datapath/flow.c

   1 /*
   2  * Copyright (c) 2007-2013 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301, USA
  17  */
  18
  19 #include "flow.h"
  20 #include "datapath.h"
  21 #include <linux/uaccess.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/etherdevice.h>
  24 #include <linux/if_ether.h>
  25 #include <linux/if_vlan.h>
  26 #include <net/llc_pdu.h>
  27 #include <linux/kernel.h>
  28 #include <linux/jhash.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/llc.h>
  31 #include <linux/module.h>
  32 #include <linux/in.h>
  33 #include <linux/rcupdate.h>
  34 #include <linux/if_arp.h>
  35 #include <linux/ip.h>
  36 #include <linux/ipv6.h>
  37 #include <linux/sctp.h>
  38 #include <linux/smp.h>
  39 #include <linux/tcp.h>
  40 #include <linux/udp.h>
  41 #include <linux/icmp.h>
  42 #include <linux/icmpv6.h>
  43 #include <linux/rculist.h>
  44 #include <net/ip.h>
  45 #include <net/ipv6.h>
  46 #include <net/ndisc.h>
  47
  48 #include "vlan.h"
  49
  50 u64 ovs_flow_used_time(unsigned long flow_jiffies)
  51 {
  52         struct timespec cur_ts;
  53         u64 cur_ms, idle_ms;
  54
  55         ktime_get_ts(&cur_ts);
  56         idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
  57         cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
  58                  cur_ts.tv_nsec / NSEC_PER_MSEC;
  59
  60         return cur_ms - idle_ms;
  61 }
  62
  63 #define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))
  64
  65 void ovs_flow_stats_update(struct sw_flow *flow, struct sk_buff *skb)
  66 {
  67         struct flow_stats *stats;
  68         __be16 tcp_flags = 0;
  69         int node = numa_node_id();
  70
  71         stats = rcu_dereference(flow->stats[node]);
  72
  73         if ((flow->key.eth.type == htons(ETH_P_IP) ||
  74              flow->key.eth.type == htons(ETH_P_IPV6)) &&
  75             flow->key.ip.frag != OVS_FRAG_TYPE_LATER &&
  76             flow->key.ip.proto == IPPROTO_TCP &&
  77             likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
  78                 tcp_flags = TCP_FLAGS_BE16(tcp_hdr(skb));
  79         }
  80
  81         /* Check if already have node-specific stats. */
  82         if (likely(stats)) {
  83                 spin_lock(&stats->lock);
  84                 /* Mark if we write on the pre-allocated stats. */
  85                 if (node == 0 && unlikely(flow->stats_last_writer != node))
  86                         flow->stats_last_writer = node;
  87         } else {
  88                 stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
  89                 spin_lock(&stats->lock);
  90
  91                 /* If the current NUMA-node is the only writer on the
  92                  * pre-allocated stats keep using them.
  93                  */
  94                 if (unlikely(flow->stats_last_writer != node)) {
  95                         /* A previous locker may have already allocated the
  96                          * stats, so we need to check again.  If node-specific
  97                          * stats were already allocated, we update the pre-
  98                          * allocated stats as we have already locked them.
  99                          */
 100                         if (likely(flow->stats_last_writer != NUMA_NO_NODE)
 101                             && likely(!rcu_dereference(flow->stats[node]))) {
 102                                 /* Try to allocate node-specific stats. */
 103                                 struct flow_stats *new_stats;
 104
 105                                 new_stats =
 106                                         kmem_cache_alloc_node(flow_stats_cache,
 107                                                               GFP_THISNODE |
 108                                                               __GFP_NOMEMALLOC,
 109                                                               node);
 110                                 if (likely(new_stats)) {
 111                                         new_stats->used = jiffies;
 112                                         new_stats->packet_count = 1;
 113                                         new_stats->byte_count = skb->len;
 114                                         new_stats->tcp_flags = tcp_flags;
 115                                         spin_lock_init(&new_stats->lock);
 116
 117                                         rcu_assign_pointer(flow->stats[node],
 118                                                            new_stats);
 119                                         goto unlock;
 120                                 }
 121                         }
 122                         flow->stats_last_writer = node;
 123                 }
 124         }
 125
 126         stats->used = jiffies;
 127         stats->packet_count++;
 128         stats->byte_count += skb->len;
 129         stats->tcp_flags |= tcp_flags;
 130 unlock:
 131         spin_unlock(&stats->lock);
 132 }
 133
 134 void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,
 135                         unsigned long *used, __be16 *tcp_flags)
 136 {
 137         int node;
 138
 139         *used = 0;
 140         *tcp_flags = 0;
 141         memset(ovs_stats, 0, sizeof(*ovs_stats));
 142
 143         for_each_node(node) {
 144                 struct flow_stats *stats = rcu_dereference(flow->stats[node]);
 145
 146                 if (stats) {
 147                         /* Local CPU may write on non-local stats, so we must
 148                          * block bottom-halves here.
