/* $NetBSD: dvmrp.h,v 1.5 1995/12/10 10:07:00 mycroft Exp $ */ /* * 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. */ /* * 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 #define DVMRP_PRUNE 7 /* prune message */ #define DVMRP_GRAFT 8 /* graft message */ #define DVMRP_GRAFT_ACK 9 /* graft acknowledgement */ #define DVMRP_INFO_REQUEST 10 /* information request */ #define DVMRP_INFO_REPLY 11 /* information reply */ /* * '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_PIM 0x04 /* neighbor is a PIM neighbor */ #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 */ #define DVMRP_NF_LEAF 0x80 /* Neighbor reports that it is a leaf */ /* * Request/reply types for info queries/replies */ #define DVMRP_INFO_VERSION 1 /* version string */ #define DVMRP_INFO_NEIGHBORS 2 /* neighbors2 data */ /* * 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_int32_t)0xe0000004 /* 224.0.0.4 */ /* * The IGMPv2 <netinet/in.h> defines INADDR_ALLRTRS_GROUP, but earlier * ones don't, so we define it conditionally here. */ #ifndef INADDR_ALLRTRS_GROUP /* address for multicast mtrace msg */ #define INADDR_ALLRTRS_GROUP (u_int32_t)0xe0000002 /* 224.0.0.2 */ #endif #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 10 /* 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 LEAVE_EXPIRE_TIME 3 /* " " after receiving a leave */ /* Note: LEAVE_EXPIRE_TIME should ideally be shorter, but the resolution of * the timer in mrouted doesn't allow us to make it any shorter. */ #define UNREACHABLE 32 /* "infinity" metric, must be <= 64 */ #define DEFAULT_METRIC 1 /* default subnet/tunnel metric */ #define DEFAULT_THRESHOLD 1 /* default subnet/tunnel threshold */ #define MAX_RATE_LIMIT 100000 /* max rate limit */ #define DEFAULT_PHY_RATE_LIMIT 0 /* default phyint rate limit */ #define DEFAULT_TUN_RATE_LIMIT 500 /* default tunnel rate limit */ #define DEFAULT_CACHE_LIFETIME 300 /* kernel route entry discard time */ #define GRAFT_TIMEOUT_VAL 5 /* retransmission time for grafts */ #define OLD_AGE_THRESHOLD 2
