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/ip.h>
   8 #include <net/ipv6.h>
   9 #include <linux/igmp.h>
  10 #include <linux/icmp.h>
  11 #include <linux/sctp.h>
  12 #include <linux/dccp.h>
  13 #include <linux/if_tunnel.h>
  14 #include <linux/if_pppox.h>
  15 #include <linux/ppp_defs.h>
  16 #include <linux/stddef.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/mpls.h>
  19 #include <net/flow_dissector.h>
  20 #include <scsi/fc/fc_fcoe.h>
  21
  22 static bool dissector_uses_key(const struct flow_dissector *flow_dissector,
  23                                enum flow_dissector_key_id key_id)
  24 {
  25         return flow_dissector->used_keys & (1 << key_id);
  26 }
  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 static void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
  35                                        enum flow_dissector_key_id key_id,
  36                                        void *target_container)
  37 {
  38         return ((char *) target_container) + flow_dissector->offset[key_id];
  39 }
  40
  41 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  42                              const struct flow_dissector_key *key,
  43                              unsigned int key_count)
  44 {
  45         unsigned int i;
  46
  47         memset(flow_dissector, 0, sizeof(*flow_dissector));
  48
  49         for (i = 0; i < key_count; i++, key++) {
  50                 /* User should make sure that every key target offset is withing
  51                  * boundaries of unsigned short.
  52                  */
  53                 BUG_ON(key->offset > USHRT_MAX);
  54                 BUG_ON(dissector_uses_key(flow_dissector,
  55                                           key->key_id));
  56
  57                 dissector_set_key(flow_dissector, key->key_id);
  58                 flow_dissector->offset[key->key_id] = key->offset;
  59         }
  60
  61         /* Ensure that the dissector always includes control and basic key.
  62          * That way we are able to avoid handling lack of these in fast path.
  63          */
  64         BUG_ON(!dissector_uses_key(flow_dissector,
  65                                    FLOW_DISSECTOR_KEY_CONTROL));
  66         BUG_ON(!dissector_uses_key(flow_dissector,
  67                                    FLOW_DISSECTOR_KEY_BASIC));
  68 }
  69 EXPORT_SYMBOL(skb_flow_dissector_init);
  70
  71 /**
  72  * __skb_flow_get_ports - extract the upper layer ports and return them
  73  * @skb: sk_buff to extract the ports from
  74  * @thoff: transport header offset
  75  * @ip_proto: protocol for which to get port offset
  76  * @data: raw buffer pointer to the packet, if NULL use skb->data
  77  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  78  *
  79  * The function will try to retrieve the ports at offset thoff + poff where poff
  80  * is the protocol port offset returned from proto_ports_offset
  81  */
  82 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  83                             void *data, int hlen)
  84 {
  85         int poff = proto_ports_offset(ip_proto);
  86
  87         if (!data) {
  88                 data = skb->data;
  89                 hlen = skb_headlen(skb);
  90         }
  91
  92         if (poff >= 0) {
  93                 __be32 *ports, _ports;
  94
  95                 ports = __skb_header_pointer(skb, thoff + poff,
  96                                              sizeof(_ports), data, hlen, &_ports);
  97                 if (ports)
  98                         return *ports;
  99         }
 100
 101         return 0;
 102 }
 103 EXPORT_SYMBOL(__skb_flow_get_ports);
 104
 105 /**
 106  * __skb_flow_dissect - extract the flow_keys struct and return it
 107  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 108  * @flow_dissector: list of keys to dissect
 109  * @target_container: target structure to put dissected values into
 110  * @data: raw buffer pointer to the packet, if NULL use skb->data
 111  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 112  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 113  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 114  *
 115  * The function will try to retrieve individual keys into target specified
 116  * by flow_dissector from either the skbuff or a raw buffer specified by the
 117  * rest parameters.
 118  *
 119  * Caller must take care of zeroing target container memory.
