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 = false;
 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
 250                 if (skb_vlan_tag_present(skb))
 251                         proto = skb->protocol;
 252
 253                 if (!skb_vlan_tag_present(skb) ||
 254                     proto == cpu_to_be16(ETH_P_8021Q) ||
 255                     proto == cpu_to_be16(ETH_P_8021AD)) {
 256                         struct vlan_hdr _vlan;
 257
 258                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 259                                                     data, hlen, &_vlan);
 260                         if (!vlan)
 261                                 goto out_bad;
 262                         proto = vlan->h_vlan_encapsulated_proto;
 263                         nhoff += sizeof(*vlan);
 264                         if (skip_vlan)
 265                                 goto again;
 266                 }
 267
 268                 skip_vlan = true;
 269                 if (dissector_uses_key(flow_dissector,
 270                                        FLOW_DISSECTOR_KEY_VLAN)) {
 271                         key_vlan = skb_flow_dissector_target(flow_dissector,
 272                                                              FLOW_DISSECTOR_KEY_VLAN,
 273                                                              target_container);
 274
 275                         if (skb_vlan_tag_present(skb)) {
 276                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 277                                 key_vlan->vlan_priority =
 278                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 279                         } else {
 280                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 281                                         VLAN_VID_MASK;
 282                                 key_vlan->vlan_priority =
 283                                         (ntohs(vlan->h_vlan_TCI) &
 284                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 285                         }
 286                 }
 287
 288                 goto again;
 289         }
 290         case htons(ETH_P_PPP_SES): {
 291                 struct {
 292                         struct pppoe_hdr hdr;
 293                         __be16 proto;
 294                 } *hdr, _hdr;
 295                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 296                 if (!hdr)
 297                         goto out_bad;
 298                 proto = hdr->proto;
 299                 nhoff += PPPOE_SES_HLEN;
 300                 switch (proto) {
 301                 case htons(PPP_IP):
 302                         goto ip;
 303                 case htons(PPP_IPV6):
 304                         goto ipv6;
 305                 default:
 306                         goto out_bad;
 307                 }
 308         }
 309         case htons(ETH_P_TIPC): {
 310                 struct {
 311                         __be32 pre[3];
 312                         __be32 srcnode;
 313                 } *hdr, _hdr;
 314                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 315                 if (!hdr)
 316                         goto out_bad;
 317
 318                 if (dissector_uses_key(flow_dissector,
 319                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 320                         key_addrs = skb_flow_dissector_target(flow_dissector,
 321                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 322                                                               target_container);
 323                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 324                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 325                 }
 326                 goto out_good;
 327         }
 328
 329         case htons(ETH_P_MPLS_UC):
 330         case htons(ETH_P_MPLS_MC): {
 331                 struct mpls_label *hdr, _hdr[2];
 332 mpls:
 333                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 334                                            hlen, &_hdr);
 335                 if (!hdr)
 336                         goto out_bad;
 337
 338                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 339                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 340                         if (dissector_uses_key(flow_dissector,
 341                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 342                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 343                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 344                                                                       target_container);
 345                                 key_keyid->keyid = hdr[1].entry &
 346                                         htonl(MPLS_LS_LABEL_MASK);
 347                         }
 348
 349                         goto out_good;
 350                 }
 351
 352                 goto out_good;
 353         }
 354
 355         case htons(ETH_P_FCOE):
 356                 if ((hlen - nhoff) < FCOE_HEADER_LEN)
 357                         goto out_bad;
 358
 359                 nhoff += FCOE_HEADER_LEN;
 360                 goto out_good;
 361         default:
 362                 goto out_bad;
 363         }
 364
 365 ip_proto_again:
 366         switch (ip_proto) {
 367         case IPPROTO_GRE: {
 368                 struct gre_base_hdr *hdr, _hdr;
 369                 u16 gre_ver;
 370                 int offset = 0;
 371
 372                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 373                 if (!hdr)
 374                         goto out_bad;
 375
 376                 /* Only look inside GRE without routing */
 377                 if (hdr->flags & GRE_ROUTING)
 378                         break;
 379
 380                 /* Only look inside GRE for version 0 and 1 */
 381                 gre_ver = ntohs(hdr->flags & GRE_VERSION);
 382                 if (gre_ver > 1)
 383                         break;
 384
 385                 proto = hdr->protocol;
