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/dsa.h>
   8 #include <net/dst_metadata.h>
   9 #include <net/ip.h>
  10 #include <net/ipv6.h>
  11 #include <net/gre.h>
  12 #include <net/pptp.h>
  13 #include <net/tipc.h>
  14 #include <linux/igmp.h>
  15 #include <linux/icmp.h>
  16 #include <linux/sctp.h>
  17 #include <linux/dccp.h>
  18 #include <linux/if_tunnel.h>
  19 #include <linux/if_pppox.h>
  20 #include <linux/ppp_defs.h>
  21 #include <linux/stddef.h>
  22 #include <linux/if_ether.h>
  23 #include <linux/mpls.h>
  24 #include <linux/tcp.h>
  25 #include <net/flow_dissector.h>
  26 #include <scsi/fc/fc_fcoe.h>
  27 #include <uapi/linux/batadv_packet.h>
  28
  29 static void dissector_set_key(struct flow_dissector *flow_dissector,
  30                               enum flow_dissector_key_id key_id)
  31 {
  32         flow_dissector->used_keys |= (1 << key_id);
  33 }
  34
  35 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  36                              const struct flow_dissector_key *key,
  37                              unsigned int key_count)
  38 {
  39         unsigned int i;
  40
  41         memset(flow_dissector, 0, sizeof(*flow_dissector));
  42
  43         for (i = 0; i < key_count; i++, key++) {
  44                 /* User should make sure that every key target offset is withing
  45                  * boundaries of unsigned short.
  46                  */
  47                 BUG_ON(key->offset > USHRT_MAX);
  48                 BUG_ON(dissector_uses_key(flow_dissector,
  49                                           key->key_id));
  50
  51                 dissector_set_key(flow_dissector, key->key_id);
  52                 flow_dissector->offset[key->key_id] = key->offset;
  53         }
  54
  55         /* Ensure that the dissector always includes control and basic key.
  56          * That way we are able to avoid handling lack of these in fast path.
  57          */
  58         BUG_ON(!dissector_uses_key(flow_dissector,
  59                                    FLOW_DISSECTOR_KEY_CONTROL));
  60         BUG_ON(!dissector_uses_key(flow_dissector,
  61                                    FLOW_DISSECTOR_KEY_BASIC));
  62 }
  63 EXPORT_SYMBOL(skb_flow_dissector_init);
  64
  65 /**
  66  * skb_flow_get_be16 - extract be16 entity
  67  * @skb: sk_buff to extract from
  68  * @poff: offset to extract at
  69  * @data: raw buffer pointer to the packet
  70  * @hlen: packet header length
  71  *
  72  * The function will try to retrieve a be32 entity at
  73  * offset poff
  74  */
  75 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
  76                                 void *data, int hlen)
  77 {
  78         __be16 *u, _u;
  79
  80         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
  81         if (u)
  82                 return *u;
  83
  84         return 0;
  85 }
  86
  87 /**
  88  * __skb_flow_get_ports - extract the upper layer ports and return them
  89  * @skb: sk_buff to extract the ports from
  90  * @thoff: transport header offset
  91  * @ip_proto: protocol for which to get port offset
  92  * @data: raw buffer pointer to the packet, if NULL use skb->data
  93  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
  94  *
  95  * The function will try to retrieve the ports at offset thoff + poff where poff
  96  * is the protocol port offset returned from proto_ports_offset
  97  */
  98 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
  99                             void *data, int hlen)
 100 {
 101         int poff = proto_ports_offset(ip_proto);
 102
 103         if (!data) {
 104                 data = skb->data;
 105                 hlen = skb_headlen(skb);
 106         }
 107
 108         if (poff >= 0) {
 109                 __be32 *ports, _ports;
 110
 111                 ports = __skb_header_pointer(skb, thoff + poff,
 112                                              sizeof(_ports), data, hlen, &_ports);
 113                 if (ports)
 114                         return *ports;
 115         }
 116
 117         return 0;
 118 }
 119 EXPORT_SYMBOL(__skb_flow_get_ports);
 120
 121 static void
 122 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
 123                                    struct flow_dissector *flow_dissector,
 124                                    void *target_container)
 125 {
 126         struct flow_dissector_key_control *ctrl;
 127
 128         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
 129                 return;
 130
 131         ctrl = skb_flow_dissector_target(flow_dissector,
 132                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
 133                                          target_container);
 134         ctrl->addr_type = type;
 135 }
 136
 137 void
 138 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
 139                              struct flow_dissector *flow_dissector,
 140                              void *target_container)
 141 {
 142         struct ip_tunnel_info *info;
 143         struct ip_tunnel_key *key;
 144
 145         /* A quick check to see if there might be something to do. */
 146         if (!dissector_uses_key(flow_dissector,
 147                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
 148             !dissector_uses_key(flow_dissector,
 149                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
 150             !dissector_uses_key(flow_dissector,
 151                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
 152             !dissector_uses_key(flow_dissector,
 153                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
 154             !dissector_uses_key(flow_dissector,
 155                                 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
 156             !dissector_uses_key(flow_dissector,
 157                                 FLOW_DISSECTOR_KEY_ENC_IP) &&
 158             !dissector_uses_key(flow_dissector,
 159                                 FLOW_DISSECTOR_KEY_ENC_OPTS))
 160                 return;
 161
 162         info = skb_tunnel_info(skb);
 163         if (!info)
 164                 return;
 165
 166         key = &info->key;
 167
 168         switch (ip_tunnel_info_af(info)) {
 169         case AF_INET:
 170                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 171                                                    flow_dissector,
 172                                                    target_container);
 173                 if (dissector_uses_key(flow_dissector,
 174                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 175                         struct flow_dissector_key_ipv4_addrs *ipv4;
 176
 177                         ipv4 = skb_flow_dissector_target(flow_dissector,
 178                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 179                                                          target_container);
 180                         ipv4->src = key->u.ipv4.src;
