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
 459                 enc_opt = skb_flow_dissector_target(flow_dissector,
 460                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
 461                                                     target_container);
 462
 463                 if (info->options_len) {
 464                         enc_opt->len = info->options_len;
 465                         ip_tunnel_info_opts_get(enc_opt->data, info);
 466                         enc_opt->dst_opt_type = info->key.tun_flags &
 467                                                 TUNNEL_OPTIONS_PRESENT;
 468                 }
 469         }
 470 }
 471 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 472
 473 void skb_flow_dissect_hash(const struct sk_buff *skb,
 474                            struct flow_dissector *flow_dissector,
 475                            void *target_container)
 476 {
 477         struct flow_dissector_key_hash *key;
 478
 479         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH))
 480                 return;
 481
 482         key = skb_flow_dissector_target(flow_dissector,
 483                                         FLOW_DISSECTOR_KEY_HASH,
 484                                         target_container);
 485
 486         key->hash = skb_get_hash_raw(skb);
 487 }
 488 EXPORT_SYMBOL(skb_flow_dissect_hash);
 489
 490 static enum flow_dissect_ret
 491 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 492                         struct flow_dissector *flow_dissector,
 493                         void *target_container, const void *data, int nhoff,
 494                         int hlen, int lse_index, bool *entropy_label)
 495 {
 496         struct mpls_label *hdr, _hdr;
 497         u32 entry, label, bos;
 498
 499         if (!dissector_uses_key(flow_dissector,
 500                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 501             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 502                 return FLOW_DISSECT_RET_OUT_GOOD;
 503
 504         if (lse_index >= FLOW_DIS_MPLS_MAX)
 505                 return FLOW_DISSECT_RET_OUT_GOOD;
 506
 507         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 508                                    hlen, &_hdr);
 509         if (!hdr)
 510                 return FLOW_DISSECT_RET_OUT_BAD;
 511
 512         entry = ntohl(hdr->entry);
 513         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 514         bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
 515
 516         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 517                 struct flow_dissector_key_mpls *key_mpls;
 518                 struct flow_dissector_mpls_lse *lse;
 519
 520                 key_mpls = skb_flow_dissector_target(flow_dissector,
 521                                                      FLOW_DISSECTOR_KEY_MPLS,
 522                                                      target_container);
 523                 lse = &key_mpls->ls[lse_index];
 524
 525                 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
 526                 lse->mpls_bos = bos;
 527                 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
 528                 lse->mpls_label = label;
 529                 dissector_set_mpls_lse(key_mpls, lse_index);
 530         }
 531
 532         if (*entropy_label &&
 533             dissector_uses_key(flow_dissector,
 534                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 535                 struct flow_dissector_key_keyid *key_keyid;
 536
 537                 key_keyid = skb_flow_dissector_target(flow_dissector,
 538                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 539                                                       target_container);
 540                 key_keyid->keyid = cpu_to_be32(label);
 541         }
 542
 543         *entropy_label = label == MPLS_LABEL_ENTROPY;
 544
 545         return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN;
 546 }
 547
 548 static enum flow_dissect_ret
 549 __skb_flow_dissect_arp(const struct sk_buff *skb,
 550                        struct flow_dissector *flow_dissector,
 551                        void *target_container, const void *data,
 552                        int nhoff, int hlen)
 553 {
 554         struct flow_dissector_key_arp *key_arp;
 555         struct {
 556                 unsigned char ar_sha[ETH_ALEN];
 557                 unsigned char ar_sip[4];
 558                 unsigned char ar_tha[ETH_ALEN];
 559                 unsigned char ar_tip[4];
 560         } *arp_eth, _arp_eth;
 561         const struct arphdr *arp;
 562         struct arphdr _arp;
 563
 564         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 565                 return FLOW_DISSECT_RET_OUT_GOOD;
 566
 567         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 568                                    hlen, &_arp);
 569         if (!arp)
 570                 return FLOW_DISSECT_RET_OUT_BAD;
 571
 572         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 573             arp->ar_pro != htons(ETH_P_IP) ||
 574             arp->ar_hln != ETH_ALEN ||
 575             arp->ar_pln != 4 ||
 576             (arp->ar_op != htons(ARPOP_REPLY) &&
 577              arp->ar_op != htons(ARPOP_REQUEST)))
 578                 return FLOW_DISSECT_RET_OUT_BAD;
 579
 580         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 581                                        sizeof(_arp_eth), data,
 582                                        hlen, &_arp_eth);
 583         if (!arp_eth)
 584                 return FLOW_DISSECT_RET_OUT_BAD;
 585
 586         key_arp = skb_flow_dissector_target(flow_dissector,
 587                                             FLOW_DISSECTOR_KEY_ARP,
 588                                             target_container);
 589
 590         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 591         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 592
 593         /* Only store the lower byte of the opcode;
 594          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 595          */
 596         key_arp->op = ntohs(arp->ar_op) & 0xff;
 597
 598         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 599         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 600
 601         return FLOW_DISSECT_RET_OUT_GOOD;
 602 }
 603
 604 static enum flow_dissect_ret
 605 __skb_flow_dissect_cfm(const struct sk_buff *skb,
 606                        struct flow_dissector *flow_dissector,
 607                        void *target_container, const void *data,
 608                        int nhoff, int hlen)
 609 {
 610         struct flow_dissector_key_cfm *key, *hdr, _hdr;
 611
