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 <linux/igmp.h>
  10 #include <linux/icmp.h>
  11 #include <linux/sctp.h>
  12 #include <linux/dccp.h>
  13 #include <linux/if_tunnel.h>
  14 #include <linux/if_pppox.h>
  15 #include <linux/ppp_defs.h>
  16 #include <linux/stddef.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/mpls.h>
  19 #include <net/flow_dissector.h>
  20 #include <scsi/fc/fc_fcoe.h>
  21
  22 static bool dissector_uses_key(const struct flow_dissector *flow_dissector,
  23                                enum flow_dissector_key_id key_id)
  24 {
  25         return flow_dissector->used_keys & (1 << key_id);
  26 }
  27
  28 static void dissector_set_key(struct flow_dissector *flow_dissector,
  29                               enum flow_dissector_key_id key_id)
  30 {
  31         flow_dissector->used_keys |= (1 << key_id);
  32 }
  33
  34 static void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
  35                                        enum flow_dissector_key_id key_id,
  36                                        void *target_container)
  37 {
  38         return ((char *) target_container) + flow_dissector->offset[key_id];
  39 }
  40
  41 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  42                              const struct flow_dissector_key *key,
  43                              unsigned int key_count)
  44 {
  45         unsigned int i;
  46
  47         memset(flow_dissector, 0, sizeof(*flow_dissector));
  48
  49         for (i = 0; i < key_count; i++, key++) {
  50                 /* User should make sure that every key target offset is withing
  51                  * boundaries of unsigned short.
  52                  */
  53                 BUG_ON(key->offset > USHRT_MAX);
  54                 BUG_ON(dissector_uses_key(flow_dissector,
  55                                           key->key_id));
  56
  57                 dissector_set_key(flow_dissector, key->key_id);
  58                 flow_dissector->offset[key->key_id] = key->offset;
  59         }
  60
  61         /* Ensure that the dissector always includes control and basic key.
  62          * That way we are able to avoid handling lack of these in fast path.
  63          */
  64         BUG_ON(!dissector_uses_key(flow_dissector,
  65                                    FLOW_DISSECTOR_KEY_CONTROL));
  66         BUG_ON(!dissector_uses_key(flow_dissector,
  67                                    FLOW_DISSECTOR_KEY_BASIC));
  68 }
  69 EXPORT_SYMBOL(skb_flow_dissector_init);
  70
  71 /**
  72  * __skb_flow_get_ports - extract the upper layer ports and return them
  73  * @skb: sk_buff to extract the ports from
  74  * @thoff: transport header offset
  75  * @ip_proto: protocol for which to get port offset
  76  * @data: raw buffer pointer to the packet, if NULL use skb->data
  77  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  78  *
  79  * The function will try to retrieve the ports at offset thoff + poff where poff
  80  * is the protocol port offset returned from proto_ports_offset
  81  */
  82 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  83                             void *data, int hlen)
  84 {
  85         int poff = proto_ports_offset(ip_proto);
  86
  87         if (!data) {
  88                 data = skb->data;
  89                 hlen = skb_headlen(skb);
  90         }
  91
  92         if (poff >= 0) {
  93                 __be32 *ports, _ports;
  94
  95                 ports = __skb_header_pointer(skb, thoff + poff,
  96                                              sizeof(_ports), data, hlen, &_ports);
  97                 if (ports)
  98                         return *ports;
  99         }
 100
 101         return 0;
 102 }
 103 EXPORT_SYMBOL(__skb_flow_get_ports);
 104
 105 /**
 106  * __skb_flow_dissect - extract the flow_keys struct and return it
 107  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 108  * @flow_dissector: list of keys to dissect
 109  * @target_container: target structure to put dissected values into
 110  * @data: raw buffer pointer to the packet, if NULL use skb->data
 111  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 112  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 113  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 114  *
 115  * The function will try to retrieve individual keys into target specified
 116  * by flow_dissector from either the skbuff or a raw buffer specified by the
 117  * rest parameters.
