1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> 4 * Copyright (c) 2014 Intel Corporation 5 * Author: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com> 6 * 7 * Development of this code funded by Astaro AG (http://www.astaro.com/) 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/netlink.h> 12 #include <linux/netfilter.h> 13 #include <linux/netfilter/nf_tables.h> 14 #include <linux/in.h> 15 #include <linux/ip.h> 16 #include <linux/ipv6.h> 17 #include <linux/smp.h> 18 #include <linux/static_key.h> 19 #include <net/dst.h> 20 #include <net/sock.h> 21 #include <net/tcp_states.h> /* for TCP_TIME_WAIT */ 22 #include <net/netfilter/nf_tables.h> 23 #include <net/netfilter/nf_tables_core.h> 24 #include <net/netfilter/nft_meta.h> 25 #include <net/netfilter/nf_tables_offload.h> 26 27 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */ 28 29 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state); 30 31 void nft_meta_get_eval(const struct nft_expr *expr, 32 struct nft_regs *regs, 33 const struct nft_pktinfo *pkt) 34 { 35 const struct nft_meta *priv = nft_expr_priv(expr); 36 const struct sk_buff *skb = pkt->skb; 37 const struct net_device *in = nft_in(pkt), *out = nft_out(pkt); 38 struct sock *sk; 39 u32 *dest = ®s->data[priv->dreg]; 40 41 switch (priv->key) { 42 case NFT_META_LEN: 43 *dest = skb->len; 44 break; 45 case NFT_META_PROTOCOL: 46 nft_reg_store16(dest, (__force u16)skb->protocol); 47 break; 48 case NFT_META_NFPROTO: 49 nft_reg_store8(dest, nft_pf(pkt)); 50 break; 51 case NFT_META_L4PROTO: 52 if (!pkt->tprot_set) 53 goto err; 54 nft_reg_store8(dest, pkt->tprot); 55 break; 56 case NFT_META_PRIORITY: 57 *dest = skb->priority; 58 break; 59 case NFT_META_MARK: 60 *dest = skb->mark; 61 break; 62 case NFT_META_IIF: 63 if (in == NULL) 64 goto err; 65 *dest = in->ifindex; 66 break; 67 case NFT_META_OIF: 68 if (out == NULL) 69 goto err; 70 *dest = out->ifindex; 71 break; 72 case NFT_META_IIFNAME: 73 if (in == NULL) 74 goto err; 75 strncpy((char *)dest, in->name, IFNAMSIZ); 76 break; 77 case NFT_META_OIFNAME: 78 if (out == NULL) 79 goto err; 80 strncpy((char *)dest, out->name, IFNAMSIZ); 81 break; 82 case NFT_META_IIFTYPE: 83 if (in == NULL) 84 goto err; 85 nft_reg_store16(dest, in->type); 86 break; 87 case NFT_META_OIFTYPE: 88 if (out == NULL) 89 goto err; 90 nft_reg_store16(dest, out->type); 91 break; 92 case NFT_META_SKUID: 93 sk = skb_to_full_sk(skb); 94 if (!sk || !sk_fullsock(sk) || 95 !net_eq(nft_net(pkt), sock_net(sk))) 96 goto err; 97 98 read_lock_bh(&sk->sk_callback_lock); 99 if (sk->sk_socket == NULL || 100 sk->sk_socket->file == NULL) { 101 read_unlock_bh(&sk->sk_callback_lock); 102 goto err; 103 } 104 105 *dest = from_kuid_munged(&init_user_ns, 106 sk->sk_socket->file->f_cred->fsuid); 107 read_unlock_bh(&sk->sk_callback_lock); 108 break; 109 case NFT_META_SKGID: 110 sk = skb_to_full_sk(skb); 111 if (!sk || !sk_fullsock(sk) || 112 !net_eq(nft_net(pkt), sock_net(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 !net_eq(nft_net(pkt), sock_net(sk))) 205 goto err; 206 *dest = sock_cgroup_classid(&sk->sk_cgrp_data); 207 break; 208 #endif 209 case NFT_META_PRANDOM: { 210 struct rnd_state *state = this_cpu_ptr(&nft_prandom_state); 211 *dest = prandom_u32_state(state); 212 break; 213 } 214 #ifdef CONFIG_XFRM 215 case NFT_META_SECPATH: 216 nft_reg_store8(dest, secpath_exists(skb)); 217 break; 218 #endif 219 case NFT_META_IIFKIND: 220 if (in == NULL || in->rtnl_link_ops == NULL) 221 goto err; 222 strncpy((char *)dest, in->rtnl_link_ops->kind, IFNAMSIZ); 223 break; 224 case NFT_META_OIFKIND: 225 if (out == NULL || out->rtnl_link_ops == NULL) 226 goto err; 227 strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ); 228 break; 229 default: 230 WARN_ON(1); 231 goto err; 232 } 233 return; 234 235 err: 236 regs->verdict.code = NFT_BREAK; 237 } 238 EXPORT_SYMBOL_GPL(nft_meta_get_eval); 239 240 void nft_meta_set_eval(const struct nft_expr *expr, 241 struct nft_regs *regs, 242 const struct nft_pktinfo *pkt) 243 { 244 const struct nft_meta *meta = nft_expr_priv(expr); 245 struct sk_buff *skb = pkt->skb; 246 u32 *sreg = ®s->data[meta->sreg]; 247 u32 value = *sreg; 248 u8 value8; 249 250 switch (meta->key) { 251 case NFT_META_MARK: 252 skb->mark = value; 253 break; 254 case NFT_META_PRIORITY: 255 skb->priority = value; 256 break; 257 case NFT_META_PKTTYPE: 258 value8 = nft_reg_load8(sreg); 259 260 if (skb->pkt_type != value8 && 261 skb_pkt_type_ok(value8) && 262 skb_pkt_type_ok(skb->pkt_type)) 263 skb->pkt_type = value8; 264 break; 265 case NFT_META_NFTRACE: 266 value8 = nft_reg_load8(sreg); 267 268 skb->nf_trace = !!value8; 269 break; 270 #ifdef CONFIG_NETWORK_SECMARK 271 case NFT_META_SECMARK: 272 skb->secmark = value; 273 break; 274 #endif 275 default: 276 WARN_ON(1); 277 } 278 } 279 EXPORT_SYMBOL_GPL(nft_meta_set_eval); 280 281 const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = { 282 [NFTA_META_DREG] = { .type = NLA_U32 }, 283 [NFTA_META_KEY] = { .type = NLA_U32 }, 284 [NFTA_META_SREG] = { .type = NLA_U32 }, 285 }; 286 EXPORT_SYMBOL_GPL(nft_meta_policy); 287 288 int nft_meta_get_init(const struct nft_ctx *ctx, 289 const struct nft_expr *expr, 290 const struct nlattr * const tb[]) 291 { 292 struct nft_meta *priv = nft_expr_priv(expr); 293 unsigned int len; 294 295 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); 296 switch (priv->key) { 297 case NFT_META_PROTOCOL: 298 case NFT_META_IIFTYPE: 299 case NFT_META_OIFTYPE: 300 len = sizeof(u16); 301 break; 302 case NFT_META_NFPROTO: 303 case NFT_META_L4PROTO: 304 case NFT_META_LEN: 305 case NFT_META_PRIORITY: 306 case NFT_META_MARK: 307 case NFT_META_IIF: 308 case NFT_META_OIF: 309 case NFT_META_SKUID: 310 case NFT_META_SKGID: 311 #ifdef CONFIG_IP_ROUTE_CLASSID 312 case NFT_META_RTCLASSID: 313 #endif 314 #ifdef CONFIG_NETWORK_SECMARK 315 case NFT_META_SECMARK: 316 #endif 317 case NFT_META_PKTTYPE: 318 case NFT_META_CPU: 319 case NFT_META_IIFGROUP: 320 case NFT_META_OIFGROUP: 321 #ifdef