 612         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM))
 613                 return FLOW_DISSECT_RET_OUT_GOOD;
 614
 615         hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr);
 616         if (!hdr)
 617                 return FLOW_DISSECT_RET_OUT_BAD;
 618
 619         key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM,
 620                                         target_container);
 621
 622         key->mdl_ver = hdr->mdl_ver;
 623         key->opcode = hdr->opcode;
 624
 625         return FLOW_DISSECT_RET_OUT_GOOD;
 626 }
 627
 628 static enum flow_dissect_ret
 629 __skb_flow_dissect_gre(const struct sk_buff *skb,
 630                        struct flow_dissector_key_control *key_control,
 631                        struct flow_dissector *flow_dissector,
 632                        void *target_container, const void *data,
 633                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 634                        unsigned int flags)
 635 {
 636         struct flow_dissector_key_keyid *key_keyid;
 637         struct gre_base_hdr *hdr, _hdr;
 638         int offset = 0;
 639         u16 gre_ver;
 640
 641         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 642                                    data, *p_hlen, &_hdr);
 643         if (!hdr)
 644                 return FLOW_DISSECT_RET_OUT_BAD;
 645
 646         /* Only look inside GRE without routing */
 647         if (hdr->flags & GRE_ROUTING)
 648                 return FLOW_DISSECT_RET_OUT_GOOD;
 649
 650         /* Only look inside GRE for version 0 and 1 */
 651         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 652         if (gre_ver > 1)
 653                 return FLOW_DISSECT_RET_OUT_GOOD;
 654
 655         *p_proto = hdr->protocol;
 656         if (gre_ver) {
 657                 /* Version1 must be PPTP, and check the flags */
 658                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 659                         return FLOW_DISSECT_RET_OUT_GOOD;
 660         }
 661
 662         offset += sizeof(struct gre_base_hdr);
 663
 664         if (hdr->flags & GRE_CSUM)
 665                 offset += sizeof_field(struct gre_full_hdr, csum) +
 666                           sizeof_field(struct gre_full_hdr, reserved1);
 667
 668         if (hdr->flags & GRE_KEY) {
 669                 const __be32 *keyid;
 670                 __be32 _keyid;
 671
 672                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 673                                              sizeof(_keyid),
 674                                              data, *p_hlen, &_keyid);
 675                 if (!keyid)
 676                         return FLOW_DISSECT_RET_OUT_BAD;
 677
 678                 if (dissector_uses_key(flow_dissector,
 679                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 680                         key_keyid = skb_flow_dissector_target(flow_dissector,
 681                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 682                                                               target_container);
 683                         if (gre_ver == 0)
 684                                 key_keyid->keyid = *keyid;
 685                         else
 686                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 687                 }
 688                 offset += sizeof_field(struct gre_full_hdr, key);
 689         }
 690
 691         if (hdr->flags & GRE_SEQ)
 692                 offset += sizeof_field(struct pptp_gre_header, seq);
 693
 694         if (gre_ver == 0) {
 695                 if (*p_proto == htons(ETH_P_TEB)) {
 696                         const struct ethhdr *eth;
 697                         struct ethhdr _eth;
 698
 699                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 700                                                    sizeof(_eth),
 701                                                    data, *p_hlen, &_eth);
 702                         if (!eth)
 703                                 return FLOW_DISSECT_RET_OUT_BAD;
 704                         *p_proto = eth->h_proto;
 705                         offset += sizeof(*eth);
 706
 707                         /* Cap headers that we access via pointers at the
 708                          * end of the Ethernet header as our maximum alignment
 709                          * at that point is only 2 bytes.
 710                          */
 711                         if (NET_IP_ALIGN)
 712                                 *p_hlen = *p_nhoff + offset;
 713                 }
 714         } else { /* version 1, must be PPTP */
 715                 u8 _ppp_hdr[PPP_HDRLEN];
 716                 u8 *ppp_hdr;
 717
 718                 if (hdr->flags & GRE_ACK)
 719                         offset += sizeof_field(struct pptp_gre_header, ack);
 720
 721                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 722                                                sizeof(_ppp_hdr),
 723                                                data, *p_hlen, _ppp_hdr);
 724                 if (!ppp_hdr)
 725                         return FLOW_DISSECT_RET_OUT_BAD;
 726
 727                 switch (PPP_PROTOCOL(ppp_hdr)) {
 728                 case PPP_IP:
 729                         *p_proto = htons(ETH_P_IP);
 730                         break;
 731                 case PPP_IPV6:
 732                         *p_proto = htons(ETH_P_IPV6);
 733                         break;
 734                 default:
 735                         /* Could probably catch some more like MPLS */
 736                         break;
 737                 }
 738
 739                 offset += PPP_HDRLEN;
 740         }
 741
 742         *p_nhoff += offset;
 743         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 744         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 745                 return FLOW_DISSECT_RET_OUT_GOOD;
 746
 747         return FLOW_DISSECT_RET_PROTO_AGAIN;
 748 }
 749
 750 /**
 751  * __skb_flow_dissect_batadv() - dissect batman-adv header
 752  * @skb: sk_buff to with the batman-adv header
 753  * @key_control: flow dissectors control key
 754  * @data: raw buffer pointer to the packet, if NULL use skb->data
 755  * @p_proto: pointer used to update the protocol to process next
 756  * @p_nhoff: pointer used to update inner network header offset
 757  * @hlen: packet header length
 758  * @flags: any combination of FLOW_DISSECTOR_F_*
 759  *
 760  * ETH_P_BATMAN packets are tried to be dissected. Only
 761  * &struct batadv_unicast packets are actually processed because they contain an
 762  * inner ethernet header and are usually followed by actual network header. This
 763  * allows the flow dissector to continue processing the packet.
