xref: /netbsd/usr.sbin/rbootd/rbootd.c (revision 6550d01e)
1 /*	$NetBSD: rbootd.c,v 1.21 2008/07/21 13:36:59 lukem 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("@(#) Copyright (c) 1992, 1993\
90  The Regents of the University of California.  All rights reserved.");
91 #endif /* not lint */
92 
93 #ifndef lint
94 #if 0
95 static char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
96 #else
97 __RCSID("$NetBSD: rbootd.c,v 1.21 2008/07/21 13:36:59 lukem Exp $");
98 #endif
99 #endif /* not lint */
100 
101 #include <sys/param.h>
102 #include <sys/time.h>
103 #include <poll.h>
104 #include <err.h>
105 #include <errno.h>
106 #include <fcntl.h>
107 #include <signal.h>
108 #include <stdio.h>
109 #include <stdlib.h>
110 #include <string.h>
111 #include <syslog.h>
112 #include <unistd.h>
113 #include <util.h>
114 #include "defs.h"
115 
116 int	main (int, char *[]);
117 
118 int
119 main(int argc, char *argv[])
120 {
121 	int c, fd, omask;
122 	struct pollfd set[1];
123 
124 	/*
125 	 *  Close any open file descriptors.
126 	 *  Temporarily leave stdin & stdout open for `-d',
127 	 *  and stderr open for any pre-syslog error messages.
128 	 */
129 	{
130 		int i, nfds = getdtablesize();
131 
132 		for (i = 0; i < nfds; i++)
133 			if (i != STDIN_FILENO && i != STDOUT_FILENO &&
134 			    i != STDERR_FILENO)
135 				(void) close(i);
136 	}
137 
138 	/*
139 	 *  Parse any arguments.
140 	 */
141 	while ((c = getopt(argc, argv, "adi:")) != -1)
142 		switch(c) {
143 		    case 'a':
144 			BootAny++;
145 			break;
146 		    case 'd':
147 			DebugFlg++;
148 			break;
149 		    case 'i':
150 			IntfName = optarg;
151 			break;
152 		}
153 	for (; optind < argc; optind++) {
154 		if (ConfigFile == NULL)
155 			ConfigFile = argv[optind];
156 		else {
157 			warnx("too many config files (`%s' ignored)",
158 			    argv[optind]);
159 		}
160 	}
161 
162 	if (ConfigFile == NULL)			/* use default config file */
163 		ConfigFile = DfltConfig;
164 
165 	if (DebugFlg) {
166 		DbgFp = stdout;				/* output to stdout */
167 
168 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
169 		(void) signal(SIGUSR2, SIG_IGN);
170 		(void) fclose(stderr);			/* finished with it */
171 	} else {
172 		if (daemon(0, 0))
173 			err(1, "can't detach from terminal");
174 		pidfile(NULL);
175 
176 		(void) signal(SIGUSR1, DebugOn);
177 		(void) signal(SIGUSR2, DebugOff);
178 	}
179 
180 	openlog("rbootd", LOG_PID, LOG_DAEMON);
181 
182 	/*
183 	 *  If no interface was specified, get one now.
184 	 *
185 	 *  This is convoluted because we want to get the default interface
186 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
187 	 *  runs into an error, it will return a syslog-able error message
188 	 *  (in `errmsg') which will be displayed here.
189 	 */
190 	if (IntfName == NULL) {
191 		char *errmsg;
192 
193 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
194 			/* backslash to avoid trigraph ??) */
195 			syslog(LOG_NOTICE, "restarted (?\?)");
196 			syslog(LOG_ERR, errmsg);
197 			Exit(0);
198 		}
199 	}
200 
201 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
202 
203 	(void) signal(SIGHUP, ReConfig);
204 	(void) signal(SIGINT, Exit);
205 	(void) signal(SIGTERM, Exit);
206 
207 	/*
208 	 *  Grab our host name and pid.
209 	 */
210 	if (gethostname(MyHost, sizeof MyHost) < 0) {
211 		syslog(LOG_ERR, "gethostname: %m");
212 		Exit(0);
213 	}
214 	MyHost[sizeof(MyHost) - 1] = '\0';
215 
216 	/*
217 	 *  All boot files are relative to the boot directory, we might
218 	 *  as well chdir() there to make life easier.
219 	 */
220 	if (chdir(BootDir) < 0) {
221 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
222 		Exit(0);
223 	}
224 
225 	/*
226 	 *  Initial configuration.
227 	 */
228 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
229 	if (GetBootFiles() == 0)		/* get list of boot files */
230 		Exit(0);
231 	if (ParseConfig() == 0)			/* parse config file */
232 		Exit(0);
233 
234 	/*
235 	 *  Open and initialize a BPF device for the appropriate interface.
236 	 *  If an error is encountered, a message is displayed and Exit()
237 	 *  is called.
238 	 */
239 	fd = BpfOpen();
240 
241 	(void) sigsetmask(omask);		/* allow reconfig's */
242 
243 	/*
244 	 *  Main loop: receive a packet, determine where it came from,
245 	 *  and if we service this host, call routine to handle request.
