1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2014 Patrick McHardy <kaber@trash.net> 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/init.h> 8 #include <linux/module.h> 9 #include <linux/netlink.h> 10 #include <linux/netfilter.h> 11 #include <linux/netfilter/nf_tables.h> 12 #include <net/netfilter/nf_tables.h> 13 #include <net/netfilter/nft_reject.h> 14 #include <net/netfilter/ipv4/nf_reject.h> 15 #include <net/netfilter/ipv6/nf_reject.h> 16 17 static void nft_reject_inet_eval(const struct nft_expr *expr, 18 struct nft_regs *regs, 19 const struct nft_pktinfo *pkt) 20 { 21 struct nft_reject *priv = nft_expr_priv(expr); 22 23 switch (nft_pf(pkt)) { 24 case NFPROTO_IPV4: 25 switch (priv->type) { 26 case NFT_REJECT_ICMP_UNREACH: 27 nf_send_unreach(pkt->skb, priv->icmp_code, 28 nft_hook(pkt)); 29 break; 30 case NFT_REJECT_TCP_RST: 31 nf_send_reset(nft_net(pkt), nft_sk(pkt), 32 pkt->skb, nft_hook(pkt)); 33 break; 34 case NFT_REJECT_ICMPX_UNREACH: 35 nf_send_unreach(pkt->skb, 36 nft_reject_icmp_code(priv->icmp_code), 37 nft_hook(pkt)); 38 break; 39 } 40 break; 41 case NFPROTO_IPV6: 42 switch (priv->type) { 43 case NFT_REJECT_ICMP_UNREACH: 44 nf_send_unreach6(nft_net(pkt), pkt->skb, 45 priv->icmp_code, nft_hook(pkt)); 46 break; 47 case NFT_REJECT_TCP_RST: 48 nf_send_reset6(nft_net(pkt), nft_sk(pkt), 49 pkt->skb, nft_hook(pkt)); 50 break; 51 case NFT_REJECT_ICMPX_UNREACH: 52 nf_send_unreach6(nft_net(pkt), pkt->skb, 53 nft_reject_icmpv6_code(priv->icmp_code), 54 nft_hook(pkt)); 55 break; 56 } 57 break; 58 } 59 60 regs->verdict.code = NF_DROP; 61 } 62 63 static int nft_reject_inet_validate(const struct nft_ctx *ctx, 64 const struct nft_expr *expr, 65 const struct nft_data **data) 66 { 67 return nft_chain_validate_hooks(ctx->chain, 68 (1 << NF_INET_LOCAL_IN) | 69 (1 << NF_INET_FORWARD) | 70 (1 << NF_INET_LOCAL_OUT) | 71 (1 << NF_INET_PRE_ROUTING) | 72 (1 << NF_INET_INGRESS)); 73 } 74 75 static struct nft_expr_type nft_reject_inet_type; 76 static const struct nft_expr_ops nft_reject_inet_ops = { 77 .type = &nft_reject_inet_type, 78 .size = NFT_EXPR_SIZE(sizeof(struct nft_reject)), 79 .eval = nft_reject_inet_eval, 80 .init = nft_reject_init, 81 .dump = nft_reject_dump, 82 .validate = nft_reject_inet_validate, 83 .reduce = NFT_REDUCE_READONLY, 84 }; 85 86 static struct nft_expr_type nft_reject_inet_type __read_mostly = { 87 .family = NFPROTO_INET, 88 .name = "reject", 89 .ops = &nft_reject_inet_ops, 90 .policy = nft_reject_policy, 91 .maxattr = NFTA_REJECT_MAX, 92 .owner = THIS_MODULE, 93 }; 94 95 static int __init nft_reject_inet_module_init(void) 96 { 97 return nft_register_expr(&nft_reject_inet_type); 98 } 99 100 static void __exit nft_reject_inet_module_exit(void) 101 { 102 nft_unregister_expr(&nft_reject_inet_type); 103 } 104 105 module_init(nft_reject_inet_module_init); 106 module_exit(nft_reject_inet_module_exit); 107 108 MODULE_LICENSE("GPL"); 109 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 110 MODULE_ALIAS_NFT_AF_EXPR(1, "reject"); 111 MODULE_DESCRIPTION("Netfilter nftables reject inet support"); 112