CONFIG_CGROUP_NET_CLASSID 322 case NFT_META_CGROUP: 323 #endif 324 len = sizeof(u32); 325 break; 326 case NFT_META_IIFNAME: 327 case NFT_META_OIFNAME: 328 case NFT_META_IIFKIND: 329 case NFT_META_OIFKIND: 330 len = IFNAMSIZ; 331 break; 332 case NFT_META_PRANDOM: 333 prandom_init_once(&nft_prandom_state); 334 len = sizeof(u32); 335 break; 336 #ifdef CONFIG_XFRM 337 case NFT_META_SECPATH: 338 len = sizeof(u8); 339 break; 340 #endif 341 default: 342 return -EOPNOTSUPP; 343 } 344 345 priv->dreg = nft_parse_register(tb[NFTA_META_DREG]); 346 return nft_validate_register_store(ctx, priv->dreg, NULL, 347 NFT_DATA_VALUE, len); 348 } 349 EXPORT_SYMBOL_GPL(nft_meta_get_init); 350 351 static int nft_meta_get_validate(const struct nft_ctx *ctx, 352 const struct nft_expr *expr, 353 const struct nft_data **data) 354 { 355 #ifdef CONFIG_XFRM 356 const struct nft_meta *priv = nft_expr_priv(expr); 357 unsigned int hooks; 358 359 if (priv->key != NFT_META_SECPATH) 360 return 0; 361 362 switch (ctx->family) { 363 case NFPROTO_NETDEV: 364 hooks = 1 << NF_NETDEV_INGRESS; 365 break; 366 case NFPROTO_IPV4: 367 case NFPROTO_IPV6: 368 case NFPROTO_INET: 369 hooks = (1 << NF_INET_PRE_ROUTING) | 370 (1 << NF_INET_LOCAL_IN) | 371 (1 << NF_INET_FORWARD); 372 break; 373 default: 374 return -EOPNOTSUPP; 375 } 376 377 return nft_chain_validate_hooks(ctx->chain, hooks); 378 #else 379 return 0; 380 #endif 381 } 382 383 int nft_meta_set_validate(const struct nft_ctx *ctx, 384 const struct nft_expr *expr, 385 const struct nft_data **data) 386 { 387 struct nft_meta *priv = nft_expr_priv(expr); 388 unsigned int hooks; 389 390 if (priv->key != NFT_META_PKTTYPE) 391 return 0; 392 393 switch (ctx->family) { 394 case NFPROTO_BRIDGE: 395 hooks = 1 << NF_BR_PRE_ROUTING; 396 break; 397 case NFPROTO_NETDEV: 398 hooks = 1 << NF_NETDEV_INGRESS; 399 break; 400 case NFPROTO_IPV4: 401 case NFPROTO_IPV6: 402 case NFPROTO_INET: 403 hooks = 1 << NF_INET_PRE_ROUTING; 404 break; 405 default: 406 return -EOPNOTSUPP; 407 } 408 409 return nft_chain_validate_hooks(ctx->chain, hooks); 410 } 411 EXPORT_SYMBOL_GPL(nft_meta_set_validate); 412 413 int nft_meta_set_init(const struct nft_ctx *ctx, 414 const struct nft_expr *expr, 415 const struct nlattr * const tb[]) 416 { 417 struct nft_meta *priv = nft_expr_priv(expr); 418 unsigned int len; 419 int err; 420 421 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); 422 switch (priv->key) { 423 case NFT_META_MARK: 424 case NFT_META_PRIORITY: 425 #ifdef CONFIG_NETWORK_SECMARK 426 case NFT_META_SECMARK: 427 #endif 428 len = sizeof(u32); 429 break; 430 case NFT_META_NFTRACE: 431 len = sizeof(u8); 432 break; 433 case NFT_META_PKTTYPE: 434 len = sizeof(u8); 435 break; 436 default: 437 return -EOPNOTSUPP; 438 } 439 440 priv->sreg = nft_parse_register(tb[NFTA_META_SREG]); 441 err = nft_validate_register_load(priv->sreg, len); 442 if (err < 0) 443 return err; 444 445 if (priv->key == NFT_META_NFTRACE) 446 static_branch_inc(&nft_trace_enabled); 447 448 