net/core/flow_dissector.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/kernel.h>
   3 #include <linux/skbuff.h>
   4 #include <linux/export.h>
   5 #include <linux/ip.h>
   6 #include <linux/ipv6.h>
   7 #include <linux/if_vlan.h>
   8 #include <linux/filter.h>
   9 #include <net/dsa.h>
  10 #include <net/dst_metadata.h>
  11 #include <net/ip.h>
  12 #include <net/ipv6.h>
  13 #include <net/gre.h>
  14 #include <net/pptp.h>
  15 #include <net/tipc.h>
  16 #include <linux/igmp.h>
  17 #include <linux/icmp.h>
  18 #include <linux/sctp.h>
  19 #include <linux/dccp.h>
  20 #include <linux/if_tunnel.h>
  21 #include <linux/if_pppox.h>
  22 #include <linux/ppp_defs.h>
  23 #include <linux/stddef.h>
  24 #include <linux/if_ether.h>
  25 #include <linux/if_hsr.h>
  26 #include <linux/mpls.h>
  27 #include <linux/tcp.h>
  28 #include <linux/ptp_classify.h>
  29 #include <net/flow_dissector.h>
  30 #include <net/pkt_cls.h>
  31 #include <scsi/fc/fc_fcoe.h>
  32 #include <uapi/linux/batadv_packet.h>
  33 #include <linux/bpf.h>
  34 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  35 #include <net/netfilter/nf_conntrack_core.h>
  36 #include <net/netfilter/nf_conntrack_labels.h>
  37 #endif
  38 #include <linux/bpf-netns.h>
  39
  40 static void dissector_set_key(struct flow_dissector *flow_dissector,
  41                               enum flow_dissector_key_id key_id)
  42 {
  43         flow_dissector->used_keys |= (1ULL << key_id);
  44 }
  45
  46 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  47                              const struct flow_dissector_key *key,
  48                              unsigned int key_count)
  49 {
  50         unsigned int i;
  51
  52         memset(flow_dissector, 0, sizeof(*flow_dissector));
  53
  54         for (i = 0; i < key_count; i++, key++) {
  55                 /* User should make sure that every key target offset is within
  56                  * boundaries of unsigned short.
  57                  */
  58                 BUG_ON(key->offset > USHRT_MAX);
  59                 BUG_ON(dissector_uses_key(flow_dissector,
  60                                           key->key_id));
  61
  62                 dissector_set_key(flow_dissector, key->key_id);
  63                 flow_dissector->offset[key->key_id] = key->offset;
  64         }
  65
  66         /* Ensure that the dissector always includes control and basic key.
  67          * That way we are able to avoid handling lack of these in fast path.
  68          */
  69         BUG_ON(!dissector_uses_key(flow_dissector,
  70                                    FLOW_DISSECTOR_KEY_CONTROL));
  71         BUG_ON(!dissector_uses_key(flow_dissector,
  72                                    FLOW_DISSECTOR_KEY_BASIC));
  73 }
  74 EXPORT_SYMBOL(skb_flow_dissector_init);
  75
  76 #ifdef CONFIG_BPF_SYSCALL
  77 int flow_dissector_bpf_prog_attach_check(struct net *net,
  78                                          struct bpf_prog *prog)
  79 {
  80         enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
  81
  82         if (net == &init_net) {
  83                 /* BPF flow dissector in the root namespace overrides
  84                  * any per-net-namespace one. When attaching to root,
  85                  * make sure we don't have any BPF program attached
  86                  * to the non-root namespaces.
  87                  */
  88                 struct net *ns;
  89
  90                 for_each_net(ns) {
  91                         if (ns == &init_net)
  92                                 continue;
  93                         if (rcu_access_pointer(ns->bpf.run_array[type]))
  94                                 return -EEXIST;
  95                 }
  96         } else {
  97                 /* Make sure root flow dissector is not attached
  98                  * when attaching to the non-root namespace.
  99                  */
 100                 if (rcu_access_pointer(init_net.bpf.run_array[type]))
 101                         return -EEXIST;
 102         }
 103
 104         return 0;
 105 }
 106 #endif /* CONFIG_BPF_SYSCALL */
 107
 108 /**
 109  * __skb_flow_get_ports - extract the upper layer ports and return them
 110  * @skb: sk_buff to extract the ports from
 111  * @thoff: transport header offset
 112  * @ip_proto: protocol for which to get port offset
 113  * @data: raw buffer pointer to the packet, if NULL use skb->data
 114  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 115  *
 116  * The function will try to retrieve the ports at offset thoff + poff where poff
 117  * is the protocol port offset returned from proto_ports_offset
 118  */
 119 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
 120                             const void *data, int hlen)
 121 {
 122         int poff = proto_ports_offset(ip_proto);
 123
 124         if (!data) {
 125                 data = skb->data;
 126                 hlen = skb_headlen(skb);
 127         }
 128
 129         if (poff >= 0) {
 130                 __be32 *ports, _ports;
 131
 132                 ports = __skb_header_pointer(skb, thoff + poff,
 133                                              sizeof(_ports), data, hlen, &_ports);
 134                 if (ports)
 135                         return *ports;
 136         }
 137
 138         return 0;
 139 }
 140 EXPORT_SYMBOL(__skb_flow_get_ports);
 141
 142 static bool icmp_has_id(u8 type)
 143 {
 144         switch (type) {
 145         case ICMP_ECHO:
 146         case ICMP_ECHOREPLY:
 147         case ICMP_TIMESTAMP:
 148         case ICMP_TIMESTAMPREPLY:
 149         case ICMPV6_ECHO_REQUEST:
 150         case ICMPV6_ECHO_REPLY:
 151                 return true;
 152         }
 153
 154         return false;
 155 }
 156
 157 /**
 158  * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields
 159  * @skb: sk_buff to extract from
 160  * @key_icmp: struct flow_dissector_key_icmp to fill
 161  * @data: raw buffer pointer to the packet
 162  * @thoff: offset to extract at
 163  * @hlen: packet header length
 164  */
 165 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
 166                            struct flow_dissector_key_icmp *key_icmp,
 167                            const void *data, int thoff, int hlen)
 168 {
 169         struct icmphdr *ih, _ih;
 170
 171         ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih);
 172         if (!ih)
 173                 return;
 174
 175         key_icmp->type = ih->type;
 176         key_icmp->code = ih->code;
 177
 178         /* As we use 0 to signal that the Id field is not present,
 179          * avoid confusion with packets without such field
 180          */
 181         if (icmp_has_id(ih->type))
 182                 key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1;
 183         else
 184                 key_icmp->id = 0;
 185 }
 186 EXPORT_SYMBOL(skb_flow_get_icmp_tci);
 187
 188 /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet
 189  * using skb_flow_get_icmp_tci().
