2 * Copyright (c) 2010 Patrick McHardy <kaber@trash.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/module.h>
10 #include <linux/gfp.h>
11 #include <linux/skbuff.h>
12 #include <linux/netfilter_ipv4/ip_tables.h>
13 #include <linux/netfilter_ipv6/ip6_tables.h>
14 #include <linux/netfilter/x_tables.h>
15 #include <linux/netfilter/xt_CT.h>
16 #include <net/netfilter/nf_conntrack.h>
17 #include <net/netfilter/nf_conntrack_l4proto.h>
18 #include <net/netfilter/nf_conntrack_helper.h>
19 #include <net/netfilter/nf_conntrack_ecache.h>
20 #include <net/netfilter/nf_conntrack_timeout.h>
21 #include <net/netfilter/nf_conntrack_zones.h>
23 static unsigned int xt_ct_target_v0(struct sk_buff *skb,
24 const struct xt_action_param *par)
26 const struct xt_ct_target_info *info = par->targinfo;
27 struct nf_conn *ct = info->ct;
29 /* Previously seen (loopback)? Ignore. */
30 if (skb->nfct != NULL)
33 atomic_inc(&ct->ct_general.use);
34 skb->nfct = &ct->ct_general;
35 skb->nfctinfo = IP_CT_NEW;
40 static unsigned int xt_ct_target_v1(struct sk_buff *skb,
41 const struct xt_action_param *par)
43 const struct xt_ct_target_info_v1 *info = par->targinfo;
44 struct nf_conn *ct = info->ct;
46 /* Previously seen (loopback)? Ignore. */
47 if (skb->nfct != NULL)
50 atomic_inc(&ct->ct_general.use);
51 skb->nfct = &ct->ct_general;
52 skb->nfctinfo = IP_CT_NEW;
57 static u8 xt_ct_find_proto(const struct xt_tgchk_param *par)
59 if (par->family == NFPROTO_IPV4) {
60 const struct ipt_entry *e = par->entryinfo;
62 if (e->ip.invflags & IPT_INV_PROTO)
65 } else if (par->family == NFPROTO_IPV6) {
66 const struct ip6t_entry *e = par->entryinfo;
68 if (e->ipv6.invflags & IP6T_INV_PROTO)
76 xt_ct_set_helper(struct nf_conn *ct, const char *helper_name,
77 const struct xt_tgchk_param *par)
79 struct nf_conntrack_helper *helper;
80 struct nf_conn_help *help;
83 proto = xt_ct_find_proto(par);
85 pr_info("You must specify a L4 protocol, and not use "
86 "inversions on it.\n");
90 helper = nf_conntrack_helper_try_module_get(helper_name, par->family,
93 pr_info("No such helper \"%s\"\n", helper_name);
97 help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
99 module_put(helper->me);
103 help->helper = helper;
107 static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
109 struct xt_ct_target_info *info = par->targinfo;
110 struct nf_conntrack_tuple t;
114 if (info->flags & ~XT_CT_NOTRACK)
117 if (info->flags & XT_CT_NOTRACK) {
118 ct = nf_ct_untracked_get();
119 atomic_inc(&ct->ct_general.use);
123 #ifndef CONFIG_NF_CONNTRACK_ZONES
128 ret = nf_ct_l3proto_try_module_get(par->family);
132 memset(&t, 0, sizeof(t));
133 ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
139 if ((info->ct_events || info->exp_events) &&
140 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
144 if (info->helper[0]) {
145 ret = xt_ct_set_helper(ct, info->helper, par);
150 __set_bit(IPS_TEMPLATE_BIT, &ct->status);
151 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
157 nf_conntrack_free(ct);
159 nf_ct_l3proto_module_put(par->family);
164 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
165 static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout)
167 typeof(nf_ct_timeout_put_hook) timeout_put;
169 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
171 timeout_put(timeout);
176 xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
177 const char *timeout_name)
179 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
180 typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
181 struct ctnl_timeout *timeout;
182 struct nf_conn_timeout *timeout_ext;
183 const struct ipt_entry *e = par->entryinfo;
184 struct nf_conntrack_l4proto *l4proto;
188 timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook);
189 if (timeout_find_get == NULL) {
191 pr_info("Timeout policy base is empty\n");
195 if (e->ip.invflags & IPT_INV_PROTO) {
197 pr_info("You cannot use inversion on L4 protocol\n");
201 timeout = timeout_find_get(timeout_name);
202 if (timeout == NULL) {
204 pr_info("No such timeout policy \"%s\"\n", timeout_name);
208 if (timeout->l3num != par->family) {
210 pr_info("Timeout policy `%s' can only be used by L3 protocol "
211 "number %d\n", timeout_name, timeout->l3num);
212 goto err_put_timeout;
214 /* Make sure the timeout policy matches any existing protocol tracker,
215 * otherwise default to generic.
