1 /* $NetBSD: rbootd.c,v 1.24 2017/05/04 16:26:09 sevan Exp $ */
2
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: @(#)rbootd.c 8.1 (Berkeley) 6/4/93
40 *
41 * From: Utah Hdr: rbootd.c 3.1 92/07/06
42 * Author: Jeff Forys, University of Utah CSS
43 */
44
45 #include <sys/cdefs.h>
46 #ifndef lint
47 __COPYRIGHT("@(#) Copyright (c) 1992, 1993\
48 The Regents of the University of California. All rights reserved.");
49 #endif /* not lint */
50
51 #ifndef lint
52 #if 0
53 static char sccsid[] = "@(#)rbootd.c 8.1 (Berkeley) 6/4/93";
54 #else
55 __RCSID("$NetBSD: rbootd.c,v 1.24 2017/05/04 16:26:09 sevan Exp $");
56 #endif
57 #endif /* not lint */
58
59 #include <sys/param.h>
60 #include <sys/time.h>
61 #include <poll.h>
62 #include <err.h>
63 #include <errno.h>
64 #include <fcntl.h>
65 #include <signal.h>
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <string.h>
69 #include <syslog.h>
70 #include <unistd.h>
71 #include <util.h>
72 #include "defs.h"
73
74 int
main(int argc,char * argv[])75 main(int argc, char *argv[])
76 {
77 int c, fd, omask;
78 struct pollfd set[1];
79
80 /*
81 * Close any open file descriptors.
82 * Temporarily leave stdin & stdout open for `-d',
83 * and stderr open for any pre-syslog error messages.
84 */
85 {
86 int i, nfds = getdtablesize();
87
88 for (i = 0; i < nfds; i++)
89 if (i != STDIN_FILENO && i != STDOUT_FILENO &&
90 i != STDERR_FILENO)
91 (void) close(i);
92 }
93
94 /*
95 * Parse any arguments.
96 */
97 while ((c = getopt(argc, argv, "adi:")) != -1)
98 switch(c) {
99 case 'a':
100 BootAny++;
101 break;
102 case 'd':
103 DebugFlg++;
104 break;
105 case 'i':
106 IntfName = optarg;
107 break;
108 }
109 for (; optind < argc; optind++) {
110 if (ConfigFile == NULL)
111 ConfigFile = argv[optind];
112 else {
113 warnx("too many config files (`%s' ignored)",
114 argv[optind]);
115 }
116 }
117
118 if (ConfigFile == NULL) /* use default config file */
119 ConfigFile = DfltConfig;
120
121 if (DebugFlg) {
122 DbgFp = stdout; /* output to stdout */
123
124 (void) signal(SIGUSR1, SIG_IGN); /* dont muck w/DbgFp */
125 (void) signal(SIGUSR2, SIG_IGN);
126 (void) fclose(stderr); /* finished with it */
127 } else {
128 if (daemon(0, 0))
129 err(1, "can't detach from terminal");
130 pidfile(NULL);
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 syslog(LOG_ERR, "%s", errmsg);
153 Exit(0);
154 }
155 }
156
157 syslog(LOG_NOTICE, "restarted (%s)", IntfName);
158
159 (void) signal(SIGHUP, ReConfig);
160 (void) signal(SIGINT, Exit);
161 (void) signal(SIGTERM, Exit);
162
163 /*
164 * Grab our host name and pid.
165 */
166 if (gethostname(MyHost, sizeof MyHost) < 0) {
167 syslog(LOG_ERR, "gethostname: %m");
168 Exit(0);
169 }
170 MyHost[sizeof(MyHost) - 1] = '\0';
171
172 /*
173 * All boot files are relative to the boot directory, we might
174 * as well chdir() there to make life easier.
175 */
176 if (chdir(BootDir) < 0) {
177 syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
178 Exit(0);
179 }
180
181 /*
182 * Initial configuration.
183 */
184 omask = sigblock(sigmask(SIGHUP)); /* prevent reconfig's */
185 if (GetBootFiles() == 0) /* get list of boot files */
186 Exit(0);
187 if (ParseConfig() == 0) /* parse config file */
188 Exit(0);
189
190 /*
191 * Open and initialize a BPF device for the appropriate interface.
192 * If an error is encountered, a message is displayed and Exit()
193 * is called.
194 */
195 fd = BpfOpen();
196
197 (void) sigsetmask(omask); /* allow reconfig's */
198
199 /*
200 * Main loop: receive a packet, determine where it came from,
201 * and if we service this host, call routine to handle request.
