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                 return;
 157
 158         info = skb_tunnel_info(skb);
 159         if (!info)
 160                 return;
 161
 162         key = &info->key;
 163
 164         switch (ip_tunnel_info_af(info)) {
 165         case AF_INET:
 166                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 167                                                    flow_dissector,
 168                                                    target_container);
 169                 if (dissector_uses_key(flow_dissector,
 170                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 171                         struct flow_dissector_key_ipv4_addrs *ipv4;
 172
 173                         ipv4 = skb_flow_dissector_target(flow_dissector,
 174                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 175                                                          target_container);
 176                         ipv4->src = key->u.ipv4.src;
 177                         ipv4->dst = key->u.ipv4.dst;
 178                 }
 179                 break;
 180         case AF_INET6:
 181                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 182                                                    flow_dissector,
 183                                                    target_container);
 184                 if (dissector_uses_key(flow_dissector,
 185                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 186                         struct flow_dissector_key_ipv6_addrs *ipv6;
 187
 188                         ipv6 = skb_flow_dissector_target(flow_dissector,
 189                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 190                                                          target_container);
 191                         ipv6->src = key->u.ipv6.src;
 192                         ipv6->dst = key->u.ipv6.dst;
 193                 }
 194                 break;
 195         }
 196
 197         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 198                 struct flow_dissector_key_keyid *keyid;
 199
 200                 keyid = skb_flow_dissector_target(flow_dissector,
 201                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
 202                                                   target_container);
 203                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
 204         }
 205
 206         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 207                 struct flow_dissector_key_ports *tp;
 208
 209                 tp = skb_flow_dissector_target(flow_dissector,
 210                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
 211                                                target_container);
 212                 tp->src = key->tp_src;
 213                 tp->dst = key->tp_dst;
 214         }
 215 }
 216 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 217
 218 static enum flow_dissect_ret
 219 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 220                         struct flow_dissector *flow_dissector,
 221                         void *target_container, void *data, int nhoff, int hlen)
 222 {
 223         struct flow_dissector_key_keyid *key_keyid;
 224         struct mpls_label *hdr, _hdr[2];
 225         u32 entry, label;
 226
 227         if (!dissector_uses_key(flow_dissector,
 228                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 229             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 230                 return FLOW_DISSECT_RET_OUT_GOOD;
 231
 232         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 233                                    hlen, &_hdr);
 234         if (!hdr)
 235                 return FLOW_DISSECT_RET_OUT_BAD;
 236
 237         entry = ntohl(hdr[0].entry);
 238         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 239
 240         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 241                 struct flow_dissector_key_mpls *key_mpls;
 242
 243                 key_mpls = skb_flow_dissector_target(flow_dissector,
 244                                                      FLOW_DISSECTOR_KEY_MPLS,
 245                                                      target_container);
 246                 key_mpls->mpls_label = label;
 247                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
 248                                         >> MPLS_LS_TTL_SHIFT;
 249                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
 250                                         >> MPLS_LS_TC_SHIFT;
 251                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
 252                                         >> MPLS_LS_S_SHIFT;
 253         }
 254
 255         if (label == MPLS_LABEL_ENTROPY) {
 256                 key_keyid = skb_flow_dissector_target(flow_dissector,
 257                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 258                                                       target_container);
 259                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
 260         }
 261         return FLOW_DISSECT_RET_OUT_GOOD;
 262 }
 263
 264 static enum flow_dissect_ret
 265 __skb_flow_dissect_arp(const struct sk_buff *skb,
 266                        struct flow_dissector *flow_dissector,
 267                        void *target_container, void *data, int nhoff, int hlen)
 268 {
 269         struct flow_dissector_key_arp *key_arp;
 270         struct {
 271                 unsigned char ar_sha[ETH_ALEN];
 272                 unsigned char ar_sip[4];
 273                 unsigned char ar_tha[ETH_ALEN];
 274                 unsigned char ar_tip[4];
 275         } *arp_eth, _arp_eth;
 276         const struct arphdr *arp;
 277         struct arphdr _arp;
 278
 279         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 280                 return FLOW_DISSECT_RET_OUT_GOOD;
 281
 282         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 283                                    hlen, &_arp);
 284         if (!arp)
 285                 return FLOW_DISSECT_RET_OUT_BAD;
 286
 287         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 288             arp->ar_pro != htons(ETH_P_IP) ||
 289             arp->ar_hln != ETH_ALEN ||
 290             arp->ar_pln != 4 ||
 291             (arp->ar_op != htons(ARPOP_REPLY) &&
 292              arp->ar_op != htons(ARPOP_REQUEST)))
 293                 return FLOW_DISSECT_RET_OUT_BAD;
 294
 295         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 296                                        sizeof(_arp_eth), data,
 297                                        hlen, &_arp_eth);
 298         if (!arp_eth)
 299                 return FLOW_DISSECT_RET_OUT_BAD;
 300
 301         key_arp = skb_flow_dissector_target(flow_dissector,