 190  */
 191 static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
 192                                     struct flow_dissector *flow_dissector,
 193                                     void *target_container, const void *data,
 194                                     int thoff, int hlen)
 195 {
 196         struct flow_dissector_key_icmp *key_icmp;
 197
 198         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
 199                 return;
 200
 201         key_icmp = skb_flow_dissector_target(flow_dissector,
 202                                              FLOW_DISSECTOR_KEY_ICMP,
 203                                              target_container);
 204
 205         skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);
 206 }
 207
 208 static void __skb_flow_dissect_ah(const struct sk_buff *skb,
 209                                   struct flow_dissector *flow_dissector,
 210                                   void *target_container, const void *data,
 211                                   int nhoff, int hlen)
 212 {
 213         struct flow_dissector_key_ipsec *key_ah;
 214         struct ip_auth_hdr _hdr, *hdr;
 215
 216         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC))
 217                 return;
 218
 219         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 220         if (!hdr)
 221                 return;
 222
 223         key_ah = skb_flow_dissector_target(flow_dissector,
 224                                            FLOW_DISSECTOR_KEY_IPSEC,
 225                                            target_container);
 226
 227         key_ah->spi = hdr->spi;
 228 }
 229
 230 static void __skb_flow_dissect_esp(const struct sk_buff *skb,
 231                                    struct flow_dissector *flow_dissector,
 232                                    void *target_container, const void *data,
 233                                    int nhoff, int hlen)
 234 {
 235         struct flow_dissector_key_ipsec *key_esp;
 236         struct ip_esp_hdr _hdr, *hdr;
 237
 238         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC))
 239                 return;
 240
 241         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 242         if (!hdr)
 243                 return;
 244
 245         key_esp = skb_flow_dissector_target(flow_dissector,
 246                                             FLOW_DISSECTOR_KEY_IPSEC,
 247                                             target_container);
 248
 249         key_esp->spi = hdr->spi;
 250 }
 251
 252 static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb,
 253                                       struct flow_dissector *flow_dissector,
 254                                       void *target_container, const void *data,
 255                                       int nhoff, int hlen)
 256 {
 257         struct flow_dissector_key_l2tpv3 *key_l2tpv3;
 258         struct {
 259                 __be32 session_id;
 260         } *hdr, _hdr;
 261
 262         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3))
 263                 return;
 264
 265         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 266         if (!hdr)
 267                 return;
 268
 269         key_l2tpv3 = skb_flow_dissector_target(flow_dissector,
 270                                                FLOW_DISSECTOR_KEY_L2TPV3,
 271                                                target_container);
 272
 273         key_l2tpv3->session_id = hdr->session_id;
 274 }
 275
 276 void skb_flow_dissect_meta(const struct sk_buff *skb,
 277                            struct flow_dissector *flow_dissector,
 278                            void *target_container)
 279 {
 280         struct flow_dissector_key_meta *meta;
 281
 282         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
 283                 return;
 284
 285         meta = skb_flow_dissector_target(flow_dissector,
 286                                          FLOW_DISSECTOR_KEY_META,
 287                                          target_container);
 288         meta->ingress_ifindex = skb->skb_iif;
 289 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 290         if (tc_skb_ext_tc_enabled()) {
 291                 struct tc_skb_ext *ext;
 292
 293                 ext = skb_ext_find(skb, TC_SKB_EXT);
 294                 if (ext)
 295                         meta->l2_miss = ext->l2_miss;
 296         }
 297 #endif
 298 }
 299 EXPORT_SYMBOL(skb_flow_dissect_meta);
 300
 301 static void
 302 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
 303                                    struct flow_dissector *flow_dissector,
 304                                    void *target_container)
 305 {
 306         struct flow_dissector_key_control *ctrl;
 307
 308         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
 309                 return;
 310
 311         ctrl = skb_flow_dissector_target(flow_dissector,
 312                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
 313                                          target_container);
 314         ctrl->addr_type = type;
 315 }
 316
 317 void
 318 skb_flow_dissect_ct(const struct sk_buff *skb,
 319                     struct flow_dissector *flow_dissector,
 320                     void *target_container, u16 *ctinfo_map,
 321                     size_t mapsize, bool post_ct, u16 zone)
 322 {
 323 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 324         struct flow_dissector_key_ct *key;
 325         enum ip_conntrack_info ctinfo;
 326         struct nf_conn_labels *cl;
 327         struct nf_conn *ct;
 328
 329         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
 330                 return;
 331
 332         ct = nf_ct_get(skb, &ctinfo);
 333         if (!ct && !post_ct)
 334                 return;
 335
 336         key = skb_flow_dissector_target(flow_dissector,
 337                                         FLOW_DISSECTOR_KEY_CT,
 338                                         target_container);
 339
 340         if (!ct) {
 341                 key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED |
 342                                 TCA_FLOWER_KEY_CT_FLAGS_INVALID;
 343                 key->ct_zone = zone;
 344                 return;
 345         }
 346
 347         if (ctinfo < mapsize)
 348                 key->ct_state = ctinfo_map[ctinfo];
 349 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
 350         key->ct_zone = ct->zone.id;
 351 #endif
 352 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 353         key->ct_mark = READ_ONCE(ct->mark);
 354 #endif
 355
 356         cl = nf_ct_labels_find(ct);
 357         if (cl)
 358                 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
 359 #endif /* CONFIG_NF_CONNTRACK */
 360 }
 361 EXPORT_SYMBOL(skb_flow_dissect_ct);
 362
 363 void
 364 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
 365                              struct flow_dissector *flow_dissector,
 366                              void *target_container)
 367 {
 368         struct ip_tunnel_info *info;
 369         struct ip_tunnel_key *key;
 370
 371         /* A quick check to see if there might be something to do. */
 372         if (!dissector_uses_key(flow_dissector,
 373                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
 374             !dissector_uses_key(flow_dissector,
 375                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
 376             !dissector_uses_key(flow_dissector,
 377                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
 378             !dissector_uses_key(flow_dissector,
 379                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
 380             !dissector_uses_key(flow_dissector,
 381                                 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
 382             !dissector_uses_key(flow_dissector,
 383                                 FLOW_DISSECTOR_KEY_ENC_IP) &&
 384             !dissector_uses_key(flow_dissector,
 385                                 FLOW_DISSECTOR_KEY_ENC_OPTS))
 386                 return;
 387
 388         info = skb_tunnel_info(skb);
 389         if (!info)
 390                 return;
 391
 392         key = &info->key;
 393
 394         switch (ip_tunnel_info_af(info)) {
 395         case AF_INET:
 396                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 397                                                    flow_dissector,
 398                                                    target_container);
 399                 if (dissector_uses_key(flow_dissector,
 400                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 401                         struct flow_dissector_key_ipv4_addrs *ipv4;
 402
 403                         ipv4 = skb_flow_dissector_target(flow_dissector,
 404                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 405                                                          target_container);
 406                         ipv4->src = key->u.ipv4.src;
 407                         ipv4->dst = key->u.ipv4.dst;
 408                 }
 409                 break;
 410         case AF_INET6:
 411                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 412                                                    flow_dissector,
 413                                                    target_container);
 414                 if (dissector_uses_key(flow_dissector,
 415                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 416                         struct flow_dissector_key_ipv6_addrs *ipv6;
 417
 418                         ipv6 = skb_flow_dissector_target(flow_dissector,
 419                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 420                                                          target_container);
 421                         ipv6->src = key->u.ipv6.src;
 422                         ipv6->dst = key->u.ipv6.dst;
 423                 }
 424                 break;
 425         }
 426
 427         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 428                 struct flow_dissector_key_keyid *keyid;
 429
 430                 keyid = skb_flow_dissector_target(flow_dissector,
 431                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
 432                                                   target_container);
 433                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
 434         }
 435
 436         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 437                 struct flow_dissector_key_ports *tp;
 438
 439                 tp = skb_flow_dissector_target(flow_dissector,
 440                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
 441                                                target_container);
 442                 tp->src = key->tp_src;
 443                 tp->dst = key->tp_dst;
 444         }
 445
 446         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
 447                 struct flow_dissector_key_ip *ip;
 448
 449                 ip = skb_flow_dissector_target(flow_dissector,
 450                                                FLOW_DISSECTOR_KEY_ENC_IP,
 451                                                target_container);
 452                 ip->tos = key->tos;
 453                 ip->ttl = key->ttl;
 454         }
 455
 456         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
