1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2010 Patrick McHardy <kaber@trash.net>
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6 #include <linux/module.h>
8 #include <linux/skbuff.h>
9 #include <linux/netfilter_ipv4/ip_tables.h>
10 #include <linux/netfilter_ipv6/ip6_tables.h>
11 #include <linux/netfilter/x_tables.h>
12 #include <linux/netfilter/xt_CT.h>
13 #include <net/netfilter/nf_conntrack.h>
14 #include <net/netfilter/nf_conntrack_l4proto.h>
15 #include <net/netfilter/nf_conntrack_helper.h>
16 #include <net/netfilter/nf_conntrack_ecache.h>
17 #include <net/netfilter/nf_conntrack_timeout.h>
18 #include <net/netfilter/nf_conntrack_zones.h>
20 static inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct)
22 /* Previously seen (loopback)? Ignore. */
27 atomic_inc(&ct->ct_general.use);
28 nf_ct_set(skb, ct, IP_CT_NEW);
30 nf_ct_set(skb, ct, IP_CT_UNTRACKED);
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_ratelimited("You must specify a L4 protocol and not use inversions on it\n");
86 helper = nf_conntrack_helper_try_module_get(helper_name, par->family,
89 pr_info_ratelimited("No such helper \"%s\"\n", helper_name);
93 help = nf_ct_helper_ext_add(ct, GFP_KERNEL);
95 nf_conntrack_helper_put(helper);
99 help->helper = helper;
104 xt_ct_set_timeout(struct nf_conn *ct, const struct xt_tgchk_param *par,
105 const char *timeout_name)
107 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
108 const struct nf_conntrack_l4proto *l4proto;
111 proto = xt_ct_find_proto(par);
113 pr_info_ratelimited("You must specify a L4 protocol and not "
114 "use inversions on it");
117 l4proto = nf_ct_l4proto_find(proto);
118 return nf_ct_set_timeout(par->net, ct, par->family, l4proto->l4proto,
126 static u16 xt_ct_flags_to_dir(const struct xt_ct_target_info_v1 *info)
128 switch (info->flags & (XT_CT_ZONE_DIR_ORIG |
129 XT_CT_ZONE_DIR_REPL)) {
130 case XT_CT_ZONE_DIR_ORIG:
131 return NF_CT_ZONE_DIR_ORIG;
132 case XT_CT_ZONE_DIR_REPL:
133 return NF_CT_ZONE_DIR_REPL;
135 return NF_CT_DEFAULT_ZONE_DIR;
139 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
140 struct xt_ct_target_info_v1 *info)
142 struct nf_conntrack_zone zone;
143 struct nf_conn_help *help;
145 int ret = -EOPNOTSUPP;
147 if (info->flags & XT_CT_NOTRACK) {
152 #ifndef CONFIG_NF_CONNTRACK_ZONES
153 if (info->zone || info->flags & (XT_CT_ZONE_DIR_ORIG |
154 XT_CT_ZONE_DIR_REPL |
159 ret = nf_ct_netns_get(par->net, par->family);
163 memset(&zone, 0, sizeof(zone));
164 zone.id = info->zone;
165 zone.dir = xt_ct_flags_to_dir(info);
166 if (info->flags & XT_CT_ZONE_MARK)
167 zone.flags |= NF_CT_FLAG_MARK;
169 ct = nf_ct_tmpl_alloc(par->net, &zone, GFP_KERNEL);
175 if ((info->ct_events || info->exp_events) &&
176 !nf_ct_ecache_ext_add(ct, info->ct_events, info->exp_events,
182 if (info->helper[0]) {
183 if (strnlen(info->helper, sizeof(info->helper)) == sizeof(info->helper)) {
188 ret = xt_ct_set_helper(ct, info->helper, par);
193 if (info->timeout[0]) {
194 if (strnlen(info->timeout, sizeof(info->timeout)) == sizeof(info->timeout)) {
199 ret = xt_ct_set_timeout(ct, par, info->timeout);
203 __set_bit(IPS_CONFIRMED_BIT, &ct->status);
204 nf_conntrack_get(&ct->ct_general);
210 help = nfct_help(ct);
212 nf_conntrack_helper_put(help->helper);
216 nf_ct_netns_put(par->net, par->family);
221 static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
223 struct xt_ct_target_info *info = par->targinfo;
224 struct xt_ct_target_info_v1 info_v1 = {