 302                                             FLOW_DISSECTOR_KEY_ARP,
 303                                             target_container);
 304
 305         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 306         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 307
 308         /* Only store the lower byte of the opcode;
 309          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 310          */
 311         key_arp->op = ntohs(arp->ar_op) & 0xff;
 312
 313         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 314         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 315
 316         return FLOW_DISSECT_RET_OUT_GOOD;
 317 }
 318
 319 static enum flow_dissect_ret
 320 __skb_flow_dissect_gre(const struct sk_buff *skb,
 321                        struct flow_dissector_key_control *key_control,
 322                        struct flow_dissector *flow_dissector,
 323                        void *target_container, void *data,
 324                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 325                        unsigned int flags)
 326 {
 327         struct flow_dissector_key_keyid *key_keyid;
 328         struct gre_base_hdr *hdr, _hdr;
 329         int offset = 0;
 330         u16 gre_ver;
 331
 332         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 333                                    data, *p_hlen, &_hdr);
 334         if (!hdr)
 335                 return FLOW_DISSECT_RET_OUT_BAD;
 336
 337         /* Only look inside GRE without routing */
 338         if (hdr->flags & GRE_ROUTING)
 339                 return FLOW_DISSECT_RET_OUT_GOOD;
 340
 341         /* Only look inside GRE for version 0 and 1 */
 342         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 343         if (gre_ver > 1)
 344                 return FLOW_DISSECT_RET_OUT_GOOD;
 345
 346         *p_proto = hdr->protocol;
 347         if (gre_ver) {
 348                 /* Version1 must be PPTP, and check the flags */
 349                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 350                         return FLOW_DISSECT_RET_OUT_GOOD;
 351         }
 352
 353         offset += sizeof(struct gre_base_hdr);
 354
 355         if (hdr->flags & GRE_CSUM)
 356                 offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
 357                           sizeof(((struct gre_full_hdr *) 0)->reserved1);
 358
 359         if (hdr->flags & GRE_KEY) {
 360                 const __be32 *keyid;
 361                 __be32 _keyid;
 362
 363                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 364                                              sizeof(_keyid),
 365                                              data, *p_hlen, &_keyid);
 366                 if (!keyid)
 367                         return FLOW_DISSECT_RET_OUT_BAD;
 368
 369                 if (dissector_uses_key(flow_dissector,
 370                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 371                         key_keyid = skb_flow_dissector_target(flow_dissector,
 372                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 373                                                               target_container);
 374                         if (gre_ver == 0)
 375                                 key_keyid->keyid = *keyid;
 376                         else
 377                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 378                 }
 379                 offset += sizeof(((struct gre_full_hdr *) 0)->key);
 380         }
 381
 382         if (hdr->flags & GRE_SEQ)
 383                 offset += sizeof(((struct pptp_gre_header *) 0)->seq);
 384
 385         if (gre_ver == 0) {
 386                 if (*p_proto == htons(ETH_P_TEB)) {
 387                         const struct ethhdr *eth;
 388                         struct ethhdr _eth;
 389
 390                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 391                                                    sizeof(_eth),
 392                                                    data, *p_hlen, &_eth);
 393                         if (!eth)
 394                                 return FLOW_DISSECT_RET_OUT_BAD;
 395                         *p_proto = eth->h_proto;
 396                         offset += sizeof(*eth);
 397
 398                         /* Cap headers that we access via pointers at the
 399                          * end of the Ethernet header as our maximum alignment
 400                          * at that point is only 2 bytes.
 401                          */
 402                         if (NET_IP_ALIGN)
 403                                 *p_hlen = *p_nhoff + offset;
 404                 }
 405         } else { /* version 1, must be PPTP */
 406                 u8 _ppp_hdr[PPP_HDRLEN];
 407                 u8 *ppp_hdr;
 408
 409                 if (hdr->flags & GRE_ACK)
 410                         offset += sizeof(((struct pptp_gre_header *) 0)->ack);
 411
 412                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 413                                                sizeof(_ppp_hdr),
 414                                                data, *p_hlen, _ppp_hdr);
 415                 if (!ppp_hdr)
 416                         return FLOW_DISSECT_RET_OUT_BAD;
 417
 418                 switch (PPP_PROTOCOL(ppp_hdr)) {
 419                 case PPP_IP:
 420                         *p_proto = htons(ETH_P_IP);
 421                         break;
 422                 case PPP_IPV6:
 423                         *p_proto = htons(ETH_P_IPV6);
 424                         break;
 425                 default:
 426                         /* Could probably catch some more like MPLS */
 427                         break;
 428                 }
 429
 430                 offset += PPP_HDRLEN;
 431         }
 432
 433         *p_nhoff += offset;
 434         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 435         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 436                 return FLOW_DISSECT_RET_OUT_GOOD;
 437
 438         return FLOW_DISSECT_RET_PROTO_AGAIN;
 439 }
 440
 441 /**
 442  * __skb_flow_dissect_batadv() - dissect batman-adv header
 443  * @skb: sk_buff to with the batman-adv header
 444  * @key_control: flow dissectors control key
 445  * @data: raw buffer pointer to the packet, if NULL use skb->data
 446  * @p_proto: pointer used to update the protocol to process next
 447  * @p_nhoff: pointer used to update inner network header offset
 448  * @hlen: packet header length
 449  * @flags: any combination of FLOW_DISSECTOR_F_*
 450  *
 451  * ETH_P_BATMAN packets are tried to be dissected. Only
 452  * &struct batadv_unicast packets are actually processed because they contain an
 453  * inner ethernet header and are usually followed by actual network header. This
 454  * allows the flow dissector to continue processing the packet.
