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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IP6 tables REJECT target module
* Linux INET6 implementation
*
* Copyright (C)2003 USAGI/WIDE Project
*
* Authors:
* Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
*
* Copyright (c) 2005-2007 Patrick McHardy <kaber@trash.net>
*
* Based on net/ipv4/netfilter/ipt_REJECT.c
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/gfp.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/icmpv6.h>
#include <linux/netdevice.h>
#include <net/icmp.h>
#include <net/flow.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter_ipv6/ip6t_REJECT.h>
#include <net/netfilter/ipv6/nf_reject.h>
MODULE_AUTHOR("Yasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>");
MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv6");
MODULE_LICENSE("GPL");
static unsigned int
reject_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct ip6t_reject_info *reject = par->targinfo;
struct net *net = xt_net(par);
switch (reject->with) {
case IP6T_ICMP6_NO_ROUTE:
nf_send_unreach6(net, skb, ICMPV6_NOROUTE, xt_hooknum(par));
break;
case IP6T_ICMP6_ADM_PROHIBITED:
nf_send_unreach6(net, skb, ICMPV6_ADM_PROHIBITED,
xt_hooknum(par));
break;
case IP6T_ICMP6_NOT_NEIGHBOUR:
nf_send_unreach6(net, skb, ICMPV6_NOT_NEIGHBOUR,
xt_hooknum(par));
break;
case IP6T_ICMP6_ADDR_UNREACH:
nf_send_unreach6(net, skb, ICMPV6_ADDR_UNREACH,
xt_hooknum(par));
break;
case IP6T_ICMP6_PORT_UNREACH:
nf_send_unreach6(net, skb, ICMPV6_PORT_UNREACH,
xt_hooknum(par));
break;
case IP6T_ICMP6_ECHOREPLY:
/* Do nothing */
break;
case IP6T_TCP_RESET:
nf_send_reset6(net, par->state->sk, skb, xt_hooknum(par));
break;
case IP6T_ICMP6_POLICY_FAIL:
nf_send_unreach6(net, skb, ICMPV6_POLICY_FAIL, xt_hooknum(par));
break;
case IP6T_ICMP6_REJECT_ROUTE:
nf_send_unreach6(net, skb, ICMPV6_REJECT_ROUTE,
xt_hooknum(par));
break;
}
return NF_DROP;
}
static int reject_tg6_check(const struct xt_tgchk_param *par)
{
const struct ip6t_reject_info *rejinfo = par->targinfo;
const struct ip6t_entry *e = par->entryinfo;
if (rejinfo->with == IP6T_ICMP6_ECHOREPLY) {
pr_info_ratelimited("ECHOREPLY is not supported\n");
return -EINVAL;
} else if (rejinfo->with == IP6T_TCP_RESET) {
/* Must specify that it's a TCP packet */
if (!(e->ipv6.flags & IP6T_F_PROTO) ||
e->ipv6.proto != IPPROTO_TCP ||
(e->ipv6.invflags & XT_INV_PROTO)) {
pr_info_ratelimited("TCP_RESET illegal for non-tcp\n");
return -EINVAL;
}
}
return 0;
}
static struct xt_target reject_tg6_reg __read_mostly = {
.name = "REJECT",
.family = NFPROTO_IPV6,
.target = reject_tg6,
.targetsize = sizeof(struct ip6t_reject_info),
.table = "filter",
.hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
(1 << NF_INET_LOCAL_OUT),
.checkentry = reject_tg6_check,
.me = THIS_MODULE
};
static int __init reject_tg6_init(void)
{
return xt_register_target(&reject_tg6_reg);
}
static void __exit reject_tg6_exit(void)
{
xt_unregister_target(&reject_tg6_reg);
}
module_init(reject_tg6_init);
module_exit(reject_tg6_exit);
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