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                 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                 __be32 flow_label;
 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 (skb_flow_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                 flow_label = ip6_flowlabel(iph);
 234                 if (flow_label) {
 235                         if (skb_flow_dissector_uses_key(flow_dissector,
 236                                 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 237                                 key_tags = skb_flow_dissector_target(flow_dissector,
 238                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 239                                                                      target_container);
 240                                 key_tags->flow_label = ntohl(flow_label);
 241                         }
 242                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
 243                                 goto out_good;
 244                 }
 245
 246                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 247                         goto out_good;
 248
 249                 break;
 250         }
 251         case htons(ETH_P_8021AD):
 252         case htons(ETH_P_8021Q): {
 253                 const struct vlan_hdr *vlan;
 254                 struct vlan_hdr _vlan;
 255
 256                 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
 257                 if (!vlan)
 258                         goto out_bad;
 259
 260                 if (skb_flow_dissector_uses_key(flow_dissector,
 261                                                 FLOW_DISSECTOR_KEY_VLANID)) {
 262                         key_tags = skb_flow_dissector_target(flow_dissector,
 263                                                              FLOW_DISSECTOR_KEY_VLANID,
 264                                                              target_container);
 265
 266                         key_tags->vlan_id = skb_vlan_tag_get_id(skb);
 267                 }
 268
 269                 proto = vlan->h_vlan_encapsulated_proto;
 270                 nhoff += sizeof(*vlan);
 271                 goto again;
 272         }
 273         case htons(ETH_P_PPP_SES): {
 274                 struct {
 275                         struct pppoe_hdr hdr;
 276                         __be16 proto;
 277                 } *hdr, _hdr;
 278                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 279                 if (!hdr)
 280                         goto out_bad;
 281                 proto = hdr->proto;
 282                 nhoff += PPPOE_SES_HLEN;
 283                 switch (proto) {
 284                 case htons(PPP_IP):
 285                         goto ip;
 286                 case htons(PPP_IPV6):
 287                         goto ipv6;
 288                 default:
 289                         goto out_bad;
 290                 }
 291         }
 292         case htons(ETH_P_TIPC): {
 293                 struct {
 294                         __be32 pre[3];
 295                         __be32 srcnode;
 296                 } *hdr, _hdr;
 297                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 298                 if (!hdr)
 299                         goto out_bad;
 300
 301                 if (skb_flow_dissector_uses_key(flow_dissector,
 302                                                 FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
 303                         key_addrs = skb_flow_dissector_target(flow_dissector,
 304                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 305                                                               target_container);
 306                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
 307                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
 308                 }
 309                 goto out_good;
 310         }
 311
 312         case htons(ETH_P_MPLS_UC):
 313         case htons(ETH_P_MPLS_MC): {
 314                 struct mpls_label *hdr, _hdr[2];
 315 mpls:
 316                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 317                                            hlen, &_hdr);
 318                 if (!hdr)
 319                         goto out_bad;
 320
 321                 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
 322                      MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
 323                         if (skb_flow_dissector_uses_key(flow_dissector,
 324                                                         FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 325                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 326                                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 327                                                                       target_container);
 328                                 key_keyid->keyid = hdr[1].entry &
 329                                         htonl(MPLS_LS_LABEL_MASK);
 330                         }
 331
 332                         goto out_good;
 333                 }
 334
 335                 goto out_good;
 336         }
 337
 338         case htons(ETH_P_FCOE):