 455  *
 456  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 457  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 458  *  otherwise FLOW_DISSECT_RET_OUT_BAD
 459  */
 460 static enum flow_dissect_ret
 461 __skb_flow_dissect_batadv(const struct sk_buff *skb,
 462                           struct flow_dissector_key_control *key_control,
 463                           void *data, __be16 *p_proto, int *p_nhoff, int hlen,
 464                           unsigned int flags)
 465 {
 466         struct {
 467                 struct batadv_unicast_packet batadv_unicast;
 468                 struct ethhdr eth;
 469         } *hdr, _hdr;
 470
 471         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 472                                    &_hdr);
 473         if (!hdr)
 474                 return FLOW_DISSECT_RET_OUT_BAD;
 475
 476         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 477                 return FLOW_DISSECT_RET_OUT_BAD;
 478
 479         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 480                 return FLOW_DISSECT_RET_OUT_BAD;
 481
 482         *p_proto = hdr->eth.h_proto;
 483         *p_nhoff += sizeof(*hdr);
 484
 485         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 486         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 487                 return FLOW_DISSECT_RET_OUT_GOOD;
 488
 489         return FLOW_DISSECT_RET_PROTO_AGAIN;
 490 }
 491
 492 static void
 493 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 494                        struct flow_dissector *flow_dissector,
 495                        void *target_container, void *data, int thoff, int hlen)
 496 {
 497         struct flow_dissector_key_tcp *key_tcp;
 498         struct tcphdr *th, _th;
 499
 500         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 501                 return;
 502
 503         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 504         if (!th)
 505                 return;
 506
 507         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 508                 return;
 509
 510         key_tcp = skb_flow_dissector_target(flow_dissector,
 511                                             FLOW_DISSECTOR_KEY_TCP,
 512                                             target_container);
 513         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 514 }
 515
 516 static void
 517 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 518                         struct flow_dissector *flow_dissector,
 519                         void *target_container, void *data, const struct iphdr *iph)
 520 {
 521         struct flow_dissector_key_ip *key_ip;
 522
 523         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 524                 return;
 525
 526         key_ip = skb_flow_dissector_target(flow_dissector,
 527                                            FLOW_DISSECTOR_KEY_IP,
 528                                            target_container);
 529         key_ip->tos = iph->tos;
 530         key_ip->ttl = iph->ttl;
 531 }
 532
 533 static void
 534 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 535                         struct flow_dissector *flow_dissector,
 536                         void *target_container, void *data, const struct ipv6hdr *iph)
 537 {
 538         struct flow_dissector_key_ip *key_ip;
 539
 540         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 541                 return;
 542
 543         key_ip = skb_flow_dissector_target(flow_dissector,
 544                                            FLOW_DISSECTOR_KEY_IP,
 545                                            target_container);
 546         key_ip->tos = ipv6_get_dsfield(iph);
 547         key_ip->ttl = iph->hop_limit;
 548 }
 549
 550 /* Maximum number of protocol headers that can be parsed in
 551  * __skb_flow_dissect
 552  */
 553 #define MAX_FLOW_DISSECT_HDRS   15
 554
 555 static bool skb_flow_dissect_allowed(int *num_hdrs)
 556 {
 557         ++*num_hdrs;
 558
 559         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 560 }
 561
 562 /**
 563  * __skb_flow_dissect - extract the flow_keys struct and return it
 564  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 565  * @flow_dissector: list of keys to dissect
 566  * @target_container: target structure to put dissected values into
 567  * @data: raw buffer pointer to the packet, if NULL use skb->data
 568  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 569  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 570  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 571  *
 572  * The function will try to retrieve individual keys into target specified
 573  * by flow_dissector from either the skbuff or a raw buffer specified by the
 574  * rest parameters.
 575  *
 576  * Caller must take care of zeroing target container memory.
