| 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 = pkt->in, *out = pkt->out; |
| 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 | *dest = 0; |
| 49 | *(__be16 *)dest = skb->protocol; |
| 50 | break; |
| 51 | case NFT_META_NFPROTO: |
| 52 | *dest = pkt->pf; |
| 53 | break; |
| 54 | case NFT_META_L4PROTO: |
| 55 | *dest = pkt->tprot; |
| 56 | break; |
| 57 | case NFT_META_PRIORITY: |
| 58 | *dest = skb->priority; |
| 59 | break; |
| 60 | case NFT_META_MARK: |
| 61 | *dest = skb->mark; |
| 62 | break; |
| 63 | case NFT_META_IIF: |
| 64 | if (in == NULL) |
| 65 | goto err; |
| 66 | *dest = in->ifindex; |
| 67 | break; |
| 68 | case NFT_META_OIF: |
| 69 | if (out == NULL) |
| 70 | goto err; |
| 71 | *dest = out->ifindex; |
| 72 | break; |
| 73 | case NFT_META_IIFNAME: |
| 74 | if (in == NULL) |
| 75 | goto err; |
| 76 | strncpy((char *)dest, in->name, IFNAMSIZ); |
| 77 | break; |
| 78 | case NFT_META_OIFNAME: |
| 79 | if (out == NULL) |
| 80 | goto err; |
| 81 | strncpy((char *)dest, out->name, IFNAMSIZ); |
| 82 | break; |
| 83 | case NFT_META_IIFTYPE: |
| 84 | if (in == NULL) |
| 85 | goto err; |
| 86 | *dest = 0; |
| 87 | *(u16 *)dest = in->type; |
| 88 | break; |
| 89 | case NFT_META_OIFTYPE: |
| 90 | if (out == NULL) |
| 91 | goto err; |
| 92 | *dest = 0; |
| 93 | *(u16 *)dest = out->type; |
| 94 | break; |
| 95 | case NFT_META_SKUID: |
| 96 | sk = skb_to_full_sk(skb); |
| 97 | if (!sk || !sk_fullsock(sk)) |
| 98 | goto err; |
| 99 | |
| 100 | read_lock_bh(&sk->sk_callback_lock); |
| 101 | if (sk->sk_socket == NULL || |
| 102 | sk->sk_socket->file == NULL) { |
| 103 | read_unlock_bh(&sk->sk_callback_lock); |
| 104 | goto err; |
| 105 | } |
| 106 | |
| 107 | *dest = from_kuid_munged(&init_user_ns, |
| 108 | sk->sk_socket->file->f_cred->fsuid); |
| 109 | read_unlock_bh(&sk->sk_callback_lock); |
| 110 | break; |
| 111 | case NFT_META_SKGID: |
| 112 | sk = skb_to_full_sk(skb); |
| 113 | if (!sk || !sk_fullsock(sk)) |
| 114 | goto err; |
| 115 | |
| 116 | read_lock_bh(&sk->sk_callback_lock); |
| 117 | if (sk->sk_socket == NULL || |
| 118 | sk->sk_socket->file == NULL) { |
| 119 | read_unlock_bh(&sk->sk_callback_lock); |
| 120 | goto err; |
| 121 | } |
| 122 | *dest = from_kgid_munged(&init_user_ns, |
| 123 | sk->sk_socket->file->f_cred->fsgid); |
| 124 | read_unlock_bh(&sk->sk_callback_lock); |
| 125 | break; |
| 126 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 127 | case NFT_META_RTCLASSID: { |
| 128 | const struct dst_entry *dst = skb_dst(skb); |
| 129 | |
| 130 | if (dst == NULL) |
| 131 | goto err; |
| 132 | *dest = dst->tclassid; |
| 133 | break; |
| 134 | } |
| 135 | #endif |
| 136 | #ifdef CONFIG_NETWORK_SECMARK |
| 137 | case NFT_META_SECMARK: |
| 138 | *dest = skb->secmark; |
| 139 | break; |
| 140 | #endif |
| 141 | case NFT_META_PKTTYPE: |
| 142 | if (skb->pkt_type != PACKET_LOOPBACK) { |
| 143 | *dest = skb->pkt_type; |
| 144 | break; |
| 145 | } |
| 146 | |
| 147 | switch (pkt->pf) { |
| 148 | case NFPROTO_IPV4: |
| 149 | if (ipv4_is_multicast(ip_hdr(skb)->daddr)) |
| 150 | *dest = PACKET_MULTICAST; |
| 151 | else |
| 152 | *dest = PACKET_BROADCAST; |
| 153 | break; |
| 154 | case NFPROTO_IPV6: |
