lib/packets.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef PACKETS_H
  18 #define PACKETS_H 1
  19
  20 #include <inttypes.h>
  21 #include <sys/types.h>
  22 #include <netinet/in.h>
  23 #include <stdint.h>
  24 #include <string.h>
  25 #include "compiler.h"
  26 #include "flow.h"
  27 #include "openvswitch/types.h"
  28 #include "random.h"
  29 #include "util.h"
  30
  31 struct ofpbuf;
  32 struct ds;
  33
  34 /* Datapath packet metadata */
  35 struct pkt_metadata {
  36     uint32_t recirc_id;         /* Recirculation id carried with the
  37                                    recirculating packets. 0 for packets
  38                                    received from the wire. */
  39     uint32_t dp_hash;           /* hash value computed by the recirculation
  40                                    action. */
  41     struct flow_tnl tunnel;     /* Encapsulating tunnel parameters. */
  42     uint32_t skb_priority;      /* Packet priority for QoS. */
  43     uint32_t pkt_mark;          /* Packet mark. */
  44     union flow_in_port in_port; /* Input port. */
  45 };
  46
  47 #define PKT_METADATA_INITIALIZER(PORT) \
  48     (struct pkt_metadata){ 0, 0, { 0, 0, 0, 0, 0, 0}, 0, 0, {(PORT)} }
  49
  50 static inline struct pkt_metadata
  51 pkt_metadata_from_flow(const struct flow *flow)
  52 {
  53     struct pkt_metadata md;
  54
  55     md.recirc_id = flow->recirc_id;
  56     md.dp_hash = flow->dp_hash;
  57     md.tunnel = flow->tunnel;
  58     md.skb_priority = flow->skb_priority;
  59     md.pkt_mark = flow->pkt_mark;
  60     md.in_port = flow->in_port;
  61
  62     return md;
  63 }
  64
  65 bool dpid_from_string(const char *s, uint64_t *dpidp);
  66
  67 #define ETH_ADDR_LEN           6
  68
  69 static const uint8_t eth_addr_broadcast[ETH_ADDR_LEN] OVS_UNUSED
  70     = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  71
  72 static const uint8_t eth_addr_stp[ETH_ADDR_LEN] OVS_UNUSED
  73     = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x00 };
  74
  75 static const uint8_t eth_addr_lacp[ETH_ADDR_LEN] OVS_UNUSED
  76     = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x02 };
  77
  78 static const uint8_t eth_addr_bfd[ETH_ADDR_LEN] OVS_UNUSED
  79     = { 0x00, 0x23, 0x20, 0x00, 0x00, 0x01 };
  80
  81 static inline bool eth_addr_is_broadcast(const uint8_t ea[6])
  82 {
  83     return (ea[0] & ea[1] & ea[2] & ea[3] & ea[4] & ea[5]) == 0xff;
  84 }
  85
  86 static inline bool eth_addr_is_multicast(const uint8_t ea[6])
  87 {
  88     return ea[0] & 1;
  89 }
  90 static inline bool eth_addr_is_local(const uint8_t ea[6])
  91 {
  92     /* Local if it is either a locally administered address or a Nicira random
  93      * address. */
  94     return ea[0] & 2
  95        || (ea[0] == 0x00 && ea[1] == 0x23 && ea[2] == 0x20 && ea[3] & 0x80);
  96 }
  97 static inline bool eth_addr_is_zero(const uint8_t ea[6])
  98 {
  99     return !(ea[0] | ea[1] | ea[2] | ea[3] | ea[4] | ea[5]);
 100 }
 101
 102 static inline int eth_mask_is_exact(const uint8_t ea[ETH_ADDR_LEN])
 103 {
 104     return (ea[0] & ea[1] & ea[2] & ea[3] & ea[4] & ea[5]) == 0xff;
 105 }
 106
 107 static inline int eth_addr_compare_3way(const uint8_t a[ETH_ADDR_LEN],
 108                                         const uint8_t b[ETH_ADDR_LEN])
 109 {
 110     return memcmp(a, b, ETH_ADDR_LEN);
