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 skb_flow_dissector_uses_key(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 skb_flow_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(skb_flow_dissector_uses_key(flow_dissector,
  55                                                    key->key_id));
  56
  57                 skb_flow_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(!skb_flow_dissector_uses_key(flow_dissector,
  65                                             FLOW_DISSECTOR_KEY_CONTROL));
  66         BUG_ON(!skb_flow_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 (skb_flow_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 (!skb_flow_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->is_fragment = 1;
 193
 194                         if (iph->frag_off & htons(IP_OFFSET)) {
 195                                 goto out_good;
 196                         } else {
 197                                 key_control->first_frag = 1;
 198                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
 199                                         goto out_good;
 200                         }
 201                 }
 202
 203                 break;
 204         }
 205         case htons(ETH_P_IPV6): {
 206                 const struct ipv6hdr *iph;
 207                 struct ipv6hdr _iph;
 208                 __be32 flow_label;
 209
 210 ipv6:
 211                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 212                 if (!iph)
 213                         goto out_bad;
 214
 215                 ip_proto = iph->nexthdr;
 216                 nhoff += sizeof(struct ipv6hdr);
 217
 218                 if (skb_flow_dissector_uses_key(flow_dissector,
 219                                                 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 220                         struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs;
 221
 222                         key_ipv6_addrs = skb_flow_dissector_target(flow_dissector,
 223                                                                    FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 224                                                                    target_container);
 225
 226                         memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
 227                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 228                 }
 229
 230                 flow_label = ip6_flowlabel(iph);
 231                 if (flow_label) {
 232                         if (skb_flow_dissector_uses_key(flow_dissector,
 233                                 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 234                                 key_tags = skb_flow_dissector_target(flow_dissector,
 235                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 236                                                                      target_container);
 237                                 key_tags->flow_label = ntohl(flow_label);
 238                         }
 239                 }
 240
 241                 break;
 242         }
 243         case htons(ETH_P_8021AD):
 244         case htons(ETH_P_8021Q): {
 245                 const struct vlan_hdr *vlan;
 246                 struct vlan_hdr _vlan;
 247
 248                 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
 249                 if (!vlan)
 250                         goto out_bad;
 251
 252                 if (skb_flow_dissector_uses_key(flow_dissector,
 253                                                 FLOW_DISSECTOR_KEY_VLANID)) {
 254                         key_tags = skb_flow_dissector_target(flow_dissector,
 255                                                              FLOW_DISSECTOR_KEY_VLANID,
 256                                                              target_container);
 257
 258                         key_tags->vlan_id = skb_vlan_tag_get_id(skb);
 259                 }
 260
 261                 proto = vlan->h_vlan_encapsulated_proto;
 262                 nhoff += sizeof(*vlan);
 263                 goto again;
 264         }
 265         case htons(ETH_P_PPP_SES): {
 266                 struct {
 267                         struct pppoe_hdr hdr;
 268                         __be16 proto;
 269                 } *hdr, _hdr;
 270                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 271                 if (!hdr)
 272                         goto out_bad;
 273                 proto = hdr->proto;
 274                 nhoff += PPPOE_SES_HLEN;
 275                 switch (proto) {
 276                 case htons(PPP_IP):
 277                         goto ip;
 278                 case htons(PPP_IPV6):
 279                         goto ipv6;
 280                 default:
 281                         goto out_bad;
 282                 }
 283         }
 284         case htons(ETH_P_TIPC): {
 285                 struct {
 286                         __be32 pre[3];
 287                         __be32 srcnode;
 288                 } *hdr, _hdr;
 289                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 290                 if (!hdr)
 291                         goto out_bad;
 292
 293                 if (skb_flow_dissector_uses_key(flow_dissector,
 294                                                 FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 295                         key_addrs = skb_flow_dissector_target(flow_dissector,
