text: /*
   * Copyright (c) 2008, 2009, 2010 Nicira Networks.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifndef PACKETS_H
  #define PACKETS_H 1
  
  #include <inttypes.h>
  #include <sys/types.h>
  #include <netinet/in.h>
  #include <stdint.h>
  #include <string.h>
  #include "compiler.h"
  #include "openvswitch/types.h"
  #include "random.h"
  #include "util.h"
  
  struct ofpbuf;
  struct ds;
  
  bool dpid_from_string(const char *s, uint64_t *dpidp);
  
  #define ETH_ADDR_LEN           6
  
  static const uint8_t eth_addr_broadcast[ETH_ADDR_LEN] OVS_UNUSED
      = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  
  static const uint8_t eth_addr_stp[ETH_ADDR_LEN] OVS_UNUSED
      = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x01 };
  
  static const uint8_t eth_addr_lacp[ETH_ADDR_LEN] OVS_UNUSED
      = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x02 };
  
  static inline bool eth_addr_is_broadcast(const uint8_t ea[6])
  {
      return (ea[0] & ea[1] & ea[2] & ea[3] & ea[4] & ea[5]) == 0xff;
  }
  
  static inline bool eth_addr_is_multicast(const uint8_t ea[6])
  {
      return ea[0] & 1;
  }
  static inline bool eth_addr_is_local(const uint8_t ea[6])
  {
      /* Local if it is either a locally administered address or a Nicira random
       * address. */
      return !!(ea[0] & 2)
         || (ea[0] == 0x00 && ea[1] == 0x23 && ea[2] == 0x20 && !!(ea[3] & 0x80));
  }
  static inline bool eth_addr_is_zero(const uint8_t ea[6])
  {
      return !(ea[0] | ea[1] | ea[2] | ea[3] | ea[4] | ea[5]);
  }
  static inline int eth_addr_compare_3way(const uint8_t a[ETH_ADDR_LEN],
                                          const uint8_t b[ETH_ADDR_LEN])
  {
      return memcmp(a, b, ETH_ADDR_LEN);
  }
  static inline bool eth_addr_equals(const uint8_t a[ETH_ADDR_LEN],
                                     const uint8_t b[ETH_ADDR_LEN])
  {
      return !eth_addr_compare_3way(a, b);
  }
  static inline uint64_t eth_addr_to_uint64(const uint8_t ea[ETH_ADDR_LEN])
  {
      return (((uint64_t) ea[0] << 40)
              | ((uint64_t) ea[1] << 32)
              | ((uint64_t) ea[2] << 24)
              | ((uint64_t) ea[3] << 16)
              | ((uint64_t) ea[4] << 8)
              | ea[5]);
  }
  static inline void eth_addr_from_uint64(uint64_t x, uint8_t ea[ETH_ADDR_LEN])
  {
      ea[0] = x >> 40;
      ea[1] = x >> 32;
      ea[2] = x >> 24;
      ea[3] = x >> 16;
      ea[4] = x >> 8;
      ea[5] = x;
  }
  static inline void eth_addr_mark_random(uint8_t ea[ETH_ADDR_LEN])
  {
      ea[0] &= ~1;                /* Unicast. */
      ea[0] |= 2;                 /* Private. */
  }
  static inline void eth_addr_random(uint8_t ea[ETH_ADDR_LEN])
  {
      random_bytes(ea, ETH_ADDR_LEN);
      eth_addr_mark_random(ea);
  }
  static inline void eth_addr_nicira_random(uint8_t ea[ETH_ADDR_LEN])
  {
      eth_addr_random(ea);
  
      /* Set the OUI to the Nicira one. */
      ea[0] = 0x00;
      ea[1] = 0x23;
      ea[2] = 0x20;
  
