xref: /dragonfly/usr.sbin/ypserv/yp_main.c (revision 49781055) 
1 /*
2  * Copyright (c) 1995
3  *	Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by Bill Paul.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD: src/usr.sbin/ypserv/yp_main.c,v 1.21.2.3 2002/02/15 00:47:00 des Exp $
33  * $DragonFly: src/usr.sbin/ypserv/yp_main.c,v 1.5 2005/11/24 22:23:02 swildner Exp $
34  */
35 
36 /*
37  * ypserv startup function.
38  * We need out own main() since we have to do some additional work
39  * that rpcgen won't do for us. Most of this file was generated using
40  * rpcgen.new, and later modified.
41  */
42 
43 #include "yp.h"
44 #include <err.h>
45 #include <errno.h>
46 #include <memory.h>
47 #include <stdio.h>
48 #include <signal.h>
49 #include <stdlib.h> /* getenv, exit */
50 #include <string.h> /* strcmp */
51 #include <syslog.h>
52 #include <unistd.h>
53 #include <rpc/pmap_clnt.h> /* for pmap_unset */
54 #ifdef __cplusplus
55 #include <sysent.h> /* getdtablesize, open */
56 #endif /* __cplusplus */
57 #include <sys/socket.h>
58 #include <netinet/in.h>
59 #include <sys/wait.h>
60 #include "yp_extern.h"
61 #include <rpc/rpc.h>
62 
63 #ifndef SIG_PF
64 #define	SIG_PF void(*)(int)
65 #endif
66 
67 #define	_RPCSVC_CLOSEDOWN 120
68 int _rpcpmstart;		/* Started by a port monitor ? */
69 static int _rpcfdtype;
70 		 /* Whether Stream or Datagram ? */
71 	/* States a server can be in wrt request */
72 
73 #define	_IDLE 0
74 #define	_SERVED 1
75 #define	_SERVING 2
76 
77 extern void ypprog_1(struct svc_req *, SVCXPRT *);
78 extern void ypprog_2(struct svc_req *, SVCXPRT *);
79 extern int _rpc_dtablesize(void);
80 extern int _rpcsvcstate;	 /* Set when a request is serviced */
81 char *progname = "ypserv";
82 char *yp_dir = _PATH_YP;
83 /*int debug = 0;*/
84 int do_dns = 0;
85 int resfd;
86 
87 static void
88 _msgout(char *msg)
89 {
90 	if (debug) {
91 		if (_rpcpmstart)
92 			syslog(LOG_ERR, "%s", msg);
93 		else
94 			warnx("%s", msg);
95 	} else
96 		syslog(LOG_ERR, "%s", msg);
97 }
98 
99 pid_t	yp_pid;
100 
101 static void
102 yp_svc_run(void)
103 {
104 #ifdef FD_SETSIZE
105 	fd_set readfds;
106 #else
107 	int readfds;
108 #endif /* def FD_SETSIZE */
109 	extern int forked;
110 	int fd_setsize = _rpc_dtablesize();
111 	struct timeval timeout;
112 
113 	/* Establish the identity of the parent ypserv process. */
114 	yp_pid = getpid();
115 
116 	for (;;) {
117 #ifdef FD_SETSIZE
118 		readfds = svc_fdset;
119 #else
120 		readfds = svc_fds;
121 #endif /* def FD_SETSIZE */
122 
123 		FD_SET(resfd, &readfds);
124 
125 		timeout.tv_sec = RESOLVER_TIMEOUT;
126 		timeout.tv_usec = 0;
127 		switch (select(fd_setsize, &readfds, NULL, NULL,
128 			       &timeout)) {
129 		case -1:
130 			if (errno == EINTR) {
131 				continue;
132 			}
133 			warn("svc_run: - select failed");
134 			return;
135 		case 0:
136 			if (getpid() == yp_pid)
137 				yp_prune_dnsq();
138 			break;
139 		default:
140 			if (getpid() == yp_pid) {
141 				if (FD_ISSET(resfd, &readfds)) {
142 					yp_run_dnsq();
143 					FD_CLR(resfd, &readfds);
144 				}
145 				svc_getreqset(&readfds);
146 			}
147 		}
148 		if (yp_pid != getpid())
149 			_exit(0);
150 	}
151 }
152 
153 static void
154 unregister(void)
155 {
156 	pmap_unset(YPPROG, YPVERS);
157 	pmap_unset(YPPROG, YPOLDVERS);
158 }
159 
160 static void
161 reaper(int sig)
162 {
163 	int status;
164 	int saved_errno;
165 
166 	saved_errno = errno;
167 
168 	if (sig == SIGHUP) {
169 		load_securenets();
170 #ifdef DB_CACHE
171 		yp_flush_all();
172 #endif
173 		errno = saved_errno;
174 		return;
175 	}
176 
177 	if (sig == SIGCHLD) {
178 		while (wait3(&status, WNOHANG, NULL) > 0)
179 			children--;
180 	} else {
181 		unregister();
182 		exit(0);
183 	}
184 	errno = saved_errno;