 296                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 297                                                               target_container);
 298                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 299                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 300                 }
 301                 goto out_good;
 302         }
 303
 304         case htons(ETH_P_MPLS_UC):
 305         case htons(ETH_P_MPLS_MC): {
 306                 struct mpls_label *hdr, _hdr[2];
 307 mpls:
 308                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 309                                            hlen, &_hdr);
 310                 if (!hdr)
 311                         goto out_bad;
 312
 313                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 314                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 315                         if (skb_flow_dissector_uses_key(flow_dissector,
 316                                                         FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 317                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 318                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 319                                                                       target_container);
 320                                 key_keyid->keyid = hdr[1].entry &
 321                                         htonl(MPLS_LS_LABEL_MASK);
 322                         }
 323
 324                         goto out_good;
 325                 }
 326
 327                 goto out_good;
 328         }
 329
 330         case htons(ETH_P_FCOE):
 331                 key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
 332                 /* fall through */
 333         default:
 334                 goto out_bad;
 335         }
 336
 337 ip_proto_again:
 338         switch (ip_proto) {
 339         case IPPROTO_GRE: {
 340                 struct gre_hdr {
 341                         __be16 flags;
 342                         __be16 proto;
 343                 } *hdr, _hdr;
 344
 345                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 346                 if (!hdr)
 347                         goto out_bad;
 348                 /*
 349                  * Only look inside GRE if version zero and no
 350                  * routing
 351                  */
 352                 if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
 353                         break;
 354
 355                 proto = hdr->proto;
 356                 nhoff += 4;
 357                 if (hdr->flags & GRE_CSUM)
 358                         nhoff += 4;
 359                 if (hdr->flags & GRE_KEY) {
 360                         const __be32 *keyid;
 361                         __be32 _keyid;
 362
 363                         keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
 364                                                      data, hlen, &_keyid);
 365
 366                         if (!keyid)
 367                                 goto out_bad;
 368
 369                         if (skb_flow_dissector_uses_key(flow_dissector,
 370                                                         FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 371                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 372                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 373                                                                       target_container);
 374                                 key_keyid->keyid = *keyid;
 375                         }
 376                         nhoff += 4;
 377                 }
 378                 if (hdr->flags & GRE_SEQ)
 379                         nhoff += 4;
 380                 if (proto == htons(ETH_P_TEB)) {
 381                         const struct ethhdr *eth;
 382                         struct ethhdr _eth;
 383
 384                         eth = __skb_header_pointer(skb, nhoff,
 385                                                    sizeof(_eth),
 386                                                    data, hlen, &_eth);
 387                         if (!eth)
 388                                 goto out_bad;
 389                         proto = eth->h_proto;
 390                         nhoff += sizeof(*eth);
 391                 }
 392                 goto again;
 393         }
 394         case NEXTHDR_HOP:
 395         case NEXTHDR_ROUTING:
 396         case NEXTHDR_DEST: {
 397                 u8 _opthdr[2], *opthdr;
 398
 399                 if (proto != htons(ETH_P_IPV6))
 400                         break;
 401
 402                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 403                                               data, hlen, &_opthdr);
 404                 if (!opthdr)
 405                         goto out_bad;
 406
 407                 ip_proto = opthdr[0];
 408                 nhoff += (opthdr[1] + 1) << 3;
 409
 410                 goto ip_proto_again;
 411         }
 412         case IPPROTO_IPIP:
 413                 proto = htons(ETH_P_IP);
 414                 goto ip;
 415         case IPPROTO_IPV6:
 416                 proto = htons(ETH_P_IPV6);
 417                 goto ipv6;
 418         case IPPROTO_MPLS:
 419                 proto = htons(ETH_P_MPLS_UC);
 420                 goto mpls;
 421         default:
 422                 break;
 423         }
 424
 425         if (skb_flow_dissector_uses_key(flow_dissector,
 426                                         FLOW_DISSECTOR_KEY_PORTS)) {
 427                 key_ports = skb_flow_dissector_target(flow_dissector,
 428                                                       FLOW_DISSECTOR_KEY_PORTS,
 429                                                       target_container);
 430                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 431                                                         data, hlen);
 432         }
 433
 434 out_good:
 435         ret = true;
 436
 437 out_bad:
 438         key_basic->n_proto = proto;
 439         key_basic->ip_proto = ip_proto;
 440         key_control->thoff = (u16)nhoff;
 441
 442         return ret;
 443 }
 444 EXPORT_SYMBOL(__skb_flow_dissect);
 445
 446 static u32 hashrnd __read_mostly;
 447 static __always_inline void __flow_hash_secret_init(void)
 448 {
 449         net_get_random_once(&hashrnd, sizeof(hashrnd));
 450 }
 451
 452 static __always_inline u32 __flow_hash_words(u32 *words, u32 length, u32 keyval)
 453 {
 454         return jhash2(words, length, keyval);
 455 }
 456
 457 static inline void *flow_keys_hash_start(struct flow_keys *flow)
 458 {
 459         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 460         return (void *)flow + FLOW_KEYS_HASH_OFFSET;
 461 }
 462
 463 static inline size_t flow_keys_hash_length(struct flow_keys *flow)
 464 {
 465         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 466         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 467         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 468                      sizeof(*flow) - sizeof(flow->addrs));
 469
 470         switch (flow->control.addr_type) {
 471         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 472                 diff -= sizeof(flow->addrs.v4addrs);
 473                 break;
 474         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 475                 diff -= sizeof(flow->addrs.v6addrs);
 476                 break;
 477         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 478                 diff -= sizeof(flow->addrs.tipcaddrs);
 479                 break;
 480         }
 481         return (sizeof(*flow) - diff) / sizeof(u32);
 482 }
 483
 484 __be32 flow_get_u32_src(const struct flow_keys *flow)
 485 {
 486         switch (flow->control.addr_type) {
 487         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 488                 return flow->addrs.v4addrs.src;
 489         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 490                 return (__force __be32)ipv6_addr_hash(
 491                         &flow->addrs.v6addrs.src);
 492         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 493                 return flow->addrs.tipcaddrs.srcnode;
 494         default:
 495                 return 0;
 496         }
 497 }
 498 EXPORT_SYMBOL(flow_get_u32_src);
 499
 500 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 501 {
 502         switch (flow->control.addr_type) {
 503         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 504                 return flow->addrs.v4addrs.dst;
 505         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 506                 return (__force __be32)ipv6_addr_hash(
 507                         &flow->addrs.v6addrs.dst);
 508         default:
 509                 return 0;
 510         }
 511 }
 512 EXPORT_SYMBOL(flow_get_u32_dst);
 513
 514 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 515 {
 516         int addr_diff, i;
 517
 518         switch (keys->control.addr_type) {
 519         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 520                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 521                             (__force u32)keys->addrs.v4addrs.src;
 522                 if ((addr_diff < 0) ||
 523                     (addr_diff == 0 &&
 524                      ((__force u16)keys->ports.dst <
 525                       (__force u16)keys->ports.src))) {
 526                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 527                         swap(keys->ports.src, keys->ports.dst);
 528                 }
 529                 break;
 530         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 531                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 532                                    &keys->addrs.v6addrs.src,
 533                                    sizeof(keys->addrs.v6addrs.dst));
 534                 if ((addr_diff < 0) ||
 535                     (addr_diff == 0 &&
 536                      ((__force u16)keys->ports.dst <
 537                       (__force u16)keys->ports.src))) {
 538                         for (i = 0; i < 4; i++)
 539                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 540                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 541                         swap(keys->ports.src, keys->ports.dst);
 542                 }
 543                 break;
 544         }
 545 }
 546
 547 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 548 {
 549         u32 hash;
 550
 551         __flow_hash_consistentify(keys);
 552