246 	 */
247 	set[0].fd = fd;
248 	set[0].events = POLLIN;
249 	for (;;) {
250 		int nsel;
251 
252 		nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
253 
254 		if (nsel < 0) {
255 			if (errno == EINTR)
256 				continue;
257 			syslog(LOG_ERR, "poll: %m");
258 			Exit(0);
259 		} else if (nsel == 0) {		/* timeout */
260 			DoTimeout();			/* clear stale conns */
261 			continue;
262 		}
263 
264 		if (set[0].revents & POLLIN) {
265 			RMPCONN rconn;
266 			CLIENT *client;
267 			int doread = 1;
268 
269 			while (BpfRead(&rconn, doread)) {
270 				doread = 0;
271 
272 				if (DbgFp != NULL)	/* display packet */
273 					DispPkt(&rconn,DIR_RCVD);
274 
275 				omask = sigblock(sigmask(SIGHUP));
276 
277 				/*
278 				 *  If we do not restrict service, set the
279 				 *  client to NULL (ProcessPacket() handles
280 				 *  this).  Otherwise, check that we can
281 				 *  service this host; if not, log a message
282 				 *  and ignore the packet.
283 				 */
284 				if (BootAny) {
285 					client = NULL;
286 				} else if ((client=FindClient(&rconn))==NULL) {
287 					syslog(LOG_INFO,
288 					       "%s: boot packet ignored",
289 					       EnetStr(&rconn));
290 					(void) sigsetmask(omask);
291 					continue;
292 				}
293 
294 				ProcessPacket(&rconn,client);
295 
296 				(void) sigsetmask(omask);
297 			}
298 		}
299 	}
300 }
301 
302 /*
303 **  DoTimeout -- Free any connections that have timed out.
304 **
305 **	Parameters:
306 **		None.
307 **
308 **	Returns:
309 **		Nothing.
310 **
311 **	Side Effects:
312 **		- Timed out connections in `RmpConns' will be freed.
313 */
314 void
315 DoTimeout(void)
316 {
317 	RMPCONN *rtmp;
318 	struct timeval now;
319 
320 	(void) gettimeofday(&now, (struct timezone *)0);
321 
322 	/*
323 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
324 	 *  since the last packet was sent, delete the connection.
325 	 */
326 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
327 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
328 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
329 			       EnetStr(rtmp), rtmp->rmp.r_type);
330 			RemoveConn(rtmp);
331 		}
332 }
333 
334 /*
335 **  FindClient -- Find client associated with a packet.
336 **
337 **	Parameters:
338 **		rconn - the new packet.
339 **
340 **	Returns:
341 **		Pointer to client info if found, NULL otherwise.
342 **
343 **	Side Effects:
344 **		None.
345 **
346 **	Warnings:
347 **		- This routine must be called with SIGHUP blocked since
348 **		  a reconfigure can invalidate the information returned.
349 */
350 
351 CLIENT *
352 FindClient(RMPCONN *rconn)
353 {
354 	CLIENT *ctmp;
355 
356 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
357 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
358 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
359 			break;
360 
361 	return(ctmp);
362 }
363 
364 /*
365 **  Exit -- Log an error message and exit.
366 **
367 **	Parameters:
368 **		sig - caught signal (or zero if not dying on a signal).
369 **
370 **	Returns:
371 **		Does not return.
372 **
373 **	Side Effects:
374 **		- This process ceases to exist.
375 */
376 void
377 Exit(int sig)
378 {
379 	if (sig > 0)
380 		syslog(LOG_ERR, "going down on signal %d", sig);
381 	else
382 		syslog(LOG_ERR, "going down with fatal error");
383 	BpfClose();
384 	exit(1);
385 }
386 
387 /*
388 **  ReConfig -- Get new list of boot files and reread config files.
389 **
390 **	Parameters:
391 **		None.
392 **
393 **	Returns:
394 **		Nothing.
395 **
396 **	Side Effects:
397 **		- All active connections are dropped.
398 **		- List of boot-able files is changed.
399 **		- List of clients is changed.
400 **
401 **	Warnings:
402 **		- This routine must be called with SIGHUP blocked.
403 */
404 void
405 ReConfig(int signo)
406 {
407 	syslog(LOG_NOTICE, "reconfiguring boot server");
408 
409 	FreeConns();
410 
411 	if (GetBootFiles() == 0)
412 		Exit(0);
413 
414 	if (ParseConfig() == 0)
415 		Exit(0);
416 }
417 
418 /*
419 **  DebugOff -- Turn off debugging.
420 **
421 **	Parameters:
422 **		None.
423 **
424 **	Returns:
425 **		Nothing.
426 **
427 **	Side Effects:
428 **		- Debug file is closed.
429 */
430 void
431 DebugOff(int signo)
432 {
433 	if (DbgFp != NULL)
434 		(void) fclose(DbgFp);
435 
436 	DbgFp = NULL;
437 }
438 
439 /*
440 **  DebugOn -- Turn on debugging.
441 **
442 **	Parameters:
443 **		None.
444 **
445 **	Returns:
446 **		Nothing.
447 **
448 **	Side Effects:
449 **		- Debug file is opened/truncated if not already opened,
450 **		  otherwise do nothing.
451 */
452 void
453 DebugOn(int signo)
454 {
455 	if (DbgFp == NULL) {
456 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
457 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
458 	}
459 }
460