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 <net/gre.h>
  10 #include <net/pptp.h>
  11 #include <linux/igmp.h>
  12 #include <linux/icmp.h>
  13 #include <linux/sctp.h>
  14 #include <linux/dccp.h>
  15 #include <linux/if_tunnel.h>
  16 #include <linux/if_pppox.h>
  17 #include <linux/ppp_defs.h>
  18 #include <linux/stddef.h>
  19 #include <linux/if_ether.h>
  20 #include <linux/mpls.h>
  21 #include <net/flow_dissector.h>
  22 #include <scsi/fc/fc_fcoe.h>
  23
  24 static void dissector_set_key(struct flow_dissector *flow_dissector,
  25                               enum flow_dissector_key_id key_id)
  26 {
  27         flow_dissector->used_keys |= (1 << key_id);
  28 }
  29
  30 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  31                              const struct flow_dissector_key *key,
  32                              unsigned int key_count)
  33 {
  34         unsigned int i;
  35
  36         memset(flow_dissector, 0, sizeof(*flow_dissector));
  37
  38         for (i = 0; i < key_count; i++, key++) {
  39                 /* User should make sure that every key target offset is withing
  40                  * boundaries of unsigned short.
  41                  */
  42                 BUG_ON(key->offset > USHRT_MAX);
  43                 BUG_ON(dissector_uses_key(flow_dissector,
  44                                           key->key_id));
  45
  46                 dissector_set_key(flow_dissector, key->key_id);
  47                 flow_dissector->offset[key->key_id] = key->offset;
  48         }
  49
  50         /* Ensure that the dissector always includes control and basic key.
  51          * That way we are able to avoid handling lack of these in fast path.
  52          */
  53         BUG_ON(!dissector_uses_key(flow_dissector,
  54                                    FLOW_DISSECTOR_KEY_CONTROL));
  55         BUG_ON(!dissector_uses_key(flow_dissector,
  56                                    FLOW_DISSECTOR_KEY_BASIC));
  57 }
  58 EXPORT_SYMBOL(skb_flow_dissector_init);
  59
  60 /**
  61  * __skb_flow_get_ports - extract the upper layer ports and return them
  62  * @skb: sk_buff to extract the ports from
  63  * @thoff: transport header offset
  64  * @ip_proto: protocol for which to get port offset
  65  * @data: raw buffer pointer to the packet, if NULL use skb->data
  66  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  67  *
  68  * The function will try to retrieve the ports at offset thoff + poff where poff
  69  * is the protocol port offset returned from proto_ports_offset
  70  */
  71 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  72                             void *data, int hlen)
  73 {
  74         int poff = proto_ports_offset(ip_proto);
  75
  76         if (!data) {
  77                 data = skb->data;
  78                 hlen = skb_headlen(skb);
  79         }
  80
  81         if (poff >= 0) {
  82                 __be32 *ports, _ports;
  83
  84                 ports = __skb_header_pointer(skb, thoff + poff,
  85                                              sizeof(_ports), data, hlen, &_ports);
  86                 if (ports)
  87                         return *ports;
  88         }
  89
  90         return 0;
  91 }
  92 EXPORT_SYMBOL(__skb_flow_get_ports);
  93
  94 /**
  95  * __skb_flow_dissect - extract the flow_keys struct and return it
  96  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
  97  * @flow_dissector: list of keys to dissect
  98  * @target_container: target structure to put dissected values into
  99  * @data: raw buffer pointer to the packet, if NULL use skb->data
 100  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 101  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 102  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 103  *
 104  * The function will try to retrieve individual keys into target specified
 105  * by flow_dissector from either the skbuff or a raw buffer specified by the
 106  * rest parameters.
 107  *
 108  * Caller must take care of zeroing target container memory.
 109  */
 110 bool __skb_flow_dissect(const struct sk_buff *skb,
 111                         struct flow_dissector *flow_dissector,
 112                         void *target_container,
 113                         void *data, __be16 proto, int nhoff, int hlen,
 114                         unsigned int flags)
 115 {
 116         struct flow_dissector_key_control *key_control;
 117         struct flow_dissector_key_basic *key_basic;
 118         struct flow_dissector_key_addrs *key_addrs;
 119         struct flow_dissector_key_ports *key_ports;
 120         struct flow_dissector_key_tags *key_tags;
 121         struct flow_dissector_key_keyid *key_keyid;
 122         u8 ip_proto = 0;
 123         bool ret = false;
 124
 125         if (!data) {
 126                 data = skb->data;
 127                 proto = skb->protocol;
 128                 nhoff = skb_network_offset(skb);
 129                 hlen = skb_headlen(skb);
 130         }
 131
 132         /* It is ensured by skb_flow_dissector_init() that control key will
 133          * be always present.
