net/core/flow_dissector.c

   1 #include <linux/kernel.h>
   2 #include <linux/skbuff.h>
   3 #include <linux/export.h>
   4 #include <linux/ip.h>
   5 #include <linux/ipv6.h>
   6 #include <linux/if_vlan.h>
   7 #include <net/dsa.h>
   8 #include <net/dst_metadata.h>
   9 #include <net/ip.h>
  10 #include <net/ipv6.h>
  11 #include <net/gre.h>
  12 #include <net/pptp.h>
  13 #include <net/tipc.h>
  14 #include <linux/igmp.h>
  15 #include <linux/icmp.h>
  16 #include <linux/sctp.h>
  17 #include <linux/dccp.h>
  18 #include <linux/if_tunnel.h>
  19 #include <linux/if_pppox.h>
  20 #include <linux/ppp_defs.h>
  21 #include <linux/stddef.h>
  22 #include <linux/if_ether.h>
  23 #include <linux/mpls.h>
  24 #include <linux/tcp.h>
  25 #include <net/flow_dissector.h>
  26 #include <scsi/fc/fc_fcoe.h>
  27 #include <uapi/linux/batadv_packet.h>
  28
  29 static void dissector_set_key(struct flow_dissector *flow_dissector,
  30                               enum flow_dissector_key_id key_id)
  31 {
  32         flow_dissector->used_keys |= (1 << key_id);
  33 }
  34
  35 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  36                              const struct flow_dissector_key *key,
  37                              unsigned int key_count)
  38 {
  39         unsigned int i;
  40
  41         memset(flow_dissector, 0, sizeof(*flow_dissector));
  42
  43         for (i = 0; i < key_count; i++, key++) {
  44                 /* User should make sure that every key target offset is withing
  45                  * boundaries of unsigned short.
  46                  */
  47                 BUG_ON(key->offset > USHRT_MAX);
  48                 BUG_ON(dissector_uses_key(flow_dissector,
  49                                           key->key_id));
  50
  51                 dissector_set_key(flow_dissector, key->key_id);
  52                 flow_dissector->offset[key->key_id] = key->offset;
  53         }
  54
  55         /* Ensure that the dissector always includes control and basic key.
  56          * That way we are able to avoid handling lack of these in fast path.
  57          */
  58         BUG_ON(!dissector_uses_key(flow_dissector,
  59                                    FLOW_DISSECTOR_KEY_CONTROL));
  60         BUG_ON(!dissector_uses_key(flow_dissector,
  61                                    FLOW_DISSECTOR_KEY_BASIC));
  62 }
  63 EXPORT_SYMBOL(skb_flow_dissector_init);
  64
  65 /**
  66  * skb_flow_get_be16 - extract be16 entity
  67  * @skb: sk_buff to extract from
  68  * @poff: offset to extract at
  69  * @data: raw buffer pointer to the packet
  70  * @hlen: packet header length
  71  *
  72  * The function will try to retrieve a be32 entity at
  73  * offset poff
  74  */
  75 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
  76                                 void *data, int hlen)
  77 {
  78         __be16 *u, _u;
  79
  80         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
  81         if (u)
  82                 return *u;
  83
  84         return 0;
  85 }
  86
  87 /**
  88  * __skb_flow_get_ports - extract the upper layer ports and return them
  89  * @skb: sk_buff to extract the ports from
  90  * @thoff: transport header offset
  91  * @ip_proto: protocol for which to get port offset
  92  * @data: raw buffer pointer to the packet, if NULL use skb->data
  93  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  94  *
  95  * The function will try to retrieve the ports at offset thoff + poff where poff
  96  * is the protocol port offset returned from proto_ports_offset
  97  */
  98 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  99                             void *data, int hlen)
 100 {
 101         int poff = proto_ports_offset(ip_proto);
 102
 103         if (!data) {
 104                 data = skb->data;
 105                 hlen = skb_headlen(skb);
 106         }
 107
 108         if (poff >= 0) {
 109                 __be32 *ports, _ports;
 110
 111                 ports = __skb_header_pointer(skb, thoff + poff,
 112                                              sizeof(_ports), data, hlen, &_ports);
 113                 if (ports)
 114                         return *ports;
 115         }
 116
 117         return 0;
 118 }
 119 EXPORT_SYMBOL(__skb_flow_get_ports);
 120
 121 static void
 122 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
 123                                    struct flow_dissector *flow_dissector,
 124                                    void *target_container)
 125 {
 126         struct flow_dissector_key_control *ctrl;
 127
 128         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
 129                 return;
 130
 131         ctrl = skb_flow_dissector_target(flow_dissector,
 132                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
 133                                          target_container);
 134         ctrl->addr_type = type;
 135 }
 136
 137 void
 138 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
 139                              struct flow_dissector *flow_dissector,
 140                              void *target_container)
 141 {
 142         struct ip_tunnel_info *info;
 143         struct ip_tunnel_key *key;
 144
 145         /* A quick check to see if there might be something to do. */
 146         if (!dissector_uses_key(flow_dissector,
 147                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
 148             !dissector_uses_key(flow_dissector,
 149                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
 150             !dissector_uses_key(flow_dissector,
 151                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
 152             !dissector_uses_key(flow_dissector,
 153                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
 154             !dissector_uses_key(flow_dissector,
 155                                 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
 156             !dissector_uses_key(flow_dissector,
 157                                 FLOW_DISSECTOR_KEY_ENC_IP) &&
 158             !dissector_uses_key(flow_dissector,
 159                                 FLOW_DISSECTOR_KEY_ENC_OPTS))
 160                 return;
 161
 162         info = skb_tunnel_info(skb);
 163         if (!info)
 164                 return;
 165
 166         key = &info->key;
 167
 168         switch (ip_tunnel_info_af(info)) {
 169         case AF_INET:
 170                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 171                                                    flow_dissector,
 172                                                    target_container);
 173                 if (dissector_uses_key(flow_dissector,
 174                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 175                         struct flow_dissector_key_ipv4_addrs *ipv4;
 176
 177                         ipv4 = skb_flow_dissector_target(flow_dissector,
 178                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 179                                                          target_container);