 457                 struct flow_dissector_key_enc_opts *enc_opt;
 458                 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
 459                 u32 val;
 460
 461                 enc_opt = skb_flow_dissector_target(flow_dissector,
 462                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
 463                                                     target_container);
 464
 465                 if (!info->options_len)
 466                         return;
 467
 468                 enc_opt->len = info->options_len;
 469                 ip_tunnel_info_opts_get(enc_opt->data, info);
 470
 471                 ip_tunnel_set_options_present(flags);
 472                 ip_tunnel_flags_and(flags, info->key.tun_flags, flags);
 473
 474                 val = find_next_bit(flags, __IP_TUNNEL_FLAG_NUM,
 475                                     IP_TUNNEL_GENEVE_OPT_BIT);
 476                 enc_opt->dst_opt_type = val < __IP_TUNNEL_FLAG_NUM ? val : 0;
 477         }
 478 }
 479 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 480
 481 void skb_flow_dissect_hash(const struct sk_buff *skb,
 482                            struct flow_dissector *flow_dissector,
 483                            void *target_container)
 484 {
 485         struct flow_dissector_key_hash *key;
 486
 487         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH))
 488                 return;
 489
 490         key = skb_flow_dissector_target(flow_dissector,
 491                                         FLOW_DISSECTOR_KEY_HASH,
 492                                         target_container);
 493
 494         key->hash = skb_get_hash_raw(skb);
 495 }
 496 EXPORT_SYMBOL(skb_flow_dissect_hash);
 497
 498 static enum flow_dissect_ret
 499 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 500                         struct flow_dissector *flow_dissector,
 501                         void *target_container, const void *data, int nhoff,
 502                         int hlen, int lse_index, bool *entropy_label)
 503 {
 504         struct mpls_label *hdr, _hdr;
 505         u32 entry, label, bos;
 506
 507         if (!dissector_uses_key(flow_dissector,
 508                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 509             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 510                 return FLOW_DISSECT_RET_OUT_GOOD;
 511
 512         if (lse_index >= FLOW_DIS_MPLS_MAX)
 513                 return FLOW_DISSECT_RET_OUT_GOOD;
 514
 515         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 516                                    hlen, &_hdr);
 517         if (!hdr)
 518                 return FLOW_DISSECT_RET_OUT_BAD;
 519
 520         entry = ntohl(hdr->entry);
 521         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 522         bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
 523
 524         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 525                 struct flow_dissector_key_mpls *key_mpls;
 526                 struct flow_dissector_mpls_lse *lse;
 527
 528                 key_mpls = skb_flow_dissector_target(flow_dissector,
 529                                                      FLOW_DISSECTOR_KEY_MPLS,
 530                                                      target_container);
 531                 lse = &key_mpls->ls[lse_index];
 532
 533                 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
 534                 lse->mpls_bos = bos;
 535                 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
 536                 lse->mpls_label = label;
 537                 dissector_set_mpls_lse(key_mpls, lse_index);
 538         }
 539
 540         if (*entropy_label &&
 541             dissector_uses_key(flow_dissector,
 542                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 543                 struct flow_dissector_key_keyid *key_keyid;
 544
 545                 key_keyid = skb_flow_dissector_target(flow_dissector,
 546                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 547                                                       target_container);
 548                 key_keyid->keyid = cpu_to_be32(label);
 549         }
 550
 551         *entropy_label = label == MPLS_LABEL_ENTROPY;
 552
 553         return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN;
 554 }
 555
 556 static enum flow_dissect_ret
 557 __skb_flow_dissect_arp(const struct sk_buff *skb,
 558                        struct flow_dissector *flow_dissector,
 559                        void *target_container, const void *data,
 560                        int nhoff, int hlen)
 561 {
 562         struct flow_dissector_key_arp *key_arp;
 563         struct {
 564                 unsigned char ar_sha[ETH_ALEN];
 565                 unsigned char ar_sip[4];
 566                 unsigned char ar_tha[ETH_ALEN];
 567                 unsigned char ar_tip[4];
 568         } *arp_eth, _arp_eth;
 569         const struct arphdr *arp;
 570         struct arphdr _arp;
 571
 572         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 573                 return FLOW_DISSECT_RET_OUT_GOOD;
 574
 575         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 576                                    hlen, &_arp);
 577         if (!arp)
 578                 return FLOW_DISSECT_RET_OUT_BAD;
 579
 580         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 581             arp->ar_pro != htons(ETH_P_IP) ||
 582             arp->ar_hln != ETH_ALEN ||
 583             arp->ar_pln != 4 ||
 584             (arp->ar_op != htons(ARPOP_REPLY) &&
 585              arp->ar_op != htons(ARPOP_REQUEST)))
 586                 return FLOW_DISSECT_RET_OUT_BAD;
 587
 588         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 589                                        sizeof(_arp_eth), data,
 590                                        hlen, &_arp_eth);
 591         if (!arp_eth)
 592                 return FLOW_DISSECT_RET_OUT_BAD;
 593
 594         key_arp = skb_flow_dissector_target(flow_dissector,
 595                                             FLOW_DISSECTOR_KEY_ARP,
 596                                             target_container);
 597
 598         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 599         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 600
 601         /* Only store the lower byte of the opcode;
 602          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 603          */
 604         key_arp->op = ntohs(arp->ar_op) & 0xff;
 605
 606         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 607         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 608
 609         return FLOW_DISSECT_RET_OUT_GOOD;
 610 }
 611
 612 static enum flow_dissect_ret
 613 __skb_flow_dissect_cfm(const struct sk_buff *skb,
 614                        struct flow_dissector *flow_dissector,
 615                        void *target_container, const void *data,
 616                        int nhoff, int hlen)
 617 {
 618         struct flow_dissector_key_cfm *key, *hdr, _hdr;
 619
 620         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM))
 621                 return FLOW_DISSECT_RET_OUT_GOOD;
 622
 623         hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr);
 624         if (!hdr)
 625                 return FLOW_DISSECT_RET_OUT_BAD;
 626
 627         key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM,
 628                                         target_container);
 629
 630         key->mdl_ver = hdr->mdl_ver;
 631         key->opcode = hdr->opcode;
 632
 633         return FLOW_DISSECT_RET_OUT_GOOD;
 634 }
 635
 636 static enum flow_dissect_ret
 637 __skb_flow_dissect_gre(const struct sk_buff *skb,
 638                        struct flow_dissector_key_control *key_control,
 639                        struct flow_dissector *flow_dissector,
 640                        void *target_container, const void *data,
 641                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 642                        unsigned int flags)
 643 {
 644         struct flow_dissector_key_keyid *key_keyid;
 645         struct gre_base_hdr *hdr, _hdr;
 646         int offset = 0;
 647         u16 gre_ver;
 648
 649         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 650                                    data, *p_hlen, &_hdr);
 651         if (!hdr)
 652                 return FLOW_DISSECT_RET_OUT_BAD;
 653
 654         /* Only look inside GRE without routing */
 655         if (hdr->flags & GRE_ROUTING)
 656                 return FLOW_DISSECT_RET_OUT_GOOD;
 657
 658         /* Only look inside GRE for version 0 and 1 */
 659         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 660         if (gre_ver > 1)
 661                 return FLOW_DISSECT_RET_OUT_GOOD;
 662
 663         *p_proto = hdr->protocol;
 664         if (gre_ver) {
 665                 /* Version1 must be PPTP, and check the flags */
 666                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 667                         return FLOW_DISSECT_RET_OUT_GOOD;
 668         }
 669
 670         offset += sizeof(struct gre_base_hdr);
 671
 672         if (hdr->flags & GRE_CSUM)
 673                 offset += sizeof_field(struct gre_full_hdr, csum) +
 674                           sizeof_field(struct gre_full_hdr, reserved1);
 675
 676         if (hdr->flags & GRE_KEY) {
 677                 const __be32 *keyid;
 678                 __be32 _keyid;
 679
 680                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 681                                              sizeof(_keyid),
 682                                              data, *p_hlen, &_keyid);
 683                 if (!keyid)
 684                         return FLOW_DISSECT_RET_OUT_BAD;
 685
 686                 if (dissector_uses_key(flow_dissector,
 687                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 688                         key_keyid = skb_flow_dissector_target(flow_dissector,
 689                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 690                                                               target_container);
 691                         if (gre_ver == 0)
 692                                 key_keyid->keyid = *keyid;
 693                         else
 694                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 695                 }
 696                 offset += sizeof_field(struct gre_full_hdr, key);
 697         }
 698
 699         if (hdr->flags & GRE_SEQ)
 700                 offset += sizeof_field(struct pptp_gre_header, seq);
 701
 702         if (gre_ver == 0) {
 703                 if (*p_proto == htons(ETH_P_TEB)) {
 704                         const struct ethhdr *eth;
 705                         struct ethhdr _eth;
 706
 707                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 708                                                    sizeof(_eth),
 709                                                    data, *p_hlen, &_eth);
 710                         if (!eth)
 711                                 return FLOW_DISSECT_RET_OUT_BAD;
 712                         *p_proto = eth->h_proto;
 713                         offset += sizeof(*eth);
 714
 715                         /* Cap headers that we access via pointers at the
 716                          * end of the Ethernet header as our maximum alignment
 717                          * at that point is only 2 bytes.
