xref: /freebsd/libexec/rbootd/rbootd.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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(void);
76 
77 int
78 main(int argc, char *argv[])
79 {
80 	int c, fd, omask, maxfds;
81 	fd_set rset;
82 
83 	/*
84 	 *  Close any open file descriptors.
85 	 *  Temporarily leave stdin & stdout open for `-d',
86 	 *  and stderr open for any pre-syslog error messages.
87 	 */
88 	{
89 		int i, nfds = getdtablesize();
90 
91 		for (i = 0; i < nfds; i++)
92 			if (i != fileno(stdin) && i != fileno(stdout) &&
93 			    i != fileno(stderr))
94 				(void) close(i);
95 	}
96 
97 	/*
98 	 *  Parse any arguments.
99 	 */
100 	while ((c = getopt(argc, argv, "adi:")) != -1)
101 		switch(c) {
102 		    case 'a':
103 			BootAny++;
104 			break;
105 		    case 'd':
106 			DebugFlg++;
107 			break;
108 		    case 'i':
109 			IntfName = optarg;
110 			break;
111 		    default:
112 			usage();
113 		}
114 	for (; optind < argc; optind++) {
115 		if (ConfigFile == NULL)
116 			ConfigFile = argv[optind];
117 		else {
118 			warnx("too many config files (`%s' ignored)",
119 			    argv[optind]);
120 		}
121 	}
122 
123 	if (ConfigFile == NULL)			/* use default config file */
124 		ConfigFile = DfltConfig;
125 
126 	if (DebugFlg) {
127 		DbgFp = stdout;				/* output to stdout */
128 
129 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
130 		(void) signal(SIGUSR2, SIG_IGN);
131 		(void) fclose(stderr);			/* finished with it */
132 	} else {
133 		if (daemon(0, 0))
134 			err(1, "can't detach from terminal");
135 
136 		(void) signal(SIGUSR1, DebugOn);
137 		(void) signal(SIGUSR2, DebugOff);
138 	}
139 
140 	openlog("rbootd", LOG_PID, LOG_DAEMON);
141 
142 	/*
143 	 *  If no interface was specified, get one now.
144 	 *
145 	 *  This is convoluted because we want to get the default interface
146 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
147 	 *  runs into an error, it will return a syslog-able error message
148 	 *  (in `errmsg') which will be displayed here.
149 	 */
150 	if (IntfName == NULL) {
151 		char *errmsg;
152 
153 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
154 			syslog(LOG_NOTICE, "restarted (??)");
155 			/* BpfGetIntfName() returns safe names, using %m */
156 			syslog(LOG_ERR, "%s", errmsg);
157 			Exit(0);
158 		}
159 	}
160 
161 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
162 
163 	(void) signal(SIGHUP, ReConfig);
164 	(void) signal(SIGINT, Exit);
165 	(void) signal(SIGTERM, Exit);
166 
167 	/*
168 	 *  Grab our host name and pid.
169 	 */
170 	if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) {
171 		syslog(LOG_ERR, "gethostname: %m");
172 		Exit(0);
173 	}
174 	MyHost[MAXHOSTNAMELEN - 1] = '\0';
175 
176 	MyPid = getpid();
177 
178 	/*
179 	 *  Write proc's pid to a file.
180 	 */
181 	{
182 		FILE *fp;
183 
184 		if ((fp = fopen(PidFile, "w")) != NULL) {
185 			(void) fprintf(fp, "%d\n", (int) MyPid);
186 			(void) fclose(fp);
187 		} else {
188 			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
189 		}
190 	}
191 
192 	/*
193 	 *  All boot files are relative to the boot directory, we might
194 	 *  as well chdir() there to make life easier.
195 	 */
196 	if (chdir(BootDir) < 0) {
197 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
198 		Exit(0);
199 	}
200 
201 	/*
202 	 *  Initial configuration.
203 	 */
204 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
205 	if (GetBootFiles() == 0)		/* get list of boot files */
206 		Exit(0);
207 	if (ParseConfig() == 0)			/* parse config file */
208 		Exit(0);
209 
210 	/*
211 	 *  Open and initialize a BPF device for the appropriate interface.
212 	 *  If an error is encountered, a message is displayed and Exit()
213 	 *  is called.
214 	 */
215 	fd = BpfOpen();
216 
217 	(void) sigsetmask(omask);		/* allow reconfig's */
218 
219 	/*
220 	 *  Main loop: receive a packet, determine where it came from,
221 	 *  and if we service this host, call routine to handle request.
