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_be16 - extract be16 entity
  62  * @skb: sk_buff to extract from
  63  * @poff: offset to extract at
  64  * @data: raw buffer pointer to the packet
  65  * @hlen: packet header length
  66  *
  67  * The function will try to retrieve a be32 entity at
  68  * offset poff
  69  */
  70 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
  71                                 void *data, int hlen)
  72 {
  73         __be16 *u, _u;
  74
  75         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
  76         if (u)
  77                 return *u;
  78
  79         return 0;
  80 }
  81
  82 /**
  83  * __skb_flow_get_ports - extract the upper layer ports and return them
  84  * @skb: sk_buff to extract the ports from
  85  * @thoff: transport header offset
  86  * @ip_proto: protocol for which to get port offset
  87  * @data: raw buffer pointer to the packet, if NULL use skb->data
  88  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  89  *
  90  * The function will try to retrieve the ports at offset thoff + poff where poff
  91  * is the protocol port offset returned from proto_ports_offset
  92  */
  93 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  94                             void *data, int hlen)
  95 {
  96         int poff = proto_ports_offset(ip_proto);
  97
  98         if (!data) {
  99                 data = skb->data;
 100                 hlen = skb_headlen(skb);
 101         }
 102
 103         if (poff >= 0) {
 104                 __be32 *ports, _ports;
 105
 106                 ports = __skb_header_pointer(skb, thoff + poff,
 107                                              sizeof(_ports), data, hlen, &_ports);
 108                 if (ports)
 109                         return *ports;
 110         }
 111
 112         return 0;
 113 }
 114 EXPORT_SYMBOL(__skb_flow_get_ports);
 115
 116 /**
 117  * __skb_flow_dissect - extract the flow_keys struct and return it
 118  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 119  * @flow_dissector: list of keys to dissect
 120  * @target_container: target structure to put dissected values into
 121  * @data: raw buffer pointer to the packet, if NULL use skb->data
 122  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 123  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 124  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 125  *
 126  * The function will try to retrieve individual keys into target specified
 127  * by flow_dissector from either the skbuff or a raw buffer specified by the
 128  * rest parameters.
 129  *
 130  * Caller must take care of zeroing target container memory.
 131  */
 132 bool __skb_flow_dissect(const struct sk_buff *skb,
 133                         struct flow_dissector *flow_dissector,
 134                         void *target_container,
 135                         void *data, __be16 proto, int nhoff, int hlen,
 136                         unsigned int flags)
 137 {
 138         struct flow_dissector_key_control *key_control;
 139         struct flow_dissector_key_basic *key_basic;
 140         struct flow_dissector_key_addrs *key_addrs;
 141         struct flow_dissector_key_ports *key_ports;
 142         struct flow_dissector_key_icmp *key_icmp;
 143         struct flow_dissector_key_tags *key_tags;
 144         struct flow_dissector_key_vlan *key_vlan;
 145         struct flow_dissector_key_keyid *key_keyid;
 146         bool skip_vlan = false;
 147         u8 ip_proto = 0;
 148         bool ret;
 149
 150         if (!data) {
 151                 data = skb->data;
 152                 proto = skb_vlan_tag_present(skb) ?
 153                          skb->vlan_proto : skb->protocol;
 154                 nhoff = skb_network_offset(skb);
 155                 hlen = skb_headlen(skb);
 156         }
 157
 158         /* It is ensured by skb_flow_dissector_init() that control key will
 159          * be always present.
 160          */
 161         key_control = skb_flow_dissector_target(flow_dissector,
 162                                                 FLOW_DISSECTOR_KEY_CONTROL,
 163                                                 target_container);
 164
 165         /* It is ensured by skb_flow_dissector_init() that basic key will
 166          * be always present.