 718                          */
 719                         if (NET_IP_ALIGN)
 720                                 *p_hlen = *p_nhoff + offset;
 721                 }
 722         } else { /* version 1, must be PPTP */
 723                 u8 _ppp_hdr[PPP_HDRLEN];
 724                 u8 *ppp_hdr;
 725
 726                 if (hdr->flags & GRE_ACK)
 727                         offset += sizeof_field(struct pptp_gre_header, ack);
 728
 729                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 730                                                sizeof(_ppp_hdr),
 731                                                data, *p_hlen, _ppp_hdr);
 732                 if (!ppp_hdr)
 733                         return FLOW_DISSECT_RET_OUT_BAD;
 734
 735                 switch (PPP_PROTOCOL(ppp_hdr)) {
 736                 case PPP_IP:
 737                         *p_proto = htons(ETH_P_IP);
 738                         break;
 739                 case PPP_IPV6:
 740                         *p_proto = htons(ETH_P_IPV6);
 741                         break;
 742                 default:
 743                         /* Could probably catch some more like MPLS */
 744                         break;
 745                 }
 746
 747                 offset += PPP_HDRLEN;
 748         }
 749
 750         *p_nhoff += offset;
 751         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 752         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 753                 return FLOW_DISSECT_RET_OUT_GOOD;
 754
 755         return FLOW_DISSECT_RET_PROTO_AGAIN;
 756 }
 757
 758 /**
 759  * __skb_flow_dissect_batadv() - dissect batman-adv header
 760  * @skb: sk_buff to with the batman-adv header
 761  * @key_control: flow dissectors control key
 762  * @data: raw buffer pointer to the packet, if NULL use skb->data
 763  * @p_proto: pointer used to update the protocol to process next
 764  * @p_nhoff: pointer used to update inner network header offset
 765  * @hlen: packet header length
 766  * @flags: any combination of FLOW_DISSECTOR_F_*
 767  *
 768  * ETH_P_BATMAN packets are tried to be dissected. Only
 769  * &struct batadv_unicast packets are actually processed because they contain an
 770  * inner ethernet header and are usually followed by actual network header. This
 771  * allows the flow dissector to continue processing the packet.
 772  *
 773  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 774  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 775  *  otherwise FLOW_DISSECT_RET_OUT_BAD
 776  */
 777 static enum flow_dissect_ret
 778 __skb_flow_dissect_batadv(const struct sk_buff *skb,
 779                           struct flow_dissector_key_control *key_control,
 780                           const void *data, __be16 *p_proto, int *p_nhoff,
 781                           int hlen, unsigned int flags)
 782 {
 783         struct {
 784                 struct batadv_unicast_packet batadv_unicast;
 785                 struct ethhdr eth;
 786         } *hdr, _hdr;
 787
 788         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 789                                    &_hdr);
 790         if (!hdr)
 791                 return FLOW_DISSECT_RET_OUT_BAD;
 792
 793         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 794                 return FLOW_DISSECT_RET_OUT_BAD;
 795
 796         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 797                 return FLOW_DISSECT_RET_OUT_BAD;
 798
 799         *p_proto = hdr->eth.h_proto;
 800         *p_nhoff += sizeof(*hdr);
 801
 802         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 803         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 804                 return FLOW_DISSECT_RET_OUT_GOOD;
 805
 806         return FLOW_DISSECT_RET_PROTO_AGAIN;
 807 }
 808
 809 static void
 810 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 811                        struct flow_dissector *flow_dissector,
 812                        void *target_container, const void *data,
 813                        int thoff, int hlen)
 814 {
 815         struct flow_dissector_key_tcp *key_tcp;
 816         struct tcphdr *th, _th;
 817
 818         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 819                 return;
 820
 821         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 822         if (!th)
 823                 return;
 824
 825         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 826                 return;
 827
 828         key_tcp = skb_flow_dissector_target(flow_dissector,
 829                                             FLOW_DISSECTOR_KEY_TCP,
 830                                             target_container);
 831         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 832 }
 833
 834 static void
 835 __skb_flow_dissect_ports(const struct sk_buff *skb,
 836                          struct flow_dissector *flow_dissector,
 837                          void *target_container, const void *data,
 838                          int nhoff, u8 ip_proto, int hlen)
 839 {
 840         enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX;
 841         struct flow_dissector_key_ports *key_ports;
 842
 843         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
 844                 dissector_ports = FLOW_DISSECTOR_KEY_PORTS;
 845         else if (dissector_uses_key(flow_dissector,
 846                                     FLOW_DISSECTOR_KEY_PORTS_RANGE))
 847                 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE;
 848
 849         if (dissector_ports == FLOW_DISSECTOR_KEY_MAX)
 850                 return;
 851
 852         key_ports = skb_flow_dissector_target(flow_dissector,
 853                                               dissector_ports,
 854                                               target_container);
 855         key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 856                                                 data, hlen);
 857 }
 858
 859 static void
 860 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 861                         struct flow_dissector *flow_dissector,
 862                         void *target_container, const void *data,
 863                         const struct iphdr *iph)
 864 {
 865         struct flow_dissector_key_ip *key_ip;
 866
 867         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 868                 return;
 869
 870         key_ip = skb_flow_dissector_target(flow_dissector,
 871                                            FLOW_DISSECTOR_KEY_IP,
 872                                            target_container);
 873         key_ip->tos = iph->tos;
 874         key_ip->ttl = iph->ttl;
 875 }
 876
 877 static void
 878 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 879                         struct flow_dissector *flow_dissector,
 880                         void *target_container, const void *data,
 881                         const struct ipv6hdr *iph)
 882 {
 883         struct flow_dissector_key_ip *key_ip;
 884
 885         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 886                 return;
 887
 888         key_ip = skb_flow_dissector_target(flow_dissector,
 889                                            FLOW_DISSECTOR_KEY_IP,
 890                                            target_container);
 891         key_ip->tos = ipv6_get_dsfield(iph);
 892         key_ip->ttl = iph->hop_limit;
 893 }
 894
 895 /* Maximum number of protocol headers that can be parsed in
 896  * __skb_flow_dissect
 897  */
 898 #define MAX_FLOW_DISSECT_HDRS   15
 899
 900 static bool skb_flow_dissect_allowed(int *num_hdrs)
 901 {
 902         ++*num_hdrs;
 903
 904         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 905 }
 906
 907 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
 908                                      struct flow_dissector *flow_dissector,
 909                                      void *target_container)
 910 {
 911         struct flow_dissector_key_ports *key_ports = NULL;
 912         struct flow_dissector_key_control *key_control;
 913         struct flow_dissector_key_basic *key_basic;
 914         struct flow_dissector_key_addrs *key_addrs;
 915         struct flow_dissector_key_tags *key_tags;
 916
 917         key_control = skb_flow_dissector_target(flow_dissector,
 918                                                 FLOW_DISSECTOR_KEY_CONTROL,
 919                                                 target_container);
 920         key_control->thoff = flow_keys->thoff;
 921         if (flow_keys->is_frag)
 922                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 923         if (flow_keys->is_first_frag)
 924                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 925         if (flow_keys->is_encap)
 926                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 927
 928         key_basic = skb_flow_dissector_target(flow_dissector,
 929                                               FLOW_DISSECTOR_KEY_BASIC,
 930                                               target_container);
 931         key_basic->n_proto = flow_keys->n_proto;
 932         key_basic->ip_proto = flow_keys->ip_proto;
 933
 934         if (flow_keys->addr_proto == ETH_P_IP &&
 935             dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 936                 key_addrs = skb_flow_dissector_target(flow_dissector,
 937                                                       FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 938                                                       target_container);
 939                 key_addrs->v4addrs.src = flow_keys->ipv4_src;
 940                 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
 941                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 942         } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
 943                    dissector_uses_key(flow_dissector,
 944                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 945                 key_addrs = skb_flow_dissector_target(flow_dissector,
 946                                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 947                                                       target_container);
 948                 memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src,
 949                        sizeof(key_addrs->v6addrs.src));
 950                 memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst,
 951                        sizeof(key_addrs->v6addrs.dst));
 952                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 953         }
 954
 955         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
 956                 key_ports = skb_flow_dissector_target(flow_dissector,
 957                                                       FLOW_DISSECTOR_KEY_PORTS,
 958                                                       target_container);
 959         else if (dissector_uses_key(flow_dissector,
 960                                     FLOW_DISSECTOR_KEY_PORTS_RANGE))
 961                 key_ports = skb_flow_dissector_target(flow_dissector,
 962                                                       FLOW_DISSECTOR_KEY_PORTS_RANGE,
 963                                                       target_container);
 964
 965         if (key_ports) {
 966                 key_ports->src = flow_keys->sport;
 967                 key_ports->dst = flow_keys->dport;
 968         }
 969
 970         if (dissector_uses_key(flow_dissector,
 971                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 972                 key_tags = skb_flow_dissector_target(flow_dissector,
 973                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 974                                                      target_container);
 975                 key_tags->flow_label = ntohl(flow_keys->flow_label);
 976         }
 977 }
 978
 979 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
 980                      __be16 proto, int nhoff, int hlen, unsigned int flags)
 981 {
 982         struct bpf_flow_keys *flow_keys = ctx->flow_keys;
 983         u32 result;
 984
 985         /* Pass parameters to the BPF program */
 986         memset(flow_keys, 0, sizeof(*flow_keys));
 987         flow_keys->n_proto = proto;
 988         flow_keys->nhoff = nhoff;
 989         flow_keys->thoff = flow_keys->nhoff;
 990
 991         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
 992                      (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
 993         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
 994                      (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 995         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
 996                      (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
 997         flow_keys->flags = flags;
 998
 999         result = bpf_prog_run_pin_on_cpu(prog, ctx);
1000
1001         flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
1002         flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
1003                                    flow_keys->nhoff, hlen);
1004
1005         return result;
1006 }
1007
1008 static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr)
1009 {
1010         return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0;
1011 }
1012
1013 /**
1014  * __skb_flow_dissect - extract the flow_keys struct and return it
1015  * @net: associated network namespace, derived from @skb if NULL
1016  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
1017  * @flow_dissector: list of keys to dissect
1018  * @target_container: target structure to put dissected values into
1019  * @data: raw buffer pointer to the packet, if NULL use skb->data
1020  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
1021  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
1022  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
1023  * @flags: flags that control the dissection process, e.g.