 180                         ipv4->src = key->u.ipv4.src;
 181                         ipv4->dst = key->u.ipv4.dst;
 182                 }
 183                 break;
 184         case AF_INET6:
 185                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 186                                                    flow_dissector,
 187                                                    target_container);
 188                 if (dissector_uses_key(flow_dissector,
 189                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 190                         struct flow_dissector_key_ipv6_addrs *ipv6;
 191
 192                         ipv6 = skb_flow_dissector_target(flow_dissector,
 193                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 194                                                          target_container);
 195                         ipv6->src = key->u.ipv6.src;
 196                         ipv6->dst = key->u.ipv6.dst;
 197                 }
 198                 break;
 199         }
 200
 201         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 202                 struct flow_dissector_key_keyid *keyid;
 203
 204                 keyid = skb_flow_dissector_target(flow_dissector,
 205                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
 206                                                   target_container);
 207                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
 208         }
 209
 210         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 211                 struct flow_dissector_key_ports *tp;
 212
 213                 tp = skb_flow_dissector_target(flow_dissector,
 214                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
 215                                                target_container);
 216                 tp->src = key->tp_src;
 217                 tp->dst = key->tp_dst;
 218         }
 219
 220         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
 221                 struct flow_dissector_key_ip *ip;
 222
 223                 ip = skb_flow_dissector_target(flow_dissector,
 224                                                FLOW_DISSECTOR_KEY_ENC_IP,
 225                                                target_container);
 226                 ip->tos = key->tos;
 227                 ip->ttl = key->ttl;
 228         }
 229
 230         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
 231                 struct flow_dissector_key_enc_opts *enc_opt;
 232
 233                 enc_opt = skb_flow_dissector_target(flow_dissector,
 234                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
 235                                                     target_container);
 236
 237                 if (info->options_len) {
 238                         enc_opt->len = info->options_len;
 239                         ip_tunnel_info_opts_get(enc_opt->data, info);
 240                         enc_opt->dst_opt_type = info->key.tun_flags &
 241                                                 TUNNEL_OPTIONS_PRESENT;
 242                 }
 243         }
 244 }
 245 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 246
 247 static enum flow_dissect_ret
 248 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 249                         struct flow_dissector *flow_dissector,
 250                         void *target_container, void *data, int nhoff, int hlen)
 251 {
 252         struct flow_dissector_key_keyid *key_keyid;
 253         struct mpls_label *hdr, _hdr[2];
 254         u32 entry, label;
 255
 256         if (!dissector_uses_key(flow_dissector,
 257                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 258             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 259                 return FLOW_DISSECT_RET_OUT_GOOD;
 260
 261         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 262                                    hlen, &_hdr);
 263         if (!hdr)
 264                 return FLOW_DISSECT_RET_OUT_BAD;
 265
 266         entry = ntohl(hdr[0].entry);
 267         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 268
 269         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 270                 struct flow_dissector_key_mpls *key_mpls;
 271
 272                 key_mpls = skb_flow_dissector_target(flow_dissector,
 273                                                      FLOW_DISSECTOR_KEY_MPLS,
 274                                                      target_container);
 275                 key_mpls->mpls_label = label;
 276                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
 277                                         >> MPLS_LS_TTL_SHIFT;
 278                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
 279                                         >> MPLS_LS_TC_SHIFT;
 280                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
 281                                         >> MPLS_LS_S_SHIFT;
 282         }
 283
 284         if (label == MPLS_LABEL_ENTROPY) {
 285                 key_keyid = skb_flow_dissector_target(flow_dissector,
 286                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 287                                                       target_container);
 288                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
 289         }
 290         return FLOW_DISSECT_RET_OUT_GOOD;
 291 }
 292
 293 static enum flow_dissect_ret
 294 __skb_flow_dissect_arp(const struct sk_buff *skb,
 295                        struct flow_dissector *flow_dissector,
 296                        void *target_container, void *data, int nhoff, int hlen)
 297 {
 298         struct flow_dissector_key_arp *key_arp;
 299         struct {
 300                 unsigned char ar_sha[ETH_ALEN];
 301                 unsigned char ar_sip[4];
 302                 unsigned char ar_tha[ETH_ALEN];
 303                 unsigned char ar_tip[4];
 304         } *arp_eth, _arp_eth;
 305         const struct arphdr *arp;
 306         struct arphdr _arp;
 307
 308         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 309                 return FLOW_DISSECT_RET_OUT_GOOD;
 310
 311         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 312                                    hlen, &_arp);
 313         if (!arp)
 314                 return FLOW_DISSECT_RET_OUT_BAD;
 315
 316         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 317             arp->ar_pro != htons(ETH_P_IP) ||
 318             arp->ar_hln != ETH_ALEN ||
 319             arp->ar_pln != 4 ||
 320             (arp->ar_op != htons(ARPOP_REPLY) &&
 321              arp->ar_op != htons(ARPOP_REQUEST)))
 322                 return FLOW_DISSECT_RET_OUT_BAD;
 323
 324         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 325                                        sizeof(_arp_eth), data,
 326                                        hlen, &_arp_eth);
 327         if (!arp_eth)