 149                          */
 150                         spin_lock_bh(&stats->lock);
 151                         if (time_after(stats->used, *used))
 152                                 *used = stats->used;
 153                         *tcp_flags |= stats->tcp_flags;
 154                         ovs_stats->n_packets += stats->packet_count;
 155                         ovs_stats->n_bytes += stats->byte_count;
 156                         spin_unlock_bh(&stats->lock);
 157                 }
 158         }
 159 }
 160
 161 void ovs_flow_stats_clear(struct sw_flow *flow)
 162 {
 163         int node;
 164
 165         for_each_node(node) {
 166                 struct flow_stats *stats = rcu_dereference(flow->stats[node]);
 167
 168                 if (stats) {
 169                         spin_lock_bh(&stats->lock);
 170                         stats->used = 0;
 171                         stats->packet_count = 0;
 172                         stats->byte_count = 0;
 173                         stats->tcp_flags = 0;
 174                         spin_unlock_bh(&stats->lock);
 175                 }
 176         }
 177 }
 178
 179 static int check_header(struct sk_buff *skb, int len)
 180 {
 181         if (unlikely(skb->len < len))
 182                 return -EINVAL;
 183         if (unlikely(!pskb_may_pull(skb, len)))
 184                 return -ENOMEM;
 185         return 0;
 186 }
 187
 188 static bool arphdr_ok(struct sk_buff *skb)
 189 {
 190         return pskb_may_pull(skb, skb_network_offset(skb) +
 191                                   sizeof(struct arp_eth_header));
 192 }
 193
 194 static int check_iphdr(struct sk_buff *skb)
 195 {
 196         unsigned int nh_ofs = skb_network_offset(skb);
 197         unsigned int ip_len;
 198         int err;
 199
 200         err = check_header(skb, nh_ofs + sizeof(struct iphdr));
 201         if (unlikely(err))
 202                 return err;
 203
 204         ip_len = ip_hdrlen(skb);
 205         if (unlikely(ip_len < sizeof(struct iphdr) ||
 206                      skb->len < nh_ofs + ip_len))
 207                 return -EINVAL;
 208
 209         skb_set_transport_header(skb, nh_ofs + ip_len);
 210         return 0;
 211 }
 212
 213 static bool tcphdr_ok(struct sk_buff *skb)
 214 {
 215         int th_ofs = skb_transport_offset(skb);
 216         int tcp_len;
 217
 218         if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
 219                 return false;
 220
 221         tcp_len = tcp_hdrlen(skb);
 222         if (unlikely(tcp_len < sizeof(struct tcphdr) ||
 223                      skb->len < th_ofs + tcp_len))
 224                 return false;
 225
 226         return true;
 227 }
 228
 229 static bool udphdr_ok(struct sk_buff *skb)
 230 {
 231         return pskb_may_pull(skb, skb_transport_offset(skb) +
 232                                   sizeof(struct udphdr));
 233 }
 234
 235 static bool sctphdr_ok(struct sk_buff *skb)
 236 {
 237         return pskb_may_pull(skb, skb_transport_offset(skb) +
 238                                   sizeof(struct sctphdr));
 239 }
 240
 241 static bool icmphdr_ok(struct sk_buff *skb)
 242 {
 243         return pskb_may_pull(skb, skb_transport_offset(skb) +
 244                                   sizeof(struct icmphdr));
 245 }
 246
 247 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
 248 {
 249         unsigned int nh_ofs = skb_network_offset(skb);
 250         unsigned int nh_len;
 251         int payload_ofs;
 252         struct ipv6hdr *nh;
 253         uint8_t nexthdr;
 254         __be16 frag_off;
 255         int err;
 256
 257         err = check_header(skb, nh_ofs + sizeof(*nh));
 258         if (unlikely(err))
 259                 return err;
 260
 261         nh = ipv6_hdr(skb);
 262         nexthdr = nh->nexthdr;
 263         payload_ofs = (u8 *)(nh + 1) - skb->data;
 264
 265         key->ip.proto = NEXTHDR_NONE;
 266         key->ip.tos = ipv6_get_dsfield(nh);
 267         key->ip.ttl = nh->hop_limit;
 268         key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 269         key->ipv6.addr.src = nh->saddr;
 270         key->ipv6.addr.dst = nh->daddr;
 271
 272         payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
 273         if (unlikely(payload_ofs < 0))
 274                 return -EINVAL;
 275
 276         if (frag_off) {
 277                 if (frag_off & htons(~0x7))
 278                         key->ip.frag = OVS_FRAG_TYPE_LATER;
 279                 else
