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
  28 static void dissector_set_key(struct flow_dissector *flow_dissector,
  29                               enum flow_dissector_key_id key_id)
  30 {
  31         flow_dissector->used_keys |= (1 << key_id);
  32 }
  33
  34 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  35                              const struct flow_dissector_key *key,
  36                              unsigned int key_count)
  37 {
  38         unsigned int i;
  39
  40         memset(flow_dissector, 0, sizeof(*flow_dissector));
  41
  42         for (i = 0; i < key_count; i++, key++) {
  43                 /* User should make sure that every key target offset is withing
  44                  * boundaries of unsigned short.
  45                  */
  46                 BUG_ON(key->offset > USHRT_MAX);
  47                 BUG_ON(dissector_uses_key(flow_dissector,
  48                                           key->key_id));
  49
  50                 dissector_set_key(flow_dissector, key->key_id);
  51                 flow_dissector->offset[key->key_id] = key->offset;
  52         }
  53
  54         /* Ensure that the dissector always includes control and basic key.
  55          * That way we are able to avoid handling lack of these in fast path.
  56          */
  57         BUG_ON(!dissector_uses_key(flow_dissector,
  58                                    FLOW_DISSECTOR_KEY_CONTROL));
  59         BUG_ON(!dissector_uses_key(flow_dissector,
  60                                    FLOW_DISSECTOR_KEY_BASIC));
  61 }
  62 EXPORT_SYMBOL(skb_flow_dissector_init);
  63
  64 /**
  65  * skb_flow_get_be16 - extract be16 entity
  66  * @skb: sk_buff to extract from
  67  * @poff: offset to extract at
  68  * @data: raw buffer pointer to the packet
  69  * @hlen: packet header length
  70  *
  71  * The function will try to retrieve a be32 entity at
  72  * offset poff
  73  */
  74 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
  75                                 void *data, int hlen)
  76 {
  77         __be16 *u, _u;
  78
  79         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
  80         if (u)
  81                 return *u;
  82
  83         return 0;
  84 }
  85
  86 /**
  87  * __skb_flow_get_ports - extract the upper layer ports and return them
  88  * @skb: sk_buff to extract the ports from
  89  * @thoff: transport header offset
  90  * @ip_proto: protocol for which to get port offset
  91  * @data: raw buffer pointer to the packet, if NULL use skb->data
  92  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  93  *
  94  * The function will try to retrieve the ports at offset thoff + poff where poff
  95  * is the protocol port offset returned from proto_ports_offset
  96  */
  97 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  98                             void *data, int hlen)
  99 {
 100         int poff = proto_ports_offset(ip_proto);
 101
 102         if (!data) {
 103                 data = skb->data;
 104                 hlen = skb_headlen(skb);
 105         }
 106
 107         if (poff >= 0) {
 108                 __be32 *ports, _ports;
 109
 110                 ports = __skb_header_pointer(skb, thoff + poff,
 111                                              sizeof(_ports), data, hlen, &_ports);
 112                 if (ports)
 113                         return *ports;
 114         }
 115
 116         return 0;
 117 }
 118 EXPORT_SYMBOL(__skb_flow_get_ports);
 119
 120 static void
 121 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
 122                                    struct flow_dissector *flow_dissector,
 123                                    void *target_container)
 124 {
 125         struct flow_dissector_key_control *ctrl;
 126
 127         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
 128                 return;
 129
 130         ctrl = skb_flow_dissector_target(flow_dissector,
 131                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
 132                                          target_container);
 133         ctrl->addr_type = type;
 134 }
 135
 136 static void
 137 __skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
 138                                struct flow_dissector *flow_dissector,
 139                                void *target_container)
 140 {
 141         struct ip_tunnel_info *info;
 142         struct ip_tunnel_key *key;
 143
 144         /* A quick check to see if there might be something to do. */
 145         if (!dissector_uses_key(flow_dissector,
 146                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
 147             !dissector_uses_key(flow_dissector,
 148                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
 149             !dissector_uses_key(flow_dissector,
 150                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
 151             !dissector_uses_key(flow_dissector,
 152                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
 153             !dissector_uses_key(flow_dissector,
 154                                 FLOW_DISSECTOR_KEY_ENC_PORTS))
 155                 return;
 156
 157         info = skb_tunnel_info(skb);
 158         if (!info)
 159                 return;
 160
 161         key = &info->key;
 162
 163         switch (ip_tunnel_info_af(info)) {
 164         case AF_INET:
 165                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 166                                                    flow_dissector,
 167                                                    target_container);
 168                 if (dissector_uses_key(flow_dissector,
 169                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 170                         struct flow_dissector_key_ipv4_addrs *ipv4;
 171
 172                         ipv4 = skb_flow_dissector_target(flow_dissector,
 173                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 174                                                          target_container);
 175                         ipv4->src = key->u.ipv4.src;
 176                         ipv4->dst = key->u.ipv4.dst;
 177                 }
 178                 break;
 179         case AF_INET6:
 180                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 181                                                    flow_dissector,
 182                                                    target_container);
 183                 if (dissector_uses_key(flow_dissector,
 184                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 185                         struct flow_dissector_key_ipv6_addrs *ipv6;
 186
 187                         ipv6 = skb_flow_dissector_target(flow_dissector,
 188                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 189                                                          target_container);
 190                         ipv6->src = key->u.ipv6.src;
 191                         ipv6->dst = key->u.ipv6.dst;
 192                 }
 193                 break;
 194         }
 195
