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 inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct)
25 /* Previously seen (loopback)? Ignore. */
26 if (skb->nfct != NULL)
29 atomic_inc(&ct->ct_general.use);
30 skb->nfct = &ct->ct_general;
31 skb->nfctinfo = IP_CT_NEW;
36 static unsigned int xt_ct_target_v0(struct sk_buff *skb,
37 const struct xt_action_param *par)
39 const struct xt_ct_target_info *info = par->targinfo;
40 struct nf_conn *ct = info->ct;
42 return xt_ct_target(skb, ct);
45 static unsigned int xt_ct_target_v1(struct sk_buff *skb,
46 const struct xt_action_param *par)
48 const struct xt_ct_target_info_v1 *info = par->targinfo;
49 struct nf_conn *ct = info->ct;
51 return xt_ct_target(skb, ct);
54 static u8 xt_ct_find_proto(const struct xt_tgchk_param *par)
56 if (par->family == NFPROTO_IPV4) {
57 const struct ipt_entry *e = par->entryinfo;
59 if (e->ip.invflags & IPT_INV_PROTO)
62 } else if (par->family == NFPROTO_IPV6) {
63 const struct ip6t_entry *e = par->entryinfo;
65 if (e->ipv6.invflags & IP6T_INV_PROTO)
73 xt_ct_set_helper(struct nf_conn *ct, const char *helper_name,
74 const struct xt_tgchk_param *par)
76 struct nf_conntrack_helper *helper;
77 struct nf_conn_help *help;
80 proto = xt_ct_find_proto(par);
82 pr_info("You must specify a L4 protocol, and not use "
83 "inversions on it.\n");
87 helper = nf_conntrack_helper_try_module_get(helper_name, par->family,
90 pr_info("No such helper \"%s\"\n", helper_name);
94 help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
96 module_put(helper->me);
100 help->helper = helper;
104 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
105 static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout)
107 typeof(nf_ct_timeout_put_hook) timeout_put;
109 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
111 timeout_put(timeout);
116 xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
117 const char *timeout_name)
119 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
120 typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
121 struct ctnl_timeout *timeout;
122 struct nf_conn_timeout *timeout_ext;
123 struct nf_conntrack_l4proto *l4proto;
128 timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook);
129 if (timeout_find_get == NULL) {
131 pr_info("Timeout policy base is empty\n");
135 proto = xt_ct_find_proto(par);
138 pr_info("You must specify a L4 protocol, and not use "
139 "inversions on it.\n");
143 timeout = timeout_find_get(timeout_name);
144 if (timeout == NULL) {
146 pr_info("No such timeout policy \"%s\"\n", timeout_name);
150 if (timeout->l3num != par->family) {
152 pr_info("Timeout policy `%s' can only be used by L3 protocol "
153 "number %d\n", timeout_name, timeout->l3num);
154 goto err_put_timeout;
156 /* Make sure the timeout policy matches any existing protocol tracker,
157 * otherwise default to generic.
159 l4proto = __nf_ct_l4proto_find(par->family, proto);
160 if (timeout->l4proto->l4proto != l4proto->l4proto) {
162 pr_info("Timeout policy `%s' can only be used by L4 protocol "
164 timeout_name, timeout->l4proto->l4proto);
165 goto err_put_timeout;
167 timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
168 if (timeout_ext == NULL)
172 __xt_ct_tg_timeout_put(timeout);
181 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
182 struct xt_ct_target_info_v1 *info)
184 struct nf_conntrack_tuple t;
186 int ret = -EOPNOTSUPP;
188 if (info->flags & XT_CT_NOTRACK) {
189 ct = nf_ct_untracked_get();
190 atomic_inc(&ct->ct_general.use);
194 #ifndef CONFIG_NF_CONNTRACK_ZONES
199 ret = nf_ct_l3proto_try_module_get(par->family);
203 memset(&t, 0, sizeof(t));
204 ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
210 if ((info->ct_events || info->exp_events) &&
211 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
215 if (info->helper[0]) {
216 ret = xt_ct_set_helper(ct, info->helper, par);
221 if (info->timeout[0]) {
222 ret = xt_ct_set_timeout(ct, par, info->timeout);
227 __set_bit(IPS_TEMPLATE_BIT, &ct->status);
228 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
