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;
 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                         key_addrs = skb_flow_dissector_target(flow_dissector,
 184                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 185                                                               target_container);
 186
 187                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 188                                sizeof(key_addrs->v4addrs));
 189                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 190                 }
 191
 192                 if (ip_is_fragment(iph)) {
 193                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 194
 195                         if (iph->frag_off & htons(IP_OFFSET)) {
 196                                 goto out_good;
 197                         } else {
 198                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 199                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 200                                         goto out_good;
 201                         }
 202                 }
 203
 204                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 205                         goto out_good;
 206
 207                 break;
 208         }
 209         case htons(ETH_P_IPV6): {
 210                 const struct ipv6hdr *iph;
 211                 struct ipv6hdr _iph;
 212
 213 ipv6:
 214                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 215                 if (!iph)
 216                         goto out_bad;
 217
 218                 ip_proto = iph->nexthdr;
 219                 nhoff += sizeof(struct ipv6hdr);
 220
 221                 if (dissector_uses_key(flow_dissector,
 222                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 223                         struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs;
 224
 225                         key_ipv6_addrs = skb_flow_dissector_target(flow_dissector,
 226                                                                    FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 227                                                                    target_container);
 228
 229                         memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
 230                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 231                 }
 232
 233                 if ((dissector_uses_key(flow_dissector,
 234                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 235                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 236                     ip6_flowlabel(iph)) {
 237                         __be32 flow_label = ip6_flowlabel(iph);
 238
 239                         if (dissector_uses_key(flow_dissector,
 240                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 241                                 key_tags = skb_flow_dissector_target(flow_dissector,
 242                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 243                                                                      target_container);
 244                                 key_tags->flow_label = ntohl(flow_label);
 245                         }
 246                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 247                                 goto out_good;
 248                 }
 249
 250                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 251                         goto out_good;
 252
 253                 break;
 254         }
 255         case htons(ETH_P_8021AD):
 256         case htons(ETH_P_8021Q): {
 257                 const struct vlan_hdr *vlan;
 258                 struct vlan_hdr _vlan;
 259
 260                 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
 261                 if (!vlan)
 262                         goto out_bad;
 263
 264                 if (dissector_uses_key(flow_dissector,
 265                                        FLOW_DISSECTOR_KEY_VLANID)) {
 266                         key_tags = skb_flow_dissector_target(flow_dissector,
 267                                                              FLOW_DISSECTOR_KEY_VLANID,
 268                                                              target_container);
 269
 270                         key_tags->vlan_id = skb_vlan_tag_get_id(skb);
 271                 }
 272
 273                 proto = vlan->h_vlan_encapsulated_proto;
 274                 nhoff += sizeof(*vlan);
 275                 goto again;
 276         }
 277         case htons(ETH_P_PPP_SES): {
 278                 struct {
 279                         struct pppoe_hdr hdr;
 280                         __be16 proto;
 281                 } *hdr, _hdr;
 282                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 283                 if (!hdr)
 284                         goto out_bad;
 285                 proto = hdr->proto;
 286                 nhoff += PPPOE_SES_HLEN;
 287                 switch (proto) {
 288                 case htons(PPP_IP):
 289                         goto ip;
 290                 case htons(PPP_IPV6):
 291                         goto ipv6;
 292                 default:
 293                         goto out_bad;
 294                 }
 295         }
 296         case htons(ETH_P_TIPC): {
 297                 struct {
 298                         __be32 pre[3];
 299                         __be32 srcnode;
 300                 } *hdr, _hdr;
 301                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 302                 if (!hdr)
 303                         goto out_bad;
 304
 305                 if (dissector_uses_key(flow_dissector,
 306                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 307                         key_addrs = skb_flow_dissector_target(flow_dissector,
 308                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 309                                                               target_container);