| 155 | if (ipv6_hdr(skb)->daddr.s6_addr[0] == 0xFF) |
| 156 | *dest = PACKET_MULTICAST; |
| 157 | else |
| 158 | *dest = PACKET_BROADCAST; |
| 159 | break; |
| 160 | default: |
| 161 | WARN_ON(1); |
| 162 | goto err; |
| 163 | } |
| 164 | break; |
| 165 | case NFT_META_CPU: |
| 166 | *dest = raw_smp_processor_id(); |
| 167 | break; |
| 168 | case NFT_META_IIFGROUP: |
| 169 | if (in == NULL) |
| 170 | goto err; |
| 171 | *dest = in->group; |
| 172 | break; |
| 173 | case NFT_META_OIFGROUP: |
| 174 | if (out == NULL) |
| 175 | goto err; |
| 176 | *dest = out->group; |
| 177 | break; |
| 178 | #ifdef CONFIG_CGROUP_NET_CLASSID |
| 179 | case NFT_META_CGROUP: |
| 180 | sk = skb_to_full_sk(skb); |
| 181 | if (!sk || !sk_fullsock(sk)) |
| 182 | goto err; |
| 183 | *dest = sock_cgroup_classid(&sk->sk_cgrp_data); |
| 184 | break; |
| 185 | #endif |
| 186 | case NFT_META_PRANDOM: { |
| 187 | struct rnd_state *state = this_cpu_ptr(&nft_prandom_state); |
| 188 | *dest = prandom_u32_state(state); |
| 189 | break; |
| 190 | } |
| 191 | default: |
| 192 | WARN_ON(1); |
| 193 | goto err; |
| 194 | } |
| 195 | return; |
| 196 | |
| 197 | err: |
| 198 | regs->verdict.code = NFT_BREAK; |
| 199 | } |
| 200 | EXPORT_SYMBOL_GPL(nft_meta_get_eval); |
| 201 | |
| 202 | /* don't change or set _LOOPBACK, _USER, etc. */ |
| 203 | static bool pkt_type_ok(u32 p) |
| 204 | { |
| 205 | return p == PACKET_HOST || p == PACKET_BROADCAST || |
| 206 | p == PACKET_MULTICAST || p == PACKET_OTHERHOST; |
| 207 | } |
| 208 | |
| 209 | void nft_meta_set_eval(const struct nft_expr *expr, |
| 210 | struct nft_regs *regs, |
| 211 | const struct nft_pktinfo *pkt) |
| 212 | { |
| 213 | const struct nft_meta *meta = nft_expr_priv(expr); |
| 214 | struct sk_buff *skb = pkt->skb; |
| 215 | u32 value = regs->data[meta->sreg]; |
| 216 | |
| 217 | switch (meta->key) { |
| 218 | case NFT_META_MARK: |
| 219 | skb->mark = value; |
| 220 | break; |
| 221 | case NFT_META_PRIORITY: |
| 222 | skb->priority = value; |
| 223 | break; |
| 224 | case NFT_META_PKTTYPE: |
| 225 | if (skb->pkt_type != value && |
| 226 | pkt_type_ok(value) && pkt_type_ok(skb->pkt_type)) |
| 227 | skb->pkt_type = value; |
| 228 | break; |
| 229 | case NFT_META_NFTRACE: |
| 230 | skb->nf_trace = 1; |
| 231 | break; |
| 232 | default: |
| 233 | WARN_ON(1); |
| 234 | } |
| 235 | } |
| 236 | EXPORT_SYMBOL_GPL(nft_meta_set_eval); |
| 237 | |
| 238 | const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = { |
| 239 | [NFTA_META_DREG] = { .type = NLA_U32 }, |
| 240 | [NFTA_META_KEY] = { .type = NLA_U32 }, |
| 241 | [NFTA_META_SREG] = { .type = NLA_U32 }, |
| 242 | }; |
| 243 | EXPORT_SYMBOL_GPL(nft_meta_policy); |
| 244 | |
| 245 | int nft_meta_get_init(const struct nft_ctx *ctx, |
| 246 | const struct nft_expr *expr, |
| 247 | const struct nlattr * const tb[]) |
| 248 | { |
| 249 | struct nft_meta *priv = nft_expr_priv(expr); |
| 250 | unsigned int len; |
| 251 | |
| 252 | priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); |
| 253 | switch (priv->key) { |
| 254 | case NFT_META_PROTOCOL: |
| 255 | case NFT_META_IIFTYPE: |
| 256 | case NFT_META_OIFTYPE: |
| 257 | len = sizeof(u16); |
| 258 | break; |
| 259 | case NFT_META_NFPROTO: |
