net/core/flow_dissector.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/kernel.h>
   3 #include <linux/skbuff.h>
   4 #include <linux/export.h>
   5 #include <linux/ip.h>
   6 #include <linux/ipv6.h>
   7 #include <linux/if_vlan.h>
   8 #include <net/dsa.h>
   9 #include <net/dst_metadata.h>
  10 #include <net/ip.h>
  11 #include <net/ipv6.h>
  12 #include <net/gre.h>
  13 #include <net/pptp.h>
  14 #include <net/tipc.h>
  15 #include <linux/igmp.h>
  16 #include <linux/icmp.h>
  17 #include <linux/sctp.h>
  18 #include <linux/dccp.h>
  19 #include <linux/if_tunnel.h>
  20 #include <linux/if_pppox.h>
  21 #include <linux/ppp_defs.h>
  22 #include <linux/stddef.h>
  23 #include <linux/if_ether.h>
  24 #include <linux/mpls.h>
  25 #include <linux/tcp.h>
  26 #include <net/flow_dissector.h>
  27 #include <scsi/fc/fc_fcoe.h>
  28 #include <uapi/linux/batadv_packet.h>
  29 #include <linux/bpf.h>
  30 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  31 #include <net/netfilter/nf_conntrack_core.h>
  32 #include <net/netfilter/nf_conntrack_labels.h>
  33 #endif
  34
  35 static DEFINE_MUTEX(flow_dissector_mutex);
  36
  37 static void dissector_set_key(struct flow_dissector *flow_dissector,
  38                               enum flow_dissector_key_id key_id)
  39 {
  40         flow_dissector->used_keys |= (1 << key_id);
  41 }
  42
  43 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  44                              const struct flow_dissector_key *key,
  45                              unsigned int key_count)
  46 {
  47         unsigned int i;
  48
  49         memset(flow_dissector, 0, sizeof(*flow_dissector));
  50
  51         for (i = 0; i < key_count; i++, key++) {
  52                 /* User should make sure that every key target offset is withing
  53                  * boundaries of unsigned short.
  54                  */
  55                 BUG_ON(key->offset > USHRT_MAX);
  56                 BUG_ON(dissector_uses_key(flow_dissector,
  57                                           key->key_id));
  58
  59                 dissector_set_key(flow_dissector, key->key_id);
  60                 flow_dissector->offset[key->key_id] = key->offset;
  61         }
  62
  63         /* Ensure that the dissector always includes control and basic key.
  64          * That way we are able to avoid handling lack of these in fast path.
  65          */
  66         BUG_ON(!dissector_uses_key(flow_dissector,
  67                                    FLOW_DISSECTOR_KEY_CONTROL));
  68         BUG_ON(!dissector_uses_key(flow_dissector,
  69                                    FLOW_DISSECTOR_KEY_BASIC));
  70 }
  71 EXPORT_SYMBOL(skb_flow_dissector_init);
  72
  73 int skb_flow_dissector_prog_query(const union bpf_attr *attr,
  74                                   union bpf_attr __user *uattr)
  75 {
  76         __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
  77         u32 prog_id, prog_cnt = 0, flags = 0;
  78         struct bpf_prog *attached;
  79         struct net *net;
  80
  81         if (attr->query.query_flags)
  82                 return -EINVAL;
  83
  84         net = get_net_ns_by_fd(attr->query.target_fd);
  85         if (IS_ERR(net))
  86                 return PTR_ERR(net);
  87
  88         rcu_read_lock();
  89         attached = rcu_dereference(net->flow_dissector_prog);
  90         if (attached) {
  91                 prog_cnt = 1;
  92                 prog_id = attached->aux->id;
  93         }
  94         rcu_read_unlock();
  95
  96         put_net(net);
  97
  98         if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
  99                 return -EFAULT;
 100         if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
 101                 return -EFAULT;
 102
 103         if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
 104                 return 0;
 105
 106         if (copy_to_user(prog_ids, &prog_id, sizeof(u32)))
 107                 return -EFAULT;
 108
 109         return 0;
 110 }
 111
 112 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
 113                                        struct bpf_prog *prog)
 114 {
 115         struct bpf_prog *attached;
 116         struct net *net;
 117
 118         net = current->nsproxy->net_ns;
 119         mutex_lock(&flow_dissector_mutex);
 120         attached = rcu_dereference_protected(net->flow_dissector_prog,
 121                                              lockdep_is_held(&flow_dissector_mutex));
 122         if (attached) {
 123                 /* Only one BPF program can be attached at a time */
 124                 mutex_unlock(&flow_dissector_mutex);
 125                 return -EEXIST;
 126         }
 127         rcu_assign_pointer(net->flow_dissector_prog, prog);
 128         mutex_unlock(&flow_dissector_mutex);
 129         return 0;
 130 }
 131
 132 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
 133 {
 134         struct bpf_prog *attached;
 135         struct net *net;
 136
 137         net = current->nsproxy->net_ns;
 138         mutex_lock(&flow_dissector_mutex);
 139         attached = rcu_dereference_protected(net->flow_dissector_prog,
 140                                              lockdep_is_held(&flow_dissector_mutex));
 141         if (!attached) {
 142                 mutex_unlock(&flow_dissector_mutex);
 143                 return -ENOENT;
 144         }
 145         RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
 146         bpf_prog_put(attached);
 147         mutex_unlock(&flow_dissector_mutex);
 148         return 0;
 149 }
 150 /**
 151  * skb_flow_get_be16 - extract be16 entity
 152  * @skb: sk_buff to extract from
 153  * @poff: offset to extract at
 154  * @data: raw buffer pointer to the packet
 155  * @hlen: packet header length
 156  *
 157  * The function will try to retrieve a be32 entity at
 158  * offset poff
 159  */
 160 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
 161                                 void *data, int hlen)
 162 {
 163         __be16 *u, _u;
 164
 165         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
 166         if (u)
 167                 return *u;
 168
 169         return 0;
 170 }
 171
 172 /**
 173  * __skb_flow_get_ports - extract the upper layer ports and return them
 174  * @skb: sk_buff to extract the ports from
 175  * @thoff: transport header offset
 176  * @ip_proto: protocol for which to get port offset
 177  * @data: raw buffer pointer to the packet, if NULL use skb->data
 178  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 179  *
 180  * The function will try to retrieve the ports at offset thoff + poff where poff
 181  * is the protocol port offset returned from proto_ports_offset
 182  */
 183 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
 184                             void *data, int hlen)
 185 {
 186         int poff = proto_ports_offset(ip_proto);
 187
 188         if (!data) {
 189                 data = skb->data;
 190                 hlen = skb_headlen(skb);
 191         }
 192
 193         if (poff >= 0) {
 194                 __be32 *ports, _ports;
 195
 196                 ports = __skb_header_pointer(skb, thoff + poff,
 197                                              sizeof(_ports), data, hlen, &_ports);
 198                 if (ports)
 199                         return *ports;
 200         }
 201
 202         return 0;
 203 }
 204 EXPORT_SYMBOL(__skb_flow_get_ports);
 205
 206 void skb_flow_dissect_meta(const struct sk_buff *skb,
 207                            struct flow_dissector *flow_dissector,
 208                            void *target_container)
 209 {
 210         struct flow_dissector_key_meta *meta;
 211
 212         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
 213                 return;
 214
 215         meta = skb_flow_dissector_target(flow_dissector,
 216                                          FLOW_DISSECTOR_KEY_META,
 217                                          target_container);