202 */
203 set[0].fd = fd;
204 set[0].events = POLLIN;
205 for (;;) {
206 int nsel;
207
208 nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);
209
210 if (nsel < 0) {
211 if (errno == EINTR)
212 continue;
213 syslog(LOG_ERR, "poll: %m");
214 Exit(0);
215 } else if (nsel == 0) { /* timeout */
216 DoTimeout(); /* clear stale conns */
217 continue;
218 }
219
220 if (set[0].revents & POLLIN) {
221 RMPCONN rconn;
222 CLIENT *client;
223 int doread = 1;
224
225 while (BpfRead(&rconn, doread)) {
226 doread = 0;
227
228 if (DbgFp != NULL) /* display packet */
229 DispPkt(&rconn,DIR_RCVD);
230
231 omask = sigblock(sigmask(SIGHUP));
232
233 /*
234 * If we do not restrict service, set the
235 * client to NULL (ProcessPacket() handles
236 * this). Otherwise, check that we can
237 * service this host; if not, log a message
238 * and ignore the packet.
239 */
240 if (BootAny) {
241 client = NULL;
242 } else if ((client=FindClient(&rconn))==NULL) {
243 syslog(LOG_INFO,
244 "%s: boot packet ignored",
245 EnetStr(&rconn));
246 (void) sigsetmask(omask);
247 continue;
248 }
249
250 ProcessPacket(&rconn,client);
251
252 (void) sigsetmask(omask);
253 }
254 }
255 }
256 }
257
258 /*
259 ** DoTimeout -- Free any connections that have timed out.
260 **
261 ** Parameters:
262 ** None.
263 **
264 ** Returns:
265 ** Nothing.
266 **
267 ** Side Effects:
268 ** - Timed out connections in `RmpConns' will be freed.
269 */
270 void
DoTimeout(void)271 DoTimeout(void)
272 {
273 RMPCONN *rtmp;
274 struct timeval now;
275
276 (void) gettimeofday(&now, (struct timezone *)0);
277
278 /*
279 * For each active connection, if RMP_TIMEOUT seconds have passed
280 * since the last packet was sent, delete the connection.
281 */
282 for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
283 if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
284 syslog(LOG_WARNING, "%s: connection timed out (%u)",
285 EnetStr(rtmp), rtmp->rmp.r_type);
286 RemoveConn(rtmp);
287 }
288 }
289
290 /*
291 ** FindClient -- Find client associated with a packet.
292 **
293 ** Parameters:
294 ** rconn - the new packet.
295 **
296 ** Returns:
297 ** Pointer to client info if found, NULL otherwise.
298 **
299 ** Side Effects:
300 ** None.
301 **
302 ** Warnings:
303 ** - This routine must be called with SIGHUP blocked since
304 ** a reconfigure can invalidate the information returned.
305 */
306
307 CLIENT *
FindClient(RMPCONN * rconn)308 FindClient(RMPCONN *rconn)
309 {
310 CLIENT *ctmp;
311
312 for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
313 if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
314 (char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
315 break;
316
317 return(ctmp);
318 }
319
320 /*
321 ** Exit -- Log an error message and exit.
322 **
323 ** Parameters:
324 ** sig - caught signal (or zero if not dying on a signal).
325 **
326 ** Returns:
327 ** Does not return.
328 **
329 ** Side Effects:
330 ** - This process ceases to exist.
331 */
332 void
Exit(int sig)333 Exit(int sig)
334 {
335 if (sig > 0)
336 syslog(LOG_ERR, "going down on signal %d", sig);
337 else
338 syslog(LOG_ERR, "going down with fatal error");
339 BpfClose();
340 exit(1);
341 }
342
343 /*
344 ** ReConfig -- Get new list of boot files and reread config files.
345 **
346 ** Parameters:
347 ** None.
348 **
349 ** Returns:
350 ** Nothing.
351 **
352 ** Side Effects:
353 ** - All active connections are dropped.
354 ** - List of boot-able files is changed.
355 ** - List of clients is changed.
356 **
357 ** Warnings:
358 ** - This routine must be called with SIGHUP blocked.
359 */
360 void
ReConfig(int signo)361 ReConfig(int signo)
362 {
363 syslog(LOG_NOTICE, "reconfiguring boot server");
364
365 FreeConns();
366
367 if (GetBootFiles() == 0)
368 Exit(0);
369
370 if (ParseConfig() == 0)
371 Exit(0);
372 }
373
374 /*
375 ** DebugOff -- Turn off debugging.
376 **
377 ** Parameters:
378 ** None.
379 **
380 ** Returns:
381 ** Nothing.
382 **
383 ** Side Effects:
384 ** - Debug file is closed.
385 */
386 void
DebugOff(int signo)387 DebugOff(int signo)
388 {
389 if (DbgFp != NULL)
390 (void) fclose(DbgFp);
391
392 DbgFp = NULL;
393 }
394
395 /*
396 ** DebugOn -- Turn on debugging.
397 **
398 ** Parameters:
399 ** None.
400 **
401 ** Returns:
402 ** Nothing.
403 **
404 ** Side Effects:
405 ** - Debug file is opened/truncated if not already opened,
406 ** otherwise do nothing.
407 */
408 void
DebugOn(int signo)409 DebugOn(int signo)
410 {
411 if (DbgFp == NULL) {
412 if ((DbgFp = fopen(DbgFile, "w")) == NULL)
413 syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
414 }
415 }
416