usr.sbin/mrouted/dvmrp.h

   1 /*
   2  * The mrouted program is covered by the license in the accompanying file
   3  * named "LICENSE".  Use of the mrouted program represents acceptance of
   4  * the terms and conditions listed in that file.
   5  *
   6  * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
   7  * Leland Stanford Junior University.
   8  *
   9  *
  10  * $FreeBSD: src/usr.sbin/mrouted/dvmrp.h,v 1.9 1999/08/28 01:17:03 peter Exp $
  11  * $DragonFly: src/usr.sbin/mrouted/dvmrp.h,v 1.2 2003/06/17 04:29:57 dillon Exp $
  12  * dvmrp.h,v 3.8.4.5 1997/11/18 23:25:57 fenner Exp
  13  */
  14
  15 /*
  16  * A DVMRP message consists of an IP header + an IGMP header + (for some types)
  17  * zero or more bytes of data.
  18  *
  19  * For REPORT messages, the data is route information; the route information
  20  * consists of one or more lists of the following form:
  21  *
  22  *              (mask, (origin, metric), (origin, metric), ...)
  23  *
  24  * where:
  25  *
  26  *      "mask" is the subnet mask for all the origins in the list.
  27  *              It is always THREE bytes long, containing the low-order
  28  *              three bytes of the mask (the high-order byte is always
  29  *              0xff and therefore need not be transmitted).
  30  *
  31  *      "origin" is the number of a subnet from which multicast datagrams
  32  *              may originate.  It is from one to four bytes long,
  33  *              depending on the value of "mask":
  34  *                      if all bytes of the mask are zero
  35  *                          the subnet number is one byte long
  36  *                      else if the low-order two bytes of the mask are zero
  37  *                          the subnet number is two bytes long
  38  *                      else if the lowest-order byte of the mask is zero
  39  *                          the subnet number is three bytes long,
  40  *                      else
  41  *                          the subnet number is four bytes long.
  42  *
  43  *      "metric" is a one-byte value consisting of two subfields:
  44  *              - the high-order bit is a flag which, when set, indicates
  45  *                the last (origin, metric) pair of a list.
  46  *              - the low-order seven bits contain the routing metric for
  47  *                the corresponding origin, relative to the sender of the
  48  *                DVMRP report.  The metric may have the value of UNREACHABLE
  49  *                added to it as a "split horizon" indication (so called
  50  *                "poisoned reverse").
  51  *
  52  * Within a list, the origin subnet numbers must be in ascending order, and
  53  * the lists themselves are in order of increasing mask value.  A message may
  54  * not exceed 576 bytes, the default maximum IP reassembly size, including
  55  * the IP and IGMP headers; the route information may be split across more
  56  * than one message if necessary, by terminating a list in one message and
  57  * starting a new list in the next message (repeating the same mask value,
  58  * if necessary).
  59  *
  60  * For NEIGHBORS messages, the data is neighboring-router information
  61  * consisting of one or more lists of the following form:
  62  *
  63  *      (local-addr, metric, threshold, ncount, neighbor, neighbor, ...)
  64  *
  65  * where:
  66  *
  67  *      "local-addr" is the sending router's address as seen by the neighbors
  68  *                   in this list; it is always four bytes long.
  69  *      "metric" is a one-byte unsigned value, the TTL `cost' of forwarding
  70  *               packets to any of the neighbors on this list.
  71  *      "threshold" is a one-byte unsigned value, a lower bound on the TTL a
  72  *                  packet must have to be forwarded to any of the neighbors on
  73  *                  this list.
  74  *      "ncount" is the number of neighbors in this list.
  75  *      "neighbor" is the address of a neighboring router, four bytes long.
  76  *
  77  * As with REPORT messages, NEIGHBORS messages should not exceed 576 bytes,
  78  * including the IP and IGMP headers; split longer messages by terminating the
  79  * list in one and continuing in another, repeating the local-addr, etc., if
  80  * necessary.
  81  *
  82  * For NEIGHBORS2 messages, the data is identical to NEIGHBORS except
  83  * there is a flags byte before the neighbor count:
  84  *
  85  *      (local-addr, metric, threshold, flags, ncount, neighbor, neighbor, ...)
