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 .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
},
52 ctnl_timeout_parse_policy(struct ctnl_timeout
*timeout
,
53 struct nf_conntrack_l4proto
*l4proto
,
55 const struct nlattr
*attr
)
59 if (likely(l4proto
->ctnl_timeout
.nlattr_to_obj
)) {
60 struct nlattr
*tb
[l4proto
->ctnl_timeout
.nlattr_max
+1];
62 nla_parse_nested(tb
, l4proto
->ctnl_timeout
.nlattr_max
,
63 attr
, l4proto
->ctnl_timeout
.nla_policy
);
65 ret
= l4proto
->ctnl_timeout
.nlattr_to_obj(tb
, net
,
72 cttimeout_new_timeout(struct sock
*ctnl
, struct sk_buff
*skb
,
73 const struct nlmsghdr
*nlh
,
74 const struct nlattr
* const cda
[])
78 struct nf_conntrack_l4proto
*l4proto
;
79 struct ctnl_timeout
*timeout
, *matching
= NULL
;
80 struct net
*net
= sock_net(skb
->sk
);
84 if (!cda
[CTA_TIMEOUT_NAME
] ||
85 !cda
[CTA_TIMEOUT_L3PROTO
] ||
86 !cda
[CTA_TIMEOUT_L4PROTO
] ||
87 !cda
[CTA_TIMEOUT_DATA
])
90 name
= nla_data(cda
[CTA_TIMEOUT_NAME
]);
91 l3num
= ntohs(nla_get_be16(cda
[CTA_TIMEOUT_L3PROTO
]));
92 l4num
= nla_get_u8(cda
[CTA_TIMEOUT_L4PROTO
]);
94 list_for_each_entry(timeout
, &cttimeout_list
, head
) {
95 if (strncmp(timeout
->name
, name
, CTNL_TIMEOUT_NAME_MAX
) != 0)
98 if (nlh
->nlmsg_flags
& NLM_F_EXCL
)
105 l4proto
= nf_ct_l4proto_find_get(l3num
, l4num
);
107 /* This protocol is not supportted, skip. */
108 if (l4proto
->l4proto
!= l4num
) {
114 if (nlh
->nlmsg_flags
& NLM_F_REPLACE
) {
115 /* You cannot replace one timeout policy by another of
116 * different kind, sorry.
118 if (matching
->l3num
!= l3num
||
119 matching
->l4proto
->l4proto
!= l4num
) {
124 ret
= ctnl_timeout_parse_policy(matching
, l4proto
, net
,
125 cda
[CTA_TIMEOUT_DATA
]);
132 timeout
= kzalloc(sizeof(struct ctnl_timeout
) +
133 l4proto
->ctnl_timeout
.obj_size
, GFP_KERNEL
);
134 if (timeout
== NULL
) {
139 ret
= ctnl_timeout_parse_policy(timeout
, l4proto
, net
,
140 cda
[CTA_TIMEOUT_DATA
]);
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
);
154 nf_ct_l4proto_put(l4proto
);
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
);
172 nfmsg
= nlmsg_data(nlh
);
173 nfmsg
->nfgen_family
= AF_UNSPEC
;
174 nfmsg
->version
= NFNETLINK_V0
;
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
;
188 nest_parms
= nla_nest_start(skb
,
189 CTA_TIMEOUT_DATA
| NLA_F_NESTED
);
191 goto nla_put_failure
;
193 ret
= l4proto
->ctnl_timeout
.obj_to_nlattr(skb
, &timeout
->data
);
195 goto nla_put_failure
;
197 nla_nest_end(skb
, nest_parms
);
205 nlmsg_cancel(skb
, nlh
);
210 ctnl_timeout_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
212 struct ctnl_timeout
*cur
, *last
;
217 last
= (struct ctnl_timeout
*)cb
->args
[1];
222 list_for_each_entry_rcu(cur
, &cttimeout_list
, head
) {
229 if (ctnl_timeout_fill_info(skb
, NETLINK_CB(cb
->skb
).portid
,
231 NFNL_MSG_TYPE(cb
->nlh
->nlmsg_type
),
232 IPCTNL_MSG_TIMEOUT_NEW
, cur
) < 0) {
233 cb
->args
[1] = (unsigned long)cur
;
244 cttimeout_get_timeout(struct sock
*ctnl
, struct sk_buff
*skb
,
245 const struct nlmsghdr
*nlh
,
246 const struct nlattr
* const cda
[])
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
])
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)
269 skb2
= nlmsg_new(NLMSG_DEFAULT_SIZE
, GFP_KERNEL
);
275 ret
= ctnl_timeout_fill_info(skb2
, NETLINK_CB(skb
).portid
,
277 NFNL_MSG_TYPE(nlh
->nlmsg_type
),
278 IPCTNL_MSG_TIMEOUT_NEW
, cur
);
283 ret