 181                         ipv4->dst = key->u.ipv4.dst;
 182                 }
 183                 break;
 184         case AF_INET6:
 185                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 186                                                    flow_dissector,
 187                                                    target_container);
 188                 if (dissector_uses_key(flow_dissector,
 189                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 190                         struct flow_dissector_key_ipv6_addrs *ipv6;
 191
 192                         ipv6 = skb_flow_dissector_target(flow_dissector,
 193                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 194                                                          target_container);
 195                         ipv6->src = key->u.ipv6.src;
 196                         ipv6->dst = key->u.ipv6.dst;
 197                 }
 198                 break;
 199         }
 200
 201         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 202                 struct flow_dissector_key_keyid *keyid;
 203
 204                 keyid = skb_flow_dissector_target(flow_dissector,
 205                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
 206                                                   target_container);
 207                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
 208         }
 209
 210         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 211                 struct flow_dissector_key_ports *tp;
 212
 213                 tp = skb_flow_dissector_target(flow_dissector,
 214                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
 215                                                target_container);
 216                 tp->src = key->tp_src;
 217                 tp->dst = key->tp_dst;
 218         }
 219
 220         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
 221                 struct flow_dissector_key_ip *ip;
 222
 223                 ip = skb_flow_dissector_target(flow_dissector,
 224                                                FLOW_DISSECTOR_KEY_ENC_IP,
 225                                                target_container);
 226                 ip->tos = key->tos;
 227                 ip->ttl = key->ttl;
 228         }
 229
 230         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
 231                 struct flow_dissector_key_enc_opts *enc_opt;
 232
 233                 enc_opt = skb_flow_dissector_target(flow_dissector,
 234                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
 235                                                     target_container);
 236
 237                 if (info->options_len) {
 238                         enc_opt->len = info->options_len;
 239                         ip_tunnel_info_opts_get(enc_opt->data, info);
 240                         enc_opt->dst_opt_type = info->key.tun_flags &
 241                                                 TUNNEL_OPTIONS_PRESENT;
 242                 }
 243         }
 244 }
 245 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 246
 247 static enum flow_dissect_ret
 248 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 249                         struct flow_dissector *flow_dissector,
 250                         void *target_container, void *data, int nhoff, int hlen)
 251 {
 252         struct flow_dissector_key_keyid *key_keyid;
 253         struct mpls_label *hdr, _hdr[2];
 254         u32 entry, label;
 255
 256         if (!dissector_uses_key(flow_dissector,
 257                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 258             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 259                 return FLOW_DISSECT_RET_OUT_GOOD;
 260
 261         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 262                                    hlen, &_hdr);
 263         if (!hdr)
 264                 return FLOW_DISSECT_RET_OUT_BAD;
 265
 266         entry = ntohl(hdr[0].entry);
 267         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 268
 269         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 270                 struct flow_dissector_key_mpls *key_mpls;
 271
 272                 key_mpls = skb_flow_dissector_target(flow_dissector,
 273                                                      FLOW_DISSECTOR_KEY_MPLS,
 274                                                      target_container);
 275                 key_mpls->mpls_label = label;
 276                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
 277                                         >> MPLS_LS_TTL_SHIFT;
 278                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
 279                                         >> MPLS_LS_TC_SHIFT;
 280                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
 281                                         >> MPLS_LS_S_SHIFT;
 282         }
 283
 284         if (label == MPLS_LABEL_ENTROPY) {
 285                 key_keyid = skb_flow_dissector_target(flow_dissector,
 286                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 287                                                       target_container);
 288                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
 289         }
 290         return FLOW_DISSECT_RET_OUT_GOOD;
 291 }
 292
 293 static enum flow_dissect_ret
 294 __skb_flow_dissect_arp(const struct sk_buff *skb,
 295                        struct flow_dissector *flow_dissector,
 296                        void *target_container, void *data, int nhoff, int hlen)
 297 {
 298         struct flow_dissector_key_arp *key_arp;
 299         struct {
 300                 unsigned char ar_sha[ETH_ALEN];
 301                 unsigned char ar_sip[4];
 302                 unsigned char ar_tha[ETH_ALEN];
 303                 unsigned char ar_tip[4];
 304         } *arp_eth, _arp_eth;
 305         const struct arphdr *arp;
 306         struct arphdr _arp;
 307
 308         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 309                 return FLOW_DISSECT_RET_OUT_GOOD;
 310
 311         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 312                                    hlen, &_arp);
 313         if (!arp)
 314                 return FLOW_DISSECT_RET_OUT_BAD;
 315
 316         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 317             arp->ar_pro != htons(ETH_P_IP) ||
 318             arp->ar_hln != ETH_ALEN ||
 319             arp->ar_pln != 4 ||
 320             (arp->ar_op != htons(ARPOP_REPLY) &&
 321              arp->ar_op != htons(ARPOP_REQUEST)))
 322                 return FLOW_DISSECT_RET_OUT_BAD;
 323
 324         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 325                                        sizeof(_arp_eth), data,
 326                                        hlen, &_arp_eth);
 327         if (!arp_eth)
 328                 return FLOW_DISSECT_RET_OUT_BAD;