 577  */
 578 bool __skb_flow_dissect(const struct sk_buff *skb,
 579                         struct flow_dissector *flow_dissector,
 580                         void *target_container,
 581                         void *data, __be16 proto, int nhoff, int hlen,
 582                         unsigned int flags)
 583 {
 584         struct flow_dissector_key_control *key_control;
 585         struct flow_dissector_key_basic *key_basic;
 586         struct flow_dissector_key_addrs *key_addrs;
 587         struct flow_dissector_key_ports *key_ports;
 588         struct flow_dissector_key_icmp *key_icmp;
 589         struct flow_dissector_key_tags *key_tags;
 590         struct flow_dissector_key_vlan *key_vlan;
 591         enum flow_dissect_ret fdret;
 592         bool skip_vlan = false;
 593         int num_hdrs = 0;
 594         u8 ip_proto = 0;
 595         bool ret;
 596
 597         if (!data) {
 598                 data = skb->data;
 599                 proto = skb_vlan_tag_present(skb) ?
 600                          skb->vlan_proto : skb->protocol;
 601                 nhoff = skb_network_offset(skb);
 602                 hlen = skb_headlen(skb);
 603 #if IS_ENABLED(CONFIG_NET_DSA)
 604                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
 605                         const struct dsa_device_ops *ops;
 606                         int offset;
 607
 608                         ops = skb->dev->dsa_ptr->tag_ops;
 609                         if (ops->flow_dissect &&
 610                             !ops->flow_dissect(skb, &proto, &offset)) {
 611                                 hlen -= offset;
 612                                 nhoff += offset;
 613                         }
 614                 }
 615 #endif
 616         }
 617
 618         /* It is ensured by skb_flow_dissector_init() that control key will
 619          * be always present.
 620          */
 621         key_control = skb_flow_dissector_target(flow_dissector,
 622                                                 FLOW_DISSECTOR_KEY_CONTROL,
 623                                                 target_container);
 624
 625         /* It is ensured by skb_flow_dissector_init() that basic key will
 626          * be always present.
 627          */
 628         key_basic = skb_flow_dissector_target(flow_dissector,
 629                                               FLOW_DISSECTOR_KEY_BASIC,
 630                                               target_container);
 631
 632         if (dissector_uses_key(flow_dissector,
 633                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 634                 struct ethhdr *eth = eth_hdr(skb);
 635                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 636
 637                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 638                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 639                                                           target_container);
 640                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 641         }
 642
 643 proto_again:
 644         fdret = FLOW_DISSECT_RET_CONTINUE;
 645
 646         switch (proto) {
 647         case htons(ETH_P_IP): {
 648                 const struct iphdr *iph;
 649                 struct iphdr _iph;
 650
 651                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 652                 if (!iph || iph->ihl < 5) {
 653                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 654                         break;
 655                 }
 656
 657                 nhoff += iph->ihl * 4;
 658
 659                 ip_proto = iph->protocol;
 660
 661                 if (dissector_uses_key(flow_dissector,
 662                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 663                         key_addrs = skb_flow_dissector_target(flow_dissector,
 664                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 665                                                               target_container);
 666
 667                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 668                                sizeof(key_addrs->v4addrs));
 669                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 670                 }
 671
 672                 if (ip_is_fragment(iph)) {
 673                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 674
 675                         if (iph->frag_off & htons(IP_OFFSET)) {
 676                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 677                                 break;
 678                         } else {
 679                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 680                                 if (!(flags &
 681                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
 682                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 683                                         break;
 684                                 }
 685                         }
 686                 }
 687
 688                 __skb_flow_dissect_ipv4(skb, flow_dissector,
 689                                         target_container, data, iph);
 690
 691                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
 692                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 693                         break;
 694                 }
 695
 696                 break;
 697         }
 698         case htons(ETH_P_IPV6): {
 699                 const struct ipv6hdr *iph;
 700                 struct ipv6hdr _iph;
 701
 702                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 703                 if (!iph) {
 704                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 705                         break;
 706                 }
 707
 708                 ip_proto = iph->nexthdr;
 709                 nhoff += sizeof(struct ipv6hdr);
 710
 711                 if (dissector_uses_key(flow_dissector,
 712                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 713                         key_addrs = skb_flow_dissector_target(flow_dissector,
 714                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 715                                                               target_container);
 716
 717                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 718                                sizeof(key_addrs->v6addrs));
 719                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 720                 }
 721
 722                 if ((dissector_uses_key(flow_dissector,
 723                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 724                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 725                     ip6_flowlabel(iph)) {
 726                         __be32 flow_label = ip6_flowlabel(iph);
 727
 728                         if (dissector_uses_key(flow_dissector,