 310                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 311                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 312                 }
 313                 goto out_good;
 314         }
 315
 316         case htons(ETH_P_MPLS_UC):
 317         case htons(ETH_P_MPLS_MC): {
 318                 struct mpls_label *hdr, _hdr[2];
 319 mpls:
 320                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 321                                            hlen, &_hdr);
 322                 if (!hdr)
 323                         goto out_bad;
 324
 325                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 326                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 327                         if (dissector_uses_key(flow_dissector,
 328                                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 329                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 330                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 331                                                                       target_container);
 332                                 key_keyid->keyid = hdr[1].entry &
 333                                         htonl(MPLS_LS_LABEL_MASK);
 334                         }
 335
 336                         goto out_good;
 337                 }
 338
 339                 goto out_good;
 340         }
 341
 342         case htons(ETH_P_FCOE):
 343                 key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
 344                 /* fall through */
 345         default:
 346                 goto out_bad;
 347         }
 348
 349 ip_proto_again:
 350         switch (ip_proto) {
 351         case IPPROTO_GRE: {
 352                 struct gre_hdr {
 353                         __be16 flags;
 354                         __be16 proto;
 355                 } *hdr, _hdr;
 356
 357                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 358                 if (!hdr)
 359                         goto out_bad;
 360                 /*
 361                  * Only look inside GRE if version zero and no
 362                  * routing
 363                  */
 364                 if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
 365                         break;
 366
 367                 proto = hdr->proto;
 368                 nhoff += 4;
 369                 if (hdr->flags & GRE_CSUM)
 370                         nhoff += 4;
 371                 if (hdr->flags & GRE_KEY) {
 372                         const __be32 *keyid;
 373                         __be32 _keyid;
 374
 375                         keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
 376                                                      data, hlen, &_keyid);
 377
 378                         if (!keyid)
 379                                 goto out_bad;
 380
 381                         if (dissector_uses_key(flow_dissector,
 382                                                FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 383                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 384                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 385                                                                       target_container);
 386                                 key_keyid->keyid = *keyid;
 387                         }
 388                         nhoff += 4;
 389                 }
 390                 if (hdr->flags & GRE_SEQ)
 391                         nhoff += 4;
 392                 if (proto == htons(ETH_P_TEB)) {
 393                         const struct ethhdr *eth;
 394                         struct ethhdr _eth;
 395
 396                         eth = __skb_header_pointer(skb, nhoff,
 397                                                    sizeof(_eth),
 398                                                    data, hlen, &_eth);
 399                         if (!eth)
 400                                 goto out_bad;
 401                         proto = eth->h_proto;
 402                         nhoff += sizeof(*eth);
 403
 404                         /* Cap headers that we access via pointers at the
 405                          * end of the Ethernet header as our maximum alignment
 406                          * at that point is only 2 bytes.
 407                          */
 408                         if (NET_IP_ALIGN)
 409                                 hlen = nhoff;
 410                 }
 411
 412                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 413                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 414                         goto out_good;
 415
 416                 goto again;
 417         }
 418         case NEXTHDR_HOP:
 419         case NEXTHDR_ROUTING:
 420         case NEXTHDR_DEST: {
 421                 u8 _opthdr[2], *opthdr;
 422
 423                 if (proto != htons(ETH_P_IPV6))
 424                         break;
 425
 426                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 427                                               data, hlen, &_opthdr);
 428                 if (!opthdr)
 429                         goto out_bad;
 430
 431                 ip_proto = opthdr[0];
 432                 nhoff += (opthdr[1] + 1) << 3;
 433
 434                 goto ip_proto_again;
 435         }
 436         case NEXTHDR_FRAGMENT: {
 437                 struct frag_hdr _fh, *fh;
 438
 439                 if (proto != htons(ETH_P_IPV6))
 440                         break;
 441
 442                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 443                                           data, hlen, &_fh);
 444
 445                 if (!fh)
 446                         goto out_bad;
 447
 448                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 449
 450                 nhoff += sizeof(_fh);
 451