 111 }
 112 static inline bool eth_addr_equals(const uint8_t a[ETH_ADDR_LEN],
 113                                    const uint8_t b[ETH_ADDR_LEN])
 114 {
 115     return !eth_addr_compare_3way(a, b);
 116 }
 117 static inline bool eth_addr_equal_except(const uint8_t a[ETH_ADDR_LEN],
 118                                     const uint8_t b[ETH_ADDR_LEN],
 119                                     const uint8_t mask[ETH_ADDR_LEN])
 120 {
 121     return !(((a[0] ^ b[0]) & mask[0])
 122              || ((a[1] ^ b[1]) & mask[1])
 123              || ((a[2] ^ b[2]) & mask[2])
 124              || ((a[3] ^ b[3]) & mask[3])
 125              || ((a[4] ^ b[4]) & mask[4])
 126              || ((a[5] ^ b[5]) & mask[5]));
 127 }
 128 static inline uint64_t eth_addr_to_uint64(const uint8_t ea[ETH_ADDR_LEN])
 129 {
 130     return (((uint64_t) ea[0] << 40)
 131             | ((uint64_t) ea[1] << 32)
 132             | ((uint64_t) ea[2] << 24)
 133             | ((uint64_t) ea[3] << 16)
 134             | ((uint64_t) ea[4] << 8)
 135             | ea[5]);
 136 }
 137 static inline void eth_addr_from_uint64(uint64_t x, uint8_t ea[ETH_ADDR_LEN])
 138 {
 139     ea[0] = x >> 40;
 140     ea[1] = x >> 32;
 141     ea[2] = x >> 24;
 142     ea[3] = x >> 16;
 143     ea[4] = x >> 8;
 144     ea[5] = x;
 145 }
 146 static inline void eth_addr_mark_random(uint8_t ea[ETH_ADDR_LEN])
 147 {
 148     ea[0] &= ~1;                /* Unicast. */
 149     ea[0] |= 2;                 /* Private. */
 150 }
 151 static inline void eth_addr_random(uint8_t ea[ETH_ADDR_LEN])
 152 {
 153     random_bytes(ea, ETH_ADDR_LEN);
 154     eth_addr_mark_random(ea);
 155 }
 156 static inline void eth_addr_nicira_random(uint8_t ea[ETH_ADDR_LEN])
 157 {
 158     eth_addr_random(ea);
 159
 160     /* Set the OUI to the Nicira one. */
 161     ea[0] = 0x00;
 162     ea[1] = 0x23;
 163     ea[2] = 0x20;
 164
 165     /* Set the top bit to indicate random Nicira address. */
 166     ea[3] |= 0x80;
 167 }
 168
 169 bool eth_addr_is_reserved(const uint8_t ea[ETH_ADDR_LEN]);
 170 bool eth_addr_from_string(const char *, uint8_t ea[ETH_ADDR_LEN]);
 171
 172 void compose_rarp(struct ofpbuf *, const uint8_t eth_src[ETH_ADDR_LEN]);
 173
 174 void eth_push_vlan(struct ofpbuf *, ovs_be16 tpid, ovs_be16 tci);
 175 void eth_pop_vlan(struct ofpbuf *);
 176
 177 const char *eth_from_hex(const char *hex, struct ofpbuf **packetp);
 178 void eth_format_masked(const uint8_t eth[ETH_ADDR_LEN],
 179                        const uint8_t mask[ETH_ADDR_LEN], struct ds *s);
 180 void eth_addr_bitand(const uint8_t src[ETH_ADDR_LEN],
 181                      const uint8_t mask[ETH_ADDR_LEN],
 182                      uint8_t dst[ETH_ADDR_LEN]);
 183
 184 void set_mpls_lse(struct ofpbuf *, ovs_be32 label);
 185 void push_mpls(struct ofpbuf *packet, ovs_be16 ethtype, ovs_be32 lse);
 186 void pop_mpls(struct ofpbuf *, ovs_be16 ethtype);
 187
 188 void set_mpls_lse_ttl(ovs_be32 *lse, uint8_t ttl);
 189 void set_mpls_lse_tc(ovs_be32 *lse, uint8_t tc);
 190 void set_mpls_lse_label(ovs_be32 *lse, ovs_be32 label);
 191 void set_mpls_lse_bos(ovs_be32 *lse, uint8_t bos);
 192 ovs_be32 set_mpls_lse_values(uint8_t ttl, uint8_t tc, uint8_t bos,
 193                              ovs_be32 label);
 194
 195 /* Example:
 196  *
 197  * uint8_t mac[ETH_ADDR_LEN];
 198  *    [...]