 339                 key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
 340                 /* fall through */
 341         default:
 342                 goto out_bad;
 343         }
 344
 345 ip_proto_again:
 346         switch (ip_proto) {
 347         case IPPROTO_GRE: {
 348                 struct gre_hdr {
 349                         __be16 flags;
 350                         __be16 proto;
 351                 } *hdr, _hdr;
 352
 353                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 354                 if (!hdr)
 355                         goto out_bad;
 356                 /*
 357                  * Only look inside GRE if version zero and no
 358                  * routing
 359                  */
 360                 if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
 361                         break;
 362
 363                 proto = hdr->proto;
 364                 nhoff += 4;
 365                 if (hdr->flags & GRE_CSUM)
 366                         nhoff += 4;
 367                 if (hdr->flags & GRE_KEY) {
 368                         const __be32 *keyid;
 369                         __be32 _keyid;
 370
 371                         keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
 372                                                      data, hlen, &_keyid);
 373
 374                         if (!keyid)
 375                                 goto out_bad;
 376
 377                         if (skb_flow_dissector_uses_key(flow_dissector,
 378                                                         FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 379                                 key_keyid = skb_flow_dissector_target(flow_dissector,
 380                                                                       FLOW_DISSECTOR_KEY_GRE_KEYID,
 381                                                                       target_container);
 382                                 key_keyid->keyid = *keyid;
 383                         }
 384                         nhoff += 4;
 385                 }
 386                 if (hdr->flags & GRE_SEQ)
 387                         nhoff += 4;
 388                 if (proto == htons(ETH_P_TEB)) {
 389                         const struct ethhdr *eth;
 390                         struct ethhdr _eth;
 391
 392                         eth = __skb_header_pointer(skb, nhoff,
 393                                                    sizeof(_eth),
 394                                                    data, hlen, &_eth);
 395                         if (!eth)
 396                                 goto out_bad;
 397                         proto = eth->h_proto;
 398                         nhoff += sizeof(*eth);
 399                 }
 400
 401                 key_control->encapsulation = 1;
 402                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 403                         goto out_good;
 404
 405                 goto again;
 406         }
 407         case NEXTHDR_HOP:
 408         case NEXTHDR_ROUTING:
 409         case NEXTHDR_DEST: {
 410                 u8 _opthdr[2], *opthdr;
 411
 412                 if (proto != htons(ETH_P_IPV6))
 413                         break;
 414
 415                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 416                                               data, hlen, &_opthdr);
 417                 if (!opthdr)
 418                         goto out_bad;
 419
 420                 ip_proto = opthdr[0];
 421                 nhoff += (opthdr[1] + 1) << 3;
 422
 423                 goto ip_proto_again;
 424         }
 425         case NEXTHDR_FRAGMENT: {
 426                 struct frag_hdr _fh, *fh;
 427
 428                 if (proto != htons(ETH_P_IPV6))
 429                         break;
 430
 431                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 432                                           data, hlen, &_fh);
 433
 434                 if (!fh)
 435                         goto out_bad;
 436
 437                 key_control->is_fragment = 1;
 438
 439                 nhoff += sizeof(_fh);
 440
 441                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 442                         key_control->first_frag = 1;
 443                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 444                                 ip_proto = fh->nexthdr;
 445                                 goto ip_proto_again;
 446                         }
 447                 }
 448                 goto out_good;
 449         }
 450         case IPPROTO_IPIP:
 451                 proto = htons(ETH_P_IP);
 452
 453                 key_control->encapsulation = 1;
 454                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 455                         goto out_good;
 456
 457                 goto ip;
 458         case IPPROTO_IPV6:
 459                 proto = htons(ETH_P_IPV6);
 460
 461                 key_control->encapsulation = 1;
 462                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 463                         goto out_good;
 464
 465                 goto ipv6;
 466         case IPPROTO_MPLS:
 467                 proto = htons(ETH_P_MPLS_UC);
 468                 goto mpls;
 469         default:
 470                 break;
 471         }
 472