 280                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 281         }
 282
 283         nh_len = payload_ofs - nh_ofs;
 284         skb_set_transport_header(skb, nh_ofs + nh_len);
 285         key->ip.proto = nexthdr;
 286         return nh_len;
 287 }
 288
 289 static bool icmp6hdr_ok(struct sk_buff *skb)
 290 {
 291         return pskb_may_pull(skb, skb_transport_offset(skb) +
 292                                   sizeof(struct icmp6hdr));
 293 }
 294
 295 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 296 {
 297         struct qtag_prefix {
 298                 __be16 eth_type; /* ETH_P_8021Q */
 299                 __be16 tci;
 300         };
 301         struct qtag_prefix *qp;
 302
 303         if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
 304                 return 0;
 305
 306         if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
 307                                          sizeof(__be16))))
 308                 return -ENOMEM;
 309
 310         qp = (struct qtag_prefix *) skb->data;
 311         key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
 312         __skb_pull(skb, sizeof(struct qtag_prefix));
 313
 314         return 0;
 315 }
 316
 317 static __be16 parse_ethertype(struct sk_buff *skb)
 318 {
 319         struct llc_snap_hdr {
 320                 u8  dsap;  /* Always 0xAA */
 321                 u8  ssap;  /* Always 0xAA */
 322                 u8  ctrl;
 323                 u8  oui[3];
 324                 __be16 ethertype;
 325         };
 326         struct llc_snap_hdr *llc;
 327         __be16 proto;
 328
 329         proto = *(__be16 *) skb->data;
 330         __skb_pull(skb, sizeof(__be16));
 331
 332         if (ntohs(proto) >= ETH_P_802_3_MIN)
 333                 return proto;
 334
 335         if (skb->len < sizeof(struct llc_snap_hdr))
 336                 return htons(ETH_P_802_2);
 337
 338         if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
 339                 return htons(0);
 340
 341         llc = (struct llc_snap_hdr *) skb->data;
 342         if (llc->dsap != LLC_SAP_SNAP ||
 343             llc->ssap != LLC_SAP_SNAP ||
 344             (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
 345                 return htons(ETH_P_802_2);
 346
 347         __skb_pull(skb, sizeof(struct llc_snap_hdr));
 348
 349         if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN)
 350                 return llc->ethertype;
 351
 352         return htons(ETH_P_802_2);
 353 }
 354
 355 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
 356                         int nh_len)
 357 {
 358         struct icmp6hdr *icmp = icmp6_hdr(skb);
 359
 360         /* The ICMPv6 type and code fields use the 16-bit transport port
 361          * fields, so we need to store them in 16-bit network byte order.
 362          */
 363         key->ipv6.tp.src = htons(icmp->icmp6_type);
 364         key->ipv6.tp.dst = htons(icmp->icmp6_code);
 365
 366         if (icmp->icmp6_code == 0 &&
 367             (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
 368              icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
 369                 int icmp_len = skb->len - skb_transport_offset(skb);
 370                 struct nd_msg *nd;
 371                 int offset;
 372
 373                 /* In order to process neighbor discovery options, we need the
 374                  * entire packet.
 375                  */
 376                 if (unlikely(icmp_len < sizeof(*nd)))
 377                         return 0;
 378
 379                 if (unlikely(skb_linearize(skb)))
 380                         return -ENOMEM;
 381
 382                 nd = (struct nd_msg *)skb_transport_header(skb);
 383                 key->ipv6.nd.target = nd->target;
 384
 385                 icmp_len -= sizeof(*nd);
 386                 offset = 0;
 387                 while (icmp_len >= 8) {
 388                         struct nd_opt_hdr *nd_opt =
 389                                  (struct nd_opt_hdr *)(nd->opt + offset);
 390                         int opt_len = nd_opt->nd_opt_len * 8;
 391
 392                         if (unlikely(!opt_len || opt_len > icmp_len))
 393                                 return 0;
 394
 395                         /* Store the link layer address if the appropriate
 396                          * option is provided.  It is considered an error if
 397                          * the same link layer option is specified twice.