 134          */
 135         key_control = skb_flow_dissector_target(flow_dissector,
 136                                                 FLOW_DISSECTOR_KEY_CONTROL,
 137                                                 target_container);
 138
 139         /* It is ensured by skb_flow_dissector_init() that basic key will
 140          * be always present.
 141          */
 142         key_basic = skb_flow_dissector_target(flow_dissector,
 143                                               FLOW_DISSECTOR_KEY_BASIC,
 144                                               target_container);
 145
 146         if (dissector_uses_key(flow_dissector,
 147                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 148                 struct ethhdr *eth = eth_hdr(skb);
 149                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 150
 151                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 152                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 153                                                           target_container);
 154                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 155         }
 156
 157 again:
 158         switch (proto) {
 159         case htons(ETH_P_IP): {
 160                 const struct iphdr *iph;
 161                 struct iphdr _iph;
 162 ip:
 163                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 164                 if (!iph || iph->ihl < 5)
 165                         goto out_bad;
 166                 nhoff += iph->ihl * 4;
 167
 168                 ip_proto = iph->protocol;
 169
 170                 if (dissector_uses_key(flow_dissector,
 171                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 172                         key_addrs = skb_flow_dissector_target(flow_dissector,
 173                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 174                                                               target_container);
 175
 176                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 177                                sizeof(key_addrs->v4addrs));
 178                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 179                 }
 180
 181                 if (ip_is_fragment(iph)) {
 182                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 183
 184                         if (iph->frag_off & htons(IP_OFFSET)) {
 185                                 goto out_good;
 186                         } else {
 187                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 188                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 189                                         goto out_good;
 190                         }
 191                 }
 192
 193                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 194                         goto out_good;
 195
 196                 break;
 197         }
 198         case htons(ETH_P_IPV6): {
 199                 const struct ipv6hdr *iph;
 200                 struct ipv6hdr _iph;
 201
 202 ipv6:
 203                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 204                 if (!iph)
 205                         goto out_bad;
 206
 207                 ip_proto = iph->nexthdr;
 208                 nhoff += sizeof(struct ipv6hdr);
 209
 210                 if (dissector_uses_key(flow_dissector,
 211                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 212                         key_addrs = skb_flow_dissector_target(flow_dissector,
 213                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 214                                                               target_container);
 215
 216                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 217                                sizeof(key_addrs->v6addrs));
 218                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 219                 }
 220
 221                 if ((dissector_uses_key(flow_dissector,
 222                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 223                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 224                     ip6_flowlabel(iph)) {
 225                         __be32 flow_label = ip6_flowlabel(iph);
 226
 227                         if (dissector_uses_key(flow_dissector,
 228                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 229                                 key_tags = skb_flow_dissector_target(flow_dissector,
 230                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 231                                                                      target_container);
 232                                 key_tags->flow_label = ntohl(flow_label);
 233                         }
 234                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 235                                 goto out_good;
 236                 }
 237
 238                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 239                         goto out_good;
 240
 241                 break;
 242         }
 243         case htons(ETH_P_8021AD):
 244         case htons(ETH_P_8021Q): {
 245                 const struct vlan_hdr *vlan;
 246                 struct vlan_hdr _vlan;
 247
 248                 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
 249                 if (!vlan)
 250                         goto out_bad;
 251
 252                 if (dissector_uses_key(flow_dissector,
 253                                        FLOW_DISSECTOR_KEY_VLANID)) {
 254                         key_tags = skb_flow_dissector_target(flow_dissector,
 255                                                              FLOW_DISSECTOR_KEY_VLANID,
 256                                                              target_container);
 257
 258                         key_tags->vlan_id = skb_vlan_tag_get_id(skb);
 259                 }
 260
 261                 proto = vlan->h_vlan_encapsulated_proto;
 262                 nhoff += sizeof(*vlan);
 263                 goto again;
 264         }
 265         case htons(ETH_P_PPP_SES): {
 266                 struct {
 267                         struct pppoe_hdr hdr;
 268                         __be16 proto;
 269                 } *hdr, _hdr;
 270                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 271                 if (!hdr)
 272                         goto out_bad;
