datapath/flow.c

   1 /*
   2  * Copyright (c) 2007-2014 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 (likely(flow->key.ip.proto == IPPROTO_TCP)) {
  74                 if (likely(flow->key.eth.type == htons(ETH_P_IP)))
  75                         tcp_flags = flow->key.ipv4.tp.flags;
  76                 else if (likely(flow->key.eth.type == htons(ETH_P_IPV6)))
  77                         tcp_flags = flow->key.ipv6.tp.flags;
  78         }
  79         /* Check if already have node-specific stats. */
  80         if (likely(stats)) {
  81                 spin_lock(&stats->lock);
  82                 /* Mark if we write on the pre-allocated stats. */
  83                 if (node == 0 && unlikely(flow->stats_last_writer != node))
  84                         flow->stats_last_writer = node;
  85         } else {
  86                 stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
  87                 spin_lock(&stats->lock);
  88
  89                 /* If the current NUMA-node is the only writer on the
  90                  * pre-allocated stats keep using them.
  91                  */
  92                 if (unlikely(flow->stats_last_writer != node)) {
  93                         /* A previous locker may have already allocated the
  94                          * stats, so we need to check again.  If node-specific
  95                          * stats were already allocated, we update the pre-
  96                          * allocated stats as we have already locked them.
  97                          */
  98                         if (likely(flow->stats_last_writer != NUMA_NO_NODE)
  99                             && likely(!rcu_dereference(flow->stats[node]))) {
 100                                 /* Try to allocate node-specific stats. */
 101                                 struct flow_stats *new_stats;
 102
 103                                 new_stats =
 104                                         kmem_cache_alloc_node(flow_stats_cache,
 105                                                               GFP_THISNODE |
 106                                                               __GFP_NOMEMALLOC,
 107                                                               node);
 108                                 if (likely(new_stats)) {
 109                                         new_stats->used = jiffies;
 110                                         new_stats->packet_count = 1;
 111                                         new_stats->byte_count = skb->len;
 112                                         new_stats->tcp_flags = tcp_flags;
 113                                         spin_lock_init(&new_stats->lock);
 114
 115                                         rcu_assign_pointer(flow->stats[node],
 116                                                            new_stats);
 117                                         goto unlock;
 118                                 }
 119                         }
 120                         flow->stats_last_writer = node;
 121                 }
 122         }
 123
 124         stats->used = jiffies;
 125         stats->packet_count++;
 126         stats->byte_count += skb->len;
 127         stats->tcp_flags |= tcp_flags;
 128 unlock:
 129         spin_unlock(&stats->lock);
 130 }
 131
 132 void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,
 133                         unsigned long *used, __be16 *tcp_flags)
 134 {
 135         int node;
 136
 137         *used = 0;
 138         *tcp_flags = 0;
 139         memset(ovs_stats, 0, sizeof(*ovs_stats));
 140
 141         for_each_node(node) {
 142                 struct flow_stats *stats = rcu_dereference(flow->stats[node]);
 143
 144                 if (stats) {
 145                         /* Local CPU may write on non-local stats, so we must
 146                          * block bottom-halves here.
