OpenBSD-4.6/sbin/mount_portal/mount_portal.c
/* $OpenBSD: mount_portal.c,v 1.28 2008/06/01 18:38:29 sobrado Exp $ */
/* $NetBSD: mount_portal.c,v 1.8 1996/04/13 01:31:54 jtc Exp $ */
/*
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1992, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)mount_portal.c 8.6 (Berkeley) 4/26/95";
#else
static char rcsid[] = "$OpenBSD: mount_portal.c,v 1.28 2008/06/01 18:38:29 sobrado Exp $";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/syslog.h>
#include <sys/mount.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "mntopts.h"
#include "pathnames.h"
#include "portald.h"
const struct mntopt mopts[] = {
MOPT_STDOPTS,
{ NULL }
};
extern char *__progname; /* from crt0.o */
static char mountpt[MAXPATHLEN]; /* made available to signal handler */
static void usage(void);
static volatile sig_atomic_t readcf; /* Set when SIGHUP received */
static void
sigchld(int sig)
{
int save_errno = errno;
struct syslog_data sdata = SYSLOG_DATA_INIT;
pid_t pid;
while ((pid = waitpid((pid_t) -1, NULL, WNOHANG)) > 0)
;
if (pid < 0 && errno != ECHILD)
syslog_r(LOG_WARNING, &sdata, "waitpid: %m");
errno = save_errno;
}
static void
sighup(int sig)
{
readcf = 1;
}
static void
sigterm(int sig)
{
struct syslog_data sdata = SYSLOG_DATA_INIT;
if (unmount(mountpt, MNT_FORCE) < 0)
syslog_r(LOG_WARNING, &sdata,
"sigterm: unmounting %s failed: %m", mountpt);
_exit(1);
}
int
main(int argc, char *argv[])
{
struct portal_args args;
struct sockaddr_un un;
char *conf;
int mntflags = 0;
char tag[32];
fd_set *fdsp;
int fdssize;
qelem q;
int so;
int error = 0;
/*
* Crack command line args
*/
int ch;
while ((ch = getopt(argc, argv, "o:")) != -1) {
switch (ch) {
case 'o':
getmntopts(optarg, mopts, &mntflags);
break;
default:
error = 1;
break;
}
}
if (optind != (argc - 2))
error = 1;
if (error)
usage();
/*
* Get config file and mount point
*/
conf = argv[optind];
if (realpath(argv[optind+1], mountpt) == NULL)
err(1, "realpath %s", argv[optind+1]);
/*
* Construct the listening socket
*/
un.sun_family = AF_UNIX;
if (sizeof(_PATH_TMPPORTAL) >= sizeof(un.sun_path))
errx(1, "portal socket name too long");
(void)strlcpy(un.sun_path, _PATH_TMPPORTAL, sizeof un.sun_path);
so = mkstemp(un.sun_path);
if (so < 0)
err(1, "can't create portal socket name: %s", un.sun_path);
un.sun_len = strlen(un.sun_path);
(void)close(so);
so = socket(AF_UNIX, SOCK_STREAM, 0);
if (so < 0)
err(1, "socket(2)");
(void)unlink(un.sun_path);
/* XXX teeny race? */
if (bind(so, (struct sockaddr *) &un, sizeof(un)) < 0)
err(1, "bind(2)");
(void)listen(so, 5);
args.pa_socket = so;
/*
* Must fork before mount to get pid in name right.
*/
daemon(0, 0);
(void)snprintf(tag, sizeof(tag), "portal:%ld", (long)getpid());
args.pa_config = tag;
/*
* Start logging (and change name)
*/
openlog("portald", LOG_CONS|LOG_PID, LOG_DAEMON);
if (mount(MOUNT_PORTAL, mountpt, mntflags, &args)) {
if (errno == EOPNOTSUPP)
syslog(LOG_ERR,
"mount: Filesystem not supported by kernel");
else
syslog(LOG_ERR, "mount: %m");
exit(1);
}
q.q_forw = q.q_back = &q;
readcf = 1;
(void)signal(SIGCHLD, sigchld);
(void)signal(SIGHUP, sighup);
(void)signal(SIGTERM, sigterm);
fdssize = howmany(so+1, NFDBITS) * sizeof(fd_mask);
fdsp = (fd_set *)malloc(fdssize);
if (fdsp == NULL)
err(1, "malloc");
/*
* Just loop waiting for new connections and activating them
*/
for (;;) {
struct sockaddr_un un2;
socklen_t salen = sizeof(un2);
int so2;
pid_t pid;
int rc;
/*
* Check whether we need to re-read the configuration file
*/
if (readcf) {
readcf = 0;
conf_read(&q, conf);
continue;
}
/*
* Accept a new connection
* Will get EINTR if a signal has arrived, so just
* ignore that error code
*/
memset(fdsp, 0, fdssize);
FD_SET(so, fdsp);
rc = select(so+1, fdsp, NULL, NULL, NULL);
if (rc < 0) {
if (errno == EINTR)
continue;
syslog(LOG_ERR, "select: %m");
exit(1);
}
if (rc == 0)
break;
so2 = accept(so, (struct sockaddr *) &un2, &salen);
if (so2 < 0) {
/*
* The unmount function does a shutdown on the socket
* which will generated ECONNABORTED on the accept.
*/
if (errno == ECONNABORTED)
break;
if (errno != EINTR) {
syslog(LOG_ERR, "accept: %m");
exit(1);
}
continue;
}
/*
* Now fork a new child to deal with the connection
*/
eagain:;
switch (pid = fork()) {
case -1:
if (errno == EAGAIN) {
sleep(1);
goto eagain;
}
syslog(LOG_ERR, "fork: %m");
break;
case 0:
(void)close(so);
activate(&q, so2);
exit(0);
default:
(void)close(so2);
break;
}
}
free(fdsp);
syslog(LOG_INFO, "%s unmounted", mountpt);
exit(0);
}
static void
usage(void)
{
(void)fprintf(stderr,
"usage: %s [-o options] config mount_point\n", __progname);
exit(1);
}