 473         if (skb_flow_dissector_uses_key(flow_dissector,
 474                                         FLOW_DISSECTOR_KEY_PORTS)) {
 475                 key_ports = skb_flow_dissector_target(flow_dissector,
 476                                                       FLOW_DISSECTOR_KEY_PORTS,
 477                                                       target_container);
 478                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 479                                                         data, hlen);
 480         }
 481
 482 out_good:
 483         ret = true;
 484
 485 out_bad:
 486         key_basic->n_proto = proto;
 487         key_basic->ip_proto = ip_proto;
 488         key_control->thoff = (u16)nhoff;
 489
 490         return ret;
 491 }
 492 EXPORT_SYMBOL(__skb_flow_dissect);
 493
 494 static u32 hashrnd __read_mostly;
 495 static __always_inline void __flow_hash_secret_init(void)
 496 {
 497         net_get_random_once(&hashrnd, sizeof(hashrnd));
 498 }
 499
 500 static __always_inline u32 __flow_hash_words(u32 *words, u32 length, u32 keyval)
 501 {
 502         return jhash2(words, length, keyval);
 503 }
 504
 505 static inline void *flow_keys_hash_start(struct flow_keys *flow)
 506 {
 507         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 508         return (void *)flow + FLOW_KEYS_HASH_OFFSET;
 509 }
 510
 511 static inline size_t flow_keys_hash_length(struct flow_keys *flow)
 512 {
 513         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 514         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 515         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
 516                      sizeof(*flow) - sizeof(flow->addrs));
 517
 518         switch (flow->control.addr_type) {
 519         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 520                 diff -= sizeof(flow->addrs.v4addrs);
 521                 break;
 522         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 523                 diff -= sizeof(flow->addrs.v6addrs);
 524                 break;
 525         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 526                 diff -= sizeof(flow->addrs.tipcaddrs);
 527                 break;
 528         }
 529         return (sizeof(*flow) - diff) / sizeof(u32);
 530 }
 531
 532 __be32 flow_get_u32_src(const struct flow_keys *flow)
 533 {
 534         switch (flow->control.addr_type) {
 535         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 536                 return flow->addrs.v4addrs.src;
 537         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 538                 return (__force __be32)ipv6_addr_hash(
 539                         &flow->addrs.v6addrs.src);
 540         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 541                 return flow->addrs.tipcaddrs.srcnode;
 542         default:
 543                 return 0;
 544         }
 545 }
 546 EXPORT_SYMBOL(flow_get_u32_src);
 547
 548 __be32 flow_get_u32_dst(const struct flow_keys *flow)
 549 {
 550         switch (flow->control.addr_type) {
 551         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 552                 return flow->addrs.v4addrs.dst;
 553         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 554                 return (__force __be32)ipv6_addr_hash(
 555                         &flow->addrs.v6addrs.dst);
 556         default:
 557                 return 0;
 558         }
 559 }
 560 EXPORT_SYMBOL(flow_get_u32_dst);
 561
 562 static inline void __flow_hash_consistentify(struct flow_keys *keys)
 563 {
 564         int addr_diff, i;
 565
 566         switch (keys->control.addr_type) {
 567         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 568                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
 569                             (__force u32)keys->addrs.v4addrs.src;
 570                 if ((addr_diff < 0) ||
 571                     (addr_diff == 0 &&
 572                      ((__force u16)keys->ports.dst <
 573                       (__force u16)keys->ports.src))) {
 574                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
 575                         swap(keys->ports.src, keys->ports.dst);
 576                 }
 577                 break;
 578         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 579                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
 580                                    &keys->addrs.v6addrs.src,
 581                                    sizeof(keys->addrs.v6addrs.dst));
 582                 if ((addr_diff < 0) ||
 583                     (addr_diff == 0 &&
 584                      ((__force u16)keys->ports.dst <
 585                       (__force u16)keys->ports.src))) {
 586                         for (i = 0; i < 4; i++)
 587                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
 588                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
 589                         swap(keys->ports.src, keys->ports.dst);
 590                 }
 591                 break;
 592         }
 593 }
 594
 595 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
 596 {
 597         u32 hash;
 598
 599         __flow_hash_consistentify(keys);
 600
 601         hash = __flow_hash_words((u32 *)flow_keys_hash_start(keys),
