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. */
30 atomic_inc(&ct->ct_general.use);
31 nf_ct_set(skb, ct, IP_CT_NEW);
33 nf_ct_set(skb, ct, IP_CT_UNTRACKED);
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_ratelimited("You must specify a L4 protocol and not use inversions on it\n");
89 helper = nf_conntrack_helper_try_module_get(helper_name, par->family,
92 pr_info_ratelimited("No such helper \"%s\"\n", helper_name);
96 help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
98 nf_conntrack_helper_put(helper);
102 help->helper = helper;
106 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
107 static void __xt_ct_tg_timeout_put(struct ctnl_timeout *timeout)
109 typeof(nf_ct_timeout_put_hook) timeout_put;
111 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
113 timeout_put(timeout);
118 xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
119 const char *timeout_name)
121 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
122 typeof(nf_ct_timeout_find_get_hook) timeout_find_get;
123 const struct nf_conntrack_l4proto *l4proto;
124 struct ctnl_timeout *timeout;
125 struct nf_conn_timeout *timeout_ext;
126 const char *errmsg = NULL;
131 timeout_find_get = rcu_dereference(nf_ct_timeout_find_get_hook);
132 if (timeout_find_get == NULL) {
134 errmsg = "Timeout policy base is empty";
138 proto = xt_ct_find_proto(par);
141 errmsg = "You must specify a L4 protocol and not use inversions on it";
145 timeout = timeout_find_get(par->net, timeout_name);
146 if (timeout == NULL) {
148 pr_info_ratelimited("No such timeout policy \"%s\"\n",
153 if (timeout->l3num != par->family) {
155 pr_info_ratelimited("Timeout policy `%s' can only be used by L%d protocol number %d\n",
156 timeout_name, 3, 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_ratelimited("Timeout policy `%s' can only be used by L%d protocol number %d\n",
166 timeout_name, 4, timeout->l4proto->l4proto);
167 goto err_put_timeout;
169 timeout_ext = nf_ct_timeout_ext_add(ct, timeout, GFP_ATOMIC);
172 goto err_put_timeout;
179 __xt_ct_tg_timeout_put(timeout);
183 pr_info_ratelimited("%s\n", errmsg);
190 static u16 xt_ct_flags_to_dir(const struct xt_ct_target_info_v1 *info)
192 switch (info->flags & (XT_CT_ZONE_DIR_ORIG |
193 XT_CT_ZONE_DIR_REPL)) {
194 case XT_CT_ZONE_DIR_ORIG:
195 return NF_CT_ZONE_DIR_ORIG;
196 case XT_CT_ZONE_DIR_REPL:
197 return NF_CT_ZONE_DIR_REPL;
199 return NF_CT_DEFAULT_ZONE_DIR;
203 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
204 struct xt_ct_target_info_v1 *info)
206 struct nf_conntrack_zone zone;
207 struct nf_conn_help *help;
209 int ret = -EOPNOTSUPP;
211 if (info->flags & XT_CT_NOTRACK) {
216 #ifndef CONFIG_NF_CONNTRACK_ZONES
217 if (info->zone || info->flags & (XT_CT_ZONE_DIR_ORIG |
218 XT_CT_ZONE_DIR_REPL |
223 ret = nf_ct_netns_get(par->net, par->family);
227 memset(&zone, 0, sizeof(zone));
228 zone.id = info->zone;
229 zone.dir = xt_ct_flags_to_dir(info);
230 if (info->flags & XT_CT_ZONE_MARK)
231 zone.flags |= NF_CT_FLAG_MARK;
233 ct = nf_ct_tmpl_alloc(par->net, &zone, GFP_KERNEL);
240 if ((info->ct_events || info->exp_events) &&
241 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
247 if (info->helper[0]) {
248 ret = xt_ct_set_helper(ct, info->helper, par);
253 if (info->timeout[0]) {
254 ret = xt_ct_set_timeout(ct, par, info->timeout);
258 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
259 nf_conntrack_get(&ct->ct_general);
265 help = nfct_help(ct);
267 nf_conntrack_helper_put(help->helper);
271 nf_ct_netns_put(par->net, par->family);
276 static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
278 struct xt_ct_target_info *info = par->targinfo;
279 struct xt_ct_target_info_v1 info_v1 = {
280 .flags = info->flags,
282 .ct_events = info->ct_events,