 386                 if (gre_ver) {
 387                         /* Version1 must be PPTP, and check the flags */
 388                         if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 389                                 break;
 390                 }
 391
 392                 offset += sizeof(struct gre_base_hdr);
 393
 394                 if (hdr->flags & GRE_CSUM)
 395                         offset += sizeof(((struct gre_full_hdr *)0)->csum) +
 396                                   sizeof(((struct gre_full_hdr *)0)->reserved1);
 397
 398                 if (hdr->flags & GRE_KEY) {
 399                         const __be32 *keyid;
 400                         __be32 _keyid;
 401
 402                         keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid),
 403                                                      data, hlen, &_keyid);
 404                         if (!keyid)
 405                                 goto out_bad;
 406
 407                         if (dissector_uses_key(flow_dissector,
 408                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 409                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 410                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 411                                                                       target_container);
 412                                 if (gre_ver == 0)
 413                                         key_keyid->keyid = *keyid;
 414                                 else
 415                                         key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 416                         }
 417                         offset += sizeof(((struct gre_full_hdr *)0)->key);
 418                 }
 419
 420                 if (hdr->flags & GRE_SEQ)
 421                         offset += sizeof(((struct pptp_gre_header *)0)->seq);
 422
 423                 if (gre_ver == 0) {
 424                         if (proto == htons(ETH_P_TEB)) {
 425                                 const struct ethhdr *eth;
 426                                 struct ethhdr _eth;
 427
 428                                 eth = __skb_header_pointer(skb, nhoff + offset,
 429                                                            sizeof(_eth),
 430                                                            data, hlen, &_eth);
 431                                 if (!eth)
 432                                         goto out_bad;
 433                                 proto = eth->h_proto;
 434                                 offset += sizeof(*eth);
 435
 436                                 /* Cap headers that we access via pointers at the
 437                                  * end of the Ethernet header as our maximum alignment
 438                                  * at that point is only 2 bytes.
 439                                  */
 440                                 if (NET_IP_ALIGN)
 441                                         hlen = (nhoff + offset);
 442                         }
 443                 } else { /* version 1, must be PPTP */
 444                         u8 _ppp_hdr[PPP_HDRLEN];
 445                         u8 *ppp_hdr;
 446
 447                         if (hdr->flags & GRE_ACK)
 448                                 offset += sizeof(((struct pptp_gre_header *)0)->ack);
 449
 450                         ppp_hdr = skb_header_pointer(skb, nhoff + offset,
 451                                                      sizeof(_ppp_hdr), _ppp_hdr);
 452                         if (!ppp_hdr)
 453                                 goto out_bad;
 454
 455                         switch (PPP_PROTOCOL(ppp_hdr)) {
 456                         case PPP_IP:
 457                                 proto = htons(ETH_P_IP);
 458                                 break;
 459                         case PPP_IPV6:
 460                                 proto = htons(ETH_P_IPV6);
 461                                 break;
 462                         default:
 463                                 /* Could probably catch some more like MPLS */
 464                                 break;
 465                         }
 466
 467                         offset += PPP_HDRLEN;
 468                 }
 469
 470                 nhoff += offset;
 471                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 472                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 473                         goto out_good;
 474
 475                 goto again;
 476         }
 477         case NEXTHDR_HOP:
 478         case NEXTHDR_ROUTING:
 479         case NEXTHDR_DEST: {
 480                 u8 _opthdr[2], *opthdr;
 481
 482                 if (proto != htons(ETH_P_IPV6))
 483                         break;
 484
 485                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 486                                               data, hlen, &_opthdr);
 487                 if (!opthdr)
 488                         goto out_bad;
 489
 490                 ip_proto = opthdr[0];
 491                 nhoff += (opthdr[1] + 1) << 3;
 492
 493                 goto ip_proto_again;
 494         }
 495         case NEXTHDR_FRAGMENT: {
 496                 struct frag_hdr _fh, *fh;
 497
 498                 if (proto != htons(ETH_P_IPV6))
 499                         break;
 500
 501                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 502                                           data, hlen, &_fh);
 503
 504                 if (!fh)
 505                         goto out_bad;
 506
 507                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 508
 509                 nhoff += sizeof(_fh);
 510                 ip_proto = fh->nexthdr;
 511
 512                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 513                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 514                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
 515                                 goto ip_proto_again;
 516                 }
 517                 goto out_good;
 518         }
