Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2014 Patrick McHardy <kaber@trash.net> |
| 3 | * |
| 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. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/kernel.h> |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/netlink.h> |
| 13 | #include <linux/netfilter.h> |
| 14 | #include <linux/netfilter/nf_tables.h> |
| 15 | #include <net/netfilter/nf_tables.h> |
| 16 | #include <net/netfilter/nft_reject.h> |
Pablo Neira Ayuso | 51b0a5d | 2014-09-26 14:35:14 +0200 | [diff] [blame] | 17 | #include <net/netfilter/ipv4/nf_reject.h> |
| 18 | #include <net/netfilter/ipv6/nf_reject.h> |
Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 19 | |
| 20 | static void nft_reject_inet_eval(const struct nft_expr *expr, |
| 21 | struct nft_data data[NFT_REG_MAX + 1], |
| 22 | const struct nft_pktinfo *pkt) |
| 23 | { |
Pablo Neira Ayuso | 51b0a5d | 2014-09-26 14:35:14 +0200 | [diff] [blame] | 24 | struct nft_reject *priv = nft_expr_priv(expr); |
| 25 | struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out); |
| 26 | |
Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 27 | switch (pkt->ops->pf) { |
| 28 | case NFPROTO_IPV4: |
Pablo Neira Ayuso | 51b0a5d | 2014-09-26 14:35:14 +0200 | [diff] [blame] | 29 | switch (priv->type) { |
| 30 | case NFT_REJECT_ICMP_UNREACH: |
| 31 | nf_send_unreach(pkt->skb, priv->icmp_code); |
| 32 | break; |
| 33 | case NFT_REJECT_TCP_RST: |
| 34 | nf_send_reset(pkt->skb, pkt->ops->hooknum); |
| 35 | break; |
| 36 | case NFT_REJECT_ICMPX_UNREACH: |
| 37 | nf_send_unreach(pkt->skb, |
| 38 | nft_reject_icmp_code(priv->icmp_code)); |
| 39 | break; |
| 40 | } |
| 41 | break; |
Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 42 | case NFPROTO_IPV6: |
Pablo Neira Ayuso | 51b0a5d | 2014-09-26 14:35:14 +0200 | [diff] [blame] | 43 | switch (priv->type) { |
| 44 | case NFT_REJECT_ICMP_UNREACH: |
| 45 | nf_send_unreach6(net, pkt->skb, priv->icmp_code, |
| 46 | pkt->ops->hooknum); |
| 47 | break; |
| 48 | case NFT_REJECT_TCP_RST: |
| 49 | nf_send_reset6(net, pkt->skb, pkt->ops->hooknum); |
| 50 | break; |
| 51 | case NFT_REJECT_ICMPX_UNREACH: |
| 52 | nf_send_unreach6(net, pkt->skb, |
| 53 | nft_reject_icmpv6_code(priv->icmp_code), |
| 54 | pkt->ops->hooknum); |
| 55 | break; |
| 56 | } |
| 57 | break; |
Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 58 | } |
Pablo Neira Ayuso | 51b0a5d | 2014-09-26 14:35:14 +0200 | [diff] [blame] | 59 | data[NFT_REG_VERDICT].verdict = NF_DROP; |
| 60 | } |
| 61 | |
| 62 | static int nft_reject_inet_init(const struct nft_ctx *ctx, |
| 63 | const struct nft_expr *expr, |
| 64 | const struct nlattr * const tb[]) |
| 65 | { |
| 66 | struct nft_reject *priv = nft_expr_priv(expr); |
| 67 | int icmp_code; |
| 68 | |
| 69 | if (tb[NFTA_REJECT_TYPE] == NULL) |
| 70 | return -EINVAL; |
| 71 | |
| 72 | priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE])); |
| 73 | switch (priv->type) { |
| 74 | case NFT_REJECT_ICMP_UNREACH: |
| 75 | case NFT_REJECT_ICMPX_UNREACH: |
| 76 | if (tb[NFTA_REJECT_ICMP_CODE] == NULL) |
| 77 | return -EINVAL; |
| 78 | |
| 79 | icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]); |
| 80 | if (priv->type == NFT_REJECT_ICMPX_UNREACH && |
| 81 | icmp_code > NFT_REJECT_ICMPX_MAX) |
| 82 | return -EINVAL; |
| 83 | |
| 84 | priv->icmp_code = icmp_code; |
| 85 | break; |
| 86 | case NFT_REJECT_TCP_RST: |
| 87 | break; |
| 88 | default: |
| 89 | return -EINVAL; |
| 90 | } |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | static int nft_reject_inet_dump(struct sk_buff *skb, |
| 95 | const struct nft_expr *expr) |
| 96 | { |
| 97 | const struct nft_reject *priv = nft_expr_priv(expr); |
| 98 | |
| 99 | if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type))) |
| 100 | goto nla_put_failure; |
| 101 | |
| 102 | switch (priv->type) { |
| 103 | case NFT_REJECT_ICMP_UNREACH: |
| 104 | case NFT_REJECT_ICMPX_UNREACH: |
| 105 | if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code)) |
| 106 | goto nla_put_failure; |
| 107 | break; |
| 108 | } |
| 109 | |
| 110 | return 0; |
| 111 | |
| 112 | nla_put_failure: |
| 113 | return -1; |
Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 114 | } |
| 115 | |
| 116 | static struct nft_expr_type nft_reject_inet_type; |
| 117 | static const struct nft_expr_ops nft_reject_inet_ops = { |
| 118 | .type = &nft_reject_inet_type, |
| 119 | .size = NFT_EXPR_SIZE(sizeof(struct nft_reject)), |
| 120 | .eval = nft_reject_inet_eval, |
Pablo Neira Ayuso | 51b0a5d | 2014-09-26 14:35:14 +0200 | [diff] [blame] | 121 | .init = nft_reject_inet_init, |
| 122 | .dump = nft_reject_inet_dump, |
Patrick McHardy | 05513e9 | 2014-02-05 15:03:39 +0000 | [diff] [blame] | 123 | }; |
| 124 | |
| 125 | static struct nft_expr_type nft_reject_inet_type __read_mostly = { |
| 126 | .family = NFPROTO_INET, |
| 127 | .name = "reject", |
| 128 | .ops = &nft_reject_inet_ops, |
| 129 | .policy = nft_reject_policy, |
| 130 | .maxattr = NFTA_REJECT_MAX, |
| 131 | .owner = THIS_MODULE, |
| 132 | }; |
| 133 | |
| 134 | static int __init nft_reject_inet_module_init(void) |
| 135 | { |
| 136 | return nft_register_expr(&nft_reject_inet_type); |
| 137 | } |
| 138 | |
| 139 | static void __exit nft_reject_inet_module_exit(void) |
| 140 | { |
| 141 | nft_unregister_expr(&nft_reject_inet_type); |
| 142 | } |
| 143 | |
| 144 | module_init(nft_reject_inet_module_init); |
| 145 | module_exit(nft_reject_inet_module_exit); |
| 146 | |
| 147 | MODULE_LICENSE("GPL"); |
| 148 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 149 | MODULE_ALIAS_NFT_AF_EXPR(1, "reject"); |