 329
 330         key_arp = skb_flow_dissector_target(flow_dissector,
 331                                             FLOW_DISSECTOR_KEY_ARP,
 332                                             target_container);
 333
 334         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 335         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 336
 337         /* Only store the lower byte of the opcode;
 338          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 339          */
 340         key_arp->op = ntohs(arp->ar_op) & 0xff;
 341
 342         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 343         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 344
 345         return FLOW_DISSECT_RET_OUT_GOOD;
 346 }
 347
 348 static enum flow_dissect_ret
 349 __skb_flow_dissect_gre(const struct sk_buff *skb,
 350                        struct flow_dissector_key_control *key_control,
 351                        struct flow_dissector *flow_dissector,
 352                        void *target_container, void *data,
 353                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 354                        unsigned int flags)
 355 {
 356         struct flow_dissector_key_keyid *key_keyid;
 357         struct gre_base_hdr *hdr, _hdr;
 358         int offset = 0;
 359         u16 gre_ver;
 360
 361         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 362                                    data, *p_hlen, &_hdr);
 363         if (!hdr)
 364                 return FLOW_DISSECT_RET_OUT_BAD;
 365
 366         /* Only look inside GRE without routing */
 367         if (hdr->flags & GRE_ROUTING)
 368                 return FLOW_DISSECT_RET_OUT_GOOD;
 369
 370         /* Only look inside GRE for version 0 and 1 */
 371         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 372         if (gre_ver > 1)
 373                 return FLOW_DISSECT_RET_OUT_GOOD;
 374
 375         *p_proto = hdr->protocol;
 376         if (gre_ver) {
 377                 /* Version1 must be PPTP, and check the flags */
 378                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 379                         return FLOW_DISSECT_RET_OUT_GOOD;
 380         }
 381
 382         offset += sizeof(struct gre_base_hdr);
 383
 384         if (hdr->flags & GRE_CSUM)
 385                 offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
 386                           sizeof(((struct gre_full_hdr *) 0)->reserved1);
 387
 388         if (hdr->flags & GRE_KEY) {
 389                 const __be32 *keyid;
 390                 __be32 _keyid;
 391
 392                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 393                                              sizeof(_keyid),
 394                                              data, *p_hlen, &_keyid);
 395                 if (!keyid)
 396                         return FLOW_DISSECT_RET_OUT_BAD;
 397
 398                 if (dissector_uses_key(flow_dissector,
 399                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 400                         key_keyid = skb_flow_dissector_target(flow_dissector,
 401                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 402                                                               target_container);
 403                         if (gre_ver == 0)
 404                                 key_keyid->keyid = *keyid;
 405                         else
 406                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 407                 }
 408                 offset += sizeof(((struct gre_full_hdr *) 0)->key);
 409         }
 410
 411         if (hdr->flags & GRE_SEQ)
 412                 offset += sizeof(((struct pptp_gre_header *) 0)->seq);
 413
 414         if (gre_ver == 0) {
 415                 if (*p_proto == htons(ETH_P_TEB)) {
 416                         const struct ethhdr *eth;
 417                         struct ethhdr _eth;
 418
 419                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 420                                                    sizeof(_eth),
 421                                                    data, *p_hlen, &_eth);
 422                         if (!eth)
 423                                 return FLOW_DISSECT_RET_OUT_BAD;
 424                         *p_proto = eth->h_proto;
 425                         offset += sizeof(*eth);
 426
 427                         /* Cap headers that we access via pointers at the
 428                          * end of the Ethernet header as our maximum alignment
 429                          * at that point is only 2 bytes.
 430                          */
 431                         if (NET_IP_ALIGN)
 432                                 *p_hlen = *p_nhoff + offset;
 433                 }
 434         } else { /* version 1, must be PPTP */
 435                 u8 _ppp_hdr[PPP_HDRLEN];
 436                 u8 *ppp_hdr;
 437
 438                 if (hdr->flags & GRE_ACK)
 439                         offset += sizeof(((struct pptp_gre_header *) 0)->ack);
 440
 441                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 442                                                sizeof(_ppp_hdr),
 443                                                data, *p_hlen, _ppp_hdr);
 444                 if (!ppp_hdr)
 445                         return FLOW_DISSECT_RET_OUT_BAD;
 446
 447                 switch (PPP_PROTOCOL(ppp_hdr)) {
 448                 case PPP_IP:
 449                         *p_proto = htons(ETH_P_IP);
 450                         break;
 451                 case PPP_IPV6:
 452                         *p_proto = htons(ETH_P_IPV6);
 453                         break;
 454                 default:
 455                         /* Could probably catch some more like MPLS */
 456                         break;
 457                 }
 458
 459                 offset += PPP_HDRLEN;
 460         }
 461
 462         *p_nhoff += offset;
 463         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 464         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 465                 return FLOW_DISSECT_RET_OUT_GOOD;
 466
 467         return FLOW_DISSECT_RET_PROTO_AGAIN;
 468 }
 469
 470 /**
 471  * __skb_flow_dissect_batadv() - dissect batman-adv header
 472  * @skb: sk_buff to with the batman-adv header
 473  * @key_control: flow dissectors control key
 474  * @data: raw buffer pointer to the packet, if NULL use skb->data
 475  * @p_proto: pointer used to update the protocol to process next
 476  * @p_nhoff: pointer used to update inner network header offset
 477  * @hlen: packet header length
 478  * @flags: any combination of FLOW_DISSECTOR_F_*
 479  *
 480  * ETH_P_BATMAN packets are tried to be dissected. Only
 481  * &struct batadv_unicast packets are actually processed because they contain an
 482  * inner ethernet header and are usually followed by actual network header. This
 483  * allows the flow dissector to continue processing the packet.