 602                                  flow_keys_hash_length(keys), keyval);
 603         if (!hash)
 604                 hash = 1;
 605
 606         return hash;
 607 }
 608
 609 u32 flow_hash_from_keys(struct flow_keys *keys)
 610 {
 611         __flow_hash_secret_init();
 612         return __flow_hash_from_keys(keys, hashrnd);
 613 }
 614 EXPORT_SYMBOL(flow_hash_from_keys);
 615
 616 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
 617                                   struct flow_keys *keys, u32 keyval)
 618 {
 619         if (!skb_flow_dissect_flow_keys(skb, keys,
 620                                         FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL))
 621                 return 0;
 622
 623         return __flow_hash_from_keys(keys, keyval);
 624 }
 625
 626 struct _flow_keys_digest_data {
 627         __be16  n_proto;
 628         u8      ip_proto;
 629         u8      padding;
 630         __be32  ports;
 631         __be32  src;
 632         __be32  dst;
 633 };
 634
 635 void make_flow_keys_digest(struct flow_keys_digest *digest,
 636                            const struct flow_keys *flow)
 637 {
 638         struct _flow_keys_digest_data *data =
 639             (struct _flow_keys_digest_data *)digest;
 640
 641         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
 642
 643         memset(digest, 0, sizeof(*digest));
 644
 645         data->n_proto = flow->basic.n_proto;
 646         data->ip_proto = flow->basic.ip_proto;
 647         data->ports = flow->ports.ports;
 648         data->src = flow->addrs.v4addrs.src;
 649         data->dst = flow->addrs.v4addrs.dst;
 650 }
 651 EXPORT_SYMBOL(make_flow_keys_digest);
 652
 653 /**
 654  * __skb_get_hash: calculate a flow hash
 655  * @skb: sk_buff to calculate flow hash from
 656  *
 657  * This function calculates a flow hash based on src/dst addresses
 658  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 659  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
 660  * if hash is a canonical 4-tuple hash over transport ports.
 661  */
 662 void __skb_get_hash(struct sk_buff *skb)
 663 {
 664         struct flow_keys keys;
 665         u32 hash;
 666
 667         __flow_hash_secret_init();
 668
 669         hash = ___skb_get_hash(skb, &keys, hashrnd);
 670         if (!hash)
 671                 return;
 672
 673         __skb_set_sw_hash(skb, hash,
 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, 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, 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 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
 797         {
 798                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 799                 .offset = offsetof(struct flow_keys, control),
 800         },
 801         {
 802                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 803                 .offset = offsetof(struct flow_keys, basic),
 804         },
 805         {
 806                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 807                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
 808         },
 809         {
 810                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 811                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
 812         },
 813         {
 814                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
 815                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 816         },
 817         {
 818                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
 819                 .offset = offsetof(struct flow_keys, ports),
 820         },
 821         {
 822                 .key_id = FLOW_DISSECTOR_KEY_VLANID,
 823                 .offset = offsetof(struct flow_keys, tags),
 824         },
 825         {
 826                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
 827                 .offset = offsetof(struct flow_keys, tags),
 828         },
 829         {
 830                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
 831                 .offset = offsetof(struct flow_keys, keyid),
 832         },
 833 };
 834
 835 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
 836         {
 837                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
 838                 .offset = offsetof(struct flow_keys, control),
 839         },
 840         {
 841                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
 842                 .offset = offsetof(struct flow_keys, basic),
 843         },
 844 };
 845
 846 struct flow_dissector flow_keys_dissector __read_mostly;
 847 EXPORT_SYMBOL(flow_keys_dissector);
 848
 849 struct flow_dissector flow_keys_buf_dissector __read_mostly;
 850
 851 static int __init init_default_flow_dissectors(void)
 852 {
 853         skb_flow_dissector_init(&flow_keys_dissector,
 854                                 flow_keys_dissector_keys,
 855                                 ARRAY_SIZE(flow_keys_dissector_keys));
 856         skb_flow_dissector_init(&flow_keys_buf_dissector,
 857                                 flow_keys_buf_dissector_keys,
 858                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
 859         return 0;
 860 }
 861
 862 late_initcall_sync(init_default_flow_dissectors);