rbootd.c revision 1593 
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 *	@(#)rbootd.c	8.2 (Berkeley) 2/22/94
42 *
43 * Utah $Hdr: rbootd.c 3.1 92/07/06$
44 * Author: Jeff Forys, University of Utah CSS
45 */
46
47#ifndef lint
48static 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
54static char sccsid[] = "@(#)rbootd.c	8.2 (Berkeley) 2/22/94";
55#endif /* not lint */
56
57#include <sys/param.h>
58#include <sys/ioctl.h>
59#include <sys/time.h>
60
61#include <ctype.h>
62#include <errno.h>
63#include <fcntl.h>
64#include <signal.h>
65#include <stdio.h>
66#include <stdlib.h>
67#include <string.h>
68#include <syslog.h>
69#include <unistd.h>
70#include "defs.h"
71
72
73/* fd mask macros (backward compatibility with 4.2BSD) */
74#ifndef	FD_SET
75#ifdef	notdef
76typedef	struct fd_set {		/* this should already be in 4.2 */
77	int fds_bits[1];
78} fd_set;
79#endif
80#define	FD_ZERO(p)	((p)->fds_bits[0] = 0)
81#define	FD_SET(n, p)	((p)->fds_bits[0] |= (1 << (n)))
82#define	FD_CLR(n, p)	((p)->fds_bits[0] &= ~(1 << (n)))
83#define	FD_ISSET(n, p)	((p)->fds_bits[0] & (1 << (n)))
84#endif
85
86int
87main(argc, argv)
88	int argc;
89	char *argv[];
90{
91	int c, fd, omask, maxfds;
92	fd_set rset;
93
94	/*
95	 *  Find what name we are running under.
96	 */
97	ProgName = (ProgName = rindex(argv[0],'/')) ? ++ProgName : *argv;
98
99	/*
100	 *  Close any open file descriptors.
101	 *  Temporarily leave stdin & stdout open for `-d',
102	 *  and stderr open for any pre-syslog error messages.
103	 */
104	{
105		int i, nfds = getdtablesize();
106
107		for (i = 0; i < nfds; i++)
108			if (i != fileno(stdin) && i != fileno(stdout) &&
109			    i != fileno(stderr))
110				(void) close(i);
111	}
112
113	/*
114	 *  Parse any arguments.
115	 */
116	while ((c = getopt(argc, argv, "adi:")) != EOF)
117		switch(c) {
118		    case 'a':
119			BootAny++;
120			break;
121		    case 'd':
122			DebugFlg++;
123			break;
124		    case 'i':
125			IntfName = optarg;
126			break;
127		}
128	for (; optind < argc; optind++) {
129		if (ConfigFile == NULL)
130			ConfigFile = argv[optind];
131		else {
132			fprintf(stderr,
133			        "%s: too many config files (`%s' ignored)\n",
134			        ProgName, argv[optind]);
135		}
136	}
137
138	if (ConfigFile == NULL)			/* use default config file */
139		ConfigFile = DfltConfig;
140
141	if (DebugFlg) {
142		DbgFp = stdout;				/* output to stdout */
143
144		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
145		(void) signal(SIGUSR2, SIG_IGN);
146	} else {
147		(void) fclose(stdin);			/* dont need these */
148		(void) fclose(stdout);
149
150		/*
151		 *  Fork off a child to do the work & exit.
152		 */
153		switch(fork()) {
154			case -1:	/* fork failed */
155				fprintf(stderr, "%s: ", ProgName);
156				perror("fork");
157				Exit(0);
158			case 0:		/* this is the CHILD */
159				break;
160			default:	/* this is the PARENT */
161				_exit(0);
162		}
163
164		/*
165		 *  Try to disassociate from the current tty.
