xref: /openbsd-src/usr.sbin/rbootd/rbootd.c (revision 3a3fbb3f2e2521ab7c4a56b7ff7462ebd9095ec5)
1 /*	$OpenBSD: rbootd.c,v 1.9 2001/12/01 23:27:23 miod Exp $	*/
2 /*	$NetBSD: rbootd.c,v 1.5 1995/10/06 05:12:17 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1992 The University of Utah and the Center
6  *	for Software Science (CSS).
7  * Copyright (c) 1992, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * the Center for Software Science of the University of Utah Computer
12  * Science Department.  CSS requests users of this software to return
13  * to css-dist@cs.utah.edu any improvements that they make and grant
14  * CSS redistribution rights.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  * 3. All advertising materials mentioning features or use of this software
25  *    must display the following acknowledgement:
26  *	This product includes software developed by the University of
27  *	California, Berkeley and its contributors.
28  * 4. Neither the name of the University nor the names of its contributors
29  *    may be used to endorse or promote products derived from this software
30  *    without specific prior written permission.
31  *
32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42  * SUCH DAMAGE.
43  *
44  *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
45  *
46  * From: Utah Hdr: rbootd.c 3.1 92/07/06
47  * Author: Jeff Forys, University of Utah CSS
48  */
49 
50 #ifndef lint
51 static char 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 /*static char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";*/
58 static char rcsid[] = "$OpenBSD: rbootd.c,v 1.9 2001/12/01 23:27:23 miod Exp $";
59 #endif /* not lint */
60 
61 #include <sys/param.h>
62 #include <sys/time.h>
63 #include <ctype.h>
64 #include <err.h>
65 #include <errno.h>
66 #include <fcntl.h>
67 #include <signal.h>
68 #include <stdio.h>
69 #include <stdlib.h>
70 #include <string.h>
71 #include <syslog.h>
72 #include <unistd.h>
73 #include "defs.h"
74 
75 extern	char *__progname;	/* from crt0.o */
76 
77 int
78 main(argc, argv)
79 	int argc;
80 	char *argv[];
81 {
82 	int c, fd, maxfds;
83 	fd_set rset;
84 	sigset_t hmask, omask;
85 
86 	/*
87 	 *  Close any open file descriptors.
88 	 *  Temporarily leave stdin & stdout open for `-d',
89 	 *  and stderr open for any pre-syslog error messages.
90 	 */
91 	{
92 		int i, nfds = getdtablesize();
93 
94 		for (i = 0; i < nfds; i++)
95 			if (i != fileno(stdin) && i != fileno(stdout) &&
96 			    i != fileno(stderr))
97 				(void) close(i);
98 	}
99 
100 	/*
101 	 *  Parse any arguments.
102 	 */
103 	while ((c = getopt(argc, argv, "adi:")) != -1)
104 		switch(c) {
105 		    case 'a':
106 			BootAny++;
107 			break;
108 		    case 'd':
109 			DebugFlg++;
110 			break;
111 		    case 'i':
112 			IntfName = optarg;
113 			break;
114 		}
115 	for (; optind < argc; optind++) {
116 		if (ConfigFile == NULL)
117 			ConfigFile = argv[optind];
118 		else {
119 			warnx("too many config files (`%s' ignored)",
120 			    argv[optind]);
121 		}
122 	}
123 
124 	if (ConfigFile == NULL)			/* use default config file */
125 		ConfigFile = DfltConfig;
126 
127 	if (DebugFlg) {
128 		DbgFp = stdout;				/* output to stdout */
129 
130 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
131 		(void) signal(SIGUSR2, SIG_IGN);
132 		(void) fclose(stderr);			/* finished with it */
133 	} else {
134 		if (daemon(0, 0))
135 			err(1, "can't detach from terminal");
136 
137 		(void) signal(SIGUSR1, DebugOn);
138 		(void) signal(SIGUSR2, DebugOff);
139 	}
140 
141 	openlog(__progname, LOG_PID, LOG_DAEMON);
142 
143 	/*
144 	 *  If no interface was specified, get one now.
145 	 *
146 	 *  This is convoluted because we want to get the default interface
147 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
148 	 *  runs into an error, it will return a syslog-able error message
149 	 *  (in `errmsg') which will be displayed here.