      /* Set the top bit to indicate random Nicira address. */
      ea[3] |= 0x80;
  }
  /* Returns true if 'ea' is a reserved multicast address, that a bridge must
   * never forward, false otherwise. */
  static inline bool eth_addr_is_reserved(const uint8_t ea[ETH_ADDR_LEN])
  {
      return (ea[0] == 0x01
              && ea[1] == 0x80
              && ea[2] == 0xc2
              && ea[3] == 0x00
              && ea[4] == 0x00
              && (ea[5] & 0xf0) == 0x00);
  }
  
  bool eth_addr_from_string(const char *, uint8_t ea[ETH_ADDR_LEN]);
  
  void compose_benign_packet(struct ofpbuf *, const char *tag,
                             uint16_t snap_type,
                             const uint8_t eth_src[ETH_ADDR_LEN]);
  
  /* Example:
   *
   * uint8_t mac[ETH_ADDR_LEN];
   *    [...]
   * printf("The Ethernet address is "ETH_ADDR_FMT"\n", ETH_ADDR_ARGS(mac));
   *
   */
  #define ETH_ADDR_FMT                                                    \
      "%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8
  #define ETH_ADDR_ARGS(ea)                                   \
      (ea)[0], (ea)[1], (ea)[2], (ea)[3], (ea)[4], (ea)[5]
  
  /* Example:
   *
   * char *string = "1 00:11:22:33:44:55 2";
   * uint8_t mac[ETH_ADDR_LEN];
   * int a, b;
   *
   * if (sscanf(string, "%d"ETH_ADDR_SCAN_FMT"%d",
   *     &a, ETH_ADDR_SCAN_ARGS(mac), &b) == 1 + ETH_ADDR_SCAN_COUNT + 1) {
   *     ...
   * }
   */
  #define ETH_ADDR_SCAN_FMT "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8
  #define ETH_ADDR_SCAN_ARGS(ea) \
          &(ea)[0], &(ea)[1], &(ea)[2], &(ea)[3], &(ea)[4], &(ea)[5]
  #define ETH_ADDR_SCAN_COUNT 6
  
  #define ETH_TYPE_IP            0x0800
  #define ETH_TYPE_ARP           0x0806
  #define ETH_TYPE_VLAN          0x8100
  #define ETH_TYPE_IPV6          0x86dd
  #define ETH_TYPE_LACP          0x8809
  
  /* Minimum value for an Ethernet type.  Values below this are IEEE 802.2 frame
   * lengths. */
  #define ETH_TYPE_MIN           0x600
  
  #define ETH_HEADER_LEN 14
  #define ETH_PAYLOAD_MIN 46
  #define ETH_PAYLOAD_MAX 1500
  #define ETH_TOTAL_MIN (ETH_HEADER_LEN + ETH_PAYLOAD_MIN)
  #define ETH_TOTAL_MAX (ETH_HEADER_LEN + ETH_PAYLOAD_MAX)
  #define ETH_VLAN_TOTAL_MAX (ETH_HEADER_LEN + VLAN_HEADER_LEN + ETH_PAYLOAD_MAX)
  struct eth_header {
      uint8_t eth_dst[ETH_ADDR_LEN];
      uint8_t eth_src[ETH_ADDR_LEN];
      ovs_be16 eth_type;
  } __attribute__((packed));
  BUILD_ASSERT_DECL(ETH_HEADER_LEN == sizeof(struct eth_header));
  
  #define LLC_DSAP_SNAP 0xaa
  #define LLC_SSAP_SNAP 0xaa
  #define LLC_CNTL_SNAP 3
  
  #define LLC_HEADER_LEN 3
  struct llc_header {
      uint8_t llc_dsap;
      uint8_t llc_ssap;
      uint8_t llc_cntl;
  } __attribute__((packed));
  BUILD_ASSERT_DECL(LLC_HEADER_LEN == sizeof(struct llc_header));
  
  #define SNAP_ORG_ETHERNET "\0\0" /* The compiler adds a null byte, so
                                      sizeof(SNAP_ORG_ETHERNET) == 3. */
  #define SNAP_HEADER_LEN 5
  struct snap_header {
      uint8_t snap_org[3];
      ovs_be16 snap_type;
  } __attribute__((packed));
  BUILD_ASSERT_DECL(SNAP_HEADER_LEN == sizeof(struct snap_header));
  
