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rbootd.c revision 1.16
      1 /*	$NetBSD: rbootd.c,v 1.16 2002/09/19 03:04:13 mycroft 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 1.16 2002/09/19 03:04:13 mycroft Exp $");
     61 #endif
     62 #endif /* not lint */
     63 
     64 #include <sys/param.h>
     65 #include <sys/time.h>
     66 #include <sys/poll.h>
     67 #include <ctype.h>
     68 #include <err.h>
     69 #include <errno.h>
     70 #include <fcntl.h>
     71 #include <signal.h>
     72 #include <stdio.h>
     73 #include <stdlib.h>
     74 #include <string.h>
     75 #include <syslog.h>
     76 #include <unistd.h>
     77 #include <util.h>
     78 #include "defs.h"
     79 
     80 int	main __P((int, char *[]));
     81 
     82 int
     83 main(argc, argv)
     84 	int argc;
     85 	char *argv[];
     86 {
     87 	int c, fd, omask;
     88 	struct pollfd set[1];
     89 
     90 	/*
     91 	 *  Close any open file descriptors.
     92 	 *  Temporarily leave stdin & stdout open for `-d',
     93 	 *  and stderr open for any pre-syslog error messages.
     94 	 */
     95 	{
     96 		int i, nfds = getdtablesize();
     97 
     98 		for (i = 0; i < nfds; i++)
     99 			if (i != STDIN_FILENO && i != STDOUT_FILENO &&
    100 			    i != STDERR_FILENO)
    101 				(void) close(i);
    102 	}
    103 
    104 	/*
    105 	 *  Parse any arguments.
    106 	 */
    107 	while ((c = getopt(argc, argv, "adi:")) != -1)
    108 		switch(c) {
    109 		    case 'a':
    110 			BootAny++;
    111 			break;
    112 		    case 'd':
    113 			DebugFlg++;
    114 			break;
    115 		    case 'i':
    116 			IntfName = optarg;
    117 			break;
    118 		}
    119 	for (; optind < argc; optind++) {
    120 		if (ConfigFile == NULL)
    121 			ConfigFile = argv[optind];
    122 		else {
    123 			warnx("too many config files (`%s' ignored)",
    124 			    argv[optind]);
    125 		}
    126 	}
    127 
    128 	if (ConfigFile == NULL)			/* use default config file */
    129 		ConfigFile = DfltConfig;
    130 
    131 	if (DebugFlg) {
    132 		DbgFp = stdout;				/* output to stdout */
    133 
    134 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
    135 		(void) signal(SIGUSR2, SIG_IGN);
    136 		(void) fclose(stderr);			/* finished with it */
    137 	} else {
    138 		if (daemon(0, 0))
    139 			err(1, "can't detach from terminal");
    140 		pidfile(NULL);
    141 
    142 		(void) signal(SIGUSR1, DebugOn);
    143 		(void) signal(SIGUSR2, DebugOff);
    144 	}
    145 
    146 	openlog("rbootd", LOG_PID, LOG_DAEMON);
    147 
    148 	/*
    149 	 *  If no interface was specified, get one now.
    150 	 *
    151 	 *  This is convoluted because we want to get the default interface
    152 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
    153 	 *  runs into an error, it will return a syslog-able error message
    154 	 *  (in `errmsg') which will be displayed here.
    155 	 */
    156 	if (IntfName == NULL) {
    157 		char *errmsg;
    158 
    159 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
    160 			/* backslash to avoid trigraph ??) */
    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 	set[0].fd = fd;
    214 	set[0].events = POLLIN;
    215 	for (;;) {
    216 		int nsel;
    217 
    218 		nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
    219 
    220 		if (nsel < 0) {
    221 			if (errno == EINTR)
    222 				continue;
    223 			syslog(LOG_ERR, "poll: %m");
    224 			Exit(0);
    225 		} else if (nsel == 0) {		/* timeout */
    226 			DoTimeout();			/* clear stale conns */
    227 			continue;
    228 		}
    229 
    230 		if (set[0].revents & POLLIN) {
    231 			RMPCONN rconn;
    232 			CLIENT *client;
    233 			int doread = 1;
    234 
    235 			while (BpfRead(&rconn, doread)) {
    236 				doread = 0;
    237 
    238 				if (DbgFp != NULL)	/* display packet */
    239 					DispPkt(&rconn,DIR_RCVD);
    240 
    241 				omask = sigblock(sigmask(SIGHUP));
    242 
    243 				/*
    244 				 *  If we do not restrict service, set the
    245 				 *  client to NULL (ProcessPacket() handles
    246 				 *  this).  Otherwise, check that we can
    247 				 *  service this host; if not, log a message
    248 				 *  and ignore the packet.
