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stat_proc.c revision 1.7
      1 /*	$NetBSD: stat_proc.c,v 1.7 2005/11/03 19:36:42 bouyer Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995
      5  *	A.R. Gordon (andrew.gordon (at) net-tel.co.uk).  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed for the FreeBSD project
     18  * 4. Neither the name of the author nor the names of any co-contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  *
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __RCSID("$NetBSD: stat_proc.c,v 1.7 2005/11/03 19:36:42 bouyer Exp $");
     39 #endif
     40 
     41 #include <errno.h>
     42 #include <netdb.h>
     43 #include <stdio.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 #include <syslog.h>
     47 #include <signal.h>
     48 #include <unistd.h>
     49 
     50 #include <rpc/rpc.h>
     51 
     52 #include "statd.h"
     53 
     54 /* sm_stat_1 --------------------------------------------------------------- */
     55 /*
     56  * Purpose:	RPC call to enquire if a host can be monitored
     57  * Returns:	TRUE for any hostname that can be looked up to give
     58  *		an address.
     59  */
     60 struct sm_stat_res *
     61 sm_stat_1_svc(arg, req)
     62 	sm_name *arg;
     63 	struct svc_req *req;
     64 {
     65 	static sm_stat_res res;
     66 	struct addrinfo *ai;
     67 
     68 	NO_ALARM;
     69 	if (debug)
     70 		syslog(LOG_DEBUG, "stat called for host %s", arg->mon_name);
     71 
     72 	if (getaddrinfo(arg->mon_name, NULL, NULL, &ai) == 0) {
     73 		res.res_stat = stat_succ;
     74 		freeaddrinfo(ai);
     75 	} else {
     76 		syslog(LOG_ERR, "invalid hostname to sm_stat: %s",
     77 		    arg->mon_name);
     78 		res.res_stat = stat_fail;
     79 	}
     80 
     81 	res.state = status_info.ourState;
     82 	ALARM;
     83 	return (&res);
     84 }
     85 
     86 /* sm_mon_1 ---------------------------------------------------------------- */
     87 /*
     88  * Purpose:	RPC procedure to establish a monitor request
     89  * Returns:	Success, unless lack of resources prevents
     90  *		the necessary structures from being set up
     91  *		to record the request, or if the hostname is not
     92  *		valid (as judged by gethostbyname())
     93  */
     94 struct sm_stat_res *
     95 sm_mon_1_svc(arg, req)
     96 	mon *arg;
     97 	struct svc_req *req;
     98 {
     99 	static sm_stat_res res;
    100 	struct addrinfo *ai;
    101 	HostInfo *hp, h;
    102 	MonList *lp;
    103 
    104 	NO_ALARM;
    105 	if (debug) {
    106 		syslog(LOG_DEBUG, "monitor request for host %s",
    107 		    arg->mon_id.mon_name);
    108 		syslog(LOG_DEBUG, "recall host: %s prog: %d ver: %d proc: %d",
    109 		    arg->mon_id.my_id.my_name, arg->mon_id.my_id.my_prog,
    110 		    arg->mon_id.my_id.my_vers, arg->mon_id.my_id.my_proc);
    111 	}
    112 	res.res_stat = stat_fail;	/* Assume fail until set otherwise */
    113 	res.state = status_info.ourState;
    114 
    115 	/*
    116 	 * Find existing host entry, or create one if not found.  If
    117 	 * find_host() fails, it will have logged the error already.
    118 	 */
    119 	if (getaddrinfo(arg->mon_id.mon_name, NULL, NULL, &ai) != 0) {
    120 		syslog(LOG_ERR, "Invalid hostname to sm_mon: %s",
    121 		    arg->mon_id.mon_name);
    122 		return &res;
    123 	}
    124 
    125 	freeaddrinfo(ai);
    126 
    127 	if ((hp = find_host(arg->mon_id.mon_name, &h)) == NULL)
    128 		memset(hp = &h, 0, sizeof(h));
    129 
    130 	lp = (MonList *)malloc(sizeof(MonList));
    131 	if (!lp)
    132 		syslog(LOG_ERR, "Out of memory");
    133 	else {
    134 		strncpy(lp->notifyHost, arg->mon_id.my_id.my_name,
    135 		    SM_MAXSTRLEN);
    136 		lp->notifyProg = arg->mon_id.my_id.my_prog;
    137 		lp->notifyVers = arg->mon_id.my_id.my_vers;
    138 		lp->notifyProc = arg->mon_id.my_id.my_proc;
    139 		memcpy(lp->notifyData, arg->priv,
    140 		    sizeof(lp->notifyData));
    141 
    142 		lp->next = hp->monList;
    143 		hp->monList = lp;
    144 		change_host(arg->mon_id.mon_name, hp);
    145 		sync_file();
    146 		res.res_stat = stat_succ;	/* Report success */
    147 	}
    148 	ALARM;
    149 	return (&res);
    150 }
    151 
    152 /* do_unmon ---------------------------------------------------------------- */
    153 /*
    154  * Purpose:	Remove a monitor request from a host
    155  * Returns:	TRUE if found, FALSE if not found.