 218         meta->ingress_ifindex = skb->skb_iif;
 219 }
 220 EXPORT_SYMBOL(skb_flow_dissect_meta);
 221
 222 static void
 223 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
 224                                    struct flow_dissector *flow_dissector,
 225                                    void *target_container)
 226 {
 227         struct flow_dissector_key_control *ctrl;
 228
 229         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
 230                 return;
 231
 232         ctrl = skb_flow_dissector_target(flow_dissector,
 233                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
 234                                          target_container);
 235         ctrl->addr_type = type;
 236 }
 237
 238 void
 239 skb_flow_dissect_ct(const struct sk_buff *skb,
 240                     struct flow_dissector *flow_dissector,
 241                     void *target_container,
 242                     u16 *ctinfo_map,
 243                     size_t mapsize)
 244 {
 245 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 246         struct flow_dissector_key_ct *key;
 247         enum ip_conntrack_info ctinfo;
 248         struct nf_conn_labels *cl;
 249         struct nf_conn *ct;
 250
 251         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
 252                 return;
 253
 254         ct = nf_ct_get(skb, &ctinfo);
 255         if (!ct)
 256                 return;
 257
 258         key = skb_flow_dissector_target(flow_dissector,
 259                                         FLOW_DISSECTOR_KEY_CT,
 260                                         target_container);
 261
 262         if (ctinfo < mapsize)
 263                 key->ct_state = ctinfo_map[ctinfo];
 264 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
 265         key->ct_zone = ct->zone.id;
 266 #endif
 267 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 268         key->ct_mark = ct->mark;
 269 #endif
 270
 271         cl = nf_ct_labels_find(ct);
 272         if (cl)
 273                 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
 274 #endif /* CONFIG_NF_CONNTRACK */
 275 }
 276 EXPORT_SYMBOL(skb_flow_dissect_ct);
 277
 278 void
 279 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
 280                              struct flow_dissector *flow_dissector,
 281                              void *target_container)
 282 {
 283         struct ip_tunnel_info *info;
 284         struct ip_tunnel_key *key;
 285
 286         /* A quick check to see if there might be something to do. */
 287         if (!dissector_uses_key(flow_dissector,
 288                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
 289             !dissector_uses_key(flow_dissector,
 290                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
 291             !dissector_uses_key(flow_dissector,
 292                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
 293             !dissector_uses_key(flow_dissector,
 294                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
 295             !dissector_uses_key(flow_dissector,
 296                                 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
 297             !dissector_uses_key(flow_dissector,
 298                                 FLOW_DISSECTOR_KEY_ENC_IP) &&
 299             !dissector_uses_key(flow_dissector,
 300                                 FLOW_DISSECTOR_KEY_ENC_OPTS))
 301                 return;
 302
 303         info = skb_tunnel_info(skb);
 304         if (!info)
 305                 return;
 306
 307         key = &info->key;
 308
 309         switch (ip_tunnel_info_af(info)) {
 310         case AF_INET:
 311                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 312                                                    flow_dissector,
 313                                                    target_container);
 314                 if (dissector_uses_key(flow_dissector,
 315                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 316                         struct flow_dissector_key_ipv4_addrs *ipv4;
 317
 318                         ipv4 = skb_flow_dissector_target(flow_dissector,
 319                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 320                                                          target_container);
 321                         ipv4->src = key->u.ipv4.src;
 322                         ipv4->dst = key->u.ipv4.dst;
 323                 }
 324                 break;
 325         case AF_INET6:
 326                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 327                                                    flow_dissector,
 328                                                    target_container);
 329                 if (dissector_uses_key(flow_dissector,
 330                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 331                         struct flow_dissector_key_ipv6_addrs *ipv6;
 332
 333                         ipv6 = skb_flow_dissector_target(flow_dissector,
 334                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 335                                                          target_container);
 336                         ipv6->src = key->u.ipv6.src;
 337                         ipv6->dst = key->u.ipv6.dst;
 338                 }
 339                 break;
 340         }
 341
 342         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 343                 struct flow_dissector_key_keyid *keyid;
 344
 345                 keyid = skb_flow_dissector_target(flow_dissector,
 346                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
 347                                                   target_container);
 348                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
 349         }
 350
 351         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 352                 struct flow_dissector_key_ports *tp;
 353
 354                 tp = skb_flow_dissector_target(flow_dissector,
 355                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
 356                                                target_container);
 357                 tp->src = key->tp_src;
 358                 tp->dst = key->tp_dst;
 359         }
 360
 361         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
 362                 struct flow_dissector_key_ip *ip;
 363
 364                 ip = skb_flow_dissector_target(flow_dissector,
 365                                                FLOW_DISSECTOR_KEY_ENC_IP,
 366                                                target_container);
 367                 ip->tos = key->tos;
 368                 ip->ttl = key->ttl;
 369         }
 370
 371         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
 372                 struct flow_dissector_key_enc_opts *enc_opt;
 373
 374                 enc_opt = skb_flow_dissector_target(flow_dissector,
 375                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
 376                                                     target_container);
 377
 378                 if (info->options_len) {
 379                         enc_opt->len = info->options_len;
 380                         ip_tunnel_info_opts_get(enc_opt->data, info);
 381                         enc_opt->dst_opt_type = info->key.tun_flags &
 382                                                 TUNNEL_OPTIONS_PRESENT;
 383                 }
 384         }
 385 }
 386 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 387
 388 static enum flow_dissect_ret
 389 __skb_flow_dissect_mpls(const struct sk_buff *skb,
 390                         struct flow_dissector *flow_dissector,
 391                         void *target_container, void *data, int nhoff, int hlen)
 392 {
 393         struct flow_dissector_key_keyid *key_keyid;
 394         struct mpls_label *hdr, _hdr[2];
 395         u32 entry, label;
 396
 397         if (!dissector_uses_key(flow_dissector,
