usr.sbin/mrouted/dvmrp.h

   1 /*      $NetBSD: dvmrp.h,v 1.1 2002/10/01 03:31:07 itojun Exp $ */
   2
   3 /*
   4  * The mrouted program is covered by the license in the accompanying file
   5  * named "LICENSE".  Use of the mrouted program represents acceptance of
   6  * the terms and conditions listed in that file.
   7  *
   8  * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
   9  * Leland Stanford Junior University.
  10  */
  11
  12 /*
  13  * A DVMRP message consists of an IP header + an IGMP header + (for some types)
  14  * zero or more bytes of data.
  15  *
  16  * For REPORT messages, the data is route information; the route information
  17  * consists of one or more lists of the following form:
  18  *
  19  *              (mask, (origin, metric), (origin, metric), ...)
  20  *
  21  * where:
  22  *
  23  *      "mask" is the subnet mask for all the origins in the list.
  24  *              It is always THREE bytes long, containing the low-order
  25  *              three bytes of the mask (the high-order byte is always
  26  *              0xff and therefore need not be transmitted).
  27  *
  28  *      "origin" is the number of a subnet from which multicast datagrams
  29  *              may originate.  It is from one to four bytes long,
  30  *              depending on the value of "mask":
  31  *                      if all bytes of the mask are zero
  32  *                          the subnet number is one byte long
  33  *                      else if the low-order two bytes of the mask are zero
  34  *                          the subnet number is two bytes long
  35  *                      else if the lowest-order byte of the mask is zero
  36  *                          the subnet number is three bytes long,
  37  *                      else
  38  *                          the subnet number is four bytes long.
  39  *
  40  *      "metric" is a one-byte value consisting of two subfields:
  41  *              - the high-order bit is a flag which, when set, indicates
  42  *                the last (origin, metric) pair of a list.
  43  *              - the low-order seven bits contain the routing metric for
  44  *                the corresponding origin, relative to the sender of the
  45  *                DVMRP report.  The metric may have the value of UNREACHABLE
  46  *                added to it as a "split horizon" indication (so called
  47  *                "poisoned reverse").
  48  *
  49  * Within a list, the origin subnet numbers must be in ascending order, and
  50  * the lists themselves are in order of increasing mask value.  A message may
  51  * not exceed 576 bytes, the default maximum IP reassembly size, including
  52  * the IP and IGMP headers; the route information may be split across more
  53  * than one message if necessary, by terminating a list in one message and
  54  * starting a new list in the next message (repeating the same mask value,
  55  * if necessary).
  56  *
  57  * For NEIGHBORS messages, the data is neighboring-router information
  58  * consisting of one or more lists of the following form:
  59  *
  60  *      (local-addr, metric, threshold, ncount, neighbor, neighbor, ...)
  61  *
  62  * where:
  63  *
  64  *      "local-addr" is the sending router's address as seen by the neighbors
  65  *                   in this list; it is always four bytes long.
  66  *      "metric" is a one-byte unsigned value, the TTL `cost' of forwarding
  67  *               packets to any of the neighbors on this list.
  68  *      "threshold" is a one-byte unsigned value, a lower bound on the TTL a
  69  *                  packet must have to be forwarded to any of the neighbors on
  70  *                  this list.
  71  *      "ncount" is the number of neighbors in this list.
  72  *      "neighbor" is the address of a neighboring router, four bytes long.
  73  *
  74  * As with REPORT messages, NEIGHBORS messages should not exceed 576 bytes,
  75  * including the IP and IGMP headers; split longer messages by terminating the
  76  * list in one and continuing in another, repeating the local-addr, etc., if
  77  * necessary.
  78  *
  79  * For NEIGHBORS2 messages, the data is identical to NEIGHBORS except
  80  * there is a flags byte before the neighbor count:
  81  *
  82  *      (local-addr, metric, threshold, flags, ncount, neighbor, neighbor, ...)