 196         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 197                 struct flow_dissector_key_keyid *keyid;
 198
 199                 keyid = skb_flow_dissector_target(flow_dissector,
 200                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
 201                                                   target_container);
 202                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
 203         }
 204
 205         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 206                 struct flow_dissector_key_ports *tp;
 207
 208                 tp = skb_flow_dissector_target(flow_dissector,
 209                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
 210                                                target_container);
 211                 tp->src = key->tp_src;
 212                 tp->dst = key->tp_dst;
 213         }
 214 }
 215
 216 static enum flow_dissect_ret
 217 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 218                         struct flow_dissector *flow_dissector,
 219                         void *target_container, void *data, int nhoff, int hlen)
 220 {
 221         struct flow_dissector_key_keyid *key_keyid;
 222         struct mpls_label *hdr, _hdr[2];
 223         u32 entry, label;
 224
 225         if (!dissector_uses_key(flow_dissector,
 226                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 227             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 228                 return FLOW_DISSECT_RET_OUT_GOOD;
 229
 230         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 231                                    hlen, &_hdr);
 232         if (!hdr)
 233                 return FLOW_DISSECT_RET_OUT_BAD;
 234
 235         entry = ntohl(hdr[0].entry);
 236         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 237
 238         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 239                 struct flow_dissector_key_mpls *key_mpls;
 240
 241                 key_mpls = skb_flow_dissector_target(flow_dissector,
 242                                                      FLOW_DISSECTOR_KEY_MPLS,
 243                                                      target_container);
 244                 key_mpls->mpls_label = label;
 245                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
 246                                         >> MPLS_LS_TTL_SHIFT;
 247                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
 248                                         >> MPLS_LS_TC_SHIFT;
 249                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
 250                                         >> MPLS_LS_S_SHIFT;
 251         }
 252
 253         if (label == MPLS_LABEL_ENTROPY) {
 254                 key_keyid = skb_flow_dissector_target(flow_dissector,
 255                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 256                                                       target_container);
 257                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
 258         }
 259         return FLOW_DISSECT_RET_OUT_GOOD;
 260 }
 261
 262 static enum flow_dissect_ret
 263 __skb_flow_dissect_arp(const struct sk_buff *skb,
 264                        struct flow_dissector *flow_dissector,
 265                        void *target_container, void *data, int nhoff, int hlen)
 266 {
 267         struct flow_dissector_key_arp *key_arp;
 268         struct {
 269                 unsigned char ar_sha[ETH_ALEN];
 270                 unsigned char ar_sip[4];
 271                 unsigned char ar_tha[ETH_ALEN];
 272                 unsigned char ar_tip[4];
 273         } *arp_eth, _arp_eth;
 274         const struct arphdr *arp;
 275         struct arphdr _arp;
 276
 277         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 278                 return FLOW_DISSECT_RET_OUT_GOOD;
 279
 280         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 281                                    hlen, &_arp);
 282         if (!arp)
 283                 return FLOW_DISSECT_RET_OUT_BAD;
 284
 285         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 286             arp->ar_pro != htons(ETH_P_IP) ||
 287             arp->ar_hln != ETH_ALEN ||
 288             arp->ar_pln != 4 ||
 289             (arp->ar_op != htons(ARPOP_REPLY) &&
 290              arp->ar_op != htons(ARPOP_REQUEST)))
 291                 return FLOW_DISSECT_RET_OUT_BAD;
 292
 293         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 294                                        sizeof(_arp_eth), data,
 295                                        hlen, &_arp_eth);
 296         if (!arp_eth)
 297                 return FLOW_DISSECT_RET_OUT_BAD;
 298
 299         key_arp = skb_flow_dissector_target(flow_dissector,
 300                                             FLOW_DISSECTOR_KEY_ARP,
 301                                             target_container);
 302
 303         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 304         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 305
 306         /* Only store the lower byte of the opcode;
 307          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 308          */
 309         key_arp->op = ntohs(arp->ar_op) & 0xff;
 310
 311         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 312         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 313
 314         return FLOW_DISSECT_RET_OUT_GOOD;
 315 }
 316
 317 static enum flow_dissect_ret
 318 __skb_flow_dissect_gre(const struct sk_buff *skb,
 319                        struct flow_dissector_key_control *key_control,
 320                        struct flow_dissector *flow_dissector,
 321                        void *target_container, void *data,
 322                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 323                        unsigned int flags)
 324 {
 325         struct flow_dissector_key_keyid *key_keyid;
 326         struct gre_base_hdr *hdr, _hdr;
 327         int offset = 0;
 328         u16 gre_ver;
 329
 330         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 331                                    data, *p_hlen, &_hdr);
 332         if (!hdr)
 333                 return FLOW_DISSECT_RET_OUT_BAD;
 334
 335         /* Only look inside GRE without routing */
 336         if (hdr->flags & GRE_ROUTING)
 337                 return FLOW_DISSECT_RET_OUT_GOOD;
 338
 339         /* Only look inside GRE for version 0 and 1 */
 340         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 341         if (gre_ver > 1)
 342                 return FLOW_DISSECT_RET_OUT_GOOD;
 343
 344         *p_proto = hdr->protocol;
 345         if (gre_ver) {
 346                 /* Version1 must be PPTP, and check the flags */
 347                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 348                         return FLOW_DISSECT_RET_OUT_GOOD;
 349         }
 350
 351         offset += sizeof(struct gre_base_hdr);
 352
 353         if (hdr->flags & GRE_CSUM)
 354                 offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