 328                 return FLOW_DISSECT_RET_OUT_BAD;
 329
 330         key_arp = skb_flow_dissector_target(flow_dissector,
 331                                             FLOW_DISSECTOR_KEY_ARP,
 332                                             target_container);
 333
 334         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 335         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 336
 337         /* Only store the lower byte of the opcode;
 338          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 339          */
 340         key_arp->op = ntohs(arp->ar_op) & 0xff;
 341
 342         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 343         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 344
 345         return FLOW_DISSECT_RET_OUT_GOOD;
 346 }
 347
 348 static enum flow_dissect_ret
 349 __skb_flow_dissect_gre(const struct sk_buff *skb,
 350                        struct flow_dissector_key_control *key_control,
 351                        struct flow_dissector *flow_dissector,
 352                        void *target_container, void *data,
 353                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 354                        unsigned int flags)
 355 {
 356         struct flow_dissector_key_keyid *key_keyid;
 357         struct gre_base_hdr *hdr, _hdr;
 358         int offset = 0;
 359         u16 gre_ver;
 360
 361         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 362                                    data, *p_hlen, &_hdr);
 363         if (!hdr)
 364                 return FLOW_DISSECT_RET_OUT_BAD;
 365
 366         /* Only look inside GRE without routing */
 367         if (hdr->flags & GRE_ROUTING)
 368                 return FLOW_DISSECT_RET_OUT_GOOD;
 369
 370         /* Only look inside GRE for version 0 and 1 */
 371         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 372         if (gre_ver > 1)
 373                 return FLOW_DISSECT_RET_OUT_GOOD;
 374
 375         *p_proto = hdr->protocol;
 376         if (gre_ver) {
 377                 /* Version1 must be PPTP, and check the flags */
 378                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 379                         return FLOW_DISSECT_RET_OUT_GOOD;
 380         }
 381
 382         offset += sizeof(struct gre_base_hdr);
 383
 384         if (hdr->flags & GRE_CSUM)
 385                 offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
 386                           sizeof(((struct gre_full_hdr *) 0)->reserved1);
 387
 388         if (hdr->flags & GRE_KEY) {
 389                 const __be32 *keyid;
 390                 __be32 _keyid;
 391
 392                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 393                                              sizeof(_keyid),
 394                                              data, *p_hlen, &_keyid);
 395                 if (!keyid)
 396                         return FLOW_DISSECT_RET_OUT_BAD;
 397
 398                 if (dissector_uses_key(flow_dissector,
 399                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 400                         key_keyid = skb_flow_dissector_target(flow_dissector,
 401                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 402                                                               target_container);
 403                         if (gre_ver == 0)
 404                                 key_keyid->keyid = *keyid;
 405                         else
 406                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 407                 }
 408                 offset += sizeof(((struct gre_full_hdr *) 0)->key);
 409         }
 410
 411         if (hdr->flags & GRE_SEQ)
 412                 offset += sizeof(((struct pptp_gre_header *) 0)->seq);
 413
 414         if (gre_ver == 0) {
 415                 if (*p_proto == htons(ETH_P_TEB)) {
 416                         const struct ethhdr *eth;
 417                         struct ethhdr _eth;
 418
 419                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 420                                                    sizeof(_eth),
 421                                                    data, *p_hlen, &_eth);
 422                         if (!eth)
 423                                 return FLOW_DISSECT_RET_OUT_BAD;
 424                         *p_proto = eth->h_proto;
 425                         offset += sizeof(*eth);
 426
 427                         /* Cap headers that we access via pointers at the
 428                          * end of the Ethernet header as our maximum alignment
 429                          * at that point is only 2 bytes.
 430                          */
 431                         if (NET_IP_ALIGN)
 432                                 *p_hlen = *p_nhoff + offset;
 433                 }
 434         } else { /* version 1, must be PPTP */
 435                 u8 _ppp_hdr[PPP_HDRLEN];
 436                 u8 *ppp_hdr;
 437
 438                 if (hdr->flags & GRE_ACK)
 439                         offset += sizeof(((struct pptp_gre_header *) 0)->ack);
 440
 441                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 442                                                sizeof(_ppp_hdr),
 443                                                data, *p_hlen, _ppp_hdr);
 444                 if (!ppp_hdr)
 445                         return FLOW_DISSECT_RET_OUT_BAD;
 446
 447                 switch (PPP_PROTOCOL(ppp_hdr)) {
 448                 case PPP_IP:
 449                         *p_proto = htons(ETH_P_IP);
 450                         break;
 451                 case PPP_IPV6:
 452                         *p_proto = htons(ETH_P_IPV6);
 453                         break;
 454                 default:
 455                         /* Could probably catch some more like MPLS */
 456                         break;
 457                 }
 458
 459                 offset += PPP_HDRLEN;
 460         }
 461
 462         *p_nhoff += offset;
 463         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 464         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 465                 return FLOW_DISSECT_RET_OUT_GOOD;
 466
 467         return FLOW_DISSECT_RET_PROTO_AGAIN;
 468 }
 469
 470 /**
 471  * __skb_flow_dissect_batadv() - dissect batman-adv header
 472  * @skb: sk_buff to with the batman-adv header
 473  * @key_control: flow dissectors control key
 474  * @data: raw buffer pointer to the packet, if NULL use skb->data
 475  * @p_proto: pointer used to update the protocol to process next
 476  * @p_nhoff: pointer used to update inner network header offset
 477  * @hlen: packet header length
 478  * @flags: any combination of FLOW_DISSECTOR_F_*
 479  *
 480  * ETH_P_BATMAN packets are tried to be dissected. Only
 481  * &struct batadv_unicast packets are actually processed because they contain an
 482  * inner ethernet header and are usually followed by actual network header. This
 483  * allows the flow dissector to continue processing the packet.
