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).
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>
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 [CTA_TIMEOUT_L3PROTO
] = { .type
= NLA_U16
},
46 [CTA_TIMEOUT_L4PROTO
] = { .type
= NLA_U8
},
47 [CTA_TIMEOUT_DATA
] = { .type
= NLA_NESTED
},
51 ctnl_timeout_parse_policy(struct ctnl_timeout
*timeout
,
52 struct nf_conntrack_l4proto
*l4proto
,
53 const struct nlattr
*attr
)
57 if (likely(l4proto
->ctnl_timeout
.nlattr_to_obj
)) {
58 struct nlattr
*tb
[l4proto
->ctnl_timeout
.nlattr_max
+1];
60 nla_parse_nested(tb
, l4proto
->ctnl_timeout
.nlattr_max
,
61 attr
, l4proto
->ctnl_timeout
.nla_policy
);
63 ret
= l4proto
->ctnl_timeout
.nlattr_to_obj(tb
, &timeout
->data
);
69 cttimeout_new_timeout(struct sock
*ctnl
, struct sk_buff
*skb
,
70 const struct nlmsghdr
*nlh
,
71 const struct nlattr
* const cda
[])
75 struct nf_conntrack_l4proto
*l4proto
;
76 struct ctnl_timeout
*timeout
, *matching
= NULL
;
80 if (!cda
[CTA_TIMEOUT_NAME
] ||
81 !cda
[CTA_TIMEOUT_L3PROTO
] ||
82 !cda
[CTA_TIMEOUT_L4PROTO
] ||
83 !cda
[CTA_TIMEOUT_DATA
])
86 name
= nla_data(cda
[CTA_TIMEOUT_NAME
]);
87 l3num
= ntohs(nla_get_be16(cda
[CTA_TIMEOUT_L3PROTO
]));
88 l4num
= nla_get_u8(cda
[CTA_TIMEOUT_L4PROTO
]);
90 list_for_each_entry(timeout
, &cttimeout_list
, head
) {
91 if (strncmp(timeout
->name
, name
, CTNL_TIMEOUT_NAME_MAX
) != 0)
94 if (nlh
->nlmsg_flags
& NLM_F_EXCL
)
101 l4proto
= nf_ct_l4proto_find_get(l3num
, l4num
);
103 /* This protocol is not supportted, skip. */
104 if (l4proto
->l4proto
!= l4num
) {
110 if (nlh
->nlmsg_flags
& NLM_F_REPLACE
) {
111 /* You cannot replace one timeout policy by another of
112 * different kind, sorry.
114 if (matching
->l3num
!= l3num
||
115 matching
->l4proto
->l4proto
!= l4num
) {
120 ret
= ctnl_timeout_parse_policy(matching
, l4proto
,
121 cda
[CTA_TIMEOUT_DATA
]);
128 timeout
= kzalloc(sizeof(struct ctnl_timeout
) +
129 l4proto
->ctnl_timeout
.obj_size
, GFP_KERNEL
);
130 if (timeout
== NULL
) {
135 ret
= ctnl_timeout_parse_policy(timeout
, l4proto
,
136 cda
[CTA_TIMEOUT_DATA
]);
140 strcpy(timeout
->name
, nla_data(cda
[CTA_TIMEOUT_NAME
]));
141 timeout
->l3num
= l3num
;
142 timeout
->l4proto
= l4proto
;
143 atomic_set(&timeout
->refcnt
, 1);
144 list_add_tail_rcu(&timeout
->head
, &cttimeout_list
);
150 nf_ct_l4proto_put(l4proto
);
155 ctnl_timeout_fill_info(struct sk_buff
*skb
, u32 pid
, u32 seq
, u32 type
,
156 int event
, struct ctnl_timeout
*timeout
)
158 struct nlmsghdr
*nlh
;
159 struct nfgenmsg
*nfmsg
;
160 unsigned int flags
= pid
? NLM_F_MULTI
: 0;
161 struct nf_conntrack_l4proto
*l4proto
= timeout
->l4proto
;
163 event
|= NFNL_SUBSYS_CTNETLINK_TIMEOUT
<< 8;
164 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*nfmsg
), flags
);
168 nfmsg
= nlmsg_data(nlh
);
169 nfmsg
->nfgen_family
= AF_UNSPEC