return 0; 449 } 450 EXPORT_SYMBOL_GPL(nft_meta_set_init); 451 452 int nft_meta_get_dump(struct sk_buff *skb, 453 const struct nft_expr *expr) 454 { 455 const struct nft_meta *priv = nft_expr_priv(expr); 456 457 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) 458 goto nla_put_failure; 459 if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg)) 460 goto nla_put_failure; 461 return 0; 462 463 nla_put_failure: 464 return -1; 465 } 466 EXPORT_SYMBOL_GPL(nft_meta_get_dump); 467 468 int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr) 469 { 470 const struct nft_meta *priv = nft_expr_priv(expr); 471 472 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) 473 goto nla_put_failure; 474 if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg)) 475 goto nla_put_failure; 476 477 return 0; 478 479 nla_put_failure: 480 return -1; 481 } 482 EXPORT_SYMBOL_GPL(nft_meta_set_dump); 483 484 void nft_meta_set_destroy(const struct nft_ctx *ctx, 485 const struct nft_expr *expr) 486 { 487 const struct nft_meta *priv = nft_expr_priv(expr); 488 489 if (priv->key == NFT_META_NFTRACE) 490 static_branch_dec(&nft_trace_enabled); 491 } 492 EXPORT_SYMBOL_GPL(nft_meta_set_destroy); 493 494 static int nft_meta_get_offload(struct nft_offload_ctx *ctx, 495 struct nft_flow_rule *flow, 496 const struct nft_expr *expr) 497 { 498 const struct nft_meta *priv = nft_expr_priv(expr); 499 struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; 500 501 switch (priv->key) { 502 case NFT_META_PROTOCOL: 503 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, n_proto, 504 sizeof(__u16), reg); 505 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK); 506 break; 507 case NFT_META_L4PROTO: 508 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto, 509 sizeof(__u8), reg); 510 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT); 511 break; 512 default: 513 return -EOPNOTSUPP; 514 } 515 516 return 0; 517 } 518 519 static const struct nft_expr_ops nft_meta_get_ops = { 520 .type = &nft_meta_type, 521 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 522 .eval = nft_meta_get_eval, 523 .init = nft_meta_get_init, 524 .dump = nft_meta_get_dump, 525 .validate = nft_meta_get_validate, 526 .offload = nft_meta_get_offload, 527 }; 528 529 static const struct nft_expr_ops nft_meta_set_ops = { 530 .type = &nft_meta_type, 531 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), 532 .eval = nft_meta_set_eval, 533 .init = nft_meta_set_init, 534 .destroy = nft_meta_set_destroy, 535 .dump = nft_meta_set_dump, 536 .validate = nft_meta_set_validate, 537 }; 538 539 static const struct nft_expr_ops * 540 nft_meta_select_ops(const struct nft_ctx *ctx, 541 const struct nlattr * const tb[]) 542 { 543 if (tb[NFTA_META_KEY] == NULL) 544 return ERR_PTR(-EINVAL); 545 546 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG]) 547 return ERR_PTR(-EINVAL); 548 549 #ifdef CONFIG_NF_TABLES_BRIDGE 550 if (ctx->family == NFPROTO_BRIDGE) 551 return ERR_PTR(-EAGAIN); 552 #endif 553 