net/netfilter/nft_meta.c

   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/ip.h>
  21 #include <net/sock.h>
  22 #include <net/tcp_states.h> /* for TCP_TIME_WAIT */
  23 #include <net/netfilter/nf_tables.h>
  24 #include <net/netfilter/nf_tables_core.h>
  25 #include <net/netfilter/nft_meta.h>
  26 #include <net/netfilter/nf_tables_offload.h>
  27
  28 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */
  29
  30 #define NFT_META_SECS_PER_MINUTE        60
  31 #define NFT_META_SECS_PER_HOUR          3600
  32 #define NFT_META_SECS_PER_DAY           86400
  33 #define NFT_META_DAYS_PER_WEEK          7
  34
  35 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);
  36
  37 static u8 nft_meta_weekday(void)
  38 {
  39         time64_t secs = ktime_get_real_seconds();
  40         unsigned int dse;
  41         u8 wday;
  42
  43         secs -= NFT_META_SECS_PER_MINUTE * sys_tz.tz_minuteswest;
  44         dse = div_u64(secs, NFT_META_SECS_PER_DAY);
  45         wday = (4 + dse) % NFT_META_DAYS_PER_WEEK;
  46
  47         return wday;
  48 }
  49
  50 static u32 nft_meta_hour(time64_t secs)
  51 {
  52         struct tm tm;
  53
  54         time64_to_tm(secs, 0, &tm);
  55
  56         return tm.tm_hour * NFT_META_SECS_PER_HOUR
  57                 + tm.tm_min * NFT_META_SECS_PER_MINUTE
  58                 + tm.tm_sec;
  59 }
  60
  61 static noinline_for_stack void
  62 nft_meta_get_eval_time(enum nft_meta_keys key,
  63                        u32 *dest)
  64 {
  65         switch (key) {
  66         case NFT_META_TIME_NS:
  67                 nft_reg_store64(dest, ktime_get_real_ns());
  68                 break;
  69         case NFT_META_TIME_DAY:
  70                 nft_reg_store8(dest, nft_meta_weekday());
  71                 break;
  72         case NFT_META_TIME_HOUR:
  73                 *dest = nft_meta_hour(ktime_get_real_seconds());
  74                 break;
  75         default:
  76                 break;
  77         }
  78 }
  79
  80 static noinline bool
  81 nft_meta_get_eval_pkttype_lo(const struct nft_pktinfo *pkt,
  82                              u32 *dest)
  83 {
  84         const struct sk_buff *skb = pkt->skb;
  85
  86         switch (nft_pf(pkt)) {
  87         case NFPROTO_IPV4:
  88                 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
  89                         nft_reg_store8(dest, PACKET_MULTICAST);
  90                 else
  91                         nft_reg_store8(dest, PACKET_BROADCAST);
  92                 break;
  93         case NFPROTO_IPV6:
  94                 nft_reg_store8(dest, PACKET_MULTICAST);
  95                 break;
  96         case NFPROTO_NETDEV:
  97                 switch (skb->protocol) {
  98                 case htons(ETH_P_IP): {
  99                         int noff = skb_network_offset(skb);
 100                         struct iphdr *iph, _iph;
 101
 102                         iph = skb_header_pointer(skb, noff,
 103                                                  sizeof(_iph), &_iph);
 104                         if (!iph)
 105                                 return false;
 106
 107                         if (ipv4_is_multicast(iph->daddr))
 108                                 nft_reg_store8(dest, PACKET_MULTICAST);
 109                         else
 110                                 nft_reg_store8(dest, PACKET_BROADCAST);
 111
 112                         break;
 113                 }
 114                 case htons(ETH_P_IPV6):
 115                         nft_reg_store8(dest, PACKET_MULTICAST);
 116                         break;
 117                 default:
 118                         WARN_ON_ONCE(1);
 119                         return false;
 120                 }
 121                 break;
 122         default:
 123                 WARN_ON_ONCE(1);
 124                 return false;