;
170 nfmsg
->version
= NFNETLINK_V0
;
173 if (nla_put_string(skb
, CTA_TIMEOUT_NAME
, timeout
->name
) ||
174 nla_put_be16(skb
, CTA_TIMEOUT_L3PROTO
, htons(timeout
->l3num
)) ||
175 nla_put_u8(skb
, CTA_TIMEOUT_L4PROTO
, timeout
->l4proto
->l4proto
) ||
176 nla_put_be32(skb
, CTA_TIMEOUT_USE
,
177 htonl(atomic_read(&timeout
->refcnt
))))
178 goto nla_put_failure
;
180 if (likely(l4proto
->ctnl_timeout
.obj_to_nlattr
)) {
181 struct nlattr
*nest_parms
;
184 nest_parms
= nla_nest_start(skb
,
185 CTA_TIMEOUT_DATA
| NLA_F_NESTED
);
187 goto nla_put_failure
;
189 ret
= l4proto
->ctnl_timeout
.obj_to_nlattr(skb
, &timeout
->data
);
191 goto nla_put_failure
;
193 nla_nest_end(skb
, nest_parms
);
201 nlmsg_cancel(skb
, nlh
);
206 ctnl_timeout_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
208 struct ctnl_timeout
*cur
, *last
;
213 last
= (struct ctnl_timeout
*)cb
->args
[1];
218 list_for_each_entry_rcu(cur
, &cttimeout_list
, head
) {
219 if (last
&& cur
!= last
)
222 if (ctnl_timeout_fill_info(skb
, NETLINK_CB(cb
->skb
).pid
,
224 NFNL_MSG_TYPE(cb
->nlh
->nlmsg_type
),
225 IPCTNL_MSG_TIMEOUT_NEW
, cur
) < 0) {
226 cb
->args
[1] = (unsigned long)cur
;
237 cttimeout_get_timeout(struct sock
*ctnl
, struct sk_buff
*skb
,
238 const struct nlmsghdr
*nlh
,
239 const struct nlattr
* const cda
[])
243 struct ctnl_timeout
*cur
;
245 if (nlh
->nlmsg_flags
& NLM_F_DUMP
) {
246 struct netlink_dump_control c
= {
247 .dump
= ctnl_timeout_dump
,
249 return netlink_dump_start(ctnl
, skb
, nlh
, &c
);
252 if (!cda
[CTA_TIMEOUT_NAME
])
254 name
= nla_data(cda
[CTA_TIMEOUT_NAME
]);
256 list_for_each_entry(cur
, &cttimeout_list
, head
) {
257 struct sk_buff
*skb2
;
259 if (strncmp(cur
->name
, name
, CTNL_TIMEOUT_NAME_MAX
) != 0)
262 skb2
= nlmsg_new(NLMSG_DEFAULT_SIZE
, GFP_KERNEL
);
268 ret
= ctnl_timeout_fill_info(skb2
, NETLINK_CB(skb
).pid
,
270 NFNL_MSG_TYPE(nlh
->nlmsg_type
),
271 IPCTNL_MSG_TIMEOUT_NEW
, cur
);
276 ret
= netlink_unicast(ctnl
, skb2
, NETLINK_CB(skb
).pid
,
281 /* this avoids a loop in nfnetlink. */
282 return ret
== -EAGAIN
? -ENOBUFS
: ret
;
287 /* try to delete object, fail if it is still in use. */
288 static int ctnl_timeout_try_del(struct ctnl_timeout
*timeout
)
292 /* we want to avoid races with nf_ct_timeout_find_get. */
293 if (atomic_dec_and_test(&timeout
->refcnt
)) {
294 /* We are protected by nfnl mutex. */
295 list_del_rcu(&timeout
->head
);
296 nf_ct_l4proto_put(timeout
->l4proto
);
297 kfree_rcu(timeout
, rcu_head
);
299 /* still in use, restore reference counter. */
300 atomic_inc(&timeout
->refcnt
);
307 cttimeout_del_timeout(struct sock
*ctnl
, struct sk_buff
*skb
,
308 const struct nlmsghdr
*nlh
,
309 const struct nlattr
* const cda
[])
312 struct ctnl_timeout
*cur
;
315 if (!cda
[CTA_TIMEOUT_NAME
]) {
316 list_for_each_entry(cur
, &cttimeout_list
, head
)