= netlink_unicast(ctnl
, skb2
, NETLINK_CB(skb
).portid
,
288 /* this avoids a loop in nfnetlink. */
289 return ret
== -EAGAIN
? -ENOBUFS
: ret
;
294 /* try to delete object, fail if it is still in use. */
295 static int ctnl_timeout_try_del(struct ctnl_timeout
*timeout
)
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
);
306 /* still in use, restore reference counter. */
307 atomic_inc(&timeout
->refcnt
);
314 cttimeout_del_timeout(struct sock
*ctnl
, struct sk_buff
*skb
,
315 const struct nlmsghdr
*nlh
,
316 const struct nlattr
* const cda
[])
319 struct ctnl_timeout
*cur
;
322 if (!cda
[CTA_TIMEOUT_NAME
]) {
323 list_for_each_entry(cur
, &cttimeout_list
, head
)
324 ctnl_timeout_try_del(cur
);
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)
334 ret
= ctnl_timeout_try_del(cur
);
343 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
344 static struct ctnl_timeout
*ctnl_timeout_find_get(const char *name
)
346 struct ctnl_timeout
*timeout
, *matching
= NULL
;
349 list_for_each_entry_rcu(timeout
, &cttimeout_list
, head
) {
350 if (strncmp(timeout
->name
, name
, CTNL_TIMEOUT_NAME_MAX
) != 0)
353 if (!try_module_get(THIS_MODULE
))
356 if (!atomic_inc_not_zero(&timeout
->refcnt
)) {
357 module_put(THIS_MODULE
);
368 static void ctnl_timeout_put(struct ctnl_timeout
*timeout
)
370 atomic_dec(&timeout
->refcnt
);
371 module_put(THIS_MODULE
);
373 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
375 static const struct nfnl_callback cttimeout_cb
[IPCTNL_MSG_TIMEOUT_MAX
] = {
376 [IPCTNL_MSG_TIMEOUT_NEW
] = { .call
= cttimeout_new_timeout
,
377 .attr_count
= CTA_TIMEOUT_MAX
,
378 .policy
= cttimeout_nla_policy
},
379 [IPCTNL_MSG_TIMEOUT_GET
] = { .call
= cttimeout_get_timeout
,
380 .attr_count
= CTA_TIMEOUT_MAX
,
381 .policy
= cttimeout_nla_policy
},
382 [IPCTNL_MSG_TIMEOUT_DELETE
] = { .call
= cttimeout_del_timeout
,
383 .attr_count
= CTA_TIMEOUT_MAX
,
384 .policy
= cttimeout_nla_policy
},
387 static const struct nfnetlink_subsystem cttimeout_subsys
= {
388 .name
= "conntrack_timeout",
389 .subsys_id
= NFNL_SUBSYS_CTNETLINK_TIMEOUT
,
390 .cb_count
= IPCTNL_MSG_TIMEOUT_MAX
,
394 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT
);
396 static int __init
cttimeout_init(void)
400 ret
= nfnetlink_subsys_register(&cttimeout_subsys
);
402 pr_err("cttimeout_init: cannot register cttimeout with "
406 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
407 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook
, ctnl_timeout_find_get
);
408 RCU_INIT_POINTER(nf_ct_timeout_put_hook
, ctnl_timeout_put
);
409 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
416 static void __exit
cttimeout_exit(void)
418 struct ctnl_timeout
*cur
, *tmp
;
420 pr_info("cttimeout: unregistering from nfnetlink.\n");
422 nfnetlink_subsys_unregister(&cttimeout_subsys
);
423 list_for_each_entry_safe(cur
, tmp
, &cttimeout_list
, head
) {
424 list_del_rcu(&cur
->head
);
425 /* We are sure that our objects have no clients at this point,
426 * it's safe to release them all without checking refcnt.
428 nf_ct_l4proto_put(cur
->l4proto
);
429 kfree_rcu(cur
, rcu_head
);
431 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
432 RCU_INIT_POINTER(nf_ct_timeout_find_get_hook
, NULL
);
433 RCU_INIT_POINTER(nf_ct_timeout_put_hook
, NULL
);
435 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
438 module_init(cttimeout_init
);
439 module_exit(cttimeout_exit
);