150 	 */
151 	if (IntfName == NULL) {
152 		char *errmsg;
153 
154 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
155 			syslog(LOG_NOTICE, "restarted (??)");
156 			/* BpfGetIntfName() returns safe names, using %m */
157 			syslog(LOG_ERR, "%s", errmsg);
158 			Exit(0);
159 		}
160 	}
161 
162 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
163 
164 	(void) signal(SIGHUP, ReConfig);
165 	(void) signal(SIGINT, Exit);
166 	(void) signal(SIGTERM, Exit);
167 
168 	/*
169 	 *  Grab our host name and pid.
170 	 */
171 	if (gethostname(MyHost, MAXHOSTNAMELEN) < 0) {
172 		syslog(LOG_ERR, "gethostname: %m");
173 		Exit(0);
174 	}
175 	MyHost[MAXHOSTNAMELEN] = '\0';
176 
177 	/*
178 	 *  Write proc's pid to a file.
179 	 */
180 	if (pidfile(NULL) < 0) {
181 		syslog(LOG_WARNING, "pidfile: failed");
182 	}
183 
184 	/*
185 	 *  All boot files are relative to the boot directory, we might
186 	 *  as well chdir() there to make life easier.
187 	 */
188 	if (chdir(BootDir) < 0) {
189 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
190 		Exit(0);
191 	}
192 
193 	/*
194 	 *  Initial configuration.
195 	 */
196 	sigemptyset(&hmask);
197 	sigaddset(&hmask, SIGHUP);
198 	sigprocmask(SIG_BLOCK, &hmask, &omask);	/* prevent reconfig's */
199 	if (GetBootFiles() == 0)		/* get list of boot files */
200 		Exit(0);
201 	if (ParseConfig() == 0)			/* parse config file */
202 		Exit(0);
203 
204 	/*
205 	 *  Open and initialize a BPF device for the appropriate interface.
206 	 *  If an error is encountered, a message is displayed and Exit()
207 	 *  is called.
208 	 */
209 	fd = BpfOpen();
210 
211 	sigprocmask(SIG_SETMASK, &omask, NULL);	/* allow reconfig's */
212 
213 	/*
214 	 *  Main loop: receive a packet, determine where it came from,
215 	 *  and if we service this host, call routine to handle request.
216 	 */
217 	maxfds = fd + 1;
218 	FD_ZERO(&rset);
219 	FD_SET(fd, &rset);
220 	for (;;) {
221 		struct timeval timeout;
222 		fd_set r;
223 		int nsel;
224 
225 		r = rset;
226 
227 		if (RmpConns == NULL) {		/* timeout isnt necessary */
228 			nsel = select(maxfds, &r, NULL, NULL, NULL);
229 		} else {
230 			timeout.tv_sec = RMP_TIMEOUT;
231 			timeout.tv_usec = 0;
232 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
233 		}
234 
235 		if (nsel < 0) {
236 			if (errno == EINTR)
237 				continue;
238 			syslog(LOG_ERR, "select: %m");
239 			Exit(0);
240 		} else if (nsel == 0) {		/* timeout */
241 			DoTimeout();			/* clear stale conns */
242 			continue;
243 		}
244 
245 		if (FD_ISSET(fd, &r)) {
246 			RMPCONN rconn;
247 			CLIENT *client, *FindClient();
248 			int doread = 1;
249 
250 			while (BpfRead(&rconn, doread)) {
251 				doread = 0;
252 
253 				if (DbgFp != NULL)	/* display packet */
254 					DispPkt(&rconn,DIR_RCVD);
255 
256 				sigprocmask(SIG_BLOCK, &hmask, &omask);
257 
258 				/*
259 				 *  If we do not restrict service, set the
260 				 *  client to NULL (ProcessPacket() handles
261 				 *  this).  Otherwise, check that we can
262 				 *  service this host; if not, log a message
263 				 *  and ignore the packet.
