xref: /netbsd-src/usr.sbin/rbootd/rbootd.c (revision bcc8ec9959e7b01e313d813067bfb43a3ad70551)
1 /*	$NetBSD: rbootd.c,v 1.13 2001/01/16 02:36:29 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1992 The University of Utah and the Center
5  *	for Software Science (CSS).
6  * Copyright (c) 1992, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * the Center for Software Science of the University of Utah Computer
11  * Science Department.  CSS requests users of this software to return
12  * to css-dist@cs.utah.edu any improvements that they make and grant
13  * CSS redistribution rights.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. All advertising materials mentioning features or use of this software
24  *    must display the following acknowledgement:
25  *	This product includes software developed by the University of
26  *	California, Berkeley and its contributors.
27  * 4. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
44  *
45  * From: Utah Hdr: rbootd.c 3.1 92/07/06
46  * Author: Jeff Forys, University of Utah CSS
47  */
48 
49 #include <sys/cdefs.h>
50 #ifndef lint
51 __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 #if 0
58 static char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
59 #else
60 __RCSID("$NetBSD: rbootd.c,v 1.13 2001/01/16 02:36:29 cgd Exp $");
61 #endif
62 #endif /* not lint */
63 
64 #include <sys/param.h>
65 #include <sys/time.h>
66 #include <ctype.h>
67 #include <err.h>
68 #include <errno.h>
69 #include <fcntl.h>
70 #include <signal.h>
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <string.h>
74 #include <syslog.h>
75 #include <unistd.h>
76 #include <util.h>
77 #include "defs.h"
78 
79 int	main __P((int, char *[]));
80 
81 extern	char *__progname;	/* from crt0.o */
82 
83 int
84 main(argc, argv)
85 	int argc;
86 	char *argv[];
87 {
88 	int c, fd, omask, maxfds;
89 	fd_set rset;
90 
91 	/*
92 	 *  Close any open file descriptors.
93 	 *  Temporarily leave stdin & stdout open for `-d',
94 	 *  and stderr open for any pre-syslog error messages.
95 	 */
96 	{
97 		int i, nfds = getdtablesize();
98 
99 		for (i = 0; i < nfds; i++)
100 			if (i != fileno(stdin) && i != fileno(stdout) &&
101 			    i != fileno(stderr))
102 				(void) close(i);
103 	}
104 
105 	/*
106 	 *  Parse any arguments.
107 	 */
108 	while ((c = getopt(argc, argv, "adi:")) != -1)
109 		switch(c) {
110 		    case 'a':
111 			BootAny++;
112 			break;
113 		    case 'd':
114 			DebugFlg++;
115 			break;
116 		    case 'i':
117 			IntfName = optarg;
118 			break;
119 		}
120 	for (; optind < argc; optind++) {
121 		if (ConfigFile == NULL)
122 			ConfigFile = argv[optind];
123 		else {
124 			warnx("too many config files (`%s' ignored)\n",
125 			    argv[optind]);
126 		}
127 	}
128 
129 	if (ConfigFile == NULL)			/* use default config file */
130 		ConfigFile = DfltConfig;
131 
132 	if (DebugFlg) {
133 		DbgFp = stdout;				/* output to stdout */
134 
135 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
136 		(void) signal(SIGUSR2, SIG_IGN);
137 		(void) fclose(stderr);			/* finished with it */
138 	} else {
139 		if (daemon(0, 0))
140 			err(1, "can't detach from terminal");
141 		pidfile(NULL);
142 
143 		(void) signal(SIGUSR1, DebugOn);
144 		(void) signal(SIGUSR2, DebugOff);
145 	}
146 
147 	openlog("rbootd", LOG_PID, LOG_DAEMON);
148 
149 	/*
150 	 *  If no interface was specified, get one now.
151 	 *
152 	 *  This is convoluted because we want to get the default interface
153 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
154 	 *  runs into an error, it will return a syslog-able error message
155 	 *  (in `errmsg') which will be displayed here.