 167          */
 168         key_basic = skb_flow_dissector_target(flow_dissector,
 169                                               FLOW_DISSECTOR_KEY_BASIC,
 170                                               target_container);
 171
 172         if (dissector_uses_key(flow_dissector,
 173                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 174                 struct ethhdr *eth = eth_hdr(skb);
 175                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 176
 177                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 178                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 179                                                           target_container);
 180                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 181         }
 182
 183 again:
 184         switch (proto) {
 185         case htons(ETH_P_IP): {
 186                 const struct iphdr *iph;
 187                 struct iphdr _iph;
 188 ip:
 189                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 190                 if (!iph || iph->ihl < 5)
 191                         goto out_bad;
 192                 nhoff += iph->ihl * 4;
 193
 194                 ip_proto = iph->protocol;
 195
 196                 if (dissector_uses_key(flow_dissector,
 197                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 198                         key_addrs = skb_flow_dissector_target(flow_dissector,
 199                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 200                                                               target_container);
 201
 202                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 203                                sizeof(key_addrs->v4addrs));
 204                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 205                 }
 206
 207                 if (ip_is_fragment(iph)) {
 208                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 209
 210                         if (iph->frag_off & htons(IP_OFFSET)) {
 211                                 goto out_good;
 212                         } else {
 213                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 214                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 215                                         goto out_good;
 216                         }
 217                 }
 218
 219                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 220                         goto out_good;
 221
 222                 break;
 223         }
 224         case htons(ETH_P_IPV6): {
 225                 const struct ipv6hdr *iph;
 226                 struct ipv6hdr _iph;
 227
 228 ipv6:
 229                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 230                 if (!iph)
 231                         goto out_bad;
 232
 233                 ip_proto = iph->nexthdr;
 234                 nhoff += sizeof(struct ipv6hdr);
 235
 236                 if (dissector_uses_key(flow_dissector,
 237                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 238                         key_addrs = skb_flow_dissector_target(flow_dissector,
 239                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 240                                                               target_container);
 241
 242                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 243                                sizeof(key_addrs->v6addrs));
 244                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 245                 }
 246
 247                 if ((dissector_uses_key(flow_dissector,
 248                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 249                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 250                     ip6_flowlabel(iph)) {
 251                         __be32 flow_label = ip6_flowlabel(iph);
 252
 253                         if (dissector_uses_key(flow_dissector,
 254                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 255                                 key_tags = skb_flow_dissector_target(flow_dissector,
 256                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 257                                                                      target_container);
 258                                 key_tags->flow_label = ntohl(flow_label);
 259                         }
 260                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 261                                 goto out_good;
 262                 }
 263
 264                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 265                         goto out_good;
 266
 267                 break;
 268         }
 269         case htons(ETH_P_8021AD):
 270         case htons(ETH_P_8021Q): {
 271                 const struct vlan_hdr *vlan;
 272                 struct vlan_hdr _vlan;
 273                 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
 274
 275                 if (vlan_tag_present)
 276                         proto = skb->protocol;
 277
 278                 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
 279                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 280                                                     data, hlen, &_vlan);
 281                         if (!vlan)
 282                                 goto out_bad;
 283                         proto = vlan->h_vlan_encapsulated_proto;
 284                         nhoff += sizeof(*vlan);
 285                         if (skip_vlan)
 286                                 goto again;
 287                 }
 288
 289                 skip_vlan = true;
 290                 if (dissector_uses_key(flow_dissector,
 291                                        FLOW_DISSECTOR_KEY_VLAN)) {
 292                         key_vlan = skb_flow_dissector_target(flow_dissector,
 293                                                              FLOW_DISSECTOR_KEY_VLAN,
 294                                                              target_container);
 295
 296                         if (vlan_tag_present) {
 297                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 298                                 key_vlan->vlan_priority =
 299                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 300                         } else {
 301                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 302                                         VLAN_VID_MASK;
 303                                 key_vlan->vlan_priority =
 304                                         (ntohs(vlan->h_vlan_TCI) &
 305                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 306                         }
 307                 }
 308
 309                 goto again;
