datapath/flow.c

   1 /*
   2  * Distributed under the terms of the GNU GPL version 2.
   3  * Copyright (c) 2007, 2008, 2009, 2010, 2011 Nicira Networks.
   4  *
   5  * Significant portions of this file may be copied from parts of the Linux
   6  * kernel, by Linus Torvalds and others.
   7  */
   8
   9 #include "flow.h"
  10 #include "datapath.h"
  11 #include <asm/uaccess.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/if_ether.h>
  15 #include <linux/if_vlan.h>
  16 #include <net/llc_pdu.h>
  17 #include <linux/kernel.h>
  18 #include <linux/jhash.h>
  19 #include <linux/jiffies.h>
  20 #include <linux/llc.h>
  21 #include <linux/module.h>
  22 #include <linux/in.h>
  23 #include <linux/rcupdate.h>
  24 #include <linux/if_arp.h>
  25 #include <linux/if_ether.h>
  26 #include <linux/ip.h>
  27 #include <linux/tcp.h>
  28 #include <linux/udp.h>
  29 #include <linux/icmp.h>
  30 #include <net/inet_ecn.h>
  31 #include <net/ip.h>
  32
  33 static struct kmem_cache *flow_cache;
  34 static unsigned int hash_seed __read_mostly;
  35
  36 static inline bool arphdr_ok(struct sk_buff *skb)
  37 {
  38         return skb->len >= skb_network_offset(skb) + sizeof(struct arp_eth_header);
  39 }
  40
  41 static inline int check_iphdr(struct sk_buff *skb)
  42 {
  43         unsigned int nh_ofs = skb_network_offset(skb);
  44         unsigned int ip_len;
  45
  46         if (skb->len < nh_ofs + sizeof(struct iphdr))
  47                 return -EINVAL;
  48
  49         ip_len = ip_hdrlen(skb);
  50         if (ip_len < sizeof(struct iphdr) || skb->len < nh_ofs + ip_len)
  51                 return -EINVAL;
  52
  53         /*
  54          * Pull enough header bytes to account for the IP header plus the
  55          * longest transport header that we parse, currently 20 bytes for TCP.
  56          */
  57         if (!pskb_may_pull(skb, min(nh_ofs + ip_len + 20, skb->len)))
  58                 return -ENOMEM;
  59
  60         skb_set_transport_header(skb, nh_ofs + ip_len);
  61         return 0;
  62 }
  63
  64 static inline bool tcphdr_ok(struct sk_buff *skb)
  65 {
  66         int th_ofs = skb_transport_offset(skb);
  67         if (skb->len >= th_ofs + sizeof(struct tcphdr)) {
  68                 int tcp_len = tcp_hdrlen(skb);
  69                 return (tcp_len >= sizeof(struct tcphdr)
  70                         && skb->len >= th_ofs + tcp_len);
  71         }
  72         return false;
  73 }
  74
  75 static inline bool udphdr_ok(struct sk_buff *skb)
  76 {
  77         return skb->len >= skb_transport_offset(skb) + sizeof(struct udphdr);
  78 }
  79
  80 static inline bool icmphdr_ok(struct sk_buff *skb)
  81 {
  82         return skb->len >= skb_transport_offset(skb) + sizeof(struct icmphdr);
  83 }
  84
  85 #define TCP_FLAGS_OFFSET 13
  86 #define TCP_FLAG_MASK 0x3f
  87
  88 void flow_used(struct sw_flow *flow, struct sk_buff *skb)
  89 {
  90         u8 tcp_flags = 0;
  91
  92         if (flow->key.dl_type == htons(ETH_P_IP) &&
  93             flow->key.nw_proto == IPPROTO_TCP) {
  94                 u8 *tcp = (u8 *)tcp_hdr(skb);
  95                 tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
  96         }
  97
  98         spin_lock_bh(&flow->lock);
  99         flow->used = jiffies;
 100         flow->packet_count++;
 101         flow->byte_count += skb->len;
 102         flow->tcp_flags |= tcp_flags;
 103         spin_unlock_bh(&flow->lock);
 104 }
 105
 106 struct sw_flow_actions *flow_actions_alloc(const struct nlattr *actions)
 107 {
 108         int actions_len = nla_len(actions);
 109         struct sw_flow_actions *sfa;
 110
 111         /* At least DP_MAX_PORTS actions are required to be able to flood a
 112          * packet to every port.  Factor of 2 allows for setting VLAN tags,
 113          * etc. */
 114         if (actions_len > 2 * DP_MAX_PORTS * nla_total_size(4))
 115                 return ERR_PTR(-EINVAL);
 116
 117         sfa = kmalloc(sizeof(*sfa) + actions_len, GFP_KERNEL);
 118         if (!sfa)