 125         }
 126
 127         return true;
 128 }
 129
 130 static noinline bool
 131 nft_meta_get_eval_skugid(enum nft_meta_keys key,
 132                          u32 *dest,
 133                          const struct nft_pktinfo *pkt)
 134 {
 135         struct sock *sk = skb_to_full_sk(pkt->skb);
 136         struct socket *sock;
 137
 138         if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk)))
 139                 return false;
 140
 141         read_lock_bh(&sk->sk_callback_lock);
 142         sock = sk->sk_socket;
 143         if (!sock || !sock->file) {
 144                 read_unlock_bh(&sk->sk_callback_lock);
 145                 return false;
 146         }
 147
 148         switch (key) {
 149         case NFT_META_SKUID:
 150                 *dest = from_kuid_munged(&init_user_ns,
 151                                          sock->file->f_cred->fsuid);
 152                 break;
 153         case NFT_META_SKGID:
 154                 *dest = from_kgid_munged(&init_user_ns,
 155                                          sock->file->f_cred->fsgid);
 156                 break;
 157         default:
 158                 break;
 159         }
 160
 161         read_unlock_bh(&sk->sk_callback_lock);
 162         return true;
 163 }
 164
 165 #ifdef CONFIG_CGROUP_NET_CLASSID
 166 static noinline bool
 167 nft_meta_get_eval_cgroup(u32 *dest, const struct nft_pktinfo *pkt)
 168 {
 169         struct sock *sk = skb_to_full_sk(pkt->skb);
 170
 171         if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk)))
 172                 return false;
 173
 174         *dest = sock_cgroup_classid(&sk->sk_cgrp_data);
 175         return true;
 176 }
 177 #endif
 178
 179 static noinline bool nft_meta_get_eval_kind(enum nft_meta_keys key,
 180                                             u32 *dest,
 181                                             const struct nft_pktinfo *pkt)
 182 {
 183         const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
 184
 185         switch (key) {
 186         case NFT_META_IIFKIND:
 187                 if (!in || !in->rtnl_link_ops)
 188                         return false;
 189                 strncpy((char *)dest, in->rtnl_link_ops->kind, IFNAMSIZ);
 190                 break;
 191         case NFT_META_OIFKIND:
 192                 if (!out || !out->rtnl_link_ops)
 193                         return false;
 194                 strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ);
 195                 break;
 196         default:
 197                 return false;
 198         }
 199
 200         return true;
 201 }
 202
 203 static void nft_meta_store_ifindex(u32 *dest, const struct net_device *dev)
 204 {
 205         *dest = dev ? dev->ifindex : 0;
 206 }
 207
 208 static void nft_meta_store_ifname(u32 *dest, const struct net_device *dev)
 209 {
 210         strncpy((char *)dest, dev ? dev->name : "", IFNAMSIZ);
 211 }
 212
 213 static bool nft_meta_store_iftype(u32 *dest, const struct net_device *dev)
 214 {
 215         if (!dev)
 216                 return false;
 217
 218         nft_reg_store16(dest, dev->type);
 219         return true;
 220 }
 221
 222 static bool nft_meta_store_ifgroup(u32 *dest, const struct net_device *dev)
 223 {
 224         if (!dev)
 225                 return false;
 226
 227         *dest = dev->group;
 228         return true;
 229 }
 230
 231 static bool nft_meta_get_eval_ifname(enum nft_meta_keys key, u32 *dest,
 232                                      const struct nft_pktinfo *pkt)
 233 {
 234         switch (key) {
 235         case NFT_META_IIFNAME:
 236                 nft_meta_store_ifname(dest, nft_in(pkt));
 237                 break;
 238         case NFT_META_OIFNAME:
 239                 nft_meta_store_ifname(dest, nft_out(pkt));
 240                 break;
 241         case NFT_META_IIF:
 242                 nft_meta_store_ifindex(dest, nft_in(pkt));
 243                 break;
 244         case NFT_META_OIF:
 245                 nft_meta_store_ifindex(dest, nft_out(pkt));
 246                 break;
 247         case NFT_META_IIFTYPE:
 248                 if (!nft_meta_store_iftype(dest, nft_in(pkt)))
 249                         return false;
 250                 break;
 251         case NFT_META_OIFTYPE:
 252                 if (!nft_meta_store_iftype(dest, nft_out(pkt)))
 253                         return false;
 254                 break;
 255         case NFT_META_IIFGROUP:
 256                 if (!nft_meta_store_ifgroup(dest, nft_out(pkt)))
 257                         return false;
 258                 break;
 259         case NFT_META_OIFGROUP:
 260                 if (!nft_meta_store_ifgroup(dest, nft_out(pkt)))
 261                         return false;
 262                 break;
 263         default:
 264                 return false;
 265         }
 266
 267         return true;
 268 }
 269
 270 static noinline u32 nft_prandom_u32(void)
 271 {
 272         struct rnd_state *state = this_cpu_ptr(&nft_prandom_state);
 273
 274         return prandom_u32_state(state);
 275 }
 276
 277 #ifdef CONFIG_IP_ROUTE_CLASSID
 278 static noinline bool
 279 nft_meta_get_eval_rtclassid(const struct sk_buff *skb, u32 *dest)
 280 {
 281         const struct dst_entry *dst = skb_dst(skb);
 282
 283         if (!dst)
 284                 return false;
 285
 286         *dest = dst->tclassid;
 287         return true;
 288 }
 289 #endif
 290
 291 static noinline u32 nft_meta_get_eval_sdif(const struct nft_pktinfo *pkt)
 292 {
 293         switch (nft_pf(pkt)) {
 294         case NFPROTO_IPV4:
 295                 return inet_sdif(pkt->skb);
 296         case NFPROTO_IPV6:
 297                 return inet6_sdif(pkt->skb);
 298         }
 299
 300         return 0;
 301 }
 302
 303 static noinline void
 304 nft_meta_get_eval_sdifname(u32 *dest, const struct nft_pktinfo *pkt)
 305 {
 306         u32 sdif = nft_meta_get_eval_sdif(pkt);
 307         const struct net_device *dev;
 308
 309         dev = sdif ? dev_get_by_index_rcu(nft_net(pkt), sdif) : NULL;
 310         nft_meta_store_ifname(dest, dev);
 311 }
 312
 313 void nft_meta_get_eval(const struct nft_expr *expr,
 314                        struct nft_regs *regs,
 315                        const struct nft_pktinfo *pkt)
 316 {
 317         const struct nft_meta *priv = nft_expr_priv(expr);
 318         const struct sk_buff *skb = pkt->skb;
 319         u32 *dest = &regs->data[priv->dreg];
 320
 321         switch (priv->key) {
 322         case NFT_META_LEN:
 323                 *dest = skb->len;
 324                 break;
 325         case NFT_META_PROTOCOL:
 326                 nft_reg_store16(dest, (__force u16)skb->protocol);
 327                 break;
 328         case NFT_META_NFPROTO:
 329                 nft_reg_store8(dest, nft_pf(pkt));
 330                 break;
 331         case NFT_META_L4PROTO:
 332                 if (!pkt->tprot_set)
 333                         goto err;
 334                 nft_reg_store8(dest, pkt->tprot);
 335                 break;
 336         case NFT_META_PRIORITY:
 337                 *dest = skb->priority;
 338                 break;
 339         case NFT_META_MARK:
 340                 *dest = skb->mark;
 341                 break;
 342         case NFT_META_IIF:
 343         case NFT_META_OIF:
 344         case NFT_META_IIFNAME:
 345         case NFT_META_OIFNAME:
 346         case NFT_META_IIFTYPE:
 347         case NFT_META_OIFTYPE:
 348         case NFT_META_IIFGROUP:
 349         case NFT_META_OIFGROUP:
 350                 if (!nft_meta_get_eval_ifname(priv->key, dest, pkt))
 351                         goto err;
 352                 break;
 353         case NFT_META_SKUID:
 354         case NFT_META_SKGID:
 355                 if (!nft_meta_get_eval_skugid(priv->key, dest, pkt))
 356                         goto err;
 357                 break;
 358 #ifdef CONFIG_IP_ROUTE_CLASSID
 359         case NFT_META_RTCLASSID:
 360                 if (!nft_meta_get_eval_rtclassid(skb, dest))
 361                         goto err;
 362                 break;
 363 #endif
 364 #ifdef CONFIG_NETWORK_SECMARK
 365         case NFT_META_SECMARK:
 366                 *dest = skb->secmark;
 367                 break;
 368 #endif
 369         case NFT_META_PKTTYPE:
 370                 if (skb->pkt_type != PACKET_LOOPBACK) {
 371                         nft_reg_store8(dest, skb->pkt_type);
 372                         break;
 373                 }
 374
 375                 if (!nft_meta_get_eval_pkttype_lo(pkt, dest))
 376                         goto err;
 377                 break;
 378         case NFT_META_CPU:
 379                 *dest = raw_smp_processor_id();
 380                 break;
 381 #ifdef CONFIG_CGROUP_NET_CLASSID
 382         case NFT_META_CGROUP:
 383                 if (!nft_meta_get_eval_cgroup(dest, pkt))
 384                         goto err;
 385                 break;
 386 #endif
 387         case NFT_META_PRANDOM:
 388                 *dest = nft_prandom_u32();
 389                 break;
 390 #ifdef CONFIG_XFRM
 391         case NFT_META_SECPATH:
 392                 nft_reg_store8(dest, secpath_exists(skb));
 393                 break;
 394 #endif
 395         case NFT_META_IIFKIND:
 396         case NFT_META_OIFKIND:
 397                 if (!nft_meta_get_eval_kind(priv->key, dest, pkt))
 398                         goto err;
 399                 break;
 400         case NFT_META_TIME_NS:
 401         case NFT_META_TIME_DAY:
 402         case NFT_META_TIME_HOUR:
 403                 nft_meta_get_eval_time(priv->key, dest);
 404                 break;
 405         case NFT_META_SDIF:
 406                 *dest = nft_meta_get_eval_sdif(pkt);
 407                 break;
 408         case NFT_META_SDIFNAME:
 409                 nft_meta_get_eval_sdifname(dest, pkt);
 410                 break;
 411         default:
 412                 WARN_ON(1);
 413                 goto err;
 414         }
 415         return;
 416
 417 err:
 418         regs->verdict.code = NFT_BREAK;
 419 }
 420 EXPORT_SYMBOL_GPL(nft_meta_get_eval);
 421
 422 void nft_meta_set_eval(const struct nft_expr *expr,
 423                        struct nft_regs *regs,
 424                        const struct nft_pktinfo *pkt)
 425 {
 426         const struct nft_meta *meta = nft_expr_priv(expr);
 427         struct sk_buff *skb = pkt->skb;
 428         u32 *sreg = &regs->data[meta->sreg];
 429         u32 value = *sreg;
 430         u8 value8;
 431
 432         switch (meta->key) {
 433         case NFT_META_MARK:
 434                 skb->mark = value;
 435                 break;
 436         case NFT_META_PRIORITY:
 437                 skb->priority = value;
 438                 break;
 439         case NFT_META_PKTTYPE:
 440                 value8 = nft_reg_load8(sreg);
 441
 442                 if (skb->pkt_type != value8 &&
 443                     skb_pkt_type_ok(value8) &&
 444                     skb_pkt_type_ok(skb->pkt_type))
 445                         skb->pkt_type = value8;
 446                 break;
 447         case NFT_META_NFTRACE:
 448                 value8 = nft_reg_load8(sreg);
 449
 450                 skb->nf_trace = !!value8;
 451                 break;
 452 #ifdef CONFIG_NETWORK_SECMARK
 453         case NFT_META_SECMARK:
 454                 skb->secmark = value;
 455                 break;
 456 #endif
 457         default:
 458                 WARN_ON(1);
 459         }
 460 }
 461 EXPORT_SYMBOL_GPL(nft_meta_set_eval);
 462
 463 const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
