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                         const struct dsa_device_ops *ops;
 553                         int offset;
 554
 555                         ops = skb->dev->dsa_ptr->tag_ops;
 556                         if (ops->flow_dissect &&
 557                             !ops->flow_dissect(skb, &proto, &offset)) {
 558                                 hlen -= offset;
 559                                 nhoff += offset;
 560                         }
 561                 }
 562 #endif
 563         }
 564
 565         /* It is ensured by skb_flow_dissector_init() that control key will
 566          * be always present.
 567          */
 568         key_control = skb_flow_dissector_target(flow_dissector,
 569                                                 FLOW_DISSECTOR_KEY_CONTROL,
 570                                                 target_container);
 571
 572         /* It is ensured by skb_flow_dissector_init() that basic key will
 573          * be always present.
 574          */
 575         key_basic = skb_flow_dissector_target(flow_dissector,
 576                                               FLOW_DISSECTOR_KEY_BASIC,
 577                                               target_container);
 578
 579         __skb_flow_dissect_tunnel_info(skb, flow_dissector,
 580                                        target_container);
 581
 582         if (dissector_uses_key(flow_dissector,
 583                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 584                 struct ethhdr *eth = eth_hdr(skb);
 585                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 586
 587                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 588                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 589                                                           target_container);
 590                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 591         }
 592
 593 proto_again:
 594         fdret = FLOW_DISSECT_RET_CONTINUE;
 595
 596         switch (proto) {
 597         case htons(ETH_P_IP): {
 598                 const struct iphdr *iph;
 599                 struct iphdr _iph;
 600
 601                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 602                 if (!iph || iph->ihl < 5) {
 603                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 604                         break;
 605                 }
 606
 607                 nhoff += iph->ihl * 4;
 608
 609                 ip_proto = iph->protocol;
 610
 611                 if (dissector_uses_key(flow_dissector,
 612                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 613                         key_addrs = skb_flow_dissector_target(flow_dissector,
 614                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 615                                                               target_container);
 616
 617                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 618                                sizeof(key_addrs->v4addrs));
 619                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 620                 }
 621
 622                 if (ip_is_fragment(iph)) {
 623                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 624
 625                         if (iph->frag_off & htons(IP_OFFSET)) {
 626                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 627                                 break;
 628                         } else {
 629                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 630                                 if (!(flags &
 631                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
 632                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 633                                         break;
 634                                 }
 635                         }
 636                 }
 637
 638                 __skb_flow_dissect_ipv4(skb, flow_dissector,
 639                                         target_container, data, iph);
 640
 641                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
 642                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 643                         break;
 644                 }
 645
 646                 break;
 647         }
 648         case htons(ETH_P_IPV6): {
 649                 const struct ipv6hdr *iph;
 650                 struct ipv6hdr _iph;
 651
 652                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 653                 if (!iph) {
 654                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 655                         break;
 656                 }
 657
 658                 ip_proto = iph->nexthdr;
 659                 nhoff += sizeof(struct ipv6hdr);
 660
 661                 if (dissector_uses_key(flow_dissector,
 662                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 663                         key_addrs = skb_flow_dissector_target(flow_dissector,
 664                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 665                                                               target_container);
 666
 667                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 668                                sizeof(key_addrs->v6addrs));
 669                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 670                 }
 671
 672                 if ((dissector_uses_key(flow_dissector,
 673                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 674                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 675                     ip6_flowlabel(iph)) {
 676                         __be32 flow_label = ip6_flowlabel(iph);
 677
 678                         if (dissector_uses_key(flow_dissector,
