xref: /netbsd-src/usr.sbin/rbootd/rbootd.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: rbootd.c,v 1.19 2003/08/07 11:25:41 agc Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * the Center for Software Science of the University of Utah Computer
9  * Science Department.  CSS requests users of this software to return
10  * to css-dist@cs.utah.edu any improvements that they make and grant
11  * CSS redistribution rights.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
38  *
39  * From: Utah Hdr: rbootd.c 3.1 92/07/06
40  * Author: Jeff Forys, University of Utah CSS
41  */
42 
43 /*
44  * Copyright (c) 1988, 1992 The University of Utah and the Center
45  *	for Software Science (CSS).
46  *
47  * This code is derived from software contributed to Berkeley by
48  * the Center for Software Science of the University of Utah Computer
49  * Science Department.  CSS requests users of this software to return
50  * to css-dist@cs.utah.edu any improvements that they make and grant
51  * CSS redistribution rights.
52  *
53  * Redistribution and use in source and binary forms, with or without
54  * modification, are permitted provided that the following conditions
55  * are met:
56  * 1. Redistributions of source code must retain the above copyright
57  *    notice, this list of conditions and the following disclaimer.
58  * 2. Redistributions in binary form must reproduce the above copyright
59  *    notice, this list of conditions and the following disclaimer in the
60  *    documentation and/or other materials provided with the distribution.
61  * 3. All advertising materials mentioning features or use of this software
62  *    must display the following acknowledgement:
63  *	This product includes software developed by the University of
64  *	California, Berkeley and its contributors.
65  * 4. Neither the name of the University nor the names of its contributors
66  *    may be used to endorse or promote products derived from this software
67  *    without specific prior written permission.
68  *
69  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
70  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
71  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
72  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
73  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
74  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
75  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
76  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
77  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
78  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
79  * SUCH DAMAGE.
80  *
81  *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
82  *
83  * From: Utah Hdr: rbootd.c 3.1 92/07/06
84  * Author: Jeff Forys, University of Utah CSS
85  */
86 
87 #include <sys/cdefs.h>
88 #ifndef lint
89 __COPYRIGHT(
90 "@(#) Copyright (c) 1992, 1993\n\
91 	The Regents of the University of California.  All rights reserved.\n");
92 #endif /* not lint */
93 
94 #ifndef lint
95 #if 0
96 static char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
97 #else
98 __RCSID("$NetBSD: rbootd.c,v 1.19 2003/08/07 11:25:41 agc Exp $");
99 #endif
100 #endif /* not lint */
101 
102 #include <sys/param.h>
103 #include <sys/time.h>
104 #include <poll.h>
105 #include <ctype.h>
106 #include <err.h>
107 #include <errno.h>
108 #include <fcntl.h>
109 #include <signal.h>
110 #include <stdio.h>
111 #include <stdlib.h>
112 #include <string.h>
113 #include <syslog.h>
114 #include <unistd.h>
115 #include <util.h>
116 #include "defs.h"
117 
118 int	main __P((int, char *[]));
119 
120 int
121 main(argc, argv)
122 	int argc;
123 	char *argv[];
124 {
125 	int c, fd, omask;
126 	struct pollfd set[1];
127 
128 	/*
129 	 *  Close any open file descriptors.
130 	 *  Temporarily leave stdin & stdout open for `-d',
131 	 *  and stderr open for any pre-syslog error messages.
132 	 */
133 	{
134 		int i, nfds = getdtablesize();
135 
136 		for (i = 0; i < nfds; i++)
137 			if (i != STDIN_FILENO && i != STDOUT_FILENO &&
138 			    i != STDERR_FILENO)
139 				(void) close(i);
140 	}
141 
142 	/*
143 	 *  Parse any arguments.
