xref: /netbsd/usr.sbin/rbootd/rbootd.c (revision c4a72b64)
1 /*	$NetBSD: rbootd.c,v 1.18 2002/09/23 12:48:07 mycroft 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 1.18 2002/09/23 12:48:07 mycroft Exp $");
61 #endif
62 #endif /* not lint */
63 
64 #include <sys/param.h>
65 #include <sys/time.h>
66 #include <poll.h>
67 #include <ctype.h>
68 #include <err.h>
69 #include <errno.h>
70 #include <fcntl.h>
71 #include <signal.h>
72 #include <stdio.h>
73 #include <stdlib.h>
74 #include <string.h>
75 #include <syslog.h>
76 #include <unistd.h>
77 #include <util.h>
78 #include "defs.h"
79 
80 int	main __P((int, char *[]));
81 
82 int
83 main(argc, argv)
84 	int argc;
85 	char *argv[];
86 {
87 	int c, fd, omask;
88 	struct pollfd set[1];
89 
90 	/*
91 	 *  Close any open file descriptors.
92 	 *  Temporarily leave stdin & stdout open for `-d',
93 	 *  and stderr open for any pre-syslog error messages.
94 	 */
95 	{
96 		int i, nfds = getdtablesize();
97 
98 		for (i = 0; i < nfds; i++)
99 			if (i != STDIN_FILENO && i != STDOUT_FILENO &&
100 			    i != STDERR_FILENO)
101 				(void) close(i);
102 	}
103 
104 	/*
105 	 *  Parse any arguments.
106 	 */
107 	while ((c = getopt(argc, argv, "adi:")) != -1)
108 		switch(c) {
109 		    case 'a':
110 			BootAny++;
111 			break;
112 		    case 'd':
113 			DebugFlg++;
114 			break;
115 		    case 'i':
116 			IntfName = optarg;
117 			break;
118 		}
119 	for (; optind < argc; optind++) {
120 		if (ConfigFile == NULL)
121 			ConfigFile = argv[optind];
122 		else {
123 			warnx("too many config files (`%s' ignored)",
124 			    argv[optind]);
125 		}
126 	}
127 
128 	if (ConfigFile == NULL)			/* use default config file */
129 		ConfigFile = DfltConfig;
130 
131 	if (DebugFlg) {
132 		DbgFp = stdout;				/* output to stdout */
133 
134 		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
135 		(void) signal(SIGUSR2, SIG_IGN);
136 		(void) fclose(stderr);			/* finished with it */
137 	} else {
138 		if (daemon(0, 0))
139 			err(1, "can't detach from terminal");
140 		pidfile(NULL);
141 
142 		(void) signal(SIGUSR1, DebugOn);
143 		(void) signal(SIGUSR2, DebugOff);
144 	}
145 
146 	openlog("rbootd", LOG_PID, LOG_DAEMON);
147 
148 	/*
149 	 *  If no interface was specified, get one now.
150 	 *
151 	 *  This is convoluted because we want to get the default interface
152 	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
153 	 *  runs into an error, it will return a syslog-able error message
154 	 *  (in `errmsg') which will be displayed here.
155 	 */
156 	if (IntfName == NULL) {
157 		char *errmsg;
158 
159 		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
160 			/* backslash to avoid trigraph ??) */
161 			syslog(LOG_NOTICE, "restarted (?\?)");
162 			syslog(LOG_ERR, errmsg);
163 			Exit(0);
164 		}
165 	}
166 
167 	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
168 
169 	(void) signal(SIGHUP, ReConfig);
170 	(void) signal(SIGINT, Exit);
171 	(void) signal(SIGTERM, Exit);
172 
173 	/*
174 	 *  Grab our host name and pid.
175 	 */
176 	if (gethostname(MyHost, sizeof MyHost) < 0) {
177 		syslog(LOG_ERR, "gethostname: %m");
178 		Exit(0);
179 	}
180 	MyHost[sizeof(MyHost) - 1] = '\0';
181 
182 	/*
183 	 *  All boot files are relative to the boot directory, we might
184 	 *  as well chdir() there to make life easier.
185 	 */
186 	if (chdir(BootDir) < 0) {
187 		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
188 		Exit(0);
189 	}
190 
191 	/*
192 	 *  Initial configuration.
193 	 */
194 	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
195 	if (GetBootFiles() == 0)		/* get list of boot files */
196 		Exit(0);
197 	if (ParseConfig() == 0)			/* parse config file */
198 		Exit(0);
199 
200 	/*
201 	 *  Open and initialize a BPF device for the appropriate interface.
202 	 *  If an error is encountered, a message is displayed and Exit()
203 	 *  is called.
204 	 */
205 	fd = BpfOpen();
206 
207 	(void) sigsetmask(omask);		/* allow reconfig's */
208 
209 	/*
210 	 *  Main loop: receive a packet, determine where it came from,
211 	 *  and if we service this host, call routine to handle request.