 199  * printf("The Ethernet address is "ETH_ADDR_FMT"\n", ETH_ADDR_ARGS(mac));
 200  *
 201  */
 202 #define ETH_ADDR_FMT                                                    \
 203     "%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8
 204 #define ETH_ADDR_ARGS(ea)                                   \
 205     (ea)[0], (ea)[1], (ea)[2], (ea)[3], (ea)[4], (ea)[5]
 206
 207 /* Example:
 208  *
 209  * char *string = "1 00:11:22:33:44:55 2";
 210  * uint8_t mac[ETH_ADDR_LEN];
 211  * int a, b;
 212  *
 213  * if (ovs_scan(string, "%d"ETH_ADDR_SCAN_FMT"%d",
 214  *              &a, ETH_ADDR_SCAN_ARGS(mac), &b)) {
 215  *     ...
 216  * }
 217  */
 218 #define ETH_ADDR_SCAN_FMT "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8
 219 #define ETH_ADDR_SCAN_ARGS(ea) \
 220         &(ea)[0], &(ea)[1], &(ea)[2], &(ea)[3], &(ea)[4], &(ea)[5]
 221
 222 #define ETH_TYPE_IP            0x0800
 223 #define ETH_TYPE_ARP           0x0806
 224 #define ETH_TYPE_VLAN_8021Q    0x8100
 225 #define ETH_TYPE_VLAN          ETH_TYPE_VLAN_8021Q
 226 #define ETH_TYPE_VLAN_8021AD   0x88a8
 227 #define ETH_TYPE_IPV6          0x86dd
 228 #define ETH_TYPE_LACP          0x8809
 229 #define ETH_TYPE_RARP          0x8035
 230 #define ETH_TYPE_MPLS          0x8847
 231 #define ETH_TYPE_MPLS_MCAST    0x8848
 232
 233 static inline bool eth_type_mpls(ovs_be16 eth_type)
 234 {
 235     return eth_type == htons(ETH_TYPE_MPLS) ||
 236         eth_type == htons(ETH_TYPE_MPLS_MCAST);
 237 }
 238
 239 /* Minimum value for an Ethernet type.  Values below this are IEEE 802.2 frame
 240  * lengths. */
 241 #define ETH_TYPE_MIN           0x600
 242
 243 #define ETH_HEADER_LEN 14
 244 #define ETH_PAYLOAD_MIN 46
 245 #define ETH_PAYLOAD_MAX 1500
 246 #define ETH_TOTAL_MIN (ETH_HEADER_LEN + ETH_PAYLOAD_MIN)
 247 #define ETH_TOTAL_MAX (ETH_HEADER_LEN + ETH_PAYLOAD_MAX)
 248 #define ETH_VLAN_TOTAL_MAX (ETH_HEADER_LEN + VLAN_HEADER_LEN + ETH_PAYLOAD_MAX)
 249 OVS_PACKED(
 250 struct eth_header {
 251     uint8_t eth_dst[ETH_ADDR_LEN];
 252     uint8_t eth_src[ETH_ADDR_LEN];
 253     ovs_be16 eth_type;
 254 });
 255 BUILD_ASSERT_DECL(ETH_HEADER_LEN == sizeof(struct eth_header));
 256
 257 #define LLC_DSAP_SNAP 0xaa
 258 #define LLC_SSAP_SNAP 0xaa
 259 #define LLC_CNTL_SNAP 3
 260
 261 #define LLC_HEADER_LEN 3
 262 OVS_PACKED(
 263 struct llc_header {
 264     uint8_t llc_dsap;
 265     uint8_t llc_ssap;
