOUT_DATA | NLA_F_NESTED);
414 if (!nest_parms)
415 goto nla_put_failure;
417 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
418 if (ret < 0)
419 goto nla_put_failure;
421 nla_nest_end(skb, nest_parms);
424 nlmsg_end(skb, nlh);
425 return skb->len;
427 nlmsg_failure:
428 nla_put_failure:
429 nlmsg_cancel(skb, nlh);
430 return -1;
433 static int cttimeout_default_get(struct sock *ctnl, struct sk_buff *skb,
434 const struct nlmsghdr *nlh,
435 const struct nlattr * const cda[])
437 __u16 l3num;
438 __u8 l4num;
439 struct nf_conntrack_l4proto *l4proto;
440 struct net *net = sock_net(skb->sk);
441 struct sk_buff *skb2;
442 int ret, err;
444 if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
445 return -EINVAL;
447 l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
448 l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
449 l4proto = nf_ct_l4proto_find_get(l3num, l4num);
451 /* This protocol is not supported, skip. */
452 if (l4proto->l4proto != l4num) {
453 err = -EOPNOTSUPP;
454 goto err;
457 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
458 if (skb2 == NULL) {
459 err = -ENOMEM;
460 goto err;
463 ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
464 nlh->nlmsg_seq,
465 NFNL_MSG_TYPE(nlh->nlmsg_type),
466 IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
467 l4proto);
468 if (ret <= 0) {
469 kfree_skb(skb2);
470 err = -ENOMEM;
471 goto err;
473 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
474 if (ret > 0)
475 ret = 0;
477 /* this avoids a loop in nfnetlink. */
478 return ret == -EAGAIN ? -ENOBUFS : ret;
479 err:
480 nf_ct_l4proto_put(l4proto);
481 return err;
484 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
485 static struct ctnl_timeout *ctnl_timeout_find_get(const char *name)
487 struct ctnl_timeout *timeout, *matching = NULL;
489 rcu_read_lock();
490 list_for_each_entry_rcu(timeout, &cttimeout_list, head) {
491 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
492 continue;
494 if (!try_module_get(THIS_MODULE))
495 goto err;
497 if (!atomic_inc_not_zero(&timeout->refcnt)) {
498 module_put(THIS_MODULE);
499 goto err;
501 matching = timeout;
502 break;
504 err:
505 rcu_read_unlock();
506 return matching;
509 static void ctnl_timeout_put(struct ctnl_timeout *timeout)
511 atomic_dec(&timeout->refcnt);
512 module_put(THIS_MODULE);
514 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
516 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
517 [IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
518 .attr_count = CTA_TIMEOUT_MAX,
519 .policy = cttimeout_nla_policy },
520 [IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
521 .attr_count = CTA_TIMEOUT_MAX,
522 .policy = cttimeout_nla_policy },
523 [IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
524 .attr_count = CTA_TIMEOUT_MAX,
525 .policy = cttimeout_nla_policy },
526 [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
527 .attr_count = CTA_TIMEOUT_MAX,
528 .policy = cttimeout_nla_policy },
529 [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
530 .attr_count = CTA_TIMEOUT_MAX,
531 .policy = cttimeout_nla_policy },
534 static const struct nfnetlink_subsystem cttimeout_subsys = {
535 .name = "conntrack_timeout",
536 .subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
537 .cb_count = IPCTNL_MSG_TIMEOUT_MAX,
538 .cb = cttimeout_cb,
541 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
543 static int __init cttimeout_init(void)
545 int ret;
547 ret = nfnetlink_subsys_register(&cttimeout_subsys);
548 if (ret < 0) {
549 pr_err("cttimeout_init: cannot register cttimeout with "
550 "nfnetlink.\n");
551 goto err_out;
553 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
554 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
555 RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
556 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
557 return 0;
559 err_out:
560 return ret;
563 static void __exit cttimeout_exit(void)
565 struct ctnl_timeout *cur, *tmp;
567 pr_info("cttimeout: unregistering from nfnetlink.\n");
569 nfnetlink_subsys_unregister(&cttimeout_subsys);
570 list_for_each_entry_safe(cur, tmp, &cttimeout_list, head) {
571 list_del_rcu(&cur->head);
572 /* We are sure that our objects have no clients at this point,
573 * it's safe to release them all without checking refcnt.
575 nf_ct_l4proto_put(cur->l4proto);
576 kfree_rcu(cur, rcu_head);
578 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
579 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
580 RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
581 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
584 module_init(cttimeout_init);
585 module_exit(cttimeout_exit);