 484  *
 485  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 486  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 487  *  otherwise FLOW_DISSECT_RET_OUT_BAD
 488  */
 489 static enum flow_dissect_ret
 490 __skb_flow_dissect_batadv(const struct sk_buff *skb,
 491                           struct flow_dissector_key_control *key_control,
 492                           void *data, __be16 *p_proto, int *p_nhoff, int hlen,
 493                           unsigned int flags)
 494 {
 495         struct {
 496                 struct batadv_unicast_packet batadv_unicast;
 497                 struct ethhdr eth;
 498         } *hdr, _hdr;
 499
 500         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 501                                    &_hdr);
 502         if (!hdr)
 503                 return FLOW_DISSECT_RET_OUT_BAD;
 504
 505         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 506                 return FLOW_DISSECT_RET_OUT_BAD;
 507
 508         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 509                 return FLOW_DISSECT_RET_OUT_BAD;
 510
 511         *p_proto = hdr->eth.h_proto;
 512         *p_nhoff += sizeof(*hdr);
 513
 514         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 515         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 516                 return FLOW_DISSECT_RET_OUT_GOOD;
 517
 518         return FLOW_DISSECT_RET_PROTO_AGAIN;
 519 }
 520
 521 static void
 522 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 523                        struct flow_dissector *flow_dissector,
 524                        void *target_container, void *data, int thoff, int hlen)
 525 {
 526         struct flow_dissector_key_tcp *key_tcp;
 527         struct tcphdr *th, _th;
 528
 529         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 530                 return;
 531
 532         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 533         if (!th)
 534                 return;
 535
 536         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 537                 return;
 538
 539         key_tcp = skb_flow_dissector_target(flow_dissector,
 540                                             FLOW_DISSECTOR_KEY_TCP,
 541                                             target_container);
 542         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 543 }
 544
 545 static void
 546 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 547                         struct flow_dissector *flow_dissector,
 548                         void *target_container, void *data, const struct iphdr *iph)
 549 {
 550         struct flow_dissector_key_ip *key_ip;
 551
 552         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 553                 return;
 554
 555         key_ip = skb_flow_dissector_target(flow_dissector,
 556                                            FLOW_DISSECTOR_KEY_IP,
 557                                            target_container);
 558         key_ip->tos = iph->tos;
 559         key_ip->ttl = iph->ttl;
 560 }
 561
 562 static void
 563 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 564                         struct flow_dissector *flow_dissector,
 565                         void *target_container, void *data, const struct ipv6hdr *iph)
 566 {
 567         struct flow_dissector_key_ip *key_ip;
 568
 569         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 570                 return;
 571
 572         key_ip = skb_flow_dissector_target(flow_dissector,
 573                                            FLOW_DISSECTOR_KEY_IP,
 574                                            target_container);
 575         key_ip->tos = ipv6_get_dsfield(iph);
 576         key_ip->ttl = iph->hop_limit;
 577 }
 578
 579 /* Maximum number of protocol headers that can be parsed in
 580  * __skb_flow_dissect
 581  */
 582 #define MAX_FLOW_DISSECT_HDRS   15
 583
 584 static bool skb_flow_dissect_allowed(int *num_hdrs)
 585 {
 586         ++*num_hdrs;
 587
 588         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 589 }
 590
 591 /**
 592  * __skb_flow_dissect - extract the flow_keys struct and return it
 593  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 594  * @flow_dissector: list of keys to dissect
 595  * @target_container: target structure to put dissected values into
 596  * @data: raw buffer pointer to the packet, if NULL use skb->data
 597  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 598  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 599  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 600  *
 601  * The function will try to retrieve individual keys into target specified
 602  * by flow_dissector from either the skbuff or a raw buffer specified by the
 603  * rest parameters.
 604  *
 605  * Caller must take care of zeroing target container memory.
 606  */
 607 bool __skb_flow_dissect(const struct sk_buff *skb,
 608                         struct flow_dissector *flow_dissector,
 609                         void *target_container,
 610                         void *data, __be16 proto, int nhoff, int hlen,
 611                         unsigned int flags)
 612 {
 613         struct flow_dissector_key_control *key_control;
 614         struct flow_dissector_key_basic *key_basic;
 615         struct flow_dissector_key_addrs *key_addrs;
 616         struct flow_dissector_key_ports *key_ports;
 617         struct flow_dissector_key_icmp *key_icmp;
 618         struct flow_dissector_key_tags *key_tags;
 619         struct flow_dissector_key_vlan *key_vlan;
 620         enum flow_dissect_ret fdret;
 621         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
 622         int num_hdrs = 0;
 623         u8 ip_proto = 0;
 624         bool ret;
 625
 626         if (!data) {
 627                 data = skb->data;
 628                 proto = skb_vlan_tag_present(skb) ?
 629                          skb->vlan_proto : skb->protocol;
 630                 nhoff = skb_network_offset(skb);
 631                 hlen = skb_headlen(skb);
 632 #if IS_ENABLED(CONFIG_NET_DSA)
 633                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
 634                              proto == htons(ETH_P_XDSA))) {
 635                         const struct dsa_device_ops *ops;
 636                         int offset = 0;
 637
 638                         ops = skb->dev->dsa_ptr->tag_ops;
 639                         if (ops->flow_dissect &&
 640                             !ops->flow_dissect(skb, &proto, &offset)) {
 641                                 hlen -= offset;
 642                                 nhoff += offset;
 643                         }
 644                 }
 645 #endif
 646         }
 647
 648         /* It is ensured by skb_flow_dissector_init() that control key will
 649          * be always present.
 650          */
 651         key_control = skb_flow_dissector_target(flow_dissector,
 652                                                 FLOW_DISSECTOR_KEY_CONTROL,
 653                                                 target_container);
 654
 655         /* It is ensured by skb_flow_dissector_init() that basic key will
 656          * be always present.