 464         [NFTA_META_DREG]        = { .type = NLA_U32 },
 465         [NFTA_META_KEY]         = { .type = NLA_U32 },
 466         [NFTA_META_SREG]        = { .type = NLA_U32 },
 467 };
 468 EXPORT_SYMBOL_GPL(nft_meta_policy);
 469
 470 int nft_meta_get_init(const struct nft_ctx *ctx,
 471                       const struct nft_expr *expr,
 472                       const struct nlattr * const tb[])
 473 {
 474         struct nft_meta *priv = nft_expr_priv(expr);
 475         unsigned int len;
 476
 477         priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
 478         switch (priv->key) {
 479         case NFT_META_PROTOCOL:
 480         case NFT_META_IIFTYPE:
 481         case NFT_META_OIFTYPE:
 482                 len = sizeof(u16);
 483                 break;
 484         case NFT_META_NFPROTO:
 485         case NFT_META_L4PROTO:
 486         case NFT_META_LEN:
 487         case NFT_META_PRIORITY:
 488         case NFT_META_MARK:
 489         case NFT_META_IIF:
 490         case NFT_META_OIF:
 491         case NFT_META_SDIF:
 492         case NFT_META_SKUID:
 493         case NFT_META_SKGID:
 494 #ifdef CONFIG_IP_ROUTE_CLASSID
 495         case NFT_META_RTCLASSID:
 496 #endif
 497 #ifdef CONFIG_NETWORK_SECMARK
 498         case NFT_META_SECMARK:
 499 #endif
 500         case NFT_META_PKTTYPE:
 501         case NFT_META_CPU:
 502         case NFT_META_IIFGROUP:
 503         case NFT_META_OIFGROUP:
 504 #ifdef CONFIG_CGROUP_NET_CLASSID
 505         case NFT_META_CGROUP:
 506 #endif
 507                 len = sizeof(u32);
 508                 break;
 509         case NFT_META_IIFNAME:
 510         case NFT_META_OIFNAME:
 511         case NFT_META_IIFKIND:
 512         case NFT_META_OIFKIND:
 513         case NFT_META_SDIFNAME:
 514                 len = IFNAMSIZ;
 515                 break;
 516         case NFT_META_PRANDOM:
 517                 prandom_init_once(&nft_prandom_state);
 518                 len = sizeof(u32);
 519                 break;
 520 #ifdef CONFIG_XFRM
 521         case NFT_META_SECPATH:
 522                 len = sizeof(u8);
 523                 break;
 524 #endif
 525         case NFT_META_TIME_NS:
 526                 len = sizeof(u64);
 527                 break;
 528         case NFT_META_TIME_DAY:
 529                 len = sizeof(u8);
 530                 break;
 531         case NFT_META_TIME_HOUR:
 532                 len = sizeof(u32);
 533                 break;
 534         default:
 535                 return -EOPNOTSUPP;
 536         }
 537
 538         priv->dreg = nft_parse_register(tb[NFTA_META_DREG]);
 539         return nft_validate_register_store(ctx, priv->dreg, NULL,
 540                                            NFT_DATA_VALUE, len);
 541 }
 542 EXPORT_SYMBOL_GPL(nft_meta_get_init);
 543
 544 static int nft_meta_get_validate_sdif(const struct nft_ctx *ctx)
 545 {
 546         unsigned int hooks;
 547
 548         switch (ctx->family) {
 549         case NFPROTO_IPV4:
 550         case NFPROTO_IPV6:
 551         case NFPROTO_INET:
 552                 hooks = (1 << NF_INET_LOCAL_IN) |
 553                         (1 << NF_INET_FORWARD);
 554                 break;
 555         default:
 556                 return -EOPNOTSUPP;
 557         }
 558
 559         return nft_chain_validate_hooks(ctx->chain, hooks);
 560 }
 561
 562 static int nft_meta_get_validate_xfrm(const struct nft_ctx *ctx)
 563 {
 564 #ifdef CONFIG_XFRM
 565         unsigned int hooks;
 566
 567         switch (ctx->family) {
 568         case NFPROTO_NETDEV:
 569                 hooks = 1 << NF_NETDEV_INGRESS;
 570                 break;
 571         case NFPROTO_IPV4:
 572         case NFPROTO_IPV6:
 573         case NFPROTO_INET:
 574                 hooks = (1 << NF_INET_PRE_ROUTING) |
 575                         (1 << NF_INET_LOCAL_IN) |
 576                         (1 << NF_INET_FORWARD);