 118  *
 119  * Caller must take care of zeroing target container memory.
 120  */
 121 bool __skb_flow_dissect(const struct sk_buff *skb,
 122                         struct flow_dissector *flow_dissector,
 123                         void *target_container,
 124                         void *data, __be16 proto, int nhoff, int hlen,
 125                         unsigned int flags)
 126 {
 127         struct flow_dissector_key_control *key_control;
 128         struct flow_dissector_key_basic *key_basic;
 129         struct flow_dissector_key_addrs *key_addrs;
 130         struct flow_dissector_key_ports *key_ports;
 131         struct flow_dissector_key_tags *key_tags;
 132         struct flow_dissector_key_keyid *key_keyid;
 133         u8 ip_proto = 0;
 134         bool ret = false;
 135
 136         if (!data) {
 137                 data = skb->data;
 138                 proto = skb->protocol;
 139                 nhoff = skb_network_offset(skb);
 140                 hlen = skb_headlen(skb);
 141         }
 142
 143         /* It is ensured by skb_flow_dissector_init() that control key will
 144          * be always present.
 145          */
 146         key_control = skb_flow_dissector_target(flow_dissector,
 147                                                 FLOW_DISSECTOR_KEY_CONTROL,
 148                                                 target_container);
 149
 150         /* It is ensured by skb_flow_dissector_init() that basic key will
 151          * be always present.
 152          */
 153         key_basic = skb_flow_dissector_target(flow_dissector,
 154                                               FLOW_DISSECTOR_KEY_BASIC,
 155                                               target_container);
 156
 157         if (dissector_uses_key(flow_dissector,
 158                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 159                 struct ethhdr *eth = eth_hdr(skb);
 160                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 161
 162                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 163                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 164                                                           target_container);
 165                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 166         }
 167
 168 again:
 169         switch (proto) {
 170         case htons(ETH_P_IP): {
 171                 const struct iphdr *iph;
 172                 struct iphdr _iph;
 173 ip:
 174                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 175                 if (!iph || iph->ihl < 5)
 176                         goto out_bad;
 177                 nhoff += iph->ihl * 4;
 178
 179                 ip_proto = iph->protocol;
 180
 181                 if (!dissector_uses_key(flow_dissector,
 182                                         FLOW_DISSECTOR_KEY_IPV4_ADDRS))
 183                         break;
 184
 185                 key_addrs = skb_flow_dissector_target(flow_dissector,
 186                               FLOW_DISSECTOR_KEY_IPV4_ADDRS, target_container);
 187                 memcpy(&key_addrs->v4addrs, &iph->saddr,
 188                        sizeof(key_addrs->v4addrs));
 189                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 190
 191                 if (ip_is_fragment(iph)) {
 192                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 193
 194                         if (iph->frag_off & htons(IP_OFFSET)) {
 195                                 goto out_good;
 196                         } else {
 197                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 198                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 199                                         goto out_good;
 200                         }
 201                 }
 202
 203                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 204                         goto out_good;
 205
 206                 break;
 207         }
 208         case htons(ETH_P_IPV6): {
 209                 const struct ipv6hdr *iph;
 210                 struct ipv6hdr _iph;
 211
 212 ipv6:
 213                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 214                 if (!iph)
 215                         goto out_bad;
 216
 217                 ip_proto = iph->nexthdr;
 218                 nhoff += sizeof(struct ipv6hdr);
 219
 220                 if (dissector_uses_key(flow_dissector,
 221                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 222                         struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs;
 223
 224                         key_ipv6_addrs = skb_flow_dissector_target(flow_dissector,
 225                                                                    FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 226                                                                    target_container);
 227
 228                         memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
 229                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 230                 }
 231
 232                 if ((dissector_uses_key(flow_dissector,
 233                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 234                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 235                     ip6_flowlabel(iph)) {
 236                         __be32 flow_label = ip6_flowlabel(iph);
 237
 238                         if (dissector_uses_key(flow_dissector,
 239                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 240                                 key_tags = skb_flow_dissector_target(flow_dissector,