185 	return;
186 }
187 
188 static void
189 usage(void)
190 {
191 	fprintf(stderr, "usage: ypserv [-h] [-d] [-n] [-p path]\n");
192 	exit(1);
193 }
194 
195 static void
196 closedown(int sig)
197 {
198 	if (_rpcsvcstate == _IDLE) {
199 		extern fd_set svc_fdset;
200 		static int size;
201 		int i, openfd;
202 
203 		if (_rpcfdtype == SOCK_DGRAM) {
204 			unregister();
205 			exit(0);
206 		}
207 		if (size == 0) {
208 			size = getdtablesize();
209 		}
210 		for (i = 0, openfd = 0; i < size && openfd < 2; i++)
211 			if (FD_ISSET(i, &svc_fdset))
212 				openfd++;
213 		if (openfd <= 1) {
214 			unregister();
215 			exit(0);
216 		}
217 	}
218 	if (_rpcsvcstate == _SERVED)
219 		_rpcsvcstate = _IDLE;
220 
221 	signal(SIGALRM, (SIG_PF)closedown);
222 	alarm(_RPCSVC_CLOSEDOWN / 2);
223 }
224 
225 int
226 main(int argc, char **argv)
227 {
228 	SVCXPRT *transp = NULL;
229 	int sock;
230 	int proto = 0;
231 	struct sockaddr_in saddr;
232 	int asize = sizeof(saddr);
233 	int ch;
234 
235 	while ((ch = getopt(argc, argv, "hdnp:")) != -1) {
236 		switch (ch) {
237 		case 'd':
238 			debug = ypdb_debug = 1;
239 			break;
240 		case 'n':
241 			do_dns = 1;
242 			break;
243 		case 'p':
244 			yp_dir = optarg;
245 			break;
246 		case 'h':
247 		default:
248 			usage();
249 		}
250 	}
251 
252 	load_securenets();
253 	yp_init_resolver();
254 #ifdef DB_CACHE
255 	yp_init_dbs();
256 #endif
257 	if (getsockname(0, (struct sockaddr *)&saddr, &asize) == 0) {
258 		int ssize = sizeof (int);
259 
260 		if (saddr.sin_family != AF_INET)
261 			exit(1);
262 		if (getsockopt(0, SOL_SOCKET, SO_TYPE,
263 				(char *)&_rpcfdtype, &ssize) == -1)
264 			exit(1);
265 		sock = 0;
266 		_rpcpmstart = 1;
267 		proto = 0;
268 		openlog("ypserv", LOG_PID, LOG_DAEMON);
269 	} else {
270 		if (!debug) {
271 			if (daemon(0,0)) {
272 				err(1,"cannot fork");
273 			}
274 			openlog("ypserv", LOG_PID, LOG_DAEMON);
275 		}
276 		sock = RPC_ANYSOCK;
277 		pmap_unset(YPPROG, YPVERS);
278 		pmap_unset(YPPROG, 1);
279 	}
280 
281 	if ((_rpcfdtype == 0) || (_rpcfdtype == SOCK_DGRAM)) {
282 		transp = svcudp_create(sock);
283 		if (transp == NULL) {
284 			_msgout("cannot create udp service");
285 			exit(1);
286 		}
287 		if (!_rpcpmstart)
288 			proto = IPPROTO_UDP;
289 		if (!svc_register(transp, YPPROG, YPOLDVERS, ypprog_1, proto)) {
290 			_msgout("unable to register (YPPROG, YPOLDVERS, udp)");
291 			exit(1);
292 		}
293 		if (!svc_register(transp, YPPROG, YPVERS, ypprog_2, proto)) {
294 			_msgout("unable to register (YPPROG, YPVERS, udp)");
295 			exit(1);
296 		}
297 	}
298 
299 	if ((_rpcfdtype == 0) || (_rpcfdtype == SOCK_STREAM)) {
300 		transp = svctcp_create(sock, 0, 0);
301 		if (transp == NULL) {
302 			_msgout("cannot create tcp service");
303 			exit(1);
304 		}
305 		if (!_rpcpmstart)
306 			proto = IPPROTO_TCP;
307 		if (!svc_register(transp, YPPROG, YPOLDVERS, ypprog_1, proto)) {
308 			_msgout("unable to register (YPPROG, YPOLDVERS, tcp)");
309 			exit(1);
310 		}
311 		if (!svc_register(transp, YPPROG, YPVERS, ypprog_2, proto)) {
312 			_msgout("unable to register (YPPROG, YPVERS, tcp)");
313 			exit(1);
314 		}
315 	}
316 
317 	if (transp == (SVCXPRT *)NULL) {
318 		_msgout("could not create a handle");
319 		exit(1);
320 	}
321 	if (_rpcpmstart) {
322 		signal(SIGALRM, (SIG_PF)closedown);
323 		alarm(_RPCSVC_CLOSEDOWN / 2);
324 	}
325 /*
326  * Make sure SIGPIPE doesn't blow us away while servicing TCP
327  * connections.
328  */
329 	signal(SIGPIPE, SIG_IGN);
330 	signal(SIGCHLD, (SIG_PF) reaper);
331 	signal(SIGTERM, (SIG_PF) reaper);
332 	signal(SIGINT, (SIG_PF) reaper);
333 	signal(SIGHUP, (SIG_PF) reaper);
334 	yp_svc_run();
335 	_msgout("svc_run returned");
336 	exit(1);
337 	/* NOTREACHED */
338 }
339