 273                 proto = hdr->proto;
 274                 nhoff += PPPOE_SES_HLEN;
 275                 switch (proto) {
 276                 case htons(PPP_IP):
 277                         goto ip;
 278                 case htons(PPP_IPV6):
 279                         goto ipv6;
 280                 default:
 281                         goto out_bad;
 282                 }
 283         }
 284         case htons(ETH_P_TIPC): {
 285                 struct {
 286                         __be32 pre[3];
 287                         __be32 srcnode;
 288                 } *hdr, _hdr;
 289                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 290                 if (!hdr)
 291                         goto out_bad;
 292
 293                 if (dissector_uses_key(flow_dissector,
 294                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 295                         key_addrs = skb_flow_dissector_target(flow_dissector,
 296                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 297                                                               target_container);
 298                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 299                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 300                 }
 301                 goto out_good;
 302         }
 303
 304         case htons(ETH_P_MPLS_UC):
 305         case htons(ETH_P_MPLS_MC): {
 306                 struct mpls_label *hdr, _hdr[2];
 307 mpls:
 308                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 309                                            hlen, &_hdr);
 310                 if (!hdr)
 311                         goto out_bad;
 312
 313                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 314                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 315                         if (dissector_uses_key(flow_dissector,
 316                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 317                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 318                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 319                                                                       target_container);
 320                                 key_keyid->keyid = hdr[1].entry &
 321                                         htonl(MPLS_LS_LABEL_MASK);
 322                         }
 323
 324                         goto out_good;
 325                 }
 326
 327                 goto out_good;
 328         }
 329
 330         case htons(ETH_P_FCOE):
 331                 if ((hlen - nhoff) < FCOE_HEADER_LEN)
 332                         goto out_bad;
 333
 334                 nhoff += FCOE_HEADER_LEN;
 335                 goto out_good;
 336         default:
 337                 goto out_bad;
 338         }
 339
 340 ip_proto_again:
 341         switch (ip_proto) {
 342         case IPPROTO_GRE: {
 343                 struct gre_base_hdr *hdr, _hdr;
 344                 u16 gre_ver;
 345                 int offset = 0;
 346
 347                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 348                 if (!hdr)
 349                         goto out_bad;
 350
 351                 /* Only look inside GRE without routing */
 352                 if (hdr->flags & GRE_ROUTING)
 353                         break;
 354
 355                 /* Only look inside GRE for version 0 and 1 */
 356                 gre_ver = ntohs(hdr->flags & GRE_VERSION);
 357                 if (gre_ver > 1)
 358                         break;
 359
 360                 proto = hdr->protocol;
 361                 if (gre_ver) {
 362                         /* Version1 must be PPTP, and check the flags */
 363                         if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 364                                 break;
 365                 }
 366
 367                 offset += sizeof(struct gre_base_hdr);
 368
 369                 if (hdr->flags & GRE_CSUM)
 370                         offset += sizeof(((struct gre_full_hdr *)0)->csum) +
 371                                   sizeof(((struct gre_full_hdr *)0)->reserved1);
 372
 373                 if (hdr->flags & GRE_KEY) {
 374                         const __be32 *keyid;
 375                         __be32 _keyid;
 376
 377                         keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid),
 378                                                      data, hlen, &_keyid);
 379                         if (!keyid)
 380                                 goto out_bad;
 381
 382                         if (dissector_uses_key(flow_dissector,
 383                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 384                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 385                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 386                                                                       target_container);
 387                                 if (gre_ver == 0)
 388                                         key_keyid->keyid = *keyid;
 389                                 else
 390                                         key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 391                         }
 392                         offset += sizeof(((struct gre_full_hdr *)0)->key);
 393                 }
 394
 395                 if (hdr->flags & GRE_SEQ)
 396                         offset += sizeof(((struct pptp_gre_header *)0)->seq);
 397
 398                 if (gre_ver == 0) {
 399                         if (proto == htons(ETH_P_TEB)) {
 400                                 const struct ethhdr *eth;
 401                                 struct ethhdr _eth;
 402
 403                                 eth = __skb_header_pointer(skb, nhoff + offset,
 404                                                            sizeof(_eth),
 405                                                            data, hlen, &_eth);
 406                                 if (!eth)
 407                                         goto out_bad;
 408                                 proto = eth->h_proto;
 409                                 offset += sizeof(*eth);
 410
 411                                 /* Cap headers that we access via pointers at the
 412                                  * end of the Ethernet header as our maximum alignment
 413                                  * at that point is only 2 bytes.
