1 /* 2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * Development of this code funded by Astaro AG (http://www.astaro.com/) 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/netlink.h> 15 #include <linux/netfilter.h> 16 #include <linux/netfilter/nf_tables.h> 17 #include <linux/in.h> 18 #include <linux/ip.h> 19 #include <linux/ipv6.h> 20 #include <linux/smp.h> 21 #include <linux/static_key.h> 22 #include <net/dst.h> 23 #include <net/sock.h> 24 #include <net/tcp_states.h> /* for TCP_TIME_WAIT */ 25 #include <net/netfilter/nf_tables.h> 26 #include <net/netfilter/nf_tables_core.h> 27 #include <net/netfilter/nft_meta.h> 28 29 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */ 30 31 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state); 32 33 void nft_meta_get_eval(const struct nft_expr *expr, 34 struct nft_regs *regs, 35 const struct nft_pktinfo *pkt) 36 { 37 const struct nft_meta *priv = nft_expr_priv(expr); 38 const struct sk_buff *skb = pkt->skb; 39 const struct net_device *in = nft_in(pkt), *out = nft_out(pkt); 40 struct sock *sk; 41 u32 *dest = ®s->data[priv->dreg]; 42 43 switch (priv->key) { 44 case NFT_META_LEN: 45 *dest = skb->len; 46 break; 47 case NFT_META_PROTOCOL: 48 nft_reg_store16(dest, (__force u16)skb->protocol); 49 break; 50 case NFT_META_NFPROTO: 51 nft_reg_store8(dest, nft_pf(pkt)); 52 break; 53 case NFT_META_L4PROTO: 54 if (!pkt->tprot_set) 55 goto err; 56 nft_reg_store8(dest, pkt->tprot); 57 break; 58 case NFT_META_PRIORITY: 59 *dest = skb->priority; 60 break; 61 case NFT_META_MARK: 62 *dest = skb->mark; 63 break; 64 case NFT_META_IIF: 65 if (in == NULL) 66 goto err; 67 *dest = in->ifindex; 68 break; 69 case NFT_META_OIF: 70 if (out == NULL) 71 goto err; 72 *dest = out->ifindex; 73 break; 74 case NFT_META_IIFNAME: 75 if (in == NULL) 76 goto err; 77 strncpy((char *)dest, in->name, IFNAMSIZ); 78 break; 79 case NFT_META_OIFNAME: 80 if (out == NULL) 81 goto err; 82 strncpy((char *)dest, out->name, IFNAMSIZ); 83 break; 84 case NFT_META_IIFTYPE: 85 if (in == NULL) 86 goto err; 87 nft_reg_store16(dest, in->type); 88 break; 89 case NFT_META_OIFTYPE: 90 if (out == NULL) 91 goto err; 92 nft_reg_store16(dest, out->type); 93 break; 94 case NFT_META_SKUID: 95 sk = skb_to_full_sk(skb); 96 if (!sk || !sk_fullsock(sk)) 97 goto err; 98 99 read_lock_bh(&sk->sk_callback_lock); 100 if (sk->sk_socket == NULL || 101 sk->sk_socket->file == NULL) { 102 read_unlock_bh(&sk->sk_callback_lock); 103 goto err; 104 } 105 106 *dest = from_kuid_munged(&init_user_ns, 107 sk->sk_socket->file->f_cred->fsuid); 108 read_unlock_bh(&sk->sk_callback_lock); 109 break; 110 case NFT_META_SKGID: 111 sk = skb_to_full_sk(skb); 112 if (!sk || !sk_fullsock(sk)) 113 goto err; 114 115 read_lock_bh(&sk->sk_callback_lock); 116 if (sk->sk_socket == NULL || 117 sk->sk_socket->file == NULL) { 118 read_unlock_bh(&sk->sk_callback_lock); 119 goto err; 120 } 121 *dest = from_kgid_munged(&init_user_ns, 122 sk->sk_socket->file->f_cred->fsgid); 123 read_unlock_bh(&sk->sk_callback_lock); 124 break; 