 398                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 399             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 400                 return FLOW_DISSECT_RET_OUT_GOOD;
 401
 402         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 403                                    hlen, &_hdr);
 404         if (!hdr)
 405                 return FLOW_DISSECT_RET_OUT_BAD;
 406
 407         entry = ntohl(hdr[0].entry);
 408         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 409
 410         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 411                 struct flow_dissector_key_mpls *key_mpls;
 412
 413                 key_mpls = skb_flow_dissector_target(flow_dissector,
 414                                                      FLOW_DISSECTOR_KEY_MPLS,
 415                                                      target_container);
 416                 key_mpls->mpls_label = label;
 417                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
 418                                         >> MPLS_LS_TTL_SHIFT;
 419                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
 420                                         >> MPLS_LS_TC_SHIFT;
 421                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
 422                                         >> MPLS_LS_S_SHIFT;
 423         }
 424
 425         if (label == MPLS_LABEL_ENTROPY) {
 426                 key_keyid = skb_flow_dissector_target(flow_dissector,
 427                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 428                                                       target_container);
 429                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
 430         }
 431         return FLOW_DISSECT_RET_OUT_GOOD;
 432 }
 433
 434 static enum flow_dissect_ret
 435 __skb_flow_dissect_arp(const struct sk_buff *skb,
 436                        struct flow_dissector *flow_dissector,
 437                        void *target_container, void *data, int nhoff, int hlen)
 438 {
 439         struct flow_dissector_key_arp *key_arp;
 440         struct {
 441                 unsigned char ar_sha[ETH_ALEN];
 442                 unsigned char ar_sip[4];
 443                 unsigned char ar_tha[ETH_ALEN];
 444                 unsigned char ar_tip[4];
 445         } *arp_eth, _arp_eth;
 446         const struct arphdr *arp;
 447         struct arphdr _arp;
 448
 449         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 450                 return FLOW_DISSECT_RET_OUT_GOOD;
 451
 452         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 453                                    hlen, &_arp);
 454         if (!arp)
 455                 return FLOW_DISSECT_RET_OUT_BAD;
 456
 457         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 458             arp->ar_pro != htons(ETH_P_IP) ||
 459             arp->ar_hln != ETH_ALEN ||
 460             arp->ar_pln != 4 ||
 461             (arp->ar_op != htons(ARPOP_REPLY) &&
 462              arp->ar_op != htons(ARPOP_REQUEST)))
 463                 return FLOW_DISSECT_RET_OUT_BAD;
 464
 465         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 466                                        sizeof(_arp_eth), data,
 467                                        hlen, &_arp_eth);
 468         if (!arp_eth)
 469                 return FLOW_DISSECT_RET_OUT_BAD;
 470
 471         key_arp = skb_flow_dissector_target(flow_dissector,
 472                                             FLOW_DISSECTOR_KEY_ARP,
 473                                             target_container);
 474
 475         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 476         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 477
 478         /* Only store the lower byte of the opcode;
 479          * this covers ARPOP_REPLY and ARPOP_REQUEST.
 480          */
 481         key_arp->op = ntohs(arp->ar_op) & 0xff;
 482
 483         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 484         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 485
 486         return FLOW_DISSECT_RET_OUT_GOOD;
 487 }
 488
 489 static enum flow_dissect_ret
 490 __skb_flow_dissect_gre(const struct sk_buff *skb,
 491                        struct flow_dissector_key_control *key_control,
 492                        struct flow_dissector *flow_dissector,
 493                        void *target_container, void *data,
 494                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
 495                        unsigned int flags)
 496 {
 497         struct flow_dissector_key_keyid *key_keyid;
 498         struct gre_base_hdr *hdr, _hdr;
 499         int offset = 0;
 500         u16 gre_ver;
 501
 502         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 503                                    data, *p_hlen, &_hdr);
 504         if (!hdr)
 505                 return FLOW_DISSECT_RET_OUT_BAD;
 506
 507         /* Only look inside GRE without routing */
 508         if (hdr->flags & GRE_ROUTING)
 509                 return FLOW_DISSECT_RET_OUT_GOOD;
 510
 511         /* Only look inside GRE for version 0 and 1 */
 512         gre_ver = ntohs(hdr->flags & GRE_VERSION);
 513         if (gre_ver > 1)
 514                 return FLOW_DISSECT_RET_OUT_GOOD;
 515
 516         *p_proto = hdr->protocol;
 517         if (gre_ver) {
 518                 /* Version1 must be PPTP, and check the flags */
 519                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 520                         return FLOW_DISSECT_RET_OUT_GOOD;
 521         }
 522
 523         offset += sizeof(struct gre_base_hdr);
 524
 525         if (hdr->flags & GRE_CSUM)
 526                 offset += FIELD_SIZEOF(struct gre_full_hdr, csum) +
 527                           FIELD_SIZEOF(struct gre_full_hdr, reserved1);
 528
 529         if (hdr->flags & GRE_KEY) {
 530                 const __be32 *keyid;
 531                 __be32 _keyid;
 532
 533                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 534                                              sizeof(_keyid),
 535                                              data, *p_hlen, &_keyid);
 536                 if (!keyid)
 537                         return FLOW_DISSECT_RET_OUT_BAD;
 538
 539                 if (dissector_uses_key(flow_dissector,
 540                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 541                         key_keyid = skb_flow_dissector_target(flow_dissector,
 542                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
 543                                                               target_container);
 544                         if (gre_ver == 0)
 545                                 key_keyid->keyid = *keyid;
 546                         else
 547                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 548                 }
 549                 offset += FIELD_SIZEOF(struct gre_full_hdr, key);
 550         }
 551
 552         if (hdr->flags & GRE_SEQ)
 553                 offset += FIELD_SIZEOF(struct pptp_gre_header, seq);
 554
 555         if (gre_ver == 0) {
 556                 if (*p_proto == htons(ETH_P_TEB)) {
 557                         const struct ethhdr *eth;
 558                         struct ethhdr _eth;
 559
 560                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
 561                                                    sizeof(_eth),
 562                                                    data, *p_hlen, &_eth);
 563                         if (!eth)
 564                                 return FLOW_DISSECT_RET_OUT_BAD;
 565                         *p_proto = eth->h_proto;
 566                         offset += sizeof(*eth);
 567
 568                         /* Cap headers that we access via pointers at the
 569                          * end of the Ethernet header as our maximum alignment
 570                          * at that point is only 2 bytes.