 147                          */
 148                         spin_lock_bh(&stats->lock);
 149                         if (!*used || time_after(stats->used, *used))
 150                                 *used = stats->used;
 151                         *tcp_flags |= stats->tcp_flags;
 152                         ovs_stats->n_packets += stats->packet_count;
 153                         ovs_stats->n_bytes += stats->byte_count;
 154                         spin_unlock_bh(&stats->lock);
 155                 }
 156         }
 157 }
 158
 159 void ovs_flow_stats_clear(struct sw_flow *flow)
 160 {
 161         int node;
 162
 163         for_each_node(node) {
 164                 struct flow_stats *stats = rcu_dereference(flow->stats[node]);
 165
 166                 if (stats) {
 167                         spin_lock_bh(&stats->lock);
 168                         stats->used = 0;
 169                         stats->packet_count = 0;
 170                         stats->byte_count = 0;
 171                         stats->tcp_flags = 0;
 172                         spin_unlock_bh(&stats->lock);
 173                 }
 174         }
 175 }
 176
 177 static int check_header(struct sk_buff *skb, int len)
 178 {
 179         if (unlikely(skb->len < len))
 180                 return -EINVAL;
 181         if (unlikely(!pskb_may_pull(skb, len)))
 182                 return -ENOMEM;
 183         return 0;
 184 }
 185
 186 static bool arphdr_ok(struct sk_buff *skb)
 187 {
 188         return pskb_may_pull(skb, skb_network_offset(skb) +
 189                                   sizeof(struct arp_eth_header));
 190 }
 191
 192 static int check_iphdr(struct sk_buff *skb)
 193 {
 194         unsigned int nh_ofs = skb_network_offset(skb);
 195         unsigned int ip_len;
 196         int err;
 197
 198         err = check_header(skb, nh_ofs + sizeof(struct iphdr));
 199         if (unlikely(err))
 200                 return err;
 201
 202         ip_len = ip_hdrlen(skb);
 203         if (unlikely(ip_len < sizeof(struct iphdr) ||
 204                      skb->len < nh_ofs + ip_len))
 205                 return -EINVAL;
 206
 207         skb_set_transport_header(skb, nh_ofs + ip_len);
 208         return 0;
 209 }
 210
 211 static bool tcphdr_ok(struct sk_buff *skb)
 212 {
 213         int th_ofs = skb_transport_offset(skb);
 214         int tcp_len;
 215
 216         if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
 217                 return false;
 218
 219         tcp_len = tcp_hdrlen(skb);
 220         if (unlikely(tcp_len < sizeof(struct tcphdr) ||
 221                      skb->len < th_ofs + tcp_len))
 222                 return false;
 223
 224         return true;
 225 }
 226
 227 static bool udphdr_ok(struct sk_buff *skb)
 228 {
 229         return pskb_may_pull(skb, skb_transport_offset(skb) +
 230                                   sizeof(struct udphdr));
 231 }
 232
 233 static bool sctphdr_ok(struct sk_buff *skb)
 234 {
 235         return pskb_may_pull(skb, skb_transport_offset(skb) +
 236                                   sizeof(struct sctphdr));
 237 }
 238
 239 static bool icmphdr_ok(struct sk_buff *skb)
 240 {
 241         return pskb_may_pull(skb, skb_transport_offset(skb) +
 242                                   sizeof(struct icmphdr));
 243 }
 244
 245 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
 246 {
 247         unsigned int nh_ofs = skb_network_offset(skb);
 248         unsigned int nh_len;
 249         int payload_ofs;
 250         struct ipv6hdr *nh;
 251         uint8_t nexthdr;
 252         __be16 frag_off;
 253         int err;
 254
 255         err = check_header(skb, nh_ofs + sizeof(*nh));
 256         if (unlikely(err))
 257                 return err;
 258
 259         nh = ipv6_hdr(skb);
 260         nexthdr = nh->nexthdr;
 261         payload_ofs = (u8 *)(nh + 1) - skb->data;
 262
 263         key->ip.proto = NEXTHDR_NONE;
 264         key->ip.tos = ipv6_get_dsfield(nh);
 265         key->ip.ttl = nh->hop_limit;
 266         key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 267         key->ipv6.addr.src = nh->saddr;
 268         key->ipv6.addr.dst = nh->daddr;
 269
 270         payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
 271         if (unlikely(payload_ofs < 0))
 272                 return -EINVAL;
 273
 274         if (frag_off) {
 275                 if (frag_off & htons(~0x7))
 276                         key->ip.frag = OVS_FRAG_TYPE_LATER;
 277                 else
 278                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 279         }
 280
 281         nh_len = payload_ofs - nh_ofs;
 282         skb_set_transport_header(skb, nh_ofs + nh_len);
 283         key->ip.proto = nexthdr;
 284         return nh_len;
 285 }
 286
 287 static bool icmp6hdr_ok(struct sk_buff *skb)
 288 {
 289         return pskb_may_pull(skb, skb_transport_offset(skb) +
 290                                   sizeof(struct icmp6hdr));
 291 }
 292
 293 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 294 {
 295         struct qtag_prefix {
 296                 __be16 eth_type; /* ETH_P_8021Q */
 297                 __be16 tci;
 298         };
 299         struct qtag_prefix *qp;
 300