 120  */
 121 bool __skb_flow_dissect(const struct sk_buff *skb,
 122                         struct flow_dissector *flow_dissector,
 123                         void *target_container,
 124                         void *data, __be16 proto, int nhoff, int hlen,
 125                         unsigned int flags)
 126 {
 127         struct flow_dissector_key_control *key_control;
 128         struct flow_dissector_key_basic *key_basic;
 129         struct flow_dissector_key_addrs *key_addrs;
 130         struct flow_dissector_key_ports *key_ports;
 131         struct flow_dissector_key_tags *key_tags;
 132         struct flow_dissector_key_keyid *key_keyid;
 133         u8 ip_proto = 0;
 134         bool ret = false;
 135
 136         if (!data) {
 137                 data = skb->data;
 138                 proto = skb->protocol;
 139                 nhoff = skb_network_offset(skb);
 140                 hlen = skb_headlen(skb);
 141         }
 142
 143         /* It is ensured by skb_flow_dissector_init() that control key will
 144          * be always present.
 145          */
 146         key_control = skb_flow_dissector_target(flow_dissector,
 147                                                 FLOW_DISSECTOR_KEY_CONTROL,
 148                                                 target_container);
 149
 150         /* It is ensured by skb_flow_dissector_init() that basic key will
 151          * be always present.
 152          */
 153         key_basic = skb_flow_dissector_target(flow_dissector,
 154                                               FLOW_DISSECTOR_KEY_BASIC,
 155                                               target_container);
 156
 157         if (dissector_uses_key(flow_dissector,
 158                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 159                 struct ethhdr *eth = eth_hdr(skb);
 160                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 161
 162                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 163                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 164                                                           target_container);
 165                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 166         }
 167
 168 again:
 169         switch (proto) {
 170         case htons(ETH_P_IP): {
 171                 const struct iphdr *iph;
 172                 struct iphdr _iph;
 173 ip:
 174                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 175                 if (!iph || iph->ihl < 5)
 176                         goto out_bad;
 177                 nhoff += iph->ihl * 4;
 178
 179                 ip_proto = iph->protocol;
 180
 181                 if (dissector_uses_key(flow_dissector,
 182                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 183                         key_addrs = skb_flow_dissector_target(flow_dissector,
 184                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 185                                                               target_container);
 186
 187                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 188                                sizeof(key_addrs->v4addrs));
 189                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 190                 }
 191
 192                 if (ip_is_fragment(iph)) {
 193                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 194
 195                         if (iph->frag_off & htons(IP_OFFSET)) {
 196                                 goto out_good;
 197                         } else {
 198                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 199                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 200                                         goto out_good;
 201                         }
 202                 }
 203
 204                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 205                         goto out_good;
 206
 207                 break;
 208         }
 209         case htons(ETH_P_IPV6): {
 210                 const struct ipv6hdr *iph;
 211                 struct ipv6hdr _iph;
 212
 213 ipv6:
 214                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 215                 if (!iph)
 216                         goto out_bad;
 217
 218                 ip_proto = iph->nexthdr;
 219                 nhoff += sizeof(struct ipv6hdr);
 220
 221                 if (dissector_uses_key(flow_dissector,
 222                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 223                         struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs;
 224
 225                         key_ipv6_addrs = skb_flow_dissector_target(flow_dissector,
 226                                                                    FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 227                                                                    target_container);
 228
 229                         memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
 230                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 231                 }
 232
 233                 if ((dissector_uses_key(flow_dissector,
 234                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 235                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 236                     ip6_flowlabel(iph)) {
 237                         __be32 flow_label = ip6_flowlabel(iph);
 238
 239                         if (dissector_uses_key(flow_dissector,
 240                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 241                                 key_tags = skb_flow_dissector_target(flow_dissector,
 242                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 243                                                                      target_container);
 244                                 key_tags->flow_label = ntohl(flow_label);
 245                         }
 246                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 247                                 goto out_good;
 248                 }
 249
 250                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 251                         goto out_good;
 252
 253                 break;
 254         }
 255         case htons(ETH_P_8021AD):
 256         case htons(ETH_P_8021Q): {
 257                 const struct vlan_hdr *vlan;
 258                 struct vlan_hdr _vlan;
 259
 260                 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
 261                 if (!vlan)