 571                          */
 572                         if (NET_IP_ALIGN)
 573                                 *p_hlen = *p_nhoff + offset;
 574                 }
 575         } else { /* version 1, must be PPTP */
 576                 u8 _ppp_hdr[PPP_HDRLEN];
 577                 u8 *ppp_hdr;
 578
 579                 if (hdr->flags & GRE_ACK)
 580                         offset += FIELD_SIZEOF(struct pptp_gre_header, ack);
 581
 582                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 583                                                sizeof(_ppp_hdr),
 584                                                data, *p_hlen, _ppp_hdr);
 585                 if (!ppp_hdr)
 586                         return FLOW_DISSECT_RET_OUT_BAD;
 587
 588                 switch (PPP_PROTOCOL(ppp_hdr)) {
 589                 case PPP_IP:
 590                         *p_proto = htons(ETH_P_IP);
 591                         break;
 592                 case PPP_IPV6:
 593                         *p_proto = htons(ETH_P_IPV6);
 594                         break;
 595                 default:
 596                         /* Could probably catch some more like MPLS */
 597                         break;
 598                 }
 599
 600                 offset += PPP_HDRLEN;
 601         }
 602
 603         *p_nhoff += offset;
 604         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 605         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 606                 return FLOW_DISSECT_RET_OUT_GOOD;
 607
 608         return FLOW_DISSECT_RET_PROTO_AGAIN;
 609 }
 610
 611 /**
 612  * __skb_flow_dissect_batadv() - dissect batman-adv header
 613  * @skb: sk_buff to with the batman-adv header
 614  * @key_control: flow dissectors control key
 615  * @data: raw buffer pointer to the packet, if NULL use skb->data
 616  * @p_proto: pointer used to update the protocol to process next
 617  * @p_nhoff: pointer used to update inner network header offset
 618  * @hlen: packet header length
 619  * @flags: any combination of FLOW_DISSECTOR_F_*
 620  *
 621  * ETH_P_BATMAN packets are tried to be dissected. Only
 622  * &struct batadv_unicast packets are actually processed because they contain an
 623  * inner ethernet header and are usually followed by actual network header. This
 624  * allows the flow dissector to continue processing the packet.
 625  *
 626  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 627  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 628  *  otherwise FLOW_DISSECT_RET_OUT_BAD
 629  */
 630 static enum flow_dissect_ret
 631 __skb_flow_dissect_batadv(const struct sk_buff *skb,
 632                           struct flow_dissector_key_control *key_control,
 633                           void *data, __be16 *p_proto, int *p_nhoff, int hlen,
 634                           unsigned int flags)
 635 {
 636         struct {
 637                 struct batadv_unicast_packet batadv_unicast;
 638                 struct ethhdr eth;
 639         } *hdr, _hdr;
 640
 641         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 642                                    &_hdr);
 643         if (!hdr)
 644                 return FLOW_DISSECT_RET_OUT_BAD;
 645
 646         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 647                 return FLOW_DISSECT_RET_OUT_BAD;
 648
 649         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 650                 return FLOW_DISSECT_RET_OUT_BAD;
 651
 652         *p_proto = hdr->eth.h_proto;
 653         *p_nhoff += sizeof(*hdr);
 654
 655         key_control->flags |= FLOW_DIS_ENCAPSULATION;
 656         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 657                 return FLOW_DISSECT_RET_OUT_GOOD;
 658
 659         return FLOW_DISSECT_RET_PROTO_AGAIN;
 660 }
 661
 662 static void
 663 __skb_flow_dissect_tcp(const struct sk_buff *skb,
 664                        struct flow_dissector *flow_dissector,
 665                        void *target_container, void *data, int thoff, int hlen)
 666 {
 667         struct flow_dissector_key_tcp *key_tcp;
 668         struct tcphdr *th, _th;
 669
 670         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 671                 return;
 672
 673         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 674         if (!th)
 675                 return;
 676
 677         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 678                 return;
 679
 680         key_tcp = skb_flow_dissector_target(flow_dissector,
 681                                             FLOW_DISSECTOR_KEY_TCP,
 682                                             target_container);
 683         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 684 }
 685
 686 static void
 687 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
 688                         struct flow_dissector *flow_dissector,
 689                         void *target_container, void *data, const struct iphdr *iph)
 690 {
 691         struct flow_dissector_key_ip *key_ip;
 692
 693         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 694                 return;
 695
 696         key_ip = skb_flow_dissector_target(flow_dissector,
 697                                            FLOW_DISSECTOR_KEY_IP,
 698                                            target_container);
 699         key_ip->tos = iph->tos;
 700         key_ip->ttl = iph->ttl;
 701 }
 702
 703 static void
 704 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
 705                         struct flow_dissector *flow_dissector,
 706                         void *target_container, void *data, const struct ipv6hdr *iph)
 707 {
 708         struct flow_dissector_key_ip *key_ip;
 709
 710         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 711                 return;
 712
 713         key_ip = skb_flow_dissector_target(flow_dissector,
 714                                            FLOW_DISSECTOR_KEY_IP,
 715                                            target_container);
 716         key_ip->tos = ipv6_get_dsfield(iph);
 717         key_ip->ttl = iph->hop_limit;
 718 }
 719
 720 /* Maximum number of protocol headers that can be parsed in
 721  * __skb_flow_dissect
 722  */
 723 #define MAX_FLOW_DISSECT_HDRS   15
 724
 725 static bool skb_flow_dissect_allowed(int *num_hdrs)
 726 {
 727         ++*num_hdrs;
 728
 729         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 730 }
 731
 732 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
 733                                      struct flow_dissector *flow_dissector,
 734                                      void *target_container)
 735 {
 736         struct flow_dissector_key_control *key_control;
 737         struct flow_dissector_key_basic *key_basic;
 738         struct flow_dissector_key_addrs *key_addrs;
 739         struct flow_dissector_key_ports *key_ports;
 740
 741         key_control = skb_flow_dissector_target(flow_dissector,
 742                                                 FLOW_DISSECTOR_KEY_CONTROL,
 743                                                 target_container);
 744         key_control->thoff = flow_keys->thoff;
 745         if (flow_keys->is_frag)
 746                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 747         if (flow_keys->is_first_frag)
 748                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 749         if (flow_keys->is_encap)
 750                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
 751
 752         key_basic = skb_flow_dissector_target(flow_dissector,
 753                                               FLOW_DISSECTOR_KEY_BASIC,
 754                                               target_container);
 755         key_basic->n_proto = flow_keys->n_proto;
 756         key_basic->ip_proto = flow_keys->ip_proto;
 757
 758         if (flow_keys->addr_proto == ETH_P_IP &&
 759             dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 760                 key_addrs = skb_flow_dissector_target(flow_dissector,
 761                                                       FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 762                                                       target_container);
 763                 key_addrs->v4addrs.src = flow_keys->ipv4_src;
 764                 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
 765                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 766         } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
 767                    dissector_uses_key(flow_dissector,
 768                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 769                 key_addrs = skb_flow_dissector_target(flow_dissector,
 770                                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 771                                                       target_container);
 772                 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
 773                        sizeof(key_addrs->v6addrs));
 774                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 775         }
 776
 777         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
 778                 key_ports = skb_flow_dissector_target(flow_dissector,
 779                                                       FLOW_DISSECTOR_KEY_PORTS,
 780                                                       target_container);
 781                 key_ports->src = flow_keys->sport;
 782                 key_ports->dst = flow_keys->dport;
 783         }
 784 }
 785
 786 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
 787                       __be16 proto, int nhoff, int hlen)
 788 {
 789         struct bpf_flow_keys *flow_keys = ctx->flow_keys;
 790         u32 result;
 791
 792         /* Pass parameters to the BPF program */
 793         memset(flow_keys, 0, sizeof(*flow_keys));
 794         flow_keys->n_proto = proto;
 795         flow_keys->nhoff = nhoff;
 796         flow_keys->thoff = flow_keys->nhoff;
 797
 798         preempt_disable();
 799         result = BPF_PROG_RUN(prog, ctx);
 800         preempt_enable();
 801
 802         flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
 803         flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
 804                                    flow_keys->nhoff, hlen);
 805
 806         return result == BPF_OK;
 807 }
 808
 809 /**
 810  * __skb_flow_dissect - extract the flow_keys struct and return it
 811  * @net: associated network namespace, derived from @skb if NULL
 812  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 813  * @flow_dissector: list of keys to dissect
 814  * @target_container: target structure to put dissected values into
 815  * @data: raw buffer pointer to the packet, if NULL use skb->data
 816  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 817  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 818  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 819  * @flags: flags that control the dissection process, e.g.