 577                 break;
 578         default:
 579                 return -EOPNOTSUPP;
 580         }
 581
 582         return nft_chain_validate_hooks(ctx->chain, hooks);
 583 #else
 584         return 0;
 585 #endif
 586 }
 587
 588 static int nft_meta_get_validate(const struct nft_ctx *ctx,
 589                                  const struct nft_expr *expr,
 590                                  const struct nft_data **data)
 591 {
 592         const struct nft_meta *priv = nft_expr_priv(expr);
 593
 594         switch (priv->key) {
 595         case NFT_META_SECPATH:
 596                 return nft_meta_get_validate_xfrm(ctx);
 597         case NFT_META_SDIF:
 598         case NFT_META_SDIFNAME:
 599                 return nft_meta_get_validate_sdif(ctx);
 600         default:
 601                 break;
 602         }
 603
 604         return 0;
 605 }
 606
 607 int nft_meta_set_validate(const struct nft_ctx *ctx,
 608                           const struct nft_expr *expr,
 609                           const struct nft_data **data)
 610 {
 611         struct nft_meta *priv = nft_expr_priv(expr);
 612         unsigned int hooks;
 613
 614         if (priv->key != NFT_META_PKTTYPE)
 615                 return 0;
 616
 617         switch (ctx->family) {
 618         case NFPROTO_BRIDGE:
 619                 hooks = 1 << NF_BR_PRE_ROUTING;
 620                 break;
 621         case NFPROTO_NETDEV:
 622                 hooks = 1 << NF_NETDEV_INGRESS;
 623                 break;
 624         case NFPROTO_IPV4:
 625         case NFPROTO_IPV6:
 626         case NFPROTO_INET:
 627                 hooks = 1 << NF_INET_PRE_ROUTING;
 628                 break;
 629         default:
 630                 return -EOPNOTSUPP;
 631         }
 632
 633         return nft_chain_validate_hooks(ctx->chain, hooks);
 634 }
 635 EXPORT_SYMBOL_GPL(nft_meta_set_validate);
 636
 637 int nft_meta_set_init(const struct nft_ctx *ctx,
 638                       const struct nft_expr *expr,
 639                       const struct nlattr * const tb[])
 640 {
 641         struct nft_meta *priv = nft_expr_priv(expr);
 642         unsigned int len;
 643         int err;
 644
 645         priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
 646         switch (priv->key) {
 647         case NFT_META_MARK:
 648         case NFT_META_PRIORITY:
 649 #ifdef CONFIG_NETWORK_SECMARK
 650         case NFT_META_SECMARK:
 651 #endif
 652                 len = sizeof(u32);
 653                 break;
 654         case NFT_META_NFTRACE:
 655                 len = sizeof(u8);
 656                 break;
 657         case NFT_META_PKTTYPE:
 658                 len = sizeof(u8);
 659                 break;
 660         default:
 661                 return -EOPNOTSUPP;
 662         }
 663
 664         priv->sreg = nft_parse_register(tb[NFTA_META_SREG]);
 665         err = nft_validate_register_load(priv->sreg, len);
 666         if (err < 0)
 667                 return err;
 668
 669         if (priv->key == NFT_META_NFTRACE)
 670                 static_branch_inc(&nft_trace_enabled);
 671
 672         return 0;
 673 }
 674 EXPORT_SYMBOL_GPL(nft_meta_set_init);
 675
 676 int nft_meta_get_dump(struct sk_buff *skb,
 677                       const struct nft_expr *expr)
 678 {
 679         const struct nft_meta *priv = nft_expr_priv(expr);
 680
 681         if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
 682                 goto nla_put_failure;
 683         if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg))
 684                 goto nla_put_failure;
 685         return 0;
 686
 687 nla_put_failure:
 688         return -1;
 689 }
 690 EXPORT_SYMBOL_GPL(nft_meta_get_dump);
 691
 692 int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
 693 {
 694         const struct nft_meta *priv = nft_expr_priv(expr);