125 #ifdef CONFIG_IP_ROUTE_CLASSID 126 case NFT_META_RTCLASSID: { 127 const struct dst_entry *dst = skb_dst(skb); 128 129 if (dst == NULL) 130 goto err; 131 *dest = dst->tclassid; 132 break; 133 } 134 #endif 135 #ifdef CONFIG_NETWORK_SECMARK 136 case NFT_META_SECMARK: 137 *dest = skb->secmark; 138 break; 139 #endif 140 case NFT_META_PKTTYPE: 141 if (skb->pkt_type != PACKET_LOOPBACK) { 142 nft_reg_store8(dest, skb->pkt_type); 143 break; 144 } 145 146 switch (nft_pf(pkt)) { 147 case NFPROTO_IPV4: 148 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 149 nft_reg_store8(dest, PACKET_MULTICAST); 150 else 151 nft_reg_store8(dest, PACKET_BROADCAST); 152 break; 153 case NFPROTO_IPV6: 154 nft_reg_store8(dest, PACKET_MULTICAST); 155 break; 156 case NFPROTO_NETDEV: 157 switch (skb->protocol) { 158 case htons(ETH_P_IP): { 159 int noff = skb_network_offset(skb); 160 struct iphdr *iph, _iph; 161 162 iph = skb_header_pointer(skb, noff, 163 sizeof(_iph), &_iph); 164 if (!iph) 165 goto err; 166 167 if (ipv4_is_multicast(iph->daddr)) 168 nft_reg_store8(dest, PACKET_MULTICAST); 169 else 170 nft_reg_store8(dest, PACKET_BROADCAST); 171 172 break; 173 } 174 case htons(ETH_P_IPV6): 175 nft_reg_store8(dest, PACKET_MULTICAST); 176 break; 177 default: 178 WARN_ON_ONCE(1); 179 goto err; 180 } 181 break; 182 default: 183 WARN_ON_ONCE(1); 184 goto err; 185 } 186 break; 187 case NFT_META_CPU: 188 *dest = raw_smp_processor_id(); 189 break; 190 case NFT_META_IIFGROUP: 191 if (in == NULL) 192 goto err; 193 *dest = in->group; 194 break; 195 case NFT_META_OIFGROUP: 196 if (out == NULL) 197 goto err; 198 *dest = out->group; 199 break; 200 #ifdef CONFIG_CGROUP_NET_CLASSID 201 case NFT_META_CGROUP: 202 sk = skb_to_full_sk(skb); 203 if (!sk || !sk_fullsock(sk)) 204 goto err; 205 *dest = sock_cgroup_classid(&sk->sk_cgrp_data); 206 break; 207 #endif 208 case NFT_META_PRANDOM: { 209 struct rnd_state *state = this_cpu_ptr(&nft_prandom_state); 210 *dest = prandom_u32_state(state); 211 break; 212 } 213 default: 214 WARN_ON(1); 215 goto err; 216 } 217 return; 218 219 err: 220 regs->verdict.code = NFT_BREAK; 221 } 222 EXPORT_SYMBOL_GPL(nft_meta_get_eval); 223 224 void nft_meta_set_eval(const struct nft_expr *expr, 225 struct nft_regs *regs, 226 const struct nft_pktinfo *pkt) 227 { 228 const struct nft_meta *meta = nft_expr_priv(expr); 229 struct sk_buff *skb = pkt->skb; 230 u32 *sreg = ®s->data[meta->sreg]; 231 u32 value = *sreg; 232 u8 pkt_type; 233 234 switch (meta->key) { 235 case NFT_META_MARK: 236 skb->mark = value; 237 break; 238 case NFT_META_PRIORITY: 239 skb->priority = value; 240 break; 241 case NFT_META_PKTTYPE: 242 pkt_type = nft_reg_load8(sreg); 243 244 if (skb->pkt_type != pkt_type && 245 skb_pkt_type_ok(pkt_type) && 246 skb_pkt_type_ok(skb->pkt_type)) 247 skb->pkt_type = pkt_type; 248 break; 249 case NFT_META_NFTRACE: 250 skb->nf_trace = !!value; 251 break; 252 default: 253 WARN_ON(1); 254 } 255 } 256 EXPORT_SYMBOL_GPL(nft_meta_set_eval); 257 258 const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = { 259 [NFTA_META_DREG] = { .type = NLA_U32 }, 260 [NFTA_META_KEY] = { .type = NLA_U32 }, 261 [NFTA_META_SREG] = { .type = NLA_U32 }, 262 }; 263 EXPORT_SYMBOL_GPL(nft_meta_policy); 264 265 int nft_meta_get_init(const struct nft_ctx *ctx, 266 const struct nft_expr *expr, 267 const struct nlattr * const tb[]) 268 { 269 struct nft_meta *priv = nft_expr_priv(expr); 270 unsigned int len; 271 272 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); 273 switch (priv->key) { 274 case NFT_META_PROTOCOL: 275 case NFT_META_IIFTYPE: 276 case NFT_META_OIFTYPE: 277 len = sizeof(u16); 278 break; 279 case NFT_META_NFPROTO: 280 case NFT_META_L4PROTO: 281 case NFT_META_LEN: 282 case NFT_META_PRIORITY: 283 case NFT_META_MARK: 284 case NFT_META_IIF: 285 case NFT_META_OIF: 286 case NFT_META_SKUID: 287 case NFT_META_SKGID: 288 #ifdef CONFIG_IP_ROUTE_CLASSID 289 case NFT_META_RTCLASSID: 290 #endif 291 #ifdef CONFIG_NETWORK_SECMARK 292 case NFT_META_SECMARK: 293 #endif 294 case NFT_META_PKTTYPE: 295 case NFT_META_CPU: 296 case NFT_META_IIFGROUP: 297 case NFT_META_OIFGROUP: 298 #ifdef CONFIG_CGROUP_NET_CLASSID 299 case NFT_META_CGROUP: 300 #endif 301 len = sizeof(u32); 302 break; 303 case NFT_META_IIFNAME: 304 case NFT_META_OIFNAME: 305 len = IFNAMSIZ; 306 break; 307 case NFT_META_PRANDOM: 308 prandom_init_once(&nft_prandom_state); 309 len = sizeof(u32); 310 break; 311 default: 312 return -EOPNOTSUPP; 313 } 314 315 priv->dreg = nft_parse_register(tb[NFTA_META_DREG]); 316 return nft_validate_register_store(ctx, priv->dreg, NULL, 317 NFT_DATA_VALUE, len); 318 } 319 EXPORT_SYMBOL_GPL(nft_meta_get_init); 320 321 int nft_meta_set_validate(const struct nft_ctx *ctx, 322 const struct nft_expr *expr, 323 const struct nft_data **data) 324 { 325 struct nft_meta *priv = nft_expr_priv(expr); 326 unsigned int hooks; 327 328 if (priv->key != NFT_META_PKTTYPE) 329 return 0; 330 331 switch (ctx->afi->family) { 332 case NFPROTO_BRIDGE: 333 hooks = 1 << NF_BR_PRE_ROUTING; 334 break; 335 case NFPROTO_NETDEV: 336 hooks = 1 << NF_NETDEV_INGRESS; 337 break; 338 case NFPROTO_IPV4: 339 case NFPROTO_IPV6: 340 case NFPROTO_INET: 341 hooks = 1 << NF_INET_PRE_ROUTING; 342 break; 343 default: 344 return -EOPNOTSUPP; 345 } 346 347 return nft_chain_validate_hooks(ctx->chain, hooks); 348 } 349 EXPORT_SYMBOL_GPL(nft_meta_set_validate); 350 351 int nft_meta_set_init(const struct nft_ctx *ctx, 352 const struct nft_expr *expr, 353 const struct nlattr * const tb[]) 354 { 355 struct nft_meta *priv = nft_expr_priv(expr); 356 unsigned int len; 357 int err; 358 359 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); 360 switch (priv->key) { 361 case NFT_META_MARK: 362 case NFT_META_PRIORITY: 363 len = sizeof(u32); 364 break; 365 case NFT_META_NFTRACE: 366 len = sizeof(u8); 367 break; 368 case NFT_META_PKTTYPE: 369 len = sizeof(u8); 370 break; 371 default: 372 return -EOPNOTSUPP; 373 } 374 375 priv->sreg = nft_parse_register(tb[NFTA_META_SREG]); 376 err = nft_validate_register_load(priv->sreg, len); 377 if (err < 0) 378 return