 355                           sizeof(((struct gre_full_hdr *) 0)->reserved1);
 356
 357         if (hdr->flags & GRE_KEY) {
 358                 const __be32 *keyid;
 359                 __be32 _keyid;
 360
 361                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 362                                              sizeof(_keyid),
 363                                              data, *p_hlen, &_keyid);
 364                 if (!keyid)
 365                         return FLOW_DISSECT_RET_OUT_BAD;
 366
 367                 if (dissector_uses_key(flow_dissector,
 368                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 369                         key_keyid = skb_flow_dissector_target(flow_dissector,
 370                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 371                                                               target_container);
 372                         if (gre_ver == 0)
 373                                 key_keyid->keyid = *keyid;
 374                         else
 375                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 376                 }
 377                 offset += sizeof(((struct gre_full_hdr *) 0)->key);
 378         }
 379
 380         if (hdr->flags & GRE_SEQ)
 381                 offset += sizeof(((struct pptp_gre_header *) 0)->seq);
 382
 383         if (gre_ver == 0) {
 384                 if (*p_proto == htons(ETH_P_TEB)) {
 385                         const struct ethhdr *eth;
 386                         struct ethhdr _eth;
 387
 388                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 389                                                    sizeof(_eth),
 390                                                    data, *p_hlen, &_eth);
 391                         if (!eth)
 392                                 return FLOW_DISSECT_RET_OUT_BAD;
 393                         *p_proto = eth->h_proto;
 394                         offset += sizeof(*eth);
 395
 396                         /* Cap headers that we access via pointers at the
 397                          * end of the Ethernet header as our maximum alignment
 398                          * at that point is only 2 bytes.
 399                          */
 400                         if (NET_IP_ALIGN)
 401                                 *p_hlen = *p_nhoff + offset;
 402                 }
 403         } else { /* version 1, must be PPTP */
 404                 u8 _ppp_hdr[PPP_HDRLEN];
 405                 u8 *ppp_hdr;
 406
 407                 if (hdr->flags & GRE_ACK)
 408                         offset += sizeof(((struct pptp_gre_header *) 0)->ack);
 409
 410                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 411                                                sizeof(_ppp_hdr),
 412                                                data, *p_hlen, _ppp_hdr);
 413                 if (!ppp_hdr)
 414                         return FLOW_DISSECT_RET_OUT_BAD;
 415
 416                 switch (PPP_PROTOCOL(ppp_hdr)) {
 417                 case PPP_IP:
 418                         *p_proto = htons(ETH_P_IP);
 419                         break;
 420                 case PPP_IPV6:
 421                         *p_proto = htons(ETH_P_IPV6);
 422                         break;
 423                 default:
 424                         /* Could probably catch some more like MPLS */
 425                         break;
 426                 }
 427
 428                 offset += PPP_HDRLEN;
 429         }
 430
 431         *p_nhoff += offset;
 432         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 433         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 434                 return FLOW_DISSECT_RET_OUT_GOOD;
 435
 436         return FLOW_DISSECT_RET_PROTO_AGAIN;
 437 }
 438
 439 static void
 440 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 441                        struct flow_dissector *flow_dissector,
 442                        void *target_container, void *data, int thoff, int hlen)
 443 {
 444         struct flow_dissector_key_tcp *key_tcp;
 445         struct tcphdr *th, _th;
 446
 447         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 448                 return;
 449
 450         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 451         if (!th)
 452                 return;
 453
 454         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 455                 return;
 456
 457         key_tcp = skb_flow_dissector_target(flow_dissector,
 458                                             FLOW_DISSECTOR_KEY_TCP,
 459                                             target_container);
 460         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 461 }
 462
 463 static void
 464 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 465                         struct flow_dissector *flow_dissector,
 466                         void *target_container, void *data, const struct iphdr *iph)
 467 {
 468         struct flow_dissector_key_ip *key_ip;
 469
 470         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 471                 return;
 472
 473         key_ip = skb_flow_dissector_target(flow_dissector,
 474                                            FLOW_DISSECTOR_KEY_IP,
 475                                            target_container);
 476         key_ip->tos = iph->tos;
 477         key_ip->ttl = iph->ttl;
 478 }
 479
 480 static void
 481 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 482                         struct flow_dissector *flow_dissector,
 483                         void *target_container, void *data, const struct ipv6hdr *iph)
 484 {
 485         struct flow_dissector_key_ip *key_ip;
 486
 487         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 488                 return;
 489
 490         key_ip = skb_flow_dissector_target(flow_dissector,
 491                                            FLOW_DISSECTOR_KEY_IP,
 492                                            target_container);
 493         key_ip->tos = ipv6_get_dsfield(iph);
 494         key_ip->ttl = iph->hop_limit;
 495 }
 496
 497 /* Maximum number of protocol headers that can be parsed in
 498  * __skb_flow_dissect
 499  */
 500 #define MAX_FLOW_DISSECT_HDRS   15
 501
 502 static bool skb_flow_dissect_allowed(int *num_hdrs)
 503 {
 504         ++*num_hdrs;
 505
 506         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 507 }
 508
 509 /**
 510  * __skb_flow_dissect - extract the flow_keys struct and return it
 511  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 512  * @flow_dissector: list of keys to dissect
 513  * @target_container: target structure to put dissected values into
 514  * @data: raw buffer pointer to the packet, if NULL use skb->data
 515  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 516  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 517  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 518  *
 519  * The function will try to retrieve individual keys into target specified
 520  * by flow_dissector from either the skbuff or a raw buffer specified by the
 521  * rest parameters.
