usr.sbin/rpc.statd/statd.h

   1 /*
   2  * Copyright (c) 1995
   3  *      A.R. Gordon (andrew.gordon@net-tel.co.uk).  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed for the FreeBSD project
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/usr.sbin/rpc.statd/statd.h,v 1.2.8.1 2002/04/11 17:08:36 alfred Exp $
  33  * $DragonFly: src/usr.sbin/rpc.statd/statd.h,v 1.2 2003/06/17 04:30:02 dillon Exp $
  34  */
  35
  36
  37
  38 #include "sm_inter.h"
  39
  40 /* ------------------------------------------------------------------------- */
  41 /*
  42   Data structures for recording monitored hosts
  43
  44   The information held by the status monitor comprises a list of hosts
  45   that we have been asked to monitor, and, associated with each monitored
  46   host, one or more clients to be called back if the monitored host crashes.
  47
  48   The list of monitored hosts must be retained over a crash, so that upon
  49   re-boot we can call the SM_NOTIFY procedure in all those hosts so as to
  50   cause them to start recovery processing.  On the other hand, the client
  51   call-backs are not required to be preserved: they are assumed (in the
  52   protocol design) to be local processes which will have crashed when
  53   we did, and so are discarded on restart.
  54
  55   We handle this by keeping the list of monitored hosts in a file
  56   (/var/statd.state) which is mmap()ed and whose format is described
  57   by the typedef FileLayout.  The lists of client callbacks are chained
  58   off this structure, but are held in normal memory and so will be
  59   lost after a re-boot.  Hence the actual values of MonList * pointers
  60   in the copy on disc have no significance, but their NULL/non-NULL
  61   status indicates whether this host is actually being monitored or if it
  62   is an empty slot in the file.
  63 */
  64
  65 typedef struct MonList_s
  66 {
  67   struct MonList_s *next;       /* Next in list or NULL                 */
  68   char notifyHost[SM_MAXSTRLEN + 1];    /* Host to notify               */
  69   int notifyProg;               /* RPC program number to call           */
  70   int notifyVers;               /* version number                       */
  71   int notifyProc;               /* procedure number                     */
  72   unsigned char notifyData[16]; /* Opaque data from caller              */
  73 } MonList;
  74
  75 typedef struct
  76 {
  77   char hostname[SM_MAXSTRLEN + 1];      /* Name of monitored host       */
  78   int notifyReqd;               /* TRUE if we've crashed and not yet    */
  79                                 /* informed the monitored host          */
  80   MonList *monList;             /* List of clients to inform if we      */
  81                                 /* hear that the monitored host has     */
  82                                 /* crashed, NULL if no longer monitored */
  83 } HostInfo;
  84
  85
  86 /* Overall file layout.                                                 */
  87
  88 typedef struct
  89 {
  90   int ourState;         /* State number as defined in statd protocol    */
  91   int noOfHosts;        /* Number of elements in hosts[]                */
  92   char reserved[248];   /* Reserved for future use                      */
  93   HostInfo hosts[1];    /* vector of monitored hosts                    */
  94 } FileLayout;
  95
  96 #define HEADER_LEN (sizeof(FileLayout) - sizeof(HostInfo))
  97
  98 /* ------------------------------------------------------------------------- */
  99
 100 /* Global variables             */
 101
 102 extern FileLayout *status_info; /* The mmap()ed status file             */
 103
 104 extern int debug;               /* =1 to enable diagnostics to syslog   */
 105
 106 /* Function prototypes          */
 107
 108 extern HostInfo *find_host(char * /*hostname*/, int /*create*/);
 109 extern void init_file(char * /*filename*/);
 110 extern void notify_hosts(void);
 111 extern void sync_file(void);