bgp.h

   1 /* BGPv4 (RFC1771) */
   2 /* $Id: bgp.h,v 1.5 2005/06/04 15:42:35 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_opt_param {
  47     uint8_t type;
  48     uint8_t len;
  49 #define BGP_MAX_OPT_PARAM_SIZE 256
  50     char value[BGP_MAX_OPT_PARAM_SIZE];
  51 } __attribute__ ((packed));
  52
  53 #define BGP_CAPABILITY_PARAM_TYPE 2
  54 struct bgp_capability {
  55     uint8_t code;
  56     uint8_t len;
  57 #define BGP_MAX_CAPABILITY_SIZE 256
  58     char value[BGP_MAX_CAPABILITY_SIZE];
  59 } __attribute__ ((packed));
  60
  61 struct bgp_ip_prefix {
  62     uint8_t len;
  63     uint32_t prefix; /* variable */
  64 } __attribute__ ((packed));
  65
  66 #define BGP_IP_PREFIX_SIZE(p) (1 + ((p).len / 8) + ((p).len % 8 != 0))
  67
  68 struct bgp_path_attr {
  69     uint8_t flags;
  70     uint8_t code;
  71     union {
  72         struct {
  73             uint8_t len;
  74             char value[29];             /* semi-random size, adequate for l2tpns */
  75         } __attribute__ ((packed)) s;   /* short */
  76         struct {
  77             uint16_t len;
  78             char value[28];
  79         } __attribute__ ((packed)) e;   /* extended */
  80     } data; /* variable */
  81 } __attribute__ ((packed));
  82
  83 /* bgp_path_attr.flags (bitfields) */
  84 #define BGP_PATH_ATTR_FLAG_OPTIONAL     (1 << 7)
  85 #define BGP_PATH_ATTR_FLAG_TRANS        (1 << 6)
  86 #define BGP_PATH_ATTR_FLAG_PARTIAL      (1 << 5)
  87 #define BGP_PATH_ATTR_FLAG_EXTLEN       (1 << 4)
  88
  89 /* bgp_path_attr.code, ...value */
  90 #define BGP_PATH_ATTR_CODE_ORIGIN               1       /* well-known, mandatory */
  91 #  define BGP_PATH_ATTR_CODE_ORIGIN_IGP           0
  92 #  define BGP_PATH_ATTR_CODE_ORIGIN_EGP           1
  93 #  define BGP_PATH_ATTR_CODE_ORIGIN_INCOMPLETE    2
  94 #define BGP_PATH_ATTR_CODE_AS_PATH              2       /* well-known, mandatory */
  95 #  define BGP_PATH_ATTR_CODE_AS_PATH_AS_SET       1
  96 #  define BGP_PATH_ATTR_CODE_AS_PATH_AS_SEQUENCE  2
  97 #define BGP_PATH_ATTR_CODE_NEXT_HOP             3       /* well-known, mandatory */
  98 #define BGP_PATH_ATTR_CODE_MULTI_EXIT_DISC      4       /* optional, non-transitive */
  99 #define BGP_PATH_ATTR_CODE_LOCAL_PREF           5       /* well-known, discretionary */
 100 #define BGP_PATH_ATTR_CODE_ATOMIC_AGGREGATE     6       /* well-known, discretionary */
 101 #define BGP_PATH_ATTR_CODE_AGGREGATOR           7       /* optional, transitive */
 102 #define BGP_PATH_ATTR_CODE_COMMUNITIES          8       /* optional, transitive (RFC1997) */
 103
 104 #define BGP_PATH_ATTR_SIZE(p) ((((p).flags & BGP_PATH_ATTR_FLAG_EXTLEN) \
 105     ? ((p).data.e.len + 1) : (p).data.s.len) + 3)
 106
 107 /* well known COMMUNITIES */
 108 #define BGP_COMMUNITY_NO_EXPORT                 0xffffff01      /* don't advertise outside confederation */
 109 #define BGP_COMMUNITY_NO_ADVERTISE              0xffffff02      /* don't advertise to any peer */
 110 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED       0xffffff03      /* don't advertise to any other AS */
 111
 112 struct bgp_data_notification {
 113     uint8_t error_code;
 114     uint8_t error_subcode;
 115     char data[sizeof(((struct bgp_packet *)0)->data) - 2]; /* variable */
 116 } __attribute__ ((packed));
 117
 118 /* bgp_data_notification.error_code, .error_subcode */
 119 #define BGP_ERR_UNSPEC                  0
 120 #define BGP_ERR_HEADER                  1
 121 #  define BGP_ERR_HDR_NOT_SYNC            1
 122 #  define BGP_ERR_HDR_BAD_LEN             2
 123 #  define BGP_ERR_HDR_BAD_TYPE            3
 124 #define BGP_ERR_OPEN                    2
 125 #  define BGP_ERR_OPN_VERSION             1
 126 #  define BGP_ERR_OPN_BAD_AS              2
 127 #  define BGP_ERR_OPN_BAD_IDENT           3
 128 #  define BGP_ERR_OPN_UNSUP_PARAM         4
 129 #  define BGP_ERR_OPN_AUTH_FAILURE        5
 130 #  define BGP_ERR_OPN_HOLD_TIME           6
 131 #  define BGP_ERR_OPN_UNSUP_CAP           7
 132 #define BGP_ERR_UPDATE                  3
 133 #  define BGP_ERR_UPD_BAD_ATTR_LIST       1