err; 379 380 if (priv->key == NFT_META_NFTRACE) 381 static_branch_inc(&nft_trace_enabled); 382 383 return 0; 384 } 385 EXPORT_SYMBOL_GPL(nft_meta_set_init); 386 387 int nft_meta_get_dump(struct sk_buff *skb, 388 const struct nft_expr *expr) 389 { 390 const struct nft_meta *priv = nft_expr_priv(expr); 391 392 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) 393 goto nla_put_failure; 394 if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg)) 395 goto nla_put_failure; 396 return 0; 397 398 nla_put_failure: 399 return -1; 400 } 401 EXPORT_SYMBOL_GPL(nft_meta_get_dump); 402 403 int nft_meta_set_dump(struct sk_buff *skb, 404 const struct nft_expr *expr) 405 { 406 const struct nft_meta *priv = nft_expr_priv(expr); 407 408 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) 409 goto nla_put_failure; 410 if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg)) 411 goto nla_put_failure; 412 413 return 0; 414 415 nla_put_failure: 416 return -1; 417 } 418 EXPORT_SYMBOL_GPL(nft_meta_set_dump); 419 420 void nft_meta_set_destroy(const struct nft_ctx *ctx, 421 const struct nft_expr *expr) 422 { 423 const struct nft_meta *priv = nft_expr_priv(expr); 424 425 if (priv->key == NFT_META_NFTRACE) 426 static_branch_dec(&nft_trace_enabled); 427 } 428 EXPORT_SYMBOL_GPL(nft_meta_set_destroy); 429 430 static struct nft_expr_type nft_meta_type; 431 static const struct nft_expr_ops nft_meta_get_ops = { 432 .type = &nft_meta_type, 433 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 434 .eval = nft_meta_get_eval, 435 .init = nft_meta_get_init, 436 .dump = nft_meta_get_dump, 437 }; 438 439 static const struct nft_expr_ops nft_meta_set_ops = { 440 .type = &nft_meta_type, 441 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 442 .eval = nft_meta_set_eval, 443 .init = nft_meta_set_init, 444 .destroy = nft_meta_set_destroy, 445 .dump = nft_meta_set_dump, 446 .validate = nft_meta_set_validate, 447 }; 448 449 static const struct nft_expr_ops * 450 nft_meta_select_ops(const struct nft_ctx *ctx, 451 const struct nlattr * const tb[]) 452 { 453 if (tb[NFTA_META_KEY] == NULL) 454 return ERR_PTR(-EINVAL); 455 456 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG]) 457 return ERR_PTR(-EINVAL); 458 459 if (tb[NFTA_META_DREG]) 460 return &nft_meta_get_ops; 461 462 if (tb[NFTA_META_SREG]) 463 return &nft_meta_set_ops; 464 465 return ERR_PTR(-EINVAL); 466 } 467 468 static struct nft_expr_type nft_meta_type __read_mostly = { 469 .name = "meta", 470 .select_ops = nft_meta_select_ops, 471 .policy = nft_meta_policy, 472 .maxattr = NFTA_META_MAX, 473 .owner = THIS_MODULE, 474 }; 475 476 static int __init nft_meta_module_init(void) 477 { 478 return nft_register_expr(&nft_meta_type); 479 } 480 481 static void __exit nft_meta_module_exit(void) 482 { 483 nft_unregister_expr(&nft_meta_type); 484 } 485 486 module_init(nft_meta_module_init); 487 module_exit(nft_meta_module_exit); 488 489 MODULE_LICENSE("GPL"); 490 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 491 MODULE_ALIAS_NFT_EXPR("meta"); 492