bgp.h

   1 /* BGPv4 (RFC1771) */
   2 /* $Id: bgp.h,v 1.4 2004/12/16 08:49:52 bodea Exp $ */
   3
   4 #ifndef __BGP_H__
   5 #define __BGP_H__
   6
   7 #define BGP_MAX_PACKET_SIZE     4096
   8 #define BGP_HOLD_TIME           180     /* seconds before peer times us out */
   9 #define BGP_KEEPALIVE_TIME      60      /* seconds between messages */
  10 #define BGP_STATE_TIME          60      /* state transition timeout in seconds */
  11 #define BGP_MAX_RETRY           42      /* maximum number of times to retry */
  12 #define BGP_RETRY_BACKOFF       60      /* number of seconds between retries,
  13                                            cumulative */
  14
  15 #define BGP_METRIC              1       /* multi_exit_disc */
  16 #define BGP_LOCAL_PREF          100     /* local preference value */
  17
  18 struct bgp_header {
  19     char marker[16];
  20     uint16_t len;
  21     uint8_t type;
  22 } __attribute__ ((packed));
  23
  24 /* bgp_header.type */
  25 #define BGP_MSG_OPEN            1
  26 #define BGP_MSG_UPDATE          2
  27 #define BGP_MSG_NOTIFICATION    3
  28 #define BGP_MSG_KEEPALIVE       4
  29
  30 struct bgp_packet {
  31     struct bgp_header header;
  32     char data[BGP_MAX_PACKET_SIZE - sizeof(struct bgp_header)]; /* variable */
  33 } __attribute__ ((packed));
  34
  35 struct bgp_data_open {
  36     uint8_t version;
  37 #define BGP_VERSION     4
  38     uint16_t as;
  39     uint16_t hold_time;
  40     uint32_t identifier;
  41     uint8_t opt_len;
  42 #define BGP_DATA_OPEN_SIZE      10 /* size of struct excluding opt_params */
  43     char opt_params[sizeof(((struct bgp_packet *)0)->data) - BGP_DATA_OPEN_SIZE]; /* variable */
  44 } __attribute__ ((packed));
  45
  46 struct bgp_ip_prefix {
  47     uint8_t len;
  48     uint32_t prefix; /* variable */
  49 } __attribute__ ((packed));
  50
  51 #define BGP_IP_PREFIX_SIZE(p) (1 + ((p).len / 8) + ((p).len % 8 != 0))
  52
  53 struct bgp_path_attr {
  54     uint8_t flags;
  55     uint8_t code;
  56     union {
  57         struct {
  58             uint8_t len;
  59             char value[29];             /* semi-random size, adequate for l2tpns */
  60         } __attribute__ ((packed)) s;   /* short */
  61         struct {
  62             uint16_t len;
  63             char value[28];
  64         } __attribute__ ((packed)) e;   /* extended */
  65     } data; /* variable */
  66 } __attribute__ ((packed));
  67
  68 /* bgp_path_attr.flags (bitfields) */
  69 #define BGP_PATH_ATTR_FLAG_OPTIONAL     (1 << 7)
  70 #define BGP_PATH_ATTR_FLAG_TRANS        (1 << 6)
  71 #define BGP_PATH_ATTR_FLAG_PARTIAL      (1 << 5)
  72 #define BGP_PATH_ATTR_FLAG_EXTLEN       (1 << 4)
  73
  74 /* bgp_path_attr.code, ...value */
  75 #define BGP_PATH_ATTR_CODE_ORIGIN               1       /* well-known, mandatory */
  76 #  define BGP_PATH_ATTR_CODE_ORIGIN_IGP           0
  77 #  define BGP_PATH_ATTR_CODE_ORIGIN_EGP           1
  78 #  define BGP_PATH_ATTR_CODE_ORIGIN_INCOMPLETE    2
  79 #define BGP_PATH_ATTR_CODE_AS_PATH              2       /* well-known, mandatory */
  80 #  define BGP_PATH_ATTR_CODE_AS_PATH_AS_SET       1
  81 #  define BGP_PATH_ATTR_CODE_AS_PATH_AS_SEQUENCE  2
  82 #define BGP_PATH_ATTR_CODE_NEXT_HOP             3       /* well-known, mandatory */
  83 #define BGP_PATH_ATTR_CODE_MULTI_EXIT_DISC      4       /* optional, non-transitive */
  84 #define BGP_PATH_ATTR_CODE_LOCAL_PREF           5       /* well-known, discretionary */
  85 #define BGP_PATH_ATTR_CODE_ATOMIC_AGGREGATE     6       /* well-known, discretionary */
  86 #define BGP_PATH_ATTR_CODE_AGGREGATOR           7       /* optional, transitive */
  87 #define BGP_PATH_ATTR_CODE_COMMUNITIES          8       /* optional, transitive (RFC1997) */
  88
  89 #define BGP_PATH_ATTR_SIZE(p) ((((p).flags & BGP_PATH_ATTR_FLAG_EXTLEN) \
  90     ? ((p).data.e.len + 1) : (p).data.s.len) + 3)
  91
  92 /* well known COMMUNITIES */
  93 #define BGP_COMMUNITY_NO_EXPORT                 0xffffff01      /* don't advertise outside confederation */
  94 #define BGP_COMMUNITY_NO_ADVERTISE              0xffffff02      /* don't advertise to any peer */
  95 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED       0xffffff03      /* don't advertise to any other AS */
  96
  97 struct bgp_data_notification {
  98     uint8_t error_code;
  99     uint8_t error_subcode;
 100     char data[sizeof(((struct bgp_packet *)0)->data) - 2]; /* variable */
 101 } __attribute__ ((packed));
 102
 103 /* bgp_data_notification.error_code, .error_subcode */
 104 #define BGP_ERR_HEADER                  1