 764  *
 765  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 766  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 767  *  otherwise FLOW_DISSECT_RET_OUT_BAD
 768  */
 769 static enum flow_dissect_ret
 770 __skb_flow_dissect_batadv(const struct sk_buff *skb,
 771                           struct flow_dissector_key_control *key_control,
 772                           const void *data, __be16 *p_proto, int *p_nhoff,
 773                           int hlen, unsigned int flags)
 774 {
 775         struct {
 776                 struct batadv_unicast_packet batadv_unicast;
 777                 struct ethhdr eth;
 778         } *hdr, _hdr;
 779
 780         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 781                                    &_hdr);
 782         if (!hdr)
 783                 return FLOW_DISSECT_RET_OUT_BAD;
 784
 785         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 786                 return FLOW_DISSECT_RET_OUT_BAD;
 787
 788         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 789                 return FLOW_DISSECT_RET_OUT_BAD;
 790
 791         *p_proto = hdr->eth.h_proto;
 792         *p_nhoff += sizeof(*hdr);
 793
 794         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 795         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 796                 return FLOW_DISSECT_RET_OUT_GOOD;
 797
 798         return FLOW_DISSECT_RET_PROTO_AGAIN;
 799 }
 800
 801 static void
 802 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 803                        struct flow_dissector *flow_dissector,
 804                        void *target_container, const void *data,
 805                        int thoff, int hlen)
 806 {
 807         struct flow_dissector_key_tcp *key_tcp;
 808         struct tcphdr *th, _th;
 809
 810         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 811                 return;
 812
 813         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 814         if (!th)
 815                 return;
 816
 817         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 818                 return;
 819
 820         key_tcp = skb_flow_dissector_target(flow_dissector,
 821                                             FLOW_DISSECTOR_KEY_TCP,
 822                                             target_container);
 823         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 824 }
 825
 826 static void
 827 __skb_flow_dissect_ports(const struct sk_buff *skb,
 828                          struct flow_dissector *flow_dissector,
 829                          void *target_container, const void *data,
 830                          int nhoff, u8 ip_proto, int hlen)
 831 {
 832         enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX;
 833         struct flow_dissector_key_ports *key_ports;
 834
 835         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
 836                 dissector_ports = FLOW_DISSECTOR_KEY_PORTS;
 837         else if (dissector_uses_key(flow_dissector,
 838                                     FLOW_DISSECTOR_KEY_PORTS_RANGE))
 839                 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE;
 840
 841         if (dissector_ports == FLOW_DISSECTOR_KEY_MAX)
 842                 return;
 843
 844         key_ports = skb_flow_dissector_target(flow_dissector,
 845                                               dissector_ports,
 846                                               target_container);
 847         key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 848                                                 data, hlen);
 849 }
 850
 851 static void
 852 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 853                         struct flow_dissector *flow_dissector,
 854                         void *target_container, const void *data,
 855                         const struct iphdr *iph)
 856 {
 857         struct flow_dissector_key_ip *key_ip;
 858
 859         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 860                 return;
 861
 862         key_ip = skb_flow_dissector_target(flow_dissector,
 863                                            FLOW_DISSECTOR_KEY_IP,
 864                                            target_container);
 865         key_ip->tos = iph->tos;
 866         key_ip->ttl = iph->ttl;
 867 }
 868
 869 static void
 870 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 871                         struct flow_dissector *flow_dissector,
 872                         void *target_container, const void *data,
 873                         const struct ipv6hdr *iph)
 874 {
 875         struct flow_dissector_key_ip *key_ip;
 876
 877         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 878                 return;
 879
 880         key_ip = skb_flow_dissector_target(flow_dissector,
 881                                            FLOW_DISSECTOR_KEY_IP,
 882                                            target_container);
 883         key_ip->tos = ipv6_get_dsfield(iph);
 884         key_ip->ttl = iph->hop_limit;
 885 }
 886
 887 /* Maximum number of protocol headers that can be parsed in
 888  * __skb_flow_dissect
 889  */
 890 #define MAX_FLOW_DISSECT_HDRS   15
 891
 892 static bool skb_flow_dissect_allowed(int *num_hdrs)
 893 {
 894         ++*num_hdrs;
 895
 896         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 897 }
 898
 899 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
 900                                      struct flow_dissector *flow_dissector,
 901                                      void *target_container)
 902 {
 903         struct flow_dissector_key_ports *key_ports = NULL;
 904         struct flow_dissector_key_control *key_control;
 905         struct flow_dissector_key_basic *key_basic;
 906         struct flow_dissector_key_addrs *key_addrs;
 907         struct flow_dissector_key_tags *key_tags;
 908
 909         key_control = skb_flow_dissector_target(flow_dissector,
 910                                                 FLOW_DISSECTOR_KEY_CONTROL,
 911                                                 target_container);
 912         key_control->thoff = flow_keys->thoff;
 913         if (flow_keys->is_frag)
 914                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 915         if (flow_keys->is_first_frag)
 916                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 917         if (flow_keys->is_encap)
 918                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 919
 920         key_basic = skb_flow_dissector_target(flow_dissector,
 921                                               FLOW_DISSECTOR_KEY_BASIC,
 922                                               target_container);
 923         key_basic->n_proto = flow_keys->n_proto;
 924         key_basic->ip_proto = flow_keys->ip_proto;
 925
 926         if (flow_keys->addr_proto == ETH_P_IP &&
 927             dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 928                 key_addrs = skb_flow_dissector_target(flow_dissector,
 929                                                       FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 930                                                       target_container);
 931                 key_addrs->v4addrs.src = flow_keys->ipv4_src;
 932                 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
 933                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 934         } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
 935                    dissector_uses_key(flow_dissector,
 936                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 937                 key_addrs = skb_flow_dissector_target(flow_dissector,
 938                                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 939                                                       target_container);
 940                 memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src,
 941                        sizeof(key_addrs->v6addrs.src));
 942                 memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst,
 943                        sizeof(key_addrs->v6addrs.dst));
 944                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 945         }
 946
 947         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
 948                 key_ports = skb_flow_dissector_target(flow_dissector,
 949                                                       FLOW_DISSECTOR_KEY_PORTS,
 950                                                       target_container);
 951         else if (dissector_uses_key(flow_dissector,
 952                                     FLOW_DISSECTOR_KEY_PORTS_RANGE))
 953                 key_ports = skb_flow_dissector_target(flow_dissector,
 954                                                       FLOW_DISSECTOR_KEY_PORTS_RANGE,
 955                                                       target_container);
 956
 957         if (key_ports) {
 958                 key_ports->src = flow_keys->sport;
 959                 key_ports->dst = flow_keys->dport;
 960         }
 961
 962         if (dissector_uses_key(flow_dissector,
 963                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 964                 key_tags = skb_flow_dissector_target(flow_dissector,
 965                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 966                                                      target_container);
 967                 key_tags->flow_label = ntohl(flow_keys->flow_label);
 968         }
 969 }
 970
 971 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
 972                      __be16 proto, int nhoff, int hlen, unsigned int flags)
 973 {
 974         struct bpf_flow_keys *flow_keys = ctx->flow_keys;
 975         u32 result;
 976
 977         /* Pass parameters to the BPF program */
 978         memset(flow_keys, 0, sizeof(*flow_keys));
 979         flow_keys->n_proto = proto;
 980         flow_keys->nhoff = nhoff;
 981         flow_keys->thoff = flow_keys->nhoff;
 982
 983         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
 984                      (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
 985         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
 986                      (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 987         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
 988                      (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
 989         flow_keys->flags = flags;
 990
 991         result = bpf_prog_run_pin_on_cpu(prog, ctx);
 992
 993         flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
 994         flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
 995                                    flow_keys->nhoff, hlen);
 996
 997         return result;
 998 }
 999
1000 static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr)
1001 {
1002         return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0;
1003 }
1004
1005 /**
1006  * __skb_flow_dissect - extract the flow_keys struct and return it
1007  * @net: associated network namespace, derived from @skb if NULL
1008  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
1009  * @flow_dissector: list of keys to dissect
1010  * @target_container: target structure to put dissected values into
1011  * @data: raw buffer pointer to the packet, if NULL use skb->data
1012  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
1013  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
1014  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
1015  * @flags: flags that control the dissection process, e.g.
