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_vlan *key_vlan;
 122         struct flow_dissector_key_keyid *key_keyid;
 123         bool skip_vlan = false;
 124         u8 ip_proto = 0;
 125         bool ret;
 126
 127         if (!data) {
 128                 data = skb->data;
 129                 proto = skb_vlan_tag_present(skb) ?
 130                          skb->vlan_proto : skb->protocol;
 131                 nhoff = skb_network_offset(skb);
 132                 hlen = skb_headlen(skb);
 133         }
 134
 135         /* It is ensured by skb_flow_dissector_init() that control key will
 136          * be always present.
 137          */
 138         key_control = skb_flow_dissector_target(flow_dissector,
 139                                                 FLOW_DISSECTOR_KEY_CONTROL,
 140                                                 target_container);
 141
 142         /* It is ensured by skb_flow_dissector_init() that basic key will
 143          * be always present.
 144          */
 145         key_basic = skb_flow_dissector_target(flow_dissector,
 146                                               FLOW_DISSECTOR_KEY_BASIC,
 147                                               target_container);
 148
 149         if (dissector_uses_key(flow_dissector,
 150                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 151                 struct ethhdr *eth = eth_hdr(skb);
 152                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 153
 154                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 155                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 156                                                           target_container);
 157                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 158         }
 159
 160 again:
 161         switch (proto) {
 162         case htons(ETH_P_IP): {
 163                 const struct iphdr *iph;
 164                 struct iphdr _iph;
 165 ip:
 166                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 167                 if (!iph || iph->ihl < 5)
 168                         goto out_bad;
 169                 nhoff += iph->ihl * 4;
 170
 171                 ip_proto = iph->protocol;
 172
 173                 if (dissector_uses_key(flow_dissector,
 174                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 175                         key_addrs = skb_flow_dissector_target(flow_dissector,
 176                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 177                                                               target_container);
 178
 179                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 180                                sizeof(key_addrs->v4addrs));
 181                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 182                 }
 183
 184                 if (ip_is_fragment(iph)) {
 185                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 186
 187                         if (iph->frag_off & htons(IP_OFFSET)) {
 188                                 goto out_good;
 189                         } else {
 190                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 191                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 192                                         goto out_good;
 193                         }
 194                 }
 195
 196                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 197                         goto out_good;
 198
 199                 break;
 200         }
 201         case htons(ETH_P_IPV6): {
 202                 const struct ipv6hdr *iph;
 203                 struct ipv6hdr _iph;
 204
 205 ipv6:
 206                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 207                 if (!iph)
 208                         goto out_bad;
 209
 210                 ip_proto = iph->nexthdr;
 211                 nhoff += sizeof(struct ipv6hdr);
 212
 213                 if (dissector_uses_key(flow_dissector,
 214                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 215                         key_addrs = skb_flow_dissector_target(flow_dissector,
 216                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 217                                                               target_container);
 218
 219                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 220                                sizeof(key_addrs->v6addrs));
 221                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 222                 }
 223
 224                 if ((dissector_uses_key(flow_dissector,
 225                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 226                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 227                     ip6_flowlabel(iph)) {
 228                         __be32 flow_label = ip6_flowlabel(iph);
 229
 230                         if (dissector_uses_key(flow_dissector,
 231                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 232                                 key_tags = skb_flow_dissector_target(flow_dissector,
 233                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 234                                                                      target_container);
 235                                 key_tags->flow_label = ntohl(flow_label);
 236                         }
 237                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 238                                 goto out_good;
 239                 }
 240
 241                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 242                         goto out_good;
 243
 244                 break;
 245         }
 246         case htons(ETH_P_8021AD):
 247         case htons(ETH_P_8021Q): {
 248                 const struct vlan_hdr *vlan;
 249                 struct vlan_hdr _vlan;
 250                 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
 251
 252                 if (vlan_tag_present)
 253                         proto = skb->protocol;
 254
 255                 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
 256                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 257                                                     data, hlen, &_vlan);
 258                         if (!vlan)
 259                                 goto out_bad;
 260                         proto = vlan->h_vlan_encapsulated_proto;
 261                         nhoff += sizeof(*vlan);
 262                         if (skip_vlan)
 263                                 goto again;
 264                 }
 265
 266                 skip_vlan = true;
 267                 if (dissector_uses_key(flow_dissector,
 268                                        FLOW_DISSECTOR_KEY_VLAN)) {
 269                         key_vlan = skb_flow_dissector_target(flow_dissector,
 270                                                              FLOW_DISSECTOR_KEY_VLAN,
 271                                                              target_container);
 272
 273                         if (vlan_tag_present) {
 274                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 275                                 key_vlan->vlan_priority =