 119                 return ERR_PTR(-ENOMEM);
 120
 121         sfa->actions_len = actions_len;
 122         memcpy(sfa->actions, nla_data(actions), actions_len);
 123         return sfa;
 124 }
 125
 126 struct sw_flow *flow_alloc(void)
 127 {
 128         struct sw_flow *flow;
 129
 130         flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
 131         if (!flow)
 132                 return ERR_PTR(-ENOMEM);
 133
 134         spin_lock_init(&flow->lock);
 135         atomic_set(&flow->refcnt, 1);
 136         flow->dead = false;
 137
 138         return flow;
 139 }
 140
 141 void flow_free_tbl(struct tbl_node *node)
 142 {
 143         struct sw_flow *flow = flow_cast(node);
 144
 145         flow->dead = true;
 146         flow_put(flow);
 147 }
 148
 149 /* RCU callback used by flow_deferred_free. */
 150 static void rcu_free_flow_callback(struct rcu_head *rcu)
 151 {
 152         struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
 153
 154         flow->dead = true;
 155         flow_put(flow);
 156 }
 157
 158 /* Schedules 'flow' to be freed after the next RCU grace period.
 159  * The caller must hold rcu_read_lock for this to be sensible. */
 160 void flow_deferred_free(struct sw_flow *flow)
 161 {
 162         call_rcu(&flow->rcu, rcu_free_flow_callback);
 163 }
 164
 165 void flow_hold(struct sw_flow *flow)
 166 {
 167         atomic_inc(&flow->refcnt);
 168 }
 169
 170 void flow_put(struct sw_flow *flow)
 171 {
 172         if (unlikely(!flow))
 173                 return;
 174
 175         if (atomic_dec_and_test(&flow->refcnt)) {
 176                 kfree((struct sf_flow_acts __force *)flow->sf_acts);
 177                 kmem_cache_free(flow_cache, flow);
 178         }
 179 }
 180
 181 /* RCU callback used by flow_deferred_free_acts. */
 182 static void rcu_free_acts_callback(struct rcu_head *rcu)
 183 {
 184         struct sw_flow_actions *sf_acts = container_of(rcu,
 185                         struct sw_flow_actions, rcu);
 186         kfree(sf_acts);
 187 }
 188
 189 /* Schedules 'sf_acts' to be freed after the next RCU grace period.
 190  * The caller must hold rcu_read_lock for this to be sensible. */
 191 void flow_deferred_free_acts(struct sw_flow_actions *sf_acts)
 192 {
 193         call_rcu(&sf_acts->rcu, rcu_free_acts_callback);
 194 }
 195
 196 static void parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 197 {
 198         struct qtag_prefix {
 199                 __be16 eth_type; /* ETH_P_8021Q */
 200                 __be16 tci;
 201         };
 202         struct qtag_prefix *qp;
 203
 204         if (skb->len < sizeof(struct qtag_prefix) + sizeof(__be16))
 205                 return;
 206
 207         qp = (struct qtag_prefix *) skb->data;
 208         key->dl_tci = qp->tci | htons(VLAN_TAG_PRESENT);
 209         __skb_pull(skb, sizeof(struct qtag_prefix));
 210 }
 211
 212 static __be16 parse_ethertype(struct sk_buff *skb)
 213 {
 214         struct llc_snap_hdr {
 215                 u8  dsap;  /* Always 0xAA */
 216                 u8  ssap;  /* Always 0xAA */
 217                 u8  ctrl;
 218                 u8  oui[3];
 219                 __be16 ethertype;
 220         };
 221         struct llc_snap_hdr *llc;
 222         __be16 proto;
 223
 224         proto = *(__be16 *) skb->data;
 225         __skb_pull(skb, sizeof(__be16));
 226
 227         if (ntohs(proto) >= 1536)
 228                 return proto;
 229
 230         if (unlikely(skb->len < sizeof(struct llc_snap_hdr)))
 231                 return htons(ETH_P_802_2);
 232
 233         llc = (struct llc_snap_hdr *) skb->data;
 234         if (llc->dsap != LLC_SAP_SNAP ||
 235             llc->ssap != LLC_SAP_SNAP ||
 236             (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
 237                 return htons(ETH_P_802_2);
 238
 239         __skb_pull(skb, sizeof(struct llc_snap_hdr));
 240         return llc->ethertype;
 241 }
 242
 243 /**
 244  * flow_extract - extracts a flow key from an Ethernet frame.