 310         }
 311         case htons(ETH_P_PPP_SES): {
 312                 struct {
 313                         struct pppoe_hdr hdr;
 314                         __be16 proto;
 315                 } *hdr, _hdr;
 316                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 317                 if (!hdr)
 318                         goto out_bad;
 319                 proto = hdr->proto;
 320                 nhoff += PPPOE_SES_HLEN;
 321                 switch (proto) {
 322                 case htons(PPP_IP):
 323                         goto ip;
 324                 case htons(PPP_IPV6):
 325                         goto ipv6;
 326                 default:
 327                         goto out_bad;
 328                 }
 329         }
 330         case htons(ETH_P_TIPC): {
 331                 struct {
 332                         __be32 pre[3];
 333                         __be32 srcnode;
 334                 } *hdr, _hdr;
 335                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 336                 if (!hdr)
 337                         goto out_bad;
 338
 339                 if (dissector_uses_key(flow_dissector,
 340                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 341                         key_addrs = skb_flow_dissector_target(flow_dissector,
 342                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 343                                                               target_container);
 344                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 345                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 346                 }
 347                 goto out_good;
 348         }
 349
 350         case htons(ETH_P_MPLS_UC):
 351         case htons(ETH_P_MPLS_MC): {
 352                 struct mpls_label *hdr, _hdr[2];
 353 mpls:
 354                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 355                                            hlen, &_hdr);
 356                 if (!hdr)
 357                         goto out_bad;
 358
 359                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 360                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 361                         if (dissector_uses_key(flow_dissector,
 362                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 363                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 364                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 365                                                                       target_container);
 366                                 key_keyid->keyid = hdr[1].entry &
 367                                         htonl(MPLS_LS_LABEL_MASK);
 368                         }
 369
 370                         goto out_good;
 371                 }
 372
 373                 goto out_good;
 374         }
 375
 376         case htons(ETH_P_FCOE):
 377                 if ((hlen - nhoff) < FCOE_HEADER_LEN)
 378                         goto out_bad;
 379
 380                 nhoff += FCOE_HEADER_LEN;
 381                 goto out_good;
 382         default:
 383                 goto out_bad;
 384         }
 385
 386 ip_proto_again:
 387         switch (ip_proto) {
 388         case IPPROTO_GRE: {
 389                 struct gre_base_hdr *hdr, _hdr;
 390                 u16 gre_ver;
 391                 int offset = 0;
 392
 393                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 394                 if (!hdr)
 395                         goto out_bad;
 396
 397                 /* Only look inside GRE without routing */
 398                 if (hdr->flags & GRE_ROUTING)
 399                         break;
 400
 401                 /* Only look inside GRE for version 0 and 1 */
 402                 gre_ver = ntohs(hdr->flags & GRE_VERSION);
 403                 if (gre_ver > 1)
 404                         break;
 405
 406                 proto = hdr->protocol;
 407                 if (gre_ver) {
 408                         /* Version1 must be PPTP, and check the flags */
 409                         if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 410                                 break;
 411                 }
 412
 413                 offset += sizeof(struct gre_base_hdr);
 414
 415                 if (hdr->flags & GRE_CSUM)
 416                         offset += sizeof(((struct gre_full_hdr *)0)->csum) +
 417                                   sizeof(((struct gre_full_hdr *)0)->reserved1);
 418
 419                 if (hdr->flags & GRE_KEY) {
 420                         const __be32 *keyid;
 421                         __be32 _keyid;
 422
 423                         keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid),
 424                                                      data, hlen, &_keyid);
 425                         if (!keyid)
 426                                 goto out_bad;
 427
 428                         if (dissector_uses_key(flow_dissector,
 429                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 430                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 431                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 432                                                                       target_container);
 433                                 if (gre_ver == 0)
 434                                         key_keyid->keyid = *keyid;
 435                                 else
 436                                         key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 437                         }
 438                         offset += sizeof(((struct gre_full_hdr *)0)->key);
 439                 }
 440
 441                 if (hdr->flags & GRE_SEQ)
 442                         offset += sizeof(((struct pptp_gre_header *)0)->seq);
 443
 444                 if (gre_ver == 0) {
 445                         if (proto == htons(ETH_P_TEB)) {
 446                                 const struct ethhdr *eth;
 447                                 struct ethhdr _eth;
 448
 449                                 eth = __skb_header_pointer(skb, nhoff + offset,
 450                                                            sizeof(_eth),
 451                                                            data, hlen, &_eth);
 452                                 if (!eth)
 453                                         goto out_bad;
 454                                 proto = eth->h_proto;
 455                                 offset += sizeof(*eth);
 456
 457                                 /* Cap headers that we access via pointers at the
 458                                  * end of the Ethernet header as our maximum alignment
 459                                  * at that point is only 2 bytes.