1024  *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
1025  *
1026  * The function will try to retrieve individual keys into target specified
1027  * by flow_dissector from either the skbuff or a raw buffer specified by the
1028  * rest parameters.
1029  *
1030  * Caller must take care of zeroing target container memory.
1031  */
1032 bool __skb_flow_dissect(const struct net *net,
1033                         const struct sk_buff *skb,
1034                         struct flow_dissector *flow_dissector,
1035                         void *target_container, const void *data,
1036                         __be16 proto, int nhoff, int hlen, unsigned int flags)
1037 {
1038         struct flow_dissector_key_control *key_control;
1039         struct flow_dissector_key_basic *key_basic;
1040         struct flow_dissector_key_addrs *key_addrs;
1041         struct flow_dissector_key_tags *key_tags;
1042         struct flow_dissector_key_vlan *key_vlan;
1043         enum flow_dissect_ret fdret;
1044         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
1045         bool mpls_el = false;
1046         int mpls_lse = 0;
1047         int num_hdrs = 0;
1048         u8 ip_proto = 0;
1049         bool ret;
1050
1051         if (!data) {
1052                 data = skb->data;
1053                 proto = skb_vlan_tag_present(skb) ?
1054                          skb->vlan_proto : skb->protocol;
1055                 nhoff = skb_network_offset(skb);
1056                 hlen = skb_headlen(skb);
1057 #if IS_ENABLED(CONFIG_NET_DSA)
1058                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
1059                              proto == htons(ETH_P_XDSA))) {
1060                         struct metadata_dst *md_dst = skb_metadata_dst(skb);
1061                         const struct dsa_device_ops *ops;
1062                         int offset = 0;
1063
1064                         ops = skb->dev->dsa_ptr->tag_ops;
1065                         /* Only DSA header taggers break flow dissection */
1066                         if (ops->needed_headroom &&
1067                             (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
1068                                 if (ops->flow_dissect)
1069                                         ops->flow_dissect(skb, &proto, &offset);
1070                                 else
1071                                         dsa_tag_generic_flow_dissect(skb,
1072                                                                      &proto,
1073                                                                      &offset);
1074                                 hlen -= offset;
1075                                 nhoff += offset;
1076                         }
1077                 }
1078 #endif
1079         }
1080
1081         /* It is ensured by skb_flow_dissector_init() that control key will
1082          * be always present.
1083          */
1084         key_control = skb_flow_dissector_target(flow_dissector,
1085                                                 FLOW_DISSECTOR_KEY_CONTROL,
1086                                                 target_container);
1087
1088         /* It is ensured by skb_flow_dissector_init() that basic key will
1089          * be always present.
1090          */
1091         key_basic = skb_flow_dissector_target(flow_dissector,
1092                                               FLOW_DISSECTOR_KEY_BASIC,
1093                                               target_container);
1094
1095         if (skb) {
1096                 if (!net) {
1097                         if (skb->dev)
1098                                 net = dev_net(skb->dev);
1099                         else if (skb->sk)
1100                                 net = sock_net(skb->sk);
1101                 }
1102         }
1103
1104         WARN_ON_ONCE(!net);
1105         if (net) {
1106                 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
1107                 struct bpf_prog_array *run_array;
1108
1109                 rcu_read_lock();
1110                 run_array = rcu_dereference(init_net.bpf.run_array[type]);
1111                 if (!run_array)
1112                         run_array = rcu_dereference(net->bpf.run_array[type]);
1113
1114                 if (run_array) {
1115                         struct bpf_flow_keys flow_keys;
1116                         struct bpf_flow_dissector ctx = {
1117                                 .flow_keys = &flow_keys,
1118                                 .data = data,
1119                                 .data_end = data + hlen,
1120                         };
1121                         __be16 n_proto = proto;
1122                         struct bpf_prog *prog;
1123                         u32 result;
1124
1125                         if (skb) {
1126                                 ctx.skb = skb;
1127                                 /* we can't use 'proto' in the skb case
1128                                  * because it might be set to skb->vlan_proto
1129                                  * which has been pulled from the data
1130                                  */
1131                                 n_proto = skb->protocol;
1132                         }
1133
1134                         prog = READ_ONCE(run_array->items[0].prog);
1135                         result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,
1136                                                   hlen, flags);
1137                         if (result == BPF_FLOW_DISSECTOR_CONTINUE)
1138                                 goto dissect_continue;
1139                         __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1140                                                  target_container);
1141                         rcu_read_unlock();
1142                         return result == BPF_OK;
1143                 }
1144 dissect_continue:
1145                 rcu_read_unlock();
1146         }
1147
1148         if (dissector_uses_key(flow_dissector,
1149                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1150                 struct ethhdr *eth = eth_hdr(skb);
1151                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
1152
1153                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1154                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
1155                                                           target_container);
1156                 memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs));
1157         }
1158
1159         if (dissector_uses_key(flow_dissector,
1160                                FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) {
1161                 struct flow_dissector_key_num_of_vlans *key_num_of_vlans;
1162
1163                 key_num_of_vlans = skb_flow_dissector_target(flow_dissector,
1164                                                              FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1165                                                              target_container);
1166                 key_num_of_vlans->num_of_vlans = 0;
1167         }
1168
1169 proto_again:
1170         fdret = FLOW_DISSECT_RET_CONTINUE;
1171
1172         switch (proto) {
1173         case htons(ETH_P_IP): {
1174                 const struct iphdr *iph;
1175                 struct iphdr _iph;
1176
1177                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1178                 if (!iph || iph->ihl < 5) {
1179                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1180                         break;
1181                 }
1182
1183                 nhoff += iph->ihl * 4;
1184
1185                 ip_proto = iph->protocol;
1186
1187                 if (dissector_uses_key(flow_dissector,
1188                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1189                         key_addrs = skb_flow_dissector_target(flow_dissector,
1190                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1191                                                               target_container);
1192
1193                         memcpy(&key_addrs->v4addrs.src, &iph->saddr,
1194                                sizeof(key_addrs->v4addrs.src));
1195                         memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
1196                                sizeof(key_addrs->v4addrs.dst));
1197                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1198                 }
1199
1200                 __skb_flow_dissect_ipv4(skb, flow_dissector,
1201                                         target_container, data, iph);
1202
1203                 if (ip_is_fragment(iph)) {
1204                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1205
1206                         if (iph->frag_off & htons(IP_OFFSET)) {
1207                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1208                                 break;
1209                         } else {
1210                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1211                                 if (!(flags &
1212                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1213                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1214                                         break;
1215                                 }
1216                         }
1217                 }
1218
1219                 break;
1220         }
1221         case htons(ETH_P_IPV6): {
1222                 const struct ipv6hdr *iph;
1223                 struct ipv6hdr _iph;
1224
1225                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1226                 if (!iph) {
1227                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1228                         break;
1229                 }
1230
1231                 ip_proto = iph->nexthdr;
1232                 nhoff += sizeof(struct ipv6hdr);
1233
1234                 if (dissector_uses_key(flow_dissector,
1235                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1236                         key_addrs = skb_flow_dissector_target(flow_dissector,
1237                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1238                                                               target_container);
1239
1240                         memcpy(&key_addrs->v6addrs.src, &iph->saddr,
1241                                sizeof(key_addrs->v6addrs.src));
1242                         memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
1243                                sizeof(key_addrs->v6addrs.dst));
1244                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1245                 }
1246
1247                 if ((dissector_uses_key(flow_dissector,
1248                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1249                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1250                     ip6_flowlabel(iph)) {
1251                         __be32 flow_label = ip6_flowlabel(iph);
1252