 245  * @skb: sk_buff that contains the frame, with skb->data pointing to the
 246  * Ethernet header
 247  * @in_port: port number on which @skb was received.
 248  * @key: output flow key
 249  * @is_frag: set to 1 if @skb contains an IPv4 fragment, or to 0 if @skb does
 250  * not contain an IPv4 packet or if it is not a fragment.
 251  *
 252  * The caller must ensure that skb->len >= ETH_HLEN.
 253  *
 254  * Returns 0 if successful, otherwise a negative errno value.
 255  *
 256  * Initializes @skb header pointers as follows:
 257  *
 258  *    - skb->mac_header: the Ethernet header.
 259  *
 260  *    - skb->network_header: just past the Ethernet header, or just past the
 261  *      VLAN header, to the first byte of the Ethernet payload.
 262  *
 263  *    - skb->transport_header: If key->dl_type is ETH_P_IP on output, then just
 264  *      past the IPv4 header, if one is present and of a correct length,
 265  *      otherwise the same as skb->network_header.  For other key->dl_type
 266  *      values it is left untouched.
 267  */
 268 int flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key,
 269                  bool *is_frag)
 270 {
 271         struct ethhdr *eth;
 272
 273         memset(key, 0, sizeof(*key));
 274         key->tun_id = OVS_CB(skb)->tun_id;
 275         key->in_port = in_port;
 276         *is_frag = false;
 277
 278         /*
 279          * We would really like to pull as many bytes as we could possibly
 280          * want to parse into the linear data area.  Currently that is:
 281          *
 282          *    14     Ethernet header
 283          *     4     VLAN header
 284          *    60     max IP header with options
 285          *    20     max TCP/UDP/ICMP header (don't care about options)
 286          *    --
 287          *    98
 288          *
 289          * But Xen only allocates 64 or 72 bytes for the linear data area in
 290          * netback, which means that we would reallocate and copy the skb's
 291          * linear data on every packet if we did that.  So instead just pull 64
 292          * bytes, which is always sufficient without IP options, and then check
 293          * whether we need to pull more later when we look at the IP header.
 294          */
 295         if (!pskb_may_pull(skb, min(skb->len, 64u)))
 296                 return -ENOMEM;
 297
 298         skb_reset_mac_header(skb);
 299
 300         /* Link layer. */
 301         eth = eth_hdr(skb);
 302         memcpy(key->dl_src, eth->h_source, ETH_ALEN);
 303         memcpy(key->dl_dst, eth->h_dest, ETH_ALEN);
 304
 305         /* dl_type, dl_vlan, dl_vlan_pcp. */
 306         __skb_pull(skb, 2 * ETH_ALEN);
 307         if (eth->h_proto == htons(ETH_P_8021Q))
 308                 parse_vlan(skb, key);
 309         key->dl_type = parse_ethertype(skb);
 310         skb_reset_network_header(skb);
 311         __skb_push(skb, skb->data - (unsigned char *)eth);
 312
 313         /* Network layer. */
 314         if (key->dl_type == htons(ETH_P_IP)) {
 315                 struct iphdr *nh;
 316                 int error;
 317
 318                 error = check_iphdr(skb);
 319                 if (unlikely(error)) {
 320                         if (error == -EINVAL) {
 321                                 skb->transport_header = skb->network_header;
 322                                 return 0;
 323                         }
 324                         return error;
 325                 }
 326
 327                 nh = ip_hdr(skb);
 328                 key->nw_src = nh->saddr;
 329                 key->nw_dst = nh->daddr;