 695
 696         if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
 697                 goto nla_put_failure;
 698         if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg))
 699                 goto nla_put_failure;
 700
 701         return 0;
 702
 703 nla_put_failure:
 704         return -1;
 705 }
 706 EXPORT_SYMBOL_GPL(nft_meta_set_dump);
 707
 708 void nft_meta_set_destroy(const struct nft_ctx *ctx,
 709                           const struct nft_expr *expr)
 710 {
 711         const struct nft_meta *priv = nft_expr_priv(expr);
 712
 713         if (priv->key == NFT_META_NFTRACE)
 714                 static_branch_dec(&nft_trace_enabled);
 715 }
 716 EXPORT_SYMBOL_GPL(nft_meta_set_destroy);
 717
 718 static int nft_meta_get_offload(struct nft_offload_ctx *ctx,
 719                                 struct nft_flow_rule *flow,
 720                                 const struct nft_expr *expr)
 721 {
 722         const struct nft_meta *priv = nft_expr_priv(expr);
 723         struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
 724
 725         switch (priv->key) {
 726         case NFT_META_PROTOCOL:
 727                 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, n_proto,
 728                                   sizeof(__u16), reg);
 729                 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
 730                 break;
 731         case NFT_META_L4PROTO:
 732                 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
 733                                   sizeof(__u8), reg);
 734                 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
 735                 break;
 736         case NFT_META_IIF:
 737                 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_META, meta,
 738                                   ingress_ifindex, sizeof(__u32), reg);
 739                 break;
 740         case NFT_META_IIFTYPE:
 741                 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_META, meta,
 742                                   ingress_iftype, sizeof(__u16), reg);
 743                 break;
 744         default:
 745                 return -EOPNOTSUPP;
 746         }
 747
 748         return 0;
 749 }
 750
 751 static const struct nft_expr_ops nft_meta_get_ops = {
 752         .type           = &nft_meta_type,
 753         .size           = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
 754         .eval           = nft_meta_get_eval,
 755         .init           = nft_meta_get_init,
 756         .dump           = nft_meta_get_dump,
 757         .validate       = nft_meta_get_validate,
 758         .offload        = nft_meta_get_offload,
 759 };
 760
 761 static const struct nft_expr_ops nft_meta_set_ops = {
 762         .type           = &nft_meta_type,
 763         .size           = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
 764         .eval           = nft_meta_set_eval,
 765         .init           = nft_meta_set_init,
 766         .destroy        = nft_meta_set_destroy,
 767         .dump           = nft_meta_set_dump,
 768         .validate       = nft_meta_set_validate,
 769 };
 770
 771 static const struct nft_expr_ops *
 772 nft_meta_select_ops(const struct nft_ctx *ctx,
 773                     const struct nlattr * const tb[])
 774 {
 775         if (tb[NFTA_META_KEY] == NULL)
 776                 return ERR_PTR(-EINVAL);
 777
 778         if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
 779                 return ERR_PTR(-EINVAL);
 780
 781 #if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE) && IS_MODULE(CONFIG_NFT_BRIDGE_META)
 782         if (ctx->family == NFPROTO_BRIDGE)
 783                 return ERR_PTR(-EAGAIN);
 784 #endif
 785         if (tb[NFTA_META_DREG])
 786                 return &nft_meta_get_ops;
 787
 788         if (tb[NFTA_META_SREG])