 729                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 730                                 key_tags = skb_flow_dissector_target(flow_dissector,
 731                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 732                                                                      target_container);
 733                                 key_tags->flow_label = ntohl(flow_label);
 734                         }
 735                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
 736                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 737                                 break;
 738                         }
 739                 }
 740
 741                 __skb_flow_dissect_ipv6(skb, flow_dissector,
 742                                         target_container, data, iph);
 743
 744                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 745                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 746
 747                 break;
 748         }
 749         case htons(ETH_P_8021AD):
 750         case htons(ETH_P_8021Q): {
 751                 const struct vlan_hdr *vlan;
 752                 struct vlan_hdr _vlan;
 753                 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
 754                 __be16 saved_vlan_tpid = proto;
 755
 756                 if (vlan_tag_present)
 757                         proto = skb->protocol;
 758
 759                 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
 760                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 761                                                     data, hlen, &_vlan);
 762                         if (!vlan) {
 763                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 764                                 break;
 765                         }
 766
 767                         proto = vlan->h_vlan_encapsulated_proto;
 768                         nhoff += sizeof(*vlan);
 769                         if (skip_vlan) {
 770                                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 771                                 break;
 772                         }
 773                 }
 774
 775                 skip_vlan = true;
 776                 if (dissector_uses_key(flow_dissector,
 777                                        FLOW_DISSECTOR_KEY_VLAN)) {
 778                         key_vlan = skb_flow_dissector_target(flow_dissector,
 779                                                              FLOW_DISSECTOR_KEY_VLAN,
 780                                                              target_container);
 781
 782                         if (vlan_tag_present) {
 783                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 784                                 key_vlan->vlan_priority =
 785                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 786                         } else {
 787                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 788                                         VLAN_VID_MASK;
 789                                 key_vlan->vlan_priority =
 790                                         (ntohs(vlan->h_vlan_TCI) &
 791                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 792                         }
 793                         key_vlan->vlan_tpid = saved_vlan_tpid;
 794                 }
 795
 796                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 797                 break;
 798         }
 799         case htons(ETH_P_PPP_SES): {
 800                 struct {
 801                         struct pppoe_hdr hdr;
 802                         __be16 proto;
 803                 } *hdr, _hdr;
 804                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 805                 if (!hdr) {
 806                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 807                         break;
 808                 }
 809
 810                 proto = hdr->proto;
 811                 nhoff += PPPOE_SES_HLEN;
 812                 switch (proto) {
 813                 case htons(PPP_IP):
 814                         proto = htons(ETH_P_IP);
 815                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 816                         break;
 817                 case htons(PPP_IPV6):
 818                         proto = htons(ETH_P_IPV6);
 819                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 820                         break;
 821                 default:
 822                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 823                         break;
 824                 }
 825                 break;
 826         }
 827         case htons(ETH_P_TIPC): {
 828                 struct tipc_basic_hdr *hdr, _hdr;
 829
 830                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
 831                                            data, hlen, &_hdr);
 832                 if (!hdr) {
 833                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 834                         break;
 835                 }
 836
 837                 if (dissector_uses_key(flow_dissector,
 838                                        FLOW_DISSECTOR_KEY_TIPC)) {
 839                         key_addrs = skb_flow_dissector_target(flow_dissector,
 840                                                               FLOW_DISSECTOR_KEY_TIPC,
 841                                                               target_container);
 842                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
 843                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
 844                 }
 845                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 846                 break;
 847         }
 848
 849         case htons(ETH_P_MPLS_UC):
 850         case htons(ETH_P_MPLS_MC):
 851                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
 852                                                 target_container, data,
 853                                                 nhoff, hlen);
 854                 break;
 855         case htons(ETH_P_FCOE):
 856                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
 857                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 858                         break;
 859                 }
 860
 861                 nhoff += FCOE_HEADER_LEN;
 862                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 863                 break;
 864
 865         case htons(ETH_P_ARP):
 866         case htons(ETH_P_RARP):
 867                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
 868                                                target_container, data,
 869                                                nhoff, hlen);
 870                 break;
 871
 872         case htons(ETH_P_BATMAN):