 262                         goto out_bad;
 263
 264                 if (dissector_uses_key(flow_dissector,
 265                                        FLOW_DISSECTOR_KEY_VLANID)) {
 266                         key_tags = skb_flow_dissector_target(flow_dissector,
 267                                                              FLOW_DISSECTOR_KEY_VLANID,
 268                                                              target_container);
 269
 270                         key_tags->vlan_id = skb_vlan_tag_get_id(skb);
 271                 }
 272
 273                 proto = vlan->h_vlan_encapsulated_proto;
 274                 nhoff += sizeof(*vlan);
 275                 goto again;
 276         }
 277         case htons(ETH_P_PPP_SES): {
 278                 struct {
 279                         struct pppoe_hdr hdr;
 280                         __be16 proto;
 281                 } *hdr, _hdr;
 282                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 283                 if (!hdr)
 284                         goto out_bad;
 285                 proto = hdr->proto;
 286                 nhoff += PPPOE_SES_HLEN;
 287                 switch (proto) {
 288                 case htons(PPP_IP):
 289                         goto ip;
 290                 case htons(PPP_IPV6):
 291                         goto ipv6;
 292                 default:
 293                         goto out_bad;
 294                 }
 295         }
 296         case htons(ETH_P_TIPC): {
 297                 struct {
 298                         __be32 pre[3];
 299                         __be32 srcnode;
 300                 } *hdr, _hdr;
 301                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 302                 if (!hdr)
 303                         goto out_bad;
 304
 305                 if (dissector_uses_key(flow_dissector,
 306                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 307                         key_addrs = skb_flow_dissector_target(flow_dissector,
 308                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 309                                                               target_container);
 310                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 311                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 312                 }
 313                 goto out_good;
 314         }
 315
 316         case htons(ETH_P_MPLS_UC):
 317         case htons(ETH_P_MPLS_MC): {
 318                 struct mpls_label *hdr, _hdr[2];
 319 mpls:
 320                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 321                                            hlen, &_hdr);
 322                 if (!hdr)
 323                         goto out_bad;
 324
 325                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 326                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 327                         if (dissector_uses_key(flow_dissector,
 328                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 329                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 330                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 331                                                                       target_container);
 332                                 key_keyid->keyid = hdr[1].entry &
 333                                         htonl(MPLS_LS_LABEL_MASK);
 334                         }
 335
 336                         goto out_good;
 337                 }
 338
 339                 goto out_good;
 340         }
 341
 342         case htons(ETH_P_FCOE):
 343                 if ((hlen - nhoff) < FCOE_HEADER_LEN)
 344                         goto out_bad;
 345
 346                 nhoff += FCOE_HEADER_LEN;
 347                 goto out_good;
 348         default:
 349                 goto out_bad;
 350         }
 351
 352 ip_proto_again:
 353         switch (ip_proto) {
 354         case IPPROTO_GRE: {
 355                 struct gre_hdr {
 356                         __be16 flags;
 357                         __be16 proto;
 358                 } *hdr, _hdr;
 359
 360                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 361                 if (!hdr)
 362                         goto out_bad;
 363                 /*
 364                  * Only look inside GRE if version zero and no
 365                  * routing
 366                  */
 367                 if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
 368                         break;
 369
 370                 proto = hdr->proto;
 371                 nhoff += 4;
 372                 if (hdr->flags & GRE_CSUM)
 373                         nhoff += 4;
 374                 if (hdr->flags & GRE_KEY) {
 375                         const __be32 *keyid;
 376                         __be32 _keyid;
 377
 378                         keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
 379                                                      data, hlen, &_keyid);
 380
 381                         if (!keyid)
 382                                 goto out_bad;
 383
 384                         if (dissector_uses_key(flow_dissector,
 385                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 386                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 387                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 388                                                                       target_container);
 389                                 key_keyid->keyid = *keyid;
 390                         }
 391                         nhoff += 4;
 392                 }
 393                 if (hdr->flags & GRE_SEQ)
 394                         nhoff += 4;
 395                 if (proto == htons(ETH_P_TEB)) {
 396                         const struct ethhdr *eth;
 397                         struct ethhdr _eth;
 398
 399                         eth = __skb_header_pointer(skb, nhoff,
 400                                                    sizeof(_eth),
 401                                                    data, hlen, &_eth);
 402                         if (!eth)
 403                                 goto out_bad;
 404                         proto = eth->h_proto;
 405                         nhoff += sizeof(*eth);
 406
 407                         /* Cap headers that we access via pointers at the
 408                          * end of the Ethernet header as our maximum alignment
 409                          * at that point is only 2 bytes.