156 	 */
157 	if (IntfName == NULL) {
158 		char *errmsg;
159 
160 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
161 			/* backslash to avoid trigraph ??) */
162 			syslog(LOG_NOTICE, "restarted (?\?)");
163 			syslog(LOG_ERR, errmsg);
164 			Exit(0);
165 		}
166 	}
167 
168 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
169 
170 	(void) signal(SIGHUP, ReConfig);
171 	(void) signal(SIGINT, Exit);
172 	(void) signal(SIGTERM, Exit);
173 
174 	/*
175 	 *  Grab our host name and pid.
176 	 */
177 	if (gethostname(MyHost, sizeof MyHost) < 0) {
178 		syslog(LOG_ERR, "gethostname: %m");
179 		Exit(0);
180 	}
181 	MyHost[sizeof(MyHost) - 1] = '\0';
182 
183 	/*
184 	 *  All boot files are relative to the boot directory, we might
185 	 *  as well chdir() there to make life easier.
186 	 */
187 	if (chdir(BootDir) < 0) {
188 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
189 		Exit(0);
190 	}
191 
192 	/*
193 	 *  Initial configuration.
194 	 */
195 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
196 	if (GetBootFiles() == 0)		/* get list of boot files */
197 		Exit(0);
198 	if (ParseConfig() == 0)			/* parse config file */
199 		Exit(0);
200 
201 	/*
202 	 *  Open and initialize a BPF device for the appropriate interface.
203 	 *  If an error is encountered, a message is displayed and Exit()
204 	 *  is called.
205 	 */
206 	fd = BpfOpen();
207 
208 	(void) sigsetmask(omask);		/* allow reconfig's */
209 
210 	/*
211 	 *  Main loop: receive a packet, determine where it came from,
212 	 *  and if we service this host, call routine to handle request.
213 	 */
214 	maxfds = fd + 1;
215 	FD_ZERO(&rset);
216 	FD_SET(fd, &rset);
217 	for (;;) {
218 		struct timeval timeout;
219 		fd_set r;
220 		int nsel;
221 
222 		r = rset;
223 
224 		if (RmpConns == NULL) {		/* timeout isnt necessary */
225 			nsel = select(maxfds, &r, NULL, NULL, NULL);
226 		} else {
227 			timeout.tv_sec = RMP_TIMEOUT;
228 			timeout.tv_usec = 0;
229 			nsel = select(maxfds, &r, NULL, NULL, &timeout);
230 		}
231 
232 		if (nsel < 0) {
233 			if (errno == EINTR)
234 				continue;
235 			syslog(LOG_ERR, "select: %m");
236 			Exit(0);
237 		} else if (nsel == 0) {		/* timeout */
238 			DoTimeout();			/* clear stale conns */
239 			continue;
240 		}
241 
242 		if (FD_ISSET(fd, &r)) {
243 			RMPCONN rconn;
244 			CLIENT *client;
245 			int doread = 1;
246 
247 			while (BpfRead(&rconn, doread)) {
248 				doread = 0;
249 
250 				if (DbgFp != NULL)	/* display packet */
251 					DispPkt(&rconn,DIR_RCVD);
252 
253 				omask = sigblock(sigmask(SIGHUP));
254 
255 				/*
256 				 *  If we do not restrict service, set the
257 				 *  client to NULL (ProcessPacket() handles
258 				 *  this).  Otherwise, check that we can
259 				 *  service this host; if not, log a message
260 				 *  and ignore the packet.
261 				 */
262 				if (BootAny) {
263 					client = NULL;
264 				} else if ((client=FindClient(&rconn))==NULL) {
265 					syslog(LOG_INFO,
266 					       "%s: boot packet ignored",
267 					       EnetStr(&rconn));
268 					(void) sigsetmask(omask);
269 					continue;
270 				}
271 
272 				ProcessPacket(&rconn,client);
273 
274 				(void) sigsetmask(omask);
275 			}
276 		}
277 	}
278 }
279 
280 /*
281 **  DoTimeout -- Free any connections that have timed out.