 679                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 680                                 key_tags = skb_flow_dissector_target(flow_dissector,
 681                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 682                                                                      target_container);
 683                                 key_tags->flow_label = ntohl(flow_label);
 684                         }
 685                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
 686                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 687                                 break;
 688                         }
 689                 }
 690
 691                 __skb_flow_dissect_ipv6(skb, flow_dissector,
 692                                         target_container, data, iph);
 693
 694                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 695                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 696
 697                 break;
 698         }
 699         case htons(ETH_P_8021AD):
 700         case htons(ETH_P_8021Q): {
 701                 const struct vlan_hdr *vlan;
 702                 struct vlan_hdr _vlan;
 703                 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
 704
 705                 if (vlan_tag_present)
 706                         proto = skb->protocol;
 707
 708                 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
 709                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 710                                                     data, hlen, &_vlan);
 711                         if (!vlan) {
 712                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 713                                 break;
 714                         }
 715
 716                         proto = vlan->h_vlan_encapsulated_proto;
 717                         nhoff += sizeof(*vlan);
 718                         if (skip_vlan) {
 719                                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 720                                 break;
 721                         }
 722                 }
 723
 724                 skip_vlan = true;
 725                 if (dissector_uses_key(flow_dissector,
 726                                        FLOW_DISSECTOR_KEY_VLAN)) {
 727                         key_vlan = skb_flow_dissector_target(flow_dissector,
 728                                                              FLOW_DISSECTOR_KEY_VLAN,
 729                                                              target_container);
 730
 731                         if (vlan_tag_present) {
 732                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 733                                 key_vlan->vlan_priority =
 734                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 735                         } else {
 736                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 737                                         VLAN_VID_MASK;
 738                                 key_vlan->vlan_priority =
 739                                         (ntohs(vlan->h_vlan_TCI) &
 740                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 741                         }
 742                 }
 743
 744                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 745                 break;
 746         }
 747         case htons(ETH_P_PPP_SES): {
 748                 struct {
 749                         struct pppoe_hdr hdr;
 750                         __be16 proto;
 751                 } *hdr, _hdr;
 752                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 753                 if (!hdr) {
 754                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 755                         break;
 756                 }
 757
 758                 proto = hdr->proto;
 759                 nhoff += PPPOE_SES_HLEN;
 760                 switch (proto) {
 761                 case htons(PPP_IP):
 762                         proto = htons(ETH_P_IP);
 763                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 764                         break;
 765                 case htons(PPP_IPV6):
 766                         proto = htons(ETH_P_IPV6);
 767                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 768                         break;
 769                 default:
 770                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 771                         break;
 772                 }
 773                 break;
 774         }
 775         case htons(ETH_P_TIPC): {
 776                 struct tipc_basic_hdr *hdr, _hdr;
 777
 778                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
 779                                            data, hlen, &_hdr);
 780                 if (!hdr) {
 781                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 782                         break;
 783                 }
 784
 785                 if (dissector_uses_key(flow_dissector,
 786                                        FLOW_DISSECTOR_KEY_TIPC)) {
 787                         key_addrs = skb_flow_dissector_target(flow_dissector,
 788                                                               FLOW_DISSECTOR_KEY_TIPC,
 789                                                               target_container);
 790                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
 791                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
 792                 }
 793                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 794                 break;
 795         }
 796
 797         case htons(ETH_P_MPLS_UC):
 798         case htons(ETH_P_MPLS_MC):
