NetBSD/usr.sbin/rpc.statd/statd.h

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/* $NetBSD: statd.h,v 1.1 1997/03/10 06:28:32 scottr Exp $ */
/*
* Copyright (c) 1995
* A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the FreeBSD project
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include "sm_inter.h"
/* ------------------------------------------------------------------------- */
/*
* Data structures for recording monitored hosts
*
* The information held by the status monitor comprises a list of hosts
* that we have been asked to monitor, and, associated with each monitored
* host, one or more clients to be called back if the monitored host crashes.
*
* The list of monitored hosts must be retained over a crash, so that upon
* re-boot we can call the SM_NOTIFY procedure in all those hosts so as to
* cause them to start recovery processing. On the other hand, the client
* call-backs are not required to be preserved: they are assumed (in the
* protocol design) to be local processes which will have crashed when
* we did, and so are discarded on restart.
*
* We handle this by keeping the list of monitored hosts in a file
* (/var/statd.state) which is mmap()ed and whose format is described
* by the typedef FileLayout. The lists of client callbacks are chained
* off this structure, but are held in normal memory and so will be
* lost after a re-boot. Hence the actual values of MonList * pointers
* in the copy on disc have no significance, but their NULL/non-NULL
* status indicates whether this host is actually being monitored or if it
* is an empty slot in the file.
*/
typedef struct MonList_s {
struct MonList_s *next; /* Next in list or NULL */
char notifyHost[SM_MAXSTRLEN + 1]; /* Host to notify */
int notifyProg; /* RPC program number to call */
int notifyVers; /* version number */
int notifyProc; /* procedure number */
u_char notifyData[16]; /* Opaque data from caller */
} MonList;
typedef struct {
char hostname[SM_MAXSTRLEN + 1]; /* Name of monitored host */
int notifyReqd; /* TRUE if we've crashed and not yet
informed the monitored host */
MonList *monList; /* List of clients to inform if we
hear that the monitored host has
crashed, NULL if no longer monitored */
} HostInfo;
/* Overall file layout. */
typedef struct {
int ourState; /* State number as defined in statd protocol */
int noOfHosts; /* Number of elements in hosts[] */
char reserved[248]; /* Reserved for future use */
HostInfo hosts[1]; /* vector of monitored hosts */
} FileLayout;
#define HEADER_LEN (sizeof(FileLayout) - sizeof(HostInfo))
/* ------------------------------------------------------------------------- */
/* Global variables */
extern FileLayout *status_info; /* The mmap()ed status file */
extern int debug; /* = 1 to enable diagnostics to syslog */
/* Function prototypes */
extern HostInfo *find_host __P((char *hostname, int create));
extern void init_file __P((char *filename));
extern void notify_hosts __P((void));
extern void sync_file __P((void));