 301         if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
 302                 return 0;
 303
 304         if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
 305                                          sizeof(__be16))))
 306                 return -ENOMEM;
 307
 308         qp = (struct qtag_prefix *) skb->data;
 309         key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
 310         __skb_pull(skb, sizeof(struct qtag_prefix));
 311
 312         return 0;
 313 }
 314
 315 static __be16 parse_ethertype(struct sk_buff *skb)
 316 {
 317         struct llc_snap_hdr {
 318                 u8  dsap;  /* Always 0xAA */
 319                 u8  ssap;  /* Always 0xAA */
 320                 u8  ctrl;
 321                 u8  oui[3];
 322                 __be16 ethertype;
 323         };
 324         struct llc_snap_hdr *llc;
 325         __be16 proto;
 326
 327         proto = *(__be16 *) skb->data;
 328         __skb_pull(skb, sizeof(__be16));
 329
 330         if (ntohs(proto) >= ETH_P_802_3_MIN)
 331                 return proto;
 332
 333         if (skb->len < sizeof(struct llc_snap_hdr))
 334                 return htons(ETH_P_802_2);
 335
 336         if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
 337                 return htons(0);
 338
 339         llc = (struct llc_snap_hdr *) skb->data;
 340         if (llc->dsap != LLC_SAP_SNAP ||
 341             llc->ssap != LLC_SAP_SNAP ||
 342             (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
 343                 return htons(ETH_P_802_2);
 344
 345         __skb_pull(skb, sizeof(struct llc_snap_hdr));
 346
 347         if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN)
 348                 return llc->ethertype;
 349
 350         return htons(ETH_P_802_2);
 351 }
 352
 353 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
 354                         int nh_len)
 355 {
 356         struct icmp6hdr *icmp = icmp6_hdr(skb);
 357
 358         /* The ICMPv6 type and code fields use the 16-bit transport port
 359          * fields, so we need to store them in 16-bit network byte order.
 360          */
 361         key->ipv6.tp.src = htons(icmp->icmp6_type);
 362         key->ipv6.tp.dst = htons(icmp->icmp6_code);
 363
 364         if (icmp->icmp6_code == 0 &&
 365             (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
 366              icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
 367                 int icmp_len = skb->len - skb_transport_offset(skb);
 368                 struct nd_msg *nd;
 369                 int offset;
 370
 371                 /* In order to process neighbor discovery options, we need the
 372                  * entire packet.
 373                  */
 374                 if (unlikely(icmp_len < sizeof(*nd)))
 375                         return 0;
 376
 377                 if (unlikely(skb_linearize(skb)))
 378                         return -ENOMEM;
 379
 380                 nd = (struct nd_msg *)skb_transport_header(skb);
 381                 key->ipv6.nd.target = nd->target;
 382
 383                 icmp_len -= sizeof(*nd);
 384                 offset = 0;
 385                 while (icmp_len >= 8) {
 386                         struct nd_opt_hdr *nd_opt =
 387                                  (struct nd_opt_hdr *)(nd->opt + offset);
 388                         int opt_len = nd_opt->nd_opt_len * 8;
 389
 390                         if (unlikely(!opt_len || opt_len > icmp_len))
 391                                 return 0;
 392
 393                         /* Store the link layer address if the appropriate
 394                          * option is provided.  It is considered an error if
 395                          * the same link layer option is specified twice.
 396                          */
 397                         if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
 398                             && opt_len == 8) {
 399                                 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
 400                                         goto invalid;
 401                                 ether_addr_copy(key->ipv6.nd.sll,
 402                                     &nd->opt[offset+sizeof(*nd_opt)]);
 403                         } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
 404                                    && opt_len == 8) {
 405                                 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
 406                                         goto invalid;
 407                                 ether_addr_copy(key->ipv6.nd.tll,
 408                                     &nd->opt[offset+sizeof(*nd_opt)]);
 409                         }
 410
 411                         icmp_len -= opt_len;
 412                         offset += opt_len;
 413                 }
 414         }
 415
 416         return 0;
 417
 418 invalid:
 419         memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
 420         memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
 421         memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
 422
 423         return 0;
 424 }
 425
 426 /**
 427  * ovs_flow_extract - extracts a flow key from an Ethernet frame.