 873                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
 874                                                   &proto, &nhoff, hlen, flags);
 875                 break;
 876
 877         default:
 878                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 879                 break;
 880         }
 881
 882         /* Process result of proto processing */
 883         switch (fdret) {
 884         case FLOW_DISSECT_RET_OUT_GOOD:
 885                 goto out_good;
 886         case FLOW_DISSECT_RET_PROTO_AGAIN:
 887                 if (skb_flow_dissect_allowed(&num_hdrs))
 888                         goto proto_again;
 889                 goto out_good;
 890         case FLOW_DISSECT_RET_CONTINUE:
 891         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 892                 break;
 893         case FLOW_DISSECT_RET_OUT_BAD:
 894         default:
 895                 goto out_bad;
 896         }
 897
 898 ip_proto_again:
 899         fdret = FLOW_DISSECT_RET_CONTINUE;
 900
 901         switch (ip_proto) {
 902         case IPPROTO_GRE:
 903                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
 904                                                target_container, data,
 905                                                &proto, &nhoff, &hlen, flags);
 906                 break;
 907
 908         case NEXTHDR_HOP:
 909         case NEXTHDR_ROUTING:
 910         case NEXTHDR_DEST: {
 911                 u8 _opthdr[2], *opthdr;
 912
 913                 if (proto != htons(ETH_P_IPV6))
 914                         break;
 915
 916                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 917                                               data, hlen, &_opthdr);
 918                 if (!opthdr) {
 919                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 920                         break;
 921                 }
 922
 923                 ip_proto = opthdr[0];
 924                 nhoff += (opthdr[1] + 1) << 3;
 925
 926                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 927                 break;
 928         }
 929         case NEXTHDR_FRAGMENT: {
 930                 struct frag_hdr _fh, *fh;
 931
 932                 if (proto != htons(ETH_P_IPV6))
 933                         break;
 934
 935                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 936                                           data, hlen, &_fh);
 937
 938                 if (!fh) {
 939                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 940                         break;
 941                 }
 942
 943                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 944
 945                 nhoff += sizeof(_fh);
 946                 ip_proto = fh->nexthdr;
 947
 948                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 949                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 950                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 951                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 952                                 break;
 953                         }
 954                 }
 955
 956                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 957                 break;
 958         }
 959         case IPPROTO_IPIP:
 960                 proto = htons(ETH_P_IP);
 961
 962                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 963                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 964                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 965                         break;
 966                 }
 967
 968                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 969                 break;
 970
 971         case IPPROTO_IPV6:
 972                 proto = htons(ETH_P_IPV6);
 973
 974                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 975                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 976                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 977                         break;
 978                 }
 979
 980                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 981                 break;
 982
 983
 984         case IPPROTO_MPLS:
 985                 proto = htons(ETH_P_MPLS_UC);
 986                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 987                 break;
 988
 989         case IPPROTO_TCP:
 990                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
 991                                        data, nhoff, hlen);
 992                 break;
 993
 994         default:
 995                 break;
 996         }
 997
 998         if (dissector_uses_key(flow_dissector,
 999                                FLOW_DISSECTOR_KEY_PORTS)) {
1000                 key_ports = skb_flow_dissector_target(flow_dissector,
1001                                                       FLOW_DISSECTOR_KEY_PORTS,
1002                                                       target_container);
1003                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1004                                                         data, hlen);
1005         }
1006
1007         if (dissector_uses_key(flow_dissector,
1008                                FLOW_DISSECTOR_KEY_ICMP)) {
1009                 key_icmp = skb_flow_dissector_target(flow_dissector,
1010                                                      FLOW_DISSECTOR_KEY_ICMP,
1011                                                      target_container);
1012                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1013         }
1014
1015         /* Process result of IP proto processing */
1016         switch (fdret) {
1017         case FLOW_DISSECT_RET_PROTO_AGAIN:
1018                 if (skb_flow_dissect_allowed(&num_hdrs))
1019                         goto proto_again;
1020                 break;
1021         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1022                 if (skb_flow_dissect_allowed(&num_hdrs))
1023                         goto ip_proto_again;
1024                 break;
1025         case FLOW_DISSECT_RET_OUT_GOOD:
1026         case FLOW_DISSECT_RET_CONTINUE:
1027                 break;
1028         case FLOW_DISSECT_RET_OUT_BAD:
1029         default:
1030                 goto out_bad;
1031         }
1032
1033 out_good:
1034         ret = true;
1035
1036 out:
1037         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1038         key_basic->n_proto = proto;
1039         key_basic->ip_proto = ip_proto;
1040
1041         return ret;
1042
1043 out_bad:
1044         ret = false;
1045         goto out;
1046 }
1047 EXPORT_SYMBOL(__skb_flow_dissect);
1048
1049 static u32 hashrnd __read_mostly;
1050 static __always_inline void __flow_hash_secret_init(void)
1051 {
