1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * IP6 tables REJECT target module |
4 | * Linux INET6 implementation |
5 | * |
6 | * Copyright (C)2003 USAGI/WIDE Project |
7 | * |
8 | * Authors: |
9 | * Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> |
10 | * |
11 | * Copyright (c) 2005-2007 Patrick McHardy <kaber@trash.net> |
12 | * |
13 | * Based on net/ipv4/netfilter/ipt_REJECT.c |
14 | */ |
15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
16 | |
17 | #include <linux/gfp.h> |
18 | #include <linux/module.h> |
19 | #include <linux/skbuff.h> |
20 | #include <linux/icmpv6.h> |
21 | #include <linux/netdevice.h> |
22 | #include <net/icmp.h> |
23 | #include <net/flow.h> |
24 | #include <linux/netfilter/x_tables.h> |
25 | #include <linux/netfilter_ipv6/ip6_tables.h> |
26 | #include <linux/netfilter_ipv6/ip6t_REJECT.h> |
27 | |
28 | #include <net/netfilter/ipv6/nf_reject.h> |
29 | |
30 | MODULE_AUTHOR("Yasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>" ); |
31 | MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv6" ); |
32 | MODULE_LICENSE("GPL" ); |
33 | |
34 | static unsigned int |
35 | reject_tg6(struct sk_buff *skb, const struct xt_action_param *par) |
36 | { |
37 | const struct ip6t_reject_info *reject = par->targinfo; |
38 | struct net *net = xt_net(par); |
39 | |
40 | switch (reject->with) { |
41 | case IP6T_ICMP6_NO_ROUTE: |
42 | nf_send_unreach6(net, skb_in: skb, ICMPV6_NOROUTE, hooknum: xt_hooknum(par)); |
43 | break; |
44 | case IP6T_ICMP6_ADM_PROHIBITED: |
45 | nf_send_unreach6(net, skb_in: skb, ICMPV6_ADM_PROHIBITED, |
46 | hooknum: xt_hooknum(par)); |
47 | break; |
48 | case IP6T_ICMP6_NOT_NEIGHBOUR: |
49 | nf_send_unreach6(net, skb_in: skb, ICMPV6_NOT_NEIGHBOUR, |
50 | hooknum: xt_hooknum(par)); |
51 | break; |
52 | case IP6T_ICMP6_ADDR_UNREACH: |
53 | nf_send_unreach6(net, skb_in: skb, ICMPV6_ADDR_UNREACH, |
54 | hooknum: xt_hooknum(par)); |
55 | break; |
56 | case IP6T_ICMP6_PORT_UNREACH: |
57 | nf_send_unreach6(net, skb_in: skb, ICMPV6_PORT_UNREACH, |
58 | hooknum: xt_hooknum(par)); |
59 | break; |
60 | case IP6T_ICMP6_ECHOREPLY: |
61 | /* Do nothing */ |
62 | break; |
63 | case IP6T_TCP_RESET: |
64 | nf_send_reset6(net, sk: par->state->sk, oldskb: skb, hook: xt_hooknum(par)); |
65 | break; |
66 | case IP6T_ICMP6_POLICY_FAIL: |
67 | nf_send_unreach6(net, skb_in: skb, ICMPV6_POLICY_FAIL, hooknum: xt_hooknum(par)); |
68 | break; |
69 | case IP6T_ICMP6_REJECT_ROUTE: |
70 | nf_send_unreach6(net, skb_in: skb, ICMPV6_REJECT_ROUTE, |
71 | hooknum: xt_hooknum(par)); |
72 | break; |
73 | } |
74 | |
75 | return NF_DROP; |
76 | } |
77 | |
78 | static int reject_tg6_check(const struct xt_tgchk_param *par) |
79 | { |
80 | const struct ip6t_reject_info *rejinfo = par->targinfo; |
81 | const struct ip6t_entry *e = par->entryinfo; |
82 | |
83 | if (rejinfo->with == IP6T_ICMP6_ECHOREPLY) { |
84 | pr_info_ratelimited("ECHOREPLY is not supported\n" ); |
85 | return -EINVAL; |
86 | } else if (rejinfo->with == IP6T_TCP_RESET) { |
87 | /* Must specify that it's a TCP packet */ |
88 | if (!(e->ipv6.flags & IP6T_F_PROTO) || |
89 | e->ipv6.proto != IPPROTO_TCP || |
90 | (e->ipv6.invflags & XT_INV_PROTO)) { |
91 | pr_info_ratelimited("TCP_RESET illegal for non-tcp\n" ); |
92 | return -EINVAL; |
93 | } |
94 | } |
95 | return 0; |
96 | } |
97 | |
98 | static struct xt_target reject_tg6_reg __read_mostly = { |
99 | .name = "REJECT" , |
100 | .family = NFPROTO_IPV6, |
101 | .target = reject_tg6, |
102 | .targetsize = sizeof(struct ip6t_reject_info), |
103 | .table = "filter" , |
104 | .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) | |
105 | (1 << NF_INET_LOCAL_OUT), |
106 | .checkentry = reject_tg6_check, |
107 | .me = THIS_MODULE |
108 | }; |
109 | |
110 | static int __init reject_tg6_init(void) |
111 | { |
112 | return xt_register_target(target: &reject_tg6_reg); |
113 | } |
114 | |
115 | static void __exit reject_tg6_exit(void) |
116 | { |
117 | xt_unregister_target(target: &reject_tg6_reg); |
118 | } |
119 | |
120 | module_init(reject_tg6_init); |
121 | module_exit(reject_tg6_exit); |
122 | |