xref: /freebsd/libexec/rbootd/rbootd.c (revision ea906c4152774dff300bb26fbfc1e4188351c89a)
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 			/* Backslash to avoid trigraph '??)'. */
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 - 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(void)
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(void)
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(RMPCONN *rconn)
348 {
349 	CLIENT *ctmp;
350 
351 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
352 		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
353 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
354 			break;
355 
356 	return(ctmp);
357 }
358 
359 /*
360 **  Exit -- Log an error message and exit.
361 **
362 **	Parameters:
363 **		sig - caught signal (or zero if not dying on a signal).
364 **
365 **	Returns:
366 **		Does not return.
367 **
368 **	Side Effects:
369 **		- This process ceases to exist.
370 */
371 void
372 Exit(int sig)
373 {
374 	if (sig > 0)
375 		syslog(LOG_ERR, "going down on signal %d", sig);
376 	else
377 		syslog(LOG_ERR, "going down with fatal error");
378 	BpfClose();
379 	exit(1);
380 }
381 
382 /*
383 **  ReConfig -- Get new list of boot files and reread config files.
384 **
385 **	Parameters:
386 **		None.
387 **
388 **	Returns:
389 **		Nothing.
390 **
391 **	Side Effects:
392 **		- All active connections are dropped.
393 **		- List of boot-able files is changed.
394 **		- List of clients is changed.
395 **
396 **	Warnings:
397 **		- This routine must be called with SIGHUP blocked.
398 */
399 void
400 ReConfig(int signo)
401 {
402 	syslog(LOG_NOTICE, "reconfiguring boot server");
403 
404 	FreeConns();
405 
406 	if (GetBootFiles() == 0)
407 		Exit(0);
408 
409 	if (ParseConfig() == 0)
410 		Exit(0);
411 }
412 
413 /*
414 **  DebugOff -- Turn off debugging.
415 **
416 **	Parameters:
417 **		None.
418 **
419 **	Returns:
420 **		Nothing.
421 **
422 **	Side Effects:
423 **		- Debug file is closed.
424 */
425 void
426 DebugOff(int signo)
427 {
428 	if (DbgFp != NULL)
429 		(void) fclose(DbgFp);
430 
431 	DbgFp = NULL;
432 }
433 
434 /*
435 **  DebugOn -- Turn on debugging.
436 **
437 **	Parameters:
438 **		None.
439 **
440 **	Returns:
441 **		Nothing.
442 **
443 **	Side Effects:
444 **		- Debug file is opened/truncated if not already opened,
445 **		  otherwise do nothing.
446 */
447 void
448 DebugOn(int signo)
449 {
450 	if (DbgFp == NULL) {
451 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
452 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
453 	}
454 }
455