  83  */
  84
  85 /*
  86  * DVMRP message types (carried in the "code" field of an IGMP header)
  87  */
  88 #define DVMRP_PROBE             1       /* for finding neighbors             */
  89 #define DVMRP_REPORT            2       /* for reporting some or all routes  */
  90 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  91                                         /* of this router's neighbors. */
  92 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  93 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  94 #define DVMRP_NEIGHBORS2        6
  95 #define DVMRP_PRUNE             7       /* prune message */
  96 #define DVMRP_GRAFT             8       /* graft message */
  97 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
  98 #define DVMRP_INFO_REQUEST      10      /* information request */
  99 #define DVMRP_INFO_REPLY        11      /* information reply */
 100
 101 /*
 102  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
 103  */
 104 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
 105 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
 106 #define DVMRP_NF_PIM            0x04    /* neighbor is a PIM neighbor */
 107 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
 108 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
 109 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
 110 #define DVMRP_NF_LEAF           0x80    /* Neighbor reports that it is a leaf */
 111
 112 /*
 113  * Request/reply types for info queries/replies
 114  */
 115 #define DVMRP_INFO_VERSION      1       /* version string */
 116 #define DVMRP_INFO_NEIGHBORS    2       /* neighbors2 data */
 117
 118 /*
 119  * Limit on length of route data
 120  */
 121 #define MAX_IP_PACKET_LEN       576
 122 #define MIN_IP_HEADER_LEN       20
 123 #define MAX_IP_HEADER_LEN       60
 124 #define MAX_DVMRP_DATA_LEN \
 125                 ( MAX_IP_PACKET_LEN - MAX_IP_HEADER_LEN - IGMP_MINLEN )
 126
 127 /*
 128  * Various protocol constants (all times in seconds)
 129  */
 130                                         /* address for multicast DVMRP msgs */
 131 #define INADDR_DVMRP_GROUP      (u_int32_t)0xe0000004     /* 224.0.0.4 */
 132 /*
 133  * The IGMPv2 <netinet/in.h> defines INADDR_ALLRTRS_GROUP, but earlier
 134  * ones don't, so we define it conditionally here.
 135  */
 136 #ifndef INADDR_ALLRTRS_GROUP
 137                                         /* address for multicast mtrace msg */
 138 #define INADDR_ALLRTRS_GROUP    (u_int32_t)0xe0000002   /* 224.0.0.2 */
 139 #endif
 140
 141 #define ROUTE_MAX_REPORT_DELAY  5       /* max delay for reporting changes  */
 142                                         /*  (This is the timer interrupt    */
 143                                         /*  interval; all times must be     */
 144                                         /*  multiples of this value.)       */
 145
 146 #define ROUTE_REPORT_INTERVAL   60      /* periodic route report interval   */
 147 #define ROUTE_SWITCH_TIME       140     /* time to switch to equivalent gw  */
 148 #define ROUTE_EXPIRE_TIME       200     /* time to mark route invalid       */
 149 #define ROUTE_DISCARD_TIME      340     /* time to garbage collect route    */
 150
 151 #define LEAF_CONFIRMATION_TIME  200     /* time to consider subnet a leaf   */
 152
 153 #define NEIGHBOR_PROBE_INTERVAL 10      /* periodic neighbor probe interval */
 154 #define NEIGHBOR_EXPIRE_TIME    140     /* time to consider neighbor gone   */
 155
 156 #define GROUP_QUERY_INTERVAL    125     /* periodic group query interval    */
 157 #define GROUP_EXPIRE_TIME       270     /* time to consider group gone      */
 158 #define LEAVE_EXPIRE_TIME       3       /* " " after receiving a leave      */
 159 /* Note: LEAVE_EXPIRE_TIME should ideally be shorter, but the resolution of
 160  * the timer in mrouted doesn't allow us to make it any shorter. */
 161
 162 #define UNREACHABLE             32      /* "infinity" metric, must be <= 64 */
 163 #define DEFAULT_METRIC          1       /* default subnet/tunnel metric     */
 164 #define DEFAULT_THRESHOLD       1       /* default subnet/tunnel threshold  */
 165
 166 #define MAX_RATE_LIMIT          100000  /* max rate limit                   */
 167 #define DEFAULT_PHY_RATE_LIMIT  0       /* default phyint rate limit        */
 168 #define DEFAULT_TUN_RATE_LIMIT  500     /* default tunnel rate limit        */
 169
 170 #define DEFAULT_CACHE_LIFETIME  300     /* kernel route entry discard time  */
 171 #define GRAFT_TIMEOUT_VAL       5       /* retransmission time for grafts   */
 172
 173 #define OLD_AGE_THRESHOLD       2