 484  *
 485  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 486  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 487  *  otherwise FLOW_DISSECT_RET_OUT_BAD
 488  */
 489 static enum flow_dissect_ret
 490 __skb_flow_dissect_batadv(const struct sk_buff *skb,
 491                           struct flow_dissector_key_control *key_control,
 492                           void *data, __be16 *p_proto, int *p_nhoff, int hlen,
 493                           unsigned int flags)
 494 {
 495         struct {
 496                 struct batadv_unicast_packet batadv_unicast;
 497                 struct ethhdr eth;
 498         } *hdr, _hdr;
 499
 500         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 501                                    &_hdr);
 502         if (!hdr)
 503                 return FLOW_DISSECT_RET_OUT_BAD;
 504
 505         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 506                 return FLOW_DISSECT_RET_OUT_BAD;
 507
 508         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 509                 return FLOW_DISSECT_RET_OUT_BAD;
 510
 511         *p_proto = hdr->eth.h_proto;
 512         *p_nhoff += sizeof(*hdr);
 513
 514         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 515         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 516                 return FLOW_DISSECT_RET_OUT_GOOD;
 517
 518         return FLOW_DISSECT_RET_PROTO_AGAIN;
 519 }
 520
 521 static void
 522 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 523                        struct flow_dissector *flow_dissector,
 524                        void *target_container, void *data, int thoff, int hlen)
 525 {
 526         struct flow_dissector_key_tcp *key_tcp;
 527         struct tcphdr *th, _th;
 528
 529         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 530                 return;
 531
 532         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 533         if (!th)
 534                 return;
 535
 536         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 537                 return;
 538
 539         key_tcp = skb_flow_dissector_target(flow_dissector,
 540                                             FLOW_DISSECTOR_KEY_TCP,
 541                                             target_container);
 542         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 543 }
 544
 545 static void
 546 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 547                         struct flow_dissector *flow_dissector,
 548                         void *target_container, void *data, const struct iphdr *iph)
 549 {
 550         struct flow_dissector_key_ip *key_ip;
 551
 552         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 553                 return;
 554
 555         key_ip = skb_flow_dissector_target(flow_dissector,
 556                                            FLOW_DISSECTOR_KEY_IP,
 557                                            target_container);
 558         key_ip->tos = iph->tos;
 559         key_ip->ttl = iph->ttl;
 560 }
 561
 562 static void
 563 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 564                         struct flow_dissector *flow_dissector,
 565                         void *target_container, void *data, const struct ipv6hdr *iph)
 566 {
 567         struct flow_dissector_key_ip *key_ip;
 568
 569         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 570                 return;
 571
 572         key_ip = skb_flow_dissector_target(flow_dissector,
 573                                            FLOW_DISSECTOR_KEY_IP,
 574                                            target_container);
 575         key_ip->tos = ipv6_get_dsfield(iph);
 576         key_ip->ttl = iph->hop_limit;
 577 }
 578
 579 /* Maximum number of protocol headers that can be parsed in
 580  * __skb_flow_dissect
 581  */
 582 #define MAX_FLOW_DISSECT_HDRS   15
 583
 584 static bool skb_flow_dissect_allowed(int *num_hdrs)
 585 {
 586         ++*num_hdrs;
 587
 588         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 589 }
 590
 591 /**
 592  * __skb_flow_dissect - extract the flow_keys struct and return it
 593  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 594  * @flow_dissector: list of keys to dissect
 595  * @target_container: target structure to put dissected values into
 596  * @data: raw buffer pointer to the packet, if NULL use skb->data
 597  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 598  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 599  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 600  *
 601  * The function will try to retrieve individual keys into target specified
 602  * by flow_dissector from either the skbuff or a raw buffer specified by the
 603  * rest parameters.
 604  *
 605  * Caller must take care of zeroing target container memory.
 606  */
 607 bool __skb_flow_dissect(const struct sk_buff *skb,
 608                         struct flow_dissector *flow_dissector,
 609                         void *target_container,
 610                         void *data, __be16 proto, int nhoff, int hlen,
 611                         unsigned int flags)
 612 {
 613         struct flow_dissector_key_control *key_control;
 614         struct flow_dissector_key_basic *key_basic;
 615         struct flow_dissector_key_addrs *key_addrs;
 616         struct flow_dissector_key_ports *key_ports;
 617         struct flow_dissector_key_icmp *key_icmp;
 618         struct flow_dissector_key_tags *key_tags;
 619         struct flow_dissector_key_vlan *key_vlan;
 620         enum flow_dissect_ret fdret;
 621         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
 622         int num_hdrs = 0;
 623         u8 ip_proto = 0;
 624         bool ret;
 625
 626         if (!data) {
 627                 data = skb->data;
 628                 proto = skb_vlan_tag_present(skb) ?
 629                          skb->vlan_proto : skb->protocol;
 630                 nhoff = skb_network_offset(skb);
 631                 hlen = skb_headlen(skb);
 632 #if IS_ENABLED(CONFIG_NET_DSA)
 633                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
 634                              proto == htons(ETH_P_XDSA))) {
 635                         const struct dsa_device_ops *ops;
 636                         int offset = 0;
 637
 638                         ops = skb->dev->dsa_ptr->tag_ops;
 639                         if (ops->flow_dissect &&
 640                             !ops->flow_dissect(skb, &proto, &offset)) {
 641                                 hlen -= offset;
 642                                 nhoff += offset;
 643                         }
 644                 }
 645 #endif
 646         }
 647
 648         /* It is ensured by skb_flow_dissector_init() that control key will
 649          * be always present.