 519         case IPPROTO_IPIP:
 520                 proto = htons(ETH_P_IP);
 521
 522                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 523                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 524                         goto out_good;
 525
 526                 goto ip;
 527         case IPPROTO_IPV6:
 528                 proto = htons(ETH_P_IPV6);
 529
 530                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 531                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 532                         goto out_good;
 533
 534                 goto ipv6;
 535         case IPPROTO_MPLS:
 536                 proto = htons(ETH_P_MPLS_UC);
 537                 goto mpls;
 538         default:
 539                 break;
 540         }
 541
 542         if (dissector_uses_key(flow_dissector,
 543                                FLOW_DISSECTOR_KEY_PORTS)) {
 544                 key_ports = skb_flow_dissector_target(flow_dissector,
 545                                                       FLOW_DISSECTOR_KEY_PORTS,
 546                                                       target_container);
 547                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 548                                                         data, hlen);
 549         }
 550
 551 out_good:
 552         ret = true;
 553
 554 out_bad:
 555         key_basic->n_proto = proto;
 556         key_basic->ip_proto = ip_proto;
 557         key_control->thoff = (u16)nhoff;
 558
 559         return ret;
 560 }
 561 EXPORT_SYMBOL(__skb_flow_dissect);
 562
 563 static u32 hashrnd __read_mostly;
 564 static __always_inline void __flow_hash_secret_init(void)
 565 {
 566         net_get_random_once(&hashrnd, sizeof(hashrnd));
 567 }
 568
 569 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 570                                              u32 keyval)
 571 {
 572         return jhash2(words, length, keyval);
 573 }
 574
 575 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
 576 {
 577         const void *p = flow;
 578
 579         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 580         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
 581 }
 582
 583 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 584 {
 585         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 586         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 587         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 588                      sizeof(*flow) - sizeof(flow->addrs));
 589
 590         switch (flow->control.addr_type) {
 591         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 592                 diff -= sizeof(flow->addrs.v4addrs);
 593                 break;
 594         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 595                 diff -= sizeof(flow->addrs.v6addrs);
 596                 break;
 597         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 598                 diff -= sizeof(flow->addrs.tipcaddrs);
 599                 break;
 600         }
 601         return (sizeof(*flow) - diff) / sizeof(u32);
 602 }
 603
 604 __be32 flow_get_u32_src(const struct flow_keys *flow)
 605 {
 606         switch (flow->control.addr_type) {
 607         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 608                 return flow->addrs.v4addrs.src;
 609         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 610                 return (__force __be32)ipv6_addr_hash(
 611                         &flow->addrs.v6addrs.src);
 612         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 613                 return flow->addrs.tipcaddrs.srcnode;
 614         default:
 615                 return 0;
 616         }
 617 }
 618 EXPORT_SYMBOL(flow_get_u32_src);
 619
 620 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 621 {
 622         switch (flow->control.addr_type) {
 623         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 624                 return flow->addrs.v4addrs.dst;
 625         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 626                 return (__force __be32)ipv6_addr_hash(
 627                         &flow->addrs.v6addrs.dst);
 628         default:
 629                 return 0;
 630         }
 631 }
 632 EXPORT_SYMBOL(flow_get_u32_dst);
 633
 634 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 635 {
 636         int addr_diff, i;
 637
 638         switch (keys->control.addr_type) {
 639         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 640                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 641                             (__force u32)keys->addrs.v4addrs.src;
 642                 if ((addr_diff < 0) ||
 643                     (addr_diff == 0 &&
 644                      ((__force u16)keys->ports.dst <
 645                       (__force u16)keys->ports.src))) {
 646                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 647                         swap(keys->ports.src, keys->ports.dst);
 648                 }
 649                 break;
 650         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 651                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 652                                    &keys->addrs.v6addrs.src,
 653                                    sizeof(keys->addrs.v6addrs.dst));
 654                 if ((addr_diff < 0) ||
 655                     (addr_diff == 0 &&
 656                      ((__force u16)keys->ports.dst <
 657                       (__force u16)keys->ports.src))) {
 658                         for (i = 0; i < 4; i++)
 659                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 660                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 661                         swap(keys->ports.src, keys->ports.dst);
 662                 }
 663                 break;
 664         }
 665 }
 666
 667 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 668 {
 669         u32 hash;
 670
 671         __flow_hash_consistentify(keys);
 672
 673         hash = __flow_hash_words(flow_keys_hash_start(keys),