 460                                  */
 461                                 if (NET_IP_ALIGN)
 462                                         hlen = (nhoff + offset);
 463                         }
 464                 } else { /* version 1, must be PPTP */
 465                         u8 _ppp_hdr[PPP_HDRLEN];
 466                         u8 *ppp_hdr;
 467
 468                         if (hdr->flags & GRE_ACK)
 469                                 offset += sizeof(((struct pptp_gre_header *)0)->ack);
 470
 471                         ppp_hdr = __skb_header_pointer(skb, nhoff + offset,
 472                                                      sizeof(_ppp_hdr),
 473                                                      data, hlen, _ppp_hdr);
 474                         if (!ppp_hdr)
 475                                 goto out_bad;
 476
 477                         switch (PPP_PROTOCOL(ppp_hdr)) {
 478                         case PPP_IP:
 479                                 proto = htons(ETH_P_IP);
 480                                 break;
 481                         case PPP_IPV6:
 482                                 proto = htons(ETH_P_IPV6);
 483                                 break;
 484                         default:
 485                                 /* Could probably catch some more like MPLS */
 486                                 break;
 487                         }
 488
 489                         offset += PPP_HDRLEN;
 490                 }
 491
 492                 nhoff += offset;
 493                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 494                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 495                         goto out_good;
 496
 497                 goto again;
 498         }
 499         case NEXTHDR_HOP:
 500         case NEXTHDR_ROUTING:
 501         case NEXTHDR_DEST: {
 502                 u8 _opthdr[2], *opthdr;
 503
 504                 if (proto != htons(ETH_P_IPV6))
 505                         break;
 506
 507                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 508                                               data, hlen, &_opthdr);
 509                 if (!opthdr)
 510                         goto out_bad;
 511
 512                 ip_proto = opthdr[0];
 513                 nhoff += (opthdr[1] + 1) << 3;
 514
 515                 goto ip_proto_again;
 516         }
 517         case NEXTHDR_FRAGMENT: {
 518                 struct frag_hdr _fh, *fh;
 519
 520                 if (proto != htons(ETH_P_IPV6))
 521                         break;
 522
 523                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 524                                           data, hlen, &_fh);
 525
 526                 if (!fh)
 527                         goto out_bad;
 528
 529                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 530
 531                 nhoff += sizeof(_fh);
 532                 ip_proto = fh->nexthdr;
 533
 534                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 535                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 536                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
 537                                 goto ip_proto_again;
 538                 }
 539                 goto out_good;
 540         }
 541         case IPPROTO_IPIP:
 542                 proto = htons(ETH_P_IP);
 543
 544                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 545                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 546                         goto out_good;
 547
 548                 goto ip;
 549         case IPPROTO_IPV6:
 550                 proto = htons(ETH_P_IPV6);
 551
 552                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 553                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 554                         goto out_good;
 555
 556                 goto ipv6;
 557         case IPPROTO_MPLS:
 558                 proto = htons(ETH_P_MPLS_UC);
 559                 goto mpls;
 560         default:
 561                 break;
 562         }
 563
 564         if (dissector_uses_key(flow_dissector,
 565                                FLOW_DISSECTOR_KEY_PORTS)) {
 566                 key_ports = skb_flow_dissector_target(flow_dissector,
 567                                                       FLOW_DISSECTOR_KEY_PORTS,
 568                                                       target_container);
 569                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 570                                                         data, hlen);
 571         }
 572
 573         if (dissector_uses_key(flow_dissector,
 574                                FLOW_DISSECTOR_KEY_ICMP)) {
 575                 key_icmp = skb_flow_dissector_target(flow_dissector,
 576                                                      FLOW_DISSECTOR_KEY_ICMP,
 577                                                      target_container);
 578                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
 579         }
 580
 581 out_good:
 582         ret = true;
 583
 584         key_control->thoff = (u16)nhoff;
 585 out:
 586         key_basic->n_proto = proto;
 587         key_basic->ip_proto = ip_proto;
 588
 589         return ret;
 590
 591 out_bad:
 592         ret = false;
 593         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
 594         goto out;
 595 }
 596 EXPORT_SYMBOL(__skb_flow_dissect);
 597
 598 static u32 hashrnd __read_mostly;
 599 static __always_inline void __flow_hash_secret_init(void)
 600 {
 601         net_get_random_once(&hashrnd, sizeof(hashrnd));
 602 }
 603
 604 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 605                                              u32 keyval)
 606 {
 607         return jhash2(words, length, keyval);
 608 }
 609
 610 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
 611 {
 612         const void *p = flow;
 613
 614         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 615         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
 616 }
 617
 618 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 619 {
