1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * From: Utah Hdr: rbootd.c 3.1 92/07/06
40 * Author: Jeff Forys, University of Utah CSS
41 */
42
43#include <sys/param.h>
44#include <sys/time.h>
45#include <ctype.h>
46#include <err.h>
47#include <errno.h>
48#include <fcntl.h>
49#include <signal.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <syslog.h>
54#include <unistd.h>
55#include "defs.h"
56
57static void usage(void) __dead2;
58
59int
60main(int argc, char *argv[])
61{
62	int c, fd, omask, maxfds;
63	fd_set rset;
64
65	/*
66	 *  Close any open file descriptors.
67	 *  Temporarily leave stdin & stdout open for `-d',
68	 *  and stderr open for any pre-syslog error messages.
69	 */
70	{
71		int i, nfds = getdtablesize();
72
73		for (i = 0; i < nfds; i++)
74			if (i != fileno(stdin) && i != fileno(stdout) &&
75			    i != fileno(stderr))
76				(void) close(i);
77	}
78
79	/*
80	 *  Parse any arguments.
81	 */
82	while ((c = getopt(argc, argv, "adi:")) != -1)
83		switch(c) {
84		    case 'a':
85			BootAny++;
86			break;
87		    case 'd':
88			DebugFlg++;
89			break;
90		    case 'i':
91			IntfName = optarg;
92			break;
93		    default:
94			usage();
95		}
96	for (; optind < argc; optind++) {
97		if (ConfigFile == NULL)
98			ConfigFile = argv[optind];
99		else {
100			warnx("too many config files (`%s' ignored)",
101			    argv[optind]);
102		}
103	}
104
105	if (ConfigFile == NULL)			/* use default config file */
106		ConfigFile = DfltConfig;
107
108	if (DebugFlg) {
109		DbgFp = stdout;				/* output to stdout */
110
111		(void) signal(SIGUSR1, SIG_IGN);	/* dont muck w/DbgFp */
112		(void) signal(SIGUSR2, SIG_IGN);
113		(void) fclose(stderr);			/* finished with it */
114	} else {
115		if (daemon(0, 0))
116			err(1, "can't detach from terminal");
117
118		(void) signal(SIGUSR1, DebugOn);
119		(void) signal(SIGUSR2, DebugOff);
120	}
121
122	openlog("rbootd", LOG_PID, LOG_DAEMON);
123
124	/*
125	 *  If no interface was specified, get one now.
126	 *
127	 *  This is convoluted because we want to get the default interface
128	 *  name for the syslog("restarted") message.  If BpfGetIntfName()
129	 *  runs into an error, it will return a syslog-able error message
130	 *  (in `errmsg') which will be displayed here.
131	 */
132	if (IntfName == NULL) {
133		char *errmsg;
134
135		if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
136			/* Backslash to avoid trigraph '??)'. */
137			syslog(LOG_NOTICE, "restarted (?\?)");
138			/* BpfGetIntfName() returns safe names, using %m */
139			syslog(LOG_ERR, "%s", errmsg);
140			Exit(0);
141		}
142	}
143
144	syslog(LOG_NOTICE, "restarted (%s)", IntfName);
145
146	(void) signal(SIGHUP, ReConfig);
147	(void) signal(SIGINT, Exit);
148	(void) signal(SIGTERM, Exit);
149
150	/*
151	 *  Grab our host name and pid.
152	 */
153	if (gethostname(MyHost, MAXHOSTNAMELEN - 1) < 0) {
154		syslog(LOG_ERR, "gethostname: %m");
155		Exit(0);
156	}
157	MyHost[MAXHOSTNAMELEN - 1] = '\0';
158
159	MyPid = getpid();
160
161	/*
162	 *  Write proc's pid to a file.
163	 */
164	{
165		FILE *fp;
166
167		if ((fp = fopen(PidFile, "w")) != NULL) {
168			(void) fprintf(fp, "%d\n", (int) MyPid);
169			(void) fclose(fp);
170		} else {
171			syslog(LOG_WARNING, "fopen: failed (%s)", PidFile);
172		}
173	}
174
175	/*
176	 *  All boot files are relative to the boot directory, we might
177	 *  as well chdir() there to make life easier.
178	 */
179	if (chdir(BootDir) < 0) {
180		syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
181		Exit(0);
182	}
183
184	/*
185	 *  Initial configuration.
186	 */
187	omask = sigblock(sigmask(SIGHUP));	/* prevent reconfig's */
188	if (GetBootFiles() == 0)		/* get list of boot files */
189		Exit(0);
190	if (ParseConfig() == 0)			/* parse config file */
191		Exit(0);
192
193	/*
194	 *  Open and initialize a BPF device for the appropriate interface.
195	 *  If an error is encountered, a message is displayed and Exit()
196	 *  is called.
197	 */
198	fd = BpfOpen();
199
200	(void) sigsetmask(omask);		/* allow reconfig's */
201
202	/*
203	 *  Main loop: receive a packet, determine where it came from,
204	 *  and if we service this host, call routine to handle request.