 276                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 277                         } else {
 278                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 279                                         VLAN_VID_MASK;
 280                                 key_vlan->vlan_priority =
 281                                         (ntohs(vlan->h_vlan_TCI) &
 282                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 283                         }
 284                 }
 285
 286                 goto again;
 287         }
 288         case htons(ETH_P_PPP_SES): {
 289                 struct {
 290                         struct pppoe_hdr hdr;
 291                         __be16 proto;
 292                 } *hdr, _hdr;
 293                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 294                 if (!hdr)
 295                         goto out_bad;
 296                 proto = hdr->proto;
 297                 nhoff += PPPOE_SES_HLEN;
 298                 switch (proto) {
 299                 case htons(PPP_IP):
 300                         goto ip;
 301                 case htons(PPP_IPV6):
 302                         goto ipv6;
 303                 default:
 304                         goto out_bad;
 305                 }
 306         }
 307         case htons(ETH_P_TIPC): {
 308                 struct {
 309                         __be32 pre[3];
 310                         __be32 srcnode;
 311                 } *hdr, _hdr;
 312                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 313                 if (!hdr)
 314                         goto out_bad;
 315
 316                 if (dissector_uses_key(flow_dissector,
 317                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 318                         key_addrs = skb_flow_dissector_target(flow_dissector,
 319                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 320                                                               target_container);
 321                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 322                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 323                 }
 324                 goto out_good;
 325         }
 326
 327         case htons(ETH_P_MPLS_UC):
 328         case htons(ETH_P_MPLS_MC): {
 329                 struct mpls_label *hdr, _hdr[2];
 330 mpls:
 331                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 332                                            hlen, &_hdr);
 333                 if (!hdr)
 334                         goto out_bad;
 335
 336                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 337                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 338                         if (dissector_uses_key(flow_dissector,
 339                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 340                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 341                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 342                                                                       target_container);
 343                                 key_keyid->keyid = hdr[1].entry &
 344                                         htonl(MPLS_LS_LABEL_MASK);
 345                         }
 346
 347                         goto out_good;
 348                 }
 349
 350                 goto out_good;
 351         }
 352
 353         case htons(ETH_P_FCOE):
 354                 if ((hlen - nhoff) < FCOE_HEADER_LEN)
 355                         goto out_bad;
 356
 357                 nhoff += FCOE_HEADER_LEN;
 358                 goto out_good;
 359         default:
 360                 goto out_bad;
 361         }
 362
 363 ip_proto_again:
 364         switch (ip_proto) {
 365         case IPPROTO_GRE: {
 366                 struct gre_base_hdr *hdr, _hdr;
 367                 u16 gre_ver;
 368                 int offset = 0;
 369
 370                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 371                 if (!hdr)
 372                         goto out_bad;
 373
 374                 /* Only look inside GRE without routing */
 375                 if (hdr->flags & GRE_ROUTING)
 376                         break;
 377
 378                 /* Only look inside GRE for version 0 and 1 */
 379                 gre_ver = ntohs(hdr->flags & GRE_VERSION);
 380                 if (gre_ver > 1)
 381                         break;
 382
 383                 proto = hdr->protocol;
 384                 if (gre_ver) {
 385                         /* Version1 must be PPTP, and check the flags */
 386                         if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 387                                 break;
 388                 }
 389
 390                 offset += sizeof(struct gre_base_hdr);
 391
 392                 if (hdr->flags & GRE_CSUM)
 393                         offset += sizeof(((struct gre_full_hdr *)0)->csum) +
 394                                   sizeof(((struct gre_full_hdr *)0)->reserved1);
 395
 396                 if (hdr->flags & GRE_KEY) {
 397                         const __be32 *keyid;
 398                         __be32 _keyid;
 399
 400                         keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid),
 401                                                      data, hlen, &_keyid);
 402                         if (!keyid)
 403                                 goto out_bad;
 404
 405                         if (dissector_uses_key(flow_dissector,
 406                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 407                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 408                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 409                                                                       target_container);
 410                                 if (gre_ver == 0)
 411                                         key_keyid->keyid = *keyid;
 412                                 else
 413                                         key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 414                         }
 415                         offset += sizeof(((struct gre_full_hdr *)0)->key);
 416                 }
 417
 418                 if (hdr->flags & GRE_SEQ)
 419                         offset += sizeof(((struct pptp_gre_header *)0)->seq);
 420
 421                 if (gre_ver == 0) {
 422                         if (proto == htons(ETH_P_TEB)) {
 423                                 const struct ethhdr *eth;
 424                                 struct ethhdr _eth;
 425
 426                                 eth = __skb_header_pointer(skb, nhoff + offset,
 427                                                            sizeof(_eth),
 428                                                            data, hlen, &_eth);
 429                                 if (!eth)
 430                                         goto out_bad;
 431                                 proto = eth->h_proto;
 432                                 offset += sizeof(*eth);
 433
 434                                 /* Cap headers that we access via pointers at the
 435                                  * end of the Ethernet header as our maximum alignment
 436                                  * at that point is only 2 bytes.
