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systemd/src/unit-name.c

425 lines
9.7 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <string.h>
#include "unit.h"
#include "unit-name.h"
#define VALID_CHARS \
"0123456789" \
"abcdefghijklmnopqrstuvwxyz" \
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
":-_.\\"
UnitType unit_name_to_type(const char *n) {
UnitType t;
assert(n);
for (t = 0; t < _UNIT_TYPE_MAX; t++)
if (endswith(n, unit_vtable[t]->suffix))
return t;
return _UNIT_TYPE_INVALID;
}
bool unit_name_is_valid(const char *n) {
UnitType t;
const char *e, *i, *at;
/* Valid formats:
*
* string@instance.suffix
* string.suffix
*/
assert(n);
if (strlen(n) >= UNIT_NAME_MAX)
return false;
t = unit_name_to_type(n);
if (t < 0 || t >= _UNIT_TYPE_MAX)
return false;
assert_se(e = strrchr(n, '.'));
if (e == n)
return false;
for (i = n, at = NULL; i < e; i++) {
if (*i == '@' && !at)
at = i;
if (!strchr("@" VALID_CHARS, *i))
return false;
}
if (at) {
if (at == n)
return false;
if (at[1] == '.')
return false;
}
return true;
}
bool unit_instance_is_valid(const char *i) {
assert(i);
/* The max length depends on the length of the string, so we
* don't really check this here. */
if (i[0] == 0)
return false;
/* We allow additional @ in the instance string, we do not
* allow them in the prefix! */
for (; *i; i++)
if (!strchr("@" VALID_CHARS, *i))
return false;
return true;
}
bool unit_prefix_is_valid(const char *p) {
/* We don't allow additional @ in the instance string */
if (p[0] == 0)
return false;
for (; *p; p++)
if (!strchr(VALID_CHARS, *p))
return false;
return true;
}
int unit_name_to_instance(const char *n, char **instance) {
const char *p, *d;
char *i;
assert(n);
assert(instance);
/* Everything past the first @ and before the last . is the instance */
if (!(p = strchr(n, '@'))) {
*instance = NULL;
return 0;
}
assert_se(d = strrchr(n, '.'));
assert(p < d);
if (!(i = strndup(p+1, d-p-1)))
return -ENOMEM;
*instance = i;
return 0;
}
char *unit_name_to_prefix_and_instance(const char *n) {
const char *d;
assert(n);
assert_se(d = strrchr(n, '.'));
return strndup(n, d - n);
}
char *unit_name_to_prefix(const char *n) {
const char *p;
if ((p = strchr(n, '@')))
return strndup(n, p - n);
return unit_name_to_prefix_and_instance(n);
}
char *unit_name_change_suffix(const char *n, const char *suffix) {
char *e, *r;
size_t a, b;
assert(n);
assert(unit_name_is_valid(n));
assert(suffix);
assert_se(e = strrchr(n, '.'));
a = e - n;
b = strlen(suffix);
if (!(r = new(char, a + b + 1)))
return NULL;
memcpy(r, n, a);
memcpy(r+a, suffix, b+1);
return r;
}
char *unit_name_build(const char *prefix, const char *instance, const char *suffix) {
char *r;
assert(prefix);
assert(unit_prefix_is_valid(prefix));
assert(!instance || unit_instance_is_valid(instance));
assert(suffix);
assert(unit_name_to_type(suffix) >= 0);
if (!instance)
return strappend(prefix, suffix);
if (asprintf(&r, "%s@%s%s", prefix, instance, suffix) < 0)
return NULL;
return r;
}
static char* do_escape(const char *f, char *t) {
assert(f);
assert(t);
for (; *f; f++) {
if (*f == '/')
*(t++) = '-';
else if (*f == '-' || *f == '\\' || !strchr(VALID_CHARS, *f)) {
*(t++) = '\\';
*(t++) = 'x';
*(t++) = hexchar(*f > 4);
*(t++) = hexchar(*f);
} else
*(t++) = *f;
}
return t;
}
char *unit_name_build_escape(const char *prefix, const char *instance, const char *suffix) {
char *r, *t;
size_t a, b, c;
assert(prefix);
assert(suffix);
assert(unit_name_to_type(suffix) >= 0);
/* Takes a arbitrary string for prefix and instance plus a
* suffix and makes a nice string suitable as unit name of it,
* escaping all weird chars on the way.