 799                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
 800                                                 target_container, data,
 801                                                 nhoff, hlen);
 802                 break;
 803         case htons(ETH_P_FCOE):
 804                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
 805                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 806                         break;
 807                 }
 808
 809                 nhoff += FCOE_HEADER_LEN;
 810                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 811                 break;
 812
 813         case htons(ETH_P_ARP):
 814         case htons(ETH_P_RARP):
 815                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
 816                                                target_container, data,
 817                                                nhoff, hlen);
 818                 break;
 819
 820         default:
 821                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 822                 break;
 823         }
 824
 825         /* Process result of proto processing */
 826         switch (fdret) {
 827         case FLOW_DISSECT_RET_OUT_GOOD:
 828                 goto out_good;
 829         case FLOW_DISSECT_RET_PROTO_AGAIN:
 830                 if (skb_flow_dissect_allowed(&num_hdrs))
 831                         goto proto_again;
 832                 goto out_good;
 833         case FLOW_DISSECT_RET_CONTINUE:
 834         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 835                 break;
 836         case FLOW_DISSECT_RET_OUT_BAD:
 837         default:
 838                 goto out_bad;
 839         }
 840
 841 ip_proto_again:
 842         fdret = FLOW_DISSECT_RET_CONTINUE;
 843
 844         switch (ip_proto) {
 845         case IPPROTO_GRE:
 846                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
 847                                                target_container, data,
 848                                                &proto, &nhoff, &hlen, flags);
 849                 break;
 850
 851         case NEXTHDR_HOP:
 852         case NEXTHDR_ROUTING:
 853         case NEXTHDR_DEST: {
 854                 u8 _opthdr[2], *opthdr;
 855
 856                 if (proto != htons(ETH_P_IPV6))
 857                         break;
 858
 859                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 860                                               data, hlen, &_opthdr);
 861                 if (!opthdr) {
 862                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 863                         break;
 864                 }
 865
 866                 ip_proto = opthdr[0];
 867                 nhoff += (opthdr[1] + 1) << 3;
 868
 869                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 870                 break;
 871         }
 872         case NEXTHDR_FRAGMENT: {
 873                 struct frag_hdr _fh, *fh;
 874
 875                 if (proto != htons(ETH_P_IPV6))
 876                         break;
 877
 878                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 879                                           data, hlen, &_fh);
 880
 881                 if (!fh) {
 882                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 883                         break;
 884                 }
 885
 886                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 887
 888                 nhoff += sizeof(_fh);
 889                 ip_proto = fh->nexthdr;
 890
 891                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 892                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 893                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 894                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 895                                 break;
 896                         }
 897                 }
 898
 899                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 900                 break;
 901         }
 902         case IPPROTO_IPIP:
 903                 proto = htons(ETH_P_IP);
 904
 905                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 906                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 907                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 908                         break;
 909                 }
 910
 911                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 912                 break;
 913
 914         case IPPROTO_IPV6:
 915                 proto = htons(ETH_P_IPV6);
 916
 917                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 918                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 919                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 920                         break;
 921                 }
 922
 923                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 924                 break;
 925
 926
 927         case IPPROTO_MPLS:
 928                 proto = htons(ETH_P_MPLS_UC);
 929                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 930                 break;
 931
 932         case IPPROTO_TCP:
 933                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
 934                                        data, nhoff, hlen);
 935                 break;
 936
 937         default:
 938                 break;
 939         }
 940
 941         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
 942             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
 943                 key_ports = skb_flow_dissector_target(flow_dissector,
 944                                                       FLOW_DISSECTOR_KEY_PORTS,