  #define LLC_SNAP_HEADER_LEN (LLC_HEADER_LEN + SNAP_HEADER_LEN)
  struct llc_snap_header {
      struct llc_header llc;
      struct snap_header snap;
  } __attribute__((packed));
  BUILD_ASSERT_DECL(LLC_SNAP_HEADER_LEN == sizeof(struct llc_snap_header));
  
  #define VLAN_VID_MASK 0x0fff
  #define VLAN_VID_SHIFT 0
  
  #define VLAN_PCP_MASK 0xe000
  #define VLAN_PCP_SHIFT 13
  
  #define VLAN_CFI 0x1000
  
  /* Given the vlan_tci field from an 802.1Q header, in network byte order,
   * returns the VLAN ID in host byte order. */
  static inline uint16_t
  vlan_tci_to_vid(ovs_be16 vlan_tci)
  {
      return (ntohs(vlan_tci) & VLAN_VID_MASK) >> VLAN_VID_SHIFT;
  }
  
  /* Given the vlan_tci field from an 802.1Q header, in network byte order,
   * returns the priority code point (PCP) in host byte order. */
  static inline int
  vlan_tci_to_pcp(ovs_be16 vlan_tci)
  {
      return (ntohs(vlan_tci) & VLAN_PCP_MASK) >> VLAN_PCP_SHIFT;
  }
  
  #define VLAN_HEADER_LEN 4
  struct vlan_header {
      ovs_be16 vlan_tci;          /* Lowest 12 bits are VLAN ID. */
      ovs_be16 vlan_next_type;
  };
  BUILD_ASSERT_DECL(VLAN_HEADER_LEN == sizeof(struct vlan_header));
  
  #define VLAN_ETH_HEADER_LEN (ETH_HEADER_LEN + VLAN_HEADER_LEN)
  struct vlan_eth_header {
      uint8_t veth_dst[ETH_ADDR_LEN];
      uint8_t veth_src[ETH_ADDR_LEN];
      ovs_be16 veth_type;         /* Always htons(ETH_TYPE_VLAN). */
      ovs_be16 veth_tci;          /* Lowest 12 bits are VLAN ID. */
      ovs_be16 veth_next_type;
  } __attribute__((packed));
  BUILD_ASSERT_DECL(VLAN_ETH_HEADER_LEN == sizeof(struct vlan_eth_header));
  
  /* The "(void) (ip)[0]" below has no effect on the value, since it's the first
   * argument of a comma expression, but it makes sure that 'ip' is a pointer.
   * This is useful since a common mistake is to pass an integer instead of a
   * pointer to IP_ARGS. */
  #define IP_FMT "%"PRIu8".%"PRIu8".%"PRIu8".%"PRIu8
  #define IP_ARGS(ip)                             \
          ((void) (ip)[0], ((uint8_t *) ip)[0]),  \
          ((uint8_t *) ip)[1],                    \
          ((uint8_t *) ip)[2],                    \
          ((uint8_t *) ip)[3]
  
  /* Returns true if 'netmask' is a CIDR netmask, that is, if it consists of N
   * high-order 1-bits and 32-N low-order 0-bits. */
  static inline bool
  ip_is_cidr(ovs_be32 netmask)
  {
      uint32_t x = ~ntohl(netmask);
      return !(x & (x + 1));
  }
  
  #define IP_VER(ip_ihl_ver) ((ip_ihl_ver) >> 4)
  #define IP_IHL(ip_ihl_ver) ((ip_ihl_ver) & 15)
  #define IP_IHL_VER(ihl, ver) (((ver) << 4) | (ihl))
  
  /* TOS fields. */
  #define IP_ECN_MASK 0x03
  #define IP_DSCP_MASK 0xfc
  
  #define IP_VERSION 4
  
  #define IP_DONT_FRAGMENT  0x4000 /* Don't fragment. */
  #define IP_MORE_FRAGMENTS 0x2000 /* More fragments. */
  #define IP_FRAG_OFF_MASK  0x1fff /* Fragment offset. */
  #define IP_IS_FRAGMENT(ip_frag_off) \
          ((ip_frag_off) & htons(IP_MORE_FRAGMENTS | IP_FRAG_OFF_MASK))
  