 266     uint8_t llc_cntl;
 267 });
 268 BUILD_ASSERT_DECL(LLC_HEADER_LEN == sizeof(struct llc_header));
 269
 270 #define SNAP_ORG_ETHERNET "\0\0" /* The compiler adds a null byte, so
 271                                     sizeof(SNAP_ORG_ETHERNET) == 3. */
 272 #define SNAP_HEADER_LEN 5
 273 OVS_PACKED(
 274 struct snap_header {
 275     uint8_t snap_org[3];
 276     ovs_be16 snap_type;
 277 });
 278 BUILD_ASSERT_DECL(SNAP_HEADER_LEN == sizeof(struct snap_header));
 279
 280 #define LLC_SNAP_HEADER_LEN (LLC_HEADER_LEN + SNAP_HEADER_LEN)
 281 OVS_PACKED(
 282 struct llc_snap_header {
 283     struct llc_header llc;
 284     struct snap_header snap;
 285 });
 286 BUILD_ASSERT_DECL(LLC_SNAP_HEADER_LEN == sizeof(struct llc_snap_header));
 287
 288 #define VLAN_VID_MASK 0x0fff
 289 #define VLAN_VID_SHIFT 0
 290
 291 #define VLAN_PCP_MASK 0xe000
 292 #define VLAN_PCP_SHIFT 13
 293
 294 #define VLAN_CFI 0x1000
 295 #define VLAN_CFI_SHIFT 12
 296
 297 /* Given the vlan_tci field from an 802.1Q header, in network byte order,
 298  * returns the VLAN ID in host byte order. */
 299 static inline uint16_t
 300 vlan_tci_to_vid(ovs_be16 vlan_tci)
 301 {
 302     return (ntohs(vlan_tci) & VLAN_VID_MASK) >> VLAN_VID_SHIFT;
 303 }
 304
 305 /* Given the vlan_tci field from an 802.1Q header, in network byte order,
 306  * returns the priority code point (PCP) in host byte order. */
 307 static inline int
 308 vlan_tci_to_pcp(ovs_be16 vlan_tci)
 309 {
 310     return (ntohs(vlan_tci) & VLAN_PCP_MASK) >> VLAN_PCP_SHIFT;
 311 }
 312
 313 /* Given the vlan_tci field from an 802.1Q header, in network byte order,
 314  * returns the Canonical Format Indicator (CFI). */
 315 static inline int
 316 vlan_tci_to_cfi(ovs_be16 vlan_tci)
 317 {
 318     return (vlan_tci & htons(VLAN_CFI)) != 0;
 319 }
 320
 321 #define VLAN_HEADER_LEN 4
 322 struct vlan_header {
 323     ovs_be16 vlan_tci;          /* Lowest 12 bits are VLAN ID. */
 324     ovs_be16 vlan_next_type;
 325 };
 326 BUILD_ASSERT_DECL(VLAN_HEADER_LEN == sizeof(struct vlan_header));
 327
 328 #define VLAN_ETH_HEADER_LEN (ETH_HEADER_LEN + VLAN_HEADER_LEN)
 329 OVS_PACKED(
 330 struct vlan_eth_header {
 331     uint8_t veth_dst[ETH_ADDR_LEN];
 332     uint8_t veth_src[ETH_ADDR_LEN];
 333     ovs_be16 veth_type;         /* Always htons(ETH_TYPE_VLAN). */
 334     ovs_be16 veth_tci;          /* Lowest 12 bits are VLAN ID. */