222 	 */
223 	maxfds = fd + 1;
224 	FD_ZERO(&rset);
225 	FD_SET(fd, &rset);
226 	for (;;) {
227 		struct timeval timeout;
228 		fd_set r;
229 		int nsel;
230 
231 		r = rset;
232 
233 		if (RmpConns == NULL) {		/* timeout isnt necessary */
234 			nsel = select(maxfds, &r, NULL, NULL, NULL);
235 		} else {
236 			timeout.tv_sec = RMP_TIMEOUT;
237 			timeout.tv_usec = 0;
238 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
239 		}
240 
241 		if (nsel < 0) {
242 			if (errno == EINTR)
243 				continue;
244 			syslog(LOG_ERR, "select: %m");
245 			Exit(0);
246 		} else if (nsel == 0) {		/* timeout */
247 			DoTimeout();			/* clear stale conns */
248 			continue;
249 		}
250 
251 		if (FD_ISSET(fd, &r)) {
252 			RMPCONN rconn;
253 			CLIENT *client, *FindClient();
254 			int doread = 1;
255 
256 			while (BpfRead(&rconn, doread)) {
257 				doread = 0;
258 
259 				if (DbgFp != NULL)	/* display packet */
260 					DispPkt(&rconn,DIR_RCVD);
261 
262 				omask = sigblock(sigmask(SIGHUP));
263 
264 				/*
265 				 *  If we do not restrict service, set the
266 				 *  client to NULL (ProcessPacket() handles
267 				 *  this).  Otherwise, check that we can
268 				 *  service this host; if not, log a message
269 				 *  and ignore the packet.
270 				 */
271 				if (BootAny) {
272 					client = NULL;
273 				} else if ((client=FindClient(&rconn))==NULL) {
274 					syslog(LOG_INFO,
275 					       "%s: boot packet ignored",
276 					       EnetStr(&rconn));
277 					(void) sigsetmask(omask);
278 					continue;
279 				}
280 
281 				ProcessPacket(&rconn,client);
282 
283 				(void) sigsetmask(omask);
284 			}
285 		}
286 	}
287 }
288 
289 static void
290 usage(void)
291 {
292 	fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
293 	exit (1);
294 }
295 
296 /*
297 **  DoTimeout -- Free any connections that have timed out.
298 **
299 **	Parameters:
300 **		None.
301 **
302 **	Returns:
303 **		Nothing.
304 **
305 **	Side Effects:
306 **		- Timed out connections in `RmpConns' will be freed.
307 */
308 void
309 DoTimeout(void)
310 {
311 	RMPCONN *rtmp;
312 	struct timeval now;
313 
314 	(void) gettimeofday(&now, (struct timezone *)0);
315 
316 	/*
317 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
318 	 *  since the last packet was sent, delete the connection.
319 	 */
320 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
321 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
322 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
323 			       EnetStr(rtmp), rtmp->rmp.r_type);
324 			RemoveConn(rtmp);
325 		}
326 }
327 
328 /*
329 **  FindClient -- Find client associated with a packet.
330 **
331 **	Parameters:
332 **		rconn - the new packet.
333 **
334 **	Returns:
335 **		Pointer to client info if found, NULL otherwise.
336 **
337 **	Side Effects:
338 **		None.
339 **
340 **	Warnings:
341 **		- This routine must be called with SIGHUP blocked since
342 **		  a reconfigure can invalidate the information returned.
343 */
344 
345 CLIENT *
346 FindClient(RMPCONN *rconn)
347 {
348 	CLIENT *ctmp;
349 
350 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
351 		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
352 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
353 			break;
354 
355 	return(ctmp);
356 }
357 
358 /*
359 **  Exit -- Log an error message and exit.
360 **
361 **	Parameters:
362 **		sig - caught signal (or zero if not dying on a signal).
363 **
364 **	Returns:
365 **		Does not return.
366 **
367 **	Side Effects:
368 **		- This process ceases to exist.
369 */
370 void
371 Exit(int sig)
372 {
373 	if (sig > 0)
374 		syslog(LOG_ERR, "going down on signal %d", sig);
375 	else
376 		syslog(LOG_ERR, "going down with fatal error");
377 	BpfClose();
378 	exit(1);
379 }
380 
381 /*
382 **  ReConfig -- Get new list of boot files and reread config files.
383 **
384 **	Parameters:
385 **		None.
386 **
387 **	Returns:
388 **		Nothing.
389 **
390 **	Side Effects:
391 **		- All active connections are dropped.
392 **		- List of boot-able files is changed.
393 **		- List of clients is changed.
394 **
395 **	Warnings:
396 **		- This routine must be called with SIGHUP blocked.
397 */
398 void
399 ReConfig(int signo)
400 {
401 	syslog(LOG_NOTICE, "reconfiguring boot server");
402 
403 	FreeConns();
404 
405 	if (GetBootFiles() == 0)
406 		Exit(0);
407 
408 	if (ParseConfig() == 0)
409 		Exit(0);
410 }
411 
412 /*
413 **  DebugOff -- Turn off debugging.
414 **
415 **	Parameters:
416 **		None.
417 **
418 **	Returns:
419 **		Nothing.
420 **
421 **	Side Effects:
422 **		- Debug file is closed.
423 */
424 void
425 DebugOff(int signo)
426 {
427 	if (DbgFp != NULL)
428 		(void) fclose(DbgFp);
429 
430 	DbgFp = NULL;
431 }
432 
433 /*
434 **  DebugOn -- Turn on debugging.
435 **
436 **	Parameters:
437 **		None.
438 **
439 **	Returns:
440 **		Nothing.
441 **
442 **	Side Effects:
443 **		- Debug file is opened/truncated if not already opened,
444 **		  otherwise do nothing.
445 */
446 void
447 DebugOn(int signo)
448 {
449 	if (DbgFp == NULL) {
450 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
451 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
452 	}
453 }
454