 650          */
 651         key_control = skb_flow_dissector_target(flow_dissector,
 652                                                 FLOW_DISSECTOR_KEY_CONTROL,
 653                                                 target_container);
 654
 655         /* It is ensured by skb_flow_dissector_init() that basic key will
 656          * be always present.
 657          */
 658         key_basic = skb_flow_dissector_target(flow_dissector,
 659                                               FLOW_DISSECTOR_KEY_BASIC,
 660                                               target_container);
 661
 662         if (dissector_uses_key(flow_dissector,
 663                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 664                 struct ethhdr *eth = eth_hdr(skb);
 665                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 666
 667                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 668                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 669                                                           target_container);
 670                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 671         }
 672
 673 proto_again:
 674         fdret = FLOW_DISSECT_RET_CONTINUE;
 675
 676         switch (proto) {
 677         case htons(ETH_P_IP): {
 678                 const struct iphdr *iph;
 679                 struct iphdr _iph;
 680
 681                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 682                 if (!iph || iph->ihl < 5) {
 683                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 684                         break;
 685                 }
 686
 687                 nhoff += iph->ihl * 4;
 688
 689                 ip_proto = iph->protocol;
 690
 691                 if (dissector_uses_key(flow_dissector,
 692                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 693                         key_addrs = skb_flow_dissector_target(flow_dissector,
 694                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 695                                                               target_container);
 696
 697                         memcpy(&key_addrs->v4addrs.src, &iph->saddr,
 698                                sizeof(key_addrs->v4addrs.src));
 699                         memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
 700                                sizeof(key_addrs->v4addrs.dst));
 701                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 702                 }
 703
 704                 if (ip_is_fragment(iph)) {
 705                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 706
 707                         if (iph->frag_off & htons(IP_OFFSET)) {
 708                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 709                                 break;
 710                         } else {
 711                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 712                                 if (!(flags &
 713                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
 714                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 715                                         break;
 716                                 }
 717                         }
 718                 }
 719
 720                 __skb_flow_dissect_ipv4(skb, flow_dissector,
 721                                         target_container, data, iph);
 722
 723                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
 724                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 725                         break;
 726                 }
 727
 728                 break;
 729         }
 730         case htons(ETH_P_IPV6): {
 731                 const struct ipv6hdr *iph;
 732                 struct ipv6hdr _iph;
 733
 734                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 735                 if (!iph) {
 736                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 737                         break;
 738                 }
 739
 740                 ip_proto = iph->nexthdr;
 741                 nhoff += sizeof(struct ipv6hdr);
 742
 743                 if (dissector_uses_key(flow_dissector,
 744                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 745                         key_addrs = skb_flow_dissector_target(flow_dissector,
 746                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 747                                                               target_container);
 748
 749                         memcpy(&key_addrs->v6addrs.src, &iph->saddr,
 750                                sizeof(key_addrs->v6addrs.src));
 751                         memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
 752                                sizeof(key_addrs->v6addrs.dst));
 753                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 754                 }
 755
 756                 if ((dissector_uses_key(flow_dissector,
 757                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 758                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 759                     ip6_flowlabel(iph)) {
 760                         __be32 flow_label = ip6_flowlabel(iph);
 761
 762                         if (dissector_uses_key(flow_dissector,
 763                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 764                                 key_tags = skb_flow_dissector_target(flow_dissector,
 765                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 766                                                                      target_container);
 767                                 key_tags->flow_label = ntohl(flow_label);
 768                         }
 769                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
 770                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 771                                 break;
 772                         }
 773                 }
 774
 775                 __skb_flow_dissect_ipv6(skb, flow_dissector,
 776                                         target_container, data, iph);
 777
 778                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 779                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 780
 781                 break;
 782         }
 783         case htons(ETH_P_8021AD):
 784         case htons(ETH_P_8021Q): {
 785                 const struct vlan_hdr *vlan = NULL;
 786                 struct vlan_hdr _vlan;
 787                 __be16 saved_vlan_tpid = proto;
 788
 789                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
 790                     skb && skb_vlan_tag_present(skb)) {
 791                         proto = skb->protocol;
 792                 } else {
 793                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 794                                                     data, hlen, &_vlan);
 795                         if (!vlan) {
 796                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 797                                 break;
 798                         }
 799
 800                         proto = vlan->h_vlan_encapsulated_proto;
 801                         nhoff += sizeof(*vlan);
 802                 }
 803
 804                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
 805                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
 806                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
 807                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
 808                 } else {
 809                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 810                         break;
 811                 }
 812
 813                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
 814                         key_vlan = skb_flow_dissector_target(flow_dissector,
 815                                                              dissector_vlan,
 816                                                              target_container);
 817
 818                         if (!vlan) {
 819                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 820                                 key_vlan->vlan_priority =
 821                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 822                         } else {
 823                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 824                                         VLAN_VID_MASK;
 825                                 key_vlan->vlan_priority =
 826                                         (ntohs(vlan->h_vlan_TCI) &