 335     ovs_be16 veth_next_type;
 336 });
 337 BUILD_ASSERT_DECL(VLAN_ETH_HEADER_LEN == sizeof(struct vlan_eth_header));
 338
 339 /* MPLS related definitions */
 340 #define MPLS_TTL_MASK       0x000000ff
 341 #define MPLS_TTL_SHIFT      0
 342
 343 #define MPLS_BOS_MASK       0x00000100
 344 #define MPLS_BOS_SHIFT      8
 345
 346 #define MPLS_TC_MASK        0x00000e00
 347 #define MPLS_TC_SHIFT       9
 348
 349 #define MPLS_LABEL_MASK     0xfffff000
 350 #define MPLS_LABEL_SHIFT    12
 351
 352 #define MPLS_HLEN           4
 353
 354 struct mpls_hdr {
 355     ovs_be32 mpls_lse;
 356 };
 357 BUILD_ASSERT_DECL(MPLS_HLEN == sizeof(struct mpls_hdr));
 358
 359 /* Given a mpls label stack entry in network byte order
 360  * return mpls label in host byte order */
 361 static inline uint32_t
 362 mpls_lse_to_label(ovs_be32 mpls_lse)
 363 {
 364     return (ntohl(mpls_lse) & MPLS_LABEL_MASK) >> MPLS_LABEL_SHIFT;
 365 }
 366
 367 /* Given a mpls label stack entry in network byte order
 368  * return mpls tc */
 369 static inline uint8_t
 370 mpls_lse_to_tc(ovs_be32 mpls_lse)
 371 {
 372     return (ntohl(mpls_lse) & MPLS_TC_MASK) >> MPLS_TC_SHIFT;
 373 }
 374
 375 /* Given a mpls label stack entry in network byte order
 376  * return mpls ttl */
 377 static inline uint8_t
 378 mpls_lse_to_ttl(ovs_be32 mpls_lse)
 379 {
 380     return (ntohl(mpls_lse) & MPLS_TTL_MASK) >> MPLS_TTL_SHIFT;
 381 }
 382
 383 /* Set TTL in mpls lse. */
 384 static inline void
 385 flow_set_mpls_lse_ttl(ovs_be32 *mpls_lse, uint8_t ttl)
 386 {
 387     *mpls_lse &= ~htonl(MPLS_TTL_MASK);
 388     *mpls_lse |= htonl(ttl << MPLS_TTL_SHIFT);
 389 }
 390
 391 /* Given a mpls label stack entry in network byte order
 392  * return mpls BoS bit  */
 393 static inline uint8_t
 394 mpls_lse_to_bos(ovs_be32 mpls_lse)
 395 {
 396     return (mpls_lse & htonl(MPLS_BOS_MASK)) != 0;
 397 }
 398
 399 #define IP_FMT "%"PRIu32".%"PRIu32".%"PRIu32".%"PRIu32
 400 #define IP_ARGS(ip)                             \
 401     ntohl(ip) >> 24,                            \
 402     (ntohl(ip) >> 16) & 0xff,                   \
 403     (ntohl(ip) >> 8) & 0xff,                    \
 404     ntohl(ip) & 0xff
 405
 406 /* Example:
 407  *
 408  * char *string = "1 33.44.55.66 2";
 409  * ovs_be32 ip;
 410  * int a, b;
 411  *
 412  * if (ovs_scan(string, "%d"IP_SCAN_FMT"%d", &a, IP_SCAN_ARGS(&ip), &b)) {
 413  *     ...
