freebsd-skq/usr.sbin/rpc.statd/procs.c
Alfred Perlstein a2015ce534 Fix return values in the sm_notify_1 service routine to return an answer
most of the time (unless fork fails).  This should fix the problem where
FreeBSD won't respond to a remote host and therefor the remote hosts
tries indefinitely to contact the FreeBSD hosts thereby irritating the
system administrator.

PR: misc/27810
2002-07-11 17:39:50 +00:00

416 lines
12 KiB
C

/*
* 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.
*
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <syslog.h>
#include <vis.h>
#include <netdb.h> /* for gethostbyname() */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "statd.h"
/* sm_check_hostname -------------------------------------------------------- */
/*
* Purpose: Check `mon_name' member of sm_name struct to ensure that the array
* consists only of printable characters.
*
* Returns: TRUE if hostname is good. FALSE if hostname contains binary or
* otherwise non-printable characters.
*
* Notes: Will syslog(3) to warn of corrupt hostname.
*/
int sm_check_hostname(struct svc_req *req, char *arg)
{
int len, dstlen, ret;
struct sockaddr_in *claddr;
char *dst;
len = strlen(arg);
dstlen = (4 * len) + 1;
dst = malloc(dstlen);
claddr = svc_getcaller(req->rq_xprt);
ret = 1;
if (claddr == NULL || dst == NULL)
{
ret = 0;
}
else if (strvis(dst, arg, VIS_WHITE) != len)
{
syslog(LOG_ERR,
"sm_stat: client %s hostname %s contained invalid characters.",
inet_ntoa(claddr->sin_addr),
dst);
ret = 0;
}
free(dst);
return (ret);
}
/* sm_stat_1 --------------------------------------------------------------- */
/*
Purpose: RPC call to enquire if a host can be monitored
Returns: TRUE for any hostname that can be looked up to give
an address.
*/
struct sm_stat_res *sm_stat_1_svc(sm_name *arg, struct svc_req *req)
{
static sm_stat_res res;
static int err;
err = 1;
if ((err = sm_check_hostname(req, arg->mon_name)) == 0)
{
res.res_stat = stat_fail;
}
if (err != 0)
{
if (debug)
syslog(LOG_DEBUG, "stat called for host %s", arg->mon_name);
if (gethostbyname(arg->mon_name))
res.res_stat = stat_succ;
else
{
syslog(LOG_ERR, "invalid hostname to sm_stat: %s", arg->mon_name);
res.res_stat = stat_fail;
}
}
res.state = status_info->ourState;
return (&res);
}
/* sm_mon_1 ---------------------------------------------------------------- */
/*
Purpose: RPC procedure to establish a monitor request
Returns: Success, unless lack of resources prevents
the necessary structures from being set up
to record the request, or if the hostname is not
valid (as judged by gethostbyname())
*/
struct sm_stat_res *sm_mon_1_svc(mon *arg, struct svc_req *req)
{
static sm_stat_res res;
HostInfo *hp;
static int err;
MonList *lp;
if ((err = sm_check_hostname(req, arg->mon_id.mon_name)) == 0)
{
res.res_stat = stat_fail;
}
if (err != 0)
{
if (debug)
{
syslog(LOG_DEBUG, "monitor request for host %s", arg->mon_id.mon_name);
syslog(LOG_DEBUG, "recall host: %s prog: %d ver: %d proc: %d",
arg->mon_id.mon_name,
arg->mon_id.my_id.my_prog, arg->mon_id.my_id.my_vers,
arg->mon_id.my_id.my_proc);
}
res.res_stat = stat_fail; /* Assume fail until set otherwise */
res.state = status_info->ourState;
/* Find existing host entry, or create one if not found */
/* If find_host() fails, it will have logged the error already. */
if (!gethostbyname(arg->mon_id.mon_name))
{
syslog(LOG_ERR, "Invalid hostname to sm_mon: %s", arg->mon_id.mon_name);
}
else if ((hp = find_host(arg->mon_id.mon_name, TRUE)))
{
lp = (MonList *)malloc(sizeof(MonList));
if (!lp)
{
syslog(LOG_ERR, "Out of memory");
}
else
{
strncpy(lp->notifyHost, arg->mon_id.my_id.my_name, SM_MAXSTRLEN);
lp->notifyProg = arg->mon_id.my_id.my_prog;
lp->notifyVers = arg->mon_id.my_id.my_vers;
lp->notifyProc = arg->mon_id.my_id.my_proc;
memcpy(lp->notifyData, arg->priv, sizeof(lp->notifyData));
lp->next = hp->monList;
hp->monList = lp;
sync_file();
res.res_stat = stat_succ; /* Report success */
}
}
}
return (&res);
}
/* do_unmon ---------------------------------------------------------------- */
/*
Purpose: Remove a monitor request from a host
Returns: TRUE if found, FALSE if not found.
Notes: Common code from sm_unmon_1_svc and sm_unmon_all_1_svc
In the unlikely event of more than one identical monitor
request, all are removed.
*/
static int do_unmon(HostInfo *hp, my_id *idp)
{
MonList *lp, *next;
MonList *last = NULL;
int result = FALSE;
lp = hp->monList;
while (lp)
{
if (!strncasecmp(idp->my_name, lp->notifyHost, SM_MAXSTRLEN)
&& (idp->my_prog == lp->notifyProg) && (idp->my_proc == lp->notifyProc)
&& (idp->my_vers == lp->notifyVers))
{
/* found one. Unhook from chain and free. */
next = lp->next;
if (last) last->next = next;
else hp->monList = next;
free(lp);
lp = next;
result = TRUE;
}
else
{
last = lp;
lp = lp->next;
}
}
return (result);
}
/* sm_unmon_1 -------------------------------------------------------------- */