 820  *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
 821  *
 822  * The function will try to retrieve individual keys into target specified
 823  * by flow_dissector from either the skbuff or a raw buffer specified by the
 824  * rest parameters.
 825  *
 826  * Caller must take care of zeroing target container memory.
 827  */
 828 bool __skb_flow_dissect(const struct net *net,
 829                         const struct sk_buff *skb,
 830                         struct flow_dissector *flow_dissector,
 831                         void *target_container,
 832                         void *data, __be16 proto, int nhoff, int hlen,
 833                         unsigned int flags)
 834 {
 835         struct flow_dissector_key_control *key_control;
 836         struct flow_dissector_key_basic *key_basic;
 837         struct flow_dissector_key_addrs *key_addrs;
 838         struct flow_dissector_key_ports *key_ports;
 839         struct flow_dissector_key_icmp *key_icmp;
 840         struct flow_dissector_key_tags *key_tags;
 841         struct flow_dissector_key_vlan *key_vlan;
 842         struct bpf_prog *attached = NULL;
 843         enum flow_dissect_ret fdret;
 844         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
 845         int num_hdrs = 0;
 846         u8 ip_proto = 0;
 847         bool ret;
 848
 849         if (!data) {
 850                 data = skb->data;
 851                 proto = skb_vlan_tag_present(skb) ?
 852                          skb->vlan_proto : skb->protocol;
 853                 nhoff = skb_network_offset(skb);
 854                 hlen = skb_headlen(skb);
 855 #if IS_ENABLED(CONFIG_NET_DSA)
 856                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
 857                         const struct dsa_device_ops *ops;
 858                         int offset;
 859
 860                         ops = skb->dev->dsa_ptr->tag_ops;
 861                         if (ops->flow_dissect &&
 862                             !ops->flow_dissect(skb, &proto, &offset)) {
 863                                 hlen -= offset;
 864                                 nhoff += offset;
 865                         }
 866                 }
 867 #endif
 868         }
 869
 870         /* It is ensured by skb_flow_dissector_init() that control key will
 871          * be always present.
 872          */
 873         key_control = skb_flow_dissector_target(flow_dissector,
 874                                                 FLOW_DISSECTOR_KEY_CONTROL,
 875                                                 target_container);
 876
 877         /* It is ensured by skb_flow_dissector_init() that basic key will
 878          * be always present.
 879          */
 880         key_basic = skb_flow_dissector_target(flow_dissector,
 881                                               FLOW_DISSECTOR_KEY_BASIC,
 882                                               target_container);
 883
 884         if (skb) {
 885                 if (!net) {
 886                         if (skb->dev)
 887                                 net = dev_net(skb->dev);
 888                         else if (skb->sk)
 889                                 net = sock_net(skb->sk);
 890                 }
 891         }
 892
 893         WARN_ON_ONCE(!net);
 894         if (net) {
 895                 rcu_read_lock();
 896                 attached = rcu_dereference(net->flow_dissector_prog);
 897
 898                 if (attached) {
 899                         struct bpf_flow_keys flow_keys;
 900                         struct bpf_flow_dissector ctx = {
 901                                 .flow_keys = &flow_keys,
 902                                 .data = data,
 903                                 .data_end = data + hlen,
 904                         };
 905                         __be16 n_proto = proto;
 906
 907                         if (skb) {
 908                                 ctx.skb = skb;
 909                                 /* we can't use 'proto' in the skb case
 910                                  * because it might be set to skb->vlan_proto
 911                                  * which has been pulled from the data
 912                                  */
 913                                 n_proto = skb->protocol;
 914                         }
 915
 916                         ret = bpf_flow_dissect(attached, &ctx, n_proto, nhoff,
 917                                                hlen);
 918                         __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
 919                                                  target_container);
 920                         rcu_read_unlock();
 921                         return ret;
 922                 }
 923                 rcu_read_unlock();
 924         }
 925
 926         if (dissector_uses_key(flow_dissector,
 927                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 928                 struct ethhdr *eth = eth_hdr(skb);
 929                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
 930
 931                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 932                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
 933                                                           target_container);
 934                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 935         }
 936
 937 proto_again:
 938         fdret = FLOW_DISSECT_RET_CONTINUE;
 939
 940         switch (proto) {
 941         case htons(ETH_P_IP): {
 942                 const struct iphdr *iph;
 943                 struct iphdr _iph;
 944
 945                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 946                 if (!iph || iph->ihl < 5) {
 947                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 948                         break;
 949                 }
 950
 951                 nhoff += iph->ihl * 4;
 952
 953                 ip_proto = iph->protocol;
 954
 955                 if (dissector_uses_key(flow_dissector,
 956                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 957                         key_addrs = skb_flow_dissector_target(flow_dissector,
 958                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 959                                                               target_container);
 960
 961                         memcpy(&key_addrs->v4addrs, &iph->saddr,
 962                                sizeof(key_addrs->v4addrs));
 963                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 964                 }
 965
 966                 if (ip_is_fragment(iph)) {
 967                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 968
 969                         if (iph->frag_off & htons(IP_OFFSET)) {
 970                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
 971                                 break;
 972                         } else {
 973                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
 974                                 if (!(flags &
 975                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
 976                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
 977                                         break;
 978                                 }
 979                         }
 980                 }
 981
 982                 __skb_flow_dissect_ipv4(skb, flow_dissector,
 983                                         target_container, data, iph);
 984
 985                 break;
 986         }
 987         case htons(ETH_P_IPV6): {
 988                 const struct ipv6hdr *iph;
 989                 struct ipv6hdr _iph;
 990
 991                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
 992                 if (!iph) {
 993                         fdret = FLOW_DISSECT_RET_OUT_BAD;
 994                         break;
 995                 }
 996
 997                 ip_proto = iph->nexthdr;
 998                 nhoff += sizeof(struct ipv6hdr);
 999
1000                 if (dissector_uses_key(flow_dissector,
1001                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1002                         key_addrs = skb_flow_dissector_target(flow_dissector,
1003                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1004                                                               target_container);
1005
1006                         memcpy(&key_addrs->v6addrs, &iph->saddr,
1007                                sizeof(key_addrs->v6addrs));
1008                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1009                 }
1010
1011                 if ((dissector_uses_key(flow_dissector,
1012                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1013                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1014                     ip6_flowlabel(iph)) {
1015                         __be32 flow_label = ip6_flowlabel(iph);
1016
1017                         if (dissector_uses_key(flow_dissector,
1018                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1019                                 key_tags = skb_flow_dissector_target(flow_dissector,
1020                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
1021                                                                      target_container);
1022                                 key_tags->flow_label = ntohl(flow_label);
1023                         }
1024                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1025                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1026                                 break;
1027                         }
1028                 }
1029
1030                 __skb_flow_dissect_ipv6(skb, flow_dissector,
1031                                         target_container, data, iph);
1032
1033                 break;
