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
25 struct nf_ct_timeout *
26 (*nf_ct_timeout_find_get_hook)(struct net *net, const char *name) __read_mostly;
27 EXPORT_SYMBOL_GPL(nf_ct_timeout_find_get_hook);
28
29 void (*nf_ct_timeout_put_hook)(struct nf_ct_timeout *timeout) __read_mostly;
30 EXPORT_SYMBOL_GPL(nf_ct_timeout_put_hook);
31
untimeout(struct nf_conn * ct,void * timeout)32 static int untimeout(struct nf_conn *ct, void *timeout)
33 {
34 struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
35
36 if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
37 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
38
39 /* We are not intended to delete this conntrack. */
40 return 0;
41 }
42
nf_ct_untimeout(struct net * net,struct nf_ct_timeout * timeout)43 void nf_ct_untimeout(struct net *net, struct nf_ct_timeout *timeout)
44 {
45 nf_ct_iterate_cleanup_net(net, untimeout, timeout, 0, 0);
46 }
47 EXPORT_SYMBOL_GPL(nf_ct_untimeout);
48
__nf_ct_timeout_put(struct nf_ct_timeout * timeout)49 static void __nf_ct_timeout_put(struct nf_ct_timeout *timeout)
50 {
51 typeof(nf_ct_timeout_put_hook) timeout_put;
52
53 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
54 if (timeout_put)
55 timeout_put(timeout);
56 }
57
nf_ct_set_timeout(struct net * net,struct nf_conn * ct,u8 l3num,u8 l4num,const char * timeout_name)58 int nf_ct_set_timeout(struct net *net, struct nf_conn *ct,
59 u8 l3num, u8 l4num, const char *timeout_name)
60 {
61 typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
62 struct nf_ct_timeout *timeout;
63 struct nf_conn_timeout *timeout_ext;
64 const char *errmsg = NULL;
65 int ret = 0;
66
67 rcu_read_lock();
68 timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook);
69 if (!timeout_find_get) {
70 ret = -ENOENT;
71 errmsg = "Timeout policy base is empty";
72 goto out;
73 }
74
75 timeout = timeout_find_get(net, timeout_name);
76 if (!timeout) {
77 ret = -ENOENT;
78 pr_info_ratelimited("No such timeout policy \"%s\"\n",
79 timeout_name);
80 goto out;
81 }
82
83 if (timeout->l3num != l3num) {
84 ret = -EINVAL;
85 pr_info_ratelimited("Timeout policy `%s' can only be used by "
86 "L%d protocol number %d\n",
87 timeout_name, 3, timeout->l3num);
88 goto err_put_timeout;
89 }
90 /* Make sure the timeout policy matches any existing protocol tracker,
91 * otherwise default to generic.
92 */
93 if (timeout->l4proto->l4proto != l4num) {
94 ret = -EINVAL;
95 pr_info_ratelimited("Timeout policy `%s' can only be used by "
96 "L%d protocol number %d\n",
97 timeout_name, 4, timeout->l4proto->l4proto);
98 goto err_put_timeout;
99 }
100 timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
101 if (!timeout_ext) {
102 ret = -ENOMEM;
103 goto err_put_timeout;
104 }
105
106 rcu_read_unlock();
107 return ret;
108
109 err_put_timeout:
110 __nf_ct_timeout_put(timeout);
111 out:
112 rcu_read_unlock();
113 if (errmsg)
114 pr_info_ratelimited("%s\n", errmsg);
115 return ret;
116 }
117 EXPORT_SYMBOL_GPL(nf_ct_set_timeout);
118
nf_ct_destroy_timeout(struct nf_conn * ct)119 void nf_ct_destroy_timeout(struct nf_conn *ct)
120 {
121 struct nf_conn_timeout *timeout_ext;
122 typeof(nf_ct_timeout_put_hook) timeout_put;
123
124 rcu_read_lock();
125 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
126
127 if (timeout_put) {
128 timeout_ext = nf_ct_timeout_find(ct);
129 if (timeout_ext) {
130 timeout_put(timeout_ext->timeout);
131 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
132 }
133 }
134 rcu_read_unlock();
135 }
136 EXPORT_SYMBOL_GPL(nf_ct_destroy_timeout);
137
138 static const struct nf_ct_ext_type timeout_extend = {
139 .len = sizeof(struct nf_conn_timeout),
140 .align = __alignof__(struct nf_conn_timeout),
141 .id = NF_CT_EXT_TIMEOUT,
142 };
143
nf_conntrack_timeout_init(void)144 int nf_conntrack_timeout_init(void)
145 {
146 int ret = nf_ct_extend_register(&timeout_extend);
147 if (ret < 0)
148 pr_err("nf_ct_timeout: Unable to register timeout extension.\n");
149 return ret;
150 }
151
nf_conntrack_timeout_fini(void)152 void nf_conntrack_timeout_fini(void)
153 {
154 nf_ct_extend_unregister(&timeout_extend);
155 }
156