 657          */
 658         key_basic = skb_flow_dissector_target(flow_dissector,
 659                                               FLOW_DISSECTOR_KEY_BASIC,
 660                                               target_container);
 661
 662         if (dissector_uses_key(flow_dissector,
 663                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 664                 struct ethhdr *eth = eth_hdr(skb);
 665                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 666
 667                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 668                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 669                                                           target_container);
 670                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 671         }
 672
 673 proto_again:
 674         fdret = FLOW_DISSECT_RET_CONTINUE;
 675
 676         switch (proto) {
 677         case htons(ETH_P_IP): {
 678                 const struct iphdr *iph;
 679                 struct iphdr _iph;
 680
 681                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 682                 if (!iph || iph->ihl < 5) {
 683                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 684                         break;
 685                 }
 686
 687                 nhoff += iph->ihl * 4;
 688
 689                 ip_proto = iph->protocol;
 690
 691                 if (dissector_uses_key(flow_dissector,
 692                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 693                         key_addrs = skb_flow_dissector_target(flow_dissector,
 694                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 695                                                               target_container);
 696
 697                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 698                                sizeof(key_addrs->v4addrs));
 699                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 700                 }
 701
 702                 if (ip_is_fragment(iph)) {
 703                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 704
 705                         if (iph->frag_off & htons(IP_OFFSET)) {
 706                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 707                                 break;
 708                         } else {
 709                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 710                                 if (!(flags &
 711                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
 712                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 713                                         break;
 714                                 }
 715                         }
 716                 }
 717
 718                 __skb_flow_dissect_ipv4(skb, flow_dissector,
 719                                         target_container, data, iph);
 720
 721                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
 722                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 723                         break;
 724                 }
 725
 726                 break;
 727         }
 728         case htons(ETH_P_IPV6): {
 729                 const struct ipv6hdr *iph;
 730                 struct ipv6hdr _iph;
 731
 732                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 733                 if (!iph) {
 734                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 735                         break;
 736                 }
 737
 738                 ip_proto = iph->nexthdr;
 739                 nhoff += sizeof(struct ipv6hdr);
 740
 741                 if (dissector_uses_key(flow_dissector,
 742                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 743                         key_addrs = skb_flow_dissector_target(flow_dissector,
 744                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 745                                                               target_container);
 746
 747                         memcpy(&key_addrs->v6addrs, &iph->saddr,
 748                                sizeof(key_addrs->v6addrs));
 749                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 750                 }
 751
 752                 if ((dissector_uses_key(flow_dissector,
 753                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
 754                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
 755                     ip6_flowlabel(iph)) {
 756                         __be32 flow_label = ip6_flowlabel(iph);
 757
 758                         if (dissector_uses_key(flow_dissector,
 759                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 760                                 key_tags = skb_flow_dissector_target(flow_dissector,
 761                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
 762                                                                      target_container);
 763                                 key_tags->flow_label = ntohl(flow_label);
 764                         }
 765                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
 766                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 767                                 break;
 768                         }
 769                 }
 770
 771                 __skb_flow_dissect_ipv6(skb, flow_dissector,
 772                                         target_container, data, iph);
 773
 774                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
 775                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 776
 777                 break;
 778         }
 779         case htons(ETH_P_8021AD):
 780         case htons(ETH_P_8021Q): {
 781                 const struct vlan_hdr *vlan = NULL;
 782                 struct vlan_hdr _vlan;
 783                 __be16 saved_vlan_tpid = proto;
 784
 785                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
 786                     skb && skb_vlan_tag_present(skb)) {
 787                         proto = skb->protocol;
 788                 } else {
 789                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
 790                                                     data, hlen, &_vlan);
 791                         if (!vlan) {
 792                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 793                                 break;
 794                         }
 795
 796                         proto = vlan->h_vlan_encapsulated_proto;
 797                         nhoff += sizeof(*vlan);
 798                 }
 799
 800                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
 801                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
 802                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
 803                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
 804                 } else {
 805                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 806                         break;
 807                 }
 808
 809                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
 810                         key_vlan = skb_flow_dissector_target(flow_dissector,
 811                                                              dissector_vlan,
 812                                                              target_container);
 813
 814                         if (!vlan) {
 815                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
 816                                 key_vlan->vlan_priority =
 817                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
 818                         } else {
 819                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 820                                         VLAN_VID_MASK;
 821                                 key_vlan->vlan_priority =
 822                                         (ntohs(vlan->h_vlan_TCI) &
 823                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
 824                         }
 825                         key_vlan->vlan_tpid = saved_vlan_tpid;
 826                 }
 827
 828                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 829                 break;
 830         }
 831         case htons(ETH_P_PPP_SES): {
 832                 struct {
 833                         struct pppoe_hdr hdr;