1253                         if (dissector_uses_key(flow_dissector,
1254                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1255                                 key_tags = skb_flow_dissector_target(flow_dissector,
1256                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
1257                                                                      target_container);
1258                                 key_tags->flow_label = ntohl(flow_label);
1259                         }
1260                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1261                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1262                                 break;
1263                         }
1264                 }
1265
1266                 __skb_flow_dissect_ipv6(skb, flow_dissector,
1267                                         target_container, data, iph);
1268
1269                 break;
1270         }
1271         case htons(ETH_P_8021AD):
1272         case htons(ETH_P_8021Q): {
1273                 const struct vlan_hdr *vlan = NULL;
1274                 struct vlan_hdr _vlan;
1275                 __be16 saved_vlan_tpid = proto;
1276
1277                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1278                     skb && skb_vlan_tag_present(skb)) {
1279                         proto = skb->protocol;
1280                 } else {
1281                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1282                                                     data, hlen, &_vlan);
1283                         if (!vlan) {
1284                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1285                                 break;
1286                         }
1287
1288                         proto = vlan->h_vlan_encapsulated_proto;
1289                         nhoff += sizeof(*vlan);
1290                 }
1291
1292                 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) &&
1293                     !(key_control->flags & FLOW_DIS_ENCAPSULATION)) {
1294                         struct flow_dissector_key_num_of_vlans *key_nvs;
1295
1296                         key_nvs = skb_flow_dissector_target(flow_dissector,
1297                                                             FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1298                                                             target_container);
1299                         key_nvs->num_of_vlans++;
1300                 }
1301
1302                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1303                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1304                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1305                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1306                 } else {
1307                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1308                         break;
1309                 }
1310
1311                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1312                         key_vlan = skb_flow_dissector_target(flow_dissector,
1313                                                              dissector_vlan,
1314                                                              target_container);
1315
1316                         if (!vlan) {
1317                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1318                                 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1319                         } else {
1320                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1321                                         VLAN_VID_MASK;
1322                                 key_vlan->vlan_priority =
1323                                         (ntohs(vlan->h_vlan_TCI) &
1324                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1325                         }
1326                         key_vlan->vlan_tpid = saved_vlan_tpid;
1327                         key_vlan->vlan_eth_type = proto;
1328                 }
1329
1330                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1331                 break;
1332         }
1333         case htons(ETH_P_PPP_SES): {
1334                 struct {
1335                         struct pppoe_hdr hdr;
1336                         __be16 proto;
1337                 } *hdr, _hdr;
1338                 u16 ppp_proto;
1339
1340                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1341                 if (!hdr) {
1342                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1343                         break;
1344                 }
1345
1346                 if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) {
1347                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1348                         break;
1349                 }
1350
1351                 /* least significant bit of the most significant octet
1352                  * indicates if protocol field was compressed
1353                  */
1354                 ppp_proto = ntohs(hdr->proto);
1355                 if (ppp_proto & 0x0100) {
1356                         ppp_proto = ppp_proto >> 8;
1357                         nhoff += PPPOE_SES_HLEN - 1;
1358                 } else {
1359                         nhoff += PPPOE_SES_HLEN;
1360                 }
1361
1362                 if (ppp_proto == PPP_IP) {
1363                         proto = htons(ETH_P_IP);
1364                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1365                 } else if (ppp_proto == PPP_IPV6) {
1366                         proto = htons(ETH_P_IPV6);
1367                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1368                 } else if (ppp_proto == PPP_MPLS_UC) {
1369                         proto = htons(ETH_P_MPLS_UC);
1370                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1371                 } else if (ppp_proto == PPP_MPLS_MC) {
1372                         proto = htons(ETH_P_MPLS_MC);
1373                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1374                 } else if (ppp_proto_is_valid(ppp_proto)) {
1375                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1376                 } else {
1377                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1378                         break;
1379                 }
1380
1381                 if (dissector_uses_key(flow_dissector,
1382                                        FLOW_DISSECTOR_KEY_PPPOE)) {
1383                         struct flow_dissector_key_pppoe *key_pppoe;
1384
1385                         key_pppoe = skb_flow_dissector_target(flow_dissector,
1386                                                               FLOW_DISSECTOR_KEY_PPPOE,
1387                                                               target_container);
1388                         key_pppoe->session_id = hdr->hdr.sid;
1389                         key_pppoe->ppp_proto = htons(ppp_proto);
1390                         key_pppoe->type = htons(ETH_P_PPP_SES);
1391                 }
1392                 break;
1393         }
1394         case htons(ETH_P_TIPC): {
1395                 struct tipc_basic_hdr *hdr, _hdr;
1396
1397                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1398                                            data, hlen, &_hdr);
1399                 if (!hdr) {
1400                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1401                         break;
1402                 }
1403
1404                 if (dissector_uses_key(flow_dissector,
1405                                        FLOW_DISSECTOR_KEY_TIPC)) {
1406                         key_addrs = skb_flow_dissector_target(flow_dissector,
1407                                                               FLOW_DISSECTOR_KEY_TIPC,
1408                                                               target_container);
1409                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1410                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1411                 }
1412                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1413                 break;
1414         }
1415
1416         case htons(ETH_P_MPLS_UC):
1417         case htons(ETH_P_MPLS_MC):
1418                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1419                                                 target_container, data,
1420                                                 nhoff, hlen, mpls_lse,
1421                                                 &mpls_el);
1422                 nhoff += sizeof(struct mpls_label);
1423                 mpls_lse++;
1424                 break;
1425         case htons(ETH_P_FCOE):
1426                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1427                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1428                         break;
1429                 }
1430
1431                 nhoff += FCOE_HEADER_LEN;
1432                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1433                 break;
1434
1435         case htons(ETH_P_ARP):
1436         case htons(ETH_P_RARP):
1437                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1438                                                target_container, data,
1439                                                nhoff, hlen);
1440                 break;
1441
1442         case htons(ETH_P_BATMAN):
1443                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1444                                                   &proto, &nhoff, hlen, flags);
1445                 break;
1446
1447         case htons(ETH_P_1588): {
1448                 struct ptp_header *hdr, _hdr;
1449
1450                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
1451                                            hlen, &_hdr);
1452                 if (!hdr) {
1453                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1454                         break;
1455                 }
1456
1457                 nhoff += sizeof(struct ptp_header);
1458                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1459                 break;
1460         }
1461
1462         case htons(ETH_P_PRP):
1463         case htons(ETH_P_HSR): {
1464                 struct hsr_tag *hdr, _hdr;
1465
1466                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen,
1467                                            &_hdr);
1468                 if (!hdr) {
1469                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1470                         break;
1471                 }
1472
1473                 proto = hdr->encap_proto;
1474                 nhoff += HSR_HLEN;
1475                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1476                 break;
1477         }
1478
1479         case htons(ETH_P_CFM):
1480                 fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
1481                                                target_container, data,