 241                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 242                                                                      target_container);
 243                                 key_tags->flow_label = ntohl(flow_label);
 244                         }
 245                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 246                                 goto out_good;
 247                 }
 248
 249                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 250                         goto out_good;
 251
 252                 break;
 253         }
 254         case htons(ETH_P_8021AD):
 255         case htons(ETH_P_8021Q): {
 256                 const struct vlan_hdr *vlan;
 257                 struct vlan_hdr _vlan;
 258
 259                 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
 260                 if (!vlan)
 261                         goto out_bad;
 262
 263                 if (dissector_uses_key(flow_dissector,
 264                                        FLOW_DISSECTOR_KEY_VLANID)) {
 265                         key_tags = skb_flow_dissector_target(flow_dissector,
 266                                                              FLOW_DISSECTOR_KEY_VLANID,
 267                                                              target_container);
 268
 269                         key_tags->vlan_id = skb_vlan_tag_get_id(skb);
 270                 }
 271
 272                 proto = vlan->h_vlan_encapsulated_proto;
 273                 nhoff += sizeof(*vlan);
 274                 goto again;
 275         }
 276         case htons(ETH_P_PPP_SES): {
 277                 struct {
 278                         struct pppoe_hdr hdr;
 279                         __be16 proto;
 280                 } *hdr, _hdr;
 281                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 282                 if (!hdr)
 283                         goto out_bad;
 284                 proto = hdr->proto;
 285                 nhoff += PPPOE_SES_HLEN;
 286                 switch (proto) {
 287                 case htons(PPP_IP):
 288                         goto ip;
 289                 case htons(PPP_IPV6):
 290                         goto ipv6;
 291                 default:
 292                         goto out_bad;
 293                 }
 294         }
 295         case htons(ETH_P_TIPC): {
 296                 struct {
 297                         __be32 pre[3];
 298                         __be32 srcnode;
 299                 } *hdr, _hdr;
 300                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 301                 if (!hdr)
 302                         goto out_bad;
 303
 304                 if (dissector_uses_key(flow_dissector,
 305                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 306                         key_addrs = skb_flow_dissector_target(flow_dissector,
 307                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 308                                                               target_container);
 309                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 310                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 311                 }
 312                 goto out_good;
 313         }
 314
 315         case htons(ETH_P_MPLS_UC):
 316         case htons(ETH_P_MPLS_MC): {
 317                 struct mpls_label *hdr, _hdr[2];
 318 mpls:
 319                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 320                                            hlen, &_hdr);
 321                 if (!hdr)
 322                         goto out_bad;
 323
 324                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 325                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 326                         if (dissector_uses_key(flow_dissector,
 327                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 328                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 329                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 330                                                                       target_container);
 331                                 key_keyid->keyid = hdr[1].entry &
 332                                         htonl(MPLS_LS_LABEL_MASK);
 333                         }
 334
 335                         goto out_good;
 336                 }
 337
 338                 goto out_good;
 339         }
 340
 341         case htons(ETH_P_FCOE):
 342                 key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
 343                 /* fall through */
 344         default:
 345                 goto out_bad;
 346         }
 347
 348 ip_proto_again:
 349         switch (ip_proto) {
 350         case IPPROTO_GRE: {
 351                 struct gre_hdr {
 352                         __be16 flags;
 353                         __be16 proto;
 354                 } *hdr, _hdr;
 355
 356                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 357                 if (!hdr)
 358                         goto out_bad;
 359                 /*
 360                  * Only look inside GRE if version zero and no
 361                  * routing
 362                  */
 363                 if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
 364                         break;
 365
 366                 proto = hdr->proto;
 367                 nhoff += 4;
 368                 if (hdr->flags & GRE_CSUM)
 369                         nhoff += 4;
 370                 if (hdr->flags & GRE_KEY) {
 371                         const __be32 *keyid;
 372                         __be32 _keyid;
 373
 374                         keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