| 260 | case NFT_META_L4PROTO: |
| 261 | case NFT_META_LEN: |
| 262 | case NFT_META_PRIORITY: |
| 263 | case NFT_META_MARK: |
| 264 | case NFT_META_IIF: |
| 265 | case NFT_META_OIF: |
| 266 | case NFT_META_SKUID: |
| 267 | case NFT_META_SKGID: |
| 268 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 269 | case NFT_META_RTCLASSID: |
| 270 | #endif |
| 271 | #ifdef CONFIG_NETWORK_SECMARK |
| 272 | case NFT_META_SECMARK: |
| 273 | #endif |
| 274 | case NFT_META_PKTTYPE: |
| 275 | case NFT_META_CPU: |
| 276 | case NFT_META_IIFGROUP: |
| 277 | case NFT_META_OIFGROUP: |
| 278 | #ifdef CONFIG_CGROUP_NET_CLASSID |
| 279 | case NFT_META_CGROUP: |
| 280 | #endif |
| 281 | len = sizeof(u32); |
| 282 | break; |
| 283 | case NFT_META_IIFNAME: |
| 284 | case NFT_META_OIFNAME: |
| 285 | len = IFNAMSIZ; |
| 286 | break; |
| 287 | case NFT_META_PRANDOM: |
| 288 | prandom_init_once(&nft_prandom_state); |
| 289 | len = sizeof(u32); |
| 290 | break; |
| 291 | default: |
| 292 | return -EOPNOTSUPP; |
| 293 | } |
| 294 | |
| 295 | priv->dreg = nft_parse_register(tb[NFTA_META_DREG]); |
| 296 | return nft_validate_register_store(ctx, priv->dreg, NULL, |
| 297 | NFT_DATA_VALUE, len); |
| 298 | } |
| 299 | EXPORT_SYMBOL_GPL(nft_meta_get_init); |
| 300 | |
| 301 | static int nft_meta_set_init_pkttype(const struct nft_ctx *ctx) |
| 302 | { |
| 303 | unsigned int hooks; |
| 304 | |
| 305 | switch (ctx->afi->family) { |
| 306 | case NFPROTO_BRIDGE: |
| 307 | hooks = 1 << NF_BR_PRE_ROUTING; |
| 308 | break; |
| 309 | case NFPROTO_NETDEV: |
| 310 | hooks = 1 << NF_NETDEV_INGRESS; |
| 311 | break; |
| 312 | default: |
| 313 | return -EOPNOTSUPP; |
| 314 | } |
| 315 | |
| 316 | return nft_chain_validate_hooks(ctx->chain, hooks); |
| 317 | } |
| 318 | |
| 319 | int nft_meta_set_init(const struct nft_ctx *ctx, |
| 320 | const struct nft_expr *expr, |
| 321 | const struct nlattr * const tb[]) |
| 322 | { |
| 323 | struct nft_meta *priv = nft_expr_priv(expr); |
| 324 | unsigned int len; |
| 325 | int err; |
| 326 | |
| 327 | priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); |
| 328 | switch (priv->key) { |
| 329 | case NFT_META_MARK: |
| 330 | case NFT_META_PRIORITY: |
| 331 | len = sizeof(u32); |
| 332 | break; |
| 333 | case NFT_META_NFTRACE: |
| 334 | len = sizeof(u8); |
| 335 | break; |
| 336 | case NFT_META_PKTTYPE: |
| 337 | err = nft_meta_set_init_pkttype(ctx); |
| 338 | if (err) |
| 339 | return err; |
| 340 | len = sizeof(u8); |
| 341 | break; |
| 342 | default: |
| 343 | return -EOPNOTSUPP; |
| 344 | } |
| 345 | |
| 346 | priv->sreg = nft_parse_register(tb[NFTA_META_SREG]); |
| 347 | err = nft_validate_register_load(priv->sreg, len); |
| 348 | if (err < 0) |
| 349 | return err; |
| 350 | |
| 351 | if (priv->key == NFT_META_NFTRACE) |
| 352 | static_branch_inc(&nft_trace_enabled); |
| 353 | |
| 354 | return 0; |
| 355 | } |
| 356 | EXPORT_SYMBOL_GPL(nft_meta_set_init); |
| 357 | |
| 358 | int nft_meta_get_dump(struct sk_buff *skb, |
| 359 | const struct nft_expr *expr) |
| 360 | { |
| 361 | const struct nft_meta *priv = nft_expr_priv(expr); |
| 362 | |
| 363 | if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) |
| 364 | goto nla_put_failure; |