217 l4proto = __nf_ct_l4proto_find(par->family, e->ip.proto);
218 if (timeout->l4proto->l4proto != l4proto->l4proto) {
220 pr_info("Timeout policy `%s' can only be used by L4 protocol "
222 timeout_name, timeout->l4proto->l4proto);
223 goto err_put_timeout;
225 timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
226 if (timeout_ext == NULL)
230 __xt_ct_tg_timeout_put(timeout);
239 static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
241 struct xt_ct_target_info_v1 *info = par->targinfo;
242 struct nf_conntrack_tuple t;
246 if (info->flags & ~XT_CT_NOTRACK)
249 if (info->flags & XT_CT_NOTRACK) {
250 ct = nf_ct_untracked_get();
251 atomic_inc(&ct->ct_general.use);
255 #ifndef CONFIG_NF_CONNTRACK_ZONES
260 ret = nf_ct_l3proto_try_module_get(par->family);
264 memset(&t, 0, sizeof(t));
265 ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
271 if ((info->ct_events || info->exp_events) &&
272 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
276 if (info->helper[0]) {
277 ret = xt_ct_set_helper(ct, info->helper, par);
282 if (info->timeout[0]) {
283 ret = xt_ct_set_timeout(ct, par, info->timeout);
288 __set_bit(IPS_TEMPLATE_BIT, &ct->status);
289 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
295 nf_conntrack_free(ct);
297 nf_ct_l3proto_module_put(par->family);
302 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
304 struct xt_ct_target_info *info = par->targinfo;
305 struct nf_conn *ct = info->ct;
306 struct nf_conn_help *help;
308 if (!nf_ct_is_untracked(ct)) {
309 help = nfct_help(ct);
311 module_put(help->helper->me);
313 nf_ct_l3proto_module_put(par->family);
318 static void xt_ct_destroy_timeout(struct nf_conn *ct)
320 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
321 struct nf_conn_timeout *timeout_ext;
322 typeof(nf_ct_timeout_put_hook) timeout_put;
325 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
328 timeout_ext = nf_ct_timeout_find(ct);
330 timeout_put(timeout_ext->timeout);
336 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
338 struct xt_ct_target_info_v1 *info = par->targinfo;
339 struct nf_conn *ct = info->ct;
340 struct nf_conn_help *help;
342 if (!nf_ct_is_untracked(ct)) {
343 help = nfct_help(ct);
345 module_put(help->helper->me);
347 nf_ct_l3proto_module_put(par->family);
349 xt_ct_destroy_timeout(ct);
354 static struct xt_target xt_ct_tg_reg[] __read_mostly = {
357 .family = NFPROTO_UNSPEC,
358 .targetsize = sizeof(struct xt_ct_target_info),
359 .checkentry = xt_ct_tg_check_v0,
360 .destroy = xt_ct_tg_destroy_v0,
361 .target = xt_ct_target_v0,
367 .family = NFPROTO_UNSPEC,
369 .targetsize = sizeof(struct xt_ct_target_info_v1),
370 .checkentry = xt_ct_tg_check_v1,
371 .destroy = xt_ct_tg_destroy_v1,
372 .target = xt_ct_target_v1,
378 static int __init xt_ct_tg_init(void)
380 return xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
383 static void __exit xt_ct_tg_exit(void)
385 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
388 module_init(xt_ct_tg_init);
389 module_exit(xt_ct_tg_exit);
391 MODULE_LICENSE("GPL");
392 MODULE_DESCRIPTION("Xtables: connection tracking target");
393 MODULE_ALIAS("ipt_CT");
394 MODULE_ALIAS("ip6t_CT");