1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
4 * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
5 */
6
7#include <linux/types.h>
8#include <linux/netfilter.h>
9#include <linux/skbuff.h>
10#include <linux/vmalloc.h>
11#include <linux/stddef.h>
12#include <linux/err.h>
13#include <linux/percpu.h>
14#include <linux/kernel.h>
15#include <linux/netdevice.h>
16#include <linux/slab.h>
17#include <linux/export.h>
18
19#include <net/netfilter/nf_conntrack.h>
20#include <net/netfilter/nf_conntrack_core.h>
21#include <net/netfilter/nf_conntrack_extend.h>
22#include <net/netfilter/nf_conntrack_l4proto.h>
23#include <net/netfilter/nf_conntrack_timeout.h>
24
25const struct nf_ct_timeout_hooks __rcu *nf_ct_timeout_hook __read_mostly;
26EXPORT_SYMBOL_GPL(nf_ct_timeout_hook);
27
28static int untimeout(struct nf_conn *ct, void *timeout)
29{
30 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
31
32 if (timeout_ext) {
33 const struct nf_ct_timeout *t;
34
35 t = rcu_access_pointer(timeout_ext->timeout);
36
37 if (!timeout || t == timeout)
38 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
39 }
40
41 /* We are not intended to delete this conntrack. */
42 return 0;
43}
44
45void nf_ct_untimeout(struct net *net, struct nf_ct_timeout *timeout)
46{
47 struct nf_ct_iter_data iter_data = {
48 .net = net,
49 .data = timeout,
50 };
51
52 nf_ct_iterate_cleanup_net(iter: untimeout, iter_data: &iter_data);
53}
54EXPORT_SYMBOL_GPL(nf_ct_untimeout);
55
56static void __nf_ct_timeout_put(struct nf_ct_timeout *timeout)
57{
58 const struct nf_ct_timeout_hooks *h = rcu_dereference(nf_ct_timeout_hook);
59
60 if (h)
61 h->timeout_put(timeout);
62}
63
64int nf_ct_set_timeout(struct net *net, struct nf_conn *ct,
65 u8 l3num, u8 l4num, const char *timeout_name)
66{
67 const struct nf_ct_timeout_hooks *h;
68 struct nf_ct_timeout *timeout;
69 struct nf_conn_timeout *timeout_ext;
70 const char *errmsg = NULL;
71 int ret = 0;
72
73 rcu_read_lock();
74 h = rcu_dereference(nf_ct_timeout_hook);
75 if (!h) {
76 ret = -ENOENT;
77 errmsg = "Timeout policy base is empty";
78 goto out;
79 }
80
81 timeout = h->timeout_find_get(net, timeout_name);
82 if (!timeout) {
83 ret = -ENOENT;
84 pr_info_ratelimited("No such timeout policy \"%s\"\n",
85 timeout_name);
86 goto out;
87 }
88
89 if (timeout->l3num != l3num) {
90 ret = -EINVAL;
91 pr_info_ratelimited("Timeout policy `%s' can only be used by "
92 "L%d protocol number %d\n",
93 timeout_name, 3, timeout->l3num);
94 goto err_put_timeout;
95 }
96 /* Make sure the timeout policy matches any existing protocol tracker,
97 * otherwise default to generic.
98 */
99 if (timeout->l4proto->l4proto != l4num) {
100 ret = -EINVAL;
101 pr_info_ratelimited("Timeout policy `%s' can only be used by "
102 "L%d protocol number %d\n",
103 timeout_name, 4, timeout->l4proto->l4proto);
104 goto err_put_timeout;
105 }
106 timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
107 if (!timeout_ext) {
108 ret = -ENOMEM;
109 goto err_put_timeout;
110 }
111
112 rcu_read_unlock();
113 return ret;
114
115err_put_timeout:
116 __nf_ct_timeout_put(timeout);
117out:
118 rcu_read_unlock();
119 if (errmsg)
120 pr_info_ratelimited("%s\n", errmsg);
121 return ret;
122}
123EXPORT_SYMBOL_GPL(nf_ct_set_timeout);
124
125void nf_ct_destroy_timeout(struct nf_conn *ct)
126{
127 struct nf_conn_timeout *timeout_ext;
128 const struct nf_ct_timeout_hooks *h;
129
130 rcu_read_lock();
131 h = rcu_dereference(nf_ct_timeout_hook);
132
133 if (h) {
134 timeout_ext = nf_ct_timeout_find(ct);
135 if (timeout_ext) {
136 struct nf_ct_timeout *t;
137
138 t = rcu_dereference(timeout_ext->timeout);
139 if (t)
140 h->timeout_put(t);
141 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
142 }
143 }
144 rcu_read_unlock();
145}
146EXPORT_SYMBOL_GPL(nf_ct_destroy_timeout);
147

source code of linux/net/netfilter/nf_conntrack_timeout.c