144 	 */
145 	while ((c = getopt(argc, argv, "adi:")) != -1)
146 		switch(c) {
147 		    case 'a':
148 			BootAny++;
149 			break;
150 		    case 'd':
151 			DebugFlg++;
152 			break;
153 		    case 'i':
154 			IntfName = optarg;
155 			break;
156 		}
157 	for (; optind < argc; optind++) {
158 		if (ConfigFile == NULL)
159 			ConfigFile = argv[optind];
160 		else {
161 			warnx("too many config files (`%s' ignored)",
162 			    argv[optind]);
163 		}
164 	}
165 
166 	if (ConfigFile == NULL)			/* use default config file */
167 		ConfigFile = DfltConfig;
168 
169 	if (DebugFlg) {
170 		DbgFp = stdout;				/* output to stdout */
171 
172 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
173 		(void) signal(SIGUSR2, SIG_IGN);
174 		(void) fclose(stderr);			/* finished with it */
175 	} else {
176 		if (daemon(0, 0))
177 			err(1, "can't detach from terminal");
178 		pidfile(NULL);
179 
180 		(void) signal(SIGUSR1, DebugOn);
181 		(void) signal(SIGUSR2, DebugOff);
182 	}
183 
184 	openlog("rbootd", LOG_PID, LOG_DAEMON);
185 
186 	/*
187 	 *  If no interface was specified, get one now.
188 	 *
189 	 *  This is convoluted because we want to get the default interface
190 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
191 	 *  runs into an error, it will return a syslog-able error message
192 	 *  (in `errmsg') which will be displayed here.
193 	 */
194 	if (IntfName == NULL) {
195 		char *errmsg;
196 
197 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
198 			/* backslash to avoid trigraph ??) */
199 			syslog(LOG_NOTICE, "restarted (?\?)");
200 			syslog(LOG_ERR, errmsg);
201 			Exit(0);
202 		}
203 	}
204 
205 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
206 
207 	(void) signal(SIGHUP, ReConfig);
208 	(void) signal(SIGINT, Exit);
209 	(void) signal(SIGTERM, Exit);
210 
211 	/*
212 	 *  Grab our host name and pid.
213 	 */
214 	if (gethostname(MyHost, sizeof MyHost) < 0) {
215 		syslog(LOG_ERR, "gethostname: %m");
216 		Exit(0);
217 	}
218 	MyHost[sizeof(MyHost) - 1] = '\0';
219 
220 	/*
221 	 *  All boot files are relative to the boot directory, we might
222 	 *  as well chdir() there to make life easier.
223 	 */
224 	if (chdir(BootDir) < 0) {
225 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
226 		Exit(0);
227 	}
228 
229 	/*
230 	 *  Initial configuration.
231 	 */
232 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
233 	if (GetBootFiles() == 0)		/* get list of boot files */
234 		Exit(0);
235 	if (ParseConfig() == 0)			/* parse config file */
236 		Exit(0);
237 
238 	/*
239 	 *  Open and initialize a BPF device for the appropriate interface.
240 	 *  If an error is encountered, a message is displayed and Exit()
241 	 *  is called.
242 	 */
243 	fd = BpfOpen();
244 
245 	(void) sigsetmask(omask);		/* allow reconfig's */
246 
247 	/*
248 	 *  Main loop: receive a packet, determine where it came from,
249 	 *  and if we service this host, call routine to handle request.
250 	 */
251 	set[0].fd = fd;
252 	set[0].events = POLLIN;
253 	for (;;) {
254 		int nsel;
255 
256 		nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
257 
258 		if (nsel < 0) {
259 			if (errno == EINTR)
260 				continue;
261 			syslog(LOG_ERR, "poll: %m");
262 			Exit(0);
263 		} else if (nsel == 0) {		/* timeout */
264 			DoTimeout();			/* clear stale conns */
265 			continue;
266 		}
267 
268 		if (set[0].revents & POLLIN) {
269 			RMPCONN rconn;
270 			CLIENT *client;
271 			int doread = 1;
272 
273 			while (BpfRead(&rconn, doread)) {
274 				doread = 0;
275 
276 				if (DbgFp != NULL)	/* display packet */
277 					DispPkt(&rconn,DIR_RCVD);
278 
279 				omask = sigblock(sigmask(SIGHUP));
280 
281 				/*
282 				 *  If we do not restrict service, set the
283 				 *  client to NULL (ProcessPacket() handles
284 				 *  this).  Otherwise, check that we can
285 				 *  service this host; if not, log a message
286 				 *  and ignore the packet.