1016  *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
1017  *
1018  * The function will try to retrieve individual keys into target specified
1019  * by flow_dissector from either the skbuff or a raw buffer specified by the
1020  * rest parameters.
1021  *
1022  * Caller must take care of zeroing target container memory.
1023  */
1024 bool __skb_flow_dissect(const struct net *net,
1025                         const struct sk_buff *skb,
1026                         struct flow_dissector *flow_dissector,
1027                         void *target_container, const void *data,
1028                         __be16 proto, int nhoff, int hlen, unsigned int flags)
1029 {
1030         struct flow_dissector_key_control *key_control;
1031         struct flow_dissector_key_basic *key_basic;
1032         struct flow_dissector_key_addrs *key_addrs;
1033         struct flow_dissector_key_tags *key_tags;
1034         struct flow_dissector_key_vlan *key_vlan;
1035         enum flow_dissect_ret fdret;
1036         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
1037         bool mpls_el = false;
1038         int mpls_lse = 0;
1039         int num_hdrs = 0;
1040         u8 ip_proto = 0;
1041         bool ret;
1042
1043         if (!data) {
1044                 data = skb->data;
1045                 proto = skb_vlan_tag_present(skb) ?
1046                          skb->vlan_proto : skb->protocol;
1047                 nhoff = skb_network_offset(skb);
1048                 hlen = skb_headlen(skb);
1049 #if IS_ENABLED(CONFIG_NET_DSA)
1050                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
1051                              proto == htons(ETH_P_XDSA))) {
1052                         struct metadata_dst *md_dst = skb_metadata_dst(skb);
1053                         const struct dsa_device_ops *ops;
1054                         int offset = 0;
1055
1056                         ops = skb->dev->dsa_ptr->tag_ops;
1057                         /* Only DSA header taggers break flow dissection */
1058                         if (ops->needed_headroom &&
1059                             (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
1060                                 if (ops->flow_dissect)
1061                                         ops->flow_dissect(skb, &proto, &offset);
1062                                 else
1063                                         dsa_tag_generic_flow_dissect(skb,
1064                                                                      &proto,
1065                                                                      &offset);
1066                                 hlen -= offset;
1067                                 nhoff += offset;
1068                         }
1069                 }
1070 #endif
1071         }
1072
1073         /* It is ensured by skb_flow_dissector_init() that control key will
1074          * be always present.
1075          */
1076         key_control = skb_flow_dissector_target(flow_dissector,
1077                                                 FLOW_DISSECTOR_KEY_CONTROL,
1078                                                 target_container);
1079
1080         /* It is ensured by skb_flow_dissector_init() that basic key will
1081          * be always present.
1082          */
1083         key_basic = skb_flow_dissector_target(flow_dissector,
1084                                               FLOW_DISSECTOR_KEY_BASIC,
1085                                               target_container);
1086
1087         if (skb) {
1088                 if (!net) {
1089                         if (skb->dev)
1090                                 net = dev_net(skb->dev);
1091                         else if (skb->sk)
1092                                 net = sock_net(skb->sk);
1093                 }
1094         }
1095
1096         WARN_ON_ONCE(!net);
1097         if (net) {
1098                 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
1099                 struct bpf_prog_array *run_array;
1100
1101                 rcu_read_lock();
1102                 run_array = rcu_dereference(init_net.bpf.run_array[type]);
1103                 if (!run_array)
1104                         run_array = rcu_dereference(net->bpf.run_array[type]);
1105
1106                 if (run_array) {
1107                         struct bpf_flow_keys flow_keys;
1108                         struct bpf_flow_dissector ctx = {
1109                                 .flow_keys = &flow_keys,
1110                                 .data = data,
1111                                 .data_end = data + hlen,
1112                         };
1113                         __be16 n_proto = proto;
1114                         struct bpf_prog *prog;
1115                         u32 result;
1116
1117                         if (skb) {
1118                                 ctx.skb = skb;
1119                                 /* we can't use 'proto' in the skb case
1120                                  * because it might be set to skb->vlan_proto
1121                                  * which has been pulled from the data
1122                                  */
1123                                 n_proto = skb->protocol;
1124                         }
1125
1126                         prog = READ_ONCE(run_array->items[0].prog);
1127                         result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,
1128                                                   hlen, flags);
1129                         if (result == BPF_FLOW_DISSECTOR_CONTINUE)
1130                                 goto dissect_continue;
1131                         __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1132                                                  target_container);
1133                         rcu_read_unlock();
1134                         return result == BPF_OK;
1135                 }
1136 dissect_continue:
1137                 rcu_read_unlock();
1138         }
1139
1140         if (dissector_uses_key(flow_dissector,
1141                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1142                 struct ethhdr *eth = eth_hdr(skb);
1143                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
1144
1145                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1146                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
1147                                                           target_container);
1148                 memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs));
1149         }
1150
1151         if (dissector_uses_key(flow_dissector,
1152                                FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) {
1153                 struct flow_dissector_key_num_of_vlans *key_num_of_vlans;
1154
1155                 key_num_of_vlans = skb_flow_dissector_target(flow_dissector,
1156                                                              FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1157                                                              target_container);
1158                 key_num_of_vlans->num_of_vlans = 0;
1159         }
1160
1161 proto_again:
1162         fdret = FLOW_DISSECT_RET_CONTINUE;
1163
1164         switch (proto) {
1165         case htons(ETH_P_IP): {
1166                 const struct iphdr *iph;
1167                 struct iphdr _iph;
1168
1169                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1170                 if (!iph || iph->ihl < 5) {
1171                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1172                         break;
1173                 }
1174
1175                 nhoff += iph->ihl * 4;
1176
1177                 ip_proto = iph->protocol;
1178
1179                 if (dissector_uses_key(flow_dissector,
1180                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1181                         key_addrs = skb_flow_dissector_target(flow_dissector,
1182                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1183                                                               target_container);
1184
1185                         memcpy(&key_addrs->v4addrs.src, &iph->saddr,
1186                                sizeof(key_addrs->v4addrs.src));
1187                         memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
1188                                sizeof(key_addrs->v4addrs.dst));
1189                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1190                 }
1191
1192                 __skb_flow_dissect_ipv4(skb, flow_dissector,
1193                                         target_container, data, iph);
1194
1195                 if (ip_is_fragment(iph)) {
1196                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1197
1198                         if (iph->frag_off & htons(IP_OFFSET)) {
1199                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1200                                 break;
1201                         } else {