 414  * }
 415  */
 416 #define IP_SCAN_FMT "%"SCNu8".%"SCNu8".%"SCNu8".%"SCNu8
 417 #define IP_SCAN_ARGS(ip)                                    \
 418         ((void) (ovs_be32) *(ip), &((uint8_t *) ip)[0]),    \
 419         &((uint8_t *) ip)[1],                               \
 420         &((uint8_t *) ip)[2],                               \
 421         &((uint8_t *) ip)[3]
 422
 423 /* Returns true if 'netmask' is a CIDR netmask, that is, if it consists of N
 424  * high-order 1-bits and 32-N low-order 0-bits. */
 425 static inline bool
 426 ip_is_cidr(ovs_be32 netmask)
 427 {
 428     uint32_t x = ~ntohl(netmask);
 429     return !(x & (x + 1));
 430 }
 431 static inline bool
 432 ip_is_multicast(ovs_be32 ip)
 433 {
 434     return (ip & htonl(0xf0000000)) == htonl(0xe0000000);
 435 }
 436 int ip_count_cidr_bits(ovs_be32 netmask);
 437 void ip_format_masked(ovs_be32 ip, ovs_be32 mask, struct ds *);
 438
 439 #define IP_VER(ip_ihl_ver) ((ip_ihl_ver) >> 4)
 440 #define IP_IHL(ip_ihl_ver) ((ip_ihl_ver) & 15)
 441 #define IP_IHL_VER(ihl, ver) (((ver) << 4) | (ihl))
 442
 443 #ifndef IPPROTO_SCTP
 444 #define IPPROTO_SCTP 132
 445 #endif
 446
 447 /* TOS fields. */
 448 #define IP_ECN_NOT_ECT 0x0
 449 #define IP_ECN_ECT_1 0x01
 450 #define IP_ECN_ECT_0 0x02
 451 #define IP_ECN_CE 0x03
 452 #define IP_ECN_MASK 0x03
 453 #define IP_DSCP_MASK 0xfc
 454
 455 #define IP_VERSION 4
 456
 457 #define IP_DONT_FRAGMENT  0x4000 /* Don't fragment. */
 458 #define IP_MORE_FRAGMENTS 0x2000 /* More fragments. */
 459 #define IP_FRAG_OFF_MASK  0x1fff /* Fragment offset. */
 460 #define IP_IS_FRAGMENT(ip_frag_off) \
 461         ((ip_frag_off) & htons(IP_MORE_FRAGMENTS | IP_FRAG_OFF_MASK))
 462
 463 #define IP_HEADER_LEN 20
 464 struct ip_header {
 465     uint8_t ip_ihl_ver;
 466     uint8_t ip_tos;
 467     ovs_be16 ip_tot_len;
 468     ovs_be16 ip_id;
 469     ovs_be16 ip_frag_off;
 470     uint8_t ip_ttl;
 471     uint8_t ip_proto;
 472     ovs_be16 ip_csum;
 473     ovs_16aligned_be32 ip_src;
 474     ovs_16aligned_be32 ip_dst;
 475 };
 476 BUILD_ASSERT_DECL(IP_HEADER_LEN == sizeof(struct ip_header));
 477
 478 #define ICMP_HEADER_LEN 8
 479 struct icmp_header {
 480     uint8_t icmp_type;
 481     uint8_t icmp_code;
 482     ovs_be16 icmp_csum;
 483     union {
 484         struct {
 485             ovs_be16 id;
 486             ovs_be16 seq;
 487         } echo;
 488         struct {
 489             ovs_be16 empty;
 490             ovs_be16 mtu;
 491         } frag;
 492         ovs_16aligned_be32 gateway;
 493     } icmp_fields;
 494     uint8_t icmp_data[0];
 495 };
 496 BUILD_ASSERT_DECL(ICMP_HEADER_LEN == sizeof(struct icmp_header));
 497
 498 #define SCTP_HEADER_LEN 12
 499 struct sctp_header {
 500     ovs_be16 sctp_src;
 501     ovs_be16 sctp_dst;
 502     ovs_be32 sctp_vtag;
 503     ovs_be32 sctp_csum;
 504 };
 505 BUILD_ASSERT_DECL(SCTP_HEADER_LEN == sizeof(struct sctp_header));
 506
 507 #define UDP_HEADER_LEN 8
 508 struct udp_header {
 509     ovs_be16 udp_src;
 510     ovs_be16 udp_dst;
 511     ovs_be16 udp_len;
 512     ovs_be16 udp_csum;
 513 };
 514 BUILD_ASSERT_DECL(UDP_HEADER_LEN == sizeof(struct udp_header));
 515
 516 #define TCP_FIN 0x001
 517 #define TCP_SYN 0x002
 518 #define TCP_RST 0x004