225 .flags = info->flags,
227 .ct_events = info->ct_events,
228 .exp_events = info->exp_events,
232 if (info->flags & ~XT_CT_NOTRACK)
235 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
237 ret = xt_ct_tg_check(par, &info_v1);
241 info->ct = info_v1.ct;
246 static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
248 struct xt_ct_target_info_v1 *info = par->targinfo;
250 if (info->flags & ~XT_CT_NOTRACK)
253 return xt_ct_tg_check(par, par->targinfo);
256 static int xt_ct_tg_check_v2(const struct xt_tgchk_param *par)
258 struct xt_ct_target_info_v1 *info = par->targinfo;
260 if (info->flags & ~XT_CT_MASK)
263 return xt_ct_tg_check(par, par->targinfo);
266 static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
267 struct xt_ct_target_info_v1 *info)
269 struct nf_conn *ct = info->ct;
270 struct nf_conn_help *help;
273 help = nfct_help(ct);
275 nf_conntrack_helper_put(help->helper);
277 nf_ct_netns_put(par->net, par->family);
279 nf_ct_destroy_timeout(ct);
284 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)
286 struct xt_ct_target_info *info = par->targinfo;
287 struct xt_ct_target_info_v1 info_v1 = {
288 .flags = info->flags,
290 .ct_events = info->ct_events,
291 .exp_events = info->exp_events,
294 memcpy(info_v1.helper, info->helper, sizeof(info->helper));
296 xt_ct_tg_destroy(par, &info_v1);
299 static void xt_ct_tg_destroy_v1(const struct xt_tgdtor_param *par)
301 xt_ct_tg_destroy(par, par->targinfo);
304 static struct xt_target xt_ct_tg_reg[] __read_mostly = {
307 .family = NFPROTO_UNSPEC,
308 .targetsize = sizeof(struct xt_ct_target_info),
309 .usersize = offsetof(struct xt_ct_target_info, ct),
310 .checkentry = xt_ct_tg_check_v0,
311 .destroy = xt_ct_tg_destroy_v0,
312 .target = xt_ct_target_v0,
318 .family = NFPROTO_UNSPEC,
320 .targetsize = sizeof(struct xt_ct_target_info_v1),
321 .usersize = offsetof(struct xt_ct_target_info, ct),
322 .checkentry = xt_ct_tg_check_v1,
323 .destroy = xt_ct_tg_destroy_v1,
324 .target = xt_ct_target_v1,
330 .family = NFPROTO_UNSPEC,
332 .targetsize = sizeof(struct xt_ct_target_info_v1),
333 .usersize = offsetof(struct xt_ct_target_info, ct),
334 .checkentry = xt_ct_tg_check_v2,
335 .destroy = xt_ct_tg_destroy_v1,
336 .target = xt_ct_target_v1,
343 notrack_tg(struct sk_buff *skb, const struct xt_action_param *par)
345 /* Previously seen (loopback)? Ignore. */
349 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
354 static int notrack_chk(const struct xt_tgchk_param *par)
356 if (!par->net->xt.notrack_deprecated_warning) {
357 pr_info("netfilter: NOTRACK target is deprecated, "
358 "use CT instead or upgrade iptables\n");
359 par->net->xt.notrack_deprecated_warning = true;
364 static struct xt_target notrack_tg_reg __read_mostly = {
367 .family = NFPROTO_UNSPEC,
368 .checkentry = notrack_chk,
369 .target = notrack_tg,
374 static int __init xt_ct_tg_init(void)
378 ret = xt_register_target(¬rack_tg_reg);
382 ret = xt_register_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
384 xt_unregister_target(¬rack_tg_reg);
390 static void __exit xt_ct_tg_exit(void)
392 xt_unregister_targets(xt_ct_tg_reg, ARRAY_SIZE(xt_ct_tg_reg));
393 xt_unregister_target(¬rack_tg_reg);
396 module_init(xt_ct_tg_init);
397 module_exit(xt_ct_tg_exit);
399 MODULE_LICENSE("GPL");
400 MODULE_DESCRIPTION("Xtables: connection tracking target");
401 MODULE_ALIAS("ipt_CT");
402 MODULE_ALIAS("ip6t_CT");
403 MODULE_ALIAS("ipt_NOTRACK");
404 MODULE_ALIAS("ip6t_NOTRACK");