1034         }
1035         case htons(ETH_P_8021AD):
1036         case htons(ETH_P_8021Q): {
1037                 const struct vlan_hdr *vlan = NULL;
1038                 struct vlan_hdr _vlan;
1039                 __be16 saved_vlan_tpid = proto;
1040
1041                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1042                     skb && skb_vlan_tag_present(skb)) {
1043                         proto = skb->protocol;
1044                 } else {
1045                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1046                                                     data, hlen, &_vlan);
1047                         if (!vlan) {
1048                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1049                                 break;
1050                         }
1051
1052                         proto = vlan->h_vlan_encapsulated_proto;
1053                         nhoff += sizeof(*vlan);
1054                 }
1055
1056                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1057                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1058                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1059                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1060                 } else {
1061                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1062                         break;
1063                 }
1064
1065                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1066                         key_vlan = skb_flow_dissector_target(flow_dissector,
1067                                                              dissector_vlan,
1068                                                              target_container);
1069
1070                         if (!vlan) {
1071                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1072                                 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1073                         } else {
1074                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1075                                         VLAN_VID_MASK;
1076                                 key_vlan->vlan_priority =
1077                                         (ntohs(vlan->h_vlan_TCI) &
1078                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1079                         }
1080                         key_vlan->vlan_tpid = saved_vlan_tpid;
1081                 }
1082
1083                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1084                 break;
1085         }
1086         case htons(ETH_P_PPP_SES): {
1087                 struct {
1088                         struct pppoe_hdr hdr;
1089                         __be16 proto;
1090                 } *hdr, _hdr;
1091                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1092                 if (!hdr) {
1093                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1094                         break;
1095                 }
1096
1097                 proto = hdr->proto;
1098                 nhoff += PPPOE_SES_HLEN;
1099                 switch (proto) {
1100                 case htons(PPP_IP):
1101                         proto = htons(ETH_P_IP);
1102                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1103                         break;
1104                 case htons(PPP_IPV6):
1105                         proto = htons(ETH_P_IPV6);
1106                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1107                         break;
1108                 default:
1109                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1110                         break;
1111                 }
1112                 break;
1113         }
1114         case htons(ETH_P_TIPC): {
1115                 struct tipc_basic_hdr *hdr, _hdr;
1116
1117                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1118                                            data, hlen, &_hdr);
1119                 if (!hdr) {
1120                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1121                         break;
1122                 }
1123
1124                 if (dissector_uses_key(flow_dissector,
1125                                        FLOW_DISSECTOR_KEY_TIPC)) {
1126                         key_addrs = skb_flow_dissector_target(flow_dissector,
1127                                                               FLOW_DISSECTOR_KEY_TIPC,
1128                                                               target_container);
1129                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1130                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1131                 }
1132                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1133                 break;
1134         }
1135
1136         case htons(ETH_P_MPLS_UC):
1137         case htons(ETH_P_MPLS_MC):
1138                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1139                                                 target_container, data,
1140                                                 nhoff, hlen);
1141                 break;
1142         case htons(ETH_P_FCOE):
1143                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1144                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1145                         break;
1146                 }
1147
1148                 nhoff += FCOE_HEADER_LEN;
1149                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1150                 break;
1151
1152         case htons(ETH_P_ARP):
1153         case htons(ETH_P_RARP):
1154                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1155                                                target_container, data,
1156                                                nhoff, hlen);
1157                 break;
1158
1159         case htons(ETH_P_BATMAN):
1160                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1161                                                   &proto, &nhoff, hlen, flags);
1162                 break;
1163
1164         default:
1165                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1166                 break;
1167         }
1168
1169         /* Process result of proto processing */
1170         switch (fdret) {
1171         case FLOW_DISSECT_RET_OUT_GOOD:
1172                 goto out_good;
1173         case FLOW_DISSECT_RET_PROTO_AGAIN:
1174                 if (skb_flow_dissect_allowed(&num_hdrs))
1175                         goto proto_again;
1176                 goto out_good;
1177         case FLOW_DISSECT_RET_CONTINUE:
1178         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1179                 break;
1180         case FLOW_DISSECT_RET_OUT_BAD:
1181         default:
1182                 goto out_bad;
1183         }
1184
1185 ip_proto_again:
1186         fdret = FLOW_DISSECT_RET_CONTINUE;
1187
1188         switch (ip_proto) {
1189         case IPPROTO_GRE:
1190                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1191                                                target_container, data,
1192                                                &proto, &nhoff, &hlen, flags);
1193                 break;
1194
1195         case NEXTHDR_HOP:
1196         case NEXTHDR_ROUTING:
1197         case NEXTHDR_DEST: {
1198                 u8 _opthdr[2], *opthdr;
1199
1200                 if (proto != htons(ETH_P_IPV6))
1201                         break;
1202
1203                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1204                                               data, hlen, &_opthdr);
1205                 if (!opthdr) {
1206                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1207                         break;
1208                 }
1209
1210                 ip_proto = opthdr[0];
1211                 nhoff += (opthdr[1] + 1) << 3;
1212
1213                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1214                 break;
1215         }
1216         case NEXTHDR_FRAGMENT: {
1217                 struct frag_hdr _fh, *fh;
1218
1219                 if (proto != htons(ETH_P_IPV6))
1220                         break;
1221
1222                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1223                                           data, hlen, &_fh);
1224
1225                 if (!fh) {
1226                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1227                         break;
1228                 }
1229
1230                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1231
1232                 nhoff += sizeof(_fh);
1233                 ip_proto = fh->nexthdr;
1234
1235                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1236                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
1237                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1238                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1239                                 break;
1240                         }
1241                 }
1242
1243                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1244                 break;
1245         }
1246         case IPPROTO_IPIP:
1247                 proto = htons(ETH_P_IP);
1248
1249                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1250                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1251                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1252                         break;
1253                 }
1254
1255                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1256                 break;
1257
1258         case IPPROTO_IPV6:
1259                 proto = htons(ETH_P_IPV6);
1260