166		 */
167		{
168			char *devtty = "/dev/tty";
169			int i;
170
171			if ((i = open(devtty, O_RDWR)) < 0) {
172				/* probably already disassociated */
173				if (setpgrp(0, 0) < 0) {
174					fprintf(stderr, "%s: ", ProgName);
175					perror("setpgrp");
176				}
177			} else {
178				if (ioctl(i, (u_long)TIOCNOTTY, (char *)0) < 0){
179					fprintf(stderr, "%s: ", ProgName);
180					perror("ioctl");
181				}
182				(void) close(i);
183			}
184		}
185
186		(void) signal(SIGUSR1, DebugOn);
187		(void) signal(SIGUSR2, DebugOff);
188	}
189
190	(void) fclose(stderr);		/* finished with it */
191
192#ifdef SYSLOG4_2
193	openlog(ProgName, LOG_PID);
194#else
195	openlog(ProgName, LOG_PID, LOG_DAEMON);
196#endif
197
198	/*
199	 *  If no interface was specified, get one now.
200	 *
201	 *  This is convoluted because we want to get the default interface
202	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
203	 *  runs into an error, it will return a syslog-able error message
204	 *  (in `errmsg') which will be displayed here.
205	 */
206	if (IntfName == NULL) {
207		char *errmsg;
208
209		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
210			syslog(LOG_NOTICE, "restarted (??)");
211			syslog(LOG_ERR, errmsg);
212			Exit(0);
213		}
214	}
215
216	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
217
218	(void) signal(SIGHUP, ReConfig);
219	(void) signal(SIGINT, Exit);
220	(void) signal(SIGTERM, Exit);
221
222	/*
223	 *  Grab our host name and pid.
224	 */
225	if (gethostname(MyHost, MAXHOSTNAMELEN) < 0) {
226		syslog(LOG_ERR, "gethostname: %m");
227		Exit(0);
228	}
229	MyHost[MAXHOSTNAMELEN] = '\0';
230
231	MyPid = getpid();
232
233	/*
234	 *  Write proc's pid to a file.
235	 */
236	{
237		FILE *fp;
238
239		if ((fp = fopen(PidFile, "w")) != NULL) {
240			(void) fprintf(fp, "%d\n", MyPid);
241			(void) fclose(fp);
242		} else {
243			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
244		}
245	}
246
247	/*
248	 *  All boot files are relative to the boot directory, we might
249	 *  as well chdir() there to make life easier.
250	 */
251	if (chdir(BootDir) < 0) {
252		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
253		Exit(0);
254	}
255
256	/*
257	 *  Initial configuration.
258	 */
259	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
260	if (GetBootFiles() == 0)		/* get list of boot files */
261		Exit(0);
262	if (ParseConfig() == 0)			/* parse config file */
263		Exit(0);
264
265	/*
266	 *  Open and initialize a BPF device for the appropriate interface.
267	 *  If an error is encountered, a message is displayed and Exit()
268	 *  is called.
269	 */
270	fd = BpfOpen();
271
272	(void) sigsetmask(omask);		/* allow reconfig's */
273
274	/*
275	 *  Main loop: receive a packet, determine where it came from,
276	 *  and if we service this host, call routine to handle request.
277	 */
278	maxfds = fd + 1;
279	FD_ZERO(&rset);
280	FD_SET(fd, &rset);
281	for (;;) {
282		struct timeval timeout;
283		fd_set r;
284		int nsel;
285
286		r = rset;
287
288		if (RmpConns == NULL) {		/* timeout isnt necessary */
289			nsel = select(maxfds, &r, (fd_set *)0, (fd_set *)0,
290			              (struct timeval *)0);
291		} else {
292			timeout.tv_sec = RMP_TIMEOUT;
293			timeout.tv_usec = 0;
294			nsel = select(maxfds, &r, (fd_set *)0, (fd_set *)0,
295			              &timeout);
296		}
297
298		if (nsel < 0) {
299			if (errno == EINTR)
300				continue;
301			syslog(LOG_ERR, "select: %m");
302			Exit(0);
303		} else if (nsel == 0) {		/* timeout */
304			DoTimeout();			/* clear stale conns */
305			continue;
306		}
307
308		if (FD_ISSET(fd, &r)) {
309			RMPCONN rconn;
310			CLIENT *client, *FindClient();
311			int doread = 1;
312
313			while (BpfRead(&rconn, doread)) {
314				doread = 0;
315
316				if (DbgFp != NULL)	/* display packet */
317					DispPkt(&rconn,DIR_RCVD);
318
319				omask = sigblock(sigmask(SIGHUP));
320
321				/*
322				 *  If we do not restrict service, set the
323				 *  client to NULL (ProcessPacket() handles
324				 *  this).  Otherwise, check that we can
325				 *  service this host; if not, log a message
326				 *  and ignore the packet.
