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 /* special case the untracked ct : we want the percpu object */
31 ct = nf_ct_untracked_get();
32 atomic_inc(&ct->ct_general.use);
33 skb->nfct = &ct->ct_general;
34 skb->nfctinfo = IP_CT_NEW;
39 static unsigned int xt_ct_target_v0(struct sk_buff *skb,
40 const struct xt_action_param *par)
42 const struct xt_ct_target_info *info = par->targinfo;
43 struct nf_conn *ct = info->ct;
45 return xt_ct_target(skb, ct);
48 static unsigned int xt_ct_target_v1(struct sk_buff *skb,
49 const struct xt_action_param *par)
51 const struct xt_ct_target_info_v1 *info = par->targinfo;
52 struct nf_conn *ct = info->ct;
54 return xt_ct_target(skb, ct);
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 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
108 static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout)
110 typeof(nf_ct_timeout_put_hook) timeout_put;
112 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
114 timeout_put(timeout);
119 xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
120 const char *timeout_name)
122 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
123 typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
124 struct ctnl_timeout *timeout;
125 struct nf_conn_timeout *timeout_ext;
126 struct nf_conntrack_l4proto *l4proto;
131 timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook);
132 if (timeout_find_get == NULL) {
134 pr_info("Timeout policy base is empty\n");
138 proto = xt_ct_find_proto(par);
141 pr_info("You must specify a L4 protocol, and not use "
142 "inversions on it.\n");
146 timeout = timeout_find_get(timeout_name);
147 if (timeout == NULL) {
149 pr_info("No such timeout policy \"%s\"\n", timeout_name);
153 if (timeout->l3num != par->family) {
155 pr_info("Timeout policy `%s' can only be used by L3 protocol "
156 "number %d\n", timeout_name, timeout->l3num);
157 goto err_put_timeout;
159 /* Make sure the timeout policy matches any existing protocol tracker,
160 * otherwise default to generic.
162 l4proto = __nf_ct_l4proto_find(par->family, proto);
163 if (timeout->l4proto->l4proto != l4proto->l4proto) {
165 pr_info("Timeout policy `%s' can only be used by L4 protocol "
167 timeout_name, timeout->l4proto->l4proto);
168 goto err_put_timeout;
170 timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
171 if (timeout_ext == NULL)
175 __xt_ct_tg_timeout_put(timeout);
184 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
185 struct xt_ct_target_info_v1 *info)
188 int ret = -EOPNOTSUPP;
190 if (info->flags & XT_CT_NOTRACK) {
195 #ifndef CONFIG_NF_CONNTRACK_ZONES
200 ret = nf_ct_l3proto_try_module_get(par->family);
204 ct = nf_ct_tmpl_alloc(par->net, info->zone, GFP_KERNEL);
210 if ((info->ct_events || info->exp_events) &&
211 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
217 if (info->helper[0]) {
218 ret = xt_ct_set_helper(ct, info->helper, par);
223 if (info->timeout[0]) {
224 ret = xt_ct_set_timeout(ct, par, info->timeout);
228 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
229 nf_conntrack_get(&ct->ct_general);
235 nf_conntrack_free(ct);
237 nf_ct_l3proto_module_put(par->family);
242 static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
244 struct xt_ct_target_info *info = par->targinfo;
245 struct xt_ct_target_info_v1 info_v1 = {
246 .flags = info->flags,
248 .ct_events = info->ct_events,
249 .exp_events = info->exp_events,
253 if (info->flags & ~XT_CT_NOTRACK)
256 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
258 ret = xt_ct_tg_check(par, &info_v1);
262 info->ct = info_v1.ct;
267 static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
269 struct xt_ct_target_info_v1 *info = par->targinfo;
271 if (info->flags & ~XT_CT_NOTRACK)
274 return xt_ct_tg_check(par, par->targinfo);
277 static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
279 struct xt_ct_target_info_v1 *info = par->targinfo;
281 if (info->flags & ~XT_CT_MASK)
284 return xt_ct_tg_check(par, par->targinfo);
287 static void xt_ct_destroy_timeout(struct nf_conn *ct)
289 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
290 struct nf_conn_timeout *timeout_ext;
291 typeof(nf_ct_timeout_put_hook) timeout_put;
294 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
297 timeout_ext = nf_ct_timeout_find(ct);
299 timeout_put(timeout_ext->timeout);
305 static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
306 struct xt_ct_target_info_v1 *info)
308 struct nf_conn *ct = info->ct;
309 struct nf_conn_help *help;
311 if (ct && !nf_ct_is_untracked(ct)) {
312 help = nfct_help(ct);
314 module_put(help->helper->me);
316 nf_ct_l3proto_module_put(par->family);
318 xt_ct_destroy_timeout(ct);
323 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
325 struct xt_ct_target_info *info = par->targinfo;
326 struct xt_ct_target_info_v1 info_v1 = {
327 .flags = info->flags,
329 .ct_events = info->ct_events,
330 .exp_events = info->exp_events,
333 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
335 xt_ct_tg_destroy(par, &info_v1);
338 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
340 xt_ct_tg_destroy(par, par->targinfo);
343 static struct xt_target xt_ct_tg_reg[] __read_mostly = {
346 .family = NFPROTO_UNSPEC,
347 .targetsize = sizeof(struct xt_ct_target_info),
348 .checkentry = xt_ct_tg_check_v0,
349 .destroy = xt_ct_tg_destroy_v0,
350 .target = xt_ct_target_v0,
356 .family = NFPROTO_UNSPEC,
358 .targetsize = sizeof(struct xt_ct_target_info_v1),
359 .checkentry = xt_ct_tg_check_v1,
360 .destroy = xt_ct_tg_destroy_v1,
361 .target = xt_ct_target_v1,
367 .family = NFPROTO_UNSPEC,
369 .targetsize = sizeof(struct xt_ct_target_info_v1),
370 .checkentry = xt_ct_tg_check_v2,
371 .destroy = xt_ct_tg_destroy_v1,
372 .target = xt_ct_target_v1,
379 notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
381 /* Previously seen (loopback)? Ignore. */
382 if (skb->nfct != NULL)
385 skb->nfct = &nf_ct_untracked_get()->ct_general;
386 skb->nfctinfo = IP_CT_NEW;
387 nf_conntrack_get(skb->nfct);
392 static int notrack_chk(const struct xt_tgchk_param *par)
394 if (!par->net->xt.notrack_deprecated_warning) {
395 pr_info("netfilter: NOTRACK target is deprecated, "
396 "use CT instead or upgrade iptables\n");
397 par->net->xt.notrack_deprecated_warning = true;
402 static struct xt_target notrack_tg_reg __read_mostly = {
405 .family = NFPROTO_UNSPEC,
406 .checkentry = notrack_chk,
407 .target = notrack_tg,
412 static int __init xt_ct_tg_init(void)
416 ret = xt_register_target(¬rack_tg_reg);
420 ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
422 xt_unregister_target(¬rack_tg_reg);
428 static void __exit xt_ct_tg_exit(void)
430 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
431 xt_unregister_target(¬rack_tg_reg);
434 module_init(xt_ct_tg_init);
435 module_exit(xt_ct_tg_exit);
437 MODULE_LICENSE("GPL");
438 MODULE_DESCRIPTION("Xtables: connection tracking target");
439 MODULE_ALIAS("ipt_CT");
440 MODULE_ALIAS("ip6t_CT");
441 MODULE_ALIAS("ipt_NOTRACK");
442 MODULE_ALIAS("ip6t_NOTRACK");