 620         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 621         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 622         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 623                      sizeof(*flow) - sizeof(flow->addrs));
 624
 625         switch (flow->control.addr_type) {
 626         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 627                 diff -= sizeof(flow->addrs.v4addrs);
 628                 break;
 629         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 630                 diff -= sizeof(flow->addrs.v6addrs);
 631                 break;
 632         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 633                 diff -= sizeof(flow->addrs.tipcaddrs);
 634                 break;
 635         }
 636         return (sizeof(*flow) - diff) / sizeof(u32);
 637 }
 638
 639 __be32 flow_get_u32_src(const struct flow_keys *flow)
 640 {
 641         switch (flow->control.addr_type) {
 642         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 643                 return flow->addrs.v4addrs.src;
 644         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 645                 return (__force __be32)ipv6_addr_hash(
 646                         &flow->addrs.v6addrs.src);
 647         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 648                 return flow->addrs.tipcaddrs.srcnode;
 649         default:
 650                 return 0;
 651         }
 652 }
 653 EXPORT_SYMBOL(flow_get_u32_src);
 654
 655 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 656 {
 657         switch (flow->control.addr_type) {
 658         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 659                 return flow->addrs.v4addrs.dst;
 660         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 661                 return (__force __be32)ipv6_addr_hash(
 662                         &flow->addrs.v6addrs.dst);
 663         default:
 664                 return 0;
 665         }
 666 }
 667 EXPORT_SYMBOL(flow_get_u32_dst);
 668
 669 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 670 {
 671         int addr_diff, i;
 672
 673         switch (keys->control.addr_type) {
 674         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 675                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 676                             (__force u32)keys->addrs.v4addrs.src;
 677                 if ((addr_diff < 0) ||
 678                     (addr_diff == 0 &&
 679                      ((__force u16)keys->ports.dst <
 680                       (__force u16)keys->ports.src))) {
 681                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 682                         swap(keys->ports.src, keys->ports.dst);
 683                 }
 684                 break;
 685         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 686                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 687                                    &keys->addrs.v6addrs.src,
 688                                    sizeof(keys->addrs.v6addrs.dst));
 689                 if ((addr_diff < 0) ||
 690                     (addr_diff == 0 &&
 691                      ((__force u16)keys->ports.dst <
 692                       (__force u16)keys->ports.src))) {
 693                         for (i = 0; i < 4; i++)
 694                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 695                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 696                         swap(keys->ports.src, keys->ports.dst);
 697                 }
 698                 break;
 699         }
 700 }
 701
 702 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 703 {
 704         u32 hash;
 705
 706         __flow_hash_consistentify(keys);
 707
 708         hash = __flow_hash_words(flow_keys_hash_start(keys),
 709                                  flow_keys_hash_length(keys), keyval);
 710         if (!hash)
 711                 hash = 1;
 712
 713         return hash;
 714 }
 715
 716 u32 flow_hash_from_keys(struct flow_keys *keys)
 717 {
 718         __flow_hash_secret_init();
 719         return __flow_hash_from_keys(keys, hashrnd);
 720 }
 721 EXPORT_SYMBOL(flow_hash_from_keys);
 722
 723 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 724                                   struct flow_keys *keys, u32 keyval)
 725 {
 726         skb_flow_dissect_flow_keys(skb, keys,
 727                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 728
 729         return __flow_hash_from_keys(keys, keyval);
 730 }
 731
 732 struct _flow_keys_digest_data {
 733         __be16  n_proto;
 734         u8      ip_proto;
 735         u8      padding;
 736         __be32  ports;
 737         __be32  src;
 738         __be32  dst;
 739 };
 740
 741 void make_flow_keys_digest(struct flow_keys_digest *digest,
 742                            const struct flow_keys *flow)
 743 {
 744         struct _flow_keys_digest_data *data =
 745             (struct _flow_keys_digest_data *)digest;
 746
 747         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 748
 749         memset(digest, 0, sizeof(*digest));
 750
 751         data->n_proto = flow->basic.n_proto;
 752         data->ip_proto = flow->basic.ip_proto;
 753         data->ports = flow->ports.ports;
 754         data->src = flow->addrs.v4addrs.src;
 755         data->dst = flow->addrs.v4addrs.dst;
 756 }
 757 EXPORT_SYMBOL(make_flow_keys_digest);
 758
 759 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
 760
 761 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
 762 {
 763         struct flow_keys keys;
 764
 765         __flow_hash_secret_init();
 766
 767         memset(&keys, 0, sizeof(keys));
 768         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
 769                            NULL, 0, 0, 0,
 770                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 771
 772         return __flow_hash_from_keys(&keys, hashrnd);
 773 }
 774 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
 775
 776 /**
 777  * __skb_get_hash: calculate a flow hash
 778  * @skb: sk_buff to calculate flow hash from
 779  *
 780  * This function calculates a flow hash based on src/dst addresses
 781  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 782  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 783  * if hash is a canonical 4-tuple hash over transport ports.