 945                                                       target_container);
 946                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 947                                                         data, hlen);
 948         }
 949
 950         if (dissector_uses_key(flow_dissector,
 951                                FLOW_DISSECTOR_KEY_ICMP)) {
 952                 key_icmp = skb_flow_dissector_target(flow_dissector,
 953                                                      FLOW_DISSECTOR_KEY_ICMP,
 954                                                      target_container);
 955                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
 956         }
 957
 958         /* Process result of IP proto processing */
 959         switch (fdret) {
 960         case FLOW_DISSECT_RET_PROTO_AGAIN:
 961                 if (skb_flow_dissect_allowed(&num_hdrs))
 962                         goto proto_again;
 963                 break;
 964         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 965                 if (skb_flow_dissect_allowed(&num_hdrs))
 966                         goto ip_proto_again;
 967                 break;
 968         case FLOW_DISSECT_RET_OUT_GOOD:
 969         case FLOW_DISSECT_RET_CONTINUE:
 970                 break;
 971         case FLOW_DISSECT_RET_OUT_BAD:
 972         default:
 973                 goto out_bad;
 974         }
 975
 976 out_good:
 977         ret = true;
 978
 979 out:
 980         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
 981         key_basic->n_proto = proto;
 982         key_basic->ip_proto = ip_proto;
 983
 984         return ret;
 985
 986 out_bad:
 987         ret = false;
 988         goto out;
 989 }
 990 EXPORT_SYMBOL(__skb_flow_dissect);
 991
 992 static u32 hashrnd __read_mostly;
 993 static __always_inline void __flow_hash_secret_init(void)
 994 {
 995         net_get_random_once(&hashrnd, sizeof(hashrnd));
 996 }
 997
 998 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 999                                              u32 keyval)
1000 {
1001         return jhash2(words, length, keyval);
1002 }
1003
1004 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1005 {
1006         const void *p = flow;
1007
1008         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1009         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1010 }
1011
1012 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1013 {
1014         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1015         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1016         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1017                      sizeof(*flow) - sizeof(flow->addrs));
1018
1019         switch (flow->control.addr_type) {
1020         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1021                 diff -= sizeof(flow->addrs.v4addrs);
1022                 break;
1023         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1024                 diff -= sizeof(flow->addrs.v6addrs);
1025                 break;
1026         case FLOW_DISSECTOR_KEY_TIPC:
1027                 diff -= sizeof(flow->addrs.tipckey);
1028                 break;
1029         }
1030         return (sizeof(*flow) - diff) / sizeof(u32);
1031 }
1032
1033 __be32 flow_get_u32_src(const struct flow_keys *flow)
1034 {
1035         switch (flow->control.addr_type) {
1036         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1037                 return flow->addrs.v4addrs.src;
1038         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1039                 return (__force __be32)ipv6_addr_hash(
1040                         &flow->addrs.v6addrs.src);
1041         case FLOW_DISSECTOR_KEY_TIPC:
1042                 return flow->addrs.tipckey.key;
1043         default:
1044                 return 0;
1045         }
1046 }
1047 EXPORT_SYMBOL(flow_get_u32_src);
1048
1049 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1050 {
1051         switch (flow->control.addr_type) {
1052         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1053                 return flow->addrs.v4addrs.dst;
1054         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1055                 return (__force __be32)ipv6_addr_hash(
1056                         &flow->addrs.v6addrs.dst);
1057         default:
1058                 return 0;
1059         }
1060 }
1061 EXPORT_SYMBOL(flow_get_u32_dst);
1062
1063 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1064 {
1065         int addr_diff, i;
1066
1067         switch (keys->control.addr_type) {
1068         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1069                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1070                             (__force u32)keys->addrs.v4addrs.src;
1071                 if ((addr_diff < 0) ||
1072                     (addr_diff == 0 &&
1073                      ((__force u16)keys->ports.dst <
1074                       (__force u16)keys->ports.src))) {
1075                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1076                         swap(keys->ports.src, keys->ports.dst);
1077                 }
1078                 break;
1079         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1080                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1081                                    &keys->addrs.v6addrs.src,
1082                                    sizeof(keys->addrs.v6addrs.dst));
1083                 if ((addr_diff < 0) ||
1084                     (addr_diff == 0 &&
1085                      ((__force u16)keys->ports.dst <
1086                       (__force u16)keys->ports.src))) {
1087                         for (i = 0; i < 4; i++)
1088                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1089                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1090                         swap(keys->ports.src, keys->ports.dst);