1261                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1262                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1263                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1264                         break;
1265                 }
1266
1267                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1268                 break;
1269
1270
1271         case IPPROTO_MPLS:
1272                 proto = htons(ETH_P_MPLS_UC);
1273                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1274                 break;
1275
1276         case IPPROTO_TCP:
1277                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1278                                        data, nhoff, hlen);
1279                 break;
1280
1281         default:
1282                 break;
1283         }
1284
1285         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1286             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1287                 key_ports = skb_flow_dissector_target(flow_dissector,
1288                                                       FLOW_DISSECTOR_KEY_PORTS,
1289                                                       target_container);
1290                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1291                                                         data, hlen);
1292         }
1293
1294         if (dissector_uses_key(flow_dissector,
1295                                FLOW_DISSECTOR_KEY_ICMP)) {
1296                 key_icmp = skb_flow_dissector_target(flow_dissector,
1297                                                      FLOW_DISSECTOR_KEY_ICMP,
1298                                                      target_container);
1299                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1300         }
1301
1302         /* Process result of IP proto processing */
1303         switch (fdret) {
1304         case FLOW_DISSECT_RET_PROTO_AGAIN:
1305                 if (skb_flow_dissect_allowed(&num_hdrs))
1306                         goto proto_again;
1307                 break;
1308         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1309                 if (skb_flow_dissect_allowed(&num_hdrs))
1310                         goto ip_proto_again;
1311                 break;
1312         case FLOW_DISSECT_RET_OUT_GOOD:
1313         case FLOW_DISSECT_RET_CONTINUE:
1314                 break;
1315         case FLOW_DISSECT_RET_OUT_BAD:
1316         default:
1317                 goto out_bad;
1318         }
1319
1320 out_good:
1321         ret = true;
1322
1323 out:
1324         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1325         key_basic->n_proto = proto;
1326         key_basic->ip_proto = ip_proto;
1327
1328         return ret;
1329
1330 out_bad:
1331         ret = false;
1332         goto out;
1333 }
1334 EXPORT_SYMBOL(__skb_flow_dissect);
1335
1336 static u32 hashrnd __read_mostly;
1337 static __always_inline void __flow_hash_secret_init(void)
1338 {
1339         net_get_random_once(&hashrnd, sizeof(hashrnd));
1340 }
1341
1342 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
1343                                              u32 keyval)
1344 {
1345         return jhash2(words, length, keyval);
1346 }
1347
1348 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1349 {
1350         const void *p = flow;
1351
1352         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1353         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1354 }
1355
1356 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1357 {
1358         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1359         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1360         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1361                      sizeof(*flow) - sizeof(flow->addrs));
1362
1363         switch (flow->control.addr_type) {
1364         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1365                 diff -= sizeof(flow->addrs.v4addrs);
1366                 break;
1367         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1368                 diff -= sizeof(flow->addrs.v6addrs);
1369                 break;
1370         case FLOW_DISSECTOR_KEY_TIPC:
1371                 diff -= sizeof(flow->addrs.tipckey);
1372                 break;
1373         }
1374         return (sizeof(*flow) - diff) / sizeof(u32);
1375 }
1376
1377 __be32 flow_get_u32_src(const struct flow_keys *flow)
1378 {
1379         switch (flow->control.addr_type) {
1380         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1381                 return flow->addrs.v4addrs.src;
1382         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1383                 return (__force __be32)ipv6_addr_hash(
1384                         &flow->addrs.v6addrs.src);
1385         case FLOW_DISSECTOR_KEY_TIPC:
1386                 return flow->addrs.tipckey.key;
1387         default:
1388                 return 0;
1389         }
1390 }
1391 EXPORT_SYMBOL(flow_get_u32_src);
1392
1393 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1394 {
1395         switch (flow->control.addr_type) {
1396         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1397                 return flow->addrs.v4addrs.dst;
1398         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1399                 return (__force __be32)ipv6_addr_hash(
1400                         &flow->addrs.v6addrs.dst);
1401         default:
1402                 return 0;
1403         }
1404 }
1405 EXPORT_SYMBOL(flow_get_u32_dst);
1406
1407 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1408 {
1409         int addr_diff, i;
1410
1411         switch (keys->control.addr_type) {
1412         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1413                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1414                             (__force u32)keys->addrs.v4addrs.src;
1415                 if ((addr_diff < 0) ||
1416                     (addr_diff == 0 &&
1417                      ((__force u16)keys->ports.dst <
1418                       (__force u16)keys->ports.src))) {
1419                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1420                         swap(keys->ports.src, keys->ports.dst);
1421                 }
1422                 break;
1423         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1424                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1425                                    &keys->addrs.v6addrs.src,
1426                                    sizeof(keys->addrs.v6addrs.dst));
1427                 if ((addr_diff < 0) ||
1428                     (addr_diff == 0 &&
1429                      ((__force u16)keys->ports.dst <
1430                       (__force u16)keys->ports.src))) {
1431                         for (i = 0; i < 4; i++)
1432                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1433                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1434                         swap(keys->ports.src, keys->ports.dst);
1435                 }
1436                 break;
1437         }
1438 }
1439
1440 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1441 {
1442         u32 hash;
1443
1444         __flow_hash_consistentify(keys);
1445
1446         hash = __flow_hash_words(flow_keys_hash_start(keys),
1447                                  flow_keys_hash_length(keys), keyval);
1448         if (!hash)
1449                 hash = 1;
1450
1451         return hash;
1452 }
1453
1454 u32 flow_hash_from_keys(struct flow_keys *keys)
1455 {
1456         __flow_hash_secret_init();
1457         return __flow_hash_from_keys(keys, hashrnd);
1458 }
1459 EXPORT_SYMBOL(flow_hash_from_keys);
1460
1461 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1462                                   struct flow_keys *keys, u32 keyval)
1463 {
1464         skb_flow_dissect_flow_keys(skb, keys,
1465                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1466
1467         return __flow_hash_from_keys(keys, keyval);
1468 }
1469
1470 struct _flow_keys_digest_data {
1471         __be16  n_proto;
1472         u8      ip_proto;
1473         u8      padding;
1474         __be32  ports;
1475         __be32  src;
1476         __be32  dst;
1477 };
1478
1479 void make_flow_keys_digest(struct flow_keys_digest *digest,
1480                            const struct flow_keys *flow)
1481 {
1482         struct _flow_keys_digest_data *data =
1483             (struct _flow_keys_digest_data *)digest;
1484
1485         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1486
1487         memset(digest, 0, sizeof(*digest));
1488
1489         data->n_proto = flow->basic.n_proto;
1490         data->ip_proto = flow->basic.ip_proto;
1491         data->ports = flow->ports.ports;
1492         data->src = flow->addrs.v4addrs.src;
1493         data->dst = flow->addrs.v4addrs.dst;
1494 }
1495 EXPORT_SYMBOL(make_flow_keys_digest);
1496
1497 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1498
1499 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1500 {
1501         struct flow_keys keys;
1502
1503         __flow_hash_secret_init();
1504
1505         memset(&keys, 0, sizeof(keys));
1506         __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1507                            &keys, NULL, 0, 0, 0,
1508                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1509
1510         return __flow_hash_from_keys(&keys, hashrnd);
1511 }
1512 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1513
1514 /**
1515  * __skb_get_hash: calculate a flow hash
1516  * @skb: sk_buff to calculate flow hash from
1517  *
1518  * This function calculates a flow hash based on src/dst addresses
1519  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1520  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1521  * if hash is a canonical 4-tuple hash over transport ports.
