xref: /freebsd/libexec/rbootd/rbootd.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
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 			syslog(LOG_ERR, 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 - 1) < 0) {
172 		syslog(LOG_ERR, "gethostname: %m");
173 		Exit(0);
174 	}
175 	MyHost[MAXHOSTNAMELEN - 1] = '\0';
176 
177 	MyPid = getpid();
178 
179 	/*
180 	 *  Write proc's pid to a file.
181 	 */
182 	{
183 		FILE *fp;
184 
185 		if ((fp = fopen(PidFile, "w")) != NULL) {
186 			(void) fprintf(fp, "%d\n", (int) MyPid);
187 			(void) fclose(fp);
188 		} else {
189 			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
190 		}
191 	}
192 
193 	/*
194 	 *  All boot files are relative to the boot directory, we might
195 	 *  as well chdir() there to make life easier.
196 	 */
197 	if (chdir(BootDir) < 0) {
198 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
199 		Exit(0);
200 	}
201 
202 	/*
203 	 *  Initial configuration.
204 	 */
205 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
206 	if (GetBootFiles() == 0)		/* get list of boot files */
207 		Exit(0);
208 	if (ParseConfig() == 0)			/* parse config file */
209 		Exit(0);
210 
211 	/*
212 	 *  Open and initialize a BPF device for the appropriate interface.
213 	 *  If an error is encountered, a message is displayed and Exit()
214 	 *  is called.
215 	 */
216 	fd = BpfOpen();
217 
218 	(void) sigsetmask(omask);		/* allow reconfig's */
219 
220 	/*
221 	 *  Main loop: receive a packet, determine where it came from,
222 	 *  and if we service this host, call routine to handle request.
223 	 */
224 	maxfds = fd + 1;
225 	FD_ZERO(&rset);
226 	FD_SET(fd, &rset);
227 	for (;;) {
228 		struct timeval timeout;
229 		fd_set r;
230 		int nsel;
231 
232 		r = rset;
233 
234 		if (RmpConns == NULL) {		/* timeout isnt necessary */
235 			nsel = select(maxfds, &r, NULL, NULL, NULL);
236 		} else {
237 			timeout.tv_sec = RMP_TIMEOUT;
238 			timeout.tv_usec = 0;
239 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
240 		}
241 
242 		if (nsel < 0) {
243 			if (errno == EINTR)
244 				continue;
245 			syslog(LOG_ERR, "select: %m");
246 			Exit(0);
247 		} else if (nsel == 0) {		/* timeout */
248 			DoTimeout();			/* clear stale conns */
249 			continue;
250 		}
251 
252 		if (FD_ISSET(fd, &r)) {
253 			RMPCONN rconn;
254 			CLIENT *client, *FindClient();
255 			int doread = 1;
256 
257 			while (BpfRead(&rconn, doread)) {
258 				doread = 0;
259 
260 				if (DbgFp != NULL)	/* display packet */
261 					DispPkt(&rconn,DIR_RCVD);
262 
263 				omask = sigblock(sigmask(SIGHUP));
264 
265 				/*
266 				 *  If we do not restrict service, set the
267 				 *  client to NULL (ProcessPacket() handles
268 				 *  this).  Otherwise, check that we can
269 				 *  service this host; if not, log a message
270 				 *  and ignore the packet.
271 				 */
272 				if (BootAny) {
273 					client = NULL;
274 				} else if ((client=FindClient(&rconn))==NULL) {
275 					syslog(LOG_INFO,
276 					       "%s: boot packet ignored",
277 					       EnetStr(&rconn));
278 					(void) sigsetmask(omask);
279 					continue;
280 				}
281 
282 				ProcessPacket(&rconn,client);
283 
284 				(void) sigsetmask(omask);
285 			}
286 		}
287 	}
288 }
289 
290 static void
291 usage()
292 {
293 	fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
294 	exit (1);
295 }
296 
297 /*
298 **  DoTimeout -- Free any connections that have timed out.
299 **
300 **	Parameters:
301 **		None.
302 **
303 **	Returns:
304 **		Nothing.
305 **
306 **	Side Effects:
307 **		- Timed out connections in `RmpConns' will be freed.
308 */
309 void
310 DoTimeout()
311 {
312 	RMPCONN *rtmp;
313 	struct timeval now;
314 
315 	(void) gettimeofday(&now, (struct timezone *)0);
316 
317 	/*
318 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
319 	 *  since the last packet was sent, delete the connection.
320 	 */
321 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
322 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
323 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
324 			       EnetStr(rtmp), rtmp->rmp.r_type);
325 			RemoveConn(rtmp);
326 		}
327 }
328 
329 /*
330 **  FindClient -- Find client associated with a packet.
331 **
332 **	Parameters:
333 **		rconn - the new packet.
334 **
335 **	Returns:
336 **		Pointer to client info if found, NULL otherwise.
337 **
338 **	Side Effects:
339 **		None.
340 **
341 **	Warnings:
342 **		- This routine must be called with SIGHUP blocked since
343 **		  a reconfigure can invalidate the information returned.
344 */
345 
346 CLIENT *
347 FindClient(rconn)
348 	RMPCONN *rconn;
349 {
350 	CLIENT *ctmp;
351 
352 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
353 		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
354 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
355 			break;
356 
357 	return(ctmp);
358 }
359 
360 /*
361 **  Exit -- Log an error message and exit.
362 **
363 **	Parameters:
364 **		sig - caught signal (or zero if not dying on a signal).
365 **
366 **	Returns:
367 **		Does not return.
368 **
369 **	Side Effects:
370 **		- This process ceases to exist.
371 */
372 void
373 Exit(sig)
374 	int sig;
375 {
376 	if (sig > 0)
377 		syslog(LOG_ERR, "going down on signal %d", sig);
378 	else
379 		syslog(LOG_ERR, "going down with fatal error");
380 	BpfClose();
381 	exit(1);
382 }
383 
384 /*
385 **  ReConfig -- Get new list of boot files and reread config files.
386 **
387 **	Parameters:
388 **		None.
389 **
390 **	Returns:
391 **		Nothing.
392 **
393 **	Side Effects:
394 **		- All active connections are dropped.
395 **		- List of boot-able files is changed.
396 **		- List of clients is changed.
397 **
398 **	Warnings:
399 **		- This routine must be called with SIGHUP blocked.
400 */
401 void
402 ReConfig(signo)
403 	int signo;
404 {
405 	syslog(LOG_NOTICE, "reconfiguring boot server");
406 
407 	FreeConns();
408 
409 	if (GetBootFiles() == 0)
410 		Exit(0);
411 
412 	if (ParseConfig() == 0)
413 		Exit(0);
414 }
415 
416 /*
417 **  DebugOff -- Turn off debugging.
418 **
419 **	Parameters:
420 **		None.
421 **
422 **	Returns:
423 **		Nothing.
424 **
425 **	Side Effects:
426 **		- Debug file is closed.
427 */
428 void
429 DebugOff(signo)
430 	int signo;
431 {
432 	if (DbgFp != NULL)
433 		(void) fclose(DbgFp);
434 
435 	DbgFp = NULL;
436 }
437 
438 /*
439 **  DebugOn -- Turn on debugging.
440 **
441 **	Parameters:
442 **		None.
443 **
444 **	Returns:
445 **		Nothing.
446 **
447 **	Side Effects:
448 **		- Debug file is opened/truncated if not already opened,
449 **		  otherwise do nothing.
450 */
451 void
452 DebugOn(signo)
453 	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