1091                 }
1092                 break;
1093         }
1094 }
1095
1096 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1097 {
1098         u32 hash;
1099
1100         __flow_hash_consistentify(keys);
1101
1102         hash = __flow_hash_words(flow_keys_hash_start(keys),
1103                                  flow_keys_hash_length(keys), keyval);
1104         if (!hash)
1105                 hash = 1;
1106
1107         return hash;
1108 }
1109
1110 u32 flow_hash_from_keys(struct flow_keys *keys)
1111 {
1112         __flow_hash_secret_init();
1113         return __flow_hash_from_keys(keys, hashrnd);
1114 }
1115 EXPORT_SYMBOL(flow_hash_from_keys);
1116
1117 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1118                                   struct flow_keys *keys, u32 keyval)
1119 {
1120         skb_flow_dissect_flow_keys(skb, keys,
1121                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1122
1123         return __flow_hash_from_keys(keys, keyval);
1124 }
1125
1126 struct _flow_keys_digest_data {
1127         __be16  n_proto;
1128         u8      ip_proto;
1129         u8      padding;
1130         __be32  ports;
1131         __be32  src;
1132         __be32  dst;
1133 };
1134
1135 void make_flow_keys_digest(struct flow_keys_digest *digest,
1136                            const struct flow_keys *flow)
1137 {
1138         struct _flow_keys_digest_data *data =
1139             (struct _flow_keys_digest_data *)digest;
1140
1141         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1142
1143         memset(digest, 0, sizeof(*digest));
1144
1145         data->n_proto = flow->basic.n_proto;
1146         data->ip_proto = flow->basic.ip_proto;
1147         data->ports = flow->ports.ports;
1148         data->src = flow->addrs.v4addrs.src;
1149         data->dst = flow->addrs.v4addrs.dst;
1150 }
1151 EXPORT_SYMBOL(make_flow_keys_digest);
1152
1153 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1154
1155 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1156 {
1157         struct flow_keys keys;
1158
1159         __flow_hash_secret_init();
1160
1161         memset(&keys, 0, sizeof(keys));
1162         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1163                            NULL, 0, 0, 0,
1164                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1165
1166         return __flow_hash_from_keys(&keys, hashrnd);
1167 }
1168 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1169
1170 /**
1171  * __skb_get_hash: calculate a flow hash
1172  * @skb: sk_buff to calculate flow hash from
1173  *
1174  * This function calculates a flow hash based on src/dst addresses
1175  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1176  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1177  * if hash is a canonical 4-tuple hash over transport ports.
1178  */
1179 void __skb_get_hash(struct sk_buff *skb)
1180 {
1181         struct flow_keys keys;
1182         u32 hash;
1183
1184         __flow_hash_secret_init();
1185
1186         hash = ___skb_get_hash(skb, &keys, hashrnd);
1187
1188         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1189 }
1190 EXPORT_SYMBOL(__skb_get_hash);
1191
1192 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1193 {
1194         struct flow_keys keys;
1195
1196         return ___skb_get_hash(skb, &keys, perturb);
1197 }
1198 EXPORT_SYMBOL(skb_get_hash_perturb);
1199
1200 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1201                    const struct flow_keys *keys, int hlen)
1202 {
1203         u32 poff = keys->control.thoff;
1204
1205         /* skip L4 headers for fragments after the first */
1206         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1207             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1208                 return poff;
1209
1210         switch (keys->basic.ip_proto) {
1211         case IPPROTO_TCP: {
1212                 /* access doff as u8 to avoid unaligned access */
1213                 const u8 *doff;
1214                 u8 _doff;
1215
1216                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1217                                             data, hlen, &_doff);
1218                 if (!doff)
1219                         return poff;
1220
1221                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1222                 break;
1223         }
1224         case IPPROTO_UDP:
1225         case IPPROTO_UDPLITE:
1226                 poff += sizeof(struct udphdr);
1227                 break;
1228         /* For the rest, we do not really care about header
1229          * extensions at this point for now.
1230          */
1231         case IPPROTO_ICMP:
1232                 poff += sizeof(struct icmphdr);
1233                 break;
1234         case IPPROTO_ICMPV6:
1235                 poff += sizeof(struct icmp6hdr);
1236                 break;
1237         case IPPROTO_IGMP:
1238                 poff += sizeof(struct igmphdr);
1239                 break;
1240         case IPPROTO_DCCP:
1241                 poff += sizeof(struct dccp_hdr);
1242                 break;
1243         case IPPROTO_SCTP:
1244                 poff += sizeof(struct sctphdr);
1245                 break;
1246         }
1247
1248         return poff;
1249 }
1250
1251 /**
1252  * skb_get_poff - get the offset to the payload
1253  * @skb: sk_buff to get the payload offset from
1254  *
1255  * The function will get the offset to the payload as far as it could
1256  * be dissected.  The main user is currently BPF, so that we can dynamically
1257  * truncate packets without needing to push actual payload to the user
1258  * space and can analyze headers only, instead.