 398                          */
 399                         if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
 400                             && opt_len == 8) {
 401                                 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
 402                                         goto invalid;
 403                                 memcpy(key->ipv6.nd.sll,
 404                                     &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
 405                         } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
 406                                    && opt_len == 8) {
 407                                 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
 408                                         goto invalid;
 409                                 memcpy(key->ipv6.nd.tll,
 410                                     &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
 411                         }
 412
 413                         icmp_len -= opt_len;
 414                         offset += opt_len;
 415                 }
 416         }
 417
 418         return 0;
 419
 420 invalid:
 421         memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
 422         memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
 423         memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
 424
 425         return 0;
 426 }
 427
 428 /**
 429  * ovs_flow_extract - extracts a flow key from an Ethernet frame.
 430  * @skb: sk_buff that contains the frame, with skb->data pointing to the
 431  * Ethernet header
 432  * @in_port: port number on which @skb was received.
 433  * @key: output flow key
 434  *
 435  * The caller must ensure that skb->len >= ETH_HLEN.
 436  *
 437  * Returns 0 if successful, otherwise a negative errno value.
 438  *
 439  * Initializes @skb header pointers as follows:
 440  *
 441  *    - skb->mac_header: the Ethernet header.
 442  *
 443  *    - skb->network_header: just past the Ethernet header, or just past the
 444  *      VLAN header, to the first byte of the Ethernet payload.
 445  *
 446  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
 447  *      on output, then just past the IP header, if one is present and
 448  *      of a correct length, otherwise the same as skb->network_header.
 449  *      For other key->eth.type values it is left untouched.
 450  */
 451 int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
 452 {
 453         int error;
 454         struct ethhdr *eth;
 455
 456         memset(key, 0, sizeof(*key));
 457
 458         key->phy.priority = skb->priority;
 459         if (OVS_CB(skb)->tun_key)
 460                 memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key));
 461         key->phy.in_port = in_port;
 462         key->phy.skb_mark = skb->mark;
 463
 464         skb_reset_mac_header(skb);
 465
 466         /* Link layer.  We are guaranteed to have at least the 14 byte Ethernet
 467          * header in the linear data area.
 468          */
 469         eth = eth_hdr(skb);
 470         memcpy(key->eth.src, eth->h_source, ETH_ALEN);
 471         memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);
 472
 473         __skb_pull(skb, 2 * ETH_ALEN);
 474         /* We are going to push all headers that we pull, so no need to
 475          * update skb->csum here. */
 476
 477         if (vlan_tx_tag_present(skb))
 478                 key->eth.tci = htons(vlan_get_tci(skb));
 479         else if (eth->h_proto == htons(ETH_P_8021Q))
 480                 if (unlikely(parse_vlan(skb, key)))
 481                         return -ENOMEM;
 482
 483         key->eth.type = parse_ethertype(skb);
 484         if (unlikely(key->eth.type == htons(0)))
 485                 return -ENOMEM;
 486
 487         skb_reset_network_header(skb);
 488         __skb_push(skb, skb->data - skb_mac_header(skb));
 489
 490         /* Network layer. */
 491         if (key->eth.type == htons(ETH_P_IP)) {
 492                 struct iphdr *nh;
 493                 __be16 offset;
 494
 495                 error = check_iphdr(skb);
 496                 if (unlikely(error)) {
 497                         if (error == -EINVAL) {
 498                                 skb->transport_header = skb->network_header;
 499                                 error = 0;
 500                         }
 501                         return error;
 502                 }
 503
 504                 nh = ip_hdr(skb);
 505                 key->ipv4.addr.src = nh->saddr;
 506                 key->ipv4.addr.dst = nh->daddr;
 507
 508                 key->ip.proto = nh->protocol;
 509                 key->ip.tos = nh->tos;
 510                 key->ip.ttl = nh->ttl;
 511
 512                 offset = nh->frag_off & htons(IP_OFFSET);
 513                 if (offset) {
 514                         key->ip.frag = OVS_FRAG_TYPE_LATER;
 515                         return 0;
 516                 }
 517                 if (nh->frag_off & htons(IP_MF) ||
 518                          skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 519                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 520
 521                 /* Transport layer. */
 522                 if (key->ip.proto == IPPROTO_TCP) {
 523                         if (tcphdr_ok(skb)) {