 410                          */
 411                         if (NET_IP_ALIGN)
 412                                 hlen = nhoff;
 413                 }
 414
 415                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 416                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 417                         goto out_good;
 418
 419                 goto again;
 420         }
 421         case NEXTHDR_HOP:
 422         case NEXTHDR_ROUTING:
 423         case NEXTHDR_DEST: {
 424                 u8 _opthdr[2], *opthdr;
 425
 426                 if (proto != htons(ETH_P_IPV6))
 427                         break;
 428
 429                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 430                                               data, hlen, &_opthdr);
 431                 if (!opthdr)
 432                         goto out_bad;
 433
 434                 ip_proto = opthdr[0];
 435                 nhoff += (opthdr[1] + 1) << 3;
 436
 437                 goto ip_proto_again;
 438         }
 439         case NEXTHDR_FRAGMENT: {
 440                 struct frag_hdr _fh, *fh;
 441
 442                 if (proto != htons(ETH_P_IPV6))
 443                         break;
 444
 445                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 446                                           data, hlen, &_fh);
 447
 448                 if (!fh)
 449                         goto out_bad;
 450
 451                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 452
 453                 nhoff += sizeof(_fh);
 454                 ip_proto = fh->nexthdr;
 455
 456                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 457                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 458                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
 459                                 goto ip_proto_again;
 460                 }
 461                 goto out_good;
 462         }
 463         case IPPROTO_IPIP:
 464                 proto = htons(ETH_P_IP);
 465
 466                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 467                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 468                         goto out_good;
 469
 470                 goto ip;
 471         case IPPROTO_IPV6:
 472                 proto = htons(ETH_P_IPV6);
 473
 474                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 475                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 476                         goto out_good;
 477
 478                 goto ipv6;
 479         case IPPROTO_MPLS:
 480                 proto = htons(ETH_P_MPLS_UC);
 481                 goto mpls;
 482         default:
 483                 break;
 484         }
 485
 486         if (dissector_uses_key(flow_dissector,
 487                                FLOW_DISSECTOR_KEY_PORTS)) {
 488                 key_ports = skb_flow_dissector_target(flow_dissector,
 489                                                       FLOW_DISSECTOR_KEY_PORTS,
 490                                                       target_container);
 491                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 492                                                         data, hlen);
 493         }
 494
 495 out_good:
 496         ret = true;
 497
 498 out_bad:
 499         key_basic->n_proto = proto;
 500         key_basic->ip_proto = ip_proto;
 501         key_control->thoff = (u16)nhoff;
 502
 503         return ret;
 504 }
 505 EXPORT_SYMBOL(__skb_flow_dissect);
 506
 507 static u32 hashrnd __read_mostly;
 508 static __always_inline void __flow_hash_secret_init(void)
 509 {
 510         net_get_random_once(&hashrnd, sizeof(hashrnd));
 511 }
 512
 513 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 514                                              u32 keyval)
 515 {
 516         return jhash2(words, length, keyval);
 517 }
 518
 519 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
 520 {
 521         const void *p = flow;
 522
 523         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 524         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
 525 }
 526
 527 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 528 {
 529         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 530         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 531         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 532                      sizeof(*flow) - sizeof(flow->addrs));
 533
 534         switch (flow->control.addr_type) {
 535         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 536                 diff -= sizeof(flow->addrs.v4addrs);
 537                 break;
 538         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 539                 diff -= sizeof(flow->addrs.v6addrs);
 540                 break;
 541         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 542                 diff -= sizeof(flow->addrs.tipcaddrs);
 543                 break;
 544         }
