Systemd/src/shared/fstab-util.c

287 lines
8.4 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2015 Zbigniew Jędrzejewski-Szmek
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "alloc-util.h"
#include "device-nodes.h"
#include "fstab-util.h"
#include "macro.h"
#include "mount-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
int fstab_has_fstype(const char *fstype) {
_cleanup_endmntent_ FILE *f = NULL;
struct mntent *m;
f = setmntent("/etc/fstab", "re");
if (!f)
return errno == ENOENT ? false : -errno;
for (;;) {
errno = 0;
m = getmntent(f);
if (!m)
return errno != 0 ? -errno : false;
if (streq(m->mnt_type, fstype))
return true;
}
return false;
}
int fstab_is_mount_point(const char *mount) {
_cleanup_endmntent_ FILE *f = NULL;
struct mntent *m;
f = setmntent("/etc/fstab", "re");
if (!f)
return errno == ENOENT ? false : -errno;
for (;;) {
errno = 0;
m = getmntent(f);
if (!m)
return errno != 0 ? -errno : false;
if (path_equal(m->mnt_dir, mount))
return true;
}
return false;
}
int fstab_filter_options(const char *opts, const char *names,
const char **namefound, char **value, char **filtered) {
const char *name, *n = NULL, *x;
_cleanup_strv_free_ char **stor = NULL;
_cleanup_free_ char *v = NULL, **strv = NULL;
assert(names && *names);
if (!opts)
goto answer;
/* If !value and !filtered, this function is not allowed to fail. */
if (!filtered) {
const char *word, *state;
size_t l;
FOREACH_WORD_SEPARATOR(word, l, opts, ",", state)
NULSTR_FOREACH(name, names) {
if (l < strlen(name))
continue;
if (!strneq(word, name, strlen(name)))
continue;
/* we know that the string is NUL
* terminated, so *x is valid */
x = word + strlen(name);
if (IN_SET(*x, '\0', '=', ',')) {
n = name;
if (value) {
free(v);
if (IN_SET(*x, '\0', ','))
v = NULL;
else {
assert(*x == '=');
x++;
v = strndup(x, l - strlen(name) - 1);
if (!v)
return -ENOMEM;
}
}
}
}
} else {
char **t, **s;
stor = strv_split(opts, ",");
if (!stor)
return -ENOMEM;
strv = memdup(stor, sizeof(char*) * (strv_length(stor) + 1));
if (!strv)
return -ENOMEM;
for (s = t = strv; *s; s++) {
NULSTR_FOREACH(name, names) {
x = startswith(*s, name);
if (x && IN_SET(*x, '\0', '='))
goto found;
}
*t = *s;
t++;
continue;
found:
/* Keep the last occurence found */
n = name;
if (value) {
free(v);
if (*x == '\0')
v = NULL;
else {
assert(*x == '=');
x++;
v = strdup(x);
if (!v)
return -ENOMEM;
}
}
}
*t = NULL;
}
answer:
if (namefound)
*namefound = n;
if (filtered) {
char *f;
f = strv_join(strv, ",");
if (!f)
return -ENOMEM;
*filtered = f;
}
if (value)
*value = TAKE_PTR(v);
return !!n;
}
int fstab_extract_values(const char *opts, const char *name, char ***values) {
_cleanup_strv_free_ char **optsv = NULL, **res = NULL;
char **s;
assert(opts);
assert(name);
assert(values);
optsv = strv_split(opts, ",");
if (!optsv)
return -ENOMEM;
STRV_FOREACH(s, optsv) {
char *arg;
int r;
arg = startswith(*s, name);
if (!arg || *arg != '=')
continue;
r = strv_extend(&res, arg + 1);
if (r < 0)
return r;
}
*values = TAKE_PTR(res);
return !!*values;
}
int fstab_find_pri(const char *options, int *ret) {
_cleanup_free_ char *opt = NULL;
int r;
unsigned pri;
assert(ret);
r = fstab_filter_options(options, "pri\0", NULL, &opt, NULL);
if (r < 0)
return r;
if (r == 0 || !opt)
return 0;
r = safe_atou(opt, &pri);
if (r < 0)
return r;
if ((int) pri < 0)
return -ERANGE;
*ret = (int) pri;
return 1;
}
static char *unquote(const char *s, const char* quotes) {
size_t l;
assert(s);
/* This is rather stupid, simply removes the heading and
* trailing quotes if there is one. Doesn't care about
* escaping or anything.
*
* DON'T USE THIS FOR NEW CODE ANYMORE! */
l = strlen(s);
if (l < 2)
return strdup(s);
if (strchr(quotes, s[0]) && s[l-1] == s[0])
return strndup(s+1, l-2);
return strdup(s);
}
static char *tag_to_udev_node(const char *tagvalue, const char *by) {
_cleanup_free_ char *t = NULL, *u = NULL;
size_t enc_len;
u = unquote(tagvalue, QUOTES);
if (!u)
return NULL;
enc_len = strlen(u) * 4 + 1;
t = new(char, enc_len);
if (!t)
return NULL;
if (encode_devnode_name(u, t, enc_len) < 0)
return NULL;
return strjoin("/dev/disk/by-", by, "/", t);
}
char *fstab_node_to_udev_node(const char *p) {
assert(p);
if (startswith(p, "LABEL="))
return tag_to_udev_node(p+6, "label");
if (startswith(p, "UUID="))
return tag_to_udev_node(p+5, "uuid");
if (startswith(p, "PARTUUID="))
return tag_to_udev_node(p+9, "partuuid");
if (startswith(p, "PARTLABEL="))
return tag_to_udev_node(p+10, "partlabel");
return strdup(p);
}