/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "alloc-util.h"
#include "glob-util.h"
#include "hexdecoct.h"
#include "path-util.h"
#include "special.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
/* Characters valid in a unit name. */
#define VALID_CHARS \
DIGITS \
LETTERS \
":-_.\\"
/* The same, but also permits the single @ character that may appear */
#define VALID_CHARS_WITH_AT \
"@" \
VALID_CHARS
/* All chars valid in a unit name glob */
#define VALID_CHARS_GLOB \
VALID_CHARS_WITH_AT \
"[]!-*?"
bool unit_name_is_valid(const char *n, UnitNameFlags flags) {
const char *e, *i, *at;
assert((flags & ~(UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE)) == 0);
if (_unlikely_(flags == 0))
return false;
if (isempty(n))
return false;
if (strlen(n) >= UNIT_NAME_MAX)
return false;
e = strrchr(n, '.');
if (!e || e == n)
return false;
if (unit_type_from_string(e + 1) < 0)
return false;
for (i = n, at = NULL; i < e; i++) {
if (*i == '@' && !at)
at = i;
if (!strchr("@" VALID_CHARS, *i))
return false;
}
if (at == n)
return false;
if (flags & UNIT_NAME_PLAIN)
if (!at)
return true;
if (flags & UNIT_NAME_INSTANCE)
if (at && e > at + 1)
return true;
if (flags & UNIT_NAME_TEMPLATE)
if (at && e == at + 1)
return true;
return false;
}
bool unit_prefix_is_valid(const char *p) {
/* We don't allow additional @ in the prefix string */
if (isempty(p))
return false;
return in_charset(p, VALID_CHARS);
}
bool unit_instance_is_valid(const char *i) {
/* The max length depends on the length of the string, so we
* don't really check this here. */
if (isempty(i))
return false;
/* We allow additional @ in the instance string, we do not
* allow them in the prefix! */
return in_charset(i, "@" VALID_CHARS);
}
bool unit_suffix_is_valid(const char *s) {
if (isempty(s))
return false;
if (s[0] != '.')
return false;
if (unit_type_from_string(s + 1) < 0)
return false;
return true;
}
int unit_name_to_prefix(const char *n, char **ret) {
const char *p;
char *s;
assert(n);
assert(ret);
if (!unit_name_is_valid(n, UNIT_NAME_ANY))
return -EINVAL;
p = strchr(n, '@');
if (!p)
p = strrchr(n, '.');
assert_se(p);
s = strndup(n, p - n);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
int unit_name_to_instance(const char *n, char **instance) {
const char *p, *d;
char *i;
assert(n);
assert(instance);
if (!unit_name_is_valid(n, UNIT_NAME_ANY))
return -EINVAL;
/* Everything past the first @ and before the last . is the instance */
p = strchr(n, '@');
if (!p) {
*instance = NULL;
return 0;
}
p++;
d = strrchr(p, '.');
if (!d)
return -EINVAL;
i = strndup(p, d-p);
if (!i)
return -ENOMEM;
*instance = i;
return 1;
}
int unit_name_to_prefix_and_instance(const char *n, char **ret) {
const char *d;
char *s;
assert(n);
assert(ret);
if (!unit_name_is_valid(n, UNIT_NAME_ANY))
return -EINVAL;
d = strrchr(n, '.');
if (!d)
return -EINVAL;
s = strndup(n, d - n);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
UnitType unit_name_to_type(const char *n) {
const char *e;
assert(n);
if (!unit_name_is_valid(n, UNIT_NAME_ANY))
return _UNIT_TYPE_INVALID;
assert_se(e = strrchr(n, '.'));
return unit_type_from_string(e + 1);
}
int unit_name_change_suffix(const char *n, const char *suffix, char **ret) {
char *e, *s;
size_t a, b;
assert(n);
assert(suffix);
assert(ret);
if (!unit_name_is_valid(n, UNIT_NAME_ANY))
return -EINVAL;
if (!unit_suffix_is_valid(suffix))
return -EINVAL;
assert_se(e = strrchr(n, '.'));
a = e - n;
b = strlen(suffix);
s = new(char, a + b + 1);
if (!s)
return -ENOMEM;
strcpy(mempcpy(s, n, a), suffix);
*ret = s;
return 0;
}
int unit_name_build(const char *prefix, const char *instance, const char *suffix, char **ret) {
UnitType type;
assert(prefix);
assert(suffix);
assert(ret);
if (suffix[0] != '.')