 414                                  */
 415                                 if (NET_IP_ALIGN)
 416                                         hlen = (nhoff + offset);
 417                         }
 418                 } else { /* version 1, must be PPTP */
 419                         u8 _ppp_hdr[PPP_HDRLEN];
 420                         u8 *ppp_hdr;
 421
 422                         if (hdr->flags & GRE_ACK)
 423                                 offset += sizeof(((struct pptp_gre_header *)0)->ack);
 424
 425                         ppp_hdr = skb_header_pointer(skb, nhoff + offset,
 426                                                      sizeof(_ppp_hdr), _ppp_hdr);
 427                         if (!ppp_hdr)
 428                                 goto out_bad;
 429
 430                         switch (PPP_PROTOCOL(ppp_hdr)) {
 431                         case PPP_IP:
 432                                 proto = htons(ETH_P_IP);
 433                                 break;
 434                         case PPP_IPV6:
 435                                 proto = htons(ETH_P_IPV6);
 436                                 break;
 437                         default:
 438                                 /* Could probably catch some more like MPLS */
 439                                 break;
 440                         }
 441
 442                         offset += PPP_HDRLEN;
 443                 }
 444
 445                 nhoff += offset;
 446                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 447                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 448                         goto out_good;
 449
 450                 goto again;
 451         }
 452         case NEXTHDR_HOP:
 453         case NEXTHDR_ROUTING:
 454         case NEXTHDR_DEST: {
 455                 u8 _opthdr[2], *opthdr;
 456
 457                 if (proto != htons(ETH_P_IPV6))
 458                         break;
 459
 460                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 461                                               data, hlen, &_opthdr);
 462                 if (!opthdr)
 463                         goto out_bad;
 464
 465                 ip_proto = opthdr[0];
 466                 nhoff += (opthdr[1] + 1) << 3;
 467
 468                 goto ip_proto_again;
 469         }
 470         case NEXTHDR_FRAGMENT: {
 471                 struct frag_hdr _fh, *fh;
 472
 473                 if (proto != htons(ETH_P_IPV6))
 474                         break;
 475
 476                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 477                                           data, hlen, &_fh);
 478
 479                 if (!fh)
 480                         goto out_bad;
 481
 482                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 483
 484                 nhoff += sizeof(_fh);
 485                 ip_proto = fh->nexthdr;
 486
 487                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 488                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 489                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
 490                                 goto ip_proto_again;
 491                 }
 492                 goto out_good;
 493         }
 494         case IPPROTO_IPIP:
 495                 proto = htons(ETH_P_IP);
 496
 497                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 498                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 499                         goto out_good;
 500
 501                 goto ip;
 502         case IPPROTO_IPV6:
 503                 proto = htons(ETH_P_IPV6);
 504
 505                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 506                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 507                         goto out_good;
 508
 509                 goto ipv6;
 510         case IPPROTO_MPLS:
 511                 proto = htons(ETH_P_MPLS_UC);
 512                 goto mpls;
 513         default:
 514                 break;
 515         }
 516
 517         if (dissector_uses_key(flow_dissector,
 518                                FLOW_DISSECTOR_KEY_PORTS)) {
 519                 key_ports = skb_flow_dissector_target(flow_dissector,
 520                                                       FLOW_DISSECTOR_KEY_PORTS,
 521                                                       target_container);
 522                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 523                                                         data, hlen);
 524         }
 525
 526 out_good:
 527         ret = true;
 528
 529 out_bad:
 530         key_basic->n_proto = proto;
 531         key_basic->ip_proto = ip_proto;
 532         key_control->thoff = (u16)nhoff;
 533
 534         return ret;
 535 }
 536 EXPORT_SYMBOL(__skb_flow_dissect);
 537
 538 static u32 hashrnd __read_mostly;
 539 static __always_inline void __flow_hash_secret_init(void)
 540 {
 541         net_get_random_once(&hashrnd, sizeof(hashrnd));
 542 }
 543
 544 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 545                                              u32 keyval)
 546 {
 547         return jhash2(words, length, keyval);
 548 }
 549
 550 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
 551 {
 552         const void *p = flow;
 553
 554         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 555         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
 556 }
 557
 558 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 559 {
 560         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 561         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 562         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 563                      sizeof(*flow) - sizeof(flow->addrs));
 564
 565         switch (flow->control.addr_type) {
 566         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 567                 diff -= sizeof(flow->addrs.v4addrs);
