bgp.h

   1 /* BGPv4 (RFC1771) */
   2 /* $Id: bgp.h,v 1.2 2004-06-28 02:43:13 fred_nerk 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_MAX_RETRY           42      /* maximum number of times to retry */
  11 #define BGP_RETRY_BACKOFF       60      /* number of seconds between retries,
  12                                            cumulative */
  13
  14 #define BGP_METRIC              1       /* multi_exit_disc */
  15 #define BGP_LOCAL_PREF          100     /* local preference value */
  16
  17 struct bgp_header {
  18     char marker[16];
  19     u16 len;
  20     u8 type;
  21 } __attribute__ ((packed));
  22
  23 /* bgp_header.type */
  24 #define BGP_MSG_OPEN            1
  25 #define BGP_MSG_UPDATE          2
  26 #define BGP_MSG_NOTIFICATION    3
  27 #define BGP_MSG_KEEPALIVE       4
  28
  29 struct bgp_packet {
  30     struct bgp_header header;
  31     char data[BGP_MAX_PACKET_SIZE - sizeof(struct bgp_header)]; /* variable */
  32 } __attribute__ ((packed));
  33
  34 struct bgp_data_open {
  35     u8 version;
  36 #define BGP_VERSION     4
  37     u16 as;
  38     u16 hold_time;
  39     u32 identifier;
  40     u8 opt_len;
  41 #define BGP_DATA_OPEN_SIZE      10 /* size of struct excluding opt_params */
  42     char opt_params[sizeof(((struct bgp_packet *)0)->data) - BGP_DATA_OPEN_SIZE]; /* variable */
  43 } __attribute__ ((packed));
  44
  45 struct bgp_ip_prefix {
  46     u8 len;
  47     u32 prefix; /* variable */
  48 } __attribute__ ((packed));
  49
  50 #define BGP_IP_PREFIX_SIZE(p) (1 + ((p).len / 8) + ((p).len % 8 != 0))
  51
  52 struct bgp_path_attr {
  53     u8 flags;
  54     u8 code;
  55     union {
  56         struct {
  57             u8 len;
  58             char value[29];             /* semi-random size, adequate for l2tpns */
  59         } __attribute__ ((packed)) s;   /* short */
  60         struct {
  61             u16 len;
  62             char value[28];
  63         } __attribute__ ((packed)) e;   /* extended */
  64     } data; /* variable */
  65 } __attribute__ ((packed));
  66
  67 /* bgp_path_attr.flags (bitfields) */
  68 #define BGP_PATH_ATTR_FLAG_OPTIONAL     (1 << 7)
  69 #define BGP_PATH_ATTR_FLAG_TRANS        (1 << 6)
  70 #define BGP_PATH_ATTR_FLAG_PARTIAL      (1 << 5)
  71 #define BGP_PATH_ATTR_FLAG_EXTLEN       (1 << 4)
  72
  73 /* bgp_path_attr.code, ...value */
  74 #define BGP_PATH_ATTR_CODE_ORIGIN               1       /* well-known, mandatory */
  75 #  define BGP_PATH_ATTR_CODE_ORIGIN_IGP           0
  76 #  define BGP_PATH_ATTR_CODE_ORIGIN_EGP           1
  77 #  define BGP_PATH_ATTR_CODE_ORIGIN_INCOMPLETE    2
  78 #define BGP_PATH_ATTR_CODE_AS_PATH              2       /* well-known, mandatory */
  79 #  define BGP_PATH_ATTR_CODE_AS_PATH_AS_SET       1
  80 #  define BGP_PATH_ATTR_CODE_AS_PATH_AS_SEQUENCE  2
  81 #define BGP_PATH_ATTR_CODE_NEXT_HOP             3       /* well-known, mandatory */
  82 #define BGP_PATH_ATTR_CODE_MULTI_EXIT_DISC      4       /* optional, non-transitive */
  83 #define BGP_PATH_ATTR_CODE_LOCAL_PREF           5       /* well-known, discretionary */
  84 #define BGP_PATH_ATTR_CODE_ATOMIC_AGGREGATE     6       /* well-known, discretionary */
  85 #define BGP_PATH_ATTR_CODE_AGGREGATOR           7       /* optional, transitive */
  86 #define BGP_PATH_ATTR_CODE_COMMUNITIES          8       /* optional, transitive (RFC1997) */
  87
  88 #define BGP_PATH_ATTR_SIZE(p) ((((p).flags & BGP_PATH_ATTR_FLAG_EXTLEN) \
  89     ? ((p).data.e.len + 1) : (p).data.s.len) + 3)
  90
  91 /* well known COMMUNITIES */
  92 #define BGP_COMMUNITY_NO_EXPORT                 0xffffff01      /* don't advertise outside confederation */
  93 #define BGP_COMMUNITY_NO_ADVERTISE              0xffffff02      /* don't advertise to any peer */
  94 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED       0xffffff03      /* don't advertise to any other AS */
  95
  96 struct bgp_data_notification {
  97     u8 error_code;
  98     u8 error_subcode;
  99     char data[sizeof(((struct bgp_packet *)0)->data) - 2]; /* variable */
 100 } __attribute__ ((packed));
 101
 102 /* bgp_data_notification.error_code, .error_subcode */
 103 #define BGP_ERR_HEADER                  1
 104 #  define BGP_ERR_HDR_NOT_SYNC            1
 105 #  define BGP_ERR_HDR_BAD_LEN             2
 106 #  define BGP_ERR_HDR_BAD_TYPE            3
 107 #define BGP_ERR_OPEN                    2
 108 #  define BGP_ERR_OPN_VERSION             1
 109 #  define BGP_ERR_OPN_BAD_AS              2