1482                                                nhoff, hlen);
1483                 break;
1484
1485         default:
1486                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1487                 break;
1488         }
1489
1490         /* Process result of proto processing */
1491         switch (fdret) {
1492         case FLOW_DISSECT_RET_OUT_GOOD:
1493                 goto out_good;
1494         case FLOW_DISSECT_RET_PROTO_AGAIN:
1495                 if (skb_flow_dissect_allowed(&num_hdrs))
1496                         goto proto_again;
1497                 goto out_good;
1498         case FLOW_DISSECT_RET_CONTINUE:
1499         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1500                 break;
1501         case FLOW_DISSECT_RET_OUT_BAD:
1502         default:
1503                 goto out_bad;
1504         }
1505
1506 ip_proto_again:
1507         fdret = FLOW_DISSECT_RET_CONTINUE;
1508
1509         switch (ip_proto) {
1510         case IPPROTO_GRE:
1511                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1512                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1513                         break;
1514                 }
1515
1516                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1517                                                target_container, data,
1518                                                &proto, &nhoff, &hlen, flags);
1519                 break;
1520
1521         case NEXTHDR_HOP:
1522         case NEXTHDR_ROUTING:
1523         case NEXTHDR_DEST: {
1524                 u8 _opthdr[2], *opthdr;
1525
1526                 if (proto != htons(ETH_P_IPV6))
1527                         break;
1528
1529                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1530                                               data, hlen, &_opthdr);
1531                 if (!opthdr) {
1532                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1533                         break;
1534                 }
1535
1536                 ip_proto = opthdr[0];
1537                 nhoff += (opthdr[1] + 1) << 3;
1538
1539                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1540                 break;
1541         }
1542         case NEXTHDR_FRAGMENT: {
1543                 struct frag_hdr _fh, *fh;
1544
1545                 if (proto != htons(ETH_P_IPV6))
1546                         break;
1547
1548                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1549                                           data, hlen, &_fh);
1550
1551                 if (!fh) {
1552                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1553                         break;
1554                 }
1555
1556                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1557
1558                 nhoff += sizeof(_fh);
1559                 ip_proto = fh->nexthdr;
1560
1561                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1562                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
1563                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1564                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1565                                 break;
1566                         }
1567                 }
1568
1569                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1570                 break;
1571         }
1572         case IPPROTO_IPIP:
1573                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1574                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1575                         break;
1576                 }
1577
1578                 proto = htons(ETH_P_IP);
1579
1580                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1581                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1582                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1583                         break;
1584                 }
1585
1586                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1587                 break;
1588
1589         case IPPROTO_IPV6:
1590                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1591                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1592                         break;
1593                 }
1594
1595                 proto = htons(ETH_P_IPV6);
1596
1597                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1598                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1599                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1600                         break;
1601                 }
1602
1603                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1604                 break;
1605
1606
1607         case IPPROTO_MPLS:
1608                 proto = htons(ETH_P_MPLS_UC);
1609                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1610                 break;
1611
1612         case IPPROTO_TCP:
1613                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1614                                        data, nhoff, hlen);
1615                 break;
1616
1617         case IPPROTO_ICMP:
1618         case IPPROTO_ICMPV6:
1619                 __skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1620                                         data, nhoff, hlen);
1621                 break;
1622         case IPPROTO_L2TP:
1623                 __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container,
1624                                           data, nhoff, hlen);
1625                 break;
1626         case IPPROTO_ESP:
1627                 __skb_flow_dissect_esp(skb, flow_dissector, target_container,
1628                                        data, nhoff, hlen);
1629                 break;
1630         case IPPROTO_AH:
1631                 __skb_flow_dissect_ah(skb, flow_dissector, target_container,
1632                                       data, nhoff, hlen);
1633                 break;
1634         default:
1635                 break;
1636         }
1637
1638         if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT))
1639                 __skb_flow_dissect_ports(skb, flow_dissector, target_container,
1640                                          data, nhoff, ip_proto, hlen);
1641
1642         /* Process result of IP proto processing */
1643         switch (fdret) {
1644         case FLOW_DISSECT_RET_PROTO_AGAIN:
1645                 if (skb_flow_dissect_allowed(&num_hdrs))
1646                         goto proto_again;
1647                 break;
1648         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1649                 if (skb_flow_dissect_allowed(&num_hdrs))
1650                         goto ip_proto_again;
1651                 break;
1652         case FLOW_DISSECT_RET_OUT_GOOD:
1653         case FLOW_DISSECT_RET_CONTINUE:
1654                 break;
1655         case FLOW_DISSECT_RET_OUT_BAD:
1656         default:
1657                 goto out_bad;
1658         }
1659
1660 out_good:
1661         ret = true;
1662
1663 out:
1664         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1665         key_basic->n_proto = proto;
1666         key_basic->ip_proto = ip_proto;
1667
1668         return ret;
1669
1670 out_bad:
1671         ret = false;
1672         goto out;
1673 }
1674 EXPORT_SYMBOL(__skb_flow_dissect);
1675
1676 static siphash_aligned_key_t hashrnd;
1677 static __always_inline void __flow_hash_secret_init(void)
1678 {
1679         net_get_random_once(&hashrnd, sizeof(hashrnd));
1680 }
1681
1682 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1683 {
1684         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1685         return &flow->FLOW_KEYS_HASH_START_FIELD;
1686 }
1687
1688 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1689 {
1690         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1691
1692         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1693
1694         switch (flow->control.addr_type) {
1695         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1696                 diff -= sizeof(flow->addrs.v4addrs);
1697                 break;
1698         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1699                 diff -= sizeof(flow->addrs.v6addrs);
1700                 break;
1701         case FLOW_DISSECTOR_KEY_TIPC:
1702                 diff -= sizeof(flow->addrs.tipckey);
1703                 break;
1704         }
1705         return sizeof(*flow) - diff;
1706 }
1707
1708 __be32 flow_get_u32_src(const struct flow_keys *flow)
1709 {
1710         switch (flow->control.addr_type) {
1711         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1712                 return flow->addrs.v4addrs.src;
1713         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1714                 return (__force __be32)ipv6_addr_hash(
1715                         &flow->addrs.v6addrs.src);
1716         case FLOW_DISSECTOR_KEY_TIPC:
1717                 return flow->addrs.tipckey.key;
1718         default:
1719                 return 0;
1720         }
1721 }
1722 EXPORT_SYMBOL(flow_get_u32_src);
1723
1724 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1725 {
1726         switch (flow->control.addr_type) {
1727         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1728                 return flow->addrs.v4addrs.dst;
1729         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1730                 return (__force __be32)ipv6_addr_hash(
1731                         &flow->addrs.v6addrs.dst);
1732         default:
1733                 return 0;
1734         }
1735 }
1736 EXPORT_SYMBOL(flow_get_u32_dst);
1737
1738 /* Sort the source and destination IP and the ports,
1739  * to have consistent hash within the two directions
1740  */
1741 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1742 {
1743         int addr_diff, i;
1744
1745         switch (keys->control.addr_type) {
1746         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1747                 if ((__force u32)keys->addrs.v4addrs.dst <
1748                     (__force u32)keys->addrs.v4addrs.src)
1749                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1750
1751                 if ((__force u16)keys->ports.dst <
1752                     (__force u16)keys->ports.src) {
1753                         swap(keys->ports.src, keys->ports.dst);
1754                 }
1755                 break;
1756         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1757                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1758                                    &keys->addrs.v6addrs.src,
1759                                    sizeof(keys->addrs.v6addrs.dst));
1760                 if (addr_diff < 0) {
1761                         for (i = 0; i < 4; i++)
1762                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1763                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1764                 }
1765                 if ((__force u16)keys->ports.dst <