if (tb[NFTA_META_DREG]) 554 return &nft_meta_get_ops; 555 556 if (tb[NFTA_META_SREG]) 557 return &nft_meta_set_ops; 558 559 return ERR_PTR(-EINVAL); 560 } 561 562 struct nft_expr_type nft_meta_type __read_mostly = { 563 .name = "meta", 564 .select_ops = nft_meta_select_ops, 565 .policy = nft_meta_policy, 566 .maxattr = NFTA_META_MAX, 567 .owner = THIS_MODULE, 568 }; 569 570 #ifdef CONFIG_NETWORK_SECMARK 571 struct nft_secmark { 572 u32 secid; 573 char *ctx; 574 }; 575 576 static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = { 577 [NFTA_SECMARK_CTX] = { .type = NLA_STRING, .len = NFT_SECMARK_CTX_MAXLEN }, 578 }; 579 580 static int nft_secmark_compute_secid(struct nft_secmark *priv) 581 { 582 u32 tmp_secid = 0; 583 int err; 584 585 err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid); 586 if (err) 587 return err; 588 589 if (!tmp_secid) 590 return -ENOENT; 591 592 err = security_secmark_relabel_packet(tmp_secid); 593 if (err) 594 return err; 595 596 priv->secid = tmp_secid; 597 return 0; 598 } 599 600 static void nft_secmark_obj_eval(struct nft_object *obj, struct nft_regs *regs, 601 const struct nft_pktinfo *pkt) 602 { 603 const struct nft_secmark *priv = nft_obj_data(obj); 604 struct sk_buff *skb = pkt->skb; 605 606 skb->secmark = priv->secid; 607 } 608 609 static int nft_secmark_obj_init(const struct nft_ctx *ctx, 610 const struct nlattr * const tb[], 611 struct nft_object *obj) 612 { 613 struct nft_secmark *priv = nft_obj_data(obj); 614 int err; 615 616 if (tb[NFTA_SECMARK_CTX] == NULL) 617 return -EINVAL; 618 619 priv->ctx = nla_strdup(tb[NFTA_SECMARK_CTX], GFP_KERNEL); 620 if (!priv->ctx) 621 return -ENOMEM; 622 623 err = nft_secmark_compute_secid(priv); 624 if (err) { 625 kfree(priv->ctx); 626 return err; 627 } 628 629 security_secmark_refcount_inc(); 630 631 return 0; 632 } 633 634 static int nft_secmark_obj_dump(struct sk_buff *skb, struct nft_object *obj, 635 bool reset) 636 { 637 struct nft_secmark *priv = nft_obj_data(obj); 638 int err; 639 640 if (nla_put_string(skb, NFTA_SECMARK_CTX, priv->ctx)) 641 return -1; 642 643 if (reset) { 644 err = nft_secmark_compute_secid(priv); 645 if (err) 646 return err; 647 } 648 649 return 0; 650 } 651 652 static void nft_secmark_obj_destroy(const struct nft_ctx *ctx, struct nft_object *obj) 653 { 654 struct nft_secmark *priv = nft_obj_data(obj); 655 656 security_secmark_refcount_dec(); 657 658 kfree(priv->ctx); 659 } 660 661 static const struct nft_object_ops nft_secmark_obj_ops = { 662 .type = &nft_secmark_obj_type, 663 .size = sizeof(struct nft_secmark), 664 .init = nft_secmark_obj_init, 665 .eval = nft_secmark_obj_eval, 666 .dump = nft_secmark_obj_dump, 667 .destroy = nft_secmark_obj_destroy, 668 }; 669 struct nft_object_type nft_secmark_obj_type __read_mostly = { 670 .type = NFT_OBJECT_SECMARK, 671 .ops = &nft_secmark_obj_ops, 672 .maxattr = NFTA_SECMARK_MAX, 673 .policy = nft_secmark_policy, 674 .owner = THIS_MODULE, 675 }; 676 #endif /* CONFIG_NETWORK_SECMARK */ 677