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 44 if (!sk_fullsock(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 struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt) 58 { 59 const struct net_device *indev = nft_in(pkt); 60 const struct sk_buff *skb = pkt->skb; 61 struct sock *sk = NULL; 62 63 if (!indev) 64 return NULL; 65 66 switch (nft_pf(pkt)) { 67 case NFPROTO_IPV4: 68 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev); 69 break; 70 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 71 case NFPROTO_IPV6: 72 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev); 73 break; 74 #endif 75 default: 76 WARN_ON_ONCE(1); 77 break; 78 } 79 80 return sk; 81 } 82 83 static void nft_socket_eval(const struct nft_expr *expr, 84 struct nft_regs *regs, 85 const struct nft_pktinfo *pkt) 86 { 87 const struct nft_socket *priv = nft_expr_priv(expr); 88 struct sk_buff *skb = pkt->skb; 89 struct sock *sk = skb->sk; 90 u32 *dest = ®s->data[priv->dreg]; 91 92 if (sk && !net_eq(nft_net(pkt), sock_net(sk))) 93 sk = NULL; 94 95 if (!sk) 96 sk = nft_socket_do_lookup(pkt); 97 98 if (!sk) { 99 regs->verdict.code = NFT_BREAK; 100 return; 101 } 102 103 switch(priv->key) { 104 case NFT_SOCKET_TRANSPARENT: 105 nft_reg_store8(dest, inet_sk_transparent(sk)); 106 break; 107 case NFT_SOCKET_MARK: 108 if (sk_fullsock(sk)) { 109 *dest = sk->sk_mark; 110 } else { 111 regs->verdict.code = NFT_BREAK; 112 return; 113 } 114 break; 115 case NFT_SOCKET_WILDCARD: 116 if (!sk_fullsock(sk)) { 117 regs->verdict.code = NFT_BREAK; 118 return; 119 } 120 nft_socket_wildcard(pkt, regs, sk, dest); 121 break; 122 #ifdef CONFIG_SOCK_CGROUP_DATA 123 case NFT_SOCKET_CGROUPV2: 124 if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) { 125 regs->verdict.code = NFT_BREAK; 126 return; 127 } 128 break; 129 #endif 130 default: 131 WARN_ON(1); 132 regs->verdict.code = NFT_BREAK; 133 } 134 135 if (sk != skb->sk) 136 sock_gen_put(sk); 137 } 138 139 static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { 140 [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, 141 [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, 142 [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 }, 143 }; 144 145 static int nft_socket_init(const struct nft_ctx *ctx, 146 const struct nft_expr *expr, 147 const struct nlattr * const tb[]) 148 { 149 struct nft_socket *priv = nft_expr_priv(expr); 150 unsigned int len; 151 152 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) 153 return -EINVAL; 154 155 switch(ctx->family) { 156 case NFPROTO_IPV4: 157 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 158 case NFPROTO_IPV6: 159 #endif 160 case NFPROTO_INET: 161 break; 162 default: 163 return -EOPNOTSUPP; 164 } 165 166 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY])); 167 switch(priv->key) { 168 case NFT_SOCKET_TRANSPARENT: 169 case NFT_SOCKET_WILDCARD: 170 len = sizeof(u8); 171 break; 172 case NFT_SOCKET_MARK: 173 len = sizeof(u32); 174 break; 175 #ifdef CONFIG_CGROUPS 176 case NFT_SOCKET_CGROUPV2: { 177 unsigned int level; 178 179 if (!tb[NFTA_SOCKET_LEVEL]) 180 return -EINVAL; 181 182 level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL])); 183 if (level > 255) 184 return -EOPNOTSUPP; 185 186 priv->level = level; 187 len = sizeof(u64); 188 break; 189 } 190 #endif 191 default: 192 return -EOPNOTSUPP; 193 } 194 195 priv->len = len; 196 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, 197 NULL, NFT_DATA_VALUE, len); 198 } 199 200 static int nft_socket_dump(struct sk_buff *skb, 201 const struct nft_expr *expr) 202 { 203 const struct nft_socket *priv = nft_expr_priv(expr); 204 205 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) 206 return -1; 207 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) 208 return -1; 209 if (priv->key == NFT_SOCKET_CGROUPV2 && 210 nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level))) 211 return -1; 212 return 0; 213 } 214 215 static bool nft_socket_reduce(struct nft_regs_track *track, 216 const struct nft_expr *expr) 217 { 218 const struct nft_socket *priv = nft_expr_priv(expr); 219 const struct nft_socket *socket; 220 221 if (!nft_reg_track_cmp(track, expr, priv->dreg)) { 222 nft_reg_track_update(track, expr, priv->dreg, priv->len); 223 return false; 224 } 225 226 socket = nft_expr_priv(track->regs[priv->dreg].selector); 227 if (priv->key != socket->key || 228 priv->dreg != socket->dreg || 229 priv->level != socket->level) { 230 nft_reg_track_update(track, expr, priv->dreg, priv->len); 231 return false; 232 } 233 234 if (!track->regs[priv->dreg].bitwise) 235 return true; 236 237 return nft_expr_reduce_bitwise(track, expr); 238 } 239 240 static int nft_socket_validate(const struct nft_ctx *ctx, 241 const struct nft_expr *expr, 242 const struct nft_data **data) 243 { 244 return nft_chain_validate_hooks(ctx->chain, 245 (1 << NF_INET_PRE_ROUTING) | 246 (1 << NF_INET_LOCAL_IN) | 247 (1 << NF_INET_LOCAL_OUT)); 248 } 249 250 static struct nft_expr_type nft_socket_type; 251 static const struct nft_expr_ops nft_socket_ops = { 252 .type = &nft_socket_type, 253 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), 254 .eval = nft_socket_eval, 255 .init = nft_socket_init, 256 .dump = nft_socket_dump, 257 .validate = nft_socket_validate, 258 .reduce = nft_socket_reduce, 259 }; 260 261 static struct nft_expr_type nft_socket_type __read_mostly = { 262 .name = "socket", 263 .ops = &nft_socket_ops, 264 .policy = nft_socket_policy, 265 .maxattr = NFTA_SOCKET_MAX, 266 .owner = THIS_MODULE, 267 }; 268 269 static int __init nft_socket_module_init(void) 270 { 271 return nft_register_expr(&nft_socket_type); 272 } 273 274 static void __exit nft_socket_module_exit(void) 275 { 276 nft_unregister_expr(&nft_socket_type); 277 } 278 279 module_init(nft_socket_module_init); 280 module_exit(nft_socket_module_exit); 281 282 MODULE_LICENSE("GPL"); 283 MODULE_AUTHOR("Máté Eckl"); 284 MODULE_DESCRIPTION("nf_tables socket match module"); 285 MODULE_ALIAS_NFT_EXPR("socket"); 286