 784  */
 785 void __skb_get_hash(struct sk_buff *skb)
 786 {
 787         struct flow_keys keys;
 788         u32 hash;
 789
 790         __flow_hash_secret_init();
 791
 792         hash = ___skb_get_hash(skb, &keys, hashrnd);
 793
 794         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
 795 }
 796 EXPORT_SYMBOL(__skb_get_hash);
 797
 798 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 799 {
 800         struct flow_keys keys;
 801
 802         return ___skb_get_hash(skb, &keys, perturb);
 803 }
 804 EXPORT_SYMBOL(skb_get_hash_perturb);
 805
 806 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 807 {
 808         struct flow_keys keys;
 809
 810         memset(&keys, 0, sizeof(keys));
 811
 812         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 813                sizeof(keys.addrs.v6addrs.src));
 814         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 815                sizeof(keys.addrs.v6addrs.dst));
 816         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 817         keys.ports.src = fl6->fl6_sport;
 818         keys.ports.dst = fl6->fl6_dport;
 819         keys.keyid.keyid = fl6->fl6_gre_key;
 820         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 821         keys.basic.ip_proto = fl6->flowi6_proto;
 822
 823         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 824                           flow_keys_have_l4(&keys));
 825
 826         return skb->hash;
 827 }
 828 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 829
 830 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 831 {
 832         struct flow_keys keys;
 833
 834         memset(&keys, 0, sizeof(keys));
 835
 836         keys.addrs.v4addrs.src = fl4->saddr;
 837         keys.addrs.v4addrs.dst = fl4->daddr;
 838         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 839         keys.ports.src = fl4->fl4_sport;
 840         keys.ports.dst = fl4->fl4_dport;
 841         keys.keyid.keyid = fl4->fl4_gre_key;
 842         keys.basic.ip_proto = fl4->flowi4_proto;
 843
 844         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 845                           flow_keys_have_l4(&keys));
 846
 847         return skb->hash;
 848 }
 849 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 850
 851 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 852                    const struct flow_keys *keys, int hlen)
 853 {
 854         u32 poff = keys->control.thoff;
 855
 856         /* skip L4 headers for fragments after the first */
 857         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
 858             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
 859                 return poff;
 860
 861         switch (keys->basic.ip_proto) {
 862         case IPPROTO_TCP: {
 863                 /* access doff as u8 to avoid unaligned access */
 864                 const u8 *doff;
 865                 u8 _doff;
 866
 867                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 868                                             data, hlen, &_doff);
 869                 if (!doff)
 870                         return poff;
 871
 872                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 873                 break;
 874         }
 875         case IPPROTO_UDP:
 876         case IPPROTO_UDPLITE:
 877                 poff += sizeof(struct udphdr);
 878                 break;
 879         /* For the rest, we do not really care about header
 880          * extensions at this point for now.
