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. Neither the name of the University nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 *	from: @(#)rbootd.c	8.1 (Berkeley) 6/4/93
38 *
39 * From: Utah Hdr: rbootd.c 3.1 92/07/06
40 * Author: Jeff Forys, University of Utah CSS
41 */
42
43#ifndef lint
44static const char copyright[] =
45"@(#) Copyright (c) 1992, 1993\n\
46	The Regents of the University of California.  All rights reserved.\n";
47#endif /* not lint */
48
49#ifndef lint
50#if 0
51static const char sccsid[] = "@(#)rbootd.c	8.1 (Berkeley) 6/4/93";
52#endif
53#endif /* not lint */
54#include <sys/cdefs.h>
55__FBSDID("$FreeBSD$");
56
57#include <sys/param.h>
58#include <sys/time.h>
59#include <ctype.h>
60#include <err.h>
61#include <errno.h>
62#include <fcntl.h>
63#include <signal.h>
64#include <stdio.h>
65#include <stdlib.h>
66#include <string.h>
67#include <syslog.h>
68#include <unistd.h>
69#include "defs.h"
70
71static void usage(void);
72
73int
74main(int argc, char *argv[])
75{
76	int c, fd, omask, maxfds;
77	fd_set rset;
78
79	/*
80	 *  Close any open file descriptors.
81	 *  Temporarily leave stdin & stdout open for `-d',
82	 *  and stderr open for any pre-syslog error messages.
83	 */
84	{
85		int i, nfds = getdtablesize();
86
87		for (i = 0; i < nfds; i++)
88			if (i != fileno(stdin) && i != fileno(stdout) &&
89			    i != fileno(stderr))
90				(void) close(i);
91	}
92
93	/*
94	 *  Parse any arguments.
95	 */
96	while ((c = getopt(argc, argv, "adi:")) != -1)
97		switch(c) {
98		    case 'a':
99			BootAny++;
100			break;
101		    case 'd':
102			DebugFlg++;
103			break;
104		    case 'i':
105			IntfName = optarg;
106			break;
107		    default:
108			usage();
109		}
110	for (; optind < argc; optind++) {
111		if (ConfigFile == NULL)
112			ConfigFile = argv[optind];
113		else {
114			warnx("too many config files (`%s' ignored)",
115			    argv[optind]);
116		}
117	}
118
119	if (ConfigFile == NULL)			/* use default config file */
120		ConfigFile = DfltConfig;
121
122	if (DebugFlg) {
123		DbgFp = stdout;				/* output to stdout */
124
125		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
126		(void) signal(SIGUSR2, SIG_IGN);
127		(void) fclose(stderr);			/* finished with it */
128	} else {
129		if (daemon(0, 0))
130			err(1, "can't detach from terminal");
131
132		(void) signal(SIGUSR1, DebugOn);
133		(void) signal(SIGUSR2, DebugOff);
134	}
135
136	openlog("rbootd", LOG_PID, LOG_DAEMON);
137
138	/*
139	 *  If no interface was specified, get one now.
140	 *
141	 *  This is convoluted because we want to get the default interface
142	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
143	 *  runs into an error, it will return a syslog-able error message
144	 *  (in `errmsg') which will be displayed here.
145	 */
146	if (IntfName == NULL) {
147		char *errmsg;
148
149		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
150			/* Backslash to avoid trigraph '??)'. */
151			syslog(LOG_NOTICE, "restarted (?\?)");
152			/* BpfGetIntfName() returns safe names, using %m */
153			syslog(LOG_ERR, "%s", errmsg);
154			Exit(0);
155		}
156	}
157
158	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
159
160	(void) signal(SIGHUP, ReConfig);
161	(void) signal(SIGINT, Exit);
162	(void) signal(SIGTERM, Exit);
163
164	/*
165	 *  Grab our host name and pid.
166	 */
167	if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) {
168		syslog(LOG_ERR, "gethostname: %m");
169		Exit(0);
170	}
171	MyHost[MAXHOSTNAMELEN - 1] = '\0';
172
173	MyPid = getpid();
174
175	/*
176	 *  Write proc's pid to a file.
177	 */
178	{
179		FILE *fp;
180
181		if ((fp = fopen(PidFile, "w")) != NULL) {
182			(void) fprintf(fp, "%d\n", (int) MyPid);
183			(void) fclose(fp);
184		} else {
185			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
186		}
187	}
188
189	/*
190	 *  All boot files are relative to the boot directory, we might
191	 *  as well chdir() there to make life easier.
192	 */
193	if (chdir(BootDir) < 0) {
194		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
195		Exit(0);
196	}
197
198	/*
199	 *  Initial configuration.
200	 */
201	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
202	if (GetBootFiles() == 0)		/* get list of boot files */
203		Exit(0);
204	if (ParseConfig() == 0)			/* parse config file */
205		Exit(0);
206
207	/*
208	 *  Open and initialize a BPF device for the appropriate interface.
209	 *  If an error is encountered, a message is displayed and Exit()
210	 *  is called.
211	 */
212	fd = BpfOpen();
213
214	(void) sigsetmask(omask);		/* allow reconfig's */
215
216	/*
217	 *  Main loop: receive a packet, determine where it came from,
218	 *  and if we service this host, call routine to handle request.