317 ctnl_timeout_try_del(cur
);
321 name
= nla_data(cda
[CTA_TIMEOUT_NAME
]);
323 list_for_each_entry(cur
, &cttimeout_list
, head
) {
324 if (strncmp(cur
->name
, name
, CTNL_TIMEOUT_NAME_MAX
) != 0)
327 ret
= ctnl_timeout_try_del(cur
);
336 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
337 static struct ctnl_timeout
*ctnl_timeout_find_get(const char *name
)
339 struct ctnl_timeout
*timeout
, *matching
= NULL
;
342 list_for_each_entry_rcu(timeout
, &cttimeout_list
, head
) {
343 if (strncmp(timeout
->name
, name
, CTNL_TIMEOUT_NAME_MAX
) != 0)
346 if (!try_module_get(THIS_MODULE
))
349 if (!atomic_inc_not_zero(&timeout
->refcnt
)) {
350 module_put(THIS_MODULE
);
361 static void ctnl_timeout_put(struct ctnl_timeout
*timeout
)
363 atomic_dec(&timeout
->refcnt
);
364 module_put(THIS_MODULE
);
366 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
368 static const struct nfnl_callback cttimeout_cb
[IPCTNL_MSG_TIMEOUT_MAX
] = {
369 [IPCTNL_MSG_TIMEOUT_NEW
] = { .call
= cttimeout_new_timeout
,
370 .attr_count
= CTA_TIMEOUT_MAX
,
371 .policy
= cttimeout_nla_policy
},
372 [IPCTNL_MSG_TIMEOUT_GET
] = { .call
= cttimeout_get_timeout
,
373 .attr_count
= CTA_TIMEOUT_MAX
,
374 .policy
= cttimeout_nla_policy
},
375 [IPCTNL_MSG_TIMEOUT_DELETE
] = { .call
= cttimeout_del_timeout
,
376 .attr_count
= CTA_TIMEOUT_MAX
,
377 .policy
= cttimeout_nla_policy
},
380 static const struct nfnetlink_subsystem cttimeout_subsys
= {
381 .name
= "conntrack_timeout",
382 .subsys_id
= NFNL_SUBSYS_CTNETLINK_TIMEOUT
,
383 .cb_count
= IPCTNL_MSG_TIMEOUT_MAX
,
387 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT
);
389 static int __init
cttimeout_init(void)
393 ret
= nfnetlink_subsys_register(&cttimeout_subsys
);
395 pr_err("cttimeout_init: cannot register cttimeout with "
399 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
400 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook
, ctnl_timeout_find_get
);
401 RCU_INIT_POINTER(nf_ct_timeout_put_hook
, ctnl_timeout_put
);
402 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
409 static void __exit
cttimeout_exit(void)
411 struct ctnl_timeout
*cur
, *tmp
;
413 pr_info("cttimeout: unregistering from nfnetlink.\n");
415 nfnetlink_subsys_unregister(&cttimeout_subsys
);
416 list_for_each_entry_safe(cur
, tmp
, &cttimeout_list
, head
) {
417 list_del_rcu(&cur
->head
);
418 /* We are sure that our objects have no clients at this point,
419 * it's safe to release them all without checking refcnt.
421 nf_ct_l4proto_put(cur
->l4proto
);
422 kfree_rcu(cur
, rcu_head
);
424 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
425 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook
, NULL
);
426 RCU_INIT_POINTER(nf_ct_timeout_put_hook
, NULL
);
427 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
430 module_init(cttimeout_init
);
431 module_exit(cttimeout_exit
);