 375                                                      data, hlen, &_keyid);
 376
 377                         if (!keyid)
 378                                 goto out_bad;
 379
 380                         if (dissector_uses_key(flow_dissector,
 381                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 382                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 383                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 384                                                                       target_container);
 385                                 key_keyid->keyid = *keyid;
 386                         }
 387                         nhoff += 4;
 388                 }
 389                 if (hdr->flags & GRE_SEQ)
 390                         nhoff += 4;
 391                 if (proto == htons(ETH_P_TEB)) {
 392                         const struct ethhdr *eth;
 393                         struct ethhdr _eth;
 394
 395                         eth = __skb_header_pointer(skb, nhoff,
 396                                                    sizeof(_eth),
 397                                                    data, hlen, &_eth);
 398                         if (!eth)
 399                                 goto out_bad;
 400                         proto = eth->h_proto;
 401                         nhoff += sizeof(*eth);
 402                 }
 403
 404                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 405                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 406                         goto out_good;
 407
 408                 goto again;
 409         }
 410         case NEXTHDR_HOP:
 411         case NEXTHDR_ROUTING:
 412         case NEXTHDR_DEST: {
 413                 u8 _opthdr[2], *opthdr;
 414
 415                 if (proto != htons(ETH_P_IPV6))
 416                         break;
 417
 418                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 419                                               data, hlen, &_opthdr);
 420                 if (!opthdr)
 421                         goto out_bad;
 422
 423                 ip_proto = opthdr[0];
 424                 nhoff += (opthdr[1] + 1) << 3;
 425
 426                 goto ip_proto_again;
 427         }
 428         case NEXTHDR_FRAGMENT: {
 429                 struct frag_hdr _fh, *fh;
 430
 431                 if (proto != htons(ETH_P_IPV6))
 432                         break;
 433
 434                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 435                                           data, hlen, &_fh);
 436
 437                 if (!fh)
 438                         goto out_bad;
 439
 440                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 441
 442                 nhoff += sizeof(_fh);
 443
 444                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 445                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 446                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 447                                 ip_proto = fh->nexthdr;
 448                                 goto ip_proto_again;
 449                         }
 450                 }
 451                 goto out_good;
 452         }
 453         case IPPROTO_IPIP:
 454                 proto = htons(ETH_P_IP);
 455
 456                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 457                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 458                         goto out_good;
 459
 460                 goto ip;
 461         case IPPROTO_IPV6:
 462                 proto = htons(ETH_P_IPV6);
 463
 464                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 465                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 466                         goto out_good;
 467
 468                 goto ipv6;
 469         case IPPROTO_MPLS:
 470                 proto = htons(ETH_P_MPLS_UC);
 471                 goto mpls;
 472         default:
 473                 break;
 474         }
 475
 476         if (dissector_uses_key(flow_dissector,
 477                                FLOW_DISSECTOR_KEY_PORTS)) {
 478                 key_ports = skb_flow_dissector_target(flow_dissector,
 479                                                       FLOW_DISSECTOR_KEY_PORTS,
 480                                                       target_container);
 481                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 482                                                         data, hlen);
 483         }
 484
 485 out_good:
 486         ret = true;
 487
 488 out_bad:
 489         key_basic->n_proto = proto;
 490         key_basic->ip_proto = ip_proto;
 491         key_control->thoff = (u16)nhoff;
 492
 493         return ret;
 494 }
 495 EXPORT_SYMBOL(__skb_flow_dissect);
 496
 497 static u32 hashrnd __read_mostly;
 498 static __always_inline void __flow_hash_secret_init(void)
 499 {
 500         net_get_random_once(&hashrnd, sizeof(hashrnd));
 501 }
 502
 503 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
 504                                              u32 keyval)
 505 {
 506         return jhash2(words, length, keyval);
 507 }
 508
 509 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
 510 {
 511         const void *p = flow;
 512
 513         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 514         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
 515 }
 516
 517 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 518 {