 452                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 453                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 454                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 455                                 ip_proto = fh->nexthdr;
 456                                 goto ip_proto_again;
 457                         }
 458                 }
 459                 goto out_good;
 460         }
 461         case IPPROTO_IPIP:
 462                 proto = htons(ETH_P_IP);
 463
 464                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 465                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 466                         goto out_good;
 467
 468                 goto ip;
 469         case IPPROTO_IPV6:
 470                 proto = htons(ETH_P_IPV6);
 471
 472                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 473                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 474                         goto out_good;
 475
 476                 goto ipv6;
 477         case IPPROTO_MPLS:
 478                 proto = htons(ETH_P_MPLS_UC);
 479                 goto mpls;
 480         default:
 481                 break;
 482         }
 483
 484         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
 485             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
 486                 key_ports = skb_flow_dissector_target(flow_dissector,
 487                                                       FLOW_DISSECTOR_KEY_PORTS,
 488                                                       target_container);
 489                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 490                                                         data, hlen);
 491         }
 492
 493 out_good:
 494         ret = true;
 495
 496 out:
 497         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
 498         key_basic->n_proto = proto;
 499         key_basic->ip_proto = ip_proto;
 500
 501         return ret;
 502
 503 out_bad:
 504         ret = false;
 505         goto out;
 506 }
 507 EXPORT_SYMBOL(__skb_flow_dissect);
 508
 509 static siphash_key_t hashrnd __read_mostly;
 510 static __always_inline void __flow_hash_secret_init(void)
 511 {
 512         net_get_random_once(&hashrnd, sizeof(hashrnd));
 513 }
 514
 515 static const void *flow_keys_hash_start(const struct flow_keys *flow)
 516 {
 517         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
 518         return &flow->FLOW_KEYS_HASH_START_FIELD;
 519 }
 520
 521 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
 522 {
 523         size_t len = offsetof(typeof(*flow), addrs) - FLOW_KEYS_HASH_OFFSET;
 524
 525         switch (flow->control.addr_type) {
 526         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 527                 len += sizeof(flow->addrs.v4addrs);
 528                 break;
 529         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 530                 len += sizeof(flow->addrs.v6addrs);
 531                 break;
 532         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 533                 len += sizeof(flow->addrs.tipcaddrs);
 534                 break;
 535         }
 536         return len;
 537 }
 538
 539 __be32 flow_get_u32_src(const struct flow_keys *flow)
 540 {
 541         switch (flow->control.addr_type) {
 542         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 543                 return flow->addrs.v4addrs.src;
 544         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 545                 return (__force __be32)ipv6_addr_hash(
 546                         &flow->addrs.v6addrs.src);
 547         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 548                 return flow->addrs.tipcaddrs.srcnode;
 549         default:
 550                 return 0;
 551         }
 552 }
 553 EXPORT_SYMBOL(flow_get_u32_src);
 554
 555 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 556 {
 557         switch (flow->control.addr_type) {
 558         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 559                 return flow->addrs.v4addrs.dst;
 560         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 561                 return (__force __be32)ipv6_addr_hash(
 562                         &flow->addrs.v6addrs.dst);
 563         default:
 564                 return 0;
 565         }
 566 }
 567 EXPORT_SYMBOL(flow_get_u32_dst);
 568
 569 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 570 {
 571         int addr_diff, i;
 572
 573         switch (keys->control.addr_type) {
 574         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 575                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 576                             (__force u32)keys->addrs.v4addrs.src;
 577                 if ((addr_diff < 0) ||
 578                     (addr_diff == 0 &&
 579                      ((__force u16)keys->ports.dst <
 580                       (__force u16)keys->ports.src))) {
 581                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 582                         swap(keys->ports.src, keys->ports.dst);
 583                 }
 584                 break;
 585         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 586                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 587                                    &keys->addrs.v6addrs.src,
 588                                    sizeof(keys->addrs.v6addrs.dst));
 589                 if ((addr_diff < 0) ||
 590                     (addr_diff == 0 &&
 591                      ((__force u16)keys->ports.dst <
 592                       (__force u16)keys->ports.src))) {
 593                         for (i = 0; i < 4; i++)
 594                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 595                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 596                         swap(keys->ports.src, keys->ports.dst);
 597                 }
 598                 break;
 599         }
 600 }
 601
