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rbootd.c revision 1.10 
      1 /*	$NetBSD: rbootd.c,v 1.10 1999/06/06 03:11:40 thorpej 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 1.10 1999/06/06 03:11:40 thorpej 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(__progname, 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 			syslog(LOG_NOTICE, "restarted (??)");
    162 			syslog(LOG_ERR, errmsg);
    163 			Exit(0);
    164 		}
    165 	}
    166 
    167 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
    168 
    169 	(void) signal(SIGHUP, ReConfig);
    170 	(void) signal(SIGINT, Exit);
    171 	(void) signal(SIGTERM, Exit);
    172 
    173 	/*
    174 	 *  Grab our host name and pid.
    175 	 */
    176 	if (gethostname(MyHost, sizeof MyHost) < 0) {
    177 		syslog(LOG_ERR, "gethostname: %m");
    178 		Exit(0);
    179 	}
    180 	MyHost[sizeof(MyHost) - 1] = '\0';
    181 
    182 	/*
    183 	 *  All boot files are relative to the boot directory, we might
    184 	 *  as well chdir() there to make life easier.
    185 	 */
    186 	if (chdir(BootDir) < 0) {
    187 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
    188 		Exit(0);
    189 	}
    190 
    191 	/*
    192 	 *  Initial configuration.
    193 	 */
    194 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
    195 	if (GetBootFiles() == 0)		/* get list of boot files */
    196 		Exit(0);
    197 	if (ParseConfig() == 0)			/* parse config file */
    198 		Exit(0);
    199 
    200 	/*
    201 	 *  Open and initialize a BPF device for the appropriate interface.
    202 	 *  If an error is encountered, a message is displayed and Exit()
    203 	 *  is called.
    204 	 */
    205 	fd = BpfOpen();
    206 
    207 	(void) sigsetmask(omask);		/* allow reconfig's */
    208 
    209 	/*
    210 	 *  Main loop: receive a packet, determine where it came from,
    211 	 *  and if we service this host, call routine to handle request.
    212 	 */
    213 	maxfds = fd + 1;
    214 	FD_ZERO(&rset);
    215 	FD_SET(fd, &rset);
    216 	for (;;) {
    217 		struct timeval timeout;
    218 		fd_set r;
    219 		int nsel;
    220 
    221 		r = rset;
    222 
    223 		if (RmpConns == NULL) {		/* timeout isnt necessary */
    224 			nsel = select(maxfds, &r, NULL, NULL, NULL);
    225 		} else {
    226 			timeout.tv_sec = RMP_TIMEOUT;
    227 			timeout.tv_usec = 0;
    228 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
    229 		}
    230 
    231 		if (nsel < 0) {
    232 			if (errno == EINTR)
    233 				continue;
    234 			syslog(LOG_ERR, "select: %m");
    235 			Exit(0);
    236 		} else if (nsel == 0) {		/* timeout */
    237 			DoTimeout();			/* clear stale conns */
    238 			continue;
    239 		}
    240 
    241 		if (FD_ISSET(fd, &r)) {
    242 			RMPCONN rconn;
    243 			CLIENT *client;
    244 			int doread = 1;
    245 
    246 			while (BpfRead(&rconn, doread)) {
    247 				doread = 0;
    248 
    249 				if (DbgFp != NULL)	/* display packet */
    250 					DispPkt(&rconn,DIR_RCVD);
    251 
    252 				omask = sigblock(sigmask(SIGHUP));
    253 
    254 				/*
    255 				 *  If we do not restrict service, set the
    256 				 *  client to NULL (ProcessPacket() handles
    257 				 *  this).  Otherwise, check that we can
    258 				 *  service this host; if not, log a message
    259 				 *  and ignore the packet.
    260 				 */
    261 				if (BootAny) {
    262 					client = NULL;
    263 				} else if ((client=FindClient(&rconn))==NULL) {
    264 					syslog(LOG_INFO,
    265 					       "%s: boot packet ignored",
    266 					       EnetStr(&rconn));
    267 					(void) sigsetmask(omask);
    268 					continue;
    269 				}
    270 
    271 				ProcessPacket(&rconn,client);
    272 
    273 				(void) sigsetmask(omask);
    274 			}
    275 		}
    276 	}
    277 }
    278 
    279 /*
    280 **  DoTimeout -- Free any connections that have timed out.
