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 u8 len; 14 union { 15 u8 dreg; 16 }; 17 }; 18 19 static void nft_socket_wildcard(const struct nft_pktinfo *pkt, 20 struct nft_regs *regs, struct sock *sk, 21 u32 *dest) 22 { 23 switch (nft_pf(pkt)) { 24 case NFPROTO_IPV4: 25 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0); 26 break; 27 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 28 case NFPROTO_IPV6: 29 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr)); 30 break; 31 #endif 32 default: 33 regs->verdict.code = NFT_BREAK; 34 return; 35 } 36 } 37 38 #ifdef CONFIG_SOCK_CGROUP_DATA 39 static noinline bool 40 nft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo *pkt, u32 level) 41 { 42 struct cgroup *cgrp; 43 u64 cgid; 44 45 if (!sk_fullsock(sk)) 46 return false; 47 48 cgrp = cgroup_ancestor(sock_cgroup_ptr(&sk->sk_cgrp_data), level); 49 if (!cgrp) 50 return false; 51 52 cgid = cgroup_id(cgrp); 53 memcpy(dest, &cgid, sizeof(u64)); 54 return true; 55 } 56 #endif 57 58 static struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt) 59 { 60 const struct net_device *indev = nft_in(pkt); 61 const struct sk_buff *skb = pkt->skb; 62 struct sock *sk = NULL; 63 64 if (!indev) 65 return NULL; 66 67 switch (nft_pf(pkt)) { 68 case NFPROTO_IPV4: 69 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev); 70 break; 71 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 72 case NFPROTO_IPV6: 73 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev); 74 break; 75 #endif 76 default: 77 WARN_ON_ONCE(1); 78 break; 79 } 80 81 return sk; 82 } 83 84 static void nft_socket_eval(const struct nft_expr *expr, 85 struct nft_regs *regs, 86 const struct nft_pktinfo *pkt) 87 { 88 const struct nft_socket *priv = nft_expr_priv(expr); 89 struct sk_buff *skb = pkt->skb; 90 struct sock *sk = skb->sk; 91 u32 *dest = ®s->data[priv->dreg]; 92 93 if (sk && !net_eq(nft_net(pkt), sock_net(sk))) 94 sk = NULL; 95 96 if (!sk) 97 sk = nft_socket_do_lookup(pkt); 98 99 if (!sk) { 100 regs->verdict.code = NFT_BREAK; 101 return; 102 } 103 104 switch(priv->key) { 105 case NFT_SOCKET_TRANSPARENT: 106 nft_reg_store8(dest, inet_sk_transparent(sk)); 107 break; 108 case NFT_SOCKET_MARK: 109 if (sk_fullsock(sk)) { 110 *dest = sk->sk_mark; 111 } else { 112 regs->verdict.code = NFT_BREAK; 113 return; 114 } 115 break; 116 case NFT_SOCKET_WILDCARD: 117 if (!sk_fullsock(sk)) { 118 regs->verdict.code = NFT_BREAK; 119 return; 120 } 121 nft_socket_wildcard(pkt, regs, sk, dest); 122 break; 123 #ifdef CONFIG_SOCK_CGROUP_DATA 124 case NFT_SOCKET_CGROUPV2: 125 if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) { 126 regs->verdict.code = NFT_BREAK; 127 return; 128 } 129 break; 130 #endif 131 default: 132 WARN_ON(1); 133 regs->verdict.code = NFT_BREAK; 134 } 135 136 if (sk != skb->sk) 137 sock_gen_put(sk); 138 } 139 140 static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { 141 [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, 142 [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, 143 [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 }, 144 }; 145 146 static int nft_socket_init(const struct nft_ctx *ctx, 147 const struct nft_expr *expr, 148 const struct nlattr * const tb[]) 149 { 150 struct nft_socket *priv = nft_expr_priv(expr); 151 unsigned int len; 152 153 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) 154 return -EINVAL; 155 156 switch(ctx->family) { 157 case NFPROTO_IPV4: 