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/*
* Copyright (C) 2005-2009 Junjiro Okajima
*
* This program, aufs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* The main purpose of this script is updating /etc/mtab and calling auplilnk.
* This behaviour is highly depending on mount(8) in util-linux package.
*/
#define _XOPEN_SOURCE 500 /* getsubopt */
#define _BSD_SOURCE /* dirfd */
#include <sys/types.h>
#include <dirent.h>
#include <mntent.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wait.h>
#include <linux/aufs_type.h>
#include "au_util.h"
enum { Remount, Bind, Fake, Update, Verbose, AuFlush, LastOpt };
static void test_opts(char opts[], unsigned char flags[])
{
int c;
char *p, *o, *val, *pat[] = {
[Remount] = "remount",
[Bind] = "bind",
NULL
};
o = strdup(opts);
if (!o)
AuFin("stdup");
p = o;
while (*p) {
c = getsubopt(&p, pat, &val);
switch (c) {
case Remount:
flags[Remount] = 1;
break;
case Bind:
flags[Bind] = 1;
break;
}
}
free(o);
}
static int test_flush(char opts[])
{
int err, i;
regex_t preg;
char *p, *o;
const char *pat = "^((add|ins|append|prepend|del)[:=]"
"|(mod|imod)[:=][^,]*=ro"
"|(noplink|ro)$)";
o = strdup(opts);
if (!o)
AuFin("stdup");
p = o;
i = 1;
while ((p = strchr(p, ','))) {
i++;
*p++ = 0;
}
/* todo: try getsubopt(3)? */
err = regcomp(&preg, pat, REG_EXTENDED | REG_NOSUB);
if (err)
AuFin("regcomp");
p = o;
while (i--) {
if (!regexec(&preg, p, 0, NULL, 0)) {
err = 1;
break;
} else
p += strlen(p) + 1;
}
regfree(&preg);
free(o);
return err;
}
static void do_mount(char *dev, char *mntpnt, int argc, char *argv[],
unsigned char flags[])
{
int i;
const int ac = argc + 6;
char *av[ac], **a;
/* todo: eliminate the duplicated options */
a = av;
*a++ = "mount";
*a++ = "-i";
if (flags[Fake])
*a++ = "-f";
if (!flags[Bind] || !flags[Update])
*a++ = "-n";
if (flags[Bind] && flags[Verbose])
*a++ = "-v";
*a++ = "-t";
*a++ = AUFS_NAME;
for (i = 3; i < argc; i++)
if (strcmp(argv[i], "-v") && strcmp(argv[i], "-n"))
*a++ = argv[i];
*a++ = dev;
*a++ = mntpnt;
*a++ = NULL;
#ifdef DEBUG
for (i = 0; av[i] && i < ac; i++)
puts(av[i]);
exit(0);
#endif
execvp("mount", av);
AuFin("mount");
}
/* ---------------------------------------------------------------------- */
int main(int argc, char *argv[])
{
int err, c, status;
pid_t pid;
unsigned char flags[LastOpt];
struct mntent ent;
char *dev, *mntpnt, *opts, *cwd;
DIR *cur;
if (argc < 3) {
errno = EINVAL;
AuFin(NULL);
}
memset(flags, 0, sizeof(flags));
flags[Update] = 1;
opts = NULL;
/* mount(8) always passes the arguments in this order */
dev = argv[1];
mntpnt = argv[2];
while ((c = getopt(argc - 2, argv + 2, "fnvo:")) != -1) {
switch (c) {
case 'f':
flags[Fake] = 1;
break;
case 'n':
flags[Update] = 0;
break;
case 'v':
flags[Verbose] = 1;
break;
case 'o':
opts = optarg;
break;
case '?':
case ':':
errno = EINVAL;
AuFin("internal error");
}
}
cur = opendir(".");
if (!cur)
AuFin(".");
err = chdir(mntpnt);
if (err)
AuFin("%s", mntpnt);
cwd = getcwd(NULL, 0); /* glibc */
if (!cwd)
AuFin("getcwd");
err = fchdir(dirfd(cur));
if (err)
AuFin("fchdir");
closedir(cur); /* ignore */
if (opts)
test_opts(opts, flags);
if (!flags[Bind] && flags[Update]) {
err = access(MTab, R_OK | W_OK);
if (err)
AuFin(MTab);
}
if (flags[Remount]) {
errno = EINVAL;
if (flags[Bind])
AuFin("both of remount and bind are specified");
flags[AuFlush] = test_flush(opts);
if (flags[AuFlush] /* && !flags[Fake] */) {
err = au_plink(cwd, AuPlink_FLUSH, 1, 1);
if (err)
AuFin(NULL);
}
}
pid = fork();
if (!pid) {
/* actual mount operation */
do_mount(dev, mntpnt, argc, argv, flags);
return 0;
} else if (pid < 0)
AuFin("fork");
err = waitpid(pid, &status, 0);
if (err < 0)
AuFin("child process");
err = !WIFEXITED(status);
if (!err)
err = WEXITSTATUS(status);
if (!err && !flags[Bind]) {
if (flags[Update])
err = au_update_mtab(cwd, flags[Remount],
flags[Verbose]);
else if (flags[Verbose]) {
/* withoug blocking plink */
err = au_proc_getmntent(cwd, &ent);
if (!err)
au_print_ent(&ent);
else
AuFin("internal error");
}
}
return err;
}
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