  #define IP_HEADER_LEN 20
  struct ip_header {
      uint8_t ip_ihl_ver;
      uint8_t ip_tos;
      ovs_be16 ip_tot_len;
      ovs_be16 ip_id;
      ovs_be16 ip_frag_off;
      uint8_t ip_ttl;
      uint8_t ip_proto;
      ovs_be16 ip_csum;
      ovs_be32 ip_src;
      ovs_be32 ip_dst;
  };
  BUILD_ASSERT_DECL(IP_HEADER_LEN == sizeof(struct ip_header));
  
  #define ICMP_HEADER_LEN 4
  struct icmp_header {
      uint8_t icmp_type;
      uint8_t icmp_code;
      ovs_be16 icmp_csum;
  };
  BUILD_ASSERT_DECL(ICMP_HEADER_LEN == sizeof(struct icmp_header));
  
  #define UDP_HEADER_LEN 8
  struct udp_header {
      ovs_be16 udp_src;
      ovs_be16 udp_dst;
      ovs_be16 udp_len;
      ovs_be16 udp_csum;
  };
  BUILD_ASSERT_DECL(UDP_HEADER_LEN == sizeof(struct udp_header));
  
  #define TCP_FIN 0x01
  #define TCP_SYN 0x02
  #define TCP_RST 0x04
  #define TCP_PSH 0x08
  #define TCP_ACK 0x10
  #define TCP_URG 0x20
  
  #define TCP_FLAGS(tcp_ctl) (htons(tcp_ctl) & 0x003f)
  #define TCP_OFFSET(tcp_ctl) (htons(tcp_ctl) >> 12)
  
  #define TCP_HEADER_LEN 20
  struct tcp_header {
      ovs_be16 tcp_src;
      ovs_be16 tcp_dst;
      ovs_be32 tcp_seq;
      ovs_be32 tcp_ack;
      ovs_be16 tcp_ctl;
      ovs_be16 tcp_winsz;
      ovs_be16 tcp_csum;
      ovs_be16 tcp_urg;
  };
  BUILD_ASSERT_DECL(TCP_HEADER_LEN == sizeof(struct tcp_header));
  
  #define ARP_HRD_ETHERNET 1
  #define ARP_PRO_IP 0x0800
  #define ARP_OP_REQUEST 1
  #define ARP_OP_REPLY 2
  
  #define ARP_ETH_HEADER_LEN 28
  struct arp_eth_header {
      /* Generic members. */
      ovs_be16 ar_hrd;           /* Hardware type. */
      ovs_be16 ar_pro;           /* Protocol type. */
      uint8_t ar_hln;            /* Hardware address length. */
      uint8_t ar_pln;            /* Protocol address length. */
      ovs_be16 ar_op;            /* Opcode. */
  
      /* Ethernet+IPv4 specific members. */
      uint8_t ar_sha[ETH_ADDR_LEN]; /* Sender hardware address. */
      ovs_be32 ar_spa;           /* Sender protocol address. */
      uint8_t ar_tha[ETH_ADDR_LEN]; /* Target hardware address. */
      ovs_be32 ar_tpa;           /* Target protocol address. */
  } __attribute__((packed));
  BUILD_ASSERT_DECL(ARP_ETH_HEADER_LEN == sizeof(struct arp_eth_header));
  
  extern const struct in6_addr in6addr_exact;
  #define IN6ADDR_EXACT_INIT { { { 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff, \
                                   0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff } } }
  
  static inline bool ipv6_addr_equals(const struct in6_addr *a,
                                      const struct in6_addr *b)
  {
  #ifdef IN6_ARE_ADDR_EQUAL
      return IN6_ARE_ADDR_EQUAL(a, b);
  #else
      return !memcmp(a, b, sizeof(*a));
  #endif
  }
  
