Systemd/src/shared/path-lookup.c

895 lines
28 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
/***
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 Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "alloc-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "install.h"
#include "log.h"
#include "macro.h"
#include "mkdir.h"
#include "path-lookup.h"
#include "path-util.h"
#include "rm-rf.h"
#include "stat-util.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "util.h"
int xdg_user_runtime_dir(char **ret, const char *suffix) {
const char *e;
char *j;
assert(ret);
assert(suffix);
e = getenv("XDG_RUNTIME_DIR");
if (!e)
return -ENXIO;
j = strappend(e, suffix);
if (!j)
return -ENOMEM;
*ret = j;
return 0;
}
int xdg_user_config_dir(char **ret, const char *suffix) {
const char *e;
char *j;
int r;
assert(ret);
e = getenv("XDG_CONFIG_HOME");
if (e)
j = strappend(e, suffix);
else {
_cleanup_free_ char *home = NULL;
r = get_home_dir(&home);
if (r < 0)
return r;
j = strjoin(home, "/.config", suffix);
}
if (!j)
return -ENOMEM;
*ret = j;
return 0;
}
int xdg_user_data_dir(char **ret, const char *suffix) {
const char *e;
char *j;
int r;
assert(ret);
assert(suffix);
/* We don't treat /etc/xdg/systemd here as the spec
* suggests because we assume that is a link to
* /etc/systemd/ anyway. */
e = getenv("XDG_DATA_HOME");
if (e)
j = strappend(e, suffix);
else {
_cleanup_free_ char *home = NULL;
r = get_home_dir(&home);
if (r < 0)
return r;
j = strjoin(home, "/.local/share", suffix);
}
if (!j)
return -ENOMEM;
*ret = j;
return 1;
}
static const char* const user_data_unit_paths[] = {
"/usr/local/lib/systemd/user",
"/usr/local/share/systemd/user",
USER_DATA_UNIT_PATH,
"/usr/lib/systemd/user",
"/usr/share/systemd/user",
NULL
};
static const char* const user_config_unit_paths[] = {
USER_CONFIG_UNIT_PATH,
"/etc/systemd/user",
NULL
};
int xdg_user_dirs(char ***ret_config_dirs, char ***ret_data_dirs) {
/* Implement the mechanisms defined in
*
* http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
*
* We look in both the config and the data dirs because we
* want to encourage that distributors ship their unit files
* as data, and allow overriding as configuration.
*/
const char *e;
_cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
e = getenv("XDG_CONFIG_DIRS");
if (e) {
config_dirs = strv_split(e, ":");
if (!config_dirs)
return -ENOMEM;
}
e = getenv("XDG_DATA_DIRS");
if (e)
data_dirs = strv_split(e, ":");
else
data_dirs = strv_new("/usr/local/share",
"/usr/share",
NULL);
if (!data_dirs)
return -ENOMEM;
*ret_config_dirs = config_dirs;
*ret_data_dirs = data_dirs;
config_dirs = data_dirs = NULL;
return 0;
}
static char** user_dirs(
const char *persistent_config,
const char *runtime_config,
const char *global_persistent_config,
const char *global_runtime_config,
const char *generator,
const char *generator_early,
const char *generator_late,
const char *transient,
const char *persistent_control,
const char *runtime_control) {
_cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
_cleanup_free_ char *data_home = NULL;
_cleanup_strv_free_ char **res = NULL;
int r;
r = xdg_user_dirs(&config_dirs, &data_dirs);
if (r < 0)
return NULL;
r = xdg_user_data_dir(&data_home, "/systemd/user");
if (r < 0 && r != -ENXIO)
return NULL;
/* Now merge everything we found. */
if (strv_extend(&res, persistent_control) < 0)
return NULL;
if (strv_extend(&res, runtime_control) < 0)
return NULL;
if (strv_extend(&res, transient) < 0)
return NULL;
if (strv_extend(&res, generator_early) < 0)
return NULL;
if (strv_extend_strv_concat(&res, config_dirs, "/systemd/user") < 0)
return NULL;
if (strv_extend(&res, persistent_config) < 0)