 437                                  */
 438                                 if (NET_IP_ALIGN)
 439                                         hlen = (nhoff + offset);
 440                         }
 441                 } else { /* version 1, must be PPTP */
 442                         u8 _ppp_hdr[PPP_HDRLEN];
 443                         u8 *ppp_hdr;
 444
 445                         if (hdr->flags & GRE_ACK)
 446                                 offset += sizeof(((struct pptp_gre_header *)0)->ack);
 447
 448                         ppp_hdr = __skb_header_pointer(skb, nhoff + offset,
 449                                                      sizeof(_ppp_hdr),
 450                                                      data, hlen, _ppp_hdr);
 451                         if (!ppp_hdr)
 452                                 goto out_bad;
 453
 454                         switch (PPP_PROTOCOL(ppp_hdr)) {
 455                         case PPP_IP:
 456                                 proto = htons(ETH_P_IP);
 457                                 break;
 458                         case PPP_IPV6:
 459                                 proto = htons(ETH_P_IPV6);
 460                                 break;
 461                         default:
 462                                 /* Could probably catch some more like MPLS */
 463                                 break;
 464                         }
 465
 466                         offset += PPP_HDRLEN;
 467                 }
 468
 469                 nhoff += offset;
 470                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 471                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 472                         goto out_good;
 473
 474                 goto again;
 475         }
 476         case NEXTHDR_HOP:
 477         case NEXTHDR_ROUTING:
 478         case NEXTHDR_DEST: {
 479                 u8 _opthdr[2], *opthdr;
 480
 481                 if (proto != htons(ETH_P_IPV6))
 482                         break;
 483
 484                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 485                                               data, hlen, &_opthdr);
 486                 if (!opthdr)
 487                         goto out_bad;
 488
 489                 ip_proto = opthdr[0];
 490                 nhoff += (opthdr[1] + 1) << 3;
 491
 492                 goto ip_proto_again;
 493         }
 494         case NEXTHDR_FRAGMENT: {
 495                 struct frag_hdr _fh, *fh;
 496
 497                 if (proto != htons(ETH_P_IPV6))
 498                         break;
 499
 500                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 501                                           data, hlen, &_fh);
 502
 503                 if (!fh)
 504                         goto out_bad;
 505
 506                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 507
 508                 nhoff += sizeof(_fh);
 509                 ip_proto = fh->nexthdr;
 510
 511                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 512                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 513                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
 514                                 goto ip_proto_again;
 515                 }
 516                 goto out_good;
 517         }
 518         case IPPROTO_IPIP:
 519                 proto = htons(ETH_P_IP);
 520
 521                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 522                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 523                         goto out_good;
 524
 525                 goto ip;
 526         case IPPROTO_IPV6:
 527                 proto = htons(ETH_P_IPV6);
 528
 529                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 530                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 531                         goto out_good;
 532
 533                 goto ipv6;
 534         case IPPROTO_MPLS:
 535                 proto = htons(ETH_P_MPLS_UC);
 536                 goto mpls;
 537         default:
 538                 break;
 539         }
 540
 541         if (dissector_uses_key(flow_dissector,
 542                                FLOW_DISSECTOR_KEY_PORTS)) {
 543                 key_ports = skb_flow_dissector_target(flow_dissector,
 544                                                       FLOW_DISSECTOR_KEY_PORTS,
 545                                                       target_container);
 546                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 547                                                         data, hlen);
 548         }
 549
 550 out_good:
 551         ret = true;
 552
 553 out:
 554         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
 555         key_basic->n_proto = proto;
 556         key_basic->ip_proto = ip_proto;
 557
 558         return ret;
 559
 560 out_bad:
 561         ret = false;
 562         goto out;
 563 }
 564 EXPORT_SYMBOL(__skb_flow_dissect);
 565
 566 static u32 hashrnd __read_mostly;
 567 static __always_inline void __flow_hash_secret_init(void)
 568 {
 569         net_get_random_once(&hashrnd, sizeof(hashrnd));
 570 }
 571
 572 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 573                                              u32 keyval)
 574 {
 575         return jhash2(words, length, keyval);
 576 }
 577
 578 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
 579 {
 580         const void *p = flow;
 581
 582         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 583         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
 584 }
 585
 586 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 587 {
 588         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 589         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 590         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 591                      sizeof(*flow) - sizeof(flow->addrs));
 592
 593         switch (flow->control.addr_type) {