205	 */
206	maxfds = fd + 1;
207	FD_ZERO(&rset);
208	FD_SET(fd, &rset);
209	for (;;) {
210		struct timeval timeout;
211		fd_set r;
212		int nsel;
213
214		r = rset;
215
216		if (RmpConns == NULL) {		/* timeout isn't necessary */
217			nsel = select(maxfds, &r, NULL, NULL, NULL);
218		} else {
219			timeout.tv_sec = RMP_TIMEOUT;
220			timeout.tv_usec = 0;
221			nsel = select(maxfds, &r, NULL, NULL, &timeout);
222		}
223
224		if (nsel < 0) {
225			if (errno == EINTR)
226				continue;
227			syslog(LOG_ERR, "select: %m");
228			Exit(0);
229		} else if (nsel == 0) {		/* timeout */
230			DoTimeout();			/* clear stale conns */
231			continue;
232		}
233
234		if (FD_ISSET(fd, &r)) {
235			RMPCONN rconn;
236			CLIENT *client;
237			int doread = 1;
238
239			while (BpfRead(&rconn, doread)) {
240				doread = 0;
241
242				if (DbgFp != NULL)	/* display packet */
243					DispPkt(&rconn,DIR_RCVD);
244
245				omask = sigblock(sigmask(SIGHUP));
246
247				/*
248				 *  If we do not restrict service, set the
249				 *  client to NULL (ProcessPacket() handles
250				 *  this).  Otherwise, check that we can
251				 *  service this host; if not, log a message
252				 *  and ignore the packet.
253				 */
254				if (BootAny) {
255					client = NULL;
256				} else if ((client=FindClient(&rconn))==NULL) {
257					syslog(LOG_INFO,
258					       "%s: boot packet ignored",
259					       EnetStr(&rconn));
260					(void) sigsetmask(omask);
261					continue;
262				}
263
264				ProcessPacket(&rconn,client);
265
266				(void) sigsetmask(omask);
267			}
268		}
269	}
270}
271
272static void
273usage(void)
274{
275	fprintf(stderr, "usage: rbootd [-ad] [-i interface] [config_file]\n");
276	exit (1);
277}
278
279/*
280**  DoTimeout -- Free any connections that have timed out.
281**
282**	Parameters:
283**		None.
284**
285**	Returns:
286**		Nothing.
287**
288**	Side Effects:
289**		- Timed out connections in `RmpConns' will be freed.
290*/
291void
292DoTimeout(void)
293{
294	RMPCONN *rtmp;
295	time_t now;
296
297	/*
298	 *  For each active connection, if RMP_TIMEOUT seconds have passed
299	 *  since the last packet was sent, delete the connection.
300	 */
301	now = time(NULL);
302	for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
303		if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now) {
304			syslog(LOG_WARNING, "%s: connection timed out (%u)",
305			       EnetStr(rtmp), rtmp->rmp.r_type);
306			RemoveConn(rtmp);
307		}
308}
309
310/*
311**  FindClient -- Find client associated with a packet.
312**
313**	Parameters:
314**		rconn - the new packet.
315**
316**	Returns:
317**		Pointer to client info if found, NULL otherwise.
318**
319**	Side Effects:
320**		None.
321**
322**	Warnings:
323**		- This routine must be called with SIGHUP blocked since
324**		  a reconfigure can invalidate the information returned.
325*/
326
327CLIENT *
328FindClient(RMPCONN *rconn)
329{
330	CLIENT *ctmp;
331
332	for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
333		if (bcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
334		         (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
335			break;
336
337	return(ctmp);
338}
339
340/*
341**  Exit -- Log an error message and exit.
342**
343**	Parameters:
344**		sig - caught signal (or zero if not dying on a signal).
345**
346**	Returns:
347**		Does not return.
348**
349**	Side Effects:
350**		- This process ceases to exist.
351*/
352void
353Exit(int sig)
354{
355	if (sig > 0)
356		syslog(LOG_ERR, "going down on signal %d", sig);
357	else
358		syslog(LOG_ERR, "going down with fatal error");
359	BpfClose();
360	exit(1);
361}
362
363/*
364**  ReConfig -- Get new list of boot files and reread config files.
365**
366**	Parameters:
367**		None.
368**
369**	Returns:
370**		Nothing.
371**
372**	Side Effects:
373**		- All active connections are dropped.
374**		- List of boot-able files is changed.
375**		- List of clients is changed.
376**
377**	Warnings:
378**		- This routine must be called with SIGHUP blocked.
379*/
380void
381ReConfig(int signo __unused)
382{
383	syslog(LOG_NOTICE, "reconfiguring boot server");
384
385	FreeConns();
386
387	if (GetBootFiles() == 0)
388		Exit(0);
389
390	if (ParseConfig() == 0)
391		Exit(0);
392}
393
394/*
395**  DebugOff -- Turn off debugging.
396**
397**	Parameters:
398**		None.
399**
400**	Returns:
401**		Nothing.
402**
403**	Side Effects:
404**		- Debug file is closed.
405*/
406void
407DebugOff(int signo __unused)
408{
409	if (DbgFp != NULL)
410		(void) fclose(DbgFp);
411
412	DbgFp = NULL;
413}
414
415/*
416**  DebugOn -- Turn on debugging.
417**
418**	Parameters:
419**		None.
420**
421**	Returns:
422**		Nothing.
423**
424**	Side Effects:
425**		- Debug file is opened/truncated if not already opened,
426**		  otherwise do nothing.
427*/
428void
429DebugOn(int signo __unused)
430{
431	if (DbgFp == NULL) {
432		if ((DbgFp = fopen(DbgFile, "w")) == NULL)
433			syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
434	}
435}
436