 553         hash = __flow_hash_words((u32 *)flow_keys_hash_start(keys),
 554                                  flow_keys_hash_length(keys), keyval);
 555         if (!hash)
 556                 hash = 1;
 557
 558         return hash;
 559 }
 560
 561 u32 flow_hash_from_keys(struct flow_keys *keys)
 562 {
 563         __flow_hash_secret_init();
 564         return __flow_hash_from_keys(keys, hashrnd);
 565 }
 566 EXPORT_SYMBOL(flow_hash_from_keys);
 567
 568 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 569                                   struct flow_keys *keys, u32 keyval)
 570 {
 571         if (!skb_flow_dissect_flow_keys(skb, keys, 0))
 572                 return 0;
 573
 574         return __flow_hash_from_keys(keys, keyval);
 575 }
 576
 577 struct _flow_keys_digest_data {
 578         __be16  n_proto;
 579         u8      ip_proto;
 580         u8      padding;
 581         __be32  ports;
 582         __be32  src;
 583         __be32  dst;
 584 };
 585
 586 void make_flow_keys_digest(struct flow_keys_digest *digest,
 587                            const struct flow_keys *flow)
 588 {
 589         struct _flow_keys_digest_data *data =
 590             (struct _flow_keys_digest_data *)digest;
 591
 592         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 593
 594         memset(digest, 0, sizeof(*digest));
 595
 596         data->n_proto = flow->basic.n_proto;
 597         data->ip_proto = flow->basic.ip_proto;
 598         data->ports = flow->ports.ports;
 599         data->src = flow->addrs.v4addrs.src;
 600         data->dst = flow->addrs.v4addrs.dst;
 601 }
 602 EXPORT_SYMBOL(make_flow_keys_digest);
 603
 604 /**
 605  * __skb_get_hash: calculate a flow hash
 606  * @skb: sk_buff to calculate flow hash from
 607  *
 608  * This function calculates a flow hash based on src/dst addresses
 609  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 610  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 611  * if hash is a canonical 4-tuple hash over transport ports.
 612  */
 613 void __skb_get_hash(struct sk_buff *skb)
 614 {
 615         struct flow_keys keys;
 616         u32 hash;
 617
 618         __flow_hash_secret_init();
 619
 620         hash = ___skb_get_hash(skb, &keys, hashrnd);
 621         if (!hash)
 622                 return;
 623
 624         __skb_set_sw_hash(skb, hash,
 625                           flow_keys_have_l4(&keys));
 626 }
 627 EXPORT_SYMBOL(__skb_get_hash);
 628
 629 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 630 {
 631         struct flow_keys keys;
 632
 633         return ___skb_get_hash(skb, &keys, perturb);
 634 }
 635 EXPORT_SYMBOL(skb_get_hash_perturb);
 636
 637 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, struct flowi6 *fl6)
 638 {
 639         struct flow_keys keys;
 640
 641         memset(&keys, 0, sizeof(keys));
 642
 643         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
 644                sizeof(keys.addrs.v6addrs.src));
 645         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
 646                sizeof(keys.addrs.v6addrs.dst));
 647         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 648         keys.ports.src = fl6->fl6_sport;
 649         keys.ports.dst = fl6->fl6_dport;
 650         keys.keyid.keyid = fl6->fl6_gre_key;
 651         keys.tags.flow_label = (__force u32)fl6->flowlabel;
 652         keys.basic.ip_proto = fl6->flowi6_proto;
 653
 654         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 655                           flow_keys_have_l4(&keys));
 656
 657         return skb->hash;
 658 }
 659 EXPORT_SYMBOL(__skb_get_hash_flowi6);
 660
 661 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, struct flowi4 *fl4)
 662 {
 663         struct flow_keys keys;
 664
 665         memset(&keys, 0, sizeof(keys));
 666
 667         keys.addrs.v4addrs.src = fl4->saddr;
 668         keys.addrs.v4addrs.dst = fl4->daddr;
 669         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 670         keys.ports.src = fl4->fl4_sport;
 671         keys.ports.dst = fl4->fl4_dport;
 672         keys.keyid.keyid = fl4->fl4_gre_key;
 673         keys.basic.ip_proto = fl4->flowi4_proto;
 674
 675         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
 676                           flow_keys_have_l4(&keys));
 677
 678         return skb->hash;
 679 }
 680 EXPORT_SYMBOL(__skb_get_hash_flowi4);
 681
 682 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 683                    const struct flow_keys *keys, int hlen)
 684 {
 685         u32 poff = keys->control.thoff;
 686
 687         switch (keys->basic.ip_proto) {
 688         case IPPROTO_TCP: {
 689                 /* access doff as u8 to avoid unaligned access */
 690                 const u8 *doff;
 691                 u8 _doff;
 692
 693                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
 694                                             data, hlen, &_doff);
 695                 if (!doff)
 696                         return poff;
 697
 698                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
 699                 break;
 700         }
 701         case IPPROTO_UDP:
 702         case IPPROTO_UDPLITE:
 703                 poff += sizeof(struct udphdr);
 704                 break;
 705         /* For the rest, we do not really care about header
 706          * extensions at this point for now.
