xref: /freebsd/libexec/rbootd/rbootd.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
1 /*
2  * Copyright (c) 1988, 1992 The University of Utah and the Center
3  *	for Software Science (CSS).
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. All advertising materials mentioning features or use of this software
22  *    must display the following acknowledgement:
23  *	This product includes software developed by the University of
24  *	California, Berkeley and its contributors.
25  * 4. Neither the name of the University nor the names of its contributors
26  *    may be used to endorse or promote products derived from this software
27  *    without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39  * SUCH DAMAGE.
40  *
41  *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
42  *
43  * From: Utah Hdr: rbootd.c 3.1 92/07/06
44  * Author: Jeff Forys, University of Utah CSS
45  */
46 
47 #ifndef lint
48 static const char copyright[] =
49 "@(#) Copyright (c) 1992, 1993\n\
50 	The Regents of the University of California.  All rights reserved.\n";
51 #endif /* not lint */
52 
53 #ifndef lint
54 #if 0
55 static const char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
56 #endif
57 static const char rcsid[] =
58   "$FreeBSD$";
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 static void usage __P((void));
76 
77 int
78 main(argc, argv)
79 	int argc;
80 	char *argv[];
81 {
82 	int c, fd, omask, maxfds;
83 	fd_set rset;
84 
85 	/*
86 	 *  Close any open file descriptors.
87 	 *  Temporarily leave stdin & stdout open for `-d',
88 	 *  and stderr open for any pre-syslog error messages.
89 	 */
90 	{
91 		int i, nfds = getdtablesize();
92 
93 		for (i = 0; i < nfds; i++)
94 			if (i != fileno(stdin) && i != fileno(stdout) &&
95 			    i != fileno(stderr))
96 				(void) close(i);
97 	}
98 
99 	/*
100 	 *  Parse any arguments.
101 	 */
102 	while ((c = getopt(argc, argv, "adi:")) != -1)
103 		switch(c) {
104 		    case 'a':
105 			BootAny++;
106 			break;
107 		    case 'd':
108 			DebugFlg++;
109 			break;
110 		    case 'i':
111 			IntfName = optarg;
112 			break;
113 		    default:
114 			usage();
115 		}
116 	for (; optind < argc; optind++) {
117 		if (ConfigFile == NULL)
118 			ConfigFile = argv[optind];
119 		else {
120 			warnx("too many config files (`%s' ignored)",
121 			    argv[optind]);
122 		}
123 	}
124 
125 	if (ConfigFile == NULL)			/* use default config file */
126 		ConfigFile = DfltConfig;
127 
128 	if (DebugFlg) {
129 		DbgFp = stdout;				/* output to stdout */
130 
131 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
132 		(void) signal(SIGUSR2, SIG_IGN);
133 		(void) fclose(stderr);			/* finished with it */
134 	} else {
135 		if (daemon(0, 0))
136 			err(1, "can't detach from terminal");
137 
138 		(void) signal(SIGUSR1, DebugOn);
139 		(void) signal(SIGUSR2, DebugOff);
140 	}
141 
142 	openlog("rbootd", LOG_PID, LOG_DAEMON);
143 
144 	/*
145 	 *  If no interface was specified, get one now.
146 	 *
147 	 *  This is convoluted because we want to get the default interface
148 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
149 	 *  runs into an error, it will return a syslog-able error message
150 	 *  (in `errmsg') which will be displayed here.
151 	 */
152 	if (IntfName == NULL) {
153 		char *errmsg;
154 
155 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
156 			syslog(LOG_NOTICE, "restarted (??)");
157 			/* BpfGetIntfName() returns safe names, using %m */
158 			syslog(LOG_ERR, "%s", errmsg);
159 			Exit(0);
160 		}
161 	}
162 
163 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
164 
165 	(void) signal(SIGHUP, ReConfig);
166 	(void) signal(SIGINT, Exit);
167 	(void) signal(SIGTERM, Exit);
168 
169 	/*
170 	 *  Grab our host name and pid.
171 	 */
172 	if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) {
173 		syslog(LOG_ERR, "gethostname: %m");
174 		Exit(0);
175 	}
176 	MyHost[MAXHOSTNAMELEN - 1] = '\0';
177 
178 	MyPid = getpid();
179 
180 	/*
181 	 *  Write proc's pid to a file.
182 	 */
183 	{
184 		FILE *fp;
185 
186 		if ((fp = fopen(PidFile, "w")) != NULL) {
187 			(void) fprintf(fp, "%d\n", (int) MyPid);
188 			(void) fclose(fp);
189 		} else {
190 			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
191 		}
192 	}
193 
194 	/*
195 	 *  All boot files are relative to the boot directory, we might
196 	 *  as well chdir() there to make life easier.
197 	 */
198 	if (chdir(BootDir) < 0) {
199 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
200 		Exit(0);
201 	}
202 
203 	/*
204 	 *  Initial configuration.
205 	 */
206 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
207 	if (GetBootFiles() == 0)		/* get list of boot files */
208 		Exit(0);
209 	if (ParseConfig() == 0)			/* parse config file */
210 		Exit(0);
211 
212 	/*
213 	 *  Open and initialize a BPF device for the appropriate interface.
214 	 *  If an error is encountered, a message is displayed and Exit()
215 	 *  is called.
216 	 */
217 	fd = BpfOpen();
218 
219 	(void) sigsetmask(omask);		/* allow reconfig's */
220 
221 	/*
222 	 *  Main loop: receive a packet, determine where it came from,
223 	 *  and if we service this host, call routine to handle request.
