diff options
Diffstat (limited to 'usr.sbin/mrouted/dvmrp.h')
| -rw-r--r-- | usr.sbin/mrouted/dvmrp.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/usr.sbin/mrouted/dvmrp.h b/usr.sbin/mrouted/dvmrp.h new file mode 100644 index 000000000000..6928fe82bb9e --- /dev/null +++ b/usr.sbin/mrouted/dvmrp.h @@ -0,0 +1,141 @@ +/* + * The mrouted program is covered by the license in the accompanying file + * named "LICENSE". Use of the mrouted program represents acceptance of + * the terms and conditions listed in that file. + * + * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of + * Leland Stanford Junior University. + * + * + * $Id: dvmrp.h,v 1.1.1.1 1994/05/17 20:59:33 jkh Exp $ + */ + +/* + * A DVMRP message consists of an IP header + an IGMP header + (for some types) + * zero or more bytes of data. + * + * For REPORT messages, the data is route information; the route information + * consists of one or more lists of the following form: + * + * (mask, (origin, metric), (origin, metric), ...) + * + * where: + * + * "mask" is the subnet mask for all the origins in the list. + * It is always THREE bytes long, containing the low-order + * three bytes of the mask (the high-order byte is always + * 0xff and therefore need not be transmitted). + * + * "origin" is the number of a subnet from which multicast datagrams + * may originate. It is from one to four bytes long, + * depending on the value of "mask": + * if all bytes of the mask are zero + * the subnet number is one byte long + * else if the low-order two bytes of the mask are zero + * the subnet number is two bytes long + * else if the lowest-order byte of the mask is zero + * the subnet number is three bytes long, + * else + * the subnet number is four bytes long. + * + * "metric" is a one-byte value consisting of two subfields: + * - the high-order bit is a flag which, when set, indicates + * the last (origin, metric) pair of a list. + * - the low-order seven bits contain the routing metric for + * the corresponding origin, relative to the sender of the + * DVMRP report. The metric may have the value of UNREACHABLE + * added to it as a "split horizon" indication (so called + * "poisoned reverse"). + * + * Within a list, the origin subnet numbers must be in ascending order, and + * the lists themselves are in order of increasing mask value. A message may + * not exceed 576 bytes, the default maximum IP reassembly size, including + * the IP and IGMP headers; the route information may be split across more + * than one message if necessary, by terminating a list in one message and + * starting a new list in the next message (repeating the same mask value, + * if necessary). + * + * For NEIGHBORS messages, the data is neighboring-router information + * consisting of one or more lists of the following form: + * + * (local-addr, metric, threshold, ncount, neighbor, neighbor, ...) + * + * where: + * + * "local-addr" is the sending router's address as seen by the neighbors + * in this list; it is always four bytes long. + * "metric" is a one-byte unsigned value, the TTL `cost' of forwarding + * packets to any of the neighbors on this list. + * "threshold" is a one-byte unsigned value, a lower bound on the TTL a + * packet must have to be forwarded to any of the neighbors on + * this list. + * "ncount" is the number of neighbors in this list. + * "neighbor" is the address of a neighboring router, four bytes long. + * + * As with REPORT messages, NEIGHBORS messages should not exceed 576 bytes, + * including the IP and IGMP headers; split longer messages by terminating the + * list in one and continuing in another, repeating the local-addr, etc., if + * necessary. + * + * For NEIGHBORS2 messages, the data is identical to NEIGHBORS except + * there is a flags byte before the neighbor count: + * + * (local-addr, metric, threshold, flags, ncount, neighbor, neighbor, ...) + */ + +/* + * DVMRP message types (carried in the "code" field of an IGMP header) + */ +#define DVMRP_PROBE 1 /* for finding neighbors */ +#define DVMRP_REPORT 2 /* for reporting some or all routes */ +#define DVMRP_ASK_NEIGHBORS 3 /* sent by mapper, asking for a list */ + /* of this router's neighbors. */ +#define DVMRP_NEIGHBORS 4 /* response to such a request */ +#define DVMRP_ASK_NEIGHBORS2 5 /* as above, want new format reply */ +#define DVMRP_NEIGHBORS2 6 + +/* + * 'flags' byte values in DVMRP_NEIGHBORS2 reply. + */ +#define DVMRP_NF_TUNNEL 0x01 /* neighbors reached via tunnel */ +#define DVMRP_NF_SRCRT 0x02 /* tunnel uses IP source routing */ +#define DVMRP_NF_DOWN 0x10 /* kernel state of interface */ +#define DVMRP_NF_DISABLED 0x20 /* administratively disabled */ +#define DVMRP_NF_QUERIER 0x40 /* I am the subnet's querier */ + +/* + * Limit on length of route data + */ +#define MAX_IP_PACKET_LEN 576 +#define MIN_IP_HEADER_LEN 20 +#define MAX_IP_HEADER_LEN 60 +#define MAX_DVMRP_DATA_LEN \ + ( MAX_IP_PACKET_LEN - MAX_IP_HEADER_LEN - IGMP_MINLEN ) + +/* + * Various protocol constants (all times in seconds) + */ + /* address for multicast DVMRP msgs */ +#define INADDR_DVMRP_GROUP (u_long)0xe0000004 /* 224.0.0.4 */ + +#define ROUTE_MAX_REPORT_DELAY 5 /* max delay for reporting changes */ + /* (This is the timer interrupt */ + /* interval; all times must be */ + /* multiples of this value.) */ + +#define ROUTE_REPORT_INTERVAL 60 /* periodic route report interval */ +#define ROUTE_SWITCH_TIME 140 /* time to switch to equivalent gw */ +#define ROUTE_EXPIRE_TIME 200 /* time to mark route invalid */ +#define ROUTE_DISCARD_TIME 340 /* time to garbage collect route */ + +#define LEAF_CONFIRMATION_TIME 200 /* time to consider subnet a leaf */ + +#define NEIGHBOR_PROBE_INTERVAL 190 /* periodic neighbor probe interval */ +#define NEIGHBOR_EXPIRE_TIME 140 /* time to consider neighbor gone */ + +#define GROUP_QUERY_INTERVAL 125 /* periodic group query interval */ +#define GROUP_EXPIRE_TIME 270 /* time to consider group gone */ + +#define UNREACHABLE 32 /* "infinity" metric, must be <= 64 */ +#define DEFAULT_METRIC 1 /* default subnet/tunnel metric */ +#define DEFAULT_THRESHOLD 1 /* default subnet/tunnel threshold */ |