    156  * Notes:	Common code from sm_unmon_1_svc and sm_unmon_all_1_svc
    157  *		In the unlikely event of more than one identical monitor
    158  *		request, all are removed.
    159  */
    160 int
    161 do_unmon(name, hp, ptr)
    162 	char *name;
    163 	HostInfo *hp;
    164 	void *ptr;
    165 {
    166 	my_id *idp = ptr;
    167 	MonList *lp, *next;
    168 	MonList *last = NULL;
    169 	int result = FALSE;
    170 
    171 	lp = hp->monList;
    172 	while (lp) {
    173 		if (!strncasecmp(idp->my_name, lp->notifyHost, SM_MAXSTRLEN)
    174 		    && (idp->my_prog == lp->notifyProg)
    175 		    && (idp->my_proc == lp->notifyProc)
    176 		    && (idp->my_vers == lp->notifyVers)) {
    177 			/* found one.  Unhook from chain and free. */
    178 			next = lp->next;
    179 			if (last)
    180 				last->next = next;
    181 			else
    182 				hp->monList = next;
    183 			free(lp);
    184 			lp = next;
    185 			result = TRUE;
    186 		} else {
    187 			last = lp;
    188 			lp = lp->next;
    189 		}
    190 	}
    191 	return (result);
    192 }
    193 
    194 /* sm_unmon_1 -------------------------------------------------------------- */
    195 /*
    196  * Purpose:	RPC procedure to release a monitor request.
    197  * Returns:	Local machine's status number
    198  * Notes:	The supplied mon_id should match the value passed in an
    199  *		earlier call to sm_mon_1
    200  */
    201 struct sm_stat *
    202 sm_unmon_1_svc(arg, req)
    203 	mon_id *arg;
    204 	struct svc_req *req;
    205 {
    206 	static sm_stat res;
    207 	HostInfo *hp, h;
    208 
    209 	NO_ALARM;
    210 	if (debug) {
    211 		syslog(LOG_DEBUG, "un-monitor request for host %s",
    212 		    arg->mon_name);
    213 		syslog(LOG_DEBUG, "recall host: %s prog: %d ver: %d proc: %d",
    214 		    arg->my_id.my_name, arg->my_id.my_prog,
    215 		    arg->my_id.my_vers, arg->my_id.my_proc);
    216 	}
    217 	if ((hp = find_host(arg->mon_name, &h)) != NULL) {
    218 		if (do_unmon(arg->mon_name, hp, &arg->my_id)) {
    219 			change_host(arg->mon_name, hp);
    220 			sync_file();
    221 		}
    222 		else
    223 			syslog(LOG_ERR,
    224 			    "unmon request from %s, no matching monitor",
    225 			    arg->my_id.my_name);
    226 	} else
    227 		syslog(LOG_ERR, "unmon request from %s for unknown host %s",
    228 		    arg->my_id.my_name, arg->mon_name);
    229 
    230 	res.state = status_info.ourState;
    231 	ALARM;
    232 
    233 	return (&res);
    234 }
    235 
    236 /* sm_unmon_all_1 ---------------------------------------------------------- */
    237 /*
    238  * Purpose:	RPC procedure to release monitor requests.
    239  * Returns:	Local machine's status number
    240  * Notes:	Releases all monitor requests (if any) from the specified
    241  *		host and program number.