  static inline bool ipv6_mask_is_any(const struct in6_addr *mask) {
      return ipv6_addr_equals(mask, &in6addr_any);
  }
  
  static inline bool ipv6_mask_is_exact(const struct in6_addr *mask) {
      return ipv6_addr_equals(mask, &in6addr_exact);
  }
  
  void format_ipv6_addr(char *addr_str, const struct in6_addr *addr);
  void print_ipv6_addr(struct ds *string, const struct in6_addr *addr);
  struct in6_addr ipv6_addr_bitand(const struct in6_addr *src,
                                   const struct in6_addr *mask);
  struct in6_addr ipv6_create_mask(int mask);
  int ipv6_count_cidr_bits(const struct in6_addr *netmask);
  bool ipv6_is_cidr(const struct in6_addr *netmask);
  
  void *
  compose_packet(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
                 const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
                 size_t size);
  
  /* Masks for lacp_info state member. */
  #define LACP_STATE_ACT  0x01 /* Activity. Active or passive? */
  #define LACP_STATE_TIME 0x02 /* Timeout. Short or long timeout? */
  #define LACP_STATE_AGG  0x04 /* Aggregation. Is the link is bondable? */
  #define LACP_STATE_SYNC 0x08 /* Synchronization. Is the link in up to date? */
  #define LACP_STATE_COL  0x10 /* Collecting. Is the link receiving frames? */
  #define LACP_STATE_DIST 0x20 /* Distributing. Is the link sending frames? */
  #define LACP_STATE_DEF  0x40 /* Defaulted. Using default partner info? */
  #define LACP_STATE_EXP  0x80 /* Expired. Using expired partner info? */
  
  #define LACP_FAST_TIME_TX 1000  /* Fast transmission rate. */
  #define LACP_SLOW_TIME_TX 30000 /* Slow transmission rate. */
  #define LACP_FAST_TIME_RX (LACP_FAST_TIME_TX * 3) /* Fast receive rate. */
  #define LACP_SLOW_TIME_RX (LACP_SLOW_TIME_TX * 3) /* Slow receive rate. */
  
  #define LACP_INFO_LEN 15
  struct lacp_info {
      ovs_be16 sys_priority;            /* System priority. */
      uint8_t sys_id[ETH_ADDR_LEN];     /* System ID. */
      ovs_be16 key;                     /* Operational key. */
      ovs_be16 port_priority;           /* Port priority. */
      ovs_be16 port_id;                 /* Port ID. */
      uint8_t state;                    /* State mask.  See LACP_STATE macros. */
  } __attribute__((packed));
  BUILD_ASSERT_DECL(LACP_INFO_LEN == sizeof(struct lacp_info));
  
  #define LACP_PDU_LEN 110
  struct lacp_pdu {
      uint8_t subtype;          /* Always 1. */
      uint8_t version;          /* Always 1. */
  
      uint8_t actor_type;       /* Always 1. */
      uint8_t actor_len;        /* Always 20. */
      struct lacp_info actor;   /* LACP actor information. */
      uint8_t z1[3];            /* Reserved.  Always 0. */
  
      uint8_t partner_type;     /* Always 2. */
      uint8_t partner_len;      /* Always 20. */
      struct lacp_info partner; /* LACP partner information. */
      uint8_t z2[3];            /* Reserved.  Always 0. */
  
      uint8_t collector_type;   /* Always 3. */
      uint8_t collector_len;    /* Always 16. */
      ovs_be16 collector_delay; /* Maximum collector delay. Set to UINT16_MAX. */
      uint8_t z3[64];           /* Combination of several fields.  Always 0. */
  } __attribute__((packed));
  BUILD_ASSERT_DECL(LACP_PDU_LEN == sizeof(struct lacp_pdu));
  
  void compose_lacp_pdu(const struct lacp_info *actor,
                        const struct lacp_info *partner, struct lacp_pdu *);
  
  const struct lacp_pdu *parse_lacp_packet(const struct ofpbuf *);
  
  #endif /* packets.h */
  