 602 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
 603                                         const siphash_key_t *keyval)
 604 {
 605         u32 hash;
 606
 607         __flow_hash_consistentify(keys);
 608
 609         hash = siphash(flow_keys_hash_start(keys),
 610                        flow_keys_hash_length(keys), keyval);
 611         if (!hash)
 612                 hash = 1;
 613
 614         return hash;
 615 }
 616
 617 u32 flow_hash_from_keys(struct flow_keys *keys)
 618 {
 619         __flow_hash_secret_init();
 620         return __flow_hash_from_keys(keys, &hashrnd);
 621 }
 622 EXPORT_SYMBOL(flow_hash_from_keys);
 623
 624 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 625                                   struct flow_keys *keys,
 626                                   const siphash_key_t *keyval)
 627 {
 628         skb_flow_dissect_flow_keys(skb, keys,
 629                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 630
 631         return __flow_hash_from_keys(keys, keyval);
 632 }
 633
 634 struct _flow_keys_digest_data {
 635         __be16  n_proto;
 636         u8      ip_proto;
 637         u8      padding;
 638         __be32  ports;
 639         __be32  src;
 640         __be32  dst;
 641 };
 642
 643 void make_flow_keys_digest(struct flow_keys_digest *digest,
 644                            const struct flow_keys *flow)
 645 {
 646         struct _flow_keys_digest_data *data =
 647             (struct _flow_keys_digest_data *)digest;
 648
 649         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 650
 651         memset(digest, 0, sizeof(*digest));
 652
 653         data->n_proto = flow->basic.n_proto;
 654         data->ip_proto = flow->basic.ip_proto;
 655         data->ports = flow->ports.ports;
 656         data->src = flow->addrs.v4addrs.src;
 657         data->dst = flow->addrs.v4addrs.dst;
 658 }
 659 EXPORT_SYMBOL(make_flow_keys_digest);
 660
 661 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
 662
 663 u32 __skb_get_hash_symmetric(struct sk_buff *skb)
 664 {
 665         struct flow_keys keys;
 666
 667         __flow_hash_secret_init();
 668
 669         memset(&keys, 0, sizeof(keys));
 670         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
 671                            NULL, 0, 0, 0,
 672                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 673
 674         return __flow_hash_from_keys(&keys, &hashrnd);
 675 }
 676 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
 677
 678 /**
 679  * __skb_get_hash: calculate a flow hash
 680  * @skb: sk_buff to calculate flow hash from
 681  *
 682  * This function calculates a flow hash based on src/dst addresses
 683  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 684  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 685  * if hash is a canonical 4-tuple hash over transport ports.
 686  */
 687 void __skb_get_hash(struct sk_buff *skb)
 688 {
 689         struct flow_keys keys;
 690
 691         __flow_hash_secret_init();
 692
 693         __skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, &hashrnd),
 694                           flow_keys_have_l4(&keys));
 695 }
 696 EXPORT_SYMBOL(__skb_get_hash);
 697
 698 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
 699                            const siphash_key_t *perturb)
 700 {
 701         struct flow_keys keys;
 702
 703         return ___skb_get_hash(skb, &keys, perturb);
 704 }
 705 EXPORT_SYMBOL(skb_get_hash_perturb);
 706
 707 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
 708 {
 709         struct flow_keys keys;
 710
 711         memset(&keys, 0, sizeof(keys));
 712
 713         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 714                sizeof(keys.addrs.v6addrs.src));
 715         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 716                sizeof(keys.addrs.v6addrs.dst));
 717         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 718         keys.ports.src = fl6->fl6_sport;
 719         keys.ports.dst = fl6->fl6_dport;
 720         keys.keyid.keyid = fl6->fl6_gre_key;
 721         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 722         keys.basic.ip_proto = fl6->flowi6_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_flowi6);
 730
 731 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
 732 {
 733         struct flow_keys keys;
 734
 735         memset(&keys, 0, sizeof(keys));
 736
 737         keys.addrs.v4addrs.src = fl4->saddr;
 738         keys.addrs.v4addrs.dst = fl4->daddr;
 739         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 740         keys.ports.src = fl4->fl4_sport;
 741         keys.ports.dst = fl4->fl4_dport;
 742         keys.keyid.keyid = fl4->fl4_gre_key;
 743         keys.basic.ip_proto = fl4->flowi4_proto;
 744
 745         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 746                           flow_keys_have_l4(&keys));
 747
 748         return skb->hash;
 749 }
 750 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 751
 752 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 753                    const struct flow_keys *keys, int hlen)
 754 {
 755         u32 poff = keys->control.thoff;
 756
 757         switch (keys->basic.ip_proto) {
 758         case IPPROTO_TCP: {
 759                 /* access doff as u8 to avoid unaligned access */
 760                 const u8 *doff;
 761                 u8 _doff;
 762
 763                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 764                                             data, hlen, &_doff);
 765                 if (!doff)
 766                         return poff;
 767
 768                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 769                 break;
 770         }
 771         case IPPROTO_UDP:
 772         case IPPROTO_UDPLITE:
 773                 poff += sizeof(struct udphdr);
 774                 break;
 775         /* For the rest, we do not really care about header
 776          * extensions at this point for now.