 522  *
 523  * Caller must take care of zeroing target container memory.
 524  */
 525 bool __skb_flow_dissect(const struct sk_buff *skb,
 526                         struct flow_dissector *flow_dissector,
 527                         void *target_container,
 528                         void *data, __be16 proto, int nhoff, int hlen,
 529                         unsigned int flags)
 530 {
 531         struct flow_dissector_key_control *key_control;
 532         struct flow_dissector_key_basic *key_basic;
 533         struct flow_dissector_key_addrs *key_addrs;
 534         struct flow_dissector_key_ports *key_ports;
 535         struct flow_dissector_key_icmp *key_icmp;
 536         struct flow_dissector_key_tags *key_tags;
 537         struct flow_dissector_key_vlan *key_vlan;
 538         enum flow_dissect_ret fdret;
 539         bool skip_vlan = false;
 540         int num_hdrs = 0;
 541         u8 ip_proto = 0;
 542         bool ret;
 543
 544         if (!data) {
 545                 data = skb->data;
 546                 proto = skb_vlan_tag_present(skb) ?
 547                          skb->vlan_proto : skb->protocol;
 548                 nhoff = skb_network_offset(skb);
 549                 hlen = skb_headlen(skb);
 550 #if IS_ENABLED(CONFIG_NET_DSA)
 551                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
 552                              proto == htons(ETH_P_XDSA))) {
 553                         const struct dsa_device_ops *ops;
 554                         int offset = 0;
 555
 556                         ops = skb->dev->dsa_ptr->tag_ops;
 557                         if (ops->flow_dissect &&
 558                             !ops->flow_dissect(skb, &proto, &offset)) {
 559                                 hlen -= offset;
 560                                 nhoff += offset;
 561                         }
 562                 }
 563 #endif
 564         }
 565
 566         /* It is ensured by skb_flow_dissector_init() that control key will
 567          * be always present.
 568          */
 569         key_control = skb_flow_dissector_target(flow_dissector,
 570                                                 FLOW_DISSECTOR_KEY_CONTROL,
 571                                                 target_container);
 572
 573         /* It is ensured by skb_flow_dissector_init() that basic key will
 574          * be always present.
 575          */
 576         key_basic = skb_flow_dissector_target(flow_dissector,
 577                                               FLOW_DISSECTOR_KEY_BASIC,
 578                                               target_container);
 579
 580         __skb_flow_dissect_tunnel_info(skb, flow_dissector,
 581                                        target_container);
 582
 583         if (dissector_uses_key(flow_dissector,
 584                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 585                 struct ethhdr *eth = eth_hdr(skb);
 586                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 587
 588                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 589                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 590                                                           target_container);
 591                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 592         }
 593
 594 proto_again:
 595         fdret = FLOW_DISSECT_RET_CONTINUE;
 596
 597         switch (proto) {
 598         case htons(ETH_P_IP): {
 599                 const struct iphdr *iph;
 600                 struct iphdr _iph;
 601
 602                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 603                 if (!iph || iph->ihl < 5) {
 604                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 605                         break;
 606                 }
 607
 608                 nhoff += iph->ihl * 4;
 609
 610                 ip_proto = iph->protocol;
 611
 612                 if (dissector_uses_key(flow_dissector,
 613                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 614                         key_addrs = skb_flow_dissector_target(flow_dissector,
 615                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 616                                                               target_container);
 617
 618                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 619                                sizeof(key_addrs->v4addrs));
 620                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 621                 }
 622
 623                 if (ip_is_fragment(iph)) {
 624                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 625
 626                         if (iph->frag_off & htons(IP_OFFSET)) {
 627                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 628                                 break;
 629                         } else {
 630                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 631                                 if (!(flags &
 632                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
 633                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 634                                         break;
 635                                 }
 636                         }
 637                 }
 638
 639                 __skb_flow_dissect_ipv4(skb, flow_dissector,
 640                                         target_container, data, iph);
 641
 642                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
 643                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 644                         break;
 645                 }
 646
 647                 break;
 648         }
 649         case htons(ETH_P_IPV6): {
 650                 const struct ipv6hdr *iph;
 651                 struct ipv6hdr _iph;
 652
 653                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 654                 if (!iph) {
 655                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 656                         break;
 657                 }
 658
 659                 ip_proto = iph->nexthdr;
 660                 nhoff += sizeof(struct ipv6hdr);
 661
 662                 if (dissector_uses_key(flow_dissector,
 663                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 664                         key_addrs = skb_flow_dissector_target(flow_dissector,
 665                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 666                                                               target_container);
 667
 668                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 669                                sizeof(key_addrs->v6addrs));
 670                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 671                 }
 672
 673                 if ((dissector_uses_key(flow_dissector,
 674                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 675                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 676                     ip6_flowlabel(iph)) {
 677                         __be32 flow_label = ip6_flowlabel(iph);
 678
 679                         if (dissector_uses_key(flow_dissector,