1522  */
1523 void __skb_get_hash(struct sk_buff *skb)
1524 {
1525         struct flow_keys keys;
1526         u32 hash;
1527
1528         __flow_hash_secret_init();
1529
1530         hash = ___skb_get_hash(skb, &keys, hashrnd);
1531
1532         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1533 }
1534 EXPORT_SYMBOL(__skb_get_hash);
1535
1536 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1537 {
1538         struct flow_keys keys;
1539
1540         return ___skb_get_hash(skb, &keys, perturb);
1541 }
1542 EXPORT_SYMBOL(skb_get_hash_perturb);
1543
1544 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1545                    const struct flow_keys_basic *keys, int hlen)
1546 {
1547         u32 poff = keys->control.thoff;
1548
1549         /* skip L4 headers for fragments after the first */
1550         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1551             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1552                 return poff;
1553
1554         switch (keys->basic.ip_proto) {
1555         case IPPROTO_TCP: {
1556                 /* access doff as u8 to avoid unaligned access */
1557                 const u8 *doff;
1558                 u8 _doff;
1559
1560                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1561                                             data, hlen, &_doff);
1562                 if (!doff)
1563                         return poff;
1564
1565                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1566                 break;
1567         }
1568         case IPPROTO_UDP:
1569         case IPPROTO_UDPLITE:
1570                 poff += sizeof(struct udphdr);
1571                 break;
1572         /* For the rest, we do not really care about header
1573          * extensions at this point for now.
1574          */
1575         case IPPROTO_ICMP:
1576                 poff += sizeof(struct icmphdr);
1577                 break;
1578         case IPPROTO_ICMPV6:
1579                 poff += sizeof(struct icmp6hdr);
1580                 break;
1581         case IPPROTO_IGMP:
1582                 poff += sizeof(struct igmphdr);
1583                 break;
1584         case IPPROTO_DCCP:
1585                 poff += sizeof(struct dccp_hdr);
1586                 break;
1587         case IPPROTO_SCTP:
1588                 poff += sizeof(struct sctphdr);
1589                 break;
1590         }
1591
1592         return poff;
1593 }
1594
1595 /**
1596  * skb_get_poff - get the offset to the payload
1597  * @skb: sk_buff to get the payload offset from
1598  *
1599  * The function will get the offset to the payload as far as it could
1600  * be dissected.  The main user is currently BPF, so that we can dynamically
1601  * truncate packets without needing to push actual payload to the user
1602  * space and can analyze headers only, instead.
1603  */
1604 u32 skb_get_poff(const struct sk_buff *skb)
1605 {
1606         struct flow_keys_basic keys;
1607
1608         if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1609                                               NULL, 0, 0, 0, 0))
1610                 return 0;
1611
1612         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1613 }
1614
1615 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1616 {
1617         memset(keys, 0, sizeof(*keys));
1618
1619         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1620             sizeof(keys->addrs.v6addrs.src));
1621         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1622             sizeof(keys->addrs.v6addrs.dst));
1623         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1624         keys->ports.src = fl6->fl6_sport;
1625         keys->ports.dst = fl6->fl6_dport;
1626         keys->keyid.keyid = fl6->fl6_gre_key;
1627         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1628         keys->basic.ip_proto = fl6->flowi6_proto;
1629
1630         return flow_hash_from_keys(keys);
1631 }
1632 EXPORT_SYMBOL(__get_hash_from_flowi6);
1633
1634 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1635         {
1636                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1637                 .offset = offsetof(struct flow_keys, control),
1638         },
1639         {
1640                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1641                 .offset = offsetof(struct flow_keys, basic),
1642         },
1643         {
1644                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1645                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1646         },
1647         {
1648                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1649                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1650         },
1651         {
1652                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1653                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1654         },
1655         {
1656                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1657                 .offset = offsetof(struct flow_keys, ports),
1658         },
1659         {
1660                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1661                 .offset = offsetof(struct flow_keys, vlan),
1662         },
1663         {
1664                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1665                 .offset = offsetof(struct flow_keys, tags),
1666         },
1667         {
1668                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1669                 .offset = offsetof(struct flow_keys, keyid),
1670         },
1671 };
1672
1673 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1674         {
1675                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1676                 .offset = offsetof(struct flow_keys, control),
1677         },
1678         {
1679                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1680                 .offset = offsetof(struct flow_keys, basic),
1681         },
1682         {
1683                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1684                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1685         },
1686         {
1687                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1688                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1689         },
1690         {
1691                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1692                 .offset = offsetof(struct flow_keys, ports),
1693         },
1694 };
1695
1696 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1697         {
1698                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1699                 .offset = offsetof(struct flow_keys, control),
1700         },
1701         {
1702                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1703                 .offset = offsetof(struct flow_keys, basic),
1704         },
1705 };
1706
1707 struct flow_dissector flow_keys_dissector __read_mostly;
1708 EXPORT_SYMBOL(flow_keys_dissector);
1709
1710 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1711 EXPORT_SYMBOL(flow_keys_basic_dissector);
1712
1713 static int __init init_default_flow_dissectors(void)
1714 {
1715         skb_flow_dissector_init(&flow_keys_dissector,
1716                                 flow_keys_dissector_keys,
1717                                 ARRAY_SIZE(flow_keys_dissector_keys));
1718         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1719                                 flow_keys_dissector_symmetric_keys,
1720                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1721         skb_flow_dissector_init(&flow_keys_basic_dissector,
1722                                 flow_keys_basic_dissector_keys,
1723                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1724         return 0;
1725 }
1726
1727 core_initcall(init_default_flow_dissectors);