 827                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 828                         }
 829                         key_vlan->vlan_tpid = saved_vlan_tpid;
 830                 }
 831
 832                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 833                 break;
 834         }
 835         case htons(ETH_P_PPP_SES): {
 836                 struct {
 837                         struct pppoe_hdr hdr;
 838                         __be16 proto;
 839                 } *hdr, _hdr;
 840                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 841                 if (!hdr) {
 842                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 843                         break;
 844                 }
 845
 846                 proto = hdr->proto;
 847                 nhoff += PPPOE_SES_HLEN;
 848                 switch (proto) {
 849                 case htons(PPP_IP):
 850                         proto = htons(ETH_P_IP);
 851                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 852                         break;
 853                 case htons(PPP_IPV6):
 854                         proto = htons(ETH_P_IPV6);
 855                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 856                         break;
 857                 default:
 858                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 859                         break;
 860                 }
 861                 break;
 862         }
 863         case htons(ETH_P_TIPC): {
 864                 struct tipc_basic_hdr *hdr, _hdr;
 865
 866                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
 867                                            data, hlen, &_hdr);
 868                 if (!hdr) {
 869                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 870                         break;
 871                 }
 872
 873                 if (dissector_uses_key(flow_dissector,
 874                                        FLOW_DISSECTOR_KEY_TIPC)) {
 875                         key_addrs = skb_flow_dissector_target(flow_dissector,
 876                                                               FLOW_DISSECTOR_KEY_TIPC,
 877                                                               target_container);
 878                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
 879                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
 880                 }
 881                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 882                 break;
 883         }
 884
 885         case htons(ETH_P_MPLS_UC):
 886         case htons(ETH_P_MPLS_MC):
 887                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
 888                                                 target_container, data,
 889                                                 nhoff, hlen);
 890                 break;
 891         case htons(ETH_P_FCOE):
 892                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
 893                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 894                         break;
 895                 }
 896
 897                 nhoff += FCOE_HEADER_LEN;
 898                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 899                 break;
 900
 901         case htons(ETH_P_ARP):
 902         case htons(ETH_P_RARP):
 903                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
 904                                                target_container, data,
 905                                                nhoff, hlen);
 906                 break;
 907
 908         case htons(ETH_P_BATMAN):
 909                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
 910                                                   &proto, &nhoff, hlen, flags);
 911                 break;
 912
 913         default:
 914                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 915                 break;
 916         }
 917
 918         /* Process result of proto processing */
 919         switch (fdret) {
 920         case FLOW_DISSECT_RET_OUT_GOOD:
 921                 goto out_good;
 922         case FLOW_DISSECT_RET_PROTO_AGAIN:
 923                 if (skb_flow_dissect_allowed(&num_hdrs))
 924                         goto proto_again;
 925                 goto out_good;
 926         case FLOW_DISSECT_RET_CONTINUE:
 927         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 928                 break;
 929         case FLOW_DISSECT_RET_OUT_BAD:
 930         default:
 931                 goto out_bad;
 932         }
 933
 934 ip_proto_again:
 935         fdret = FLOW_DISSECT_RET_CONTINUE;
 936
 937         switch (ip_proto) {
 938         case IPPROTO_GRE:
 939                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
 940                                                target_container, data,
 941                                                &proto, &nhoff, &hlen, flags);
 942                 break;
 943
 944         case NEXTHDR_HOP:
 945         case NEXTHDR_ROUTING:
 946         case NEXTHDR_DEST: {
 947                 u8 _opthdr[2], *opthdr;
 948
 949                 if (proto != htons(ETH_P_IPV6))
 950                         break;
 951
 952                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 953                                               data, hlen, &_opthdr);
 954                 if (!opthdr) {
 955                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 956                         break;
 957                 }
 958
 959                 ip_proto = opthdr[0];
 960                 nhoff += (opthdr[1] + 1) << 3;
 961
 962                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 963                 break;
 964         }
 965         case NEXTHDR_FRAGMENT: {
 966                 struct frag_hdr _fh, *fh;
 967
 968                 if (proto != htons(ETH_P_IPV6))
 969                         break;
 970
 971                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 972                                           data, hlen, &_fh);
 973
 974                 if (!fh) {
 975                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 976                         break;
 977                 }
 978
 979                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 980
 981                 nhoff += sizeof(_fh);
 982                 ip_proto = fh->nexthdr;
 983
 984                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 985                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 986                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 987                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 988                                 break;
 989                         }
 990                 }
 991
 992                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 993                 break;
 994         }
 995         case IPPROTO_IPIP:
 996                 proto = htons(ETH_P_IP);
 997
 998                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 999                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1000                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1001                         break;
1002                 }
1003
1004                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1005                 break;
1006
1007         case IPPROTO_IPV6:
1008                 proto = htons(ETH_P_IPV6);
1009
1010                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1011                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1012                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1013                         break;
1014                 }
1015
1016                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1017                 break;
1018
1019
1020         case IPPROTO_MPLS:
1021                 proto = htons(ETH_P_MPLS_UC);
1022                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1023                 break;
1024
1025         case IPPROTO_TCP:
1026                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1027                                        data, nhoff, hlen);
1028                 break;
1029
1030         default:
1031                 break;
1032         }
1033
1034         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1035             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1036                 key_ports = skb_flow_dissector_target(flow_dissector,
