rbootd.c revision 90377 
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  "$FreeBSD: head/libexec/rbootd/rbootd.c 90377 2002-02-07 23:57:01Z imp $";
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(void);
76
77int
78main(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			syslog(LOG_NOTICE, "restarted (??)");
155			/* BpfGetIntfName() returns safe names, using %m */
156			syslog(LOG_ERR, "%s", errmsg);
157			Exit(0);
158		}
159	}
160
161	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
162
163	(void) signal(SIGHUP, ReConfig);
164	(void) signal(SIGINT, Exit);
165	(void) signal(SIGTERM, Exit);
166
167	/*
168	 *  Grab our host name and pid.
169	 */
170	if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) {
171		syslog(LOG_ERR, "gethostname: %m");
172		Exit(0);
173	}
174	MyHost[MAXHOSTNAMELEN - 1] = '\0';
175
176	MyPid = getpid();
177
178	/*
179	 *  Write proc's pid to a file.
180	 */
181	{
182		FILE *fp;
183
184		if ((fp = fopen(PidFile, "w")) != NULL) {
185			(void) fprintf(fp, "%d\n", (int) MyPid);
186			(void) fclose(fp);
187		} else {
188			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
189		}
190	}
191
192	/*
193	 *  All boot files are relative to the boot directory, we might
194	 *  as well chdir() there to make life easier.
195	 */
196	if (chdir(BootDir) < 0) {
197		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
198		Exit(0);
199	}
200
201	/*
202	 *  Initial configuration.
203	 */
204	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
205	if (GetBootFiles() == 0)		/* get list of boot files */
206		Exit(0);
207	if (ParseConfig() == 0)			/* parse config file */
208		Exit(0);
209
210	/*
211	 *  Open and initialize a BPF device for the appropriate interface.
212	 *  If an error is encountered, a message is displayed and Exit()
213	 *  is called.
214	 */
215	fd = BpfOpen();
216
217	(void) sigsetmask(omask);		/* allow reconfig's */
218
219	/*
220	 *  Main loop: receive a packet, determine where it came from,
221	 *  and if we service this host, call routine to handle request.
222	 */
223	maxfds = fd + 1;
224	FD_ZERO(&rset);
225	FD_SET(fd, &rset);
226	for (;;) {
227		struct timeval timeout;
228		fd_set r;
229		int nsel;
230
231		r = rset;
232
233		if (RmpConns == NULL) {		/* timeout isnt necessary */
234			nsel = select(maxfds, &r, NULL, NULL, NULL);
235		} else {
236			timeout.tv_sec = RMP_TIMEOUT;
237			timeout.tv_usec = 0;
238			nsel = select(maxfds, &r, NULL, NULL, &timeout);
239		}
240
241		if (nsel < 0) {
242			if (errno == EINTR)
243				continue;
244			syslog(LOG_ERR, "select: %m");
245			Exit(0);
246		} else if (nsel == 0) {		/* timeout */
247			DoTimeout();			/* clear stale conns */
248			continue;
249		}
250
251		if (FD_ISSET(fd, &r)) {
252			RMPCONN rconn;
253			CLIENT *client, *FindClient();
254			int doread = 1;
255
256			while (BpfRead(&rconn, doread)) {
257				doread = 0;
258
259				if (DbgFp != NULL)	/* display packet */
260					DispPkt(&rconn,DIR_RCVD);
261
262				omask = sigblock(sigmask(SIGHUP));
263
264				/*
265				 *  If we do not restrict service, set the
266				 *  client to NULL (ProcessPacket() handles
267				 *  this).  Otherwise, check that we can
268				 *  service this host; if not, log a message
269				 *  and ignore the packet.
270				 */
271				if (BootAny) {
272					client = NULL;
273				} else if ((client=FindClient(&rconn))==NULL) {
274					syslog(LOG_INFO,
275					       "%s: boot packet ignored",
276					       EnetStr(&rconn));
277					(void) sigsetmask(omask);
278					continue;
279				}
280
281				ProcessPacket(&rconn,client);
282
283				(void) sigsetmask(omask);
284			}
285		}
286	}
287}
288
289static void
290usage(void)
291{
292	fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
293	exit (1);
294}
295
296/*
297**  DoTimeout -- Free any connections that have timed out.
298**
299**	Parameters:
300**		None.
301**
302**	Returns:
303**		Nothing.
304**
305**	Side Effects:
306**		- Timed out connections in `RmpConns' will be freed.
307*/
308void
309DoTimeout(void)
310{
311	RMPCONN *rtmp;
312	struct timeval now;
313
314	(void) gettimeofday(&now, (struct timezone *)0);
315
316	/*
317	 *  For each active connection, if RMP_TIMEOUT seconds have passed
318	 *  since the last packet was sent, delete the connection.
319	 */
320	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
321		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
322			syslog(LOG_WARNING, "%s: connection timed out (%u)",
323			       EnetStr(rtmp), rtmp->rmp.r_type);
324			RemoveConn(rtmp);
325		}
326}
327
328/*
329**  FindClient -- Find client associated with a packet.
330**
331**	Parameters:
332**		rconn - the new packet.
333**
334**	Returns:
335**		Pointer to client info if found, NULL otherwise.
336**
337**	Side Effects:
338**		None.
339**
340**	Warnings:
341**		- This routine must be called with SIGHUP blocked since
342**		  a reconfigure can invalidate the information returned.
343*/
344
345CLIENT *
346FindClient(RMPCONN *rconn)
347{
348	CLIENT *ctmp;
349
350	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
351		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
352		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
353			break;
354
355	return(ctmp);
356}
357
358/*
359**  Exit -- Log an error message and exit.
360**
361**	Parameters:
362**		sig - caught signal (or zero if not dying on a signal).
363**
364**	Returns:
365**		Does not return.
366**
367**	Side Effects:
368**		- This process ceases to exist.
369*/
370void
371Exit(int sig)
372{
373	if (sig > 0)
374		syslog(LOG_ERR, "going down on signal %d", sig);
375	else
376		syslog(LOG_ERR, "going down with fatal error");
377	BpfClose();
378	exit(1);
379}
380
381/*
382**  ReConfig -- Get new list of boot files and reread config files.
383**
384**	Parameters:
385**		None.
386**
387**	Returns:
388**		Nothing.
389**
390**	Side Effects:
391**		- All active connections are dropped.
392**		- List of boot-able files is changed.
393**		- List of clients is changed.
394**
395**	Warnings:
396**		- This routine must be called with SIGHUP blocked.
397*/
398void
399ReConfig(int signo)
400{
401	syslog(LOG_NOTICE, "reconfiguring boot server");
402
403	FreeConns();
404
405	if (GetBootFiles() == 0)
406		Exit(0);
407
408	if (ParseConfig() == 0)
409		Exit(0);
410}
411
412/*
413**  DebugOff -- Turn off debugging.
414**
415**	Parameters:
416**		None.
417**
418**	Returns:
419**		Nothing.
420**
421**	Side Effects:
422**		- Debug file is closed.
423*/
424void
425DebugOff(int signo)
426{
427	if (DbgFp != NULL)
428		(void) fclose(DbgFp);
429
430	DbgFp = NULL;
431}
432
433/*
434**  DebugOn -- Turn on debugging.
435**
436**	Parameters:
437**		None.
438**
439**	Returns:
440**		Nothing.
441**
442**	Side Effects:
443**		- Debug file is opened/truncated if not already opened,
444**		  otherwise do nothing.
445*/
446void
447DebugOn(int signo)
448{
449	if (DbgFp == NULL) {
450		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
451			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
452	}
453}
454