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rbootd.c revision 1.13 
      1 /*	$NetBSD: rbootd.c,v 1.13 2001/01/16 02:36:29 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1992 The University of Utah and the Center
      5  *	for Software Science (CSS).
      6  * Copyright (c) 1992, 1993
      7  *	The Regents of the University of California.  All rights reserved.
      8  *
      9  * This code is derived from software contributed to Berkeley by
     10  * the Center for Software Science of the University of Utah Computer
     11  * Science Department.  CSS requests users of this software to return
     12  * to css-dist (at) cs.utah.edu any improvements that they make and grant
     13  * CSS redistribution rights.
     14  *
     15  * Redistribution and use in source and binary forms, with or without
     16  * modification, are permitted provided that the following conditions
     17  * are met:
     18  * 1. Redistributions of source code must retain the above copyright
     19  *    notice, this list of conditions and the following disclaimer.
     20  * 2. Redistributions in binary form must reproduce the above copyright
     21  *    notice, this list of conditions and the following disclaimer in the
     22  *    documentation and/or other materials provided with the distribution.
     23  * 3. All advertising materials mentioning features or use of this software
     24  *    must display the following acknowledgement:
     25  *	This product includes software developed by the University of
     26  *	California, Berkeley and its contributors.
     27  * 4. Neither the name of the University nor the names of its contributors
     28  *    may be used to endorse or promote products derived from this software
     29  *    without specific prior written permission.
     30  *
     31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     41  * SUCH DAMAGE.
     42  *
     43  *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
     44  *
     45  * From: Utah Hdr: rbootd.c 3.1 92/07/06
     46  * Author: Jeff Forys, University of Utah CSS
     47  */
     48 
     49 #include <sys/cdefs.h>
     50 #ifndef lint
     51 __COPYRIGHT(
     52 "@(#) Copyright (c) 1992, 1993\n\
     53 	The Regents of the University of California.  All rights reserved.\n");
     54 #endif /* not lint */
     55 
     56 #ifndef lint
     57 #if 0
     58 static char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
     59 #else
     60 __RCSID("$NetBSD: rbootd.c,v 1.13 2001/01/16 02:36:29 cgd Exp $");
     61 #endif
     62 #endif /* not lint */
     63 
     64 #include <sys/param.h>
     65 #include <sys/time.h>
     66 #include <ctype.h>
     67 #include <err.h>
     68 #include <errno.h>
     69 #include <fcntl.h>
     70 #include <signal.h>
     71 #include <stdio.h>
     72 #include <stdlib.h>
     73 #include <string.h>
     74 #include <syslog.h>
     75 #include <unistd.h>
     76 #include <util.h>
     77 #include "defs.h"
     78 
     79 int	main __P((int, char *[]));
     80 
     81 extern	char *__progname;	/* from crt0.o */
     82 
     83 int
     84 main(argc, argv)
     85 	int argc;
     86 	char *argv[];
     87 {
     88 	int c, fd, omask, maxfds;
     89 	fd_set rset;
     90 
     91 	/*
     92 	 *  Close any open file descriptors.
     93 	 *  Temporarily leave stdin & stdout open for `-d',
     94 	 *  and stderr open for any pre-syslog error messages.
     95 	 */
     96 	{
     97 		int i, nfds = getdtablesize();
     98 
     99 		for (i = 0; i < nfds; i++)
    100 			if (i != fileno(stdin) && i != fileno(stdout) &&
    101 			    i != fileno(stderr))
    102 				(void) close(i);
    103 	}
    104 
    105 	/*
    106 	 *  Parse any arguments.
    107 	 */
    108 	while ((c = getopt(argc, argv, "adi:")) != -1)
    109 		switch(c) {
    110 		    case 'a':
    111 			BootAny++;
    112 			break;
    113 		    case 'd':
    114 			DebugFlg++;
    115 			break;
    116 		    case 'i':
    117 			IntfName = optarg;
    118 			break;
    119 		}
    120 	for (; optind < argc; optind++) {
    121 		if (ConfigFile == NULL)
    122 			ConfigFile = argv[optind];
    123 		else {
    124 			warnx("too many config files (`%s' ignored)\n",
    125 			    argv[optind]);
    126 		}
    127 	}
    128 
    129 	if (ConfigFile == NULL)			/* use default config file */
    130 		ConfigFile = DfltConfig;
    131 
    132 	if (DebugFlg) {
    133 		DbgFp = stdout;				/* output to stdout */
    134 
    135 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
    136 		(void) signal(SIGUSR2, SIG_IGN);
    137 		(void) fclose(stderr);			/* finished with it */
    138 	} else {
    139 		if (daemon(0, 0))
    140 			err(1, "can't detach from terminal");
    141 		pidfile(NULL);
    142 
    143 		(void) signal(SIGUSR1, DebugOn);
    144 		(void) signal(SIGUSR2, DebugOff);
    145 	}
    146 
    147 	openlog("rbootd", LOG_PID, LOG_DAEMON);
    148 
    149 	/*
    150 	 *  If no interface was specified, get one now.