 594         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 595                 diff -= sizeof(flow->addrs.v4addrs);
 596                 break;
 597         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 598                 diff -= sizeof(flow->addrs.v6addrs);
 599                 break;
 600         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 601                 diff -= sizeof(flow->addrs.tipcaddrs);
 602                 break;
 603         }
 604         return (sizeof(*flow) - diff) / sizeof(u32);
 605 }
 606
 607 __be32 flow_get_u32_src(const struct flow_keys *flow)
 608 {
 609         switch (flow->control.addr_type) {
 610         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 611                 return flow->addrs.v4addrs.src;
 612         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 613                 return (__force __be32)ipv6_addr_hash(
 614                         &flow->addrs.v6addrs.src);
 615         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 616                 return flow->addrs.tipcaddrs.srcnode;
 617         default:
 618                 return 0;
 619         }
 620 }
 621 EXPORT_SYMBOL(flow_get_u32_src);
 622
 623 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 624 {
 625         switch (flow->control.addr_type) {
 626         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 627                 return flow->addrs.v4addrs.dst;
 628         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 629                 return (__force __be32)ipv6_addr_hash(
 630                         &flow->addrs.v6addrs.dst);
 631         default:
 632                 return 0;
 633         }
 634 }
 635 EXPORT_SYMBOL(flow_get_u32_dst);
 636
 637 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 638 {
 639         int addr_diff, i;
 640
 641         switch (keys->control.addr_type) {
 642         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 643                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 644                             (__force u32)keys->addrs.v4addrs.src;
 645                 if ((addr_diff < 0) ||
 646                     (addr_diff == 0 &&
 647                      ((__force u16)keys->ports.dst <
 648                       (__force u16)keys->ports.src))) {
 649                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 650                         swap(keys->ports.src, keys->ports.dst);
 651                 }
 652                 break;
 653         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 654                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 655                                    &keys->addrs.v6addrs.src,
 656                                    sizeof(keys->addrs.v6addrs.dst));
 657                 if ((addr_diff < 0) ||
 658                     (addr_diff == 0 &&
 659                      ((__force u16)keys->ports.dst <
 660                       (__force u16)keys->ports.src))) {
 661                         for (i = 0; i < 4; i++)
 662                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 663                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 664                         swap(keys->ports.src, keys->ports.dst);
 665                 }
 666                 break;
 667         }
 668 }
 669
 670 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 671 {
 672         u32 hash;
 673
 674         __flow_hash_consistentify(keys);
 675
 676         hash = __flow_hash_words(flow_keys_hash_start(keys),
 677                                  flow_keys_hash_length(keys), keyval);
 678         if (!hash)
 679                 hash = 1;
 680
 681         return hash;
 682 }
 683
 684 u32 flow_hash_from_keys(struct flow_keys *keys)
 685 {
 686         __flow_hash_secret_init();
 687         return __flow_hash_from_keys(keys, hashrnd);
 688 }
 689 EXPORT_SYMBOL(flow_hash_from_keys);
 690
 691 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 692                                   struct flow_keys *keys, u32 keyval)
 693 {
 694         skb_flow_dissect_flow_keys(skb, keys,
 695                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 696
 697         return __flow_hash_from_keys(keys, keyval);
 698 }
 699
 700 struct _flow_keys_digest_data {
 701         __be16  n_proto;
 702         u8      ip_proto;
 703         u8      padding;
 704         __be32  ports;
 705         __be32  src;
 706         __be32  dst;
 707 };
 708
 709 void make_flow_keys_digest(struct flow_keys_digest *digest,
 710                            const struct flow_keys *flow)
 711 {
 712         struct _flow_keys_digest_data *data =
 713             (struct _flow_keys_digest_data *)digest;
 714
 715         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 716
 717         memset(digest, 0, sizeof(*digest));
 718
 719         data->n_proto = flow->basic.n_proto;
 720         data->ip_proto = flow->basic.ip_proto;
 721         data->ports = flow->ports.ports;
 722         data->src = flow->addrs.v4addrs.src;
 723         data->dst = flow->addrs.v4addrs.dst;
 724 }
 725 EXPORT_SYMBOL(make_flow_keys_digest);
 726
 727 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
 728
 729 u32 __skb_get_hash_symmetric(struct sk_buff *skb)
 730 {
 731         struct flow_keys keys;
 732
 733         __flow_hash_secret_init();
 734
 735         memset(&keys, 0, sizeof(keys));
 736         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
 737                            NULL, 0, 0, 0,
 738                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 739
 740         return __flow_hash_from_keys(&keys, hashrnd);
 741 }
 742 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
 743
 744 /**
 745  * __skb_get_hash: calculate a flow hash
 746  * @skb: sk_buff to calculate flow hash from
 747  *
 748  * This function calculates a flow hash based on src/dst addresses
 749  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 750  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 751  * if hash is a canonical 4-tuple hash over transport ports.
