[thirdparty/systemd.git] / src / shared / fstab-util.c

/* SPDX-License-Identifier: LGPL-2.1+ */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "alloc-util.h"
#include "device-nodes.h"
#include "fstab-util.h"
#include "macro.h"
#include "mount-util.h"
#include "nulstr-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "string-util.h"
#include "strv.h"

int fstab_has_fstype(const char *fstype) {
        _cleanup_endmntent_ FILE *f = NULL;
        struct mntent *m;

        f = setmntent(fstab_path(), "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;
}

bool fstab_is_extrinsic(const char *mount, const char *opts) {

        /* Don't bother with the OS data itself */
        if (PATH_IN_SET(mount,
                        "/",
                        "/usr",
                        "/etc"))
                return true;

        if (PATH_STARTSWITH_SET(mount,
                                "/run/initramfs",    /* This should stay around from before we boot until after we shutdown */
                                "/proc",             /* All of this is API VFS */
                                "/sys",              /* … dito … */
                                "/dev"))             /* … dito … */
                return true;

        /* If this is an initrd mount, and we are not in the initrd, then leave
         * this around forever, too. */
        if (opts && fstab_test_option(opts, "x-initrd.mount\0") && !in_initrd())
                return true;

        return false;
}

int fstab_is_mount_point(const char *mount) {
        _cleanup_endmntent_ FILE *f = NULL;
        struct mntent *m;

        f = setmntent(fstab_path(), "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 **ret_namefound, char **ret_value, char **ret_filtered) {
        const char *name, *namefound = NULL, *x;
        _cleanup_strv_free_ char **stor = NULL;
        _cleanup_free_ char *v = NULL, **strv = NULL;
        int r;

        assert(names && *names);

        if (!opts)
                goto answer;

        /* If !ret_value and !ret_filtered, this function is not allowed to fail. */

        if (!ret_filtered) {
                for (const char *word = opts;;) {
                        const char *end = word;

                        /* Look for an *non-escaped* comma separator. Only commas can be escaped, so "\," is
                         * the only valid escape sequence, so we can do a very simple test here. */
                        for (;;) {
                                size_t n = strcspn(end, ",");

                                end += n;
                                if (n > 0 && end[-1] == '\\')
                                        end++;
                                else
                                        break;
                        }

                        NULSTR_FOREACH(name, names) {
                                if (end < word + 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', '=', ',')) {
                                        namefound = name;
                                        if (ret_value) {
                                                bool eq = *x == '=';
                                                assert(eq || IN_SET(*x, ',', '\0'));

                                                r = free_and_strndup(&v,
                                                                     eq ? x + 1 : NULL,
                                                                     eq ? end - x - 1 : 0);
                                                if (r < 0)
                                                        return r;
                                        }

                                        break;
                                }
                        }

                        if (*end)
                                word = end + 1;
                        else
                                break;
                }
        } else {
                r = strv_split_full(&stor, opts, ",", EXTRACT_DONT_COALESCE_SEPARATORS | EXTRACT_UNESCAPE_SEPARATORS);
                if (r < 0)
                        return r;

                strv = memdup(stor, sizeof(char*) * (strv_length(stor) + 1));
                if (!strv)
                        return -ENOMEM;

                char **t = strv;
                for (char **s = 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 occurrence found */
                        namefound = name;
                        if (ret_value) {
                                assert(IN_SET(*x, '=', '\0'));
                                r = free_and_strdup(&v, *x == '=' ? x + 1 : NULL);
                                if (r < 0)
                                        return r;
                        }
                }
                *t = NULL;
        }

answer:
        if (ret_namefound)
                *ret_namefound = namefound;
        if (ret_filtered) {
                char *f;

                f = strv_join_full(strv, ",", NULL, true);
                if (!f)
                        return -ENOMEM;

                *ret_filtered = f;
        }
        if (ret_value)
                *ret_value = TAKE_PTR(v);

        return !!namefound;
}

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, 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_atoi(opt, &pri);
        if (r < 0)
                return r;