 519 #define TCP_PSH 0x008
 520 #define TCP_ACK 0x010
 521 #define TCP_URG 0x020
 522 #define TCP_ECE 0x040
 523 #define TCP_CWR 0x080
 524 #define TCP_NS  0x100
 525
 526 #define TCP_CTL(flags, offset) (htons((flags) | ((offset) << 12)))
 527 #define TCP_FLAGS(tcp_ctl) (ntohs(tcp_ctl) & 0x0fff)
 528 #define TCP_OFFSET(tcp_ctl) (ntohs(tcp_ctl) >> 12)
 529
 530 #define TCP_HEADER_LEN 20
 531 struct tcp_header {
 532     ovs_be16 tcp_src;
 533     ovs_be16 tcp_dst;
 534     ovs_16aligned_be32 tcp_seq;
 535     ovs_16aligned_be32 tcp_ack;
 536     ovs_be16 tcp_ctl;
 537     ovs_be16 tcp_winsz;
 538     ovs_be16 tcp_csum;
 539     ovs_be16 tcp_urg;
 540 };
 541 BUILD_ASSERT_DECL(TCP_HEADER_LEN == sizeof(struct tcp_header));
 542
 543 #define ARP_HRD_ETHERNET 1
 544 #define ARP_PRO_IP 0x0800
 545 #define ARP_OP_REQUEST 1
 546 #define ARP_OP_REPLY 2
 547 #define ARP_OP_RARP 3
 548
 549 #define ARP_ETH_HEADER_LEN 28
 550 struct arp_eth_header {
 551     /* Generic members. */
 552     ovs_be16 ar_hrd;           /* Hardware type. */
 553     ovs_be16 ar_pro;           /* Protocol type. */
 554     uint8_t ar_hln;            /* Hardware address length. */
 555     uint8_t ar_pln;            /* Protocol address length. */
 556     ovs_be16 ar_op;            /* Opcode. */
 557
 558     /* Ethernet+IPv4 specific members. */
 559     uint8_t ar_sha[ETH_ADDR_LEN]; /* Sender hardware address. */
 560     ovs_16aligned_be32 ar_spa;           /* Sender protocol address. */
 561     uint8_t ar_tha[ETH_ADDR_LEN]; /* Target hardware address. */
 562     ovs_16aligned_be32 ar_tpa;           /* Target protocol address. */
 563 };
 564 BUILD_ASSERT_DECL(ARP_ETH_HEADER_LEN == sizeof(struct arp_eth_header));
 565
 566 /* Like struct in6_addr, but whereas that struct requires 32-bit alignment on
 567  * most implementations, this one only requires 16-bit alignment. */
 568 union ovs_16aligned_in6_addr {
 569     ovs_be16 be16[8];
 570     ovs_16aligned_be32 be32[4];
 571 };
 572
 573 /* Like struct in6_hdr, but whereas that struct requires 32-bit alignment, this
 574  * one only requires 16-bit alignment. */
 575 struct ovs_16aligned_ip6_hdr {
 576     union {
 577         struct ovs_16aligned_ip6_hdrctl {
 578             ovs_16aligned_be32 ip6_un1_flow;
 579             ovs_be16 ip6_un1_plen;
 580             uint8_t ip6_un1_nxt;
 581             uint8_t ip6_un1_hlim;
 582         } ip6_un1;
 583         uint8_t ip6_un2_vfc;
 584     } ip6_ctlun;
 585     union ovs_16aligned_in6_addr ip6_src;
 586     union ovs_16aligned_in6_addr ip6_dst;
 587 };
 588
 589 /* Like struct in6_frag, but whereas that struct requires 32-bit alignment,
 590  * this one only requires 16-bit alignment. */
 591 struct ovs_16aligned_ip6_frag {
 592     uint8_t ip6f_nxt;
 593     uint8_t ip6f_reserved;
 594     ovs_be16 ip6f_offlg;
 595     ovs_16aligned_be32 ip6f_ident;
 596 };
 597
 598 /* The IPv6 flow label is in the lower 20 bits of the first 32-bit word. */
 599 #define IPV6_LABEL_MASK 0x000fffff
 600
 601 /* Example:
 602  *
 603  * char *string = "1 ::1 2";
 604  * char ipv6_s[IPV6_SCAN_LEN + 1];
 605  * struct in6_addr ipv6;
 606  *
 607  * if (ovs_scan(string, "%d"IPV6_SCAN_FMT"%d", &a, ipv6_s, &b)
 608  *     && inet_pton(AF_INET6, ipv6_s, &ipv6) == 1) {
 609  *     ...