    151 	 *
    152 	 *  This is convoluted because we want to get the default interface
    153 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
    154 	 *  runs into an error, it will return a syslog-able error message
    155 	 *  (in `errmsg') which will be displayed here.
    156 	 */
    157 	if (IntfName == NULL) {
    158 		char *errmsg;
    159 
    160 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
    161 			/* backslash to avoid trigraph ??) */
    162 			syslog(LOG_NOTICE, "restarted (?\?)");
    163 			syslog(LOG_ERR, errmsg);
    164 			Exit(0);
    165 		}
    166 	}
    167 
    168 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
    169 
    170 	(void) signal(SIGHUP, ReConfig);
    171 	(void) signal(SIGINT, Exit);
    172 	(void) signal(SIGTERM, Exit);
    173 
    174 	/*
    175 	 *  Grab our host name and pid.
    176 	 */
    177 	if (gethostname(MyHost, sizeof MyHost) < 0) {
    178 		syslog(LOG_ERR, "gethostname: %m");
    179 		Exit(0);
    180 	}
    181 	MyHost[sizeof(MyHost) - 1] = '\0';
    182 
    183 	/*
    184 	 *  All boot files are relative to the boot directory, we might
    185 	 *  as well chdir() there to make life easier.
    186 	 */
    187 	if (chdir(BootDir) < 0) {
    188 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
    189 		Exit(0);
    190 	}
    191 
    192 	/*
    193 	 *  Initial configuration.
    194 	 */
    195 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
    196 	if (GetBootFiles() == 0)		/* get list of boot files */
    197 		Exit(0);
    198 	if (ParseConfig() == 0)			/* parse config file */
    199 		Exit(0);
    200 
    201 	/*
    202 	 *  Open and initialize a BPF device for the appropriate interface.
    203 	 *  If an error is encountered, a message is displayed and Exit()
    204 	 *  is called.
    205 	 */
    206 	fd = BpfOpen();
    207 
    208 	(void) sigsetmask(omask);		/* allow reconfig's */
    209 
    210 	/*
    211 	 *  Main loop: receive a packet, determine where it came from,
    212 	 *  and if we service this host, call routine to handle request.
    213 	 */
    214 	maxfds = fd + 1;
    215 	FD_ZERO(&rset);
    216 	FD_SET(fd, &rset);
    217 	for (;;) {
    218 		struct timeval timeout;
    219 		fd_set r;
    220 		int nsel;
    221 
    222 		r = rset;
    223 
    224 		if (RmpConns == NULL) {		/* timeout isnt necessary */
    225 			nsel = select(maxfds, &r, NULL, NULL, NULL);
    226 		} else {
    227 			timeout.tv_sec = RMP_TIMEOUT;
    228 			timeout.tv_usec = 0;
    229 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
    230 		}
    231 
    232 		if (nsel < 0) {
    233 			if (errno == EINTR)
    234 				continue;
    235 			syslog(LOG_ERR, "select: %m");
    236 			Exit(0);
    237 		} else if (nsel == 0) {		/* timeout */
    238 			DoTimeout();			/* clear stale conns */
    239 			continue;
    240 		}
    241 
    242 		if (FD_ISSET(fd, &r)) {
    243 			RMPCONN rconn;
    244 			CLIENT *client;
    245 			int doread = 1;
    246 
    247 			while (BpfRead(&rconn, doread)) {
    248 				doread = 0;
    249 
    250 				if (DbgFp != NULL)	/* display packet */
    251 					DispPkt(&rconn,DIR_RCVD);
    252 
    253 				omask = sigblock(sigmask(SIGHUP));
    254 
    255 				/*
    256 				 *  If we do not restrict service, set the
    257 				 *  client to NULL (ProcessPacket() handles
    258 				 *  this).  Otherwise, check that we can
    259 				 *  service this host; if not, log a message
    260 				 *  and ignore the packet.