 834                         __be16 proto;
 835                 } *hdr, _hdr;
 836                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 837                 if (!hdr) {
 838                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 839                         break;
 840                 }
 841
 842                 proto = hdr->proto;
 843                 nhoff += PPPOE_SES_HLEN;
 844                 switch (proto) {
 845                 case htons(PPP_IP):
 846                         proto = htons(ETH_P_IP);
 847                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 848                         break;
 849                 case htons(PPP_IPV6):
 850                         proto = htons(ETH_P_IPV6);
 851                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
 852                         break;
 853                 default:
 854                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 855                         break;
 856                 }
 857                 break;
 858         }
 859         case htons(ETH_P_TIPC): {
 860                 struct tipc_basic_hdr *hdr, _hdr;
 861
 862                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
 863                                            data, hlen, &_hdr);
 864                 if (!hdr) {
 865                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 866                         break;
 867                 }
 868
 869                 if (dissector_uses_key(flow_dissector,
 870                                        FLOW_DISSECTOR_KEY_TIPC)) {
 871                         key_addrs = skb_flow_dissector_target(flow_dissector,
 872                                                               FLOW_DISSECTOR_KEY_TIPC,
 873                                                               target_container);
 874                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
 875                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
 876                 }
 877                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 878                 break;
 879         }
 880
 881         case htons(ETH_P_MPLS_UC):
 882         case htons(ETH_P_MPLS_MC):
 883                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
 884                                                 target_container, data,
 885                                                 nhoff, hlen);
 886                 break;
 887         case htons(ETH_P_FCOE):
 888                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
 889                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 890                         break;
 891                 }
 892
 893                 nhoff += FCOE_HEADER_LEN;
 894                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 895                 break;
 896
 897         case htons(ETH_P_ARP):
 898         case htons(ETH_P_RARP):
 899                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
 900                                                target_container, data,
 901                                                nhoff, hlen);
 902                 break;
 903
 904         case htons(ETH_P_BATMAN):
 905                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
 906                                                   &proto, &nhoff, hlen, flags);
 907                 break;
 908
 909         default:
 910                 fdret = FLOW_DISSECT_RET_OUT_BAD;
 911                 break;
 912         }
 913
 914         /* Process result of proto processing */
 915         switch (fdret) {
 916         case FLOW_DISSECT_RET_OUT_GOOD:
 917                 goto out_good;
 918         case FLOW_DISSECT_RET_PROTO_AGAIN:
 919                 if (skb_flow_dissect_allowed(&num_hdrs))
 920                         goto proto_again;
 921                 goto out_good;
 922         case FLOW_DISSECT_RET_CONTINUE:
 923         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
 924                 break;
 925         case FLOW_DISSECT_RET_OUT_BAD:
 926         default:
 927                 goto out_bad;
 928         }
 929
 930 ip_proto_again:
 931         fdret = FLOW_DISSECT_RET_CONTINUE;
 932
 933         switch (ip_proto) {
 934         case IPPROTO_GRE:
 935                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
 936                                                target_container, data,
 937                                                &proto, &nhoff, &hlen, flags);
 938                 break;
 939
 940         case NEXTHDR_HOP:
 941         case NEXTHDR_ROUTING:
 942         case NEXTHDR_DEST: {
 943                 u8 _opthdr[2], *opthdr;
 944
 945                 if (proto != htons(ETH_P_IPV6))
 946                         break;
 947
 948                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
 949                                               data, hlen, &_opthdr);
 950                 if (!opthdr) {
 951                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 952                         break;
 953                 }
 954
 955                 ip_proto = opthdr[0];
 956                 nhoff += (opthdr[1] + 1) << 3;
 957
 958                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 959                 break;
 960         }
 961         case NEXTHDR_FRAGMENT: {
 962                 struct frag_hdr _fh, *fh;
 963
 964                 if (proto != htons(ETH_P_IPV6))
 965                         break;
 966
 967                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
 968                                           data, hlen, &_fh);
 969
 970                 if (!fh) {
 971                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 972                         break;
 973                 }
 974
 975                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 976
 977                 nhoff += sizeof(_fh);
 978                 ip_proto = fh->nexthdr;
 979
 980                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
 981                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
 982                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
 983                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
 984                                 break;
 985                         }
 986                 }
 987
 988                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 989                 break;
 990         }
 991         case IPPROTO_IPIP:
 992                 proto = htons(ETH_P_IP);
 993
 994                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 995                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
 996                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 997                         break;
 998                 }
 999
1000                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1001                 break;
1002
1003         case IPPROTO_IPV6:
1004                 proto = htons(ETH_P_IPV6);
1005
1006                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1007                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1008                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1009                         break;
1010                 }
1011
1012                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1013                 break;
1014
1015
1016         case IPPROTO_MPLS:
1017                 proto = htons(ETH_P_MPLS_UC);
1018                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1019                 break;
1020
1021         case IPPROTO_TCP:
1022                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1023                                        data, nhoff, hlen);
1024                 break;
1025
1026         default:
1027                 break;
1028         }
1029
1030         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1031             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1032                 key_ports = skb_flow_dissector_target(flow_dissector,
1033                                                       FLOW_DISSECTOR_KEY_PORTS,
1034                                                       target_container);
1035                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1036                                                         data, hlen);