 105 #  define BGP_ERR_HDR_NOT_SYNC            1
 106 #  define BGP_ERR_HDR_BAD_LEN             2
 107 #  define BGP_ERR_HDR_BAD_TYPE            3
 108 #define BGP_ERR_OPEN                    2
 109 #  define BGP_ERR_OPN_VERSION             1
 110 #  define BGP_ERR_OPN_BAD_AS              2
 111 #  define BGP_ERR_OPN_BAD_IDENT           3
 112 #  define BGP_ERR_OPN_UNSUP_PARAM         4
 113 #  define BGP_ERR_OPN_AUTH_FAILURE        5
 114 #  define BGP_ERR_OPN_HOLD_TIME           6
 115 #define BGP_ERR_UPDATE                  3
 116 #  define BGP_ERR_UPD_BAD_ATTR_LIST       1
 117 #  define BGP_ERR_UPD_UNKN_WK_ATTR        2
 118 #  define BGP_ERR_UPD_MISS_WK_ATTR        3
 119 #  define BGP_ERR_UPD_BAD_ATTR_FLAG       4
 120 #  define BGP_ERR_UPD_BAD_ATTR_LEN        5
 121 #  define BGP_ERR_UPD_BAD_ORIGIN          6
 122 #  define BGP_ERR_UPD_ROUTING_LOOP        7
 123 #  define BGP_ERR_UPD_BAD_NEXT_HOP        8
 124 #  define BGP_ERR_UPD_BAD_OPT_ATTR        9
 125 #  define BGP_ERR_UPD_BAD_NETWORK         10
 126 #  define BGP_ERR_UPD_BAD_AS_PATH         11
 127 #define BGP_ERR_HOLD_TIMER_EXP          4
 128 #define BGP_ERR_FSM                     5
 129 #define BGP_ERR_CEASE                   6
 130
 131 enum bgp_state {
 132     Disabled,                           /* initial, or failed */
 133     Idle,                               /* trying to connect */
 134     Connect,                            /* connect issued */
 135     Active,                             /* connected, waiting to send OPEN */
 136     OpenSent,                           /* OPEN sent, waiting for peer OPEN */
 137     OpenConfirm,                        /* KEEPALIVE sent, waiting for peer KEEPALIVE */
 138     Established,                        /* established */
 139 };
 140
 141 struct bgp_route_list {
 142     struct bgp_ip_prefix dest;
 143     struct bgp_route_list *next;
 144 };
 145
 146 struct bgp_buf {
 147     struct bgp_packet packet;           /* BGP packet */
 148     size_t done;                        /* bytes sent/recvd */
 149 };
 150
 151 /* state */
 152 struct bgp_peer {
 153     char name[32];                      /* peer name */
 154     in_addr_t addr;                     /* peer address */
 155     int as;                             /* AS number */
 156     int sock;
 157     enum bgp_state state;               /* FSM state */
 158     enum bgp_state next_state;          /* next state after outbuf cleared */
 159     time_t state_time;                  /* time of last state change */
 160     time_t keepalive_time;              /* time to send next keepalive */
 161     time_t retry_time;                  /* time for connection retry */
 162     int retry_count;                    /* connection retry count */
 163     int init_keepalive;                 /* initial keepalive time */
 164     int init_hold;                      /* initial hold time */
 165     int keepalive;                      /* negotiated keepalive time */
 166     int hold;                           /* negotiated hold time */
 167     time_t expire_time;                 /* time next peer packet expected */
 168     int routing;                        /* propagate routes */
 169     int update_routes;                  /* UPDATE required */
 170     struct bgp_route_list *routes;      /* routes known by this peer */
 171     struct bgp_buf *outbuf;             /* pending output */
 172     struct bgp_buf *inbuf;              /* pending input */
 173     int cli_flag;                       /* updates requested from CLI */
 174     char *path_attrs;                   /* path attrs to send in UPDATE message */
 175     int path_attr_len;                  /* length of path attrs */
 176 };
 177
 178 /* bgp_peer.cli_flag */
 179 #define BGP_CLI_SUSPEND         1
 180 #define BGP_CLI_ENABLE          2
 181 #define BGP_CLI_RESTART         3
 182
 183 extern struct bgp_peer *bgp_peers;
 184 extern int bgp_configured;
 185
 186 /* actions */
 187 int bgp_setup(int as);
 188 int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
 189     int hold, int enable);
 190
 191 void bgp_stop(struct bgp_peer *peer);
 192 void bgp_halt(struct bgp_peer *peer);
 193 int bgp_restart(struct bgp_peer *peer);
 194 int bgp_add_route(in_addr_t ip, in_addr_t mask);
 195 int bgp_del_route(in_addr_t ip, in_addr_t mask);
 196 void bgp_enable_routing(int enable);
 197 int bgp_select_state(struct bgp_peer *peer);
 198 int bgp_process(struct bgp_peer *peer, int readable, int writable);
 199 char const *bgp_state_str(enum bgp_state state);
 200
 201 extern char const *cvs_id_bgp;
 202
 203 #endif /* __BGP_H__ */