return NULL;
/* global config has lower priority than the user config of the same type */
if (strv_extend(&res, global_persistent_config) < 0)
return NULL;
if (strv_extend_strv(&res, (char**) user_config_unit_paths, false) < 0)
return NULL;
if (strv_extend(&res, runtime_config) < 0)
return NULL;
if (strv_extend(&res, global_runtime_config) < 0)
return NULL;
if (strv_extend(&res, generator) < 0)
return NULL;
if (strv_extend(&res, data_home) < 0)
return NULL;
if (strv_extend_strv_concat(&res, data_dirs, "/systemd/user") < 0)
return NULL;
if (strv_extend_strv(&res, (char**) user_data_unit_paths, false) < 0)
return NULL;
if (strv_extend(&res, generator_late) < 0)
return NULL;
if (path_strv_make_absolute_cwd(res) < 0)
return NULL;
return TAKE_PTR(res);
}
bool path_is_user_data_dir(const char *path) {
assert(path);
return strv_contains((char**) user_data_unit_paths, path);
}
bool path_is_user_config_dir(const char *path) {
assert(path);
return strv_contains((char**) user_config_unit_paths, path);
}
static int acquire_generator_dirs(
UnitFileScope scope,
const char *tempdir,
char **generator,
char **generator_early,
char **generator_late) {
_cleanup_free_ char *x = NULL, *y = NULL, *z = NULL;
const char *prefix;
assert(generator);
assert(generator_early);
assert(generator_late);
assert(IN_SET(scope, UNIT_FILE_SYSTEM, UNIT_FILE_USER, UNIT_FILE_GLOBAL));
if (scope == UNIT_FILE_GLOBAL)
return -EOPNOTSUPP;
if (tempdir)
prefix = tempdir;
else if (scope == UNIT_FILE_SYSTEM)
prefix = "/run/systemd";
else if (scope == UNIT_FILE_USER) {
const char *e;
e = getenv("XDG_RUNTIME_DIR");
if (!e)
return -ENXIO;
prefix = strjoina(e, "/systemd");
}
x = strappend(prefix, "/generator");
if (!x)
return -ENOMEM;
y = strappend(prefix, "/generator.early");
if (!y)
return -ENOMEM;
z = strappend(prefix, "/generator.late");
if (!z)
return -ENOMEM;
*generator = x;
*generator_early = y;
*generator_late = z;
x = y = z = NULL;
return 0;
}
static int acquire_transient_dir(
UnitFileScope scope,
const char *tempdir,
char **ret) {
char *transient;
assert(ret);
assert(IN_SET(scope, UNIT_FILE_SYSTEM, UNIT_FILE_USER, UNIT_FILE_GLOBAL));
if (scope == UNIT_FILE_GLOBAL)
return -EOPNOTSUPP;
if (tempdir)
transient = strjoin(tempdir, "/transient");
else if (scope == UNIT_FILE_SYSTEM)
transient = strdup("/run/systemd/transient");
else
return xdg_user_runtime_dir(ret, "/systemd/transient");
if (!transient)
return -ENOMEM;
*ret = transient;
return 0;
}
static int acquire_config_dirs(UnitFileScope scope, char **persistent, char **runtime) {
_cleanup_free_ char *a = NULL, *b = NULL;
int r;
assert(persistent);
assert(runtime);
switch (scope) {
case UNIT_FILE_SYSTEM:
a = strdup(SYSTEM_CONFIG_UNIT_PATH);
b = strdup("/run/systemd/system");
break;
case UNIT_FILE_GLOBAL:
a = strdup(USER_CONFIG_UNIT_PATH);
b = strdup("/run/systemd/user");
break;
case UNIT_FILE_USER:
r = xdg_user_config_dir(&a, "/systemd/user");
if (r < 0 && r != -ENXIO)
return r;
r = xdg_user_runtime_dir(runtime, "/systemd/user");
if (r < 0) {
if (r != -ENXIO)
return r;
/* If XDG_RUNTIME_DIR is not set, don't consider that fatal, simply initialize the runtime
* directory to NULL */
*runtime = NULL;
}
*persistent = TAKE_PTR(a);
return 0;
default:
assert_not_reached("Hmm, unexpected scope value.");
}
if (!a || !b)
return -ENOMEM;
*persistent = a;
*runtime = b;
a = b = NULL;
return 0;
}
static int acquire_control_dirs(UnitFileScope scope, char **persistent, char **runtime) {
_cleanup_free_ char *a = NULL;
int r;
assert(persistent);
assert(runtime);
switch (scope) {
case UNIT_FILE_SYSTEM: {
_cleanup_free_ char *b = NULL;
a = strdup("/etc/systemd/system.control");