 568                 break;
 569         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 570                 diff -= sizeof(flow->addrs.v6addrs);
 571                 break;
 572         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 573                 diff -= sizeof(flow->addrs.tipcaddrs);
 574                 break;
 575         }
 576         return (sizeof(*flow) - diff) / sizeof(u32);
 577 }
 578
 579 __be32 flow_get_u32_src(const struct flow_keys *flow)
 580 {
 581         switch (flow->control.addr_type) {
 582         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 583                 return flow->addrs.v4addrs.src;
 584         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 585                 return (__force __be32)ipv6_addr_hash(
 586                         &flow->addrs.v6addrs.src);
 587         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 588                 return flow->addrs.tipcaddrs.srcnode;
 589         default:
 590                 return 0;
 591         }
 592 }
 593 EXPORT_SYMBOL(flow_get_u32_src);
 594
 595 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 596 {
 597         switch (flow->control.addr_type) {
 598         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 599                 return flow->addrs.v4addrs.dst;
 600         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 601                 return (__force __be32)ipv6_addr_hash(
 602                         &flow->addrs.v6addrs.dst);
 603         default:
 604                 return 0;
 605         }
 606 }
 607 EXPORT_SYMBOL(flow_get_u32_dst);
 608
 609 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 610 {
 611         int addr_diff, i;
 612
 613         switch (keys->control.addr_type) {
 614         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 615                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 616                             (__force u32)keys->addrs.v4addrs.src;
 617                 if ((addr_diff < 0) ||
 618                     (addr_diff == 0 &&
 619                      ((__force u16)keys->ports.dst <
 620                       (__force u16)keys->ports.src))) {
 621                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 622                         swap(keys->ports.src, keys->ports.dst);
 623                 }
 624                 break;
 625         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 626                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 627                                    &keys->addrs.v6addrs.src,
 628                                    sizeof(keys->addrs.v6addrs.dst));
 629                 if ((addr_diff < 0) ||
 630                     (addr_diff == 0 &&
 631                      ((__force u16)keys->ports.dst <
 632                       (__force u16)keys->ports.src))) {
 633                         for (i = 0; i < 4; i++)
 634                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 635                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 636                         swap(keys->ports.src, keys->ports.dst);
 637                 }
 638                 break;
 639         }
 640 }
 641
 642 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 643 {
 644         u32 hash;
 645
 646         __flow_hash_consistentify(keys);
 647
 648         hash = __flow_hash_words(flow_keys_hash_start(keys),
 649                                  flow_keys_hash_length(keys), keyval);
 650         if (!hash)
 651                 hash = 1;
 652
 653         return hash;
 654 }
 655
 656 u32 flow_hash_from_keys(struct flow_keys *keys)
 657 {
 658         __flow_hash_secret_init();
 659         return __flow_hash_from_keys(keys, hashrnd);
 660 }
 661 EXPORT_SYMBOL(flow_hash_from_keys);
 662
 663 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 664                                   struct flow_keys *keys, u32 keyval)
 665 {
 666         skb_flow_dissect_flow_keys(skb, keys,
 667                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 668
 669         return __flow_hash_from_keys(keys, keyval);
 670 }
 671
 672 struct _flow_keys_digest_data {
 673         __be16  n_proto;
 674         u8      ip_proto;
 675         u8      padding;
 676         __be32  ports;
 677         __be32  src;
 678         __be32  dst;
 679 };
 680
 681 void make_flow_keys_digest(struct flow_keys_digest *digest,
 682                            const struct flow_keys *flow)
 683 {
 684         struct _flow_keys_digest_data *data =
 685             (struct _flow_keys_digest_data *)digest;
 686
 687         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 688
 689         memset(digest, 0, sizeof(*digest));
 690
 691         data->n_proto = flow->basic.n_proto;
 692         data->ip_proto = flow->basic.ip_proto;
 693         data->ports = flow->ports.ports;
 694         data->src = flow->addrs.v4addrs.src;
 695         data->dst = flow->addrs.v4addrs.dst;
 696 }
 697 EXPORT_SYMBOL(make_flow_keys_digest);
 698
 699 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
 700
 701 u32 __skb_get_hash_symmetric(struct sk_buff *skb)
 702 {
 703         struct flow_keys keys;
 704
 705         __flow_hash_secret_init();
 706
 707         memset(&keys, 0, sizeof(keys));
 708         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
 709                            NULL, 0, 0, 0,
 710                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 711
 712         return __flow_hash_from_keys(&keys, hashrnd);
 713 }
 714 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
 715
 716 /**
 717  * __skb_get_hash: calculate a flow hash
 718  * @skb: sk_buff to calculate flow hash from
 719  *
 720  * This function calculates a flow hash based on src/dst addresses
 721  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 722  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 723  * if hash is a canonical 4-tuple hash over transport ports.