 674                                  flow_keys_hash_length(keys), keyval);
 675         if (!hash)
 676                 hash = 1;
 677
 678         return hash;
 679 }
 680
 681 u32 flow_hash_from_keys(struct flow_keys *keys)
 682 {
 683         __flow_hash_secret_init();
 684         return __flow_hash_from_keys(keys, hashrnd);
 685 }
 686 EXPORT_SYMBOL(flow_hash_from_keys);
 687
 688 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 689                                   struct flow_keys *keys, u32 keyval)
 690 {
 691         skb_flow_dissect_flow_keys(skb, keys,
 692                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 693
 694         return __flow_hash_from_keys(keys, keyval);
 695 }
 696
 697 struct _flow_keys_digest_data {
 698         __be16  n_proto;
 699         u8      ip_proto;
 700         u8      padding;
 701         __be32  ports;
 702         __be32  src;
 703         __be32  dst;
 704 };
 705
 706 void make_flow_keys_digest(struct flow_keys_digest *digest,
 707                            const struct flow_keys *flow)
 708 {
 709         struct _flow_keys_digest_data *data =
 710             (struct _flow_keys_digest_data *)digest;
 711
 712         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 713
 714         memset(digest, 0, sizeof(*digest));
 715
 716         data->n_proto = flow->basic.n_proto;
 717         data->ip_proto = flow->basic.ip_proto;
 718         data->ports = flow->ports.ports;
 719         data->src = flow->addrs.v4addrs.src;
 720         data->dst = flow->addrs.v4addrs.dst;
 721 }
 722 EXPORT_SYMBOL(make_flow_keys_digest);
 723
 724 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
 725
 726 u32 __skb_get_hash_symmetric(struct sk_buff *skb)
 727 {
 728         struct flow_keys keys;
 729
 730         __flow_hash_secret_init();
 731
 732         memset(&keys, 0, sizeof(keys));
 733         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
 734                            NULL, 0, 0, 0,
 735                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 736
 737         return __flow_hash_from_keys(&keys, hashrnd);
 738 }
 739 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
 740
 741 /**
 742  * __skb_get_hash: calculate a flow hash
 743  * @skb: sk_buff to calculate flow hash from
 744  *
 745  * This function calculates a flow hash based on src/dst addresses
 746  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 747  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 748  * if hash is a canonical 4-tuple hash over transport ports.
 749  */
 750 void __skb_get_hash(struct sk_buff *skb)
 751 {
 752         struct flow_keys keys;
 753         u32 hash;
 754
 755         __flow_hash_secret_init();
 756
 757         hash = ___skb_get_hash(skb, &keys, hashrnd);
 758
 759         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
 760 }
 761 EXPORT_SYMBOL(__skb_get_hash);
 762
 763 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 764 {
 765         struct flow_keys keys;
 766
 767         return ___skb_get_hash(skb, &keys, perturb);
 768 }
 769 EXPORT_SYMBOL(skb_get_hash_perturb);
 770
 771 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 772 {
 773         struct flow_keys keys;
 774
 775         memset(&keys, 0, sizeof(keys));
 776
 777         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 778                sizeof(keys.addrs.v6addrs.src));
 779         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 780                sizeof(keys.addrs.v6addrs.dst));
 781         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 782         keys.ports.src = fl6->fl6_sport;
 783         keys.ports.dst = fl6->fl6_dport;
 784         keys.keyid.keyid = fl6->fl6_gre_key;
 785         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 786         keys.basic.ip_proto = fl6->flowi6_proto;
 787
 788         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 789                           flow_keys_have_l4(&keys));
 790
 791         return skb->hash;
 792 }
 793 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 794
 795 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 796 {
 797         struct flow_keys keys;
 798
 799         memset(&keys, 0, sizeof(keys));
 800
 801         keys.addrs.v4addrs.src = fl4->saddr;
 802         keys.addrs.v4addrs.dst = fl4->daddr;
 803         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 804         keys.ports.src = fl4->fl4_sport;
 805         keys.ports.dst = fl4->fl4_dport;
 806         keys.keyid.keyid = fl4->fl4_gre_key;
 807         keys.basic.ip_proto = fl4->flowi4_proto;
 808
 809         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 810                           flow_keys_have_l4(&keys));
 811
 812         return skb->hash;
 813 }
 814 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 815
 816 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 817                    const struct flow_keys *keys, int hlen)
 818 {
 819         u32 poff = keys->control.thoff;
 820
 821         /* skip L4 headers for fragments after the first */
 822         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
 823             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
 824                 return poff;
 825
 826         switch (keys->basic.ip_proto) {
 827         case IPPROTO_TCP: {
 828                 /* access doff as u8 to avoid unaligned access */
 829                 const u8 *doff;
 830                 u8 _doff;
 831
 832                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 833                                             data, hlen, &_doff);
 834                 if (!doff)
 835                         return poff;
 836
 837                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 838                 break;
 839         }
 840         case IPPROTO_UDP:
 841         case IPPROTO_UDPLITE:
 842                 poff += sizeof(struct udphdr);
 843                 break;
 844         /* For the rest, we do not really care about header
 845          * extensions at this point for now.