224 	 */
225 	maxfds = fd + 1;
226 	FD_ZERO(&rset);
227 	FD_SET(fd, &rset);
228 	for (;;) {
229 		struct timeval timeout;
230 		fd_set r;
231 		int nsel;
232 
233 		r = rset;
234 
235 		if (RmpConns == NULL) {		/* timeout isnt necessary */
236 			nsel = select(maxfds, &r, NULL, NULL, NULL);
237 		} else {
238 			timeout.tv_sec = RMP_TIMEOUT;
239 			timeout.tv_usec = 0;
240 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
241 		}
242 
243 		if (nsel < 0) {
244 			if (errno == EINTR)
245 				continue;
246 			syslog(LOG_ERR, "select: %m");
247 			Exit(0);
248 		} else if (nsel == 0) {		/* timeout */
249 			DoTimeout();			/* clear stale conns */
250 			continue;
251 		}
252 
253 		if (FD_ISSET(fd, &r)) {
254 			RMPCONN rconn;
255 			CLIENT *client, *FindClient();
256 			int doread = 1;
257 
258 			while (BpfRead(&rconn, doread)) {
259 				doread = 0;
260 
261 				if (DbgFp != NULL)	/* display packet */
262 					DispPkt(&rconn,DIR_RCVD);
263 
264 				omask = sigblock(sigmask(SIGHUP));
265 
266 				/*
267 				 *  If we do not restrict service, set the
268 				 *  client to NULL (ProcessPacket() handles
269 				 *  this).  Otherwise, check that we can
270 				 *  service this host; if not, log a message
271 				 *  and ignore the packet.
272 				 */
273 				if (BootAny) {
274 					client = NULL;
275 				} else if ((client=FindClient(&rconn))==NULL) {
276 					syslog(LOG_INFO,
277 					       "%s: boot packet ignored",
278 					       EnetStr(&rconn));
279 					(void) sigsetmask(omask);
280 					continue;
281 				}
282 
283 				ProcessPacket(&rconn,client);
284 
285 				(void) sigsetmask(omask);
286 			}
287 		}
288 	}
289 }
290 
291 static void
292 usage()
293 {
294 	fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
295 	exit (1);
296 }
297 
298 /*
299 **  DoTimeout -- Free any connections that have timed out.
300 **
301 **	Parameters:
302 **		None.
303 **
304 **	Returns:
305 **		Nothing.
306 **
307 **	Side Effects:
308 **		- Timed out connections in `RmpConns' will be freed.
309 */
310 void
311 DoTimeout()
312 {
313 	RMPCONN *rtmp;
314 	struct timeval now;
315 
316 	(void) gettimeofday(&now, (struct timezone *)0);
317 
318 	/*
319 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
320 	 *  since the last packet was sent, delete the connection.
321 	 */
322 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
323 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
324 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
325 			       EnetStr(rtmp), rtmp->rmp.r_type);
326 			RemoveConn(rtmp);
327 		}
328 }
329 
330 /*
331 **  FindClient -- Find client associated with a packet.
332 **
333 **	Parameters:
334 **		rconn - the new packet.
335 **
336 **	Returns:
337 **		Pointer to client info if found, NULL otherwise.
338 **
339 **	Side Effects:
340 **		None.
341 **
342 **	Warnings:
343 **		- This routine must be called with SIGHUP blocked since
344 **		  a reconfigure can invalidate the information returned.
345 */
346 
347 CLIENT *
348 FindClient(rconn)
349 	RMPCONN *rconn;
350 {
351 	CLIENT *ctmp;
352 
353 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
354 		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
355 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
356 			break;
357 
358 	return(ctmp);
359 }
360 
361 /*
362 **  Exit -- Log an error message and exit.
363 **
364 **	Parameters:
365 **		sig - caught signal (or zero if not dying on a signal).
366 **
367 **	Returns:
368 **		Does not return.
369 **
370 **	Side Effects:
371 **		- This process ceases to exist.
372 */
373 void
374 Exit(sig)
375 	int sig;
376 {
377 	if (sig > 0)
378 		syslog(LOG_ERR, "going down on signal %d", sig);
379 	else
380 		syslog(LOG_ERR, "going down with fatal error");
381 	BpfClose();
382 	exit(1);
383 }
384 
385 /*
386 **  ReConfig -- Get new list of boot files and reread config files.
387 **
388 **	Parameters:
389 **		None.
390 **
391 **	Returns:
392 **		Nothing.
393 **
394 **	Side Effects:
395 **		- All active connections are dropped.
396 **		- List of boot-able files is changed.
397 **		- List of clients is changed.
398 **
399 **	Warnings:
400 **		- This routine must be called with SIGHUP blocked.
401 */
402 void
403 ReConfig(signo)
404 	int signo;
405 {
406 	syslog(LOG_NOTICE, "reconfiguring boot server");
407 
408 	FreeConns();
409 
410 	if (GetBootFiles() == 0)
411 		Exit(0);
412 
413 	if (ParseConfig() == 0)
414 		Exit(0);
415 }
416 
417 /*
418 **  DebugOff -- Turn off debugging.
419 **
420 **	Parameters:
421 **		None.
422 **
423 **	Returns:
424 **		Nothing.
425 **
426 **	Side Effects:
427 **		- Debug file is closed.
428 */
429 void
430 DebugOff(signo)
431 	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(signo)
454 	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