158 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 159 case NFPROTO_IPV6: 160 #endif 161 case NFPROTO_INET: 162 break; 163 default: 164 return -EOPNOTSUPP; 165 } 166 167 priv->key = ntohl(nla_get_be32(tb[NFTA_SOCKET_KEY])); 168 switch(priv->key) { 169 case NFT_SOCKET_TRANSPARENT: 170 case NFT_SOCKET_WILDCARD: 171 len = sizeof(u8); 172 break; 173 case NFT_SOCKET_MARK: 174 len = sizeof(u32); 175 break; 176 #ifdef CONFIG_CGROUPS 177 case NFT_SOCKET_CGROUPV2: { 178 unsigned int level; 179 180 if (!tb[NFTA_SOCKET_LEVEL]) 181 return -EINVAL; 182 183 level = ntohl(nla_get_be32(tb[NFTA_SOCKET_LEVEL])); 184 if (level > 255) 185 return -EOPNOTSUPP; 186 187 priv->level = level; 188 len = sizeof(u64); 189 break; 190 } 191 #endif 192 default: 193 return -EOPNOTSUPP; 194 } 195 196 priv->len = len; 197 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, 198 NULL, NFT_DATA_VALUE, len); 199 } 200 201 static int nft_socket_dump(struct sk_buff *skb, 202 const struct nft_expr *expr) 203 { 204 const struct nft_socket *priv = nft_expr_priv(expr); 205 206 if (nla_put_be32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) 207 return -1; 208 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) 209 return -1; 210 if (priv->key == NFT_SOCKET_CGROUPV2 && 211 nla_put_be32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level))) 212 return -1; 213 return 0; 214 } 215 216 static bool nft_socket_reduce(struct nft_regs_track *track, 217 const struct nft_expr *expr) 218 { 219 const struct nft_socket *priv = nft_expr_priv(expr); 220 const struct nft_socket *socket; 221 222 if (!nft_reg_track_cmp(track, expr, priv->dreg)) { 223 nft_reg_track_update(track, expr, priv->dreg, priv->len); 224 return false; 225 } 226 227 socket = nft_expr_priv(track->regs[priv->dreg].selector); 228 if (priv->key != socket->key || 229 priv->dreg != socket->dreg || 230 priv->level != socket->level) { 231 nft_reg_track_update(track, expr, priv->dreg, priv->len); 232 return false; 233 } 234 235 if (!track->regs[priv->dreg].bitwise) 236 return true; 237 238 return nft_expr_reduce_bitwise(track, expr); 239 } 240 241 static int nft_socket_validate(const struct nft_ctx *ctx, 242 const struct nft_expr *expr, 243 const struct nft_data **data) 244 { 245 return nft_chain_validate_hooks(ctx->chain, 246 (1 << NF_INET_PRE_ROUTING) | 247 (1 << NF_INET_LOCAL_IN) | 248 (1 << NF_INET_LOCAL_OUT)); 249 } 250 251 static struct nft_expr_type nft_socket_type; 252 static const struct nft_expr_ops nft_socket_ops = { 253 .type = &nft_socket_type, 254 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), 255 .eval = nft_socket_eval, 256 .init = nft_socket_init, 257 .dump = nft_socket_dump, 258 .validate = nft_socket_validate, 259 .reduce = nft_socket_reduce, 260 }; 261 262 static struct nft_expr_type nft_socket_type __read_mostly = { 263 .name = "socket", 264 .ops = &nft_socket_ops, 265 .policy = nft_socket_policy, 266 .maxattr = NFTA_SOCKET_MAX, 267 .owner = THIS_MODULE, 268 }; 269 270 static int __init nft_socket_module_init(void) 271 { 272 return nft_register_expr(&nft_socket_type); 273 } 274 275 static void __exit nft_socket_module_exit(void) 276 { 277 nft_unregister_expr(&nft_socket_type); 278 } 279 280 module_init(nft_socket_module_init); 281 module_exit(nft_socket_module_exit); 282 283 MODULE_LICENSE("GPL"); 284 MODULE_AUTHOR("Máté Eckl"); 285 MODULE_DESCRIPTION("nf_tables socket match module"); 286 MODULE_ALIAS_NFT_EXPR("socket"); 287