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 u8 level; 13 union { 14 u8 dreg; 15 }; 16 }; 17 18 static void nft_socket_wildcard(const struct nft_pktinfo *pkt, 19 struct nft_regs *regs, struct sock *sk, 20 u32 *dest) 21 { 22 switch (nft_pf(pkt)) { 23 case NFPROTO_IPV4: 24 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0); 25 break; 26 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 27 case NFPROTO_IPV6: 28 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr)); 29 break; 30 #endif 31 default: 32 regs->verdict.code = NFT_BREAK; 33 return; 34 } 35 } 36 37 #ifdef CONFIG_SOCK_CGROUP_DATA 38 static noinline bool 39 nft_sock_get_eval_cgroupv2(u32 *dest, const struct nft_pktinfo *pkt, u32 level) 40 { 41 struct sock *sk = skb_to_full_sk(pkt->skb); 42 struct cgroup *cgrp; 43 44 if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk))) 45 return false; 46 47 cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); 48 if (level > cgrp->level) 49 return false; 50 51 memcpy(dest, &cgrp->ancestor_ids[level], sizeof(u64)); 52 53 return true; 54 } 55 #endif 56 57 static void nft_socket_eval(const struct nft_expr *expr, 58 struct nft_regs *regs, 59 const struct nft_pktinfo *pkt) 60 { 61 const struct nft_socket *priv = nft_expr_priv(expr); 62 struct sk_buff *skb = pkt->skb; 63 struct sock *sk = skb->sk; 64 u32 *dest = ®s->data[priv->dreg]; 65 66 if (sk && !net_eq(nft_net(pkt), sock_net(sk))) 67 sk = NULL; 68 69 if (!sk) 70 switch(nft_pf(pkt)) { 71 case NFPROTO_IPV4: 72 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt)); 73 break; 74 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 75 case NFPROTO_IPV6: 76 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt)); 77 break; 78 #endif 79 default: 80 WARN_ON_ONCE(1); 81 regs->verdict.code = NFT_BREAK; 82 return; 83 } 84 85 if (!sk) { 86 regs->verdict.code = NFT_BREAK; 87 return; 88 } 89 90 switch(priv->key) { 91 case NFT_SOCKET_TRANSPARENT: 92 nft_reg_store8(dest, inet_sk_transparent(sk)); 93 break; 94 case NFT_SOCKET_MARK: 95 if (sk_fullsock(sk)) { 96 *dest = sk->sk_mark; 97 } else { 98 regs->verdict.code = NFT_BREAK; 99 return; 100 } 101 break; 102 case NFT_SOCKET_WILDCARD: 103 if (!sk_fullsock(sk)) { 104 regs->verdict.code = NFT_BREAK; 105 return; 106 } 107 nft_socket_wildcard(pkt, regs, sk, dest); 108 break; 109 #ifdef CONFIG_SOCK_CGROUP_DATA 110 case NFT_SOCKET_CGROUPV2: 111 if (!nft_sock_get_eval_cgroupv2(dest, pkt, priv->level)) { 112 regs->verdict.code = NFT_BREAK; 113 return; 114 } 115 break; 116 #endif 117 default: 118 WARN_ON(1); 119 regs->verdict.code = NFT_BREAK; 120 } 121 122 if (sk != skb->sk) 123 sock_gen_put(sk); 124 } 125 126 static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { 127 [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, 128 [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, 129 [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 }, 130 }; 131 132 static int nft_socket_init(const struct nft_ctx *ctx, 133 const struct nft_expr *expr, 134 const struct nlattr * const tb[]) 135 { 136 struct nft_socket *priv = nft_expr_priv(expr); 137 unsigned int len; 138 139 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) 140 return -EINVAL; 141 142 switch(ctx->family) { 143 case NFPROTO_IPV4: 144 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 145 case NFPROTO_IPV6: 146 #endif 147 case NFPROTO_INET: 148 break; 149 default: 150 return -EOPNOTSUPP; 151 } 152 153 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY])); 154 switch(priv->key) { 155 case NFT_SOCKET_TRANSPARENT: 156 case NFT_SOCKET_WILDCARD: 157 len = sizeof(u8); 158 break; 159 case NFT_SOCKET_MARK: 160 len = sizeof(u32); 161 break; 162 #ifdef CONFIG_CGROUPS 163 case NFT_SOCKET_CGROUPV2: { 164 unsigned int level; 165 166 if (!tb[NFTA_SOCKET_LEVEL]) 167 return -EINVAL; 168 169 level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL])); 170 if (level > 255) 171 return -EOPNOTSUPP; 172 173 priv->level = level; 174 len = sizeof(u64); 175 break; 176 } 177 #endif 178 default: 179 return -EOPNOTSUPP; 180 } 181 182 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, 183 NULL, NFT_DATA_VALUE, len); 184 } 185 186 static int nft_socket_dump(struct sk_buff *skb, 187 const struct nft_expr *expr) 188 { 189 const struct nft_socket *priv = nft_expr_priv(expr); 190 191 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) 192 return -1; 193 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) 194 return -1; 195 if (priv->key == NFT_SOCKET_CGROUPV2 && 196 nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level))) 197 return -1; 198 return 0; 199 } 200 201 static struct nft_expr_type nft_socket_type; 202 static const struct nft_expr_ops nft_socket_ops = { 203 .type = &nft_socket_type, 204 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), 205 .eval = nft_socket_eval, 206 .init = nft_socket_init, 207 .dump = nft_socket_dump, 208 }; 209 210 static struct nft_expr_type nft_socket_type __read_mostly = { 211 .name = "socket", 212 .ops = &nft_socket_ops, 213 .policy = nft_socket_policy, 214 .maxattr = NFTA_SOCKET_MAX, 215 .owner = THIS_MODULE, 216 }; 217 218 static int __init nft_socket_module_init(void) 219 { 220 return nft_register_expr(&nft_socket_type); 221 } 222 223 static void __exit nft_socket_module_exit(void) 224 { 225 nft_unregister_expr(&nft_socket_type); 226 } 227 228 module_init(nft_socket_module_init); 229 module_exit(nft_socket_module_exit); 230 231 MODULE_LICENSE("GPL"); 232 MODULE_AUTHOR("Máté Eckl"); 233 MODULE_DESCRIPTION("nf_tables socket match module"); 234 MODULE_ALIAS_NFT_EXPR("socket"); 235