1/*
2 * Copyright (c) 1992, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software donated to Berkeley by
6 * Jan-Simon Pendry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its 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 THE REGENTS 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 THE REGENTS 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
33#ifndef lint
34char copyright[] =
35"@(#) Copyright (c) 1992, 1993, 1994\n\
36	The Regents of the University of California.  All rights reserved.\n";
37#endif /* not lint */
38
39#if 0
40static char sccsid[] = "@(#)mount_portal.c	8.6 (Berkeley) 4/26/95";
41#endif
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD$");
45
46#include <sys/param.h>
47#include <sys/wait.h>
48#include <sys/socket.h>
49#include <sys/un.h>
50#include <sys/stat.h>
51#include <sys/syslog.h>
52#include <sys/mount.h>
53
54#include <err.h>
55#include <errno.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <sysexits.h>
60#include <unistd.h>
61
62#include "mntopts.h"
63#include "pathnames.h"
64#include "portald.h"
65
66struct mntopt mopts[] = {
67	MOPT_STDOPTS,
68	MOPT_END
69};
70
71static void usage(void) __dead2;
72
73static volatile sig_atomic_t readcf;	/* Set when SIGHUP received */
74
75static void sighup(int sig __unused)
76{
77	readcf ++;
78}
79
80static void sigchld(int sig __unused)
81{
82	pid_t pid;
83
84	while ((pid = waitpid((pid_t) -1, (int *) 0, WNOHANG)) > 0)
85		;
86	/* wrtp - waitpid _doesn't_ return 0 when no children! */
87#ifdef notdef
88	if (pid < 0 && errno != ECHILD)
89		syslog(LOG_WARNING, "waitpid: %s", strerror(errno));
90#endif
91}
92
93int
94main(int argc, char *argv[])
95{
96	struct portal_args args;
97	struct sockaddr_un un;
98	char *conf;
99	char mountpt[MAXPATHLEN];
100	int mntflags = 0;
101	char tag[32];
102	mode_t um;
103
104	qelem q;
105	int rc;
106	int so;
107	int error = 0;
108
109	/*
110	 * Crack command line args
111	 */
112	int ch;
113
114	while ((ch = getopt(argc, argv, "o:")) != -1) {
115		switch (ch) {
116		case 'o':
117			getmntopts(optarg, mopts, &mntflags, 0);
118			break;
119		default:
120			error = 1;
121			break;
122		}
123	}
124
125	if (optind != (argc - 2))
126		error = 1;
127
128	if (error)
129		usage();
130
131	/*
132	 * Get config file and mount point
133	 */
134	conf = argv[optind];
135	if (conf[0] != '/') {
136		(void)fprintf(stderr,
137		    "The configuration file must be specified"
138		    "through an absolute file path.\n");
139		exit(EX_USAGE);
140	}
141
142	/* resolve the mountpoint with realpath(3) */
143	(void)checkpath(argv[optind+1], mountpt);
144
145	/*
146	 * Construct the listening socket
147	 */
148	un.sun_family = AF_UNIX;
149	if (sizeof(_PATH_TMPPORTAL) >= sizeof(un.sun_path)) {
150		errx(EX_SOFTWARE, "portal socket name too long");
151	}
152	strcpy(un.sun_path, _PATH_TMPPORTAL);
153	mktemp(un.sun_path);
154	un.sun_len = strlen(un.sun_path);
155
156	so = socket(AF_UNIX, SOCK_STREAM, 0);
157	if (so < 0) {
158		err(EX_OSERR, "socket");
159	}
160	um = umask(077);
161	(void) unlink(un.sun_path);
162	if (bind(so, (struct sockaddr *) &un, sizeof(un)) < 0)
163		err(1, NULL);
164
165	(void) unlink(un.sun_path);
166	(void) umask(um);
167
168	(void) listen(so, 5);
169
170	args.pa_socket = so;
171	sprintf(tag, "portal:%d", getpid());
172	args.pa_config = tag;
173
174	rc = mount("portalfs", mountpt, mntflags, &args);
175	if (rc < 0)
176		err(1, NULL);
177
178	/*
179	 * Everything is ready to go - now is a good time to fork
180	 */
181#ifndef DEBUG
182	daemon(0, 0);
183#endif
184
185	/*
186	 * Start logging (and change name)
187	 */
188	openlog("portald", LOG_CONS|LOG_PID, LOG_DAEMON);
189
190	q.q_forw = q.q_back = &q;
191	readcf = 1;
192
193	signal(SIGCHLD, sigchld);
194	signal(SIGHUP, sighup);
195
196	/*
197	 * Just loop waiting for new connections and activating them
198	 */
199	for (;;) {
200		struct sockaddr_un un2;
201		int len2 = sizeof(un2);
202		int so2;
203		pid_t pid;
204		fd_set fdset;
205
206		/*
207		 * Check whether we need to re-read the configuration file
208		 */
209		if (readcf) {
210#ifdef DEBUG
211			printf ("re-reading configuration file\n");
212#endif
213			readcf = 0;
214			conf_read(&q, conf);
215			continue;
216		}
217
218		/*
219		 * Accept a new connection
220		 * Will get EINTR if a signal has arrived, so just
221		 * ignore that error code
222		 */
223		FD_ZERO(&fdset);
224		FD_SET(so, &fdset);
225		rc = select(so+1, &fdset, (fd_set *) 0, (fd_set *) 0, (struct timeval *) 0);
226		if (rc < 0) {
227			if (errno == EINTR)
228				continue;
229			syslog(LOG_ERR, "select: %s", strerror(errno));
230			exit(EX_OSERR);
231		}
232		if (rc == 0)
233			break;
234		so2 = accept(so, (struct sockaddr *) &un2, &len2);
235		if (so2 < 0) {
236			/*
237			 * The unmount function does a shutdown on the socket
238			 * which will generated ECONNABORTED on the accept.
239			 */
240			if (errno == ECONNABORTED)
241				break;
242			if (errno != EINTR) {
243				syslog(LOG_ERR, "accept: %s", strerror(errno));
244				exit(EX_OSERR);
245			}
246			continue;
247		}
248
249		/*
250		 * Now fork a new child to deal with the connection
251		 */
252	eagain:;
253		switch (pid = fork()) {
254		case -1:
255			if (errno == EAGAIN) {
256				sleep(1);
257				goto eagain;
258			}
259			syslog(LOG_ERR, "fork: %s", strerror(errno));
260			break;
261		case 0:
262			(void) close(so);
263			activate(&q, so2);
264			exit(0);
265		default:
266			(void) close(so2);
267			break;
268		}
269	}
270	syslog(LOG_INFO, "%s unmounted", mountpt);
271	exit(0);
272}
273
274static void
275usage(void)
276{
277	(void)fprintf(stderr,
278		"usage: mount_portalfs [-o options] config mount-point\n");
279	exit(EX_USAGE);
280}
281