return -EINVAL;
type = unit_type_from_string(suffix + 1);
if (type < 0)
return -EINVAL;
return unit_name_build_from_type(prefix, instance, type, ret);
}
int unit_name_build_from_type(const char *prefix, const char *instance, UnitType type, char **ret) {
const char *ut;
char *s;
assert(prefix);
assert(type >= 0);
assert(type < _UNIT_TYPE_MAX);
assert(ret);
if (!unit_prefix_is_valid(prefix))
return -EINVAL;
if (instance && !unit_instance_is_valid(instance))
return -EINVAL;
ut = unit_type_to_string(type);
if (!instance)
s = strjoin(prefix, ".", ut);
else
s = strjoin(prefix, "@", instance, ".", ut);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
static char *do_escape_char(char c, char *t) {
assert(t);
*(t++) = '\\';
*(t++) = 'x';
*(t++) = hexchar(c >> 4);
*(t++) = hexchar(c);
return t;
}
static char *do_escape(const char *f, char *t) {
assert(f);
assert(t);
/* do not create units with a leading '.', like for "/.dotdir" mount points */
if (*f == '.') {
t = do_escape_char(*f, t);
f++;
}
for (; *f; f++) {
if (*f == '/')
*(t++) = '-';
else if (IN_SET(*f, '-', '\\') || !strchr(VALID_CHARS, *f))
t = do_escape_char(*f, t);
else
*(t++) = *f;
}
return t;
}
char *unit_name_escape(const char *f) {
char *r, *t;
assert(f);
r = new(char, strlen(f)*4+1);
if (!r)
return NULL;
t = do_escape(f, r);
*t = 0;
return r;
}
int unit_name_unescape(const char *f, char **ret) {
_cleanup_free_ char *r = NULL;
char *t;
assert(f);
r = strdup(f);
if (!r)
return -ENOMEM;
for (t = r; *f; f++) {
if (*f == '-')
*(t++) = '/';
else if (*f == '\\') {
int a, b;
if (f[1] != 'x')
return -EINVAL;
a = unhexchar(f[2]);
if (a < 0)
return -EINVAL;
b = unhexchar(f[3]);
if (b < 0)
return -EINVAL;
*(t++) = (char) (((uint8_t) a << 4U) | (uint8_t) b);
f += 3;
} else
*(t++) = *f;
}
*t = 0;
*ret = TAKE_PTR(r);
return 0;
}
int unit_name_path_escape(const char *f, char **ret) {
char *p, *s;
assert(f);
assert(ret);
p = strdupa(f);
if (!p)
return -ENOMEM;
path_simplify(p, false);
if (empty_or_root(p))
s = strdup("-");
else {
if (!path_is_normalized(p))
return -EINVAL;
/* Truncate trailing slashes */
delete_trailing_chars(p, "/");
/* Truncate leading slashes */
p = skip_leading_chars(p, "/");
s = unit_name_escape(p);
}
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
int unit_name_path_unescape(const char *f, char **ret) {
char *s;
int r;
assert(f);
if (isempty(f))
return -EINVAL;
if (streq(f, "-")) {
s = strdup("/");
if (!s)
return -ENOMEM;
} else {
char *w;
r = unit_name_unescape(f, &w);
if (r < 0)
return r;
/* Don't accept trailing or leading slashes */
if (startswith(w, "/") || endswith(w, "/")) {
free(w);
return -EINVAL;
}
/* Prefix a slash again */
s = strappend("/", w);
free(w);
if (!s)
return -ENOMEM;
if (!path_is_normalized(s)) {
free(s);
return -EINVAL;
}
}
if (ret)
*ret = s;
else
free(s);
return 0;
}
int unit_name_replace_instance(const char *f, const char *i, char **ret) {
const char *p, *e;
char *s;
size_t a, b;
assert(f);
assert(i);
assert(ret);
if (!unit_name_is_valid(f, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
return -EINVAL;
if (!unit_instance_is_valid(i))
return -EINVAL;
assert_se(p = strchr(f, '@'));
assert_se(e = strrchr(f, '.'));
a = p - f;
b = strlen(i);
s = new(char, a + 1 + b + strlen(e) + 1);
if (!s)
return -ENOMEM;
strcpy(mempcpy(mempcpy(s, f, a + 1), i, b), e);
*ret = s;
return 0;
}
int unit_name_template(const char *f, char **ret) {
const char *p, *e;
char *s;
size_t a;
assert(f);
assert(ret);
if (!unit_name_is_valid(f, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
return -EINVAL;
assert_se(p = strchr(f, '@'));
assert_se(e = strrchr(f, '.'));
a = p - f;
s = new(char, a + 1 + strlen(e) + 1);
if (!s)
return -ENOMEM;
strcpy(mempcpy(s, f, a + 1), e);
*ret = s;
return 0;
}
int unit_name_from_path(const char *path, const char *suffix, char **ret) {
_cleanup_free_ char *p = NULL;
char *s = NULL;
int r;
assert(path);
assert(suffix);
assert(ret);
if (!unit_suffix_is_valid(suffix))
return -EINVAL;
r = unit_name_path_escape(path, &p);
if (r < 0)
return r;
s = strappend(p, suffix);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
int unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix, char **ret) {
_cleanup_free_ char *p = NULL;
char *s;
int r;
assert(prefix);
assert(path);
assert(suffix);
assert(ret);
if (!unit_prefix_is_valid(prefix))
return -EINVAL;
if (!unit_suffix_is_valid(suffix))
return -EINVAL;
r = unit_name_path_escape(path, &p);
if (r < 0)
return r;
s = strjoin(prefix, "@", p, suffix);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
int unit_name_to_path(const char *name, char **ret) {
_cleanup_free_ char *prefix = NULL;
int r;
assert(name);
r = unit_name_to_prefix(name, &prefix);
if (r < 0)
return r;
return unit_name_path_unescape(prefix, ret);
}
static bool do_escape_mangle(const char *f, bool allow_globs, char *t) {
const char *valid_chars;
bool mangled = false;
assert(f);
assert(t);
/* We'll only escape the obvious characters here, to play safe.
