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(untimeout, &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