1052         net_get_random_once(&hashrnd, sizeof(hashrnd));
1053 }
1054
1055 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
1056                                              u32 keyval)
1057 {
1058         return jhash2(words, length, keyval);
1059 }
1060
1061 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1062 {
1063         const void *p = flow;
1064
1065         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1066         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1067 }
1068
1069 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1070 {
1071         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1072         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1073         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1074                      sizeof(*flow) - sizeof(flow->addrs));
1075
1076         switch (flow->control.addr_type) {
1077         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1078                 diff -= sizeof(flow->addrs.v4addrs);
1079                 break;
1080         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1081                 diff -= sizeof(flow->addrs.v6addrs);
1082                 break;
1083         case FLOW_DISSECTOR_KEY_TIPC:
1084                 diff -= sizeof(flow->addrs.tipckey);
1085                 break;
1086         }
1087         return (sizeof(*flow) - diff) / sizeof(u32);
1088 }
1089
1090 __be32 flow_get_u32_src(const struct flow_keys *flow)
1091 {
1092         switch (flow->control.addr_type) {
1093         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1094                 return flow->addrs.v4addrs.src;
1095         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1096                 return (__force __be32)ipv6_addr_hash(
1097                         &flow->addrs.v6addrs.src);
1098         case FLOW_DISSECTOR_KEY_TIPC:
1099                 return flow->addrs.tipckey.key;
1100         default:
1101                 return 0;
1102         }
1103 }
1104 EXPORT_SYMBOL(flow_get_u32_src);
1105
1106 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1107 {
1108         switch (flow->control.addr_type) {
1109         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1110                 return flow->addrs.v4addrs.dst;
1111         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1112                 return (__force __be32)ipv6_addr_hash(
1113                         &flow->addrs.v6addrs.dst);
1114         default:
1115                 return 0;
1116         }
1117 }
1118 EXPORT_SYMBOL(flow_get_u32_dst);
1119
1120 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1121 {
1122         int addr_diff, i;
1123
1124         switch (keys->control.addr_type) {
1125         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1126                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1127                             (__force u32)keys->addrs.v4addrs.src;
1128                 if ((addr_diff < 0) ||
1129                     (addr_diff == 0 &&
1130                      ((__force u16)keys->ports.dst <
1131                       (__force u16)keys->ports.src))) {
1132                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1133                         swap(keys->ports.src, keys->ports.dst);
1134                 }
1135                 break;
1136         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1137                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1138                                    &keys->addrs.v6addrs.src,
1139                                    sizeof(keys->addrs.v6addrs.dst));
1140                 if ((addr_diff < 0) ||
1141                     (addr_diff == 0 &&
1142                      ((__force u16)keys->ports.dst <
1143                       (__force u16)keys->ports.src))) {
1144                         for (i = 0; i < 4; i++)
1145                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1146                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1147                         swap(keys->ports.src, keys->ports.dst);
1148                 }
1149                 break;
1150         }
1151 }
1152
1153 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1154 {
1155         u32 hash;
1156
1157         __flow_hash_consistentify(keys);
1158
1159         hash = __flow_hash_words(flow_keys_hash_start(keys),
1160                                  flow_keys_hash_length(keys), keyval);
1161         if (!hash)
1162                 hash = 1;
1163
1164         return hash;
1165 }
1166
1167 u32 flow_hash_from_keys(struct flow_keys *keys)
1168 {
1169         __flow_hash_secret_init();
1170         return __flow_hash_from_keys(keys, hashrnd);
1171 }
1172 EXPORT_SYMBOL(flow_hash_from_keys);
1173
1174 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1175                                   struct flow_keys *keys, u32 keyval)
1176 {
1177         skb_flow_dissect_flow_keys(skb, keys,
1178                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1179
1180         return __flow_hash_from_keys(keys, keyval);
1181 }
1182
1183 struct _flow_keys_digest_data {
1184         __be16  n_proto;
1185         u8      ip_proto;
1186         u8      padding;
1187         __be32  ports;
1188         __be32  src;
1189         __be32  dst;
1190 };
1191
1192 void make_flow_keys_digest(struct flow_keys_digest *digest,
1193                            const struct flow_keys *flow)
1194 {
1195         struct _flow_keys_digest_data *data =
1196             (struct _flow_keys_digest_data *)digest;
1197
1198         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1199
1200         memset(digest, 0, sizeof(*digest));
1201
1202         data->n_proto = flow->basic.n_proto;
1203         data->ip_proto = flow->basic.ip_proto;
1204         data->ports = flow->ports.ports;
1205         data->src = flow->addrs.v4addrs.src;
1206         data->dst = flow->addrs.v4addrs.dst;
1207 }
1208 EXPORT_SYMBOL(make_flow_keys_digest);
1209
1210 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1211
1212 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1213 {
1214         struct flow_keys keys;
1215
1216         __flow_hash_secret_init();
1217
1218         memset(&keys, 0, sizeof(keys));
1219         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1220                            NULL, 0, 0, 0,
1221                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1222
1223         return __flow_hash_from_keys(&keys, hashrnd);
1224 }
1225 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1226
1227 /**
1228  * __skb_get_hash: calculate a flow hash
1229  * @skb: sk_buff to calculate flow hash from
1230  *
1231  * This function calculates a flow hash based on src/dst addresses
1232  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1233  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1234  * if hash is a canonical 4-tuple hash over transport ports.