 680                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 681                                 key_tags = skb_flow_dissector_target(flow_dissector,
 682                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 683                                                                      target_container);
 684                                 key_tags->flow_label = ntohl(flow_label);
 685                         }
 686                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
 687                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 688                                 break;
 689                         }
 690                 }
 691
 692                 __skb_flow_dissect_ipv6(skb, flow_dissector,
 693                                         target_container, data, iph);
 694
 695                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 696                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 697
 698                 break;
 699         }
 700         case htons(ETH_P_8021AD):
 701         case htons(ETH_P_8021Q): {
 702                 const struct vlan_hdr *vlan;
 703                 struct vlan_hdr _vlan;
 704                 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
 705
 706                 if (vlan_tag_present)
 707                         proto = skb->protocol;
 708
 709                 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
 710                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 711                                                     data, hlen, &_vlan);
 712                         if (!vlan) {
 713                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 714                                 break;
 715                         }
 716
 717                         proto = vlan->h_vlan_encapsulated_proto;
 718                         nhoff += sizeof(*vlan);
 719                         if (skip_vlan) {
 720                                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 721                                 break;
 722                         }
 723                 }
 724
 725                 skip_vlan = true;
 726                 if (dissector_uses_key(flow_dissector,
 727                                        FLOW_DISSECTOR_KEY_VLAN)) {
 728                         key_vlan = skb_flow_dissector_target(flow_dissector,
 729                                                              FLOW_DISSECTOR_KEY_VLAN,
 730                                                              target_container);
 731
 732                         if (vlan_tag_present) {
 733                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 734                                 key_vlan->vlan_priority =
 735                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 736                         } else {
 737                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 738                                         VLAN_VID_MASK;
 739                                 key_vlan->vlan_priority =
 740                                         (ntohs(vlan->h_vlan_TCI) &
 741                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 742                         }
 743                 }
 744
 745                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 746                 break;
 747         }
 748         case htons(ETH_P_PPP_SES): {
 749                 struct {
 750                         struct pppoe_hdr hdr;
 751                         __be16 proto;
 752                 } *hdr, _hdr;
 753                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 754                 if (!hdr) {
 755                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 756                         break;
 757                 }
 758
 759                 proto = hdr->proto;
 760                 nhoff += PPPOE_SES_HLEN;
 761                 switch (proto) {
 762                 case htons(PPP_IP):
 763                         proto = htons(ETH_P_IP);
 764                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 765                         break;
 766                 case htons(PPP_IPV6):
 767                         proto = htons(ETH_P_IPV6);
 768                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 769                         break;
 770                 default:
 771                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 772                         break;
 773                 }
 774                 break;
 775         }
 776         case htons(ETH_P_TIPC): {
 777                 struct tipc_basic_hdr *hdr, _hdr;
 778
 779                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
 780                                            data, hlen, &_hdr);
 781                 if (!hdr) {
 782                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 783                         break;
 784                 }
 785
 786                 if (dissector_uses_key(flow_dissector,
 787                                        FLOW_DISSECTOR_KEY_TIPC)) {
 788                         key_addrs = skb_flow_dissector_target(flow_dissector,
 789                                                               FLOW_DISSECTOR_KEY_TIPC,
 790                                                               target_container);
 791                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
 792                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
 793                 }
 794                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 795                 break;
 796         }
 797
 798         case htons(ETH_P_MPLS_UC):
 799         case htons(ETH_P_MPLS_MC):
 800                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
 801                                                 target_container, data,
 802                                                 nhoff, hlen);
 803                 break;
 804         case htons(ETH_P_FCOE):
 805                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
 806                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 807                         break;
 808                 }
 809
 810                 nhoff += FCOE_HEADER_LEN;
 811                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 812                 break;
 813
 814         case htons(ETH_P_ARP):
 815         case htons(ETH_P_RARP):
 816                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
 817                                                target_container, data,
 818                                                nhoff, hlen);
 819                 break;
 820
 821         default:
 822                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 823                 break;
 824         }
 825
 826         /* Process result of proto processing */
 827         switch (fdret) {
 828         case FLOW_DISSECT_RET_OUT_GOOD:
 829                 goto out_good;
 830         case FLOW_DISSECT_RET_PROTO_AGAIN:
 831                 if (skb_flow_dissect_allowed(&num_hdrs))
 832                         goto proto_again;
 833                 goto out_good;
 834         case FLOW_DISSECT_RET_CONTINUE:
 835         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 836                 break;