  86  */
  87
  88 /*
  89  * DVMRP message types (carried in the "code" field of an IGMP header)
  90  */
  91 #define DVMRP_PROBE             1       /* for finding neighbors             */
  92 #define DVMRP_REPORT            2       /* for reporting some or all routes  */
  93 #define DVMRP_ASK_NEIGHBORS     3       /* sent by mapper, asking for a list */
  94                                         /* of this router's neighbors. */
  95 #define DVMRP_NEIGHBORS         4       /* response to such a request */
  96 #define DVMRP_ASK_NEIGHBORS2    5       /* as above, want new format reply */
  97 #define DVMRP_NEIGHBORS2        6
  98 #define DVMRP_PRUNE             7       /* prune message */
  99 #define DVMRP_GRAFT             8       /* graft message */
 100 #define DVMRP_GRAFT_ACK         9       /* graft acknowledgement */
 101 #define DVMRP_INFO_REQUEST      10      /* information request */
 102 #define DVMRP_INFO_REPLY        11      /* information reply */
 103
 104 /*
 105  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
 106  */
 107 #define DVMRP_NF_TUNNEL         0x01    /* neighbors reached via tunnel */
 108 #define DVMRP_NF_SRCRT          0x02    /* tunnel uses IP source routing */
 109 #define DVMRP_NF_PIM            0x04    /* neighbor is a PIM neighbor */
 110 #define DVMRP_NF_DOWN           0x10    /* kernel state of interface */
 111 #define DVMRP_NF_DISABLED       0x20    /* administratively disabled */
 112 #define DVMRP_NF_QUERIER        0x40    /* I am the subnet's querier */
 113 #define DVMRP_NF_LEAF           0x80    /* Neighbor reports that it is a leaf */
 114
 115 /*
 116  * Request/reply types for info queries/replies
 117  */
 118 #define DVMRP_INFO_VERSION      1       /* version string */
 119 #define DVMRP_INFO_NEIGHBORS    2       /* neighbors2 data */
 120
 121 /*
 122  * Limit on length of route data
 123  */
 124 #define MAX_IP_PACKET_LEN       576
 125 #define MIN_IP_HEADER_LEN       20
 126 #define MAX_IP_HEADER_LEN       60
 127 #define MAX_DVMRP_DATA_LEN \
 128                 ( MAX_IP_PACKET_LEN - MAX_IP_HEADER_LEN - IGMP_MINLEN )
 129
 130 /*
 131  * Various protocol constants (all times in seconds)
 132  */
 133                                         /* address for multicast DVMRP msgs */
 134 #define INADDR_DVMRP_GROUP      (u_int32)0xe0000004     /* 224.0.0.4 */
 135 /*
 136  * The IGMPv2 <netinet/in.h> defines INADDR_ALLRTRS_GROUP, but earlier
 137  * ones don't, so we define it conditionally here.
 138  */
 139 #ifndef INADDR_ALLRTRS_GROUP
 140                                         /* address for multicast mtrace msg */
 141 #define INADDR_ALLRTRS_GROUP    (u_int32)0xe0000002     /* 224.0.0.2 */
 142 #endif
 143
 144 #define ROUTE_MAX_REPORT_DELAY  5       /* max delay for reporting changes  */
 145                                         /*  (This is the timer interrupt    */
 146                                         /*  interval; all times must be     */
 147                                         /*  multiples of this value.)       */
 148
 149 #define ROUTE_REPORT_INTERVAL   60      /* periodic route report interval   */
 150 #define ROUTE_SWITCH_TIME       140     /* time to switch to equivalent gw  */
 151 #define ROUTE_EXPIRE_TIME       200     /* time to mark route invalid       */
 152 #define ROUTE_DISCARD_TIME      340     /* time to garbage collect route    */
 153
 154 #define LEAF_CONFIRMATION_TIME  200     /* time to consider subnet a leaf   */
 155
 156 #define NEIGHBOR_PROBE_INTERVAL 10      /* periodic neighbor probe interval */
 157 #define NEIGHBOR_EXPIRE_TIME    30      /* time to consider neighbor gone   */
 158 #define OLD_NEIGHBOR_EXPIRE_TIME 140    /* time to consider neighbor gone   */
 159
 160 #define UNREACHABLE             32      /* "infinity" metric, must be <= 64 */
 161 #define DEFAULT_METRIC          1       /* default subnet/tunnel metric     */
 162 #define DEFAULT_THRESHOLD       1       /* default subnet/tunnel threshold  */
 163
 164 #define MAX_RATE_LIMIT          100000  /* max rate limit                   */
 165 #define DEFAULT_PHY_RATE_LIMIT  0       /* default phyint rate limit        */
 166 #define DEFAULT_TUN_RATE_LIMIT  0       /* default tunnel rate limit        */
 167
 168 #define DEFAULT_CACHE_LIFETIME  300     /* kernel route entry discard time  */
 169 #define MIN_CACHE_LIFETIME      60      /* minimum allowed cache lifetime   */
 170 #define AVERAGE_PRUNE_LIFETIME  7200    /* average lifetime of prunes sent  */
 171 #define MIN_PRUNE_LIFETIME      120     /* minimum allowed prune lifetime   */
 172 #define GRAFT_TIMEOUT_VAL       5       /* retransmission time for grafts   */
 173 #define PRUNE_REXMIT_VAL        3       /* initial time for prune rexmission*/