    242  */
    243 struct sm_stat *
    244 sm_unmon_all_1_svc(arg, req)
    245 	my_id *arg;
    246 	struct svc_req *req;
    247 {
    248 	static sm_stat res;
    249 
    250 	NO_ALARM;
    251 	if (debug) {
    252 		syslog(LOG_DEBUG,
    253 		    "unmon_all for host: %s prog: %d ver: %d proc: %d",
    254 		    arg->my_name, arg->my_prog, arg->my_vers, arg->my_proc);
    255 	}
    256 
    257 	unmon_hosts();
    258 	sync_file();
    259 
    260 	res.state = status_info.ourState;
    261 	ALARM;
    262 
    263 	return (&res);
    264 }
    265 
    266 /* sm_simu_crash_1 --------------------------------------------------------- */
    267 /*
    268  * Purpose:	RPC procedure to simulate a crash
    269  * Returns:	Nothing
    270  * Notes:	Standardised mechanism for debug purposes
    271  *		The specification says that we should drop all of our
    272  *		status information (apart from the list of monitored hosts
    273  *		on disc).  However, this would confuse the rpc.lockd
    274  *		which would be unaware that all of its monitor requests
    275  *		had been silently junked.  Hence we in fact retain all
    276  *		current requests and simply increment the status counter
    277  *		and inform all hosts on the monitor list.
    278  */
    279 void *
    280 sm_simu_crash_1_svc(v, req)
    281 	void *v;
    282 	struct svc_req *req;
    283 {
    284 	static char dummy;
    285 
    286 	NO_ALARM;
    287 	if (debug)
    288 		syslog(LOG_DEBUG, "simu_crash called!!");
    289 
    290 	reset_database();
    291 	ALARM;
    292 	notify_handler(0);
    293 
    294 	return (&dummy);
    295 }
    296 
    297 /* sm_notify_1 ------------------------------------------------------------- */
    298 /*
    299  * Purpose:	RPC procedure notifying local statd of the crash of another
    300  * Returns:	Nothing
    301  * Notes:	There is danger of deadlock, since it is quite likely that
    302  *		the client procedure that we call will in turn call us
    303  *		to remove or adjust the monitor request.
    304  *		We therefore fork() a process to do the notifications.
    305  *		Note that the main HostInfo structure is in a mmap()
    306  *		region and so will be shared with the child, but the
    307  *		monList pointed to by the HostInfo is in normal memory.
    308  *		Hence if we read the monList before forking, we are
    309  *		protected from the parent servicing other requests
    310  *		that modify the list.
    311  */
    312 void   *
    313 sm_notify_1_svc(arg, req)
    314 	stat_chge *arg;
    315 	struct svc_req *req;
    316 {
    317 	struct timeval timeout = {20, 0};	/* 20 secs timeout */
    318 	CLIENT *cli;
    319 	static char dummy;
    320 	status tx_arg;		/* arg sent to callback procedure */
    321 	MonList *lp;
    322 	HostInfo *hp, h;
    323 	pid_t pid;
    324 
    325 	if (debug)
    326 		syslog(LOG_DEBUG, "notify from host %s, new state %d",
    327 		    arg->mon_name, arg->state);
    328 
    329 	hp = find_host(arg->mon_name, &h);
    330 	if (!hp) {
    331 		/* Never heard of this host - why is it notifying us? */
    332 		syslog(LOG_DEBUG, "Unsolicited notification from host %s",
    333 		    arg->mon_name);
    334 		return (&dummy);
    335 	}
    336 	lp = hp->monList;
    337 	if (!lp) /* We know this host, but have no outstanding requests. */
    338 		return (&dummy);
    339 
    340 	sync_file();
    341 	pid = fork();
    342 	if (pid == -1) {
    343 		syslog(LOG_ERR, "Unable to fork notify process - %s",
    344 		    strerror(errno));
    345 		return (FALSE);
    346 	}
    347 	if (pid)
    348 		return (&dummy); /* Parent returns */
    349 
    350 	while (lp) {
    351 		tx_arg.mon_name = arg->mon_name;
    352 		tx_arg.state = arg->state;
    353 		memcpy(tx_arg.priv, lp->notifyData, sizeof(tx_arg.priv));
    354 		cli = clnt_create(lp->notifyHost, lp->notifyProg,
    355 		    lp->notifyVers, "udp");
    356 		if (!cli)
    357 			syslog(LOG_ERR, "Failed to contact host %s%s",
    358 			    lp->notifyHost, clnt_spcreateerror(""));
    359 		else {
    360 			if (clnt_call(cli, lp->notifyProc, xdr_status, &tx_arg,
    361 			    xdr_void, &dummy, timeout) != RPC_SUCCESS)
    362 				syslog(LOG_ERR,
    363 				    "Failed to call rpc.statd client at host %s",
    364 				    lp->notifyHost);
    365 			clnt_destroy(cli);
    366 		}
    367 		lp = lp->next;
    368 	}
    369 
    370 	exit(0);		/* Child quits */
    371 }
    372