1235  */
1236 void __skb_get_hash(struct sk_buff *skb)
1237 {
1238         struct flow_keys keys;
1239         u32 hash;
1240
1241         __flow_hash_secret_init();
1242
1243         hash = ___skb_get_hash(skb, &keys, hashrnd);
1244
1245         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1246 }
1247 EXPORT_SYMBOL(__skb_get_hash);
1248
1249 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1250 {
1251         struct flow_keys keys;
1252
1253         return ___skb_get_hash(skb, &keys, perturb);
1254 }
1255 EXPORT_SYMBOL(skb_get_hash_perturb);
1256
1257 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1258                    const struct flow_keys_basic *keys, int hlen)
1259 {
1260         u32 poff = keys->control.thoff;
1261
1262         /* skip L4 headers for fragments after the first */
1263         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1264             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1265                 return poff;
1266
1267         switch (keys->basic.ip_proto) {
1268         case IPPROTO_TCP: {
1269                 /* access doff as u8 to avoid unaligned access */
1270                 const u8 *doff;
1271                 u8 _doff;
1272
1273                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1274                                             data, hlen, &_doff);
1275                 if (!doff)
1276                         return poff;
1277
1278                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1279                 break;
1280         }
1281         case IPPROTO_UDP:
1282         case IPPROTO_UDPLITE:
1283                 poff += sizeof(struct udphdr);
1284                 break;
1285         /* For the rest, we do not really care about header
1286          * extensions at this point for now.
1287          */
1288         case IPPROTO_ICMP:
1289                 poff += sizeof(struct icmphdr);
1290                 break;
1291         case IPPROTO_ICMPV6:
1292                 poff += sizeof(struct icmp6hdr);
1293                 break;
1294         case IPPROTO_IGMP:
1295                 poff += sizeof(struct igmphdr);
1296                 break;
1297         case IPPROTO_DCCP:
1298                 poff += sizeof(struct dccp_hdr);
1299                 break;
1300         case IPPROTO_SCTP:
1301                 poff += sizeof(struct sctphdr);
1302                 break;
1303         }
1304
1305         return poff;
1306 }
1307
1308 /**
1309  * skb_get_poff - get the offset to the payload
1310  * @skb: sk_buff to get the payload offset from
1311  *
1312  * The function will get the offset to the payload as far as it could
1313  * be dissected.  The main user is currently BPF, so that we can dynamically
1314  * truncate packets without needing to push actual payload to the user
1315  * space and can analyze headers only, instead.
1316  */
1317 u32 skb_get_poff(const struct sk_buff *skb)
1318 {
1319         struct flow_keys_basic keys;
1320
1321         if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
1322                 return 0;
1323
1324         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1325 }
1326
1327 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1328 {
1329         memset(keys, 0, sizeof(*keys));
1330
1331         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1332             sizeof(keys->addrs.v6addrs.src));
1333         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1334             sizeof(keys->addrs.v6addrs.dst));
1335         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1336         keys->ports.src = fl6->fl6_sport;
1337         keys->ports.dst = fl6->fl6_dport;
1338         keys->keyid.keyid = fl6->fl6_gre_key;
1339         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1340         keys->basic.ip_proto = fl6->flowi6_proto;
1341
1342         return flow_hash_from_keys(keys);
1343 }
1344 EXPORT_SYMBOL(__get_hash_from_flowi6);
1345
1346 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1347         {
1348                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1349                 .offset = offsetof(struct flow_keys, control),
1350         },
1351         {
1352                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1353                 .offset = offsetof(struct flow_keys, basic),
1354         },
1355         {
1356                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1357                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1358         },
1359         {
1360                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1361                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1362         },
1363         {
1364                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1365                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1366         },
1367         {
1368                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1369                 .offset = offsetof(struct flow_keys, ports),
1370         },
1371         {
1372                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1373                 .offset = offsetof(struct flow_keys, vlan),
1374         },
1375         {
1376                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1377                 .offset = offsetof(struct flow_keys, tags),
1378         },
1379         {
1380                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1381                 .offset = offsetof(struct flow_keys, keyid),
1382         },
1383 };
1384
1385 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1386         {
1387                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1388                 .offset = offsetof(struct flow_keys, control),
1389         },
1390         {
1391                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1392                 .offset = offsetof(struct flow_keys, basic),
1393         },
1394         {
1395                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1396                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1397         },
1398         {
1399                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1400                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1401         },
1402         {
1403                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1404                 .offset = offsetof(struct flow_keys, ports),
1405         },
1406 };
1407
1408 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1409         {
1410                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1411                 .offset = offsetof(struct flow_keys, control),
1412         },
1413         {
1414                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1415                 .offset = offsetof(struct flow_keys, basic),
1416         },
1417 };
1418
1419 struct flow_dissector flow_keys_dissector __read_mostly;
1420 EXPORT_SYMBOL(flow_keys_dissector);
1421
1422 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1423 EXPORT_SYMBOL(flow_keys_basic_dissector);
1424
1425 static int __init init_default_flow_dissectors(void)
1426 {
1427         skb_flow_dissector_init(&flow_keys_dissector,
1428                                 flow_keys_dissector_keys,
1429                                 ARRAY_SIZE(flow_keys_dissector_keys));
1430         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1431                                 flow_keys_dissector_symmetric_keys,
1432                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1433         skb_flow_dissector_init(&flow_keys_basic_dissector,
1434                                 flow_keys_basic_dissector_keys,
1435                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1436         return 0;
1437 }
1438
1439 core_initcall(init_default_flow_dissectors);