283 .exp_events = info->exp_events,
287 if (info->flags & ~XT_CT_NOTRACK)
290 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
292 ret = xt_ct_tg_check(par, &info_v1);
296 info->ct = info_v1.ct;
301 static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
303 struct xt_ct_target_info_v1 *info = par->targinfo;
305 if (info->flags & ~XT_CT_NOTRACK)
308 return xt_ct_tg_check(par, par->targinfo);
311 static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
313 struct xt_ct_target_info_v1 *info = par->targinfo;
315 if (info->flags & ~XT_CT_MASK)
318 return xt_ct_tg_check(par, par->targinfo);
321 static void xt_ct_destroy_timeout(struct nf_conn *ct)
323 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
324 struct nf_conn_timeout *timeout_ext;
325 typeof(nf_ct_timeout_put_hook) timeout_put;
328 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
331 timeout_ext = nf_ct_timeout_find(ct);
333 timeout_put(timeout_ext->timeout);
334 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
341 static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
342 struct xt_ct_target_info_v1 *info)
344 struct nf_conn *ct = info->ct;
345 struct nf_conn_help *help;
348 help = nfct_help(ct);
350 nf_conntrack_helper_put(help->helper);
352 nf_ct_netns_put(par->net, par->family);
354 xt_ct_destroy_timeout(ct);
359 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
361 struct xt_ct_target_info *info = par->targinfo;
362 struct xt_ct_target_info_v1 info_v1 = {
363 .flags = info->flags,
365 .ct_events = info->ct_events,
366 .exp_events = info->exp_events,
369 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
371 xt_ct_tg_destroy(par, &info_v1);
374 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
376 xt_ct_tg_destroy(par, par->targinfo);
379 static struct xt_target xt_ct_tg_reg[] __read_mostly = {
382 .family = NFPROTO_UNSPEC,
383 .targetsize = sizeof(struct xt_ct_target_info),
384 .usersize = offsetof(struct xt_ct_target_info, ct),
385 .checkentry = xt_ct_tg_check_v0,
386 .destroy = xt_ct_tg_destroy_v0,
387 .target = xt_ct_target_v0,
393 .family = NFPROTO_UNSPEC,
395 .targetsize = sizeof(struct xt_ct_target_info_v1),
396 .usersize = offsetof(struct xt_ct_target_info, ct),
397 .checkentry = xt_ct_tg_check_v1,
398 .destroy = xt_ct_tg_destroy_v1,
399 .target = xt_ct_target_v1,
405 .family = NFPROTO_UNSPEC,
407 .targetsize = sizeof(struct xt_ct_target_info_v1),
408 .usersize = offsetof(struct xt_ct_target_info, ct),
409 .checkentry = xt_ct_tg_check_v2,
410 .destroy = xt_ct_tg_destroy_v1,
411 .target = xt_ct_target_v1,
418 notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
420 /* Previously seen (loopback)? Ignore. */
424 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
429 static int notrack_chk(const struct xt_tgchk_param *par)
431 if (!par->net->xt.notrack_deprecated_warning) {
432 pr_info("netfilter: NOTRACK target is deprecated, "
433 "use CT instead or upgrade iptables\n");
434 par->net->xt.notrack_deprecated_warning = true;
439 static struct xt_target notrack_tg_reg __read_mostly = {
442 .family = NFPROTO_UNSPEC,
443 .checkentry = notrack_chk,
444 .target = notrack_tg,
449 static int __init xt_ct_tg_init(void)
453 ret = xt_register_target(¬rack_tg_reg);
457 ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
459 xt_unregister_target(¬rack_tg_reg);
465 static void __exit xt_ct_tg_exit(void)
467 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
468 xt_unregister_target(¬rack_tg_reg);
471 module_init(xt_ct_tg_init);
472 module_exit(xt_ct_tg_exit);
474 MODULE_LICENSE("GPL");
475 MODULE_DESCRIPTION("Xtables: connection tracking target");
476 MODULE_ALIAS("ipt_CT");
477 MODULE_ALIAS("ip6t_CT");
478 MODULE_ALIAS("ipt_NOTRACK");
479 MODULE_ALIAS("ip6t_NOTRACK");