 545         return (sizeof(*flow) - diff) / sizeof(u32);
 546 }
 547
 548 __be32 flow_get_u32_src(const struct flow_keys *flow)
 549 {
 550         switch (flow->control.addr_type) {
 551         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 552                 return flow->addrs.v4addrs.src;
 553         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 554                 return (__force __be32)ipv6_addr_hash(
 555                         &flow->addrs.v6addrs.src);
 556         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 557                 return flow->addrs.tipcaddrs.srcnode;
 558         default:
 559                 return 0;
 560         }
 561 }
 562 EXPORT_SYMBOL(flow_get_u32_src);
 563
 564 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 565 {
 566         switch (flow->control.addr_type) {
 567         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 568                 return flow->addrs.v4addrs.dst;
 569         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 570                 return (__force __be32)ipv6_addr_hash(
 571                         &flow->addrs.v6addrs.dst);
 572         default:
 573                 return 0;
 574         }
 575 }
 576 EXPORT_SYMBOL(flow_get_u32_dst);
 577
 578 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 579 {
 580         int addr_diff, i;
 581
 582         switch (keys->control.addr_type) {
 583         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 584                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 585                             (__force u32)keys->addrs.v4addrs.src;
 586                 if ((addr_diff < 0) ||
 587                     (addr_diff == 0 &&
 588                      ((__force u16)keys->ports.dst <
 589                       (__force u16)keys->ports.src))) {
 590                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 591                         swap(keys->ports.src, keys->ports.dst);
 592                 }
 593                 break;
 594         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 595                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 596                                    &keys->addrs.v6addrs.src,
 597                                    sizeof(keys->addrs.v6addrs.dst));
 598                 if ((addr_diff < 0) ||
 599                     (addr_diff == 0 &&
 600                      ((__force u16)keys->ports.dst <
 601                       (__force u16)keys->ports.src))) {
 602                         for (i = 0; i < 4; i++)
 603                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 604                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 605                         swap(keys->ports.src, keys->ports.dst);
 606                 }
 607                 break;
 608         }
 609 }
 610
 611 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 612 {
 613         u32 hash;
 614
 615         __flow_hash_consistentify(keys);
 616
 617         hash = __flow_hash_words(flow_keys_hash_start(keys),
 618                                  flow_keys_hash_length(keys), keyval);
 619         if (!hash)
 620                 hash = 1;
 621
 622         return hash;
 623 }
 624
 625 u32 flow_hash_from_keys(struct flow_keys *keys)
 626 {
 627         __flow_hash_secret_init();
 628         return __flow_hash_from_keys(keys, hashrnd);
 629 }
 630 EXPORT_SYMBOL(flow_hash_from_keys);
 631
 632 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 633                                   struct flow_keys *keys, u32 keyval)
 634 {
 635         skb_flow_dissect_flow_keys(skb, keys,
 636                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 637
 638         return __flow_hash_from_keys(keys, keyval);
 639 }
 640
 641 struct _flow_keys_digest_data {
 642         __be16  n_proto;
 643         u8      ip_proto;
 644         u8      padding;
 645         __be32  ports;
 646         __be32  src;
 647         __be32  dst;
 648 };
 649
 650 void make_flow_keys_digest(struct flow_keys_digest *digest,
 651                            const struct flow_keys *flow)
 652 {
 653         struct _flow_keys_digest_data *data =
 654             (struct _flow_keys_digest_data *)digest;
 655
 656         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 657
 658         memset(digest, 0, sizeof(*digest));
 659
 660         data->n_proto = flow->basic.n_proto;
 661         data->ip_proto = flow->basic.ip_proto;
 662         data->ports = flow->ports.ports;
 663         data->src = flow->addrs.v4addrs.src;
 664         data->dst = flow->addrs.v4addrs.dst;
 665 }
 666 EXPORT_SYMBOL(make_flow_keys_digest);
 667
 668 /**
 669  * __skb_get_hash: calculate a flow hash
 670  * @skb: sk_buff to calculate flow hash from
 671  *
 672  * This function calculates a flow hash based on src/dst addresses
 673  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 674  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 675  * if hash is a canonical 4-tuple hash over transport ports.