327				 */
328				if (BootAny) {
329					client = NULL;
330				} else if ((client=FindClient(&rconn))==NULL) {
331					syslog(LOG_INFO,
332					       "%s: boot packet ignored",
333					       EnetStr(&rconn));
334					(void) sigsetmask(omask);
335					continue;
336				}
337
338				ProcessPacket(&rconn,client);
339
340				(void) sigsetmask(omask);
341			}
342		}
343	}
344}
345
346/*
347**  DoTimeout -- Free any connections that have timed out.
348**
349**	Parameters:
350**		None.
351**
352**	Returns:
353**		Nothing.
354**
355**	Side Effects:
356**		- Timed out connections in `RmpConns' will be freed.
357*/
358void
359DoTimeout()
360{
361	register RMPCONN *rtmp;
362	struct timeval now;
363
364	(void) gettimeofday(&now, (struct timezone *)0);
365
366	/*
367	 *  For each active connection, if RMP_TIMEOUT seconds have passed
368	 *  since the last packet was sent, delete the connection.
369	 */
370	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
371		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
372			syslog(LOG_WARNING, "%s: connection timed out (%u)",
373			       EnetStr(rtmp), rtmp->rmp.r_type);
374			RemoveConn(rtmp);
375		}
376}
377
378/*
379**  FindClient -- Find client associated with a packet.
380**
381**	Parameters:
382**		rconn - the new packet.
383**
384**	Returns:
385**		Pointer to client info if found, NULL otherwise.
386**
387**	Side Effects:
388**		None.
389**
390**	Warnings:
391**		- This routine must be called with SIGHUP blocked since
392**		  a reconfigure can invalidate the information returned.
393*/
394
395CLIENT *
396FindClient(rconn)
397	register RMPCONN *rconn;
398{
399	register CLIENT *ctmp;
400
401	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
402		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
403		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
404			break;
405
406	return(ctmp);
407}
408
409/*
410**  Exit -- Log an error message and exit.
411**
412**	Parameters:
413**		sig - caught signal (or zero if not dying on a signal).
414**
415**	Returns:
416**		Does not return.
417**
418**	Side Effects:
419**		- This process ceases to exist.
420*/
421void
422Exit(sig)
423	int sig;
424{
425	if (sig > 0)
426		syslog(LOG_ERR, "going down on signal %d", sig);
427	else
428		syslog(LOG_ERR, "going down with fatal error");
429	BpfClose();
430	exit(1);
431}
432
433/*
434**  ReConfig -- Get new list of boot files and reread config files.
435**
436**	Parameters:
437**		None.
438**
439**	Returns:
440**		Nothing.
441**
442**	Side Effects:
443**		- All active connections are dropped.
444**		- List of boot-able files is changed.
445**		- List of clients is changed.
446**
447**	Warnings:
448**		- This routine must be called with SIGHUP blocked.
449*/
450void
451ReConfig(signo)
452	int signo;
453{
454	syslog(LOG_NOTICE, "reconfiguring boot server");
455
456	FreeConns();
457
458	if (GetBootFiles() == 0)
459		Exit(0);
460
461	if (ParseConfig() == 0)
462		Exit(0);
463}
464
465/*
466**  DebugOff -- Turn off debugging.
467**
468**	Parameters:
469**		None.
470**
471**	Returns:
472**		Nothing.
473**
474**	Side Effects:
475**		- Debug file is closed.
476*/
477void
478DebugOff(signo)
479	int signo;
480{
481	if (DbgFp != NULL)
482		(void) fclose(DbgFp);
483
484	DbgFp = NULL;
485}
486
487/*
488**  DebugOn -- Turn on debugging.
489**
490**	Parameters:
491**		None.
492**
493**	Returns:
494**		Nothing.
495**
496**	Side Effects:
497**		- Debug file is opened/truncated if not already opened,
498**		  otherwise do nothing.
499*/
500void
501DebugOn(signo)
502	int signo;
503{
504	if (DbgFp == NULL) {
505		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
506			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
507	}
508}
509