 428  * @skb: sk_buff that contains the frame, with skb->data pointing to the
 429  * Ethernet header
 430  * @in_port: port number on which @skb was received.
 431  * @key: output flow key
 432  *
 433  * The caller must ensure that skb->len >= ETH_HLEN.
 434  *
 435  * Returns 0 if successful, otherwise a negative errno value.
 436  *
 437  * Initializes @skb header pointers as follows:
 438  *
 439  *    - skb->mac_header: the Ethernet header.
 440  *
 441  *    - skb->network_header: just past the Ethernet header, or just past the
 442  *      VLAN header, to the first byte of the Ethernet payload.
 443  *
 444  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
 445  *      on output, then just past the IP header, if one is present and
 446  *      of a correct length, otherwise the same as skb->network_header.
 447  *      For other key->eth.type values it is left untouched.
 448  */
 449 int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
 450 {
 451         int error;
 452         struct ethhdr *eth;
 453
 454         memset(key, 0, sizeof(*key));
 455
 456         key->phy.priority = skb->priority;
 457         if (OVS_CB(skb)->tun_key)
 458                 memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key));
 459         key->phy.in_port = in_port;
 460         key->phy.skb_mark = skb->mark;
 461
 462         skb_reset_mac_header(skb);
 463
 464         /* Link layer.  We are guaranteed to have at least the 14 byte Ethernet
 465          * header in the linear data area.
 466          */
 467         eth = eth_hdr(skb);
 468         ether_addr_copy(key->eth.src, eth->h_source);
 469         ether_addr_copy(key->eth.dst, eth->h_dest);
 470
 471         __skb_pull(skb, 2 * ETH_ALEN);
 472         /* We are going to push all headers that we pull, so no need to
 473          * update skb->csum here. */
 474
 475         if (vlan_tx_tag_present(skb))
 476                 key->eth.tci = htons(vlan_get_tci(skb));
 477         else if (eth->h_proto == htons(ETH_P_8021Q))
 478                 if (unlikely(parse_vlan(skb, key)))
 479                         return -ENOMEM;
 480
 481         key->eth.type = parse_ethertype(skb);
 482         if (unlikely(key->eth.type == htons(0)))
 483                 return -ENOMEM;
 484
 485         skb_reset_network_header(skb);
 486         __skb_push(skb, skb->data - skb_mac_header(skb));
 487
 488         /* Network layer. */
 489         if (key->eth.type == htons(ETH_P_IP)) {
 490                 struct iphdr *nh;
 491                 __be16 offset;
 492
 493                 error = check_iphdr(skb);
 494                 if (unlikely(error)) {
 495                         if (error == -EINVAL) {
 496                                 skb->transport_header = skb->network_header;
 497                                 error = 0;
 498                         }
 499                         return error;
 500                 }
 501
 502                 nh = ip_hdr(skb);
 503                 key->ipv4.addr.src = nh->saddr;
 504                 key->ipv4.addr.dst = nh->daddr;
 505
 506                 key->ip.proto = nh->protocol;
 507                 key->ip.tos = nh->tos;
 508                 key->ip.ttl = nh->ttl;
 509
 510                 offset = nh->frag_off & htons(IP_OFFSET);
 511                 if (offset) {
 512                         key->ip.frag = OVS_FRAG_TYPE_LATER;
 513                         return 0;
 514                 }
 515                 if (nh->frag_off & htons(IP_MF) ||
 516                          skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 517                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 518
 519                 /* Transport layer. */
 520                 if (key->ip.proto == IPPROTO_TCP) {
 521                         if (tcphdr_ok(skb)) {
 522                                 struct tcphdr *tcp = tcp_hdr(skb);
 523                                 key->ipv4.tp.src = tcp->source;
 524                                 key->ipv4.tp.dst = tcp->dest;
 525                                 key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp);
 526                         }
 527                 } else if (key->ip.proto == IPPROTO_UDP) {
 528                         if (udphdr_ok(skb)) {
 529                                 struct udphdr *udp = udp_hdr(skb);
 530                                 key->ipv4.tp.src = udp->source;
 531                                 key->ipv4.tp.dst = udp->dest;
 532                         }
 533                 } else if (key->ip.proto == IPPROTO_SCTP) {