 110 #  define BGP_ERR_OPN_BAD_IDENT           3
 111 #  define BGP_ERR_OPN_UNSUP_PARAM         4
 112 #  define BGP_ERR_OPN_AUTH_FAILURE        5
 113 #  define BGP_ERR_OPN_HOLD_TIME           6
 114 #define BGP_ERR_UPDATE                  3
 115 #  define BGP_ERR_UPD_BAD_ATTR_LIST       1
 116 #  define BGP_ERR_UPD_UNKN_WK_ATTR        2
 117 #  define BGP_ERR_UPD_MISS_WK_ATTR        3
 118 #  define BGP_ERR_UPD_BAD_ATTR_FLAG       4
 119 #  define BGP_ERR_UPD_BAD_ATTR_LEN        5
 120 #  define BGP_ERR_UPD_BAD_ORIGIN          6
 121 #  define BGP_ERR_UPD_ROUTING_LOOP        7
 122 #  define BGP_ERR_UPD_BAD_NEXT_HOP        8
 123 #  define BGP_ERR_UPD_BAD_OPT_ATTR        9
 124 #  define BGP_ERR_UPD_BAD_NETWORK         10
 125 #  define BGP_ERR_UPD_BAD_AS_PATH         11
 126 #define BGP_ERR_HOLD_TIMER_EXP          4
 127 #define BGP_ERR_FSM                     5
 128 #define BGP_ERR_CEASE                   6
 129
 130 enum bgp_state {
 131     Disabled,                           /* initial, or failed */
 132     Idle,                               /* trying to connect */
 133     Connect,                            /* connect issued */
 134     Active,                             /* connected, waiting to send OPEN */
 135     OpenSent,                           /* OPEN sent, waiting for peer OPEN */
 136     OpenConfirm,                        /* KEEPALIVE sent, waiting for peer KEEPALIVE */
 137     Established,                        /* established */
 138 };
 139
 140 struct bgp_route_list {
 141     struct bgp_ip_prefix dest;
 142     struct bgp_route_list *next;
 143 };
 144
 145 struct bgp_buf {
 146     struct bgp_packet packet;           /* BGP packet */
 147     size_t done;                        /* bytes sent/recvd */
 148 };
 149
 150 /* state */
 151 struct bgp_peer {
 152     char name[32];                      /* peer name */
 153     in_addr_t addr;                     /* peer address */
 154     int as;                             /* AS number */
 155     int sock;
 156     enum bgp_state state;               /* FSM state */
 157     enum bgp_state next_state;          /* next state after outbuf cleared */
 158     time_t state_time;                  /* time of last state change */
 159     time_t keepalive_time;              /* time to send next keepalive */
 160     time_t retry_time;                  /* time for connection retry */
 161     int retry_count;                    /* connection retry count */
 162     int hold;                           /* hold time from peer */
 163     time_t expire_time;                 /* time next peer packet expected */
 164     int routing;                        /* propagate routes */
 165     int update_routes;                  /* UPDATE required */
 166     struct bgp_route_list *routes;      /* routes known by this peer */
 167     struct bgp_buf *outbuf;             /* pending output */
 168     struct bgp_buf *inbuf;              /* pending input */
 169     int cli_flag;                       /* updates requested from CLI */
 170     char *path_attrs;                   /* path attrs to send in UPDATE message */
 171     int path_attr_len;                  /* length of path attrs */
 172 };
 173
 174 /* bgp_peer.cli_flag */
 175 #define BGP_CLI_SUSPEND         1
 176 #define BGP_CLI_ENABLE          2
 177 #define BGP_CLI_RESTART         3
 178
 179 #define BGP_NUM_PEERS 2
 180 extern struct bgp_peer *bgp_peers;
 181 extern struct bgp_route_list *bgp_routes;
 182 extern int bgp_configured;
 183
 184 /* actions */
 185 int bgp_setup(int as);
 186 int bgp_start(struct bgp_peer *peer, char *name, int as, int enable);
 187 void bgp_stop(struct bgp_peer *peer);
 188 void bgp_halt(struct bgp_peer *peer);
 189 int bgp_restart(struct bgp_peer *peer);
 190 int bgp_add_route(in_addr_t ip, in_addr_t mask);
 191 int bgp_del_route(in_addr_t ip, in_addr_t mask);
 192 void bgp_enable_routing(int enable);
 193 int bgp_select_state(struct bgp_peer *peer);
 194 int bgp_process(struct bgp_peer *peer, int readable, int writable);
 195
 196 /* CLI */
 197 int cmd_show_bgp(struct cli_def *cli, char *command, char **argv, int argc);
 198 int cmd_suspend_bgp(struct cli_def *cli, char *command, char **argv, int argc);
 199 int cmd_no_suspend_bgp(struct cli_def *cli, char *command, char **argv, int argc);
 200 int cmd_restart_bgp(struct cli_def *cli, char *command, char **argv, int argc);
 201
 202 extern char const *cvs_id_bgp;
 203
 204 #endif /* __BGP_H__ */