 837         case FLOW_DISSECT_RET_OUT_BAD:
 838         default:
 839                 goto out_bad;
 840         }
 841
 842 ip_proto_again:
 843         fdret = FLOW_DISSECT_RET_CONTINUE;
 844
 845         switch (ip_proto) {
 846         case IPPROTO_GRE:
 847                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
 848                                                target_container, data,
 849                                                &proto, &nhoff, &hlen, flags);
 850                 break;
 851
 852         case NEXTHDR_HOP:
 853         case NEXTHDR_ROUTING:
 854         case NEXTHDR_DEST: {
 855                 u8 _opthdr[2], *opthdr;
 856
 857                 if (proto != htons(ETH_P_IPV6))
 858                         break;
 859
 860                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 861                                               data, hlen, &_opthdr);
 862                 if (!opthdr) {
 863                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 864                         break;
 865                 }
 866
 867                 ip_proto = opthdr[0];
 868                 nhoff += (opthdr[1] + 1) << 3;
 869
 870                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 871                 break;
 872         }
 873         case NEXTHDR_FRAGMENT: {
 874                 struct frag_hdr _fh, *fh;
 875
 876                 if (proto != htons(ETH_P_IPV6))
 877                         break;
 878
 879                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 880                                           data, hlen, &_fh);
 881
 882                 if (!fh) {
 883                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 884                         break;
 885                 }
 886
 887                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 888
 889                 nhoff += sizeof(_fh);
 890                 ip_proto = fh->nexthdr;
 891
 892                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 893                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 894                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 895                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 896                                 break;
 897                         }
 898                 }
 899
 900                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 901                 break;
 902         }
 903         case IPPROTO_IPIP:
 904                 proto = htons(ETH_P_IP);
 905
 906                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 907                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 908                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 909                         break;
 910                 }
 911
 912                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 913                 break;
 914
 915         case IPPROTO_IPV6:
 916                 proto = htons(ETH_P_IPV6);
 917
 918                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 919                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 920                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 921                         break;
 922                 }
 923
 924                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 925                 break;
 926
 927
 928         case IPPROTO_MPLS:
 929                 proto = htons(ETH_P_MPLS_UC);
 930                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 931                 break;
 932
 933         case IPPROTO_TCP:
 934                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
 935                                        data, nhoff, hlen);
 936                 break;
 937
 938         default:
 939                 break;
 940         }
 941
 942         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
 943             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
 944                 key_ports = skb_flow_dissector_target(flow_dissector,
 945                                                       FLOW_DISSECTOR_KEY_PORTS,
 946                                                       target_container);
 947                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 948                                                         data, hlen);
 949         }
 950
 951         if (dissector_uses_key(flow_dissector,
 952                                FLOW_DISSECTOR_KEY_ICMP)) {
 953                 key_icmp = skb_flow_dissector_target(flow_dissector,
 954                                                      FLOW_DISSECTOR_KEY_ICMP,
 955                                                      target_container);
 956                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
 957         }
 958
 959         /* Process result of IP proto processing */
 960         switch (fdret) {
 961         case FLOW_DISSECT_RET_PROTO_AGAIN:
 962                 if (skb_flow_dissect_allowed(&num_hdrs))
 963                         goto proto_again;
 964                 break;
 965         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 966                 if (skb_flow_dissect_allowed(&num_hdrs))
 967                         goto ip_proto_again;
 968                 break;
 969         case FLOW_DISSECT_RET_OUT_GOOD:
 970         case FLOW_DISSECT_RET_CONTINUE:
 971                 break;
 972         case FLOW_DISSECT_RET_OUT_BAD:
 973         default:
 974                 goto out_bad;
 975         }
 976
 977 out_good:
 978         ret = true;
 979
 980 out:
 981         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
 982         key_basic->n_proto = proto;
 983         key_basic->ip_proto = ip_proto;
 984
 985         return ret;
 986
 987 out_bad:
 988         ret = false;
 989         goto out;
 990 }
 991 EXPORT_SYMBOL(__skb_flow_dissect);
 992
 993 static siphash_key_t hashrnd __read_mostly;
 994 static __always_inline void __flow_hash_secret_init(void)
 995 {
 996         net_get_random_once(&hashrnd, sizeof(hashrnd));
 997 }
 998
 999 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1000 {
1001         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1002         return &flow->FLOW_KEYS_HASH_START_FIELD;
1003 }
1004
1005 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1006 {
1007         size_t len = offsetof(typeof(*flow), addrs) - FLOW_KEYS_HASH_OFFSET;
1008
1009         switch (flow->control.addr_type) {
1010         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1011                 len += sizeof(flow->addrs.v4addrs);
1012                 break;
1013         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1014                 len += sizeof(flow->addrs.v6addrs);
1015                 break;
1016         case FLOW_DISSECTOR_KEY_TIPC:
1017                 len += sizeof(flow->addrs.tipckey);
1018                 break;
1019         }
1020         return len;
1021 }
1022
1023 __be32 flow_get_u32_src(const struct flow_keys *flow)
1024 {
1025         switch (flow->control.addr_type) {
1026         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1027                 return flow->addrs.v4addrs.src;