 789                 return &nft_meta_set_ops;
 790
 791         return ERR_PTR(-EINVAL);
 792 }
 793
 794 struct nft_expr_type nft_meta_type __read_mostly = {
 795         .name           = "meta",
 796         .select_ops     = nft_meta_select_ops,
 797         .policy         = nft_meta_policy,
 798         .maxattr        = NFTA_META_MAX,
 799         .owner          = THIS_MODULE,
 800 };
 801
 802 #ifdef CONFIG_NETWORK_SECMARK
 803 struct nft_secmark {
 804         u32 secid;
 805         char *ctx;
 806 };
 807
 808 static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
 809         [NFTA_SECMARK_CTX]     = { .type = NLA_STRING, .len = NFT_SECMARK_CTX_MAXLEN },
 810 };
 811
 812 static int nft_secmark_compute_secid(struct nft_secmark *priv)
 813 {
 814         u32 tmp_secid = 0;
 815         int err;
 816
 817         err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
 818         if (err)
 819                 return err;
 820
 821         if (!tmp_secid)
 822                 return -ENOENT;
 823
 824         err = security_secmark_relabel_packet(tmp_secid);
 825         if (err)
 826                 return err;
 827
 828         priv->secid = tmp_secid;
 829         return 0;
 830 }
 831
 832 static void nft_secmark_obj_eval(struct nft_object *obj, struct nft_regs *regs,
 833                                  const struct nft_pktinfo *pkt)
 834 {
 835         const struct nft_secmark *priv = nft_obj_data(obj);
 836         struct sk_buff *skb = pkt->skb;
 837
 838         skb->secmark = priv->secid;
 839 }
 840
 841 static int nft_secmark_obj_init(const struct nft_ctx *ctx,
 842                                 const struct nlattr * const tb[],
 843                                 struct nft_object *obj)
 844 {
 845         struct nft_secmark *priv = nft_obj_data(obj);
 846         int err;
 847
 848         if (tb[NFTA_SECMARK_CTX] == NULL)
 849                 return -EINVAL;
 850
 851         priv->ctx = nla_strdup(tb[NFTA_SECMARK_CTX], GFP_KERNEL);
 852         if (!priv->ctx)
 853                 return -ENOMEM;
 854
 855         err = nft_secmark_compute_secid(priv);
 856         if (err) {
 857                 kfree(priv->ctx);
 858                 return err;
 859         }
 860
 861         security_secmark_refcount_inc();
 862
 863         return 0;
 864 }
 865
 866 static int nft_secmark_obj_dump(struct sk_buff *skb, struct nft_object *obj,
 867                                 bool reset)
 868 {
 869         struct nft_secmark *priv = nft_obj_data(obj);
 870         int err;
 871
 872         if (nla_put_string(skb, NFTA_SECMARK_CTX, priv->ctx))
 873                 return -1;
 874
 875         if (reset) {
 876                 err = nft_secmark_compute_secid(priv);
 877                 if (err)
 878                         return err;
 879         }
 880
 881         return 0;
 882 }
 883
 884 static void nft_secmark_obj_destroy(const struct nft_ctx *ctx, struct nft_object *obj)
 885 {
 886         struct nft_secmark *priv = nft_obj_data(obj);
 887
 888         security_secmark_refcount_dec();
 889
 890         kfree(priv->ctx);
 891 }
 892
 893 static const struct nft_object_ops nft_secmark_obj_ops = {
 894         .type           = &nft_secmark_obj_type,
 895         .size           = sizeof(struct nft_secmark),
 896         .init           = nft_secmark_obj_init,
 897         .eval           = nft_secmark_obj_eval,
 898         .dump           = nft_secmark_obj_dump,
 899         .destroy        = nft_secmark_obj_destroy,
 900 };
 901 struct nft_object_type nft_secmark_obj_type __read_mostly = {
 902         .type           = NFT_OBJECT_SECMARK,
 903         .ops            = &nft_secmark_obj_ops,
 904         .maxattr        = NFTA_SECMARK_MAX,
 905         .policy         = nft_secmark_policy,
 906         .owner          = THIS_MODULE,
 907 };
 908 #endif /* CONFIG_NETWORK_SECMARK */