 610  * }
 611  */
 612 #define IPV6_SCAN_FMT "%46[0123456789abcdefABCDEF:.]"
 613 #define IPV6_SCAN_LEN 46
 614
 615 extern const struct in6_addr in6addr_exact;
 616 #define IN6ADDR_EXACT_INIT { { { 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff, \
 617                                  0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff } } }
 618
 619 static inline bool ipv6_addr_equals(const struct in6_addr *a,
 620                                     const struct in6_addr *b)
 621 {
 622 #ifdef IN6_ARE_ADDR_EQUAL
 623     return IN6_ARE_ADDR_EQUAL(a, b);
 624 #else
 625     return !memcmp(a, b, sizeof(*a));
 626 #endif
 627 }
 628
 629 static inline bool ipv6_mask_is_any(const struct in6_addr *mask) {
 630     return ipv6_addr_equals(mask, &in6addr_any);
 631 }
 632
 633 static inline bool ipv6_mask_is_exact(const struct in6_addr *mask) {
 634     return ipv6_addr_equals(mask, &in6addr_exact);
 635 }
 636
 637 static inline bool dl_type_is_ip_any(ovs_be16 dl_type)
 638 {
 639     return dl_type == htons(ETH_TYPE_IP)
 640         || dl_type == htons(ETH_TYPE_IPV6);
 641 }
 642
 643 static inline bool is_ip_any(const struct flow *flow)
 644 {
 645     return dl_type_is_ip_any(flow->dl_type);
 646 }
 647
 648 static inline bool is_icmpv4(const struct flow *flow)
 649 {
 650     return (flow->dl_type == htons(ETH_TYPE_IP)
 651             && flow->nw_proto == IPPROTO_ICMP);
 652 }
 653
 654 static inline bool is_icmpv6(const struct flow *flow)
 655 {
 656     return (flow->dl_type == htons(ETH_TYPE_IPV6)
 657             && flow->nw_proto == IPPROTO_ICMPV6);
 658 }
 659
 660 void format_ipv6_addr(char *addr_str, const struct in6_addr *addr);
 661 void print_ipv6_addr(struct ds *string, const struct in6_addr *addr);
 662 void print_ipv6_masked(struct ds *string, const struct in6_addr *addr,
 663                        const struct in6_addr *mask);
 664 struct in6_addr ipv6_addr_bitand(const struct in6_addr *src,
 665                                  const struct in6_addr *mask);
 666 struct in6_addr ipv6_create_mask(int mask);
 667 int ipv6_count_cidr_bits(const struct in6_addr *netmask);
 668 bool ipv6_is_cidr(const struct in6_addr *netmask);
 669
 670 void *eth_compose(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
 671                   const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
 672                   size_t size);
 673 void *snap_compose(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
 674                    const uint8_t eth_src[ETH_ADDR_LEN],
 675                    unsigned int oui, uint16_t snap_type, size_t size);
 676 void packet_set_ipv4(struct ofpbuf *, ovs_be32 src, ovs_be32 dst, uint8_t tos,
 677                      uint8_t ttl);
 678 void packet_set_ipv6(struct ofpbuf *, uint8_t proto, const ovs_be32 src[4],
 679                      const ovs_be32 dst[4], uint8_t tc,
 680                      ovs_be32 fl, uint8_t hlmit);
 681 void packet_set_tcp_port(struct ofpbuf *, ovs_be16 src, ovs_be16 dst);
 682 void packet_set_udp_port(struct ofpbuf *, ovs_be16 src, ovs_be16 dst);
 683 void packet_set_sctp_port(struct ofpbuf *, ovs_be16 src, ovs_be16 dst);
 684
 685 void packet_format_tcp_flags(struct ds *, uint16_t);
 686 const char *packet_tcp_flag_to_string(uint32_t flag);
 687
 688 #endif /* packets.h */