 881          */
 882         case IPPROTO_ICMP:
 883                 poff += sizeof(struct icmphdr);
 884                 break;
 885         case IPPROTO_ICMPV6:
 886                 poff += sizeof(struct icmp6hdr);
 887                 break;
 888         case IPPROTO_IGMP:
 889                 poff += sizeof(struct igmphdr);
 890                 break;
 891         case IPPROTO_DCCP:
 892                 poff += sizeof(struct dccp_hdr);
 893                 break;
 894         case IPPROTO_SCTP:
 895                 poff += sizeof(struct sctphdr);
 896                 break;
 897         }
 898
 899         return poff;
 900 }
 901
 902 /**
 903  * skb_get_poff - get the offset to the payload
 904  * @skb: sk_buff to get the payload offset from
 905  *
 906  * The function will get the offset to the payload as far as it could
 907  * be dissected.  The main user is currently BPF, so that we can dynamically
 908  * truncate packets without needing to push actual payload to the user
 909  * space and can analyze headers only, instead.
 910  */
 911 u32 skb_get_poff(const struct sk_buff *skb)
 912 {
 913         struct flow_keys keys;
 914
 915         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 916                 return 0;
 917
 918         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 919 }
 920
 921 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 922 {
 923         memset(keys, 0, sizeof(*keys));
 924
 925         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 926             sizeof(keys->addrs.v6addrs.src));
 927         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 928             sizeof(keys->addrs.v6addrs.dst));
 929         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 930         keys->ports.src = fl6->fl6_sport;
 931         keys->ports.dst = fl6->fl6_dport;
 932         keys->keyid.keyid = fl6->fl6_gre_key;
 933         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 934         keys->basic.ip_proto = fl6->flowi6_proto;
 935
 936         return flow_hash_from_keys(keys);
 937 }
 938 EXPORT_SYMBOL(__get_hash_from_flowi6);
 939
 940 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 941 {
 942         memset(keys, 0, sizeof(*keys));
 943
 944         keys->addrs.v4addrs.src = fl4->saddr;
 945         keys->addrs.v4addrs.dst = fl4->daddr;
 946         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 947         keys->ports.src = fl4->fl4_sport;
 948         keys->ports.dst = fl4->fl4_dport;
 949         keys->keyid.keyid = fl4->fl4_gre_key;
 950         keys->basic.ip_proto = fl4->flowi4_proto;
 951
 952         return flow_hash_from_keys(keys);
 953 }
 954 EXPORT_SYMBOL(__get_hash_from_flowi4);
 955
 956 static const struct flow_dissector_key flow_keys_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                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 967                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 968         },
 969         {
 970                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 971                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 972         },
 973         {
 974                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 975                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 976         },
 977         {
 978                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 979                 .offset = offsetof(struct flow_keys, ports),
 980         },
 981         {
 982                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
 983                 .offset = offsetof(struct flow_keys, vlan),
 984         },
 985         {
 986                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 987                 .offset = offsetof(struct flow_keys, tags),
 988         },
 989         {
 990                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 991                 .offset = offsetof(struct flow_keys, keyid),
 992         },
 993 };
 994
 995 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
 996         {
 997                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 998                 .offset = offsetof(struct flow_keys, control),
 999         },
1000         {
1001                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1002                 .offset = offsetof(struct flow_keys, basic),
1003         },
1004         {
1005                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1006                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1007         },
1008         {
1009                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1010                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1011         },
1012         {
1013                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1014                 .offset = offsetof(struct flow_keys, ports),
1015         },
1016 };
1017
1018 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
1019         {
1020                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1021                 .offset = offsetof(struct flow_keys, control),
1022         },
1023         {
1024                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1025                 .offset = offsetof(struct flow_keys, basic),
1026         },
1027 };
1028
1029 struct flow_dissector flow_keys_dissector __read_mostly;
1030 EXPORT_SYMBOL(flow_keys_dissector);
1031
1032 struct flow_dissector flow_keys_buf_dissector __read_mostly;
1033
1034 static int __init init_default_flow_dissectors(void)
1035 {
1036         skb_flow_dissector_init(&flow_keys_dissector,
1037                                 flow_keys_dissector_keys,
1038                                 ARRAY_SIZE(flow_keys_dissector_keys));
1039         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1040                                 flow_keys_dissector_symmetric_keys,
1041                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1042         skb_flow_dissector_init(&flow_keys_buf_dissector,
1043                                 flow_keys_buf_dissector_keys,
1044                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1045         return 0;
1046 }
1047
1048 core_initcall(init_default_flow_dissectors);