 330                 key->nw_tos = nh->tos & ~INET_ECN_MASK;
 331                 key->nw_proto = nh->protocol;
 332
 333                 /* Transport layer. */
 334                 if (!(nh->frag_off & htons(IP_MF | IP_OFFSET)) &&
 335                     !(skb_shinfo(skb)->gso_type & SKB_GSO_UDP)) {
 336                         if (key->nw_proto == IPPROTO_TCP) {
 337                                 if (tcphdr_ok(skb)) {
 338                                         struct tcphdr *tcp = tcp_hdr(skb);
 339                                         key->tp_src = tcp->source;
 340                                         key->tp_dst = tcp->dest;
 341                                 }
 342                         } else if (key->nw_proto == IPPROTO_UDP) {
 343                                 if (udphdr_ok(skb)) {
 344                                         struct udphdr *udp = udp_hdr(skb);
 345                                         key->tp_src = udp->source;
 346                                         key->tp_dst = udp->dest;
 347                                 }
 348                         } else if (key->nw_proto == IPPROTO_ICMP) {
 349                                 if (icmphdr_ok(skb)) {
 350                                         struct icmphdr *icmp = icmp_hdr(skb);
 351                                         /* The ICMP type and code fields use the 16-bit
 352                                          * transport port fields, so we need to store them
 353                                          * in 16-bit network byte order. */
 354                                         key->tp_src = htons(icmp->type);
 355                                         key->tp_dst = htons(icmp->code);
 356                                 }
 357                         }
 358                 } else
 359                         *is_frag = true;
 360
 361         } else if (key->dl_type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
 362                 struct arp_eth_header *arp;
 363
 364                 arp = (struct arp_eth_header *)skb_network_header(skb);
 365
 366                 if (arp->ar_hrd == htons(ARPHRD_ETHER)
 367                                 && arp->ar_pro == htons(ETH_P_IP)
 368                                 && arp->ar_hln == ETH_ALEN
 369                                 && arp->ar_pln == 4) {
 370
 371                         /* We only match on the lower 8 bits of the opcode. */
 372                         if (ntohs(arp->ar_op) <= 0xff)
 373                                 key->nw_proto = ntohs(arp->ar_op);
 374
 375                         if (key->nw_proto == ARPOP_REQUEST
 376                                         || key->nw_proto == ARPOP_REPLY) {
 377                                 memcpy(&key->nw_src, arp->ar_sip, sizeof(key->nw_src));
 378                                 memcpy(&key->nw_dst, arp->ar_tip, sizeof(key->nw_dst));
 379                         }
 380                 }
 381         }
 382         return 0;
 383 }
 384
 385 u32 flow_hash(const struct sw_flow_key *key)
 386 {
 387         return jhash2((u32*)key, sizeof(*key) / sizeof(u32), hash_seed);
 388 }
 389
 390 int flow_cmp(const struct tbl_node *node, void *key2_)
 391 {
 392         const struct sw_flow_key *key1 = &flow_cast(node)->key;
 393         const struct sw_flow_key *key2 = key2_;
 394
 395         return !memcmp(key1, key2, sizeof(struct sw_flow_key));
 396 }
 397
 398 /**
 399  * flow_from_nlattrs - parses Netlink attributes into a flow key.
 400  * @swkey: receives the extracted flow key.
 401  * @key: Netlink attribute holding nested %ODP_KEY_ATTR_* Netlink attribute
 402  * sequence.
