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 u16 xt_ct_flags_to_dir(const struct xt_ct_target_info_v1 *info)
186 switch (info->flags & (XT_CT_ZONE_DIR_ORIG |
187 XT_CT_ZONE_DIR_REPL)) {
188 case XT_CT_ZONE_DIR_ORIG:
189 return NF_CT_ZONE_DIR_ORIG;
190 case XT_CT_ZONE_DIR_REPL:
191 return NF_CT_ZONE_DIR_REPL;
193 return NF_CT_DEFAULT_ZONE_DIR;
197 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
198 struct xt_ct_target_info_v1 *info)
200 struct nf_conntrack_zone zone;
202 int ret = -EOPNOTSUPP;
204 if (info->flags & XT_CT_NOTRACK) {
209 #ifndef CONFIG_NF_CONNTRACK_ZONES
210 if (info->zone || info->flags & (XT_CT_ZONE_DIR_ORIG |
211 XT_CT_ZONE_DIR_REPL |
216 ret = nf_ct_l3proto_try_module_get(par->family);
220 memset(&zone, 0, sizeof(zone));
221 zone.id = info->zone;
222 zone.dir = xt_ct_flags_to_dir(info);
223 if (info->flags & XT_CT_ZONE_MARK)
224 zone.flags |= NF_CT_FLAG_MARK;
226 ct = nf_ct_tmpl_alloc(par->net, &zone, GFP_KERNEL);
233 if ((info->ct_events || info->exp_events) &&
234 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
240 if (info->helper[0]) {
241 ret = xt_ct_set_helper(ct, info->helper, par);
246 if (info->timeout[0]) {
247 ret = xt_ct_set_timeout(ct, par, info->timeout);
251 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
252 nf_conntrack_get(&ct->ct_general);
258 nf_conntrack_free(ct);
260 nf_ct_l3proto_module_put(par->family);
265 static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
267 struct xt_ct_target_info *info = par->targinfo;
268 struct xt_ct_target_info_v1 info_v1 = {
269 .flags = info->flags,
271 .ct_events = info->ct_events,
272 .exp_events = info->exp_events,
276 if (info->flags & ~XT_CT_NOTRACK)
279 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
281 ret = xt_ct_tg_check(par, &info_v1);
285 info->ct = info_v1.ct;
290 static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
292 struct xt_ct_target_info_v1 *info = par->targinfo;
294 if (info->flags & ~XT_CT_NOTRACK)
297 return xt_ct_tg_check(par, par->targinfo);
300 static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
302 struct xt_ct_target_info_v1 *info = par->targinfo;
304 if (info->flags & ~XT_CT_MASK)
307 return xt_ct_tg_check(par, par->targinfo);
310 static void xt_ct_destroy_timeout(struct nf_conn *ct)
312 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
313 struct nf_conn_timeout *timeout_ext;
314 typeof(nf_ct_timeout_put_hook) timeout_put;
317 timeout_put = rcu_dereference(nf_ct_timeout_put_hook);
320 timeout_ext = nf_ct_timeout_find(ct);
322 timeout_put(timeout_ext->timeout);
328 static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
329 struct xt_ct_target_info_v1 *info)
331 struct nf_conn *ct = info->ct;
332 struct nf_conn_help *help;
334 if (ct && !nf_ct_is_untracked(ct)) {
335 help = nfct_help(ct);
337 module_put(help->helper->me);
339 nf_ct_l3proto_module_put(par->family);
341 xt_ct_destroy_timeout(ct);
346 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
348 struct xt_ct_target_info *info = par->targinfo;
349 struct xt_ct_target_info_v1 info_v1 = {
350 .flags = info->flags,
352 .ct_events = info->ct_events,
353 .exp_events = info->exp_events,
356 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
358 xt_ct_tg_destroy(par, &info_v1);
361 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
363 xt_ct_tg_destroy(par, par->targinfo);
366 static struct xt_target xt_ct_tg_reg[] __read_mostly = {
369 .family = NFPROTO_UNSPEC,
370 .targetsize = sizeof(struct xt_ct_target_info),
371 .checkentry = xt_ct_tg_check_v0,
372 .destroy = xt_ct_tg_destroy_v0,
373 .target = xt_ct_target_v0,
379 .family = NFPROTO_UNSPEC,
381 .targetsize = sizeof(struct xt_ct_target_info_v1),
382 .checkentry = xt_ct_tg_check_v1,
383 .destroy = xt_ct_tg_destroy_v1,
384 .target = xt_ct_target_v1,
390 .family = NFPROTO_UNSPEC,
392 .targetsize = sizeof(struct xt_ct_target_info_v1),
393 .checkentry = xt_ct_tg_check_v2,
394 .destroy = xt_ct_tg_destroy_v1,
395 .target = xt_ct_target_v1,
402 notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
404 /* Previously seen (loopback)? Ignore. */
405 if (skb->nfct != NULL)
408 skb->nfct = &nf_ct_untracked_get()->ct_general;
409 skb->nfctinfo = IP_CT_NEW;
410 nf_conntrack_get(skb->nfct);
415 static int notrack_chk(const struct xt_tgchk_param *par)
417 if (!par->net->xt.notrack_deprecated_warning) {
418 pr_info("netfilter: NOTRACK target is deprecated, "
419 "use CT instead or upgrade iptables\n");
420 par->net->xt.notrack_deprecated_warning = true;
425 static struct xt_target notrack_tg_reg __read_mostly = {
428 .family = NFPROTO_UNSPEC,
429 .checkentry = notrack_chk,
430 .target = notrack_tg,
435 static int __init xt_ct_tg_init(void)
439 ret = xt_register_target(¬rack_tg_reg);
443 ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
445 xt_unregister_target(¬rack_tg_reg);
451 static void __exit xt_ct_tg_exit(void)
453 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
454 xt_unregister_target(¬rack_tg_reg);
457 module_init(xt_ct_tg_init);
458 module_exit(xt_ct_tg_exit);
460 MODULE_LICENSE("GPL");
461 MODULE_DESCRIPTION("Xtables: connection tracking target");
462 MODULE_ALIAS("ipt_CT");
463 MODULE_ALIAS("ip6t_CT");
464 MODULE_ALIAS("ipt_NOTRACK");
465 MODULE_ALIAS("ip6t_NOTRACK");