if (!a)
return -ENOMEM;
b = strdup("/run/systemd/system.control");
if (!b)
return -ENOMEM;
*runtime = TAKE_PTR(b);
break;
}
case UNIT_FILE_USER:
r = xdg_user_config_dir(&a, "/systemd/user.control");
if (r < 0 && r != -ENXIO)
return r;
r = xdg_user_runtime_dir(runtime, "/systemd/user.control");
if (r < 0) {
if (r != -ENXIO)
return r;
/* If XDG_RUNTIME_DIR is not set, don't consider this fatal, simply initialize the directory to
* NULL */
*runtime = NULL;
}
break;
case UNIT_FILE_GLOBAL:
return -EOPNOTSUPP;
default:
assert_not_reached("Hmm, unexpected scope value.");
}
*persistent = TAKE_PTR(a);
return 0;
}
static int patch_root_prefix(char **p, const char *root_dir) {
char *c;
assert(p);
if (!*p)
return 0;
c = prefix_root(root_dir, *p);
if (!c)
return -ENOMEM;
free(*p);
*p = c;
return 0;
}
static int patch_root_prefix_strv(char **l, const char *root_dir) {
char **i;
int r;
if (!root_dir)
return 0;
STRV_FOREACH(i, l) {
r = patch_root_prefix(i, root_dir);
if (r < 0)
return r;
}
return 0;
}
int lookup_paths_init(
LookupPaths *p,
UnitFileScope scope,
LookupPathsFlags flags,
const char *root_dir) {
_cleanup_(rmdir_and_freep) char *tempdir = NULL;
_cleanup_free_ char
*root = NULL,
*persistent_config = NULL, *runtime_config = NULL,
*global_persistent_config = NULL, *global_runtime_config = NULL,
*generator = NULL, *generator_early = NULL, *generator_late = NULL,
*transient = NULL,
*persistent_control = NULL, *runtime_control = NULL;
bool append = false; /* Add items from SYSTEMD_UNIT_PATH before normal directories */
_cleanup_strv_free_ char **paths = NULL;
const char *e;
int r;
assert(p);
assert(scope >= 0);
assert(scope < _UNIT_FILE_SCOPE_MAX);
if (!isempty(root_dir) && !path_equal(root_dir, "/")) {
if (scope == UNIT_FILE_USER)
return -EINVAL;
r = is_dir(root_dir, true);
if (r < 0)
return r;
if (r == 0)
return -ENOTDIR;
root = strdup(root_dir);
if (!root)
return -ENOMEM;
}
if (flags & LOOKUP_PATHS_TEMPORARY_GENERATED) {
r = mkdtemp_malloc("/tmp/systemd-temporary-XXXXXX", &tempdir);
if (r < 0)
return log_error_errno(r, "Failed to create temporary directory: %m");
}
/* Note: when XDG_RUNTIME_DIR is not set this will not return -ENXIO, but simply set runtime_config to NULL */
r = acquire_config_dirs(scope, &persistent_config, &runtime_config);
if (r < 0)
return r;
if (scope == UNIT_FILE_USER) {
r = acquire_config_dirs(UNIT_FILE_GLOBAL, &global_persistent_config, &global_runtime_config);
if (r < 0)
return r;
}
if ((flags & LOOKUP_PATHS_EXCLUDE_GENERATED) == 0) {
/* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
r = acquire_generator_dirs(scope, tempdir,
&generator, &generator_early, &generator_late);
if (r < 0 && !IN_SET(r, -EOPNOTSUPP, -ENXIO))
return r;
}
/* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
r = acquire_transient_dir(scope, tempdir, &transient);
if (r < 0 && !IN_SET(r, -EOPNOTSUPP, -ENXIO))
return r;
/* Note: when XDG_RUNTIME_DIR is not set this will not return -ENXIO, but simply set runtime_control to NULL */
r = acquire_control_dirs(scope, &persistent_control, &runtime_control);
if (r < 0 && r != -EOPNOTSUPP)
return r;
/* First priority is whatever has been passed to us via env vars */
e = getenv("SYSTEMD_UNIT_PATH");
if (e) {
const char *k;
k = endswith(e, ":");
if (k) {
e = strndupa(e, k - e);
append = true;
}
/* FIXME: empty components in other places should be rejected. */
r = path_split_and_make_absolute(e, &paths);
if (r < 0)
return r;
}
if (!paths || append) {
/* Let's figure something out. */
_cleanup_strv_free_ char **add = NULL;
/* For the user units we include share/ in the search
* path in order to comply with the XDG basedir spec.