    249 				 */
    250 				if (BootAny) {
    251 					client = NULL;
    252 				} else if ((client=FindClient(&rconn))==NULL) {
    253 					syslog(LOG_INFO,
    254 					       "%s: boot packet ignored",
    255 					       EnetStr(&rconn));
    256 					(void) sigsetmask(omask);
    257 					continue;
    258 				}
    259 
    260 				ProcessPacket(&rconn,client);
    261 
    262 				(void) sigsetmask(omask);
    263 			}
    264 		}
    265 	}
    266 }
    267 
    268 /*
    269 **  DoTimeout -- Free any connections that have timed out.
    270 **
    271 **	Parameters:
    272 **		None.
    273 **
    274 **	Returns:
    275 **		Nothing.
    276 **
    277 **	Side Effects:
    278 **		- Timed out connections in `RmpConns' will be freed.
    279 */
    280 void
    281 DoTimeout()
    282 {
    283 	RMPCONN *rtmp;
    284 	struct timeval now;
    285 
    286 	(void) gettimeofday(&now, (struct timezone *)0);
    287 
    288 	/*
    289 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
    290 	 *  since the last packet was sent, delete the connection.
    291 	 */
    292 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
    293 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
    294 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
    295 			       EnetStr(rtmp), rtmp->rmp.r_type);
    296 			RemoveConn(rtmp);
    297 		}
    298 }
    299 
    300 /*
    301 **  FindClient -- Find client associated with a packet.
    302 **
    303 **	Parameters:
    304 **		rconn - the new packet.
    305 **
    306 **	Returns:
    307 **		Pointer to client info if found, NULL otherwise.
    308 **
    309 **	Side Effects:
    310 **		None.
    311 **
    312 **	Warnings:
    313 **		- This routine must be called with SIGHUP blocked since
    314 **		  a reconfigure can invalidate the information returned.
    315 */
    316 
    317 CLIENT *
    318 FindClient(rconn)
    319 	RMPCONN *rconn;
    320 {
    321 	CLIENT *ctmp;
    322 
    323 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
    324 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
    325 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
    326 			break;
    327 
    328 	return(ctmp);
    329 }
    330 
    331 /*
    332 **  Exit -- Log an error message and exit.
    333 **
    334 **	Parameters:
    335 **		sig - caught signal (or zero if not dying on a signal).
    336 **
    337 **	Returns:
    338 **		Does not return.
    339 **
    340 **	Side Effects:
    341 **		- This process ceases to exist.
    342 */
    343 void
    344 Exit(sig)
    345 	int sig;
    346 {
    347 	if (sig > 0)
    348 		syslog(LOG_ERR, "going down on signal %d", sig);
    349 	else
    350 		syslog(LOG_ERR, "going down with fatal error");
    351 	BpfClose();
    352 	exit(1);
    353 }
    354 
    355 /*
    356 **  ReConfig -- Get new list of boot files and reread config files.
    357 **
    358 **	Parameters:
    359 **		None.
    360 **
    361 **	Returns:
    362 **		Nothing.
    363 **
    364 **	Side Effects:
    365 **		- All active connections are dropped.
    366 **		- List of boot-able files is changed.
    367 **		- List of clients is changed.
    368 **
    369 **	Warnings:
    370 **		- This routine must be called with SIGHUP blocked.
    371 */
    372 void
    373 ReConfig(signo)
    374 	int signo;
    375 {
    376 	syslog(LOG_NOTICE, "reconfiguring boot server");
    377 
    378 	FreeConns();
    379 
    380 	if (GetBootFiles() == 0)
    381 		Exit(0);
    382 
    383 	if (ParseConfig() == 0)
    384 		Exit(0);
    385 }
    386 
    387 /*
    388 **  DebugOff -- Turn off debugging.
    389 **
    390 **	Parameters:
    391 **		None.
    392 **
    393 **	Returns:
    394 **		Nothing.
    395 **
    396 **	Side Effects:
    397 **		- Debug file is closed.
    398 */
    399 void
    400 DebugOff(signo)
    401 	int signo;
    402 {
    403 	if (DbgFp != NULL)
    404 		(void) fclose(DbgFp);
    405 
    406 	DbgFp = NULL;
    407 }
    408 
    409 /*
    410 **  DebugOn -- Turn on debugging.
    411 **
    412 **	Parameters:
    413 **		None.
    414 **
    415 **	Returns:
    416 **		Nothing.
    417 **
    418 **	Side Effects:
    419 **		- Debug file is opened/truncated if not already opened,
    420 **		  otherwise do nothing.
    421 */
    422 void
    423 DebugOn(signo)
    424 	int signo;
    425 {
    426 	if (DbgFp == NULL) {
    427 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
    428 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
    429 	}
    430 }
    431