 519         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 520         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 521         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 522                      sizeof(*flow) - sizeof(flow->addrs));
 523
 524         switch (flow->control.addr_type) {
 525         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 526                 diff -= sizeof(flow->addrs.v4addrs);
 527                 break;
 528         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 529                 diff -= sizeof(flow->addrs.v6addrs);
 530                 break;
 531         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 532                 diff -= sizeof(flow->addrs.tipcaddrs);
 533                 break;
 534         }
 535         return (sizeof(*flow) - diff) / sizeof(u32);
 536 }
 537
 538 __be32 flow_get_u32_src(const struct flow_keys *flow)
 539 {
 540         switch (flow->control.addr_type) {
 541         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 542                 return flow->addrs.v4addrs.src;
 543         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 544                 return (__force __be32)ipv6_addr_hash(
 545                         &flow->addrs.v6addrs.src);
 546         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 547                 return flow->addrs.tipcaddrs.srcnode;
 548         default:
 549                 return 0;
 550         }
 551 }
 552 EXPORT_SYMBOL(flow_get_u32_src);
 553
 554 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 555 {
 556         switch (flow->control.addr_type) {
 557         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 558                 return flow->addrs.v4addrs.dst;
 559         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 560                 return (__force __be32)ipv6_addr_hash(
 561                         &flow->addrs.v6addrs.dst);
 562         default:
 563                 return 0;
 564         }
 565 }
 566 EXPORT_SYMBOL(flow_get_u32_dst);
 567
 568 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 569 {
 570         int addr_diff, i;
 571
 572         switch (keys->control.addr_type) {
 573         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 574                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 575                             (__force u32)keys->addrs.v4addrs.src;
 576                 if ((addr_diff < 0) ||
 577                     (addr_diff == 0 &&
 578                      ((__force u16)keys->ports.dst <
 579                       (__force u16)keys->ports.src))) {
 580                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 581                         swap(keys->ports.src, keys->ports.dst);
 582                 }
 583                 break;
 584         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 585                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 586                                    &keys->addrs.v6addrs.src,
 587                                    sizeof(keys->addrs.v6addrs.dst));
 588                 if ((addr_diff < 0) ||
 589                     (addr_diff == 0 &&
 590                      ((__force u16)keys->ports.dst <
 591                       (__force u16)keys->ports.src))) {
 592                         for (i = 0; i < 4; i++)
 593                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 594                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 595                         swap(keys->ports.src, keys->ports.dst);
 596                 }
 597                 break;
 598         }
 599 }
 600
 601 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 602 {
 603         u32 hash;
 604
 605         __flow_hash_consistentify(keys);
 606
 607         hash = __flow_hash_words(flow_keys_hash_start(keys),
 608                                  flow_keys_hash_length(keys), keyval);
 609         if (!hash)
 610                 hash = 1;
 611
 612         return hash;
 613 }
 614
 615 u32 flow_hash_from_keys(struct flow_keys *keys)
 616 {
 617         __flow_hash_secret_init();
 618         return __flow_hash_from_keys(keys, hashrnd);
 619 }
 620 EXPORT_SYMBOL(flow_hash_from_keys);
 621
 622 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 623                                   struct flow_keys *keys, u32 keyval)
 624 {
 625         skb_flow_dissect_flow_keys(skb, keys,
 626                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 627
 628         return __flow_hash_from_keys(keys, keyval);
 629 }
 630
 631 struct _flow_keys_digest_data {
 632         __be16  n_proto;
 633         u8      ip_proto;
 634         u8      padding;
 635         __be32  ports;
 636         __be32  src;
 637         __be32  dst;
 638 };
 639
 640 void make_flow_keys_digest(struct flow_keys_digest *digest,
 641                            const struct flow_keys *flow)
 642 {
 643         struct _flow_keys_digest_data *data =
 644             (struct _flow_keys_digest_data *)digest;
 645
 646         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 647
 648         memset(digest, 0, sizeof(*digest));
 649
 650         data->n_proto = flow->basic.n_proto;
 651         data->ip_proto = flow->basic.ip_proto;
 652         data->ports = flow->ports.ports;
 653         data->src = flow->addrs.v4addrs.src;
 654         data->dst = flow->addrs.v4addrs.dst;
 655 }
 656 EXPORT_SYMBOL(make_flow_keys_digest);
 657
 658 /**
 659  * __skb_get_hash: calculate a flow hash
 660  * @skb: sk_buff to calculate flow hash from
 661  *
 662  * This function calculates a flow hash based on src/dst addresses
 663  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 664  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 665  * if hash is a canonical 4-tuple hash over transport ports.