1202                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1203                                 if (!(flags &
1204                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1205                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1206                                         break;
1207                                 }
1208                         }
1209                 }
1210
1211                 break;
1212         }
1213         case htons(ETH_P_IPV6): {
1214                 const struct ipv6hdr *iph;
1215                 struct ipv6hdr _iph;
1216
1217                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1218                 if (!iph) {
1219                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1220                         break;
1221                 }
1222
1223                 ip_proto = iph->nexthdr;
1224                 nhoff += sizeof(struct ipv6hdr);
1225
1226                 if (dissector_uses_key(flow_dissector,
1227                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1228                         key_addrs = skb_flow_dissector_target(flow_dissector,
1229                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1230                                                               target_container);
1231
1232                         memcpy(&key_addrs->v6addrs.src, &iph->saddr,
1233                                sizeof(key_addrs->v6addrs.src));
1234                         memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
1235                                sizeof(key_addrs->v6addrs.dst));
1236                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1237                 }
1238
1239                 if ((dissector_uses_key(flow_dissector,
1240                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1241                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1242                     ip6_flowlabel(iph)) {
1243                         __be32 flow_label = ip6_flowlabel(iph);
1244
1245                         if (dissector_uses_key(flow_dissector,
1246                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1247                                 key_tags = skb_flow_dissector_target(flow_dissector,
1248                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
1249                                                                      target_container);
1250                                 key_tags->flow_label = ntohl(flow_label);
1251                         }
1252                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1253                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1254                                 break;
1255                         }
1256                 }
1257
1258                 __skb_flow_dissect_ipv6(skb, flow_dissector,
1259                                         target_container, data, iph);
1260
1261                 break;
1262         }
1263         case htons(ETH_P_8021AD):
1264         case htons(ETH_P_8021Q): {
1265                 const struct vlan_hdr *vlan = NULL;
1266                 struct vlan_hdr _vlan;
1267                 __be16 saved_vlan_tpid = proto;
1268
1269                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1270                     skb && skb_vlan_tag_present(skb)) {
1271                         proto = skb->protocol;
1272                 } else {
1273                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1274                                                     data, hlen, &_vlan);
1275                         if (!vlan) {
1276                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1277                                 break;
1278                         }
1279
1280                         proto = vlan->h_vlan_encapsulated_proto;
1281                         nhoff += sizeof(*vlan);
1282                 }
1283
1284                 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) &&
1285                     !(key_control->flags & FLOW_DIS_ENCAPSULATION)) {
1286                         struct flow_dissector_key_num_of_vlans *key_nvs;
1287
1288                         key_nvs = skb_flow_dissector_target(flow_dissector,
1289                                                             FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1290                                                             target_container);
1291                         key_nvs->num_of_vlans++;
1292                 }
1293
1294                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1295                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1296                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1297                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1298                 } else {
1299                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1300                         break;
1301                 }
1302
1303                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1304                         key_vlan = skb_flow_dissector_target(flow_dissector,
1305                                                              dissector_vlan,
1306                                                              target_container);
1307
1308                         if (!vlan) {
1309                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1310                                 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1311                         } else {
1312                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1313                                         VLAN_VID_MASK;
1314                                 key_vlan->vlan_priority =
1315                                         (ntohs(vlan->h_vlan_TCI) &
1316                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1317                         }
1318                         key_vlan->vlan_tpid = saved_vlan_tpid;
1319                         key_vlan->vlan_eth_type = proto;
1320                 }
1321
1322                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1323                 break;
1324         }
1325         case htons(ETH_P_PPP_SES): {
1326                 struct {
1327                         struct pppoe_hdr hdr;
1328                         __be16 proto;
1329                 } *hdr, _hdr;
1330                 u16 ppp_proto;
1331
1332                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1333                 if (!hdr) {
1334                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1335                         break;
1336                 }
1337
1338                 if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) {
1339                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1340                         break;
1341                 }
1342
1343                 /* least significant bit of the most significant octet
1344                  * indicates if protocol field was compressed
1345                  */
1346                 ppp_proto = ntohs(hdr->proto);
1347                 if (ppp_proto & 0x0100) {
1348                         ppp_proto = ppp_proto >> 8;
1349                         nhoff += PPPOE_SES_HLEN - 1;
1350                 } else {
1351                         nhoff += PPPOE_SES_HLEN;
1352                 }
1353
1354                 if (ppp_proto == PPP_IP) {
1355                         proto = htons(ETH_P_IP);
1356                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1357                 } else if (ppp_proto == PPP_IPV6) {
1358                         proto = htons(ETH_P_IPV6);
1359                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1360                 } else if (ppp_proto == PPP_MPLS_UC) {
1361                         proto = htons(ETH_P_MPLS_UC);
1362                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1363                 } else if (ppp_proto == PPP_MPLS_MC) {
1364                         proto = htons(ETH_P_MPLS_MC);
1365                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1366                 } else if (ppp_proto_is_valid(ppp_proto)) {
1367                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1368                 } else {
1369                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1370                         break;
1371                 }
1372
1373                 if (dissector_uses_key(flow_dissector,
1374                                        FLOW_DISSECTOR_KEY_PPPOE)) {
1375                         struct flow_dissector_key_pppoe *key_pppoe;
1376
1377                         key_pppoe = skb_flow_dissector_target(flow_dissector,
1378                                                               FLOW_DISSECTOR_KEY_PPPOE,
1379                                                               target_container);
1380                         key_pppoe->session_id = hdr->hdr.sid;
1381                         key_pppoe->ppp_proto = htons(ppp_proto);
1382                         key_pppoe->type = htons(ETH_P_PPP_SES);
