1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #include <linux/module.h> 3 #include <linux/netfilter/nf_tables.h> 4 #include <net/netfilter/nf_tables.h> 5 #include <net/netfilter/nf_tables_core.h> 6 #include <net/netfilter/nf_socket.h> 7 #include <net/inet_sock.h> 8 #include <net/tcp.h> 9 10 struct nft_socket { 11 enum nft_socket_keys key:8; 12 union { 13 enum nft_registers dreg:8; 14 }; 15 }; 16 17 static void nft_socket_eval(const struct nft_expr *expr, 18 struct nft_regs *regs, 19 const struct nft_pktinfo *pkt) 20 { 21 const struct nft_socket *priv = nft_expr_priv(expr); 22 struct sk_buff *skb = pkt->skb; 23 struct sock *sk = skb->sk; 24 u32 *dest = ®s->data[priv->dreg]; 25 26 if (sk && !net_eq(nft_net(pkt), sock_net(sk))) 27 sk = NULL; 28 29 if (!sk) 30 switch(nft_pf(pkt)) { 31 case NFPROTO_IPV4: 32 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt)); 33 break; 34 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 35 case NFPROTO_IPV6: 36 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt)); 37 break; 38 #endif 39 default: 40 WARN_ON_ONCE(1); 41 regs->verdict.code = NFT_BREAK; 42 return; 43 } 44 45 if (!sk) { 46 regs->verdict.code = NFT_BREAK; 47 return; 48 } 49 50 switch(priv->key) { 51 case NFT_SOCKET_TRANSPARENT: 52 nft_reg_store8(dest, inet_sk_transparent(sk)); 53 break; 54 case NFT_SOCKET_MARK: 55 if (sk_fullsock(sk)) { 56 *dest = sk->sk_mark; 57 } else { 58 regs->verdict.code = NFT_BREAK; 59 return; 60 } 61 break; 62 default: 63 WARN_ON(1); 64 regs->verdict.code = NFT_BREAK; 65 } 66 67 if (sk != skb->sk) 68 sock_gen_put(sk); 69 } 70 71 static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { 72 [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, 73 [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, 74 }; 75 76 static int nft_socket_init(const struct nft_ctx *ctx, 77 const struct nft_expr *expr, 78 const struct nlattr * const tb[]) 79 { 80 struct nft_socket *priv = nft_expr_priv(expr); 81 unsigned int len; 82 83 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) 84 return -EINVAL; 85 86 switch(ctx->family) { 87 case NFPROTO_IPV4: 88 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 89 case NFPROTO_IPV6: 90 #endif 91 case NFPROTO_INET: 92 break; 93 default: 94 return -EOPNOTSUPP; 95 } 96 97 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY])); 98 switch(priv->key) { 99 case NFT_SOCKET_TRANSPARENT: 100 len = sizeof(u8); 101 break; 102 case NFT_SOCKET_MARK: 103 len = sizeof(u32); 104 break; 105 default: 106 return -EOPNOTSUPP; 107 } 108 109 priv->dreg = nft_parse_register(tb[NFTA_SOCKET_DREG]); 110 return nft_validate_register_store(ctx, priv->dreg, NULL, 111 NFT_DATA_VALUE, len); 112 } 113 114 static int nft_socket_dump(struct sk_buff *skb, 115 const struct nft_expr *expr) 116 { 117 const struct nft_socket *priv = nft_expr_priv(expr); 118 119 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) 120 return -1; 121 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) 122 return -1; 123 return 0; 124 } 125 126 static struct nft_expr_type nft_socket_type; 127 static const struct nft_expr_ops nft_socket_ops = { 128 .type = &nft_socket_type, 129 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), 130 .eval = nft_socket_eval, 131 .init = nft_socket_init, 132 .dump = nft_socket_dump, 133 }; 134 135 static struct nft_expr_type nft_socket_type __read_mostly = { 136 .name = "socket", 137 .ops = &nft_socket_ops, 138 .policy = nft_socket_policy, 139 .maxattr = NFTA_SOCKET_MAX, 140 .owner = THIS_MODULE, 141 }; 142 143 static int __init nft_socket_module_init(void) 144 { 145 return nft_register_expr(&nft_socket_type); 146 } 147 148 static void __exit nft_socket_module_exit(void) 149 { 150 nft_unregister_expr(&nft_socket_type); 151 } 152 153 module_init(nft_socket_module_init); 154 module_exit(nft_socket_module_exit); 155 156 MODULE_LICENSE("GPL"); 157 MODULE_AUTHOR("Máté Eckl"); 158 MODULE_DESCRIPTION("nf_tables socket match module"); 159 MODULE_ALIAS_NFT_EXPR("socket"); 160