 666  */
 667 void __skb_get_hash(struct sk_buff *skb)
 668 {
 669         struct flow_keys keys;
 670
 671         __flow_hash_secret_init();
 672
 673         __skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd),
 674                           flow_keys_have_l4(&keys));
 675 }
 676 EXPORT_SYMBOL(__skb_get_hash);
 677
 678 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 679 {
 680         struct flow_keys keys;
 681
 682         return ___skb_get_hash(skb, &keys, perturb);
 683 }
 684 EXPORT_SYMBOL(skb_get_hash_perturb);
 685
 686 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 687 {
 688         struct flow_keys keys;
 689
 690         memset(&keys, 0, sizeof(keys));
 691
 692         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 693                sizeof(keys.addrs.v6addrs.src));
 694         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 695                sizeof(keys.addrs.v6addrs.dst));
 696         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 697         keys.ports.src = fl6->fl6_sport;
 698         keys.ports.dst = fl6->fl6_dport;
 699         keys.keyid.keyid = fl6->fl6_gre_key;
 700         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 701         keys.basic.ip_proto = fl6->flowi6_proto;
 702
 703         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 704                           flow_keys_have_l4(&keys));
 705
 706         return skb->hash;
 707 }
 708 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 709
 710 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 711 {
 712         struct flow_keys keys;
 713
 714         memset(&keys, 0, sizeof(keys));
 715
 716         keys.addrs.v4addrs.src = fl4->saddr;
 717         keys.addrs.v4addrs.dst = fl4->daddr;
 718         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 719         keys.ports.src = fl4->fl4_sport;
 720         keys.ports.dst = fl4->fl4_dport;
 721         keys.keyid.keyid = fl4->fl4_gre_key;
 722         keys.basic.ip_proto = fl4->flowi4_proto;
 723
 724         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 725                           flow_keys_have_l4(&keys));
 726
 727         return skb->hash;
 728 }
 729 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 730
 731 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 732                    const struct flow_keys *keys, int hlen)
 733 {
 734         u32 poff = keys->control.thoff;
 735
 736         switch (keys->basic.ip_proto) {
 737         case IPPROTO_TCP: {
 738                 /* access doff as u8 to avoid unaligned access */
 739                 const u8 *doff;
 740                 u8 _doff;
 741
 742                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 743                                             data, hlen, &_doff);
 744                 if (!doff)
 745                         return poff;
 746
 747                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 748                 break;
 749         }
 750         case IPPROTO_UDP:
 751         case IPPROTO_UDPLITE:
 752                 poff += sizeof(struct udphdr);
 753                 break;
 754         /* For the rest, we do not really care about header
 755          * extensions at this point for now.