1037                                                       FLOW_DISSECTOR_KEY_PORTS,
1038                                                       target_container);
1039                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1040                                                         data, hlen);
1041         }
1042
1043         if (dissector_uses_key(flow_dissector,
1044                                FLOW_DISSECTOR_KEY_ICMP)) {
1045                 key_icmp = skb_flow_dissector_target(flow_dissector,
1046                                                      FLOW_DISSECTOR_KEY_ICMP,
1047                                                      target_container);
1048                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1049         }
1050
1051         /* Process result of IP proto processing */
1052         switch (fdret) {
1053         case FLOW_DISSECT_RET_PROTO_AGAIN:
1054                 if (skb_flow_dissect_allowed(&num_hdrs))
1055                         goto proto_again;
1056                 break;
1057         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1058                 if (skb_flow_dissect_allowed(&num_hdrs))
1059                         goto ip_proto_again;
1060                 break;
1061         case FLOW_DISSECT_RET_OUT_GOOD:
1062         case FLOW_DISSECT_RET_CONTINUE:
1063                 break;
1064         case FLOW_DISSECT_RET_OUT_BAD:
1065         default:
1066                 goto out_bad;
1067         }
1068
1069 out_good:
1070         ret = true;
1071
1072 out:
1073         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1074         key_basic->n_proto = proto;
1075         key_basic->ip_proto = ip_proto;
1076
1077         return ret;
1078
1079 out_bad:
1080         ret = false;
1081         goto out;
1082 }
1083 EXPORT_SYMBOL(__skb_flow_dissect);
1084
1085 static siphash_key_t hashrnd __read_mostly;
1086 static __always_inline void __flow_hash_secret_init(void)
1087 {
1088         net_get_random_once(&hashrnd, sizeof(hashrnd));
1089 }
1090
1091 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1092 {
1093         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1094         return &flow->FLOW_KEYS_HASH_START_FIELD;
1095 }
1096
1097 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1098 {
1099         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1100         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1101                      sizeof(*flow) - sizeof(flow->addrs));
1102
1103         switch (flow->control.addr_type) {
1104         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1105                 diff -= sizeof(flow->addrs.v4addrs);
1106                 break;
1107         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1108                 diff -= sizeof(flow->addrs.v6addrs);
1109                 break;
1110         case FLOW_DISSECTOR_KEY_TIPC:
1111                 diff -= sizeof(flow->addrs.tipckey);
1112                 break;
1113         }
1114         return sizeof(*flow) - diff;
1115 }
1116
1117 __be32 flow_get_u32_src(const struct flow_keys *flow)
1118 {
1119         switch (flow->control.addr_type) {
1120         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1121                 return flow->addrs.v4addrs.src;
1122         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1123                 return (__force __be32)ipv6_addr_hash(
1124                         &flow->addrs.v6addrs.src);
1125         case FLOW_DISSECTOR_KEY_TIPC:
1126                 return flow->addrs.tipckey.key;
1127         default:
1128                 return 0;
1129         }
1130 }
1131 EXPORT_SYMBOL(flow_get_u32_src);
1132
1133 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1134 {
1135         switch (flow->control.addr_type) {
1136         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1137                 return flow->addrs.v4addrs.dst;
1138         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1139                 return (__force __be32)ipv6_addr_hash(
1140                         &flow->addrs.v6addrs.dst);
1141         default:
1142                 return 0;
1143         }
1144 }
1145 EXPORT_SYMBOL(flow_get_u32_dst);
1146
1147 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1148 {
1149         int addr_diff, i;
1150
1151         switch (keys->control.addr_type) {
1152         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1153                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1154                             (__force u32)keys->addrs.v4addrs.src;
1155                 if ((addr_diff < 0) ||
1156                     (addr_diff == 0 &&
1157                      ((__force u16)keys->ports.dst <
1158                       (__force u16)keys->ports.src))) {
1159                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1160                         swap(keys->ports.src, keys->ports.dst);
1161                 }
1162                 break;
1163         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1164                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1165                                    &keys->addrs.v6addrs.src,
1166                                    sizeof(keys->addrs.v6addrs.dst));
1167                 if ((addr_diff < 0) ||
1168                     (addr_diff == 0 &&
1169                      ((__force u16)keys->ports.dst <
1170                       (__force u16)keys->ports.src))) {
1171                         for (i = 0; i < 4; i++)
1172                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1173                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1174                         swap(keys->ports.src, keys->ports.dst);
1175                 }
1176                 break;
1177         }
1178 }
1179
1180 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1181                                         const siphash_key_t *keyval)
1182 {
1183         u32 hash;
1184
1185         __flow_hash_consistentify(keys);
1186
1187         hash = siphash(flow_keys_hash_start(keys),
1188                        flow_keys_hash_length(keys), keyval);
1189         if (!hash)
1190                 hash = 1;
1191
1192         return hash;
1193 }
1194
1195 u32 flow_hash_from_keys(struct flow_keys *keys)
1196 {
1197         __flow_hash_secret_init();
1198         return __flow_hash_from_keys(keys, &hashrnd);
1199 }
1200 EXPORT_SYMBOL(flow_hash_from_keys);
1201
1202 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1203                                   struct flow_keys *keys,
1204                                   const siphash_key_t *keyval)
1205 {
1206         skb_flow_dissect_flow_keys(skb, keys,
1207                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1208
1209         return __flow_hash_from_keys(keys, keyval);
1210 }
1211
1212 struct _flow_keys_digest_data {
1213         __be16  n_proto;
1214         u8      ip_proto;
1215         u8      padding;
1216         __be32  ports;
1217         __be32  src;
1218         __be32  dst;
1219 };
1220
1221 void make_flow_keys_digest(struct flow_keys_digest *digest,
1222                            const struct flow_keys *flow)
1223 {
1224         struct _flow_keys_digest_data *data =
1225             (struct _flow_keys_digest_data *)digest;
1226
1227         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1228
1229         memset(digest, 0, sizeof(*digest));
1230
1231         data->n_proto = flow->basic.n_proto;
1232         data->ip_proto = flow->basic.ip_proto;
1233         data->ports = flow->ports.ports;
1234         data->src = flow->addrs.v4addrs.src;
1235         data->dst = flow->addrs.v4addrs.dst;
1236 }
1237 EXPORT_SYMBOL(make_flow_keys_digest);
1238
1239 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1240
1241 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1242 {
1243         struct flow_keys keys;
1244
1245         __flow_hash_secret_init();
1246
1247         memset(&keys, 0, sizeof(keys));
1248         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1249                            NULL, 0, 0, 0,
1250                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1251
1252         return __flow_hash_from_keys(&keys, &hashrnd);
1253 }
1254 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1255
1256 /**
1257  * __skb_get_hash: calculate a flow hash
1258  * @skb: sk_buff to calculate flow hash from
1259  *
1260  * This function calculates a flow hash based on src/dst addresses
1261  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1262  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1263  * if hash is a canonical 4-tuple hash over transport ports.