 846          */
 847         case IPPROTO_ICMP:
 848                 poff += sizeof(struct icmphdr);
 849                 break;
 850         case IPPROTO_ICMPV6:
 851                 poff += sizeof(struct icmp6hdr);
 852                 break;
 853         case IPPROTO_IGMP:
 854                 poff += sizeof(struct igmphdr);
 855                 break;
 856         case IPPROTO_DCCP:
 857                 poff += sizeof(struct dccp_hdr);
 858                 break;
 859         case IPPROTO_SCTP:
 860                 poff += sizeof(struct sctphdr);
 861                 break;
 862         }
 863
 864         return poff;
 865 }
 866
 867 /**
 868  * skb_get_poff - get the offset to the payload
 869  * @skb: sk_buff to get the payload offset from
 870  *
 871  * The function will get the offset to the payload as far as it could
 872  * be dissected.  The main user is currently BPF, so that we can dynamically
 873  * truncate packets without needing to push actual payload to the user
 874  * space and can analyze headers only, instead.
 875  */
 876 u32 skb_get_poff(const struct sk_buff *skb)
 877 {
 878         struct flow_keys keys;
 879
 880         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 881                 return 0;
 882
 883         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 884 }
 885
 886 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 887 {
 888         memset(keys, 0, sizeof(*keys));
 889
 890         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 891             sizeof(keys->addrs.v6addrs.src));
 892         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 893             sizeof(keys->addrs.v6addrs.dst));
 894         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 895         keys->ports.src = fl6->fl6_sport;
 896         keys->ports.dst = fl6->fl6_dport;
 897         keys->keyid.keyid = fl6->fl6_gre_key;
 898         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 899         keys->basic.ip_proto = fl6->flowi6_proto;
 900
 901         return flow_hash_from_keys(keys);
 902 }
 903 EXPORT_SYMBOL(__get_hash_from_flowi6);
 904
 905 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 906 {
 907         memset(keys, 0, sizeof(*keys));
 908
 909         keys->addrs.v4addrs.src = fl4->saddr;
 910         keys->addrs.v4addrs.dst = fl4->daddr;
 911         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 912         keys->ports.src = fl4->fl4_sport;
 913         keys->ports.dst = fl4->fl4_dport;
 914         keys->keyid.keyid = fl4->fl4_gre_key;
 915         keys->basic.ip_proto = fl4->flowi4_proto;
 916
 917         return flow_hash_from_keys(keys);
 918 }
 919 EXPORT_SYMBOL(__get_hash_from_flowi4);
 920
 921 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 922         {
 923                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 924                 .offset = offsetof(struct flow_keys, control),
 925         },
 926         {
 927                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 928                 .offset = offsetof(struct flow_keys, basic),
 929         },
 930         {
 931                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 932                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 933         },
 934         {
 935                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 936                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 937         },
 938         {
 939                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 940                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 941         },
 942         {
 943                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 944                 .offset = offsetof(struct flow_keys, ports),
 945         },
 946         {
 947                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
 948                 .offset = offsetof(struct flow_keys, vlan),
 949         },
 950         {
 951                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 952                 .offset = offsetof(struct flow_keys, tags),
 953         },
 954         {
 955                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 956                 .offset = offsetof(struct flow_keys, keyid),
 957         },
 958 };
 959
 960 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
 961         {
 962                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 963                 .offset = offsetof(struct flow_keys, control),
 964         },
 965         {
 966                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 967                 .offset = offsetof(struct flow_keys, basic),
 968         },
 969         {
 970                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 971                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 972         },
 973         {
 974                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 975                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 976         },
 977         {
 978                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 979                 .offset = offsetof(struct flow_keys, ports),
 980         },
 981 };
 982
 983 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 984         {
 985                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 986                 .offset = offsetof(struct flow_keys, control),
 987         },
 988         {
 989                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 990                 .offset = offsetof(struct flow_keys, basic),
 991         },
 992 };
 993
 994 struct flow_dissector flow_keys_dissector __read_mostly;
 995 EXPORT_SYMBOL(flow_keys_dissector);
 996
 997 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 998
 999 static int __init init_default_flow_dissectors(void)
1000 {
1001         skb_flow_dissector_init(&flow_keys_dissector,
1002                                 flow_keys_dissector_keys,
1003                                 ARRAY_SIZE(flow_keys_dissector_keys));
1004         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1005                                 flow_keys_dissector_symmetric_keys,
1006                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1007         skb_flow_dissector_init(&flow_keys_buf_dissector,
1008                                 flow_keys_buf_dissector_keys,
1009                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1010         return 0;
1011 }
1012
1013 late_initcall_sync(init_default_flow_dissectors);