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 u8 dreg; 14 }; 15 }; 16 17 static void nft_socket_wildcard(const struct nft_pktinfo *pkt, 18 struct nft_regs *regs, struct sock *sk, 19 u32 *dest) 20 { 21 switch (nft_pf(pkt)) { 22 case NFPROTO_IPV4: 23 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0); 24 break; 25 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 26 case NFPROTO_IPV6: 27 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr)); 28 break; 29 #endif 30 default: 31 regs->verdict.code = NFT_BREAK; 32 return; 33 } 34 } 35 36 static void nft_socket_eval(const struct nft_expr *expr, 37 struct nft_regs *regs, 38 const struct nft_pktinfo *pkt) 39 { 40 const struct nft_socket *priv = nft_expr_priv(expr); 41 struct sk_buff *skb = pkt->skb; 42 struct sock *sk = skb->sk; 43 u32 *dest = ®s->data[priv->dreg]; 44 45 if (sk && !net_eq(nft_net(pkt), sock_net(sk))) 46 sk = NULL; 47 48 if (!sk) 49 switch(nft_pf(pkt)) { 50 case NFPROTO_IPV4: 51 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt)); 52 break; 53 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 54 case NFPROTO_IPV6: 55 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt)); 56 break; 57 #endif 58 default: 59 WARN_ON_ONCE(1); 60 regs->verdict.code = NFT_BREAK; 61 return; 62 } 63 64 if (!sk) { 65 regs->verdict.code = NFT_BREAK; 66 return; 67 } 68 69 switch(priv->key) { 70 case NFT_SOCKET_TRANSPARENT: 71 nft_reg_store8(dest, inet_sk_transparent(sk)); 72 break; 73 case NFT_SOCKET_MARK: 74 if (sk_fullsock(sk)) { 75 *dest = sk->sk_mark; 76 } else { 77 regs->verdict.code = NFT_BREAK; 78 return; 79 } 80 break; 81 case NFT_SOCKET_WILDCARD: 82 if (!sk_fullsock(sk)) { 83 regs->verdict.code = NFT_BREAK; 84 return; 85 } 86 nft_socket_wildcard(pkt, regs, sk, dest); 87 break; 88 default: 89 WARN_ON(1); 90 regs->verdict.code = NFT_BREAK; 91 } 92 93 if (sk != skb->sk) 94 sock_gen_put(sk); 95 } 96 97 static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { 98 [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, 99 [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, 100 }; 101 102 static int nft_socket_init(const struct nft_ctx *ctx, 103 const struct nft_expr *expr, 104 const struct nlattr * const tb[]) 105 { 106 struct nft_socket *priv = nft_expr_priv(expr); 107 unsigned int len; 108 109 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) 110 return -EINVAL; 111 112 switch(ctx->family) { 113 case NFPROTO_IPV4: 114 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 115 case NFPROTO_IPV6: 116 #endif 117 case NFPROTO_INET: 118 break; 119 default: 120 return -EOPNOTSUPP; 121 } 122 123 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY])); 124 switch(priv->key) { 125 case NFT_SOCKET_TRANSPARENT: 126 case NFT_SOCKET_WILDCARD: 127 len = sizeof(u8); 128 break; 129 case NFT_SOCKET_MARK: 130 len = sizeof(u32); 131 break; 132 default: 133 return -EOPNOTSUPP; 134 } 135 136 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, 137 NULL, NFT_DATA_VALUE, len); 138 } 139 140 static int nft_socket_dump(struct sk_buff *skb, 141 const struct nft_expr *expr) 142 { 143 const struct nft_socket *priv = nft_expr_priv(expr); 144 145 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) 146 return -1; 147 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) 148 return -1; 149 return 0; 150 } 151 152 static struct nft_expr_type nft_socket_type; 153 static const struct nft_expr_ops nft_socket_ops = { 154 .type = &nft_socket_type, 155 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), 156 .eval = nft_socket_eval, 157 .init = nft_socket_init, 158 .dump = nft_socket_dump, 159 }; 160 161 static struct nft_expr_type nft_socket_type __read_mostly = { 162 .name = "socket", 163 .ops = &nft_socket_ops, 164 .policy = nft_socket_policy, 165 .maxattr = NFTA_SOCKET_MAX, 166 .owner = THIS_MODULE, 167 }; 168 169 static int __init nft_socket_module_init(void) 170 { 171 return nft_register_expr(&nft_socket_type); 172 } 173 174 static void __exit nft_socket_module_exit(void) 175 { 176 nft_unregister_expr(&nft_socket_type); 177 } 178 179 module_init(nft_socket_module_init); 180 module_exit(nft_socket_module_exit); 181 182 MODULE_LICENSE("GPL"); 183 MODULE_AUTHOR("Máté Eckl"); 184 MODULE_DESCRIPTION("nf_tables socket match module"); 185 MODULE_ALIAS_NFT_EXPR("socket"); 186