230 /* Overload tuple linked list to put us in template list. */
231 hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
238 nf_conntrack_free(ct);
240 nf_ct_l3proto_module_put(par->family);
245 static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
247 struct xt_ct_target_info *info = par->targinfo;
248 struct xt_ct_target_info_v1 info_v1 = {
249 .flags = info->flags,
251 .ct_events = info->ct_events,
252 .exp_events = info->exp_events,
256 if (info->flags & ~XT_CT_NOTRACK)
259 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
261 ret = xt_ct_tg_check(par, &info_v1);
265 info->ct = info_v1.ct;
270 static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
272 struct xt_ct_target_info_v1 *info = par->targinfo;
274 if (info->flags & ~XT_CT_NOTRACK)
277 return xt_ct_tg_check(par, par->targinfo);
280 static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
282 struct xt_ct_target_info_v1 *info = par->targinfo;
284 if (info->flags & ~XT_CT_MASK)
287 return xt_ct_tg_check(par, par->targinfo);
290 static void xt_ct_destroy_timeout(struct nf_conn *ct)
292 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
293 struct nf_conn_timeout *timeout_ext;
294 typeof(nf_ct_timeout_put_hook) timeout_put;
297 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
300 timeout_ext = nf_ct_timeout_find(ct);
302 timeout_put(timeout_ext->timeout);
308 static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
309 struct xt_ct_target_info_v1 *info)
311 struct nf_conn *ct = info->ct;
312 struct nf_conn_help *help;
314 if (!nf_ct_is_untracked(ct)) {
315 help = nfct_help(ct);
317 module_put(help->helper->me);
319 nf_ct_l3proto_module_put(par->family);
321 xt_ct_destroy_timeout(ct);
326 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
328 struct xt_ct_target_info *info = par->targinfo;
329 struct xt_ct_target_info_v1 info_v1 = {
330 .flags = info->flags,
332 .ct_events = info->ct_events,
333 .exp_events = info->exp_events,
336 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
338 xt_ct_tg_destroy(par, &info_v1);
341 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
343 xt_ct_tg_destroy(par, par->targinfo);
346 static struct xt_target xt_ct_tg_reg[] __read_mostly = {
349 .family = NFPROTO_UNSPEC,
350 .targetsize = sizeof(struct xt_ct_target_info),
351 .checkentry = xt_ct_tg_check_v0,
352 .destroy = xt_ct_tg_destroy_v0,
353 .target = xt_ct_target_v0,
359 .family = NFPROTO_UNSPEC,
361 .targetsize = sizeof(struct xt_ct_target_info_v1),
362 .checkentry = xt_ct_tg_check_v1,
363 .destroy = xt_ct_tg_destroy_v1,
364 .target = xt_ct_target_v1,
370 .family = NFPROTO_UNSPEC,
372 .targetsize = sizeof(struct xt_ct_target_info_v1),
373 .checkentry = xt_ct_tg_check_v2,
374 .destroy = xt_ct_tg_destroy_v1,
375 .target = xt_ct_target_v1,
382 notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
384 /* Previously seen (loopback)? Ignore. */
385 if (skb->nfct != NULL)
388 skb->nfct = &nf_ct_untracked_get()->ct_general;
389 skb->nfctinfo = IP_CT_NEW;
390 nf_conntrack_get(skb->nfct);
395 static int notrack_chk(const struct xt_tgchk_param *par)
397 if (!par->net->xt.notrack_deprecated_warning) {
398 pr_info("netfilter: NOTRACK target is deprecated, "
399 "use CT instead or upgrade iptables\n");
400 par->net->xt.notrack_deprecated_warning = true;
405 static struct xt_target notrack_tg_reg __read_mostly = {
408 .family = NFPROTO_UNSPEC,
409 .checkentry = notrack_chk,
410 .target = notrack_tg,
415 static int __init xt_ct_tg_init(void)
419 ret = xt_register_target(¬rack_tg_reg);
423 ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
425 xt_unregister_target(¬rack_tg_reg);
431 static void __exit xt_ct_tg_exit(void)
433 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
434 xt_unregister_target(¬rack_tg_reg);
437 module_init(xt_ct_tg_init);
438 module_exit(xt_ct_tg_exit);
440 MODULE_LICENSE("GPL");
441 MODULE_DESCRIPTION("Xtables: connection tracking target");
442 MODULE_ALIAS("ipt_CT");
443 MODULE_ALIAS("ip6t_CT");
444 MODULE_ALIAS("ipt_NOTRACK");
445 MODULE_ALIAS("ip6t_NOTRACK");