 752  */
 753 void __skb_get_hash(struct sk_buff *skb)
 754 {
 755         struct flow_keys keys;
 756         u32 hash;
 757
 758         __flow_hash_secret_init();
 759
 760         hash = ___skb_get_hash(skb, &keys, hashrnd);
 761
 762         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
 763 }
 764 EXPORT_SYMBOL(__skb_get_hash);
 765
 766 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 767 {
 768         struct flow_keys keys;
 769
 770         return ___skb_get_hash(skb, &keys, perturb);
 771 }
 772 EXPORT_SYMBOL(skb_get_hash_perturb);
 773
 774 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 775 {
 776         struct flow_keys keys;
 777
 778         memset(&keys, 0, sizeof(keys));
 779
 780         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 781                sizeof(keys.addrs.v6addrs.src));
 782         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 783                sizeof(keys.addrs.v6addrs.dst));
 784         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 785         keys.ports.src = fl6->fl6_sport;
 786         keys.ports.dst = fl6->fl6_dport;
 787         keys.keyid.keyid = fl6->fl6_gre_key;
 788         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 789         keys.basic.ip_proto = fl6->flowi6_proto;
 790
 791         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 792                           flow_keys_have_l4(&keys));
 793
 794         return skb->hash;
 795 }
 796 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 797
 798 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 799 {
 800         struct flow_keys keys;
 801
 802         memset(&keys, 0, sizeof(keys));
 803
 804         keys.addrs.v4addrs.src = fl4->saddr;
 805         keys.addrs.v4addrs.dst = fl4->daddr;
 806         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 807         keys.ports.src = fl4->fl4_sport;
 808         keys.ports.dst = fl4->fl4_dport;
 809         keys.keyid.keyid = fl4->fl4_gre_key;
 810         keys.basic.ip_proto = fl4->flowi4_proto;
 811
 812         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 813                           flow_keys_have_l4(&keys));
 814
 815         return skb->hash;
 816 }
 817 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 818
 819 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 820                    const struct flow_keys *keys, int hlen)
 821 {
 822         u32 poff = keys->control.thoff;
 823
 824         /* skip L4 headers for fragments after the first */
 825         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
 826             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
 827                 return poff;
 828
 829         switch (keys->basic.ip_proto) {
 830         case IPPROTO_TCP: {
 831                 /* access doff as u8 to avoid unaligned access */
 832                 const u8 *doff;
 833                 u8 _doff;
 834
 835                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 836                                             data, hlen, &_doff);
 837                 if (!doff)
 838                         return poff;
 839
 840                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 841                 break;
 842         }
 843         case IPPROTO_UDP:
 844         case IPPROTO_UDPLITE:
 845                 poff += sizeof(struct udphdr);
 846                 break;
 847         /* For the rest, we do not really care about header
 848          * extensions at this point for now.