 524                                 struct tcphdr *tcp = tcp_hdr(skb);
 525                                 key->ipv4.tp.src = tcp->source;
 526                                 key->ipv4.tp.dst = tcp->dest;
 527                                 key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp);
 528                         }
 529                 } else if (key->ip.proto == IPPROTO_UDP) {
 530                         if (udphdr_ok(skb)) {
 531                                 struct udphdr *udp = udp_hdr(skb);
 532                                 key->ipv4.tp.src = udp->source;
 533                                 key->ipv4.tp.dst = udp->dest;
 534                         }
 535                 } else if (key->ip.proto == IPPROTO_SCTP) {
 536                         if (sctphdr_ok(skb)) {
 537                                 struct sctphdr *sctp = sctp_hdr(skb);
 538                                 key->ipv4.tp.src = sctp->source;
 539                                 key->ipv4.tp.dst = sctp->dest;
 540                         }
 541                 } else if (key->ip.proto == IPPROTO_ICMP) {
 542                         if (icmphdr_ok(skb)) {
 543                                 struct icmphdr *icmp = icmp_hdr(skb);
 544                                 /* The ICMP type and code fields use the 16-bit
 545                                  * transport port fields, so we need to store
 546                                  * them in 16-bit network byte order. */
 547                                 key->ipv4.tp.src = htons(icmp->type);
 548                                 key->ipv4.tp.dst = htons(icmp->code);
 549                         }
 550                 }
 551
 552         } else if ((key->eth.type == htons(ETH_P_ARP) ||
 553                    key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) {
 554                 struct arp_eth_header *arp;
 555
 556                 arp = (struct arp_eth_header *)skb_network_header(skb);
 557
 558                 if (arp->ar_hrd == htons(ARPHRD_ETHER)
 559                                 && arp->ar_pro == htons(ETH_P_IP)
 560                                 && arp->ar_hln == ETH_ALEN
 561                                 && arp->ar_pln == 4) {
 562
 563                         /* We only match on the lower 8 bits of the opcode. */
 564                         if (ntohs(arp->ar_op) <= 0xff)
 565                                 key->ip.proto = ntohs(arp->ar_op);
 566                         memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
 567                         memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
 568                         memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN);
 569                         memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN);
 570                 }
 571         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 572                 int nh_len;             /* IPv6 Header + Extensions */
 573
 574                 nh_len = parse_ipv6hdr(skb, key);
 575                 if (unlikely(nh_len < 0)) {
 576                         if (nh_len == -EINVAL) {
 577                                 skb->transport_header = skb->network_header;
 578                                 error = 0;
 579                         } else {
 580                                 error = nh_len;
 581                         }
 582                         return error;
 583                 }
 584
 585                 if (key->ip.frag == OVS_FRAG_TYPE_LATER)
 586                         return 0;
 587                 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 588                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 589
 590                 /* Transport layer. */
 591                 if (key->ip.proto == NEXTHDR_TCP) {
 592                         if (tcphdr_ok(skb)) {
 593                                 struct tcphdr *tcp = tcp_hdr(skb);
 594                                 key->ipv6.tp.src = tcp->source;
 595                                 key->ipv6.tp.dst = tcp->dest;
 596                                 key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp);
 597                         }
 598                 } else if (key->ip.proto == NEXTHDR_UDP) {
 599                         if (udphdr_ok(skb)) {
 600                                 struct udphdr *udp = udp_hdr(skb);
 601                                 key->ipv6.tp.src = udp->source;
 602                                 key->ipv6.tp.dst = udp->dest;
 603                         }
 604                 } else if (key->ip.proto == NEXTHDR_SCTP) {
 605                         if (sctphdr_ok(skb)) {
 606                                 struct sctphdr *sctp = sctp_hdr(skb);
 607                                 key->ipv6.tp.src = sctp->source;
 608                                 key->ipv6.tp.dst = sctp->dest;
 609                         }
 610                 } else if (key->ip.proto == NEXTHDR_ICMP) {
 611                         if (icmp6hdr_ok(skb)) {
 612                                 error = parse_icmpv6(skb, key, nh_len);
 613                                 if (error)
 614                                         return error;
 615                         }
 616                 }
 617         }
 618
 619         return 0;
 620 }