 403  *
 404  * This state machine accepts the following forms, with [] for optional
 405  * elements and | for alternatives:
 406  *
 407  * [tun_id] in_port ethernet [8021q] [ethertype [IP [TCP|UDP|ICMP] | ARP]
 408  */
 409 int flow_from_nlattrs(struct sw_flow_key *swkey, const struct nlattr *attr)
 410 {
 411         const struct nlattr *nla;
 412         u16 prev_type;
 413         int rem;
 414
 415         memset(swkey, 0, sizeof(*swkey));
 416         swkey->dl_type = htons(ETH_P_802_2);
 417
 418         prev_type = ODP_KEY_ATTR_UNSPEC;
 419         nla_for_each_nested(nla, attr, rem) {
 420                 static const u32 key_lens[ODP_KEY_ATTR_MAX + 1] = {
 421                         [ODP_KEY_ATTR_TUN_ID] = 8,
 422                         [ODP_KEY_ATTR_IN_PORT] = 4,
 423                         [ODP_KEY_ATTR_ETHERNET] = sizeof(struct odp_key_ethernet),
 424                         [ODP_KEY_ATTR_8021Q] = sizeof(struct odp_key_8021q),
 425                         [ODP_KEY_ATTR_ETHERTYPE] = 2,
 426                         [ODP_KEY_ATTR_IPV4] = sizeof(struct odp_key_ipv4),
 427                         [ODP_KEY_ATTR_TCP] = sizeof(struct odp_key_tcp),
 428                         [ODP_KEY_ATTR_UDP] = sizeof(struct odp_key_udp),
 429                         [ODP_KEY_ATTR_ICMP] = sizeof(struct odp_key_icmp),
 430                         [ODP_KEY_ATTR_ARP] = sizeof(struct odp_key_arp),
 431                 };
 432
 433                 const struct odp_key_ethernet *eth_key;
 434                 const struct odp_key_8021q *q_key;
 435                 const struct odp_key_ipv4 *ipv4_key;
 436                 const struct odp_key_tcp *tcp_key;
 437                 const struct odp_key_udp *udp_key;
 438                 const struct odp_key_icmp *icmp_key;
 439                 const struct odp_key_arp *arp_key;
 440
 441                 int type = nla_type(nla);
 442
 443                 if (type > ODP_KEY_ATTR_MAX || nla_len(nla) != key_lens[type])
 444                         return -EINVAL;
 445
 446 #define TRANSITION(PREV_TYPE, TYPE) (((PREV_TYPE) << 16) | (TYPE))
 447                 switch (TRANSITION(prev_type, type)) {
 448                 case TRANSITION(ODP_KEY_ATTR_UNSPEC, ODP_KEY_ATTR_TUN_ID):
 449                         swkey->tun_id = nla_get_be64(nla);
 450                         break;
 451
 452                 case TRANSITION(ODP_KEY_ATTR_UNSPEC, ODP_KEY_ATTR_IN_PORT):
 453                 case TRANSITION(ODP_KEY_ATTR_TUN_ID, ODP_KEY_ATTR_IN_PORT):
 454                         if (nla_get_u32(nla) >= DP_MAX_PORTS)
 455                                 return -EINVAL;
 456                         swkey->in_port = nla_get_u32(nla);
 457                         break;
 458
 459                 case TRANSITION(ODP_KEY_ATTR_IN_PORT, ODP_KEY_ATTR_ETHERNET):
 460                         eth_key = nla_data(nla);
 461                         memcpy(swkey->dl_src, eth_key->eth_src, ETH_ALEN);
 462                         memcpy(swkey->dl_dst, eth_key->eth_dst, ETH_ALEN);
 463                         break;
 464
 465                 case TRANSITION(ODP_KEY_ATTR_ETHERNET, ODP_KEY_ATTR_8021Q):
 466                         q_key = nla_data(nla);
 467                         /* Only standard 0x8100 VLANs currently supported. */
 468                         if (q_key->q_tpid != htons(ETH_P_8021Q))
 469                                 return -EINVAL;
 470                         if (q_key->q_tci & htons(VLAN_TAG_PRESENT))
 471                                 return -EINVAL;
 472                         swkey->dl_tci = q_key->q_tci | htons(VLAN_TAG_PRESENT);
 473                         break;
 474
 475                 case TRANSITION(ODP_KEY_ATTR_8021Q, ODP_KEY_ATTR_ETHERTYPE):
 476                 case TRANSITION(ODP_KEY_ATTR_ETHERNET, ODP_KEY_ATTR_ETHERTYPE):
 477                         swkey->dl_type = nla_get_be16(nla);
 478                         if (ntohs(swkey->dl_type) < 1536)
 479                                 return -EINVAL;
 480                         break;
 481
 482                 case TRANSITION(ODP_KEY_ATTR_ETHERTYPE, ODP_KEY_ATTR_IPV4):
