xref: /netbsd-src/usr.sbin/rbootd/rbootd.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: rbootd.c,v 1.20 2007/02/21 20:57:55 hubertf 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 1.20 2007/02/21 20:57:55 hubertf Exp $");
99 #endif
100 #endif /* not lint */
101 
102 #include <sys/param.h>
103 #include <sys/time.h>
104 #include <poll.h>
105 #include <err.h>
106 #include <errno.h>
107 #include <fcntl.h>
108 #include <signal.h>
109 #include <stdio.h>
110 #include <stdlib.h>
111 #include <string.h>
112 #include <syslog.h>
113 #include <unistd.h>
114 #include <util.h>
115 #include "defs.h"
116 
117 int	main (int, char *[]);
118 
119 int
120 main(int argc, char *argv[])
121 {
122 	int c, fd, omask;
123 	struct pollfd set[1];
124 
125 	/*
126 	 *  Close any open file descriptors.
127 	 *  Temporarily leave stdin & stdout open for `-d',
128 	 *  and stderr open for any pre-syslog error messages.
129 	 */
130 	{
131 		int i, nfds = getdtablesize();
132 
133 		for (i = 0; i < nfds; i++)
134 			if (i != STDIN_FILENO && i != STDOUT_FILENO &&
135 			    i != STDERR_FILENO)
136 				(void) close(i);
137 	}
138 
139 	/*
140 	 *  Parse any arguments.
141 	 */
142 	while ((c = getopt(argc, argv, "adi:")) != -1)
143 		switch(c) {
144 		    case 'a':
145 			BootAny++;
146 			break;
147 		    case 'd':
148 			DebugFlg++;
149 			break;
150 		    case 'i':
151 			IntfName = optarg;
152 			break;
153 		}
154 	for (; optind < argc; optind++) {
155 		if (ConfigFile == NULL)
156 			ConfigFile = argv[optind];
157 		else {
158 			warnx("too many config files (`%s' ignored)",
159 			    argv[optind]);
160 		}
161 	}
162 
163 	if (ConfigFile == NULL)			/* use default config file */
164 		ConfigFile = DfltConfig;
165 
166 	if (DebugFlg) {
167 		DbgFp = stdout;				/* output to stdout */
168 
169 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
170 		(void) signal(SIGUSR2, SIG_IGN);
171 		(void) fclose(stderr);			/* finished with it */
172 	} else {
173 		if (daemon(0, 0))
174 			err(1, "can't detach from terminal");
175 		pidfile(NULL);
176 
177 		(void) signal(SIGUSR1, DebugOn);
178 		(void) signal(SIGUSR2, DebugOff);
179 	}
180 
181 	openlog("rbootd", LOG_PID, LOG_DAEMON);
182 
183 	/*
184 	 *  If no interface was specified, get one now.
185 	 *
186 	 *  This is convoluted because we want to get the default interface
187 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
188 	 *  runs into an error, it will return a syslog-able error message
189 	 *  (in `errmsg') which will be displayed here.
190 	 */
191 	if (IntfName == NULL) {
192 		char *errmsg;
193 
194 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
195 			/* backslash to avoid trigraph ??) */
196 			syslog(LOG_NOTICE, "restarted (?\?)");
197 			syslog(LOG_ERR, errmsg);
198 			Exit(0);
199 		}
200 	}
201 
202 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
203 
204 	(void) signal(SIGHUP, ReConfig);
205 	(void) signal(SIGINT, Exit);
206 	(void) signal(SIGTERM, Exit);
207 
208 	/*
209 	 *  Grab our host name and pid.
210 	 */
211 	if (gethostname(MyHost, sizeof MyHost) < 0) {
212 		syslog(LOG_ERR, "gethostname: %m");
213 		Exit(0);
214 	}
215 	MyHost[sizeof(MyHost) - 1] = '\0';
216 
217 	/*
218 	 *  All boot files are relative to the boot directory, we might
219 	 *  as well chdir() there to make life easier.
220 	 */
221 	if (chdir(BootDir) < 0) {
222 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
223 		Exit(0);
224 	}
225 
226 	/*
227 	 *  Initial configuration.
228 	 */
229 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
230 	if (GetBootFiles() == 0)		/* get list of boot files */
231 		Exit(0);
232 	if (ParseConfig() == 0)			/* parse config file */
233 		Exit(0);
234 
235 	/*
236 	 *  Open and initialize a BPF device for the appropriate interface.
237 	 *  If an error is encountered, a message is displayed and Exit()
238 	 *  is called.
239 	 */
240 	fd = BpfOpen();
241 
242 	(void) sigsetmask(omask);		/* allow reconfig's */
243 
244 	/*
245 	 *  Main loop: receive a packet, determine where it came from,
246 	 *  and if we service this host, call routine to handle request.