1037         }
1038
1039         if (dissector_uses_key(flow_dissector,
1040                                FLOW_DISSECTOR_KEY_ICMP)) {
1041                 key_icmp = skb_flow_dissector_target(flow_dissector,
1042                                                      FLOW_DISSECTOR_KEY_ICMP,
1043                                                      target_container);
1044                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1045         }
1046
1047         /* Process result of IP proto processing */
1048         switch (fdret) {
1049         case FLOW_DISSECT_RET_PROTO_AGAIN:
1050                 if (skb_flow_dissect_allowed(&num_hdrs))
1051                         goto proto_again;
1052                 break;
1053         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1054                 if (skb_flow_dissect_allowed(&num_hdrs))
1055                         goto ip_proto_again;
1056                 break;
1057         case FLOW_DISSECT_RET_OUT_GOOD:
1058         case FLOW_DISSECT_RET_CONTINUE:
1059                 break;
1060         case FLOW_DISSECT_RET_OUT_BAD:
1061         default:
1062                 goto out_bad;
1063         }
1064
1065 out_good:
1066         ret = true;
1067
1068 out:
1069         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1070         key_basic->n_proto = proto;
1071         key_basic->ip_proto = ip_proto;
1072
1073         return ret;
1074
1075 out_bad:
1076         ret = false;
1077         goto out;
1078 }
1079 EXPORT_SYMBOL(__skb_flow_dissect);
1080
1081 static siphash_key_t hashrnd __read_mostly;
1082 static __always_inline void __flow_hash_secret_init(void)
1083 {
1084         net_get_random_once(&hashrnd, sizeof(hashrnd));
1085 }
1086
1087 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1088 {
1089         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1090         return &flow->FLOW_KEYS_HASH_START_FIELD;
1091 }
1092
1093 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1094 {
1095         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1096         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1097                      sizeof(*flow) - sizeof(flow->addrs));
1098
1099         switch (flow->control.addr_type) {
1100         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1101                 diff -= sizeof(flow->addrs.v4addrs);
1102                 break;
1103         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1104                 diff -= sizeof(flow->addrs.v6addrs);
1105                 break;
1106         case FLOW_DISSECTOR_KEY_TIPC:
1107                 diff -= sizeof(flow->addrs.tipckey);
1108                 break;
1109         }
1110         return sizeof(*flow) - diff;
1111 }
1112
1113 __be32 flow_get_u32_src(const struct flow_keys *flow)
1114 {
1115         switch (flow->control.addr_type) {
1116         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1117                 return flow->addrs.v4addrs.src;
1118         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1119                 return (__force __be32)ipv6_addr_hash(
1120                         &flow->addrs.v6addrs.src);
1121         case FLOW_DISSECTOR_KEY_TIPC:
1122                 return flow->addrs.tipckey.key;
1123         default:
1124                 return 0;
1125         }
1126 }
1127 EXPORT_SYMBOL(flow_get_u32_src);
1128
1129 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1130 {
1131         switch (flow->control.addr_type) {
1132         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1133                 return flow->addrs.v4addrs.dst;
1134         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1135                 return (__force __be32)ipv6_addr_hash(
1136                         &flow->addrs.v6addrs.dst);
1137         default:
1138                 return 0;
1139         }
1140 }
1141 EXPORT_SYMBOL(flow_get_u32_dst);
1142
1143 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1144 {
1145         int addr_diff, i;
1146
1147         switch (keys->control.addr_type) {
1148         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1149                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1150                             (__force u32)keys->addrs.v4addrs.src;
1151                 if ((addr_diff < 0) ||
1152                     (addr_diff == 0 &&
1153                      ((__force u16)keys->ports.dst <
1154                       (__force u16)keys->ports.src))) {
1155                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1156                         swap(keys->ports.src, keys->ports.dst);
1157                 }
1158                 break;
1159         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1160                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1161                                    &keys->addrs.v6addrs.src,
1162                                    sizeof(keys->addrs.v6addrs.dst));
1163                 if ((addr_diff < 0) ||
1164                     (addr_diff == 0 &&
1165                      ((__force u16)keys->ports.dst <
1166                       (__force u16)keys->ports.src))) {
1167                         for (i = 0; i < 4; i++)
1168                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1169                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1170                         swap(keys->ports.src, keys->ports.dst);
1171                 }
1172                 break;
1173         }
1174 }
1175
1176 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1177                                         const siphash_key_t *keyval)
1178 {
1179         u32 hash;
1180
1181         __flow_hash_consistentify(keys);
1182
1183         hash = siphash(flow_keys_hash_start(keys),
1184                        flow_keys_hash_length(keys), keyval);
1185         if (!hash)
1186                 hash = 1;
1187
1188         return hash;
1189 }
1190
1191 u32 flow_hash_from_keys(struct flow_keys *keys)
1192 {
1193         __flow_hash_secret_init();
1194         return __flow_hash_from_keys(keys, &hashrnd);
1195 }
1196 EXPORT_SYMBOL(flow_hash_from_keys);
1197
1198 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1199                                   struct flow_keys *keys,
1200                                   const siphash_key_t *keyval)
1201 {
1202         skb_flow_dissect_flow_keys(skb, keys,
1203                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1204
1205         return __flow_hash_from_keys(keys, keyval);
1206 }
1207
1208 struct _flow_keys_digest_data {
1209         __be16  n_proto;
1210         u8      ip_proto;
1211         u8      padding;
1212         __be32  ports;
1213         __be32  src;
1214         __be32  dst;
1215 };
1216
1217 void make_flow_keys_digest(struct flow_keys_digest *digest,
1218                            const struct flow_keys *flow)
1219 {
1220         struct _flow_keys_digest_data *data =
1221             (struct _flow_keys_digest_data *)digest;
1222
1223         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1224
1225         memset(digest, 0, sizeof(*digest));
1226
1227         data->n_proto = flow->basic.n_proto;
1228         data->ip_proto = flow->basic.ip_proto;
1229         data->ports = flow->ports.ports;
1230         data->src = flow->addrs.v4addrs.src;
1231         data->dst = flow->addrs.v4addrs.dst;
1232 }
1233 EXPORT_SYMBOL(make_flow_keys_digest);
1234
1235 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1236
1237 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1238 {
1239         struct flow_keys keys;
1240
1241         __flow_hash_secret_init();
1242
1243         memset(&keys, 0, sizeof(keys));
1244         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1245                            NULL, 0, 0, 0,
1246                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1247
1248         return __flow_hash_from_keys(&keys, &hashrnd);
1249 }
1250 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1251
1252 /**
1253  * __skb_get_hash: calculate a flow hash
1254  * @skb: sk_buff to calculate flow hash from
1255  *
1256  * This function calculates a flow hash based on src/dst addresses
1257  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1258  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1259  * if hash is a canonical 4-tuple hash over transport ports.