 724  */
 725 void __skb_get_hash(struct sk_buff *skb)
 726 {
 727         struct flow_keys keys;
 728
 729         __flow_hash_secret_init();
 730
 731         __skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd),
 732                           flow_keys_have_l4(&keys));
 733 }
 734 EXPORT_SYMBOL(__skb_get_hash);
 735
 736 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 737 {
 738         struct flow_keys keys;
 739
 740         return ___skb_get_hash(skb, &keys, perturb);
 741 }
 742 EXPORT_SYMBOL(skb_get_hash_perturb);
 743
 744 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 745 {
 746         struct flow_keys keys;
 747
 748         memset(&keys, 0, sizeof(keys));
 749
 750         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 751                sizeof(keys.addrs.v6addrs.src));
 752         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 753                sizeof(keys.addrs.v6addrs.dst));
 754         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 755         keys.ports.src = fl6->fl6_sport;
 756         keys.ports.dst = fl6->fl6_dport;
 757         keys.keyid.keyid = fl6->fl6_gre_key;
 758         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 759         keys.basic.ip_proto = fl6->flowi6_proto;
 760
 761         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 762                           flow_keys_have_l4(&keys));
 763
 764         return skb->hash;
 765 }
 766 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 767
 768 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 769 {
 770         struct flow_keys keys;
 771
 772         memset(&keys, 0, sizeof(keys));
 773
 774         keys.addrs.v4addrs.src = fl4->saddr;
 775         keys.addrs.v4addrs.dst = fl4->daddr;
 776         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 777         keys.ports.src = fl4->fl4_sport;
 778         keys.ports.dst = fl4->fl4_dport;
 779         keys.keyid.keyid = fl4->fl4_gre_key;
 780         keys.basic.ip_proto = fl4->flowi4_proto;
 781
 782         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 783                           flow_keys_have_l4(&keys));
 784
 785         return skb->hash;
 786 }
 787 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 788
 789 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 790                    const struct flow_keys *keys, int hlen)
 791 {
 792         u32 poff = keys->control.thoff;
 793
 794         /* skip L4 headers for fragments after the first */
 795         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
 796             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
 797                 return poff;
 798
 799         switch (keys->basic.ip_proto) {
 800         case IPPROTO_TCP: {
 801                 /* access doff as u8 to avoid unaligned access */
 802                 const u8 *doff;
 803                 u8 _doff;
 804
 805                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 806                                             data, hlen, &_doff);
 807                 if (!doff)
 808                         return poff;
 809
 810                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 811                 break;
 812         }
 813         case IPPROTO_UDP:
 814         case IPPROTO_UDPLITE:
 815                 poff += sizeof(struct udphdr);
 816                 break;
 817         /* For the rest, we do not really care about header
 818          * extensions at this point for now.