 676  */
 677 void __skb_get_hash(struct sk_buff *skb)
 678 {
 679         struct flow_keys keys;
 680
 681         __flow_hash_secret_init();
 682
 683         __skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd),
 684                           flow_keys_have_l4(&keys));
 685 }
 686 EXPORT_SYMBOL(__skb_get_hash);
 687
 688 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 689 {
 690         struct flow_keys keys;
 691
 692         return ___skb_get_hash(skb, &keys, perturb);
 693 }
 694 EXPORT_SYMBOL(skb_get_hash_perturb);
 695
 696 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 697 {
 698         struct flow_keys keys;
 699
 700         memset(&keys, 0, sizeof(keys));
 701
 702         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 703                sizeof(keys.addrs.v6addrs.src));
 704         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 705                sizeof(keys.addrs.v6addrs.dst));
 706         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 707         keys.ports.src = fl6->fl6_sport;
 708         keys.ports.dst = fl6->fl6_dport;
 709         keys.keyid.keyid = fl6->fl6_gre_key;
 710         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 711         keys.basic.ip_proto = fl6->flowi6_proto;
 712
 713         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 714                           flow_keys_have_l4(&keys));
 715
 716         return skb->hash;
 717 }
 718 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 719
 720 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 721 {
 722         struct flow_keys keys;
 723
 724         memset(&keys, 0, sizeof(keys));
 725
 726         keys.addrs.v4addrs.src = fl4->saddr;
 727         keys.addrs.v4addrs.dst = fl4->daddr;
 728         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 729         keys.ports.src = fl4->fl4_sport;
 730         keys.ports.dst = fl4->fl4_dport;
 731         keys.keyid.keyid = fl4->fl4_gre_key;
 732         keys.basic.ip_proto = fl4->flowi4_proto;
 733
 734         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 735                           flow_keys_have_l4(&keys));
 736
 737         return skb->hash;
 738 }
 739 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 740
 741 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 742                    const struct flow_keys *keys, int hlen)
 743 {
 744         u32 poff = keys->control.thoff;
 745
 746         /* skip L4 headers for fragments after the first */
 747         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
 748             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
 749                 return poff;
 750
 751         switch (keys->basic.ip_proto) {
 752         case IPPROTO_TCP: {
 753                 /* access doff as u8 to avoid unaligned access */
 754                 const u8 *doff;
 755                 u8 _doff;
 756
 757                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 758                                             data, hlen, &_doff);
 759                 if (!doff)
 760                         return poff;
 761
 762                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 763                 break;
 764         }
 765         case IPPROTO_UDP:
 766         case IPPROTO_UDPLITE:
 767                 poff += sizeof(struct udphdr);
 768                 break;
 769         /* For the rest, we do not really care about header
 770          * extensions at this point for now.