/*
Purpose: RPC procedure to release a monitor request.
Returns: Local machine's status number
Notes: The supplied mon_id should match the value passed in an
earlier call to sm_mon_1
*/
struct sm_stat *sm_unmon_1_svc(mon_id *arg, struct svc_req *req)
{
static sm_stat res;
HostInfo *hp;
if (debug)
{
syslog(LOG_DEBUG, "un-monitor request for host %s", arg->mon_name);
syslog(LOG_DEBUG, "recall host: %s prog: %d ver: %d proc: %d",
arg->mon_name,
arg->my_id.my_prog, arg->my_id.my_vers, arg->my_id.my_proc);
}
if ((hp = find_host(arg->mon_name, FALSE)))
{
if (do_unmon(hp, &arg->my_id)) sync_file();
else
{
syslog(LOG_ERR, "unmon request from %s, no matching monitor",
arg->my_id.my_name);
}
}
else syslog(LOG_ERR, "unmon request from %s for unknown host %s",
arg->my_id.my_name, arg->mon_name);
res.state = status_info->ourState;
return (&res);
}
/* sm_unmon_all_1 ---------------------------------------------------------- */
/*
Purpose: RPC procedure to release monitor requests.
Returns: Local machine's status number
Notes: Releases all monitor requests (if any) from the specified
host and program number.
*/
struct sm_stat *sm_unmon_all_1_svc(my_id *arg, struct svc_req *req)
{
static sm_stat res;
HostInfo *hp;
int i;
if (debug)
{
syslog(LOG_DEBUG, "unmon_all for host: %s prog: %d ver: %d proc: %d",
arg->my_name, arg->my_prog, arg->my_vers, arg->my_proc);
}
for (i = status_info->noOfHosts, hp = status_info->hosts; i; i--, hp++)
{
do_unmon(hp, arg);
}
sync_file();
res.state = status_info->ourState;
return (&res);
}
/* sm_simu_crash_1 --------------------------------------------------------- */
/*
Purpose: RPC procedure to simulate a crash
Returns: Nothing
Notes: Standardised mechanism for debug purposes
The specification says that we should drop all of our
status information (apart from the list of monitored hosts
on disc). However, this would confuse the rpc.lockd
which would be unaware that all of its monitor requests
had been silently junked. Hence we in fact retain all
current requests and simply increment the status counter
and inform all hosts on the monitor list.
*/
void *sm_simu_crash_1_svc(void *v, struct svc_req *req)
{
static char dummy;
int work_to_do;
HostInfo *hp;
int i;
if (debug) syslog(LOG_DEBUG, "simu_crash called!!");
/* Simulate crash by setting notify-required flag on all monitored */
/* hosts, and incrementing our status number. notify_hosts() is */
/* then called to fork a process to do the notifications. */
for (i = status_info->noOfHosts, hp = status_info->hosts; i ; i--, hp++)
{
if (hp->monList)
{
work_to_do = TRUE;
hp->notifyReqd = TRUE;
}
}
status_info->ourState += 2; /* always even numbers if not crashed */
if (work_to_do) notify_hosts();
return (&dummy);
}
/* sm_notify_1 ------------------------------------------------------------- */
/*
Purpose: RPC procedure notifying local statd of the crash of another
Returns: Nothing
Notes: There is danger of deadlock, since it is quite likely that
the client procedure that we call will in turn call us
to remove or adjust the monitor request.
We therefore fork() a process to do the notifications.
Note that the main HostInfo structure is in a mmap()
region and so will be shared with the child, but the
monList pointed to by the HostInfo is in normal memory.
Hence if we read the monList before forking, we are
protected from the parent servicing other requests
that modify the list.
*/
void *sm_notify_1_svc(stat_chge *arg, struct svc_req *req)
{
struct timeval timeout = { 20, 0 }; /* 20 secs timeout */
CLIENT *cli;
static char dummy;
sm_status tx_arg; /* arg sent to callback procedure */
MonList *lp;
HostInfo *hp;
pid_t pid;
if (debug) syslog(LOG_DEBUG, "notify from host %s, new state %d",
arg->mon_name, arg->state);
hp = find_host(arg->mon_name, FALSE);
if (!hp)
{
/* Never heard of this host - why is it notifying us? */
syslog(LOG_ERR, "Unsolicited notification from host %s", arg->mon_name);
return (&dummy);
}
lp = hp->monList;
if (!lp) return (&dummy); /* We know this host, but have no */
/* outstanding requests. */
pid = fork();
if (pid == -1)
{
syslog(LOG_ERR, "Unable to fork notify process - %s", strerror(errno));
return (NULL); /* no answer, the client will retry */
}
if (pid) return (&dummy); /* Parent returns */
while (lp)
{
tx_arg.mon_name = arg->mon_name;
tx_arg.state = arg->state;
memcpy(tx_arg.priv, lp->notifyData, sizeof(tx_arg.priv));
cli = clnt_create(lp->notifyHost, lp->notifyProg, lp->notifyVers, "udp");
if (!cli)
{
syslog(LOG_ERR, "Failed to contact host %s%s", lp->notifyHost,
clnt_spcreateerror(""));
}
else
{
if (clnt_call(cli, lp->notifyProc, xdr_sm_status, &tx_arg, xdr_void,
&dummy, timeout) != RPC_SUCCESS)
{
syslog(LOG_ERR, "Failed to call rpc.statd client at host %s",
lp->notifyHost);
}
clnt_destroy(cli);
}
lp = lp->next;
}
exit (0); /* Child quits */
}