1028         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1029                 return (__force __be32)ipv6_addr_hash(
1030                         &flow->addrs.v6addrs.src);
1031         case FLOW_DISSECTOR_KEY_TIPC:
1032                 return flow->addrs.tipckey.key;
1033         default:
1034                 return 0;
1035         }
1036 }
1037 EXPORT_SYMBOL(flow_get_u32_src);
1038
1039 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1040 {
1041         switch (flow->control.addr_type) {
1042         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1043                 return flow->addrs.v4addrs.dst;
1044         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1045                 return (__force __be32)ipv6_addr_hash(
1046                         &flow->addrs.v6addrs.dst);
1047         default:
1048                 return 0;
1049         }
1050 }
1051 EXPORT_SYMBOL(flow_get_u32_dst);
1052
1053 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1054 {
1055         int addr_diff, i;
1056
1057         switch (keys->control.addr_type) {
1058         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1059                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1060                             (__force u32)keys->addrs.v4addrs.src;
1061                 if ((addr_diff < 0) ||
1062                     (addr_diff == 0 &&
1063                      ((__force u16)keys->ports.dst <
1064                       (__force u16)keys->ports.src))) {
1065                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1066                         swap(keys->ports.src, keys->ports.dst);
1067                 }
1068                 break;
1069         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1070                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1071                                    &keys->addrs.v6addrs.src,
1072                                    sizeof(keys->addrs.v6addrs.dst));
1073                 if ((addr_diff < 0) ||
1074                     (addr_diff == 0 &&
1075                      ((__force u16)keys->ports.dst <
1076                       (__force u16)keys->ports.src))) {
1077                         for (i = 0; i < 4; i++)
1078                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1079                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1080                         swap(keys->ports.src, keys->ports.dst);
1081                 }
1082                 break;
1083         }
1084 }
1085
1086 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1087                                         const siphash_key_t *keyval)
1088 {
1089         u32 hash;
1090
1091         __flow_hash_consistentify(keys);
1092
1093         hash = siphash(flow_keys_hash_start(keys),
1094                        flow_keys_hash_length(keys), keyval);
1095         if (!hash)
1096                 hash = 1;
1097
1098         return hash;
1099 }
1100
1101 u32 flow_hash_from_keys(struct flow_keys *keys)
1102 {
1103         __flow_hash_secret_init();
1104         return __flow_hash_from_keys(keys, &hashrnd);
1105 }
1106 EXPORT_SYMBOL(flow_hash_from_keys);
1107
1108 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1109                                   struct flow_keys *keys,
1110                                   const siphash_key_t *keyval)
1111 {
1112         skb_flow_dissect_flow_keys(skb, keys,
1113                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1114
1115         return __flow_hash_from_keys(keys, keyval);
1116 }
1117
1118 struct _flow_keys_digest_data {
1119         __be16  n_proto;
1120         u8      ip_proto;
1121         u8      padding;
1122         __be32  ports;
1123         __be32  src;
1124         __be32  dst;
1125 };
1126
1127 void make_flow_keys_digest(struct flow_keys_digest *digest,
1128                            const struct flow_keys *flow)
1129 {
1130         struct _flow_keys_digest_data *data =
1131             (struct _flow_keys_digest_data *)digest;
1132
1133         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1134
1135         memset(digest, 0, sizeof(*digest));
1136
1137         data->n_proto = flow->basic.n_proto;
1138         data->ip_proto = flow->basic.ip_proto;
1139         data->ports = flow->ports.ports;
1140         data->src = flow->addrs.v4addrs.src;
1141         data->dst = flow->addrs.v4addrs.dst;
1142 }
1143 EXPORT_SYMBOL(make_flow_keys_digest);
1144
1145 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1146
1147 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1148 {
1149         struct flow_keys keys;
1150
1151         __flow_hash_secret_init();
1152
1153         memset(&keys, 0, sizeof(keys));
1154         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1155                            NULL, 0, 0, 0,
1156                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1157
1158         return __flow_hash_from_keys(&keys, &hashrnd);
1159 }
1160 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1161
1162 /**
1163  * __skb_get_hash: calculate a flow hash
1164  * @skb: sk_buff to calculate flow hash from
1165  *
1166  * This function calculates a flow hash based on src/dst addresses
1167  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1168  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1169  * if hash is a canonical 4-tuple hash over transport ports.
1170  */
1171 void __skb_get_hash(struct sk_buff *skb)
1172 {
1173         struct flow_keys keys;
1174         u32 hash;
1175
1176         __flow_hash_secret_init();
1177
1178         hash = ___skb_get_hash(skb, &keys, &hashrnd);
1179
1180         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1181 }
1182 EXPORT_SYMBOL(__skb_get_hash);
1183
1184 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1185                            const siphash_key_t *perturb)
1186 {
1187         struct flow_keys keys;
1188
1189         return ___skb_get_hash(skb, &keys, perturb);
1190 }
1191 EXPORT_SYMBOL(skb_get_hash_perturb);
1192
1193 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1194                    const struct flow_keys *keys, int hlen)
1195 {
1196         u32 poff = keys->control.thoff;
1197
1198         /* skip L4 headers for fragments after the first */
1199         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1200             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1201                 return poff;
1202
1203         switch (keys->basic.ip_proto) {
1204         case IPPROTO_TCP: {
1205                 /* access doff as u8 to avoid unaligned access */
1206                 const u8 *doff;
1207                 u8 _doff;
1208
1209                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1210                                             data, hlen, &_doff);
1211                 if (!doff)
1212                         return poff;
1213
1214                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1215                 break;
1216         }
1217         case IPPROTO_UDP:
1218         case IPPROTO_UDPLITE:
1219                 poff += sizeof(struct udphdr);
1220                 break;
1221         /* For the rest, we do not really care about header
1222          * extensions at this point for now.