1260  */
1261 void __skb_get_hash(struct sk_buff *skb)
1262 {
1263         struct flow_keys keys;
1264         u32 hash;
1265
1266         __flow_hash_secret_init();
1267
1268         hash = ___skb_get_hash(skb, &keys, &hashrnd);
1269
1270         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1271 }
1272 EXPORT_SYMBOL(__skb_get_hash);
1273
1274 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1275                            const siphash_key_t *perturb)
1276 {
1277         struct flow_keys keys;
1278
1279         return ___skb_get_hash(skb, &keys, perturb);
1280 }
1281 EXPORT_SYMBOL(skb_get_hash_perturb);
1282
1283 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1284                    const struct flow_keys_basic *keys, int hlen)
1285 {
1286         u32 poff = keys->control.thoff;
1287
1288         /* skip L4 headers for fragments after the first */
1289         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1290             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1291                 return poff;
1292
1293         switch (keys->basic.ip_proto) {
1294         case IPPROTO_TCP: {
1295                 /* access doff as u8 to avoid unaligned access */
1296                 const u8 *doff;
1297                 u8 _doff;
1298
1299                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1300                                             data, hlen, &_doff);
1301                 if (!doff)
1302                         return poff;
1303
1304                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1305                 break;
1306         }
1307         case IPPROTO_UDP:
1308         case IPPROTO_UDPLITE:
1309                 poff += sizeof(struct udphdr);
1310                 break;
1311         /* For the rest, we do not really care about header
1312          * extensions at this point for now.
1313          */
1314         case IPPROTO_ICMP:
1315                 poff += sizeof(struct icmphdr);
1316                 break;
1317         case IPPROTO_ICMPV6:
1318                 poff += sizeof(struct icmp6hdr);
1319                 break;
1320         case IPPROTO_IGMP:
1321                 poff += sizeof(struct igmphdr);
1322                 break;
1323         case IPPROTO_DCCP:
1324                 poff += sizeof(struct dccp_hdr);
1325                 break;
1326         case IPPROTO_SCTP:
1327                 poff += sizeof(struct sctphdr);
1328                 break;
1329         }
1330
1331         return poff;
1332 }
1333
1334 /**
1335  * skb_get_poff - get the offset to the payload
1336  * @skb: sk_buff to get the payload offset from
1337  *
1338  * The function will get the offset to the payload as far as it could
1339  * be dissected.  The main user is currently BPF, so that we can dynamically
1340  * truncate packets without needing to push actual payload to the user
1341  * space and can analyze headers only, instead.
1342  */
1343 u32 skb_get_poff(const struct sk_buff *skb)
1344 {
1345         struct flow_keys_basic keys;
1346
1347         if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
1348                 return 0;
1349
1350         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1351 }
1352
1353 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1354 {
1355         memset(keys, 0, sizeof(*keys));
1356
1357         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1358             sizeof(keys->addrs.v6addrs.src));
1359         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1360             sizeof(keys->addrs.v6addrs.dst));
1361         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1362         keys->ports.src = fl6->fl6_sport;
1363         keys->ports.dst = fl6->fl6_dport;
1364         keys->keyid.keyid = fl6->fl6_gre_key;
1365         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1366         keys->basic.ip_proto = fl6->flowi6_proto;
1367
1368         return flow_hash_from_keys(keys);
1369 }
1370 EXPORT_SYMBOL(__get_hash_from_flowi6);
1371
1372 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1373         {
1374                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1375                 .offset = offsetof(struct flow_keys, control),
1376         },
1377         {
1378                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1379                 .offset = offsetof(struct flow_keys, basic),
1380         },
1381         {
1382                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1383                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1384         },
1385         {
1386                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1387                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1388         },
1389         {
1390                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1391                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1392         },
1393         {
1394                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1395                 .offset = offsetof(struct flow_keys, ports),
1396         },
1397         {
1398                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1399                 .offset = offsetof(struct flow_keys, vlan),
1400         },
1401         {
1402                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1403                 .offset = offsetof(struct flow_keys, tags),
1404         },
1405         {
1406                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1407                 .offset = offsetof(struct flow_keys, keyid),
1408         },
1409 };
1410
1411 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1412         {
1413                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1414                 .offset = offsetof(struct flow_keys, control),
1415         },
1416         {
1417                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1418                 .offset = offsetof(struct flow_keys, basic),
1419         },
1420         {
1421                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1422                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1423         },
1424         {
1425                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1426                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1427         },
1428         {
1429                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1430                 .offset = offsetof(struct flow_keys, ports),
1431         },
1432 };
1433
1434 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1435         {
1436                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1437                 .offset = offsetof(struct flow_keys, control),
1438         },
1439         {
1440                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1441                 .offset = offsetof(struct flow_keys, basic),
1442         },
1443 };
1444
1445 struct flow_dissector flow_keys_dissector __read_mostly;
1446 EXPORT_SYMBOL(flow_keys_dissector);
1447
1448 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1449 EXPORT_SYMBOL(flow_keys_basic_dissector);
1450
1451 static int __init init_default_flow_dissectors(void)
1452 {
1453         skb_flow_dissector_init(&flow_keys_dissector,
1454                                 flow_keys_dissector_keys,
1455                                 ARRAY_SIZE(flow_keys_dissector_keys));
1456         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1457                                 flow_keys_dissector_symmetric_keys,
1458                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1459         skb_flow_dissector_init(&flow_keys_basic_dissector,
1460                                 flow_keys_basic_dissector_keys,
1461                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1462         return 0;
1463 }
1464
1465 core_initcall(init_default_flow_dissectors);