 483                         if (swkey->dl_type != htons(ETH_P_IP))
 484                                 return -EINVAL;
 485                         ipv4_key = nla_data(nla);
 486                         swkey->nw_src = ipv4_key->ipv4_src;
 487                         swkey->nw_dst = ipv4_key->ipv4_dst;
 488                         swkey->nw_proto = ipv4_key->ipv4_proto;
 489                         swkey->nw_tos = ipv4_key->ipv4_tos;
 490                         if (swkey->nw_tos & INET_ECN_MASK)
 491                                 return -EINVAL;
 492                         break;
 493
 494                 case TRANSITION(ODP_KEY_ATTR_IPV4, ODP_KEY_ATTR_TCP):
 495                         if (swkey->nw_proto != IPPROTO_TCP)
 496                                 return -EINVAL;
 497                         tcp_key = nla_data(nla);
 498                         swkey->tp_src = tcp_key->tcp_src;
 499                         swkey->tp_dst = tcp_key->tcp_dst;
 500                         break;
 501
 502                 case TRANSITION(ODP_KEY_ATTR_IPV4, ODP_KEY_ATTR_UDP):
 503                         if (swkey->nw_proto != IPPROTO_UDP)
 504                                 return -EINVAL;
 505                         udp_key = nla_data(nla);
 506                         swkey->tp_src = udp_key->udp_src;
 507                         swkey->tp_dst = udp_key->udp_dst;
 508                         break;
 509
 510                 case TRANSITION(ODP_KEY_ATTR_IPV4, ODP_KEY_ATTR_ICMP):
 511                         if (swkey->nw_proto != IPPROTO_ICMP)
 512                                 return -EINVAL;
 513                         icmp_key = nla_data(nla);
 514                         swkey->tp_src = htons(icmp_key->icmp_type);
 515                         swkey->tp_dst = htons(icmp_key->icmp_code);
 516                         break;
 517
 518                 case TRANSITION(ODP_KEY_ATTR_ETHERTYPE, ODP_KEY_ATTR_ARP):
 519                         if (swkey->dl_type != htons(ETH_P_ARP))
 520                                 return -EINVAL;
 521                         arp_key = nla_data(nla);
 522                         swkey->nw_src = arp_key->arp_sip;
 523                         swkey->nw_dst = arp_key->arp_tip;
 524                         if (arp_key->arp_op & htons(0xff00))
 525                                 return -EINVAL;
 526                         swkey->nw_proto = ntohs(arp_key->arp_op);
 527                         break;
 528
 529                 default:
 530                         return -EINVAL;
 531                 }
 532
 533                 prev_type = type;
 534         }
 535         if (rem)
 536                 return -EINVAL;
 537
 538         switch (prev_type) {
 539         case ODP_KEY_ATTR_UNSPEC:
 540                 return -EINVAL;
 541
 542         case ODP_KEY_ATTR_TUN_ID:
 543         case ODP_KEY_ATTR_IN_PORT:
 544                 return -EINVAL;
 545
 546         case ODP_KEY_ATTR_ETHERNET:
 547         case ODP_KEY_ATTR_8021Q:
 548                 return 0;
 549
 550         case ODP_KEY_ATTR_ETHERTYPE:
 551                 if (swkey->dl_type == htons(ETH_P_IP) ||
 552                     swkey->dl_type == htons(ETH_P_ARP))
 553                         return -EINVAL;
 554                 return 0;
 555
 556         case ODP_KEY_ATTR_IPV4:
 557                 if (swkey->nw_proto == IPPROTO_TCP ||
 558                     swkey->nw_proto == IPPROTO_UDP ||
 559                     swkey->nw_proto == IPPROTO_ICMP)
 560                         return -EINVAL;
 561                 return 0;
 562
 563         case ODP_KEY_ATTR_TCP:
 564         case ODP_KEY_ATTR_UDP:
 565         case ODP_KEY_ATTR_ICMP:
 566         case ODP_KEY_ATTR_ARP:
 567                 return 0;
 568         }
 569
 570         WARN_ON_ONCE(1);
 571         return -EINVAL;
 572 }
 573
 574 int flow_to_nlattrs(const struct sw_flow_key *swkey, struct sk_buff *skb)
 575 {
 576         struct odp_key_ethernet *eth_key;
 577         struct nlattr *nla;
 578
 579         if (swkey->tun_id != cpu_to_be64(0))
 580                 NLA_PUT_BE64(skb, ODP_KEY_ATTR_TUN_ID, swkey->tun_id);
 581