1223          */
1224         case IPPROTO_ICMP:
1225                 poff += sizeof(struct icmphdr);
1226                 break;
1227         case IPPROTO_ICMPV6:
1228                 poff += sizeof(struct icmp6hdr);
1229                 break;
1230         case IPPROTO_IGMP:
1231                 poff += sizeof(struct igmphdr);
1232                 break;
1233         case IPPROTO_DCCP:
1234                 poff += sizeof(struct dccp_hdr);
1235                 break;
1236         case IPPROTO_SCTP:
1237                 poff += sizeof(struct sctphdr);
1238                 break;
1239         }
1240
1241         return poff;
1242 }
1243
1244 /**
1245  * skb_get_poff - get the offset to the payload
1246  * @skb: sk_buff to get the payload offset from
1247  *
1248  * The function will get the offset to the payload as far as it could
1249  * be dissected.  The main user is currently BPF, so that we can dynamically
1250  * truncate packets without needing to push actual payload to the user
1251  * space and can analyze headers only, instead.
1252  */
1253 u32 skb_get_poff(const struct sk_buff *skb)
1254 {
1255         struct flow_keys keys;
1256
1257         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
1258                 return 0;
1259
1260         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1261 }
1262
1263 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1264 {
1265         memset(keys, 0, sizeof(*keys));
1266
1267         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1268             sizeof(keys->addrs.v6addrs.src));
1269         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1270             sizeof(keys->addrs.v6addrs.dst));
1271         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1272         keys->ports.src = fl6->fl6_sport;
1273         keys->ports.dst = fl6->fl6_dport;
1274         keys->keyid.keyid = fl6->fl6_gre_key;
1275         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1276         keys->basic.ip_proto = fl6->flowi6_proto;
1277
1278         return flow_hash_from_keys(keys);
1279 }
1280 EXPORT_SYMBOL(__get_hash_from_flowi6);
1281
1282 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
1283 {
1284         memset(keys, 0, sizeof(*keys));
1285
1286         keys->addrs.v4addrs.src = fl4->saddr;
1287         keys->addrs.v4addrs.dst = fl4->daddr;
1288         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1289         keys->ports.src = fl4->fl4_sport;
1290         keys->ports.dst = fl4->fl4_dport;
1291         keys->keyid.keyid = fl4->fl4_gre_key;
1292         keys->basic.ip_proto = fl4->flowi4_proto;
1293
1294         return flow_hash_from_keys(keys);
1295 }
1296 EXPORT_SYMBOL(__get_hash_from_flowi4);
1297
1298 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1299         {
1300                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1301                 .offset = offsetof(struct flow_keys, control),
1302         },
1303         {
1304                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1305                 .offset = offsetof(struct flow_keys, basic),
1306         },
1307         {
1308                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1309                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1310         },
1311         {
1312                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1313                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1314         },
1315         {
1316                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1317                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1318         },
1319         {
1320                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1321                 .offset = offsetof(struct flow_keys, ports),
1322         },
1323         {
1324                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1325                 .offset = offsetof(struct flow_keys, vlan),
1326         },
1327         {
1328                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1329                 .offset = offsetof(struct flow_keys, tags),
1330         },
1331         {
1332                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1333                 .offset = offsetof(struct flow_keys, keyid),
1334         },
1335 };
1336
1337 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1338         {
1339                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1340                 .offset = offsetof(struct flow_keys, control),
1341         },
1342         {
1343                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1344                 .offset = offsetof(struct flow_keys, basic),
1345         },
1346         {
1347                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1348                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1349         },
1350         {
1351                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1352                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1353         },
1354         {
1355                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1356                 .offset = offsetof(struct flow_keys, ports),
1357         },
1358 };
1359
1360 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
1361         {
1362                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1363                 .offset = offsetof(struct flow_keys, control),
1364         },
1365         {
1366                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1367                 .offset = offsetof(struct flow_keys, basic),
1368         },
1369 };
1370
1371 struct flow_dissector flow_keys_dissector __read_mostly;
1372 EXPORT_SYMBOL(flow_keys_dissector);
1373
1374 struct flow_dissector flow_keys_buf_dissector __read_mostly;
1375
1376 static int __init init_default_flow_dissectors(void)
1377 {
1378         skb_flow_dissector_init(&flow_keys_dissector,
1379                                 flow_keys_dissector_keys,
1380                                 ARRAY_SIZE(flow_keys_dissector_keys));
1381         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1382                                 flow_keys_dissector_symmetric_keys,
1383                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1384         skb_flow_dissector_init(&flow_keys_buf_dissector,
1385                                 flow_keys_buf_dissector_keys,
1386                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1387         return 0;
1388 }
1389
1390 core_initcall(init_default_flow_dissectors);