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
57 static void usage(void) __dead2;
58
59 int
main(int argc,char * argv[])60 main(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
272 static void
usage(void)273 usage(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 */
291 void
DoTimeout(void)292 DoTimeout(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
327 CLIENT *
FindClient(RMPCONN * rconn)328 FindClient(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 */
352 void
Exit(int sig)353 Exit(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 */
380 void
ReConfig(int signo __unused)381 ReConfig(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 */
406 void
DebugOff(int signo __unused)407 DebugOff(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 */
428 void
DebugOn(int signo __unused)429 DebugOn(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