        *ret = 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);
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
d15d0333	2
a8fbdf54	3	#include <errno.h>
a8fbdf54 TA	4	#include <stdio.h>
a8fbdf54 TA	5	#include <stdlib.h>
a8fbdf54	6
b5efdb8a	7	#include "alloc-util.h"
6550203e	8	#include "device-nodes.h"
6bedfcbb	9	#include "fstab-util.h"
a8fbdf54	10	#include "macro.h"
4349cd7c	11	#include "mount-util.h"
d8b4d14d	12	#include "nulstr-util.h"
6bedfcbb	13	#include "parse-util.h"
0b6b6787	14	#include "path-util.h"
07630cea	15	#include "string-util.h"
d15d0333	16	#include "strv.h"
d15d0333	17
6c1921e9 FB	18	int fstab_has_fstype(const char *fstype) {
	19	_cleanup_endmntent_ FILE *f = NULL;
	20	struct mntent *m;
	21
ed4ad488	22	f = setmntent(fstab_path(), "re");
6c1921e9 FB	23	if (!f)
	24	return errno == ENOENT ? false : -errno;
	25
	26	for (;;) {
	27	errno = 0;
	28	m = getmntent(f);
	29	if (!m)
	30	return errno != 0 ? -errno : false;
	31
	32	if (streq(m->mnt_type, fstype))
	33	return true;
	34	}
	35	return false;
	36	}
	37
bc9e5a4c FB	38	bool fstab_is_extrinsic(const char mount, const char opts) {
	39
	40	/* Don't bother with the OS data itself */
	41	if (PATH_IN_SET(mount,
	42	"/",
	43	"/usr",
	44	"/etc"))
	45	return true;
	46
	47	if (PATH_STARTSWITH_SET(mount,
	48	"/run/initramfs", /* This should stay around from before we boot until after we shutdown */
	49	"/proc", /* All of this is API VFS */
	50	"/sys", /* … dito … */
	51	"/dev")) /* … dito … */
	52	return true;
	53
	54	/* If this is an initrd mount, and we are not in the initrd, then leave
	55	* this around forever, too. */
	56	if (opts && fstab_test_option(opts, "x-initrd.mount\0") && !in_initrd())
	57	return true;
	58
	59	return false;
	60	}
	61
b9088048	62	int fstab_is_mount_point(const char *mount) {
0b6b6787 KS	63	_cleanup_endmntent_ FILE *f = NULL;
	64	struct mntent *m;
	65
ed4ad488	66	f = setmntent(fstab_path(), "re");
0b6b6787	67	if (!f)
b9088048 FB	68	return errno == ENOENT ? false : -errno;
	69
	70	for (;;) {
	71	errno = 0;
	72	m = getmntent(f);
	73	if (!m)
	74	return errno != 0 ? -errno : false;
0b6b6787	75
0b6b6787 KS	76	if (path_equal(m->mnt_dir, mount))
0b6b6787 KS	77	return true;
b9088048	78	}
0b6b6787 KS	79	return false;
	80	}
	81
d15d0333	82	int fstab_filter_options(const char opts, const char names,
92a08691	83	const char ret_namefound, char ret_value, char **ret_filtered) {
0e8d1859	84	const char name, namefound = NULL, *x;
d15d0333 ZJS	85	_cleanup_strv_free_ char **stor = NULL;
d15d0333 ZJS	86	_cleanup_free_ char v = NULL, *strv = NULL;
0e8d1859	87	int r;
d15d0333 ZJS	88
	89	assert(names && *names);
	90
	91	if (!opts)
	92	goto answer;
	93
0e8d1859	94	/* If !ret_value and !ret_filtered, this function is not allowed to fail. */
d15d0333	95
92a08691	96	if (!ret_filtered) {
45638a63	97	for (const char *word = opts;;) {
7bb553bb ZJS	98	const char *end = word;
	99
	100	/* Look for an non-escaped comma separator. Only commas can be escaped, so "\," is
	101	* the only valid escape sequence, so we can do a very simple test here. */
	102	for (;;) {
	103	size_t n = strcspn(end, ",");
	104
	105	end += n;
	106	if (n > 0 && end[-1] == '\\')
	107	end++;
	108	else
	109	break;
	110	}
d15d0333	111
d15d0333	112	NULSTR_FOREACH(name, names) {
45638a63	113	if (end < word + strlen(name))
d15d0333 ZJS	114	continue;
	115	if (!strneq(word, name, strlen(name)))
	116	continue;
	117
0e8d1859	118	/* We know that the string is NUL terminated, so x is valid /
d15d0333 ZJS	119	x = word + strlen(name);
d15d0333 ZJS	120	if (IN_SET(*x, '\0', '=', ',')) {
0e8d1859	121	namefound = name;
92a08691	122	if (ret_value) {
0e8d1859 ZJS	123	bool eq = *x == '=';
	124	assert(eq \|\| IN_SET(*x, ',', '\0'));
	125
	126	r = free_and_strndup(&v,
	127	eq ? x + 1 : NULL,
45638a63	128	eq ? end - x - 1 : 0);
0e8d1859 ZJS	129	if (r < 0)
0e8d1859 ZJS	130	return r;
d15d0333	131	}
45638a63 ZJS	132
45638a63 ZJS	133	break;
d15d0333 ZJS	134	}
d15d0333 ZJS	135	}
45638a63 ZJS	136
	137	if (*end)