    261 				 */
    262 				if (BootAny) {
    263 					client = NULL;
    264 				} else if ((client=FindClient(&rconn))==NULL) {
    265 					syslog(LOG_INFO,
    266 					       "%s: boot packet ignored",
    267 					       EnetStr(&rconn));
    268 					(void) sigsetmask(omask);
    269 					continue;
    270 				}
    271 
    272 				ProcessPacket(&rconn,client);
    273 
    274 				(void) sigsetmask(omask);
    275 			}
    276 		}
    277 	}
    278 }
    279 
    280 /*
    281 **  DoTimeout -- Free any connections that have timed out.
    282 **
    283 **	Parameters:
    284 **		None.
    285 **
    286 **	Returns:
    287 **		Nothing.
    288 **
    289 **	Side Effects:
    290 **		- Timed out connections in `RmpConns' will be freed.
    291 */
    292 void
    293 DoTimeout()
    294 {
    295 	RMPCONN *rtmp;
    296 	struct timeval now;
    297 
    298 	(void) gettimeofday(&now, (struct timezone *)0);
    299 
    300 	/*
    301 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
    302 	 *  since the last packet was sent, delete the connection.
    303 	 */
    304 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
    305 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
    306 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
    307 			       EnetStr(rtmp), rtmp->rmp.r_type);
    308 			RemoveConn(rtmp);
    309 		}
    310 }
    311 
    312 /*
    313 **  FindClient -- Find client associated with a packet.
    314 **
    315 **	Parameters:
    316 **		rconn - the new packet.
    317 **
    318 **	Returns:
    319 **		Pointer to client info if found, NULL otherwise.
    320 **
    321 **	Side Effects:
    322 **		None.
    323 **
    324 **	Warnings:
    325 **		- This routine must be called with SIGHUP blocked since
    326 **		  a reconfigure can invalidate the information returned.
    327 */
    328 
    329 CLIENT *
    330 FindClient(rconn)
    331 	RMPCONN *rconn;
    332 {
    333 	CLIENT *ctmp;
    334 
    335 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
    336 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
    337 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
    338 			break;
    339 
    340 	return(ctmp);
    341 }
    342 
    343 /*
    344 **  Exit -- Log an error message and exit.
    345 **
    346 **	Parameters:
    347 **		sig - caught signal (or zero if not dying on a signal).
    348 **
    349 **	Returns:
    350 **		Does not return.
    351 **
    352 **	Side Effects:
    353 **		- This process ceases to exist.
    354 */
    355 void
    356 Exit(sig)
    357 	int sig;
    358 {
    359 	if (sig > 0)
    360 		syslog(LOG_ERR, "going down on signal %d", sig);
    361 	else
    362 		syslog(LOG_ERR, "going down with fatal error");
    363 	BpfClose();
    364 	exit(1);
    365 }
    366 
    367 /*
    368 **  ReConfig -- Get new list of boot files and reread config files.
    369 **
    370 **	Parameters:
    371 **		None.
    372 **
    373 **	Returns:
    374 **		Nothing.
    375 **
    376 **	Side Effects:
    377 **		- All active connections are dropped.
    378 **		- List of boot-able files is changed.
    379 **		- List of clients is changed.
    380 **
    381 **	Warnings:
    382 **		- This routine must be called with SIGHUP blocked.
    383 */
    384 void
    385 ReConfig(signo)
    386 	int signo;
    387 {
    388 	syslog(LOG_NOTICE, "reconfiguring boot server");
    389 
    390 	FreeConns();
    391 
    392 	if (GetBootFiles() == 0)
    393 		Exit(0);
    394 
    395 	if (ParseConfig() == 0)
    396 		Exit(0);
    397 }
    398 
    399 /*
    400 **  DebugOff -- Turn off debugging.
    401 **
    402 **	Parameters:
    403 **		None.
    404 **
    405 **	Returns:
    406 **		Nothing.
    407 **
    408 **	Side Effects:
    409 **		- Debug file is closed.
    410 */
    411 void
    412 DebugOff(signo)
    413 	int signo;
    414 {
    415 	if (DbgFp != NULL)
    416 		(void) fclose(DbgFp);
    417 
    418 	DbgFp = NULL;
    419 }
    420 
    421 /*
    422 **  DebugOn -- Turn on debugging.
    423 **
    424 **	Parameters:
    425 **		None.
    426 **
    427 **	Returns:
    428 **		Nothing.
    429 **
    430 **	Side Effects:
    431 **		- Debug file is opened/truncated if not already opened,
    432 **		  otherwise do nothing.
    433 */
    434 void
    435 DebugOn(signo)
    436 	int signo;
    437 {
    438 	if (DbgFp == NULL) {
    439 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
    440 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
    441 	}
    442 }
    443