1383                 }
1384                 break;
1385         }
1386         case htons(ETH_P_TIPC): {
1387                 struct tipc_basic_hdr *hdr, _hdr;
1388
1389                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1390                                            data, hlen, &_hdr);
1391                 if (!hdr) {
1392                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1393                         break;
1394                 }
1395
1396                 if (dissector_uses_key(flow_dissector,
1397                                        FLOW_DISSECTOR_KEY_TIPC)) {
1398                         key_addrs = skb_flow_dissector_target(flow_dissector,
1399                                                               FLOW_DISSECTOR_KEY_TIPC,
1400                                                               target_container);
1401                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1402                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1403                 }
1404                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1405                 break;
1406         }
1407
1408         case htons(ETH_P_MPLS_UC):
1409         case htons(ETH_P_MPLS_MC):
1410                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1411                                                 target_container, data,
1412                                                 nhoff, hlen, mpls_lse,
1413                                                 &mpls_el);
1414                 nhoff += sizeof(struct mpls_label);
1415                 mpls_lse++;
1416                 break;
1417         case htons(ETH_P_FCOE):
1418                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1419                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1420                         break;
1421                 }
1422
1423                 nhoff += FCOE_HEADER_LEN;
1424                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1425                 break;
1426
1427         case htons(ETH_P_ARP):
1428         case htons(ETH_P_RARP):
1429                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1430                                                target_container, data,
1431                                                nhoff, hlen);
1432                 break;
1433
1434         case htons(ETH_P_BATMAN):
1435                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1436                                                   &proto, &nhoff, hlen, flags);
1437                 break;
1438
1439         case htons(ETH_P_1588): {
1440                 struct ptp_header *hdr, _hdr;
1441
1442                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
1443                                            hlen, &_hdr);
1444                 if (!hdr) {
1445                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1446                         break;
1447                 }
1448
1449                 nhoff += ntohs(hdr->message_length);
1450                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1451                 break;
1452         }
1453
1454         case htons(ETH_P_PRP):
1455         case htons(ETH_P_HSR): {
1456                 struct hsr_tag *hdr, _hdr;
1457
1458                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen,
1459                                            &_hdr);
1460                 if (!hdr) {
1461                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1462                         break;
1463                 }
1464
1465                 proto = hdr->encap_proto;
1466                 nhoff += HSR_HLEN;
1467                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1468                 break;
1469         }
1470
1471         case htons(ETH_P_CFM):
1472                 fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
1473                                                target_container, data,
1474                                                nhoff, hlen);
1475                 break;
1476
1477         default:
1478                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1479                 break;
1480         }
1481
1482         /* Process result of proto processing */
1483         switch (fdret) {
1484         case FLOW_DISSECT_RET_OUT_GOOD:
1485                 goto out_good;
1486         case FLOW_DISSECT_RET_PROTO_AGAIN:
1487                 if (skb_flow_dissect_allowed(&num_hdrs))
1488                         goto proto_again;
1489                 goto out_good;
1490         case FLOW_DISSECT_RET_CONTINUE:
1491         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1492                 break;
1493         case FLOW_DISSECT_RET_OUT_BAD:
1494         default:
1495                 goto out_bad;
1496         }
1497
1498 ip_proto_again:
1499         fdret = FLOW_DISSECT_RET_CONTINUE;
1500
1501         switch (ip_proto) {
1502         case IPPROTO_GRE:
1503                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1504                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1505                         break;
1506                 }
1507
1508                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1509                                                target_container, data,
1510                                                &proto, &nhoff, &hlen, flags);
1511                 break;
1512
1513         case NEXTHDR_HOP:
1514         case NEXTHDR_ROUTING:
1515         case NEXTHDR_DEST: {
1516                 u8 _opthdr[2], *opthdr;
1517
1518                 if (proto != htons(ETH_P_IPV6))
1519                         break;
1520
1521                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1522                                               data, hlen, &_opthdr);
1523                 if (!opthdr) {
1524                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1525                         break;
1526                 }
1527
1528                 ip_proto = opthdr[0];
1529                 nhoff += (opthdr[1] + 1) << 3;
1530
1531                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1532                 break;
1533         }
1534         case NEXTHDR_FRAGMENT: {
1535                 struct frag_hdr _fh, *fh;
1536
1537                 if (proto != htons(ETH_P_IPV6))
1538                         break;
1539
1540                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1541                                           data, hlen, &_fh);
1542
1543                 if (!fh) {
1544                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1545                         break;
1546                 }
1547
1548                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1549
1550                 nhoff += sizeof(_fh);
1551                 ip_proto = fh->nexthdr;
1552
1553                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1554                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
1555                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1556                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1557                                 break;
1558                         }
1559                 }
1560
1561                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1562                 break;
1563         }
1564         case IPPROTO_IPIP:
1565                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1566                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1567                         break;
1568                 }
1569
1570                 proto = htons(ETH_P_IP);
1571
1572                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1573                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1574                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1575                         break;
1576                 }
1577
1578                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1579                 break;
1580
1581         case IPPROTO_IPV6:
1582                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1583                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1584                         break;
1585                 }
1586
1587                 proto = htons(ETH_P_IPV6);
1588
1589                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1590                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1591                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1592                         break;
1593                 }
1594
1595                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1596                 break;
1597
1598
1599         case IPPROTO_MPLS:
1600                 proto = htons(ETH_P_MPLS_UC);
1601                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1602                 break;
1603
1604         case IPPROTO_TCP:
1605                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1606                                        data, nhoff, hlen);
1607                 break;
1608
1609         case IPPROTO_ICMP:
1610         case IPPROTO_ICMPV6:
1611                 __skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1612                                         data, nhoff, hlen);
1613                 break;
1614         case IPPROTO_L2TP:
1615                 __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container,
1616                                           data, nhoff, hlen);
1617                 break;
1618         case IPPROTO_ESP:
1619                 __skb_flow_dissect_esp(skb, flow_dissector, target_container,
1620                                        data, nhoff, hlen);
1621                 break;
1622         case IPPROTO_AH:
1623                 __skb_flow_dissect_ah(skb, flow_dissector, target_container,
1624                                       data, nhoff, hlen);
1625                 break;
1626         default:
1627                 break;
1628         }
1629
1630         if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT))
1631                 __skb_flow_dissect_ports(skb, flow_dissector, target_container,
1632                                          data, nhoff, ip_proto, hlen);
1633
1634         /* Process result of IP proto processing */
1635         switch (fdret) {
1636         case FLOW_DISSECT_RET_PROTO_AGAIN:
1637                 if (skb_flow_dissect_allowed(&num_hdrs))
1638                         goto proto_again;
1639                 break;
1640         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1641                 if (skb_flow_dissect_allowed(&num_hdrs))
1642                         goto ip_proto_again;
1643                 break;
1644         case FLOW_DISSECT_RET_OUT_GOOD:
1645         case FLOW_DISSECT_RET_CONTINUE:
1646                 break;
1647         case FLOW_DISSECT_RET_OUT_BAD:
1648         default:
1649                 goto out_bad;
1650         }
1651
1652 out_good:
1653         ret = true;
1654
1655 out:
1656         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1657         key_basic->n_proto = proto;
1658         key_basic->ip_proto = ip_proto;
1659
1660         return ret;
1661
1662 out_bad:
1663         ret = false;
1664         goto out;
1665 }
1666 EXPORT_SYMBOL(__skb_flow_dissect);
1667
1668 static siphash_aligned_key_t hashrnd;
1669 static __always_inline void __flow_hash_secret_init(void)
1670 {
1671         net_get_random_once(&hashrnd, sizeof(hashrnd));
1672 }
1673
1674 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1675 {
1676         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1677         return &flow->FLOW_KEYS_HASH_START_FIELD;
1678 }
1679
1680 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1681 {
1682         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1683
1684         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1685
1686         switch (flow->control.addr_type) {
1687         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1688                 diff -= sizeof(flow->addrs.v4addrs);
1689                 break;
1690         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1691                 diff -= sizeof(flow->addrs.v6addrs);
1692                 break;
1693         case FLOW_DISSECTOR_KEY_TIPC:
1694                 diff -= sizeof(flow->addrs.tipckey);
1695                 break;
1696         }
1697         return sizeof(*flow) - diff;
1698 }
1699
1700 __be32 flow_get_u32_src(const struct flow_keys *flow)
1701 {
1702         switch (flow->control.addr_type) {
1703         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1704                 return flow->addrs.v4addrs.src;
1705         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1706                 return (__force __be32)ipv6_addr_hash(
1707                         &flow->addrs.v6addrs.src);
1708         case FLOW_DISSECTOR_KEY_TIPC:
1709                 return flow->addrs.tipckey.key;
1710         default:
1711                 return 0;
1712         }
1713 }
1714 EXPORT_SYMBOL(flow_get_u32_src);
1715
1716 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1717 {
1718         switch (flow->control.addr_type) {
1719         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1720                 return flow->addrs.v4addrs.dst;
1721         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1722                 return (__force __be32)ipv6_addr_hash(
1723                         &flow->addrs.v6addrs.dst);
1724         default:
1725                 return 0;
1726         }
1727 }
1728 EXPORT_SYMBOL(flow_get_u32_dst);
1729
1730 /* Sort the source and destination IP and the ports,
1731  * to have consistent hash within the two directions
1732  */
1733 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1734 {
1735         int addr_diff, i;
1736
1737         switch (keys->control.addr_type) {
1738         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1739                 if ((__force u32)keys->addrs.v4addrs.dst <
1740                     (__force u32)keys->addrs.v4addrs.src)
1741                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1742
1743                 if ((__force u16)keys->ports.dst <
1744                     (__force u16)keys->ports.src) {
1745                         swap(keys->ports.src, keys->ports.dst);
1746                 }
1747                 break;
1748         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1749                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1750                                    &keys->addrs.v6addrs.src,
1751                                    sizeof(keys->addrs.v6addrs.dst));
1752                 if (addr_diff < 0) {
1753                         for (i = 0; i < 4; i++)
1754                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1755                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1756                 }
1757                 if ((__force u16)keys->ports.dst <
1758                     (__force u16)keys->ports.src) {
1759                         swap(keys->ports.src, keys->ports.dst);
1760                 }
1761                 break;
1762         }
1763 }
1764
1765 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1766                                         const siphash_key_t *keyval)
1767 {
1768         u32 hash;
1769
1770         __flow_hash_consistentify(keys);
1771
1772         hash = siphash(flow_keys_hash_start(keys),
1773                        flow_keys_hash_length(keys), keyval);
1774         if (!hash)
1775                 hash = 1;
1776
1777         return hash;
1778 }
1779
1780 u32 flow_hash_from_keys(struct flow_keys *keys)
1781 {
1782         __flow_hash_secret_init();
1783         return __flow_hash_from_keys(keys, &hashrnd);
1784 }
1785 EXPORT_SYMBOL(flow_hash_from_keys);
1786
1787 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1788                                   struct flow_keys *keys,
1789                                   const siphash_key_t *keyval)
1790 {
1791         skb_flow_dissect_flow_keys(skb, keys,
1792                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1793
1794         return __flow_hash_from_keys(keys, keyval);
1795 }
1796
1797 struct _flow_keys_digest_data {
1798         __be16  n_proto;
1799         u8      ip_proto;
1800         u8      padding;
1801         __be32  ports;
1802         __be32  src;
1803         __be32  dst;
1804 };
1805
1806 void make_flow_keys_digest(struct flow_keys_digest *digest,
1807                            const struct flow_keys *flow)
1808 {
1809         struct _flow_keys_digest_data *data =
1810             (struct _flow_keys_digest_data *)digest;
1811
1812         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1813
1814         memset(digest, 0, sizeof(*digest));
1815
1816         data->n_proto = flow->basic.n_proto;
1817         data->ip_proto = flow->basic.ip_proto;
1818         data->ports = flow->ports.ports;
1819         data->src = flow->addrs.v4addrs.src;
1820         data->dst = flow->addrs.v4addrs.dst;
1821 }
1822 EXPORT_SYMBOL(make_flow_keys_digest);
1823
1824 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1825
1826 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1827 {
1828         struct flow_keys keys;
1829
1830         __flow_hash_secret_init();
1831
1832         memset(&keys, 0, sizeof(keys));
1833         __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1834                            &keys, NULL, 0, 0, 0, 0);
1835
1836         return __flow_hash_from_keys(&keys, &hashrnd);
1837 }
1838 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1839
1840 /**
1841  * __skb_get_hash: calculate a flow hash
1842  * @skb: sk_buff to calculate flow hash from
1843  *
1844  * This function calculates a flow hash based on src/dst addresses
1845  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1846  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1847  * if hash is a canonical 4-tuple hash over transport ports.