1766                     (__force u16)keys->ports.src) {
1767                         swap(keys->ports.src, keys->ports.dst);
1768                 }
1769                 break;
1770         }
1771 }
1772
1773 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1774                                         const siphash_key_t *keyval)
1775 {
1776         u32 hash;
1777
1778         __flow_hash_consistentify(keys);
1779
1780         hash = siphash(flow_keys_hash_start(keys),
1781                        flow_keys_hash_length(keys), keyval);
1782         if (!hash)
1783                 hash = 1;
1784
1785         return hash;
1786 }
1787
1788 u32 flow_hash_from_keys(struct flow_keys *keys)
1789 {
1790         __flow_hash_secret_init();
1791         return __flow_hash_from_keys(keys, &hashrnd);
1792 }
1793 EXPORT_SYMBOL(flow_hash_from_keys);
1794
1795 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1796                                   struct flow_keys *keys,
1797                                   const siphash_key_t *keyval)
1798 {
1799         skb_flow_dissect_flow_keys(skb, keys,
1800                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1801
1802         return __flow_hash_from_keys(keys, keyval);
1803 }
1804
1805 struct _flow_keys_digest_data {
1806         __be16  n_proto;
1807         u8      ip_proto;
1808         u8      padding;
1809         __be32  ports;
1810         __be32  src;
1811         __be32  dst;
1812 };
1813
1814 void make_flow_keys_digest(struct flow_keys_digest *digest,
1815                            const struct flow_keys *flow)
1816 {
1817         struct _flow_keys_digest_data *data =
1818             (struct _flow_keys_digest_data *)digest;
1819
1820         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1821
1822         memset(digest, 0, sizeof(*digest));
1823
1824         data->n_proto = flow->basic.n_proto;
1825         data->ip_proto = flow->basic.ip_proto;
1826         data->ports = flow->ports.ports;
1827         data->src = flow->addrs.v4addrs.src;
1828         data->dst = flow->addrs.v4addrs.dst;
1829 }
1830 EXPORT_SYMBOL(make_flow_keys_digest);
1831
1832 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1833
1834 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1835 {
1836         struct flow_keys keys;
1837
1838         __flow_hash_secret_init();
1839
1840         memset(&keys, 0, sizeof(keys));
1841         __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1842                            &keys, NULL, 0, 0, 0, 0);
1843
1844         return __flow_hash_from_keys(&keys, &hashrnd);
1845 }
1846 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1847
1848 /**
1849  * __skb_get_hash: calculate a flow hash
1850  * @skb: sk_buff to calculate flow hash from
1851  *
1852  * This function calculates a flow hash based on src/dst addresses
1853  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1854  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1855  * if hash is a canonical 4-tuple hash over transport ports.
1856  */
1857 void __skb_get_hash(struct sk_buff *skb)
1858 {
1859         struct flow_keys keys;
1860         u32 hash;
1861
1862         __flow_hash_secret_init();
1863
1864         hash = ___skb_get_hash(skb, &keys, &hashrnd);
1865
1866         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1867 }
1868 EXPORT_SYMBOL(__skb_get_hash);
1869
1870 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1871                            const siphash_key_t *perturb)
1872 {
1873         struct flow_keys keys;
1874
1875         return ___skb_get_hash(skb, &keys, perturb);
1876 }
1877 EXPORT_SYMBOL(skb_get_hash_perturb);
1878
1879 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1880                    const struct flow_keys_basic *keys, int hlen)
1881 {
1882         u32 poff = keys->control.thoff;
1883
1884         /* skip L4 headers for fragments after the first */
1885         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1886             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1887                 return poff;
1888
1889         switch (keys->basic.ip_proto) {
1890         case IPPROTO_TCP: {
1891                 /* access doff as u8 to avoid unaligned access */
1892                 const u8 *doff;
1893                 u8 _doff;
1894
1895                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1896                                             data, hlen, &_doff);
1897                 if (!doff)
1898                         return poff;
1899
1900                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1901                 break;
1902         }
1903         case IPPROTO_UDP:
1904         case IPPROTO_UDPLITE:
1905                 poff += sizeof(struct udphdr);
1906                 break;
1907         /* For the rest, we do not really care about header
1908          * extensions at this point for now.
1909          */
1910         case IPPROTO_ICMP:
1911                 poff += sizeof(struct icmphdr);
1912                 break;
1913         case IPPROTO_ICMPV6:
1914                 poff += sizeof(struct icmp6hdr);
1915                 break;
1916         case IPPROTO_IGMP:
1917                 poff += sizeof(struct igmphdr);
1918                 break;
1919         case IPPROTO_DCCP:
1920                 poff += sizeof(struct dccp_hdr);
1921                 break;
1922         case IPPROTO_SCTP:
1923                 poff += sizeof(struct sctphdr);
1924                 break;
1925         }
1926
1927         return poff;
1928 }
1929
1930 /**
1931  * skb_get_poff - get the offset to the payload
1932  * @skb: sk_buff to get the payload offset from
1933  *
1934  * The function will get the offset to the payload as far as it could
1935  * be dissected.  The main user is currently BPF, so that we can dynamically
1936  * truncate packets without needing to push actual payload to the user
1937  * space and can analyze headers only, instead.
1938  */
1939 u32 skb_get_poff(const struct sk_buff *skb)
1940 {
1941         struct flow_keys_basic keys;
1942
1943         if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1944                                               NULL, 0, 0, 0, 0))
1945                 return 0;
1946
1947         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1948 }
1949
1950 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1951 {
1952         memset(keys, 0, sizeof(*keys));
1953
1954         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1955             sizeof(keys->addrs.v6addrs.src));
1956         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1957             sizeof(keys->addrs.v6addrs.dst));
1958         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1959         keys->ports.src = fl6->fl6_sport;
1960         keys->ports.dst = fl6->fl6_dport;
1961         keys->keyid.keyid = fl6->fl6_gre_key;
1962         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1963         keys->basic.ip_proto = fl6->flowi6_proto;
1964
1965         return flow_hash_from_keys(keys);
1966 }
1967 EXPORT_SYMBOL(__get_hash_from_flowi6);
1968
1969 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1970         {
1971                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1972                 .offset = offsetof(struct flow_keys, control),
1973         },
1974         {
1975                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1976                 .offset = offsetof(struct flow_keys, basic),
1977         },
1978         {
1979                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1980                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1981         },
1982         {
1983                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1984                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1985         },
1986         {
1987                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1988                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1989         },
1990         {
1991                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1992                 .offset = offsetof(struct flow_keys, ports),
1993         },
1994         {
1995                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1996                 .offset = offsetof(struct flow_keys, vlan),
1997         },
1998         {
1999                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
2000                 .offset = offsetof(struct flow_keys, tags),
2001         },
2002         {
2003                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
2004                 .offset = offsetof(struct flow_keys, keyid),
2005         },
2006 };
2007
2008 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
2009         {
2010                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
2011                 .offset = offsetof(struct flow_keys, control),
2012         },
2013         {
2014                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
2015                 .offset = offsetof(struct flow_keys, basic),
2016         },
2017         {
2018                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
2019                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
2020         },
2021         {
2022                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
2023                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
2024         },
2025         {
2026                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
2027                 .offset = offsetof(struct flow_keys, ports),
2028         },
2029 };
2030
2031 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
2032         {
2033                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
2034                 .offset = offsetof(struct flow_keys, control),
2035         },
2036         {
2037                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
2038                 .offset = offsetof(struct flow_keys, basic),
2039         },
2040 };
2041
2042 struct flow_dissector flow_keys_dissector __read_mostly;
2043 EXPORT_SYMBOL(flow_keys_dissector);
2044
2045 struct flow_dissector flow_keys_basic_dissector __read_mostly;
2046 EXPORT_SYMBOL(flow_keys_basic_dissector);
2047
2048 static int __init init_default_flow_dissectors(void)
2049 {
2050         skb_flow_dissector_init(&flow_keys_dissector,
2051                                 flow_keys_dissector_keys,
2052                                 ARRAY_SIZE(flow_keys_dissector_keys));
2053         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
2054                                 flow_keys_dissector_symmetric_keys,
2055                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
2056         skb_flow_dissector_init(&flow_keys_basic_dissector,
2057                                 flow_keys_basic_dissector_keys,
2058                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
2059         return 0;
2060 }
2061 core_initcall(init_default_flow_dissectors);