	138	word = end + 1;
	139	else
	140	break;
	141	}
d15d0333	142	} else {
7bb553bb ZJS	143	r = strv_split_full(&stor, opts, ",", EXTRACT_DONT_COALESCE_SEPARATORS \| EXTRACT_UNESCAPE_SEPARATORS);
	144	if (r < 0)
	145	return r;
	146
d15d0333 ZJS	147	strv = memdup(stor, sizeof(char) (strv_length(stor) + 1));
	148	if (!strv)
	149	return -ENOMEM;
	150
0e8d1859 ZJS	151	char **t = strv;
0e8d1859 ZJS	152	for (char *s = strv; s; s++) {
d15d0333 ZJS	153	NULSTR_FOREACH(name, names) {
	154	x = startswith(*s, name);
	155	if (x && IN_SET(*x, '\0', '='))
	156	goto found;
	157	}
	158
	159	t = s;
	160	t++;
	161	continue;
	162	found:
5238e957	163	/* Keep the last occurrence found */
0e8d1859	164	namefound = name;
92a08691	165	if (ret_value) {
0e8d1859 ZJS	166	assert(IN_SET(*x, '=', '\0'));
	167	r = free_and_strdup(&v, *x == '=' ? x + 1 : NULL);
	168	if (r < 0)
	169	return r;
d15d0333 ZJS	170	}
	171	}
	172	*t = NULL;
	173	}
	174
	175	answer:
92a08691	176	if (ret_namefound)
0e8d1859	177	*ret_namefound = namefound;
92a08691	178	if (ret_filtered) {
d15d0333 ZJS	179	char *f;
d15d0333 ZJS	180
7bb553bb	181	f = strv_join_full(strv, ",", NULL, true);
d15d0333 ZJS	182	if (!f)
	183	return -ENOMEM;
	184
92a08691	185	*ret_filtered = f;
d15d0333	186	}
92a08691 LP	187	if (ret_value)
92a08691 LP	188	*ret_value = TAKE_PTR(v);
d15d0333	189
0e8d1859	190	return !!namefound;
d15d0333 ZJS	191	}
d15d0333 ZJS	192
3519d230 KZ	193	int fstab_extract_values(const char opts, const char name, char ***values) {
	194	_cleanup_strv_free_ char optsv = NULL, res = NULL;
	195	char **s;
	196
	197	assert(opts);
	198	assert(name);
	199	assert(values);
	200
	201	optsv = strv_split(opts, ",");
	202	if (!optsv)
	203	return -ENOMEM;
	204
	205	STRV_FOREACH(s, optsv) {
	206	char *arg;
	207	int r;
	208
	209	arg = startswith(*s, name);
	210	if (!arg \|\| *arg != '=')
	211	continue;
	212	r = strv_extend(&res, arg + 1);
	213	if (r < 0)
	214	return r;
	215	}
	216
ae2a15bc	217	*values = TAKE_PTR(res);
3519d230 KZ	218
	219	return !!*values;
	220	}
	221
d15d0333 ZJS	222	int fstab_find_pri(const char options, int ret) {
d15d0333 ZJS	223	_cleanup_free_ char *opt = NULL;
7477451b	224	int r, pri;
d15d0333 ZJS	225
	226	assert(ret);
	227
	228	r = fstab_filter_options(options, "pri\0", NULL, &opt, NULL);
a75f4e2a	229	if (r < 0)
d15d0333	230	return r;
a75f4e2a ZJS	231	if (r == 0 \|\| !opt)
a75f4e2a ZJS	232	return 0;
d15d0333	233
7477451b	234	r = safe_atoi(opt, &pri);
d15d0333 ZJS	235	if (r < 0)
	236	return r;
	237
7477451b	238	*ret = pri;
d15d0333 ZJS	239	return 1;
d15d0333 ZJS	240	}
6550203e LP	241
	242	static char unquote(const char s, const char* quotes) {
	243	size_t l;
	244	assert(s);
	245
	246	/* This is rather stupid, simply removes the heading and
	247	* trailing quotes if there is one. Doesn't care about
	248	* escaping or anything.
	249	*
13e785f7	250	* DON'T USE THIS FOR NEW CODE ANYMORE! */
6550203e LP	251
	252	l = strlen(s);
	253	if (l < 2)
	254	return strdup(s);
	255
	256	if (strchr(quotes, s[0]) && s[l-1] == s[0])
	257	return strndup(s+1, l-2);
	258
	259	return strdup(s);
	260	}
	261
	262	static char tag_to_udev_node(const char tagvalue, const char *by) {
	263	_cleanup_free_ char t = NULL, u = NULL;
	264	size_t enc_len;
	265
	266	u = unquote(tagvalue, QUOTES);
	267	if (!u)
	268	return NULL;
	269
	270	enc_len = strlen(u) * 4 + 1;
	271	t = new(char, enc_len);
	272	if (!t)
	273	return NULL;
	274
	275	if (encode_devnode_name(u, t, enc_len) < 0)
	276	return NULL;
	277
605405c6	278	return strjoin("/dev/disk/by-", by, "/", t);
6550203e LP	279	}
	280
	281	char fstab_node_to_udev_node(const char p) {
	282	assert(p);
	283
	284	if (startswith(p, "LABEL="))
	285	return tag_to_udev_node(p+6, "label");
	286
	287	if (startswith(p, "UUID="))
	288	return tag_to_udev_node(p+5, "uuid");
	289
	290	if (startswith(p, "PARTUUID="))
	291	return tag_to_udev_node(p+9, "partuuid");
	292
	293	if (startswith(p, "PARTLABEL="))
	294	return tag_to_udev_node(p+10, "partlabel");
	295
	296	return strdup(p);
	297	}