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/*-
* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <libutil.h>
#include <assert.h>
#include <pathnames.h> /* _PATH_MOUNTDPID */
#include <fsshare.h>
#define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n"
#define OPTSSIZE 1024
#define MAXLINESIZE (PATH_MAX + OPTSSIZE)
static void
restart_mountd(void)
{
struct pidfh *pfh;
pid_t mountdpid;
pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
if (pfh != NULL) {
/* Mountd is not running. */
pidfile_remove(pfh);
return;
}
if (errno != EEXIST) {
/* Cannot open pidfile for some reason. */
return;
}
/* We have mountd(8) PID in mountdpid varible. */
kill(mountdpid, SIGHUP);
}
/*
* Read one line from a file. Skip comments, empty lines and a line with a
* mountpoint specified in the 'skip' argument.
*/
static char *
getline(FILE *fd, const char *skip)
{
static char line[MAXLINESIZE];
size_t len, skiplen;
char *s, last;
if (skip != NULL)
skiplen = strlen(skip);
for (;;) {
s = fgets(line, sizeof(line), fd);
if (s == NULL)
return (NULL);
/* Skip empty lines and comments. */
if (line[0] == '\n' || line[0] == '#')
continue;
len = strlen(line);
if (line[len - 1] == '\n')
line[len - 1] = '\0';
last = line[skiplen];
/* Skip the given mountpoint. */
if (skip != NULL && strncmp(skip, line, skiplen) == 0 &&
(last == '\t' || last == ' ' || last == '\0')) {
continue;
}
break;
}
return (line);
}
/*
* Function translate options to a format acceptable by exports(5), eg.
*
* -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org 69.147.83.54
*
* Accepted input formats:
*
* ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,freefall.freebsd.org
* ro network=192.168.0.0 mask=255.255.255.0 maproot=0 freefall.freebsd.org
* -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,freefall.freebsd.org
* -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org
*
* Recognized keywords:
*
* ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs, index, quiet
*
*/
static const char *known_opts[] = { "ro", "maproot", "mapall", "mask",
"network", "sec", "alldirs", "public", "webnfs", "index", "quiet", NULL };
static char *
translate_opts(const char *shareopts)
{
static char newopts[OPTSSIZE];
char oldopts[OPTSSIZE];
char *o, *s = NULL;
unsigned int i;
size_t len;
strlcpy(oldopts, shareopts, sizeof(oldopts));
newopts[0] = '\0';
s = oldopts;
while ((o = strsep(&s, "-, ")) != NULL) {
if (o[0] == '\0')
continue;
for (i = 0; known_opts[i] != NULL; i++) {
len = strlen(known_opts[i]);
if (strncmp(known_opts[i], o, len) == 0 &&
(o[len] == '\0' || o[len] == '=')) {
strlcat(newopts, "-", sizeof(newopts));
break;
}
}
strlcat(newopts, o, sizeof(newopts));
strlcat(newopts, " ", sizeof(newopts));
}
return (newopts);
}
static int
fsshare_main(const char *file, const char *mountpoint, const char *shareopts,
int share)
{
char tmpfile[PATH_MAX];
char *line;
FILE *newfd, *oldfd;
int fd, error;
newfd = oldfd = NULL;
error = 0;
/*
* Create temporary file in the same directory, so we can atomically
* rename it.
*/
if (strlcpy(tmpfile, file, sizeof(tmpfile)) >= sizeof(tmpfile))
return (ENAMETOOLONG);
if (strlcat(tmpfile, ".XXXXXXXX", sizeof(tmpfile)) >= sizeof(tmpfile))
return (ENAMETOOLONG);
fd = mkstemp(tmpfile);
if (fd == -1)
return (errno);
/*
* File name is random, so we don't really need file lock now, but it
* will be needed after rename(2).
*/
error = flock(fd, LOCK_EX);
assert(error == 0 || (error == -1 && errno == EOPNOTSUPP));
newfd = fdopen(fd, "r+");
assert(newfd != NULL);
/* Open old exports file. */
oldfd = fopen(file, "r");
if (oldfd == NULL) {
if (share) {
if (errno != ENOENT) {
error = errno;
goto out;
}
} else {
/* If there is no exports file, ignore the error. */
if (errno == ENOENT)
errno = 0;
error = errno;
goto out;
}
} else {
error = flock(fileno(oldfd), LOCK_EX);
assert(error == 0 || (error == -1 && errno == EOPNOTSUPP));
error = 0;
}
/* Place big, fat warning at the begining of the file. */
fprintf(newfd, "%s", FILE_HEADER);
while (oldfd != NULL && (line = getline(oldfd, mountpoint)) != NULL)
fprintf(newfd, "%s\n", line);
if (oldfd != NULL && ferror(oldfd) != 0) {
error = ferror(oldfd);
goto out;
}
if (ferror(newfd) != 0) {
error = ferror(newfd);
goto out;
}
if (share) {
fprintf(newfd, "%s\t%s\n", mountpoint,
translate_opts(shareopts));
}
out:
if (error != 0)
unlink(tmpfile);
else {
if (rename(tmpfile, file) == -1) {
error = errno;
unlink(tmpfile);
} else {
/*
* Send SIGHUP to mountd, but unlock exports file later.
*/
restart_mountd();
}
}
if (oldfd != NULL) {
flock(fileno(oldfd), LOCK_UN);
fclose(oldfd);
}
if (newfd != NULL) {
flock(fileno(newfd), LOCK_UN);
fclose(newfd);
}
return (error);
}
/*
* Add the given mountpoint to the given exports file.
*/
int
fsshare(const char *file, const char *mountpoint, const char *shareopts)
{
return (fsshare_main(file, mountpoint, shareopts, 1));
}
/*
* Remove the given mountpoint from the given exports file.
*/
int
fsunshare(const char *file, const char *mountpoint)
{
return (fsshare_main(file, mountpoint, NULL, 0));
}
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