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

/* SPDX-License-Identifier: LGPL-2.1+ */
/***
  Copyright © 2015 Zbigniew Jędrzejewski-Szmek
***/

#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);
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
d15d0333	2	/***
96b2fb93	3	Copyright © 2015 Zbigniew Jędrzejewski-Szmek
d15d0333 ZJS	4	***/
d15d0333 ZJS	5
a8fbdf54 TA	6	#include <errno.h>
	7	#include <mntent.h>
	8	#include <stdio.h>
	9	#include <stdlib.h>
	10	#include <string.h>
	11
b5efdb8a	12	#include "alloc-util.h"
6550203e	13	#include "device-nodes.h"
6bedfcbb	14	#include "fstab-util.h"
a8fbdf54	15	#include "macro.h"
4349cd7c	16	#include "mount-util.h"
6bedfcbb	17	#include "parse-util.h"
0b6b6787	18	#include "path-util.h"
07630cea	19	#include "string-util.h"
d15d0333 ZJS	20	#include "strv.h"
	21	#include "util.h"
	22
6c1921e9 FB	23	int fstab_has_fstype(const char *fstype) {
	24	_cleanup_endmntent_ FILE *f = NULL;
	25	struct mntent *m;
	26
	27	f = setmntent("/etc/fstab", "re");
	28	if (!f)
	29	return errno == ENOENT ? false : -errno;
	30
	31	for (;;) {
	32	errno = 0;
	33	m = getmntent(f);
	34	if (!m)
	35	return errno != 0 ? -errno : false;
	36
	37	if (streq(m->mnt_type, fstype))
	38	return true;
	39	}
	40	return false;
	41	}
	42
b9088048	43	int fstab_is_mount_point(const char *mount) {
0b6b6787 KS	44	_cleanup_endmntent_ FILE *f = NULL;
	45	struct mntent *m;
	46
9ffcff0e	47	f = setmntent("/etc/fstab", "re");
0b6b6787	48	if (!f)
b9088048 FB	49	return errno == ENOENT ? false : -errno;
	50
	51	for (;;) {
	52	errno = 0;
	53	m = getmntent(f);
	54	if (!m)
	55	return errno != 0 ? -errno : false;
0b6b6787	56
0b6b6787 KS	57	if (path_equal(m->mnt_dir, mount))
0b6b6787 KS	58	return true;
b9088048	59	}
0b6b6787 KS	60	return false;
	61	}
	62
d15d0333 ZJS	63	int fstab_filter_options(const char opts, const char names,
	64	const char namefound, char value, char **filtered) {
	65	const char name, n = NULL, *x;
	66	_cleanup_strv_free_ char **stor = NULL;
	67	_cleanup_free_ char v = NULL, *strv = NULL;
	68
	69	assert(names && *names);
	70
	71	if (!opts)
	72	goto answer;
	73
	74	/* If !value and !filtered, this function is not allowed to fail. */
	75
	76	if (!filtered) {
	77	const char word, state;
	78	size_t l;
	79
	80	FOREACH_WORD_SEPARATOR(word, l, opts, ",", state)
	81	NULSTR_FOREACH(name, names) {
	82	if (l < strlen(name))
	83	continue;
	84	if (!strneq(word, name, strlen(name)))
	85	continue;
	86
	87	/* we know that the string is NUL
	88	* terminated, so x is valid /
	89	x = word + strlen(name);
	90	if (IN_SET(*x, '\0', '=', ',')) {
	91	n = name;
	92	if (value) {
	93	free(v);
	94	if (IN_SET(*x, '\0', ','))
	95	v = NULL;
	96	else {
	97	assert(*x == '=');
	98	x++;
	99	v = strndup(x, l - strlen(name) - 1);
	100	if (!v)
	101	return -ENOMEM;
	102	}
	103	}
	104	}
	105	}
	106	} else {
	107	char t, s;
	108
	109	stor = strv_split(opts, ",");
	110	if (!stor)
	111	return -ENOMEM;
	112	strv = memdup(stor, sizeof(char) (strv_length(stor) + 1));
	113	if (!strv)
	114	return -ENOMEM;
	115
	116	for (s = t = strv; *s; s++) {
	117	NULSTR_FOREACH(name, names) {
	118	x = startswith(*s, name);
	119	if (x && IN_SET(*x, '\0', '='))
	120	goto found;
	121	}
	122
	123	t = s;