*
* / becomes ., and all chars not alloweed in a unit name get
* escaped as \xFF, including \ and ., of course. This
* escaping is hence reversible.
*
* This is primarily useful to make nice unit names from
* strings, but is actually useful for any kind of string.
*/
a = strlen(prefix);
c = strlen(suffix);
if (instance) {
b = strlen(instance);
if (!(r = new(char, a*4 + 1 + b*4 + c + 1)))
return NULL;
t = do_escape(prefix, r);
*(t++) = '@';
t = do_escape(instance, t);
} else {
if (!(r = new(char, a*4 + c + 1)))
return NULL;
t = do_escape(prefix, r);
}
strcpy(t, suffix);
return r;
}
char *unit_name_escape(const char *f) {
char *r, *t;
if (!(r = new(char, strlen(f)*4+1)))
return NULL;
t = do_escape(f, r);
*t = 0;
return r;
}
char *unit_name_unescape(const char *f) {
char *r, *t;
assert(f);
if (!(r = strdup(f)))
return NULL;
for (t = r; *f; f++) {
if (*f == '-')
*(t++) = '/';
else if (*f == '\\') {
int a, b;
if ((a = unhexchar(f[1])) < 0 ||
(b = unhexchar(f[2])) < 0) {
/* Invalid escape code, let's take it literal then */
*(t++) = '\\';
} else {
*(t++) = (char) ((a << 4) | b);
f += 2;
}
} else
*(t++) = *f;
}
*t = 0;
return r;
}
bool unit_name_is_template(const char *n) {
const char *p;
assert(n);
if (!(p = strchr(n, '@')))
return false;
return p[1] == '.';
}
char *unit_name_replace_instance(const char *f, const char *i) {
const char *p, *e;
char *r, *k;
size_t a;
assert(f);
p = strchr(f, '@');
assert_se(e = strrchr(f, '.'));
a = p - f;
if (p) {
size_t b;
b = strlen(i);
if (!(r = new(char, a + 1 + b + strlen(e) + 1)))
return NULL;
k = mempcpy(r, f, a + 1);
k = mempcpy(k, i, b);
} else {
if (!(r = new(char, a + strlen(e) + 1)))
return NULL;
k = mempcpy(r, f, a);
}
strcpy(k, e);
return r;
}
char *unit_name_template(const char *f) {
const char *p, *e;
char *r;
size_t a;
if (!(p = strchr(f, '@')))
return strdup(f);
assert_se(e = strrchr(f, '.'));
a = p - f + 1;
if (!(r = new(char, a + strlen(e) + 1)))
return NULL;
strcpy(mempcpy(r, f, a), e);
return r;
}
char *unit_name_from_path(const char *path, const char *suffix) {
char *p, *r;
assert(path);
assert(suffix);
if (!(p = strdup(path)))
return NULL;
path_kill_slashes(p);
path = p[0] == '/' ? p + 1 : p;
if (path[0] == 0) {
free(p);
return strappend("-", suffix);
}
r = unit_name_build_escape(path, NULL, suffix);
free(p);
return r;
}
char *unit_name_to_path(const char *name) {
char *w, *e;
assert(name);
if (!(w = unit_name_to_prefix(name)))
return NULL;
e = unit_name_unescape(w);
free(w);
if (!e)
return NULL;
if (e[0] != '/') {
w = strappend("/", e);
free(e);
if (!w)
return NULL;
e = w;
}
return e;
}