 771          */
 772         case IPPROTO_ICMP:
 773                 poff += sizeof(struct icmphdr);
 774                 break;
 775         case IPPROTO_ICMPV6:
 776                 poff += sizeof(struct icmp6hdr);
 777                 break;
 778         case IPPROTO_IGMP:
 779                 poff += sizeof(struct igmphdr);
 780                 break;
 781         case IPPROTO_DCCP:
 782                 poff += sizeof(struct dccp_hdr);
 783                 break;
 784         case IPPROTO_SCTP:
 785                 poff += sizeof(struct sctphdr);
 786                 break;
 787         }
 788
 789         return poff;
 790 }
 791
 792 /**
 793  * skb_get_poff - get the offset to the payload
 794  * @skb: sk_buff to get the payload offset from
 795  *
 796  * The function will get the offset to the payload as far as it could
 797  * be dissected.  The main user is currently BPF, so that we can dynamically
 798  * truncate packets without needing to push actual payload to the user
 799  * space and can analyze headers only, instead.
 800  */
 801 u32 skb_get_poff(const struct sk_buff *skb)
 802 {
 803         struct flow_keys keys;
 804
 805         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 806                 return 0;
 807
 808         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 809 }
 810
 811 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 812 {
 813         memset(keys, 0, sizeof(*keys));
 814
 815         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 816             sizeof(keys->addrs.v6addrs.src));
 817         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 818             sizeof(keys->addrs.v6addrs.dst));
 819         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 820         keys->ports.src = fl6->fl6_sport;
 821         keys->ports.dst = fl6->fl6_dport;
 822         keys->keyid.keyid = fl6->fl6_gre_key;
 823         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 824         keys->basic.ip_proto = fl6->flowi6_proto;
 825
 826         return flow_hash_from_keys(keys);
 827 }
 828 EXPORT_SYMBOL(__get_hash_from_flowi6);
 829
 830 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 831 {
 832         memset(keys, 0, sizeof(*keys));
 833
 834         keys->addrs.v4addrs.src = fl4->saddr;
 835         keys->addrs.v4addrs.dst = fl4->daddr;
 836         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 837         keys->ports.src = fl4->fl4_sport;
 838         keys->ports.dst = fl4->fl4_dport;
 839         keys->keyid.keyid = fl4->fl4_gre_key;
 840         keys->basic.ip_proto = fl4->flowi4_proto;
 841
 842         return flow_hash_from_keys(keys);
 843 }
 844 EXPORT_SYMBOL(__get_hash_from_flowi4);
 845
 846 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 847         {
 848                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 849                 .offset = offsetof(struct flow_keys, control),
 850         },
 851         {
 852                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 853                 .offset = offsetof(struct flow_keys, basic),
 854         },
 855         {
 856                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 857                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 858         },
 859         {
 860                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 861                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 862         },
 863         {
 864                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 865                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 866         },
 867         {
 868                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 869                 .offset = offsetof(struct flow_keys, ports),
 870         },
 871         {
 872                 .key_id = FLOW_DISSECTOR_KEY_VLANID,
 873                 .offset = offsetof(struct flow_keys, tags),
 874         },
 875         {
 876                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 877                 .offset = offsetof(struct flow_keys, tags),
 878         },
 879         {
 880                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 881                 .offset = offsetof(struct flow_keys, keyid),
 882         },
 883 };
 884
 885 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 886         {
 887                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 888                 .offset = offsetof(struct flow_keys, control),
 889         },
 890         {
 891                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 892                 .offset = offsetof(struct flow_keys, basic),
 893         },
 894 };
 895
 896 struct flow_dissector flow_keys_dissector __read_mostly;
 897 EXPORT_SYMBOL(flow_keys_dissector);
 898
 899 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 900
 901 static int __init init_default_flow_dissectors(void)
 902 {
 903         skb_flow_dissector_init(&flow_keys_dissector,
 904                                 flow_keys_dissector_keys,
 905                                 ARRAY_SIZE(flow_keys_dissector_keys));
 906         skb_flow_dissector_init(&flow_keys_buf_dissector,
 907                                 flow_keys_buf_dissector_keys,
 908                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
 909         return 0;
 910 }
 911
 912 late_initcall_sync(init_default_flow_dissectors);