1848  */
1849 void __skb_get_hash(struct sk_buff *skb)
1850 {
1851         struct flow_keys keys;
1852         u32 hash;
1853
1854         __flow_hash_secret_init();
1855
1856         hash = ___skb_get_hash(skb, &keys, &hashrnd);
1857
1858         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1859 }
1860 EXPORT_SYMBOL(__skb_get_hash);
1861
1862 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1863                            const siphash_key_t *perturb)
1864 {
1865         struct flow_keys keys;
1866
1867         return ___skb_get_hash(skb, &keys, perturb);
1868 }
1869 EXPORT_SYMBOL(skb_get_hash_perturb);
1870
1871 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1872                    const struct flow_keys_basic *keys, int hlen)
1873 {
1874         u32 poff = keys->control.thoff;
1875
1876         /* skip L4 headers for fragments after the first */
1877         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1878             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1879                 return poff;
1880
1881         switch (keys->basic.ip_proto) {
1882         case IPPROTO_TCP: {
1883                 /* access doff as u8 to avoid unaligned access */
1884                 const u8 *doff;
1885                 u8 _doff;
1886
1887                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1888                                             data, hlen, &_doff);
1889                 if (!doff)
1890                         return poff;
1891
1892                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1893                 break;
1894         }
1895         case IPPROTO_UDP:
1896         case IPPROTO_UDPLITE:
1897                 poff += sizeof(struct udphdr);
1898                 break;
1899         /* For the rest, we do not really care about header
1900          * extensions at this point for now.
1901          */
1902         case IPPROTO_ICMP:
1903                 poff += sizeof(struct icmphdr);
1904                 break;
1905         case IPPROTO_ICMPV6:
1906                 poff += sizeof(struct icmp6hdr);
1907                 break;
1908         case IPPROTO_IGMP:
1909                 poff += sizeof(struct igmphdr);
1910                 break;
1911         case IPPROTO_DCCP:
1912                 poff += sizeof(struct dccp_hdr);
1913                 break;
1914         case IPPROTO_SCTP:
1915                 poff += sizeof(struct sctphdr);
1916                 break;
1917         }
1918
1919         return poff;
1920 }
1921
1922 /**
1923  * skb_get_poff - get the offset to the payload
1924  * @skb: sk_buff to get the payload offset from
1925  *
1926  * The function will get the offset to the payload as far as it could
1927  * be dissected.  The main user is currently BPF, so that we can dynamically
1928  * truncate packets without needing to push actual payload to the user
1929  * space and can analyze headers only, instead.
1930  */
1931 u32 skb_get_poff(const struct sk_buff *skb)
1932 {
1933         struct flow_keys_basic keys;
1934
1935         if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1936                                               NULL, 0, 0, 0, 0))
1937                 return 0;
1938
1939         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1940 }
1941
1942 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1943 {
1944         memset(keys, 0, sizeof(*keys));
1945
1946         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1947             sizeof(keys->addrs.v6addrs.src));
1948         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1949             sizeof(keys->addrs.v6addrs.dst));
1950         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1951         keys->ports.src = fl6->fl6_sport;
1952         keys->ports.dst = fl6->fl6_dport;
1953         keys->keyid.keyid = fl6->fl6_gre_key;
1954         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1955         keys->basic.ip_proto = fl6->flowi6_proto;
1956
1957         return flow_hash_from_keys(keys);
1958 }
1959 EXPORT_SYMBOL(__get_hash_from_flowi6);
1960
1961 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1962         {
1963                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1964                 .offset = offsetof(struct flow_keys, control),
1965         },
1966         {
1967                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1968                 .offset = offsetof(struct flow_keys, basic),
1969         },
1970         {
1971                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1972                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1973         },
1974         {
1975                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1976                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1977         },
1978         {
1979                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1980                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1981         },
1982         {
1983                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1984                 .offset = offsetof(struct flow_keys, ports),
1985         },
1986         {
1987                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1988                 .offset = offsetof(struct flow_keys, vlan),
1989         },
1990         {
1991                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1992                 .offset = offsetof(struct flow_keys, tags),
1993         },
1994         {
1995                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1996                 .offset = offsetof(struct flow_keys, keyid),
1997         },
1998 };
1999
2000 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
2001         {
2002                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
2003                 .offset = offsetof(struct flow_keys, control),
2004         },
2005         {
2006                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
2007                 .offset = offsetof(struct flow_keys, basic),
2008         },
2009         {
2010                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
2011                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
2012         },
2013         {
2014                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
2015                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
2016         },
2017         {
2018                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
2019                 .offset = offsetof(struct flow_keys, ports),
2020         },
2021 };
2022
2023 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
2024         {
2025                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
2026                 .offset = offsetof(struct flow_keys, control),
2027         },
2028         {
2029                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
2030                 .offset = offsetof(struct flow_keys, basic),
2031         },
2032 };
2033
2034 struct flow_dissector flow_keys_dissector __read_mostly;
2035 EXPORT_SYMBOL(flow_keys_dissector);
2036
2037 struct flow_dissector flow_keys_basic_dissector __read_mostly;
2038 EXPORT_SYMBOL(flow_keys_basic_dissector);
2039
2040 static int __init init_default_flow_dissectors(void)
2041 {
2042         skb_flow_dissector_init(&flow_keys_dissector,
2043                                 flow_keys_dissector_keys,
2044                                 ARRAY_SIZE(flow_keys_dissector_keys));
2045         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
2046                                 flow_keys_dissector_symmetric_keys,
2047                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
2048         skb_flow_dissector_init(&flow_keys_basic_dissector,
2049                                 flow_keys_basic_dissector_keys,
2050                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
2051         return 0;
2052 }
2053 core_initcall(init_default_flow_dissectors);