 534                         if (sctphdr_ok(skb)) {
 535                                 struct sctphdr *sctp = sctp_hdr(skb);
 536                                 key->ipv4.tp.src = sctp->source;
 537                                 key->ipv4.tp.dst = sctp->dest;
 538                         }
 539                 } else if (key->ip.proto == IPPROTO_ICMP) {
 540                         if (icmphdr_ok(skb)) {
 541                                 struct icmphdr *icmp = icmp_hdr(skb);
 542                                 /* The ICMP type and code fields use the 16-bit
 543                                  * transport port fields, so we need to store
 544                                  * them in 16-bit network byte order. */
 545                                 key->ipv4.tp.src = htons(icmp->type);
 546                                 key->ipv4.tp.dst = htons(icmp->code);
 547                         }
 548                 }
 549
 550         } else if ((key->eth.type == htons(ETH_P_ARP) ||
 551                    key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) {
 552                 struct arp_eth_header *arp;
 553
 554                 arp = (struct arp_eth_header *)skb_network_header(skb);
 555
 556                 if (arp->ar_hrd == htons(ARPHRD_ETHER)
 557                                 && arp->ar_pro == htons(ETH_P_IP)
 558                                 && arp->ar_hln == ETH_ALEN
 559                                 && arp->ar_pln == 4) {
 560
 561                         /* We only match on the lower 8 bits of the opcode. */
 562                         if (ntohs(arp->ar_op) <= 0xff)
 563                                 key->ip.proto = ntohs(arp->ar_op);
 564                         memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
 565                         memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
 566                         ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
 567                         ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
 568                 }
 569         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 570                 int nh_len;             /* IPv6 Header + Extensions */
 571
 572                 nh_len = parse_ipv6hdr(skb, key);
 573                 if (unlikely(nh_len < 0)) {
 574                         if (nh_len == -EINVAL) {
 575                                 skb->transport_header = skb->network_header;
 576                                 error = 0;
 577                         } else {
 578                                 error = nh_len;
 579                         }
 580                         return error;
 581                 }
 582
 583                 if (key->ip.frag == OVS_FRAG_TYPE_LATER)
 584                         return 0;
 585                 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 586                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 587
 588                 /* Transport layer. */
 589                 if (key->ip.proto == NEXTHDR_TCP) {
 590                         if (tcphdr_ok(skb)) {
 591                                 struct tcphdr *tcp = tcp_hdr(skb);
 592                                 key->ipv6.tp.src = tcp->source;
 593                                 key->ipv6.tp.dst = tcp->dest;
 594                                 key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp);
 595                         }
 596                 } else if (key->ip.proto == NEXTHDR_UDP) {
 597                         if (udphdr_ok(skb)) {
 598                                 struct udphdr *udp = udp_hdr(skb);
 599                                 key->ipv6.tp.src = udp->source;
 600                                 key->ipv6.tp.dst = udp->dest;
 601                         }
 602                 } else if (key->ip.proto == NEXTHDR_SCTP) {
 603                         if (sctphdr_ok(skb)) {
 604                                 struct sctphdr *sctp = sctp_hdr(skb);
 605                                 key->ipv6.tp.src = sctp->source;
 606                                 key->ipv6.tp.dst = sctp->dest;
 607                         }
 608                 } else if (key->ip.proto == NEXTHDR_ICMP) {
 609                         if (icmp6hdr_ok(skb)) {
 610                                 error = parse_icmpv6(skb, key, nh_len);
 611                                 if (error)
 612                                         return error;
 613                         }
 614                 }
 615         }
 616
 617         return 0;
 618 }