282 **
283 **	Parameters:
284 **		None.
285 **
286 **	Returns:
287 **		Nothing.
288 **
289 **	Side Effects:
290 **		- Timed out connections in `RmpConns' will be freed.
291 */
292 void
293 DoTimeout()
294 {
295 	RMPCONN *rtmp;
296 	struct timeval now;
297 
298 	(void) gettimeofday(&now, (struct timezone *)0);
299 
300 	/*
301 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
302 	 *  since the last packet was sent, delete the connection.
303 	 */
304 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
305 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
306 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
307 			       EnetStr(rtmp), rtmp->rmp.r_type);
308 			RemoveConn(rtmp);
309 		}
310 }
311 
312 /*
313 **  FindClient -- Find client associated with a packet.
314 **
315 **	Parameters:
316 **		rconn - the new packet.
317 **
318 **	Returns:
319 **		Pointer to client info if found, NULL otherwise.
320 **
321 **	Side Effects:
322 **		None.
323 **
324 **	Warnings:
325 **		- This routine must be called with SIGHUP blocked since
326 **		  a reconfigure can invalidate the information returned.
327 */
328 
329 CLIENT *
330 FindClient(rconn)
331 	RMPCONN *rconn;
332 {
333 	CLIENT *ctmp;
334 
335 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
336 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
337 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
338 			break;
339 
340 	return(ctmp);
341 }
342 
343 /*
344 **  Exit -- Log an error message and exit.
345 **
346 **	Parameters:
347 **		sig - caught signal (or zero if not dying on a signal).
348 **
349 **	Returns:
350 **		Does not return.
351 **
352 **	Side Effects:
353 **		- This process ceases to exist.
354 */
355 void
356 Exit(sig)
357 	int sig;
358 {
359 	if (sig > 0)
360 		syslog(LOG_ERR, "going down on signal %d", sig);
361 	else
362 		syslog(LOG_ERR, "going down with fatal error");
363 	BpfClose();
364 	exit(1);
365 }
366 
367 /*
368 **  ReConfig -- Get new list of boot files and reread config files.
369 **
370 **	Parameters:
371 **		None.
372 **
373 **	Returns:
374 **		Nothing.
375 **
376 **	Side Effects:
377 **		- All active connections are dropped.
378 **		- List of boot-able files is changed.
379 **		- List of clients is changed.
380 **
381 **	Warnings:
382 **		- This routine must be called with SIGHUP blocked.
383 */
384 void
385 ReConfig(signo)
386 	int signo;
387 {
388 	syslog(LOG_NOTICE, "reconfiguring boot server");
389 
390 	FreeConns();
391 
392 	if (GetBootFiles() == 0)
393 		Exit(0);
394 
395 	if (ParseConfig() == 0)
396 		Exit(0);
397 }
398 
399 /*
400 **  DebugOff -- Turn off debugging.
401 **
402 **	Parameters:
403 **		None.
404 **
405 **	Returns:
406 **		Nothing.
407 **
408 **	Side Effects:
409 **		- Debug file is closed.
410 */
411 void
412 DebugOff(signo)
413 	int signo;
414 {
415 	if (DbgFp != NULL)
416 		(void) fclose(DbgFp);
417 
418 	DbgFp = NULL;
419 }
420 
421 /*
422 **  DebugOn -- Turn on debugging.
423 **
424 **	Parameters:
425 **		None.
426 **
427 **	Returns:
428 **		Nothing.
429 **
430 **	Side Effects:
431 **		- Debug file is opened/truncated if not already opened,
432 **		  otherwise do nothing.
433 */
434 void
435 DebugOn(signo)
436 	int signo;
437 {
438 	if (DbgFp == NULL) {
439 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
440 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
441 	}
442 }
443