 819          */
 820         case IPPROTO_ICMP:
 821                 poff += sizeof(struct icmphdr);
 822                 break;
 823         case IPPROTO_ICMPV6:
 824                 poff += sizeof(struct icmp6hdr);
 825                 break;
 826         case IPPROTO_IGMP:
 827                 poff += sizeof(struct igmphdr);
 828                 break;
 829         case IPPROTO_DCCP:
 830                 poff += sizeof(struct dccp_hdr);
 831                 break;
 832         case IPPROTO_SCTP:
 833                 poff += sizeof(struct sctphdr);
 834                 break;
 835         }
 836
 837         return poff;
 838 }
 839
 840 /**
 841  * skb_get_poff - get the offset to the payload
 842  * @skb: sk_buff to get the payload offset from
 843  *
 844  * The function will get the offset to the payload as far as it could
 845  * be dissected.  The main user is currently BPF, so that we can dynamically
 846  * truncate packets without needing to push actual payload to the user
 847  * space and can analyze headers only, instead.
 848  */
 849 u32 skb_get_poff(const struct sk_buff *skb)
 850 {
 851         struct flow_keys keys;
 852
 853         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 854                 return 0;
 855
 856         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 857 }
 858
 859 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 860 {
 861         memset(keys, 0, sizeof(*keys));
 862
 863         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 864             sizeof(keys->addrs.v6addrs.src));
 865         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 866             sizeof(keys->addrs.v6addrs.dst));
 867         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 868         keys->ports.src = fl6->fl6_sport;
 869         keys->ports.dst = fl6->fl6_dport;
 870         keys->keyid.keyid = fl6->fl6_gre_key;
 871         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 872         keys->basic.ip_proto = fl6->flowi6_proto;
 873
 874         return flow_hash_from_keys(keys);
 875 }
 876 EXPORT_SYMBOL(__get_hash_from_flowi6);
 877
 878 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 879 {
 880         memset(keys, 0, sizeof(*keys));
 881
 882         keys->addrs.v4addrs.src = fl4->saddr;
 883         keys->addrs.v4addrs.dst = fl4->daddr;
 884         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 885         keys->ports.src = fl4->fl4_sport;
 886         keys->ports.dst = fl4->fl4_dport;
 887         keys->keyid.keyid = fl4->fl4_gre_key;
 888         keys->basic.ip_proto = fl4->flowi4_proto;
 889
 890         return flow_hash_from_keys(keys);
 891 }
 892 EXPORT_SYMBOL(__get_hash_from_flowi4);
 893
 894 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 895         {
 896                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 897                 .offset = offsetof(struct flow_keys, control),
 898         },
 899         {
 900                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 901                 .offset = offsetof(struct flow_keys, basic),
 902         },
 903         {
 904                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 905                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 906         },
 907         {
 908                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 909                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 910         },
 911         {
 912                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 913                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 914         },
 915         {
 916                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 917                 .offset = offsetof(struct flow_keys, ports),
 918         },
 919         {
 920                 .key_id = FLOW_DISSECTOR_KEY_VLANID,
 921                 .offset = offsetof(struct flow_keys, tags),
 922         },
 923         {
 924                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 925                 .offset = offsetof(struct flow_keys, tags),
 926         },
 927         {
 928                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 929                 .offset = offsetof(struct flow_keys, keyid),
 930         },
 931 };
 932
 933 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
 934         {
 935                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 936                 .offset = offsetof(struct flow_keys, control),
 937         },
 938         {
 939                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 940                 .offset = offsetof(struct flow_keys, basic),
 941         },
 942         {
 943                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 944                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 945         },
 946         {
 947                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 948                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 949         },
 950         {
 951                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 952                 .offset = offsetof(struct flow_keys, ports),
 953         },
 954 };
 955
 956 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 957         {
 958                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 959                 .offset = offsetof(struct flow_keys, control),
 960         },
 961         {
 962                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 963                 .offset = offsetof(struct flow_keys, basic),
 964         },
 965 };
 966
 967 struct flow_dissector flow_keys_dissector __read_mostly;
 968 EXPORT_SYMBOL(flow_keys_dissector);
 969
 970 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 971
 972 static int __init init_default_flow_dissectors(void)
 973 {
 974         skb_flow_dissector_init(&flow_keys_dissector,
 975                                 flow_keys_dissector_keys,
 976                                 ARRAY_SIZE(flow_keys_dissector_keys));
 977         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
 978                                 flow_keys_dissector_symmetric_keys,
 979                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
 980         skb_flow_dissector_init(&flow_keys_buf_dissector,
 981                                 flow_keys_buf_dissector_keys,
 982                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
 983         return 0;
 984 }
 985
 986 late_initcall_sync(init_default_flow_dissectors);