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