287 				 */
288 				if (BootAny) {
289 					client = NULL;
290 				} else if ((client=FindClient(&rconn))==NULL) {
291 					syslog(LOG_INFO,
292 					       "%s: boot packet ignored",
293 					       EnetStr(&rconn));
294 					(void) sigsetmask(omask);
295 					continue;
296 				}
297 
298 				ProcessPacket(&rconn,client);
299 
300 				(void) sigsetmask(omask);
301 			}
302 		}
303 	}
304 }
305 
306 /*
307 **  DoTimeout -- Free any connections that have timed out.
308 **
309 **	Parameters:
310 **		None.
311 **
312 **	Returns:
313 **		Nothing.
314 **
315 **	Side Effects:
316 **		- Timed out connections in `RmpConns' will be freed.
317 */
318 void
319 DoTimeout()
320 {
321 	RMPCONN *rtmp;
322 	struct timeval now;
323 
324 	(void) gettimeofday(&now, (struct timezone *)0);
325 
326 	/*
327 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
328 	 *  since the last packet was sent, delete the connection.
329 	 */
330 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
331 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
332 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
333 			       EnetStr(rtmp), rtmp->rmp.r_type);
334 			RemoveConn(rtmp);
335 		}
336 }
337 
338 /*
339 **  FindClient -- Find client associated with a packet.
340 **
341 **	Parameters:
342 **		rconn - the new packet.
343 **
344 **	Returns:
345 **		Pointer to client info if found, NULL otherwise.
346 **
347 **	Side Effects:
348 **		None.
349 **
350 **	Warnings:
351 **		- This routine must be called with SIGHUP blocked since
352 **		  a reconfigure can invalidate the information returned.
353 */
354 
355 CLIENT *
356 FindClient(rconn)
357 	RMPCONN *rconn;
358 {
359 	CLIENT *ctmp;
360 
361 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
362 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
363 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
364 			break;
365 
366 	return(ctmp);
367 }
368 
369 /*
370 **  Exit -- Log an error message and exit.
371 **
372 **	Parameters:
373 **		sig - caught signal (or zero if not dying on a signal).
374 **
375 **	Returns:
376 **		Does not return.
377 **
378 **	Side Effects:
379 **		- This process ceases to exist.
380 */
381 void
382 Exit(sig)
383 	int sig;
384 {
385 	if (sig > 0)
386 		syslog(LOG_ERR, "going down on signal %d", sig);
387 	else
388 		syslog(LOG_ERR, "going down with fatal error");
389 	BpfClose();
390 	exit(1);
391 }
392 
393 /*
394 **  ReConfig -- Get new list of boot files and reread config files.
395 **
396 **	Parameters:
397 **		None.
398 **
399 **	Returns:
400 **		Nothing.
401 **
402 **	Side Effects:
403 **		- All active connections are dropped.
404 **		- List of boot-able files is changed.
405 **		- List of clients is changed.
406 **
407 **	Warnings:
408 **		- This routine must be called with SIGHUP blocked.
409 */
410 void
411 ReConfig(signo)
412 	int signo;
413 {
414 	syslog(LOG_NOTICE, "reconfiguring boot server");
415 
416 	FreeConns();
417 
418 	if (GetBootFiles() == 0)
419 		Exit(0);
420 
421 	if (ParseConfig() == 0)
422 		Exit(0);
423 }
424 
425 /*
426 **  DebugOff -- Turn off debugging.
427 **
428 **	Parameters:
429 **		None.
430 **
431 **	Returns:
432 **		Nothing.
433 **
434 **	Side Effects:
435 **		- Debug file is closed.
436 */
437 void
438 DebugOff(signo)
439 	int signo;
440 {
441 	if (DbgFp != NULL)
442 		(void) fclose(DbgFp);
443 
444 	DbgFp = NULL;
445 }
446 
447 /*
448 **  DebugOn -- Turn on debugging.
449 **
450 **	Parameters:
451 **		None.
452 **
453 **	Returns:
454 **		Nothing.
455 **
456 **	Side Effects:
457 **		- Debug file is opened/truncated if not already opened,
458 **		  otherwise do nothing.
459 */
460 void
461 DebugOn(signo)
462 	int signo;
463 {
464 	if (DbgFp == NULL) {
465 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
466 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
467 	}
468 }
469