 849          */
 850         case IPPROTO_ICMP:
 851                 poff += sizeof(struct icmphdr);
 852                 break;
 853         case IPPROTO_ICMPV6:
 854                 poff += sizeof(struct icmp6hdr);
 855                 break;
 856         case IPPROTO_IGMP:
 857                 poff += sizeof(struct igmphdr);
 858                 break;
 859         case IPPROTO_DCCP:
 860                 poff += sizeof(struct dccp_hdr);
 861                 break;
 862         case IPPROTO_SCTP:
 863                 poff += sizeof(struct sctphdr);
 864                 break;
 865         }
 866
 867         return poff;
 868 }
 869
 870 /**
 871  * skb_get_poff - get the offset to the payload
 872  * @skb: sk_buff to get the payload offset from
 873  *
 874  * The function will get the offset to the payload as far as it could
 875  * be dissected.  The main user is currently BPF, so that we can dynamically
 876  * truncate packets without needing to push actual payload to the user
 877  * space and can analyze headers only, instead.
 878  */
 879 u32 skb_get_poff(const struct sk_buff *skb)
 880 {
 881         struct flow_keys keys;
 882
 883         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 884                 return 0;
 885
 886         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 887 }
 888
 889 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 890 {
 891         memset(keys, 0, sizeof(*keys));
 892
 893         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 894             sizeof(keys->addrs.v6addrs.src));
 895         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 896             sizeof(keys->addrs.v6addrs.dst));
 897         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 898         keys->ports.src = fl6->fl6_sport;
 899         keys->ports.dst = fl6->fl6_dport;
 900         keys->keyid.keyid = fl6->fl6_gre_key;
 901         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 902         keys->basic.ip_proto = fl6->flowi6_proto;
 903
 904         return flow_hash_from_keys(keys);
 905 }
 906 EXPORT_SYMBOL(__get_hash_from_flowi6);
 907
 908 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 909 {
 910         memset(keys, 0, sizeof(*keys));
 911
 912         keys->addrs.v4addrs.src = fl4->saddr;
 913         keys->addrs.v4addrs.dst = fl4->daddr;
 914         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 915         keys->ports.src = fl4->fl4_sport;
 916         keys->ports.dst = fl4->fl4_dport;
 917         keys->keyid.keyid = fl4->fl4_gre_key;
 918         keys->basic.ip_proto = fl4->flowi4_proto;
 919
 920         return flow_hash_from_keys(keys);
 921 }
 922 EXPORT_SYMBOL(__get_hash_from_flowi4);
 923
 924 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 925         {
 926                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 927                 .offset = offsetof(struct flow_keys, control),
 928         },
 929         {
 930                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 931                 .offset = offsetof(struct flow_keys, basic),
 932         },
 933         {
 934                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 935                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 936         },
 937         {
 938                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 939                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 940         },
 941         {
 942                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 943                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 944         },
 945         {
 946                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 947                 .offset = offsetof(struct flow_keys, ports),
 948         },
 949         {
 950                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
 951                 .offset = offsetof(struct flow_keys, vlan),
 952         },
 953         {
 954                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 955                 .offset = offsetof(struct flow_keys, tags),
 956         },
 957         {
 958                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 959                 .offset = offsetof(struct flow_keys, keyid),
 960         },
 961 };
 962
 963 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
 964         {
 965                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 966                 .offset = offsetof(struct flow_keys, control),
 967         },
 968         {
 969                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 970                 .offset = offsetof(struct flow_keys, basic),
 971         },
 972         {
 973                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 974                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 975         },
 976         {
 977                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 978                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 979         },
 980         {
 981                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 982                 .offset = offsetof(struct flow_keys, ports),
 983         },
 984 };
 985
 986 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 987         {
 988                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 989                 .offset = offsetof(struct flow_keys, control),
 990         },
 991         {
 992                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 993                 .offset = offsetof(struct flow_keys, basic),
 994         },
 995 };
 996
 997 struct flow_dissector flow_keys_dissector __read_mostly;
 998 EXPORT_SYMBOL(flow_keys_dissector);
 999
1000 struct flow_dissector flow_keys_buf_dissector __read_mostly;
1001
1002 static int __init init_default_flow_dissectors(void)
1003 {
1004         skb_flow_dissector_init(&flow_keys_dissector,
1005                                 flow_keys_dissector_keys,
1006                                 ARRAY_SIZE(flow_keys_dissector_keys));
1007         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1008                                 flow_keys_dissector_symmetric_keys,
1009                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1010         skb_flow_dissector_init(&flow_keys_buf_dissector,
1011                                 flow_keys_buf_dissector_keys,
1012                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1013         return 0;
1014 }
1015
1016 core_initcall(init_default_flow_dissectors);