 777          */
 778         case IPPROTO_ICMP:
 779                 poff += sizeof(struct icmphdr);
 780                 break;
 781         case IPPROTO_ICMPV6:
 782                 poff += sizeof(struct icmp6hdr);
 783                 break;
 784         case IPPROTO_IGMP:
 785                 poff += sizeof(struct igmphdr);
 786                 break;
 787         case IPPROTO_DCCP:
 788                 poff += sizeof(struct dccp_hdr);
 789                 break;
 790         case IPPROTO_SCTP:
 791                 poff += sizeof(struct sctphdr);
 792                 break;
 793         }
 794
 795         return poff;
 796 }
 797
 798 /**
 799  * skb_get_poff - get the offset to the payload
 800  * @skb: sk_buff to get the payload offset from
 801  *
 802  * The function will get the offset to the payload as far as it could
 803  * be dissected.  The main user is currently BPF, so that we can dynamically
 804  * truncate packets without needing to push actual payload to the user
 805  * space and can analyze headers only, instead.
 806  */
 807 u32 skb_get_poff(const struct sk_buff *skb)
 808 {
 809         struct flow_keys keys;
 810
 811         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 812                 return 0;
 813
 814         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 815 }
 816
 817 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
 818 {
 819         memset(keys, 0, sizeof(*keys));
 820
 821         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
 822             sizeof(keys->addrs.v6addrs.src));
 823         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
 824             sizeof(keys->addrs.v6addrs.dst));
 825         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 826         keys->ports.src = fl6->fl6_sport;
 827         keys->ports.dst = fl6->fl6_dport;
 828         keys->keyid.keyid = fl6->fl6_gre_key;
 829         keys->tags.flow_label = (__force u32)fl6->flowlabel;
 830         keys->basic.ip_proto = fl6->flowi6_proto;
 831
 832         return flow_hash_from_keys(keys);
 833 }
 834 EXPORT_SYMBOL(__get_hash_from_flowi6);
 835
 836 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
 837 {
 838         memset(keys, 0, sizeof(*keys));
 839
 840         keys->addrs.v4addrs.src = fl4->saddr;
 841         keys->addrs.v4addrs.dst = fl4->daddr;
 842         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 843         keys->ports.src = fl4->fl4_sport;
 844         keys->ports.dst = fl4->fl4_dport;
 845         keys->keyid.keyid = fl4->fl4_gre_key;
 846         keys->basic.ip_proto = fl4->flowi4_proto;
 847
 848         return flow_hash_from_keys(keys);
 849 }
 850 EXPORT_SYMBOL(__get_hash_from_flowi4);
 851
 852 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 853         {
 854                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 855                 .offset = offsetof(struct flow_keys, control),
 856         },
 857         {
 858                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 859                 .offset = offsetof(struct flow_keys, basic),
 860         },
 861         {
 862                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 863                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 864         },
 865         {
 866                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 867                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 868         },
 869         {
 870                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 871                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 872         },
 873         {
 874                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 875                 .offset = offsetof(struct flow_keys, ports),
 876         },
 877         {
 878                 .key_id = FLOW_DISSECTOR_KEY_VLANID,
 879                 .offset = offsetof(struct flow_keys, tags),
 880         },
 881         {
 882                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 883                 .offset = offsetof(struct flow_keys, tags),
 884         },
 885         {
 886                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 887                 .offset = offsetof(struct flow_keys, keyid),
 888         },
 889 };
 890
 891 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
 892         {
 893                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 894                 .offset = offsetof(struct flow_keys, control),
 895         },
 896         {
 897                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 898                 .offset = offsetof(struct flow_keys, basic),
 899         },
 900         {
 901                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 902                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 903         },
 904         {
 905                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 906                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 907         },
 908         {
 909                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 910                 .offset = offsetof(struct flow_keys, ports),
 911         },
 912 };
 913
 914 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 915         {
 916                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 917                 .offset = offsetof(struct flow_keys, control),
 918         },
 919         {
 920                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 921                 .offset = offsetof(struct flow_keys, basic),
 922         },
 923 };
 924
 925 struct flow_dissector flow_keys_dissector __read_mostly;
 926 EXPORT_SYMBOL(flow_keys_dissector);
 927
 928 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 929
 930 static int __init init_default_flow_dissectors(void)
 931 {
 932         skb_flow_dissector_init(&flow_keys_dissector,
 933                                 flow_keys_dissector_keys,
 934                                 ARRAY_SIZE(flow_keys_dissector_keys));
 935         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
 936                                 flow_keys_dissector_symmetric_keys,
 937                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
 938         skb_flow_dissector_init(&flow_keys_buf_dissector,
 939                                 flow_keys_buf_dissector_keys,
 940                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
 941         return 0;
 942 }
 943
 944 core_initcall(init_default_flow_dissectors);