 582         NLA_PUT_U32(skb, ODP_KEY_ATTR_IN_PORT, swkey->in_port);
 583
 584         nla = nla_reserve(skb, ODP_KEY_ATTR_ETHERNET, sizeof(*eth_key));
 585         if (!nla)
 586                 goto nla_put_failure;
 587         eth_key = nla_data(nla);
 588         memcpy(eth_key->eth_src, swkey->dl_src, ETH_ALEN);
 589         memcpy(eth_key->eth_dst, swkey->dl_dst, ETH_ALEN);
 590
 591         if (swkey->dl_tci != htons(0)) {
 592                 struct odp_key_8021q q_key;
 593
 594                 q_key.q_tpid = htons(ETH_P_8021Q);
 595                 q_key.q_tci = swkey->dl_tci & ~htons(VLAN_TAG_PRESENT);
 596                 NLA_PUT(skb, ODP_KEY_ATTR_8021Q, sizeof(q_key), &q_key);
 597         }
 598
 599         if (swkey->dl_type == htons(ETH_P_802_2))
 600                 return 0;
 601
 602         NLA_PUT_BE16(skb, ODP_KEY_ATTR_ETHERTYPE, swkey->dl_type);
 603
 604         if (swkey->dl_type == htons(ETH_P_IP)) {
 605                 struct odp_key_ipv4 *ipv4_key;
 606
 607                 nla = nla_reserve(skb, ODP_KEY_ATTR_IPV4, sizeof(*ipv4_key));
 608                 if (!nla)
 609                         goto nla_put_failure;
 610                 ipv4_key = nla_data(nla);
 611                 ipv4_key->ipv4_src = swkey->nw_src;
 612                 ipv4_key->ipv4_dst = swkey->nw_dst;
 613                 ipv4_key->ipv4_proto = swkey->nw_proto;
 614                 ipv4_key->ipv4_tos = swkey->nw_tos;
 615
 616                 if (swkey->nw_proto == IPPROTO_TCP) {
 617                         struct odp_key_tcp *tcp_key;
 618
 619                         nla = nla_reserve(skb, ODP_KEY_ATTR_TCP, sizeof(*tcp_key));
 620                         if (!nla)
 621                                 goto nla_put_failure;
 622                         tcp_key = nla_data(nla);
 623                         tcp_key->tcp_src = swkey->tp_src;
 624                         tcp_key->tcp_dst = swkey->tp_dst;
 625                 } else if (swkey->nw_proto == IPPROTO_UDP) {
 626                         struct odp_key_udp *udp_key;
 627
 628                         nla = nla_reserve(skb, ODP_KEY_ATTR_UDP, sizeof(*udp_key));
 629                         if (!nla)
 630                                 goto nla_put_failure;
 631                         udp_key = nla_data(nla);
 632                         udp_key->udp_src = swkey->tp_src;
 633                         udp_key->udp_dst = swkey->tp_dst;
 634                 } else if (swkey->nw_proto == IPPROTO_ICMP) {
 635                         struct odp_key_icmp *icmp_key;
 636
 637                         nla = nla_reserve(skb, ODP_KEY_ATTR_ICMP, sizeof(*icmp_key));
 638                         if (!nla)
 639                                 goto nla_put_failure;
 640                         icmp_key = nla_data(nla);
 641                         icmp_key->icmp_type = ntohs(swkey->tp_src);
 642                         icmp_key->icmp_code = ntohs(swkey->tp_dst);
 643                 }
 644         } else if (swkey->dl_type == htons(ETH_P_ARP)) {
 645                 struct odp_key_arp *arp_key;
 646
 647                 nla = nla_reserve(skb, ODP_KEY_ATTR_ARP, sizeof(*arp_key));
 648                 if (!nla)
 649                         goto nla_put_failure;
 650                 arp_key = nla_data(nla);
 651                 arp_key->arp_sip = swkey->nw_src;
 652                 arp_key->arp_tip = swkey->nw_dst;
 653                 arp_key->arp_op = htons(swkey->nw_proto);
 654         }
 655
 656         return 0;
 657
 658 nla_put_failure:
 659         return -EMSGSIZE;
 660 }
 661
 662 /* Initializes the flow module.
 663  * Returns zero if successful or a negative error code. */
 664 int flow_init(void)
 665 {
 666         flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
 667                                         0, NULL);
 668         if (flow_cache == NULL)
 669                 return -ENOMEM;
 670
 671         get_random_bytes(&hash_seed, sizeof(hash_seed));
 672
 673         return 0;
 674 }
 675
 676 /* Uninitializes the flow module. */
 677 void flow_exit(void)
 678 {
 679         kmem_cache_destroy(flow_cache);
 680 }