| 365 | if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg)) |
| 366 | goto nla_put_failure; |
| 367 | return 0; |
| 368 | |
| 369 | nla_put_failure: |
| 370 | return -1; |
| 371 | } |
| 372 | EXPORT_SYMBOL_GPL(nft_meta_get_dump); |
| 373 | |
| 374 | int nft_meta_set_dump(struct sk_buff *skb, |
| 375 | const struct nft_expr *expr) |
| 376 | { |
| 377 | const struct nft_meta *priv = nft_expr_priv(expr); |
| 378 | |
| 379 | if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) |
| 380 | goto nla_put_failure; |
| 381 | if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg)) |
| 382 | goto nla_put_failure; |
| 383 | |
| 384 | return 0; |
| 385 | |
| 386 | nla_put_failure: |
| 387 | return -1; |
| 388 | } |
| 389 | EXPORT_SYMBOL_GPL(nft_meta_set_dump); |
| 390 | |
| 391 | void nft_meta_set_destroy(const struct nft_ctx *ctx, |
| 392 | const struct nft_expr *expr) |
| 393 | { |
| 394 | const struct nft_meta *priv = nft_expr_priv(expr); |
| 395 | |
| 396 | if (priv->key == NFT_META_NFTRACE) |
| 397 | static_branch_dec(&nft_trace_enabled); |
| 398 | } |
| 399 | EXPORT_SYMBOL_GPL(nft_meta_set_destroy); |
| 400 | |
| 401 | static struct nft_expr_type nft_meta_type; |
| 402 | static const struct nft_expr_ops nft_meta_get_ops = { |
| 403 | .type = &nft_meta_type, |
| 404 | .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), |
| 405 | .eval = nft_meta_get_eval, |
| 406 | .init = nft_meta_get_init, |
| 407 | .dump = nft_meta_get_dump, |
| 408 | }; |
| 409 | |
| 410 | static const struct nft_expr_ops nft_meta_set_ops = { |
| 411 | .type = &nft_meta_type, |
| 412 | .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), |
| 413 | .eval = nft_meta_set_eval, |
| 414 | .init = nft_meta_set_init, |
| 415 | .destroy = nft_meta_set_destroy, |
| 416 | .dump = nft_meta_set_dump, |
| 417 | }; |
| 418 | |
| 419 | static const struct nft_expr_ops * |
| 420 | nft_meta_select_ops(const struct nft_ctx *ctx, |
| 421 | const struct nlattr * const tb[]) |
| 422 | { |
| 423 | if (tb[NFTA_META_KEY] == NULL) |
| 424 | return ERR_PTR(-EINVAL); |
| 425 | |
| 426 | if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG]) |
| 427 | return ERR_PTR(-EINVAL); |
| 428 | |
| 429 | if (tb[NFTA_META_DREG]) |
| 430 | return &nft_meta_get_ops; |
| 431 | |
| 432 | if (tb[NFTA_META_SREG]) |
| 433 | return &nft_meta_set_ops; |
| 434 | |
| 435 | return ERR_PTR(-EINVAL); |
| 436 | } |
| 437 | |
| 438 | static struct nft_expr_type nft_meta_type __read_mostly = { |
| 439 | .name = "meta", |
| 440 | .select_ops = &nft_meta_select_ops, |
| 441 | .policy = nft_meta_policy, |
| 442 | .maxattr = NFTA_META_MAX, |
| 443 | .owner = THIS_MODULE, |
| 444 | }; |
| 445 | |
| 446 | static int __init nft_meta_module_init(void) |
| 447 | { |
| 448 | return nft_register_expr(&nft_meta_type); |
| 449 | } |
| 450 | |
| 451 | static void __exit nft_meta_module_exit(void) |
| 452 | { |
| 453 | nft_unregister_expr(&nft_meta_type); |
| 454 | } |
| 455 | |
| 456 | module_init(nft_meta_module_init); |
| 457 | module_exit(nft_meta_module_exit); |
| 458 | |
| 459 | MODULE_LICENSE("GPL"); |
| 460 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 461 | MODULE_ALIAS_NFT_EXPR("meta"); |