	124	t++;
	125	continue;
	126	found:
127	/* Keep the last occurence found */
128	n = name;
129	if (value) {
130	free(v);
131	if (*x == '\0')
132	v = NULL;
133	else {
134	assert(*x == '=');
135	x++;
136	v = strdup(x);
137	if (!v)
138	return -ENOMEM;
139	}
140	}
141	}
142	*t = NULL;
143	}
144
145	answer:
146	if (namefound)
147	*namefound = n;
148	if (filtered) {
149	char *f;
150
151	f = strv_join(strv, ",");
152	if (!f)
153	return -ENOMEM;
154
155	*filtered = f;
156	}
ae2a15bc LP	157	if (value)
ae2a15bc LP	158	*value = TAKE_PTR(v);
d15d0333 ZJS	159
	160	return !!n;
	161	}
	162
3519d230 KZ	163	int fstab_extract_values(const char opts, const char name, char ***values) {
	164	_cleanup_strv_free_ char optsv = NULL, res = NULL;
	165	char **s;
	166
	167	assert(opts);
	168	assert(name);
	169	assert(values);
	170
	171	optsv = strv_split(opts, ",");
	172	if (!optsv)
	173	return -ENOMEM;
	174
	175	STRV_FOREACH(s, optsv) {
	176	char *arg;
	177	int r;
	178
	179	arg = startswith(*s, name);
	180	if (!arg \|\| *arg != '=')
	181	continue;
	182	r = strv_extend(&res, arg + 1);
	183	if (r < 0)
	184	return r;
	185	}
	186
ae2a15bc	187	*values = TAKE_PTR(res);
3519d230 KZ	188
	189	return !!*values;
	190	}
	191
d15d0333 ZJS	192	int fstab_find_pri(const char options, int ret) {
	193	_cleanup_free_ char *opt = NULL;
	194	int r;
	195	unsigned pri;
	196
	197	assert(ret);
	198
	199	r = fstab_filter_options(options, "pri\0", NULL, &opt, NULL);
a75f4e2a	200	if (r < 0)
d15d0333	201	return r;
a75f4e2a ZJS	202	if (r == 0 \|\| !opt)
a75f4e2a ZJS	203	return 0;
d15d0333 ZJS	204
	205	r = safe_atou(opt, &pri);
	206	if (r < 0)
	207	return r;
	208
c5e04d51 ZJS	209	if ((int) pri < 0)
	210	return -ERANGE;
	211
a75f4e2a	212	*ret = (int) pri;
d15d0333 ZJS	213	return 1;
d15d0333 ZJS	214	}
6550203e LP	215
	216	static char unquote(const char s, const char* quotes) {
	217	size_t l;
	218	assert(s);
	219
	220	/* This is rather stupid, simply removes the heading and
	221	* trailing quotes if there is one. Doesn't care about
	222	* escaping or anything.
	223	*
13e785f7	224	* DON'T USE THIS FOR NEW CODE ANYMORE! */
6550203e LP	225
	226	l = strlen(s);
	227	if (l < 2)
	228	return strdup(s);
	229
	230	if (strchr(quotes, s[0]) && s[l-1] == s[0])
	231	return strndup(s+1, l-2);
	232
	233	return strdup(s);
	234	}
	235
	236	static char tag_to_udev_node(const char tagvalue, const char *by) {
	237	_cleanup_free_ char t = NULL, u = NULL;
	238	size_t enc_len;
	239
	240	u = unquote(tagvalue, QUOTES);
	241	if (!u)
	242	return NULL;
	243
	244	enc_len = strlen(u) * 4 + 1;
	245	t = new(char, enc_len);
	246	if (!t)
	247	return NULL;
	248
	249	if (encode_devnode_name(u, t, enc_len) < 0)
	250	return NULL;
	251
605405c6	252	return strjoin("/dev/disk/by-", by, "/", t);
6550203e LP	253	}
	254
	255	char fstab_node_to_udev_node(const char p) {
	256	assert(p);
	257
	258	if (startswith(p, "LABEL="))
	259	return tag_to_udev_node(p+6, "label");
	260
	261	if (startswith(p, "UUID="))
	262	return tag_to_udev_node(p+5, "uuid");
	263
	264	if (startswith(p, "PARTUUID="))
	265	return tag_to_udev_node(p+9, "partuuid");
	266
	267	if (startswith(p, "PARTLABEL="))
	268	return tag_to_udev_node(p+10, "partlabel");
	269
	270	return strdup(p);
	271	}