rbootd.c revision 45422 
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
48static 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
55static const char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
56#endif
57static const char rcsid[] =
58	"$Id: rbootd.c,v 1.9 1997/11/24 07:33:41 charnier Exp $";
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
75static void usage __P((void));
76
77int
78main(argc, argv)
79	int argc;
80	char *argv[];
81{
82	int c, fd, omask, maxfds;
83	fd_set rset;
84
85	/*
86	 *  Close any open file descriptors.
87	 *  Temporarily leave stdin & stdout open for `-d',
88	 *  and stderr open for any pre-syslog error messages.
89	 */
90	{
91		int i, nfds = getdtablesize();
92
93		for (i = 0; i < nfds; i++)
94			if (i != fileno(stdin) && i != fileno(stdout) &&
95			    i != fileno(stderr))
96				(void) close(i);
97	}
98
99	/*
100	 *  Parse any arguments.
101	 */
102	while ((c = getopt(argc, argv, "adi:")) != -1)
103		switch(c) {
104		    case 'a':
105			BootAny++;
106			break;
107		    case 'd':
108			DebugFlg++;
109			break;
110		    case 'i':
111			IntfName = optarg;
112			break;
113		    default:
114			usage();
115		}
116	for (; optind < argc; optind++) {
117		if (ConfigFile == NULL)
118			ConfigFile = argv[optind];
119		else {
120			warnx("too many config files (`%s' ignored)",
121			    argv[optind]);
122		}
123	}
124
125	if (ConfigFile == NULL)			/* use default config file */
126		ConfigFile = DfltConfig;
127
128	if (DebugFlg) {
129		DbgFp = stdout;				/* output to stdout */
130
131		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
132		(void) signal(SIGUSR2, SIG_IGN);
133		(void) fclose(stderr);			/* finished with it */
134	} else {
135		if (daemon(0, 0))
136			err(1, "can't detach from terminal");
137
138		(void) signal(SIGUSR1, DebugOn);
139		(void) signal(SIGUSR2, DebugOff);
140	}
141
142	openlog("rbootd", LOG_PID, LOG_DAEMON);
143
144	/*
145	 *  If no interface was specified, get one now.
146	 *
147	 *  This is convoluted because we want to get the default interface
148	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
149	 *  runs into an error, it will return a syslog-able error message
150	 *  (in `errmsg') which will be displayed here.
151	 */
152	if (IntfName == NULL) {
153		char *errmsg;
154
155		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
156			syslog(LOG_NOTICE, "restarted (??)");
157			syslog(LOG_ERR, 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
290static void
291usage()
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*/
309void
310DoTimeout()
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
346CLIENT *
347FindClient(rconn)
348	RMPCONN *rconn;
349{
350	CLIENT *ctmp;
351
352	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
353		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
354		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
355			break;
356
357	return(ctmp);
358}
359
360/*
361**  Exit -- Log an error message and exit.
362**
363**	Parameters:
364**		sig - caught signal (or zero if not dying on a signal).
365**
366**	Returns:
367**		Does not return.
368**
369**	Side Effects:
370**		- This process ceases to exist.
371*/
372void
373Exit(sig)
374	int sig;
375{
376	if (sig > 0)
377		syslog(LOG_ERR, "going down on signal %d", sig);
378	else
379		syslog(LOG_ERR, "going down with fatal error");
380	BpfClose();
381	exit(1);
382}
383
384/*
385**  ReConfig -- Get new list of boot files and reread config files.
386**
387**	Parameters:
388**		None.
389**
390**	Returns:
391**		Nothing.
392**
393**	Side Effects:
394**		- All active connections are dropped.
395**		- List of boot-able files is changed.
396**		- List of clients is changed.
397**
398**	Warnings:
399**		- This routine must be called with SIGHUP blocked.
400*/
401void
402ReConfig(signo)
403	int signo;
404{
405	syslog(LOG_NOTICE, "reconfiguring boot server");
406
407	FreeConns();
408
409	if (GetBootFiles() == 0)
410		Exit(0);
411
412	if (ParseConfig() == 0)
413		Exit(0);
414}
415
416/*
417**  DebugOff -- Turn off debugging.
418**
419**	Parameters:
420**		None.
421**
422**	Returns:
423**		Nothing.
424**
425**	Side Effects:
426**		- Debug file is closed.
427*/
428void
429DebugOff(signo)
430	int signo;
431{
432	if (DbgFp != NULL)
433		(void) fclose(DbgFp);
434
435	DbgFp = NULL;
436}
437
438/*
439**  DebugOn -- Turn on debugging.
440**
441**	Parameters:
442**		None.
443**
444**	Returns:
445**		Nothing.
446**
447**	Side Effects:
448**		- Debug file is opened/truncated if not already opened,
449**		  otherwise do nothing.
450*/
451void
452DebugOn(signo)
453	int signo;
454{
455	if (DbgFp == NULL) {
456		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
457			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
458	}
459}
460