 756          */
 757         case IPPROTO_ICMP:
 758                 poff += sizeof(struct icmphdr);
 759                 break;
 760         case IPPROTO_ICMPV6:
 761                 poff += sizeof(struct icmp6hdr);
 762                 break;
 763         case IPPROTO_IGMP:
 764                 poff += sizeof(struct igmphdr);
 765                 break;
 766         case IPPROTO_DCCP:
 767                 poff += sizeof(struct dccp_hdr);
 768                 break;
 769         case IPPROTO_SCTP:
 770                 poff += sizeof(struct sctphdr);
 771                 break;
 772         }
 773
 774         return poff;
 775 }
 776
 777 /**
 778  * skb_get_poff - get the offset to the payload
 779  * @skb: sk_buff to get the payload offset from
 780  *
 781  * The function will get the offset to the payload as far as it could
 782  * be dissected.  The main user is currently BPF, so that we can dynamically
 783  * truncate packets without needing to push actual payload to the user
 784  * space and can analyze headers only, instead.
 785  */
 786 u32 skb_get_poff(const struct sk_buff *skb)
 787 {
 788         struct flow_keys keys;
 789
 790         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 791                 return 0;
 792
 793         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 794 }
 795
 796 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 797 {
 798         memset(keys, 0, sizeof(*keys));
 799
 800         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 801             sizeof(keys->addrs.v6addrs.src));
 802         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 803             sizeof(keys->addrs.v6addrs.dst));
 804         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 805         keys->ports.src = fl6->fl6_sport;
 806         keys->ports.dst = fl6->fl6_dport;
 807         keys->keyid.keyid = fl6->fl6_gre_key;
 808         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 809         keys->basic.ip_proto = fl6->flowi6_proto;
 810
 811         return flow_hash_from_keys(keys);
 812 }
 813 EXPORT_SYMBOL(__get_hash_from_flowi6);
 814
 815 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 816 {
 817         memset(keys, 0, sizeof(*keys));
 818
 819         keys->addrs.v4addrs.src = fl4->saddr;
 820         keys->addrs.v4addrs.dst = fl4->daddr;
 821         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 822         keys->ports.src = fl4->fl4_sport;
 823         keys->ports.dst = fl4->fl4_dport;
 824         keys->keyid.keyid = fl4->fl4_gre_key;
 825         keys->basic.ip_proto = fl4->flowi4_proto;
 826
 827         return flow_hash_from_keys(keys);
 828 }
 829 EXPORT_SYMBOL(__get_hash_from_flowi4);
 830
 831 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 832         {
 833                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 834                 .offset = offsetof(struct flow_keys, control),
 835         },
 836         {
 837                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 838                 .offset = offsetof(struct flow_keys, basic),
 839         },
 840         {
 841                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 842                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 843         },
 844         {
 845                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 846                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 847         },
 848         {
 849                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 850                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 851         },
 852         {
 853                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 854                 .offset = offsetof(struct flow_keys, ports),
 855         },
 856         {
 857                 .key_id = FLOW_DISSECTOR_KEY_VLANID,
 858                 .offset = offsetof(struct flow_keys, tags),
 859         },
 860         {
 861                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 862                 .offset = offsetof(struct flow_keys, tags),
 863         },
 864         {
 865                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 866                 .offset = offsetof(struct flow_keys, keyid),
 867         },
 868 };
 869
 870 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 871         {
 872                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 873                 .offset = offsetof(struct flow_keys, control),
 874         },
 875         {
 876                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 877                 .offset = offsetof(struct flow_keys, basic),
 878         },
 879 };
 880
 881 struct flow_dissector flow_keys_dissector __read_mostly;
 882 EXPORT_SYMBOL(flow_keys_dissector);
 883
 884 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 885
 886 static int __init init_default_flow_dissectors(void)
 887 {
 888         skb_flow_dissector_init(&flow_keys_dissector,
 889                                 flow_keys_dissector_keys,
 890                                 ARRAY_SIZE(flow_keys_dissector_keys));
 891         skb_flow_dissector_init(&flow_keys_buf_dissector,
 892                                 flow_keys_buf_dissector_keys,
 893                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
 894         return 0;
 895 }
 896
 897 late_initcall_sync(init_default_flow_dissectors);