*
* Returns true if any characters were mangled, false otherwise.
*/
valid_chars = allow_globs ? VALID_CHARS_GLOB : VALID_CHARS_WITH_AT;
for (; *f; f++)
if (*f == '/') {
*(t++) = '-';
mangled = true;
} else if (!strchr(valid_chars, *f)) {
t = do_escape_char(*f, t);
mangled = true;
} else
*(t++) = *f;
*t = 0;
return mangled;
}
/**
* Convert a string to a unit name. /dev/blah is converted to dev-blah.device,
* /blah/blah is converted to blah-blah.mount, anything else is left alone,
* except that @suffix is appended if a valid unit suffix is not present.
*
* If @allow_globs, globs characters are preserved. Otherwise, they are escaped.
*/
int unit_name_mangle_with_suffix(const char *name, UnitNameMangle flags, const char *suffix, char **ret) {
char *s;
int r;
bool mangled;
assert(name);
assert(suffix);
assert(ret);
if (isempty(name)) /* We cannot mangle empty unit names to become valid, sorry. */
return -EINVAL;
if (!unit_suffix_is_valid(suffix))
return -EINVAL;
/* Already a fully valid unit name? If so, no mangling is necessary... */
if (unit_name_is_valid(name, UNIT_NAME_ANY))
goto good;
/* Already a fully valid globbing expression? If so, no mangling is necessary either... */
if ((flags & UNIT_NAME_MANGLE_GLOB) &&
string_is_glob(name) &&
in_charset(name, VALID_CHARS_GLOB))
goto good;
if (is_device_path(name)) {
r = unit_name_from_path(name, ".device", ret);
if (r >= 0)
return 1;
if (r != -EINVAL)
return r;
}
if (path_is_absolute(name)) {
r = unit_name_from_path(name, ".mount", ret);
if (r >= 0)
return 1;
if (r != -EINVAL)
return r;
}
s = new(char, strlen(name) * 4 + strlen(suffix) + 1);
if (!s)
return -ENOMEM;
mangled = do_escape_mangle(name, flags & UNIT_NAME_MANGLE_GLOB, s);
if (mangled)
log_full(flags & UNIT_NAME_MANGLE_WARN ? LOG_NOTICE : LOG_DEBUG,
"Invalid unit name \"%s\" was escaped as \"%s\" (maybe you should use systemd-escape?)",
name, s);
/* Append a suffix if it doesn't have any, but only if this is not a glob, so that we can allow "foo.*" as a
* valid glob. */
if ((!(flags & UNIT_NAME_MANGLE_GLOB) || !string_is_glob(s)) && unit_name_to_type(s) < 0)
strcat(s, suffix);
*ret = s;
return 1;
good:
s = strdup(name);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
int slice_build_parent_slice(const char *slice, char **ret) {
char *s, *dash;
int r;
assert(slice);
assert(ret);
if (!slice_name_is_valid(slice))
return -EINVAL;
if (streq(slice, SPECIAL_ROOT_SLICE)) {
*ret = NULL;
return 0;
}
s = strdup(slice);
if (!s)
return -ENOMEM;
dash = strrchr(s, '-');
if (dash)
strcpy(dash, ".slice");
else {
r = free_and_strdup(&s, SPECIAL_ROOT_SLICE);
if (r < 0) {
free(s);
return r;
}
}
*ret = s;
return 1;
}
int slice_build_subslice(const char *slice, const char *name, char **ret) {
char *subslice;
assert(slice);
assert(name);
assert(ret);
if (!slice_name_is_valid(slice))
return -EINVAL;
if (!unit_prefix_is_valid(name))
return -EINVAL;
if (streq(slice, SPECIAL_ROOT_SLICE))
subslice = strappend(name, ".slice");
else {
char *e;
assert_se(e = endswith(slice, ".slice"));
subslice = new(char, (e - slice) + 1 + strlen(name) + 6 + 1);
if (!subslice)
return -ENOMEM;
stpcpy(stpcpy(stpcpy(mempcpy(subslice, slice, e - slice), "-"), name), ".slice");
}
*ret = subslice;
return 0;
}
bool slice_name_is_valid(const char *name) {
const char *p, *e;
bool dash = false;
if (!unit_name_is_valid(name, UNIT_NAME_PLAIN))
return false;
if (streq(name, SPECIAL_ROOT_SLICE))
return true;
e = endswith(name, ".slice");
if (!e)
return false;
for (p = name; p < e; p++) {
if (*p == '-') {
/* Don't allow initial dash */
if (p == name)
return false;
/* Don't allow multiple dashes */
if (dash)
return false;
dash = true;
} else
dash = false;
}
/* Don't allow trailing hash */
if (dash)
return false;
return true;
}