219	 */
220	maxfds = fd + 1;
221	FD_ZERO(&rset);
222	FD_SET(fd, &rset);
223	for (;;) {
224		struct timeval timeout;
225		fd_set r;
226		int nsel;
227
228		r = rset;
229
230		if (RmpConns == NULL) {		/* timeout isn't necessary */
231			nsel = select(maxfds, &r, NULL, NULL, NULL);
232		} else {
233			timeout.tv_sec = RMP_TIMEOUT;
234			timeout.tv_usec = 0;
235			nsel = select(maxfds, &r, NULL, NULL, &timeout);
236		}
237
238		if (nsel < 0) {
239			if (errno == EINTR)
240				continue;
241			syslog(LOG_ERR, "select: %m");
242			Exit(0);
243		} else if (nsel == 0) {		/* timeout */
244			DoTimeout();			/* clear stale conns */
245			continue;
246		}
247
248		if (FD_ISSET(fd, &r)) {
249			RMPCONN rconn;
250			CLIENT *client, *FindClient();
251			int doread = 1;
252
253			while (BpfRead(&rconn, doread)) {
254				doread = 0;
255
256				if (DbgFp != NULL)	/* display packet */
257					DispPkt(&rconn,DIR_RCVD);
258
259				omask = sigblock(sigmask(SIGHUP));
260
261				/*
262				 *  If we do not restrict service, set the
263				 *  client to NULL (ProcessPacket() handles
264				 *  this).  Otherwise, check that we can
265				 *  service this host; if not, log a message
266				 *  and ignore the packet.
267				 */
268				if (BootAny) {
269					client = NULL;
270				} else if ((client=FindClient(&rconn))==NULL) {
271					syslog(LOG_INFO,
272					       "%s: boot packet ignored",
273					       EnetStr(&rconn));
274					(void) sigsetmask(omask);
275					continue;
276				}
277
278				ProcessPacket(&rconn,client);
279
280				(void) sigsetmask(omask);
281			}
282		}
283	}
284}
285
286static void
287usage(void)
288{
289	fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
290	exit (1);
291}
292
293/*
294**  DoTimeout -- Free any connections that have timed out.
295**
296**	Parameters:
297**		None.
298**
299**	Returns:
300**		Nothing.
301**
302**	Side Effects:
303**		- Timed out connections in `RmpConns' will be freed.
304*/
305void
306DoTimeout(void)
307{
308	RMPCONN *rtmp;
309	time_t now;
310
311	/*
312	 *  For each active connection, if RMP_TIMEOUT seconds have passed
313	 *  since the last packet was sent, delete the connection.
314	 */
315	now = time(NULL);
316	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
317		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now) {
318			syslog(LOG_WARNING, "%s: connection timed out (%u)",
319			       EnetStr(rtmp), rtmp->rmp.r_type);
320			RemoveConn(rtmp);
321		}
322}
323
324/*
325**  FindClient -- Find client associated with a packet.
326**
327**	Parameters:
328**		rconn - the new packet.
329**
330**	Returns:
331**		Pointer to client info if found, NULL otherwise.
332**
333**	Side Effects:
334**		None.
335**
336**	Warnings:
337**		- This routine must be called with SIGHUP blocked since
338**		  a reconfigure can invalidate the information returned.
339*/
340
341CLIENT *
342FindClient(RMPCONN *rconn)
343{
344	CLIENT *ctmp;
345
346	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
347		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
348		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
349			break;
350
351	return(ctmp);
352}
353
354/*
355**  Exit -- Log an error message and exit.
356**
357**	Parameters:
358**		sig - caught signal (or zero if not dying on a signal).
359**
360**	Returns:
361**		Does not return.
362**
363**	Side Effects:
364**		- This process ceases to exist.
365*/
366void
367Exit(int sig)
368{
369	if (sig > 0)
370		syslog(LOG_ERR, "going down on signal %d", sig);
371	else
372		syslog(LOG_ERR, "going down with fatal error");
373	BpfClose();
374	exit(1);
375}
376
377/*
378**  ReConfig -- Get new list of boot files and reread config files.
379**
380**	Parameters:
381**		None.
382**
383**	Returns:
384**		Nothing.
385**
386**	Side Effects:
387**		- All active connections are dropped.
388**		- List of boot-able files is changed.
389**		- List of clients is changed.
390**
391**	Warnings:
392**		- This routine must be called with SIGHUP blocked.
393*/
394void
395ReConfig(int signo __unused)
396{
397	syslog(LOG_NOTICE, "reconfiguring boot server");
398
399	FreeConns();
400
401	if (GetBootFiles() == 0)
402		Exit(0);
403
404	if (ParseConfig() == 0)
405		Exit(0);
406}
407
408/*
409**  DebugOff -- Turn off debugging.
410**
411**	Parameters:
412**		None.
413**
414**	Returns:
415**		Nothing.
416**
417**	Side Effects:
418**		- Debug file is closed.
419*/
420void
421DebugOff(int signo __unused)
422{
423	if (DbgFp != NULL)
424		(void) fclose(DbgFp);
425
426	DbgFp = NULL;
427}
428
429/*
430**  DebugOn -- Turn on debugging.
431**
432**	Parameters:
433**		None.
434**
435**	Returns:
436**		Nothing.
437**
438**	Side Effects:
439**		- Debug file is opened/truncated if not already opened,
440**		  otherwise do nothing.
441*/
442void
443DebugOn(int signo __unused)
444{
445	if (DbgFp == NULL) {
446		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
447			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
448	}
449}
450