1264  */
1265 void __skb_get_hash(struct sk_buff *skb)
1266 {
1267         struct flow_keys keys;
1268         u32 hash;
1269
1270         __flow_hash_secret_init();
1271
1272         hash = ___skb_get_hash(skb, &keys, &hashrnd);
1273
1274         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1275 }
1276 EXPORT_SYMBOL(__skb_get_hash);
1277
1278 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1279                            const siphash_key_t *perturb)
1280 {
1281         struct flow_keys keys;
1282
1283         return ___skb_get_hash(skb, &keys, perturb);
1284 }
1285 EXPORT_SYMBOL(skb_get_hash_perturb);
1286
1287 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1288                    const struct flow_keys_basic *keys, int hlen)
1289 {
1290         u32 poff = keys->control.thoff;
1291
1292         /* skip L4 headers for fragments after the first */
1293         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1294             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1295                 return poff;
1296
1297         switch (keys->basic.ip_proto) {
1298         case IPPROTO_TCP: {
1299                 /* access doff as u8 to avoid unaligned access */
1300                 const u8 *doff;
1301                 u8 _doff;
1302
1303                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1304                                             data, hlen, &_doff);
1305                 if (!doff)
1306                         return poff;
1307
1308                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1309                 break;
1310         }
1311         case IPPROTO_UDP:
1312         case IPPROTO_UDPLITE:
1313                 poff += sizeof(struct udphdr);
1314                 break;
1315         /* For the rest, we do not really care about header
1316          * extensions at this point for now.
1317          */
1318         case IPPROTO_ICMP:
1319                 poff += sizeof(struct icmphdr);
1320                 break;
1321         case IPPROTO_ICMPV6:
1322                 poff += sizeof(struct icmp6hdr);
1323                 break;
1324         case IPPROTO_IGMP:
1325                 poff += sizeof(struct igmphdr);
1326                 break;
1327         case IPPROTO_DCCP:
1328                 poff += sizeof(struct dccp_hdr);
1329                 break;
1330         case IPPROTO_SCTP:
1331                 poff += sizeof(struct sctphdr);
1332                 break;
1333         }
1334
1335         return poff;
1336 }
1337
1338 /**
1339  * skb_get_poff - get the offset to the payload
1340  * @skb: sk_buff to get the payload offset from
1341  *
1342  * The function will get the offset to the payload as far as it could
1343  * be dissected.  The main user is currently BPF, so that we can dynamically
1344  * truncate packets without needing to push actual payload to the user
1345  * space and can analyze headers only, instead.
1346  */
1347 u32 skb_get_poff(const struct sk_buff *skb)
1348 {
1349         struct flow_keys_basic keys;
1350
1351         if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
1352                 return 0;
1353
1354         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1355 }
1356
1357 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1358 {
1359         memset(keys, 0, sizeof(*keys));
1360
1361         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1362             sizeof(keys->addrs.v6addrs.src));
1363         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1364             sizeof(keys->addrs.v6addrs.dst));
1365         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1366         keys->ports.src = fl6->fl6_sport;
1367         keys->ports.dst = fl6->fl6_dport;
1368         keys->keyid.keyid = fl6->fl6_gre_key;
1369         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1370         keys->basic.ip_proto = fl6->flowi6_proto;
1371
1372         return flow_hash_from_keys(keys);
1373 }
1374 EXPORT_SYMBOL(__get_hash_from_flowi6);
1375
1376 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1377         {
1378                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1379                 .offset = offsetof(struct flow_keys, control),
1380         },
1381         {
1382                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1383                 .offset = offsetof(struct flow_keys, basic),
1384         },
1385         {
1386                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1387                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1388         },
1389         {
1390                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1391                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1392         },
1393         {
1394                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1395                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1396         },
1397         {
1398                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1399                 .offset = offsetof(struct flow_keys, ports),
1400         },
1401         {
1402                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1403                 .offset = offsetof(struct flow_keys, vlan),
1404         },
1405         {
1406                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1407                 .offset = offsetof(struct flow_keys, tags),
1408         },
1409         {
1410                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1411                 .offset = offsetof(struct flow_keys, keyid),
1412         },
1413 };
1414
1415 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1416         {
1417                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1418                 .offset = offsetof(struct flow_keys, control),
1419         },
1420         {
1421                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1422                 .offset = offsetof(struct flow_keys, basic),
1423         },
1424         {
1425                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1426                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1427         },
1428         {
1429                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1430                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1431         },
1432         {
1433                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1434                 .offset = offsetof(struct flow_keys, ports),
1435         },
1436 };
1437
1438 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1439         {
1440                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1441                 .offset = offsetof(struct flow_keys, control),
1442         },
1443         {
1444                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1445                 .offset = offsetof(struct flow_keys, basic),
1446         },
1447 };
1448
1449 struct flow_dissector flow_keys_dissector __read_mostly;
1450 EXPORT_SYMBOL(flow_keys_dissector);
1451
1452 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1453 EXPORT_SYMBOL(flow_keys_basic_dissector);
1454
1455 static int __init init_default_flow_dissectors(void)
1456 {
1457         skb_flow_dissector_init(&flow_keys_dissector,
1458                                 flow_keys_dissector_keys,
1459                                 ARRAY_SIZE(flow_keys_dissector_keys));
1460         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1461                                 flow_keys_dissector_symmetric_keys,
1462                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1463         skb_flow_dissector_init(&flow_keys_basic_dissector,
1464                                 flow_keys_basic_dissector_keys,
1465                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1466         return 0;
1467 }
1468
1469 core_initcall(init_default_flow_dissectors);