264 				 */
265 				if (BootAny) {
266 					client = NULL;
267 				} else if ((client=FindClient(&rconn))==NULL) {
268 					syslog(LOG_INFO,
269 					       "%s: boot packet ignored",
270 					       EnetStr(&rconn));
271 					sigprocmask(SIG_SETMASK, &omask, NULL);
272 					continue;
273 				}
274 
275 				ProcessPacket(&rconn,client);
276 
277 				sigprocmask(SIG_SETMASK, &omask, NULL);
278 			}
279 		}
280 	}
281 }
282 
283 /*
284 **  DoTimeout -- Free any connections that have timed out.
285 **
286 **	Parameters:
287 **		None.
288 **
289 **	Returns:
290 **		Nothing.
291 **
292 **	Side Effects:
293 **		- Timed out connections in `RmpConns' will be freed.
294 */
295 void
296 DoTimeout()
297 {
298 	register RMPCONN *rtmp;
299 	struct timeval now;
300 
301 	(void) gettimeofday(&now, (struct timezone *)0);
302 
303 	/*
304 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
305 	 *  since the last packet was sent, delete the connection.
306 	 */
307 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
308 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
309 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
310 			       EnetStr(rtmp), rtmp->rmp.r_type);
311 			RemoveConn(rtmp);
312 		}
313 }
314 
315 /*
316 **  FindClient -- Find client associated with a packet.
317 **
318 **	Parameters:
319 **		rconn - the new packet.
320 **
321 **	Returns:
322 **		Pointer to client info if found, NULL otherwise.
323 **
324 **	Side Effects:
325 **		None.
326 **
327 **	Warnings:
328 **		- This routine must be called with SIGHUP blocked since
329 **		  a reconfigure can invalidate the information returned.
330 */
331 
332 CLIENT *
333 FindClient(rconn)
334 	register RMPCONN *rconn;
335 {
336 	register CLIENT *ctmp;
337 
338 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
339 		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
340 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
341 			break;
342 
343 	return(ctmp);
344 }
345 
346 /*
347 **  Exit -- Log an error message and exit.
348 **
349 **	Parameters:
350 **		sig - caught signal (or zero if not dying on a signal).
351 **
352 **	Returns:
353 **		Does not return.
354 **
355 **	Side Effects:
356 **		- This process ceases to exist.
357 */
358 void
359 Exit(sig)
360 	int sig;
361 {
362 	/* XXX race */
363 	if (sig > 0)
364 		syslog(LOG_ERR, "going down on signal %d", sig);
365 	else
366 		syslog(LOG_ERR, "going down with fatal error");
367 	BpfClose();
368 	exit(1);
369 }
370 
371 /*
372 **  ReConfig -- Get new list of boot files and reread config files.
373 **
374 **	Parameters:
375 **		None.
376 **
377 **	Returns:
378 **		Nothing.
379 **
380 **	Side Effects:
381 **		- All active connections are dropped.
382 **		- List of boot-able files is changed.
383 **		- List of clients is changed.
384 **
385 **	Warnings:
386 **		- This routine must be called with SIGHUP blocked.
387 */
388 void
389 ReConfig(signo)
390 	int signo;
391 {
392 	/* XXX race */
393 	syslog(LOG_NOTICE, "reconfiguring boot server");
394 
395 	FreeConns();
396 
397 	if (GetBootFiles() == 0)
398 		Exit(0);
399 
400 	if (ParseConfig() == 0)
401 		Exit(0);
402 }
403 
404 /*
405 **  DebugOff -- Turn off debugging.
406 **
407 **	Parameters:
408 **		None.
409 **
410 **	Returns:
411 **		Nothing.
412 **
413 **	Side Effects:
414 **		- Debug file is closed.
415 */
416 void
417 DebugOff(signo)
418 	int signo;
419 {
420 	/* XXX race */
421 
422 	if (DbgFp != NULL)
423 		(void) fclose(DbgFp);
424 
425 	DbgFp = NULL;
426 }
427 
428 /*
429 **  DebugOn -- Turn on debugging.
430 **
431 **	Parameters:
432 **		None.
433 **
434 **	Returns:
435 **		Nothing.
436 **
437 **	Side Effects:
438 **		- Debug file is opened/truncated if not already opened,
439 **		  otherwise do nothing.
440 */
441 void
442 DebugOn(signo)
443 	int signo;
444 {
445 	/* XXX race */
446 	if (DbgFp == NULL) {
447 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
448 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
449 	}
450 }
451