247 	 */
248 	set[0].fd = fd;
249 	set[0].events = POLLIN;
250 	for (;;) {
251 		int nsel;
252 
253 		nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
254 
255 		if (nsel < 0) {
256 			if (errno == EINTR)
257 				continue;
258 			syslog(LOG_ERR, "poll: %m");
259 			Exit(0);
260 		} else if (nsel == 0) {		/* timeout */
261 			DoTimeout();			/* clear stale conns */
262 			continue;
263 		}
264 
265 		if (set[0].revents & POLLIN) {
266 			RMPCONN rconn;
267 			CLIENT *client;
268 			int doread = 1;
269 
270 			while (BpfRead(&rconn, doread)) {
271 				doread = 0;
272 
273 				if (DbgFp != NULL)	/* display packet */
274 					DispPkt(&rconn,DIR_RCVD);
275 
276 				omask = sigblock(sigmask(SIGHUP));
277 
278 				/*
279 				 *  If we do not restrict service, set the
280 				 *  client to NULL (ProcessPacket() handles
281 				 *  this).  Otherwise, check that we can
282 				 *  service this host; if not, log a message
283 				 *  and ignore the packet.
284 				 */
285 				if (BootAny) {
286 					client = NULL;
287 				} else if ((client=FindClient(&rconn))==NULL) {
288 					syslog(LOG_INFO,
289 					       "%s: boot packet ignored",
290 					       EnetStr(&rconn));
291 					(void) sigsetmask(omask);
292 					continue;
293 				}
294 
295 				ProcessPacket(&rconn,client);
296 
297 				(void) sigsetmask(omask);
298 			}
299 		}
300 	}
301 }
302 
303 /*
304 **  DoTimeout -- Free any connections that have timed out.
305 **
306 **	Parameters:
307 **		None.
308 **
309 **	Returns:
310 **		Nothing.
311 **
312 **	Side Effects:
313 **		- Timed out connections in `RmpConns' will be freed.
314 */
315 void
316 DoTimeout(void)
317 {
318 	RMPCONN *rtmp;
319 	struct timeval now;
320 
321 	(void) gettimeofday(&now, (struct timezone *)0);
322 
323 	/*
324 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
325 	 *  since the last packet was sent, delete the connection.
326 	 */
327 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
328 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
329 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
330 			       EnetStr(rtmp), rtmp->rmp.r_type);
331 			RemoveConn(rtmp);
332 		}
333 }
334 
335 /*
336 **  FindClient -- Find client associated with a packet.
337 **
338 **	Parameters:
339 **		rconn - the new packet.
340 **
341 **	Returns:
342 **		Pointer to client info if found, NULL otherwise.
343 **
344 **	Side Effects:
345 **		None.
346 **
347 **	Warnings:
348 **		- This routine must be called with SIGHUP blocked since
349 **		  a reconfigure can invalidate the information returned.
350 */
351 
352 CLIENT *
353 FindClient(RMPCONN *rconn)
354 {
355 	CLIENT *ctmp;
356 
357 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
358 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
359 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
360 			break;
361 
362 	return(ctmp);
363 }
364 
365 /*
366 **  Exit -- Log an error message and exit.
367 **
368 **	Parameters:
369 **		sig - caught signal (or zero if not dying on a signal).
370 **
371 **	Returns:
372 **		Does not return.
373 **
374 **	Side Effects:
375 **		- This process ceases to exist.
376 */
377 void
378 Exit(int sig)
379 {
380 	if (sig > 0)
381 		syslog(LOG_ERR, "going down on signal %d", sig);
382 	else
383 		syslog(LOG_ERR, "going down with fatal error");
384 	BpfClose();
385 	exit(1);
386 }
387 
388 /*
389 **  ReConfig -- Get new list of boot files and reread config files.
390 **
391 **	Parameters:
392 **		None.
393 **
394 **	Returns:
395 **		Nothing.
396 **
397 **	Side Effects:
398 **		- All active connections are dropped.
399 **		- List of boot-able files is changed.
400 **		- List of clients is changed.
401 **
402 **	Warnings:
403 **		- This routine must be called with SIGHUP blocked.
404 */
405 void
406 ReConfig(int signo)
407 {
408 	syslog(LOG_NOTICE, "reconfiguring boot server");
409 
410 	FreeConns();
411 
412 	if (GetBootFiles() == 0)
413 		Exit(0);
414 
415 	if (ParseConfig() == 0)
416 		Exit(0);
417 }
418 
419 /*
420 **  DebugOff -- Turn off debugging.
421 **
422 **	Parameters:
423 **		None.
424 **
425 **	Returns:
426 **		Nothing.
427 **
428 **	Side Effects:
429 **		- Debug file is closed.
430 */
431 void
432 DebugOff(int signo)
433 {
434 	if (DbgFp != NULL)
435 		(void) fclose(DbgFp);
436 
437 	DbgFp = NULL;
438 }
439 
440 /*
441 **  DebugOn -- Turn on debugging.
442 **
443 **	Parameters:
444 **		None.
445 **
446 **	Returns:
447 **		Nothing.
448 **
449 **	Side Effects:
450 **		- Debug file is opened/truncated if not already opened,
451 **		  otherwise do nothing.
452 */
453 void
454 DebugOn(int signo)
455 {
456 	if (DbgFp == NULL) {
457 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
458 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
459 	}
460 }
461