 707          */
 708         case IPPROTO_ICMP:
 709                 poff += sizeof(struct icmphdr);
 710                 break;
 711         case IPPROTO_ICMPV6:
 712                 poff += sizeof(struct icmp6hdr);
 713                 break;
 714         case IPPROTO_IGMP:
 715                 poff += sizeof(struct igmphdr);
 716                 break;
 717         case IPPROTO_DCCP:
 718                 poff += sizeof(struct dccp_hdr);
 719                 break;
 720         case IPPROTO_SCTP:
 721                 poff += sizeof(struct sctphdr);
 722                 break;
 723         }
 724
 725         return poff;
 726 }
 727
 728 /**
 729  * skb_get_poff - get the offset to the payload
 730  * @skb: sk_buff to get the payload offset from
 731  *
 732  * The function will get the offset to the payload as far as it could
 733  * be dissected.  The main user is currently BPF, so that we can dynamically
 734  * truncate packets without needing to push actual payload to the user
 735  * space and can analyze headers only, instead.
 736  */
 737 u32 skb_get_poff(const struct sk_buff *skb)
 738 {
 739         struct flow_keys keys;
 740
 741         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
 742                 return 0;
 743
 744         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 745 }
 746
 747 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 748         {
 749                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 750                 .offset = offsetof(struct flow_keys, control),
 751         },
 752         {
 753                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 754                 .offset = offsetof(struct flow_keys, basic),
 755         },
 756         {
 757                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 758                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 759         },
 760         {
 761                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 762                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 763         },
 764         {
 765                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 766                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 767         },
 768         {
 769                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 770                 .offset = offsetof(struct flow_keys, ports),
 771         },
 772         {
 773                 .key_id = FLOW_DISSECTOR_KEY_VLANID,
 774                 .offset = offsetof(struct flow_keys, tags),
 775         },
 776         {
 777                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 778                 .offset = offsetof(struct flow_keys, tags),
 779         },
 780         {
 781                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 782                 .offset = offsetof(struct flow_keys, keyid),
 783         },
 784 };
 785
 786 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 787         {
 788                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 789                 .offset = offsetof(struct flow_keys, control),
 790         },
 791         {
 792                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 793                 .offset = offsetof(struct flow_keys, basic),
 794         },
 795 };
 796
 797 struct flow_dissector flow_keys_dissector __read_mostly;
 798 EXPORT_SYMBOL(flow_keys_dissector);
 799
 800 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 801
 802 static int __init init_default_flow_dissectors(void)
 803 {
 804         skb_flow_dissector_init(&flow_keys_dissector,
 805                                 flow_keys_dissector_keys,
 806                                 ARRAY_SIZE(flow_keys_dissector_keys));
 807         skb_flow_dissector_init(&flow_keys_buf_dissector,
 808                                 flow_keys_buf_dissector_keys,
 809                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
 810         return 0;
 811 }
 812
 813 late_initcall_sync(init_default_flow_dissectors);