1259  */
1260 u32 skb_get_poff(const struct sk_buff *skb)
1261 {
1262         struct flow_keys keys;
1263
1264         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
1265                 return 0;
1266
1267         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1268 }
1269
1270 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1271 {
1272         memset(keys, 0, sizeof(*keys));
1273
1274         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1275             sizeof(keys->addrs.v6addrs.src));
1276         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1277             sizeof(keys->addrs.v6addrs.dst));
1278         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1279         keys->ports.src = fl6->fl6_sport;
1280         keys->ports.dst = fl6->fl6_dport;
1281         keys->keyid.keyid = fl6->fl6_gre_key;
1282         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1283         keys->basic.ip_proto = fl6->flowi6_proto;
1284
1285         return flow_hash_from_keys(keys);
1286 }
1287 EXPORT_SYMBOL(__get_hash_from_flowi6);
1288
1289 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
1290 {
1291         memset(keys, 0, sizeof(*keys));
1292
1293         keys->addrs.v4addrs.src = fl4->saddr;
1294         keys->addrs.v4addrs.dst = fl4->daddr;
1295         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1296         keys->ports.src = fl4->fl4_sport;
1297         keys->ports.dst = fl4->fl4_dport;
1298         keys->keyid.keyid = fl4->fl4_gre_key;
1299         keys->basic.ip_proto = fl4->flowi4_proto;
1300
1301         return flow_hash_from_keys(keys);
1302 }
1303 EXPORT_SYMBOL(__get_hash_from_flowi4);
1304
1305 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1306         {
1307                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1308                 .offset = offsetof(struct flow_keys, control),
1309         },
1310         {
1311                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1312                 .offset = offsetof(struct flow_keys, basic),
1313         },
1314         {
1315                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1316                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1317         },
1318         {
1319                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1320                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1321         },
1322         {
1323                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1324                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1325         },
1326         {
1327                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1328                 .offset = offsetof(struct flow_keys, ports),
1329         },
1330         {
1331                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1332                 .offset = offsetof(struct flow_keys, vlan),
1333         },
1334         {
1335                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1336                 .offset = offsetof(struct flow_keys, tags),
1337         },
1338         {
1339                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1340                 .offset = offsetof(struct flow_keys, keyid),
1341         },
1342 };
1343
1344 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1345         {
1346                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1347                 .offset = offsetof(struct flow_keys, control),
1348         },
1349         {
1350                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1351                 .offset = offsetof(struct flow_keys, basic),
1352         },
1353         {
1354                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1355                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1356         },
1357         {
1358                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1359                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1360         },
1361         {
1362                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1363                 .offset = offsetof(struct flow_keys, ports),
1364         },
1365 };
1366
1367 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
1368         {
1369                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1370                 .offset = offsetof(struct flow_keys, control),
1371         },
1372         {
1373                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1374                 .offset = offsetof(struct flow_keys, basic),
1375         },
1376 };
1377
1378 struct flow_dissector flow_keys_dissector __read_mostly;
1379 EXPORT_SYMBOL(flow_keys_dissector);
1380
1381 struct flow_dissector flow_keys_buf_dissector __read_mostly;
1382
1383 static int __init init_default_flow_dissectors(void)
1384 {
1385         skb_flow_dissector_init(&flow_keys_dissector,
1386                                 flow_keys_dissector_keys,
1387                                 ARRAY_SIZE(flow_keys_dissector_keys));
1388         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1389                                 flow_keys_dissector_symmetric_keys,
1390                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1391         skb_flow_dissector_init(&flow_keys_buf_dissector,
1392                                 flow_keys_buf_dissector_keys,
1393                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1394         return 0;
1395 }
1396
1397 core_initcall(init_default_flow_dissectors);