 134 #  define BGP_ERR_UPD_UNKN_WK_ATTR        2
 135 #  define BGP_ERR_UPD_MISS_WK_ATTR        3
 136 #  define BGP_ERR_UPD_BAD_ATTR_FLAG       4
 137 #  define BGP_ERR_UPD_BAD_ATTR_LEN        5
 138 #  define BGP_ERR_UPD_BAD_ORIGIN          6
 139 #  define BGP_ERR_UPD_ROUTING_LOOP        7
 140 #  define BGP_ERR_UPD_BAD_NEXT_HOP        8
 141 #  define BGP_ERR_UPD_BAD_OPT_ATTR        9
 142 #  define BGP_ERR_UPD_BAD_NETWORK         10
 143 #  define BGP_ERR_UPD_BAD_AS_PATH         11
 144 #define BGP_ERR_HOLD_TIMER_EXP          4
 145 #define BGP_ERR_FSM                     5
 146 #define BGP_ERR_CEASE                   6
 147
 148 enum bgp_state {
 149     Disabled,                           /* initial, or failed */
 150     Idle,                               /* trying to connect */
 151     Connect,                            /* connect issued */
 152     Active,                             /* connected, waiting to send OPEN */
 153     OpenSent,                           /* OPEN sent, waiting for peer OPEN */
 154     OpenConfirm,                        /* KEEPALIVE sent, waiting for peer KEEPALIVE */
 155     Established,                        /* established */
 156 };
 157
 158 struct bgp_route_list {
 159     struct bgp_ip_prefix dest;
 160     struct bgp_route_list *next;
 161 };
 162
 163 struct bgp_buf {
 164     struct bgp_packet packet;           /* BGP packet */
 165     size_t done;                        /* bytes sent/recvd */
 166 };
 167
 168 /* state */
 169 struct bgp_peer {
 170     char name[32];                      /* peer name */
 171     in_addr_t addr;                     /* peer address */
 172     int as;                             /* AS number */
 173     int sock;
 174     enum bgp_state state;               /* FSM state */
 175     enum bgp_state next_state;          /* next state after outbuf cleared */
 176     time_t state_time;                  /* time of last state change */
 177     time_t keepalive_time;              /* time to send next keepalive */
 178     time_t retry_time;                  /* time for connection retry */
 179     int retry_count;                    /* connection retry count */
 180     int init_keepalive;                 /* initial keepalive time */
 181     int init_hold;                      /* initial hold time */
 182     int keepalive;                      /* negotiated keepalive time */
 183     int hold;                           /* negotiated hold time */
 184     time_t expire_time;                 /* time next peer packet expected */
 185     int routing;                        /* propagate routes */
 186     int update_routes;                  /* UPDATE required */
 187     struct bgp_route_list *routes;      /* routes known by this peer */
 188     struct bgp_buf *outbuf;             /* pending output */
 189     struct bgp_buf *inbuf;              /* pending input */
 190     int cli_flag;                       /* updates requested from CLI */
 191     char *path_attrs;                   /* path attrs to send in UPDATE message */
 192     int path_attr_len;                  /* length of path attrs */
 193     uint32_t events;                    /* events to poll */
 194     struct event_data edata;            /* poll data */
 195 };
 196
 197 /* bgp_peer.cli_flag */
 198 #define BGP_CLI_SUSPEND         1
 199 #define BGP_CLI_ENABLE          2
 200 #define BGP_CLI_RESTART         3
 201
 202 extern struct bgp_peer *bgp_peers;
 203 extern int bgp_configured;
 204
 205 /* actions */
 206 int bgp_setup(int as);
 207 int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
 208     int hold, int enable);
 209
 210 void bgp_stop(struct bgp_peer *peer);
 211 void bgp_halt(struct bgp_peer *peer);
 212 int bgp_restart(struct bgp_peer *peer);
 213 int bgp_add_route(in_addr_t ip, in_addr_t mask);
 214 int bgp_del_route(in_addr_t ip, in_addr_t mask);
 215 void bgp_enable_routing(int enable);
 216 int bgp_set_poll(void);
 217 int bgp_process(uint32_t events[]);
 218 char const *bgp_state_str(enum bgp_state state);
 219
 220 extern char const *cvs_id_bgp;
 221
 222 #endif /* __BGP_H__ */