212 	 */
213 	set[0].fd = fd;
214 	set[0].events = POLLIN;
215 	for (;;) {
216 		int nsel;
217 
218 		nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
219 
220 		if (nsel < 0) {
221 			if (errno == EINTR)
222 				continue;
223 			syslog(LOG_ERR, "poll: %m");
224 			Exit(0);
225 		} else if (nsel == 0) {		/* timeout */
226 			DoTimeout();			/* clear stale conns */
227 			continue;
228 		}
229 
230 		if (set[0].revents & POLLIN) {
231 			RMPCONN rconn;
232 			CLIENT *client;
233 			int doread = 1;
234 
235 			while (BpfRead(&rconn, doread)) {
236 				doread = 0;
237 
238 				if (DbgFp != NULL)	/* display packet */
239 					DispPkt(&rconn,DIR_RCVD);
240 
241 				omask = sigblock(sigmask(SIGHUP));
242 
243 				/*
244 				 *  If we do not restrict service, set the
245 				 *  client to NULL (ProcessPacket() handles
246 				 *  this).  Otherwise, check that we can
247 				 *  service this host; if not, log a message
248 				 *  and ignore the packet.
249 				 */
250 				if (BootAny) {
251 					client = NULL;
252 				} else if ((client=FindClient(&rconn))==NULL) {
253 					syslog(LOG_INFO,
254 					       "%s: boot packet ignored",
255 					       EnetStr(&rconn));
256 					(void) sigsetmask(omask);
257 					continue;
258 				}
259 
260 				ProcessPacket(&rconn,client);
261 
262 				(void) sigsetmask(omask);
263 			}
264 		}
265 	}
266 }
267 
268 /*
269 **  DoTimeout -- Free any connections that have timed out.
270 **
271 **	Parameters:
272 **		None.
273 **
274 **	Returns:
275 **		Nothing.
276 **
277 **	Side Effects:
278 **		- Timed out connections in `RmpConns' will be freed.
279 */
280 void
281 DoTimeout()
282 {
283 	RMPCONN *rtmp;
284 	struct timeval now;
285 
286 	(void) gettimeofday(&now, (struct timezone *)0);
287 
288 	/*
289 	 *  For each active connection, if RMP_TIMEOUT seconds have passed
290 	 *  since the last packet was sent, delete the connection.
291 	 */
292 	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
293 		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
294 			syslog(LOG_WARNING, "%s: connection timed out (%u)",
295 			       EnetStr(rtmp), rtmp->rmp.r_type);
296 			RemoveConn(rtmp);
297 		}
298 }
299 
300 /*
301 **  FindClient -- Find client associated with a packet.
302 **
303 **	Parameters:
304 **		rconn - the new packet.
305 **
306 **	Returns:
307 **		Pointer to client info if found, NULL otherwise.
308 **
309 **	Side Effects:
310 **		None.
311 **
312 **	Warnings:
313 **		- This routine must be called with SIGHUP blocked since
314 **		  a reconfigure can invalidate the information returned.
315 */
316 
317 CLIENT *
318 FindClient(rconn)
319 	RMPCONN *rconn;
320 {
321 	CLIENT *ctmp;
322 
323 	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
324 		if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
325 		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
326 			break;
327 
328 	return(ctmp);
329 }
330 
331 /*
332 **  Exit -- Log an error message and exit.
333 **
334 **	Parameters:
335 **		sig - caught signal (or zero if not dying on a signal).
336 **
337 **	Returns:
338 **		Does not return.
339 **
340 **	Side Effects:
341 **		- This process ceases to exist.
342 */
343 void
344 Exit(sig)
345 	int sig;
346 {
347 	if (sig > 0)
348 		syslog(LOG_ERR, "going down on signal %d", sig);
349 	else
350 		syslog(LOG_ERR, "going down with fatal error");
351 	BpfClose();
352 	exit(1);
353 }
354 
355 /*
356 **  ReConfig -- Get new list of boot files and reread config files.
357 **
358 **	Parameters:
359 **		None.
360 **
361 **	Returns:
362 **		Nothing.
363 **
364 **	Side Effects:
365 **		- All active connections are dropped.
366 **		- List of boot-able files is changed.
367 **		- List of clients is changed.
368 **
369 **	Warnings:
370 **		- This routine must be called with SIGHUP blocked.
371 */
372 void
373 ReConfig(signo)
374 	int signo;
375 {
376 	syslog(LOG_NOTICE, "reconfiguring boot server");
377 
378 	FreeConns();
379 
380 	if (GetBootFiles() == 0)
381 		Exit(0);
382 
383 	if (ParseConfig() == 0)
384 		Exit(0);
385 }
386 
387 /*
388 **  DebugOff -- Turn off debugging.
389 **
390 **	Parameters:
391 **		None.
392 **
393 **	Returns:
394 **		Nothing.
395 **
396 **	Side Effects:
397 **		- Debug file is closed.
398 */
399 void
400 DebugOff(signo)
401 	int signo;
402 {
403 	if (DbgFp != NULL)
404 		(void) fclose(DbgFp);
405 
406 	DbgFp = NULL;
407 }
408 
409 /*
410 **  DebugOn -- Turn on debugging.
411 **
412 **	Parameters:
413 **		None.
414 **
415 **	Returns:
416 **		Nothing.
417 **
418 **	Side Effects:
419 **		- Debug file is opened/truncated if not already opened,
420 **		  otherwise do nothing.
421 */
422 void
423 DebugOn(signo)
424 	int signo;
425 {
426 	if (DbgFp == NULL) {
427 		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
428 			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
429 	}
430 }
431