    281 **
    282 **	Parameters:
    283 **		None.
    284 **
    285 **	Returns:
    286 **		Nothing.
    287 **
    288 **	Side Effects:
    289 **		- Timed out connections in `RmpConns' will be freed.
    290 */
    291 void
    292 DoTimeout()
    293 {
    294 	RMPCONN *rtmp;
    295 	struct timeval now;
    296 
    297 	(void) gettimeofday(&now, (struct timezone *)0);
    298 
    299 	/*
    300 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
    301 	 *  since the last packet was sent, delete the connection.
    302 	 */
    303 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
    304 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
    305 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
    306 			       EnetStr(rtmp), rtmp->rmp.r_type);
    307 			RemoveConn(rtmp);
    308 		}
    309 }
    310 
    311 /*
    312 **  FindClient -- Find client associated with a packet.
    313 **
    314 **	Parameters:
    315 **		rconn - the new packet.
    316 **
    317 **	Returns:
    318 **		Pointer to client info if found, NULL otherwise.
    319 **
    320 **	Side Effects:
    321 **		None.
    322 **
    323 **	Warnings:
    324 **		- This routine must be called with SIGHUP blocked since
    325 **		  a reconfigure can invalidate the information returned.
    326 */
    327 
    328 CLIENT *
    329 FindClient(rconn)
    330 	RMPCONN *rconn;
    331 {
    332 	CLIENT *ctmp;
    333 
    334 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
    335 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
    336 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
    337 			break;
    338 
    339 	return(ctmp);
    340 }
    341 
    342 /*
    343 **  Exit -- Log an error message and exit.
    344 **
    345 **	Parameters:
    346 **		sig - caught signal (or zero if not dying on a signal).
    347 **
    348 **	Returns:
    349 **		Does not return.
    350 **
    351 **	Side Effects:
    352 **		- This process ceases to exist.
    353 */
    354 void
    355 Exit(sig)
    356 	int sig;
    357 {
    358 	if (sig > 0)
    359 		syslog(LOG_ERR, "going down on signal %d", sig);
    360 	else
    361 		syslog(LOG_ERR, "going down with fatal error");
    362 	BpfClose();
    363 	exit(1);
    364 }
    365 
    366 /*
    367 **  ReConfig -- Get new list of boot files and reread config files.
    368 **
    369 **	Parameters:
    370 **		None.
    371 **
    372 **	Returns:
    373 **		Nothing.
    374 **
    375 **	Side Effects:
    376 **		- All active connections are dropped.
    377 **		- List of boot-able files is changed.
    378 **		- List of clients is changed.
    379 **
    380 **	Warnings:
    381 **		- This routine must be called with SIGHUP blocked.
    382 */
    383 void
    384 ReConfig(signo)
    385 	int signo;
    386 {
    387 	syslog(LOG_NOTICE, "reconfiguring boot server");
    388 
    389 	FreeConns();
    390 
    391 	if (GetBootFiles() == 0)
    392 		Exit(0);
    393 
    394 	if (ParseConfig() == 0)
    395 		Exit(0);
    396 }
    397 
    398 /*
    399 **  DebugOff -- Turn off debugging.
    400 **
    401 **	Parameters:
    402 **		None.
    403 **
    404 **	Returns:
    405 **		Nothing.
    406 **
    407 **	Side Effects:
    408 **		- Debug file is closed.
    409 */
    410 void
    411 DebugOff(signo)
    412 	int signo;
    413 {
    414 	if (DbgFp != NULL)
    415 		(void) fclose(DbgFp);
    416 
    417 	DbgFp = NULL;
    418 }
    419 
    420 /*
    421 **  DebugOn -- Turn on debugging.
    422 **
    423 **	Parameters:
    424 **		None.
    425 **
    426 **	Returns:
    427 **		Nothing.
    428 **
    429 **	Side Effects:
    430 **		- Debug file is opened/truncated if not already opened,
    431 **		  otherwise do nothing.
    432 */
    433 void
    434 DebugOn(signo)
    435 	int signo;
    436 {
    437 	if (DbgFp == NULL) {
    438 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
    439 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
    440 	}
    441 }
    442