Systemd/src/basic/unit-name.c
Lennart Poettering 0c69794138 tree-wide: remove Lennart's copyright lines
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
2018-06-14 10:20:20 +02:00

776 lines
18 KiB
C

/* 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;
}