* For the system stuff we avoid such nonsense. OTOH
* we include /lib in the search path for the system
* stuff but avoid it for user stuff. */
switch (scope) {
case UNIT_FILE_SYSTEM:
add = strv_new(
/* If you modify this you also want to modify
* systemdsystemunitpath= in systemd.pc.in! */
STRV_IFNOTNULL(persistent_control),
STRV_IFNOTNULL(runtime_control),
STRV_IFNOTNULL(transient),
STRV_IFNOTNULL(generator_early),
persistent_config,
SYSTEM_CONFIG_UNIT_PATH,
"/etc/systemd/system",
runtime_config,
"/run/systemd/system",
STRV_IFNOTNULL(generator),
"/usr/local/lib/systemd/system",
SYSTEM_DATA_UNIT_PATH,
"/usr/lib/systemd/system",
#if HAVE_SPLIT_USR
"/lib/systemd/system",
#endif
STRV_IFNOTNULL(generator_late),
NULL);
break;
case UNIT_FILE_GLOBAL:
add = strv_new(
/* If you modify this you also want to modify
* systemduserunitpath= in systemd.pc.in, and
* the arrays in user_dirs() above! */
STRV_IFNOTNULL(persistent_control),
STRV_IFNOTNULL(runtime_control),
STRV_IFNOTNULL(transient),
STRV_IFNOTNULL(generator_early),
persistent_config,
USER_CONFIG_UNIT_PATH,
"/etc/systemd/user",
runtime_config,
"/run/systemd/user",
STRV_IFNOTNULL(generator),
"/usr/local/share/systemd/user",
"/usr/share/systemd/user",
"/usr/local/lib/systemd/user",
USER_DATA_UNIT_PATH,
"/usr/lib/systemd/user",
STRV_IFNOTNULL(generator_late),
NULL);
break;
case UNIT_FILE_USER:
add = user_dirs(persistent_config, runtime_config,
global_persistent_config, global_runtime_config,
generator, generator_early, generator_late,
transient,
persistent_control, runtime_control);
break;
default:
assert_not_reached("Hmm, unexpected scope?");
}
if (!add)
return -ENOMEM;
if (paths) {
r = strv_extend_strv(&paths, add, true);
if (r < 0)
return r;
} else {
/* Small optimization: if paths is NULL (and it usually is), we can simply assign 'add' to it,
* and don't have to copy anything */
paths = add;
add = NULL;
}
}
r = patch_root_prefix(&persistent_config, root);
if (r < 0)
return r;
r = patch_root_prefix(&runtime_config, root);
if (r < 0)
return r;
r = patch_root_prefix(&generator, root);
if (r < 0)
return r;
r = patch_root_prefix(&generator_early, root);
if (r < 0)
return r;
r = patch_root_prefix(&generator_late, root);
if (r < 0)
return r;
r = patch_root_prefix(&transient, root);
if (r < 0)
return r;
r = patch_root_prefix(&persistent_control, root);
if (r < 0)
return r;
r = patch_root_prefix(&runtime_control, root);
if (r < 0)
return r;
r = patch_root_prefix_strv(paths, root);
if (r < 0)
return -ENOMEM;
p->search_path = strv_uniq(paths);
paths = NULL;
p->persistent_config = persistent_config;
p->runtime_config = runtime_config;
persistent_config = runtime_config = NULL;
p->generator = generator;
p->generator_early = generator_early;
p->generator_late = generator_late;
generator = generator_early = generator_late = NULL;
p->transient = transient;
transient = NULL;
p->persistent_control = persistent_control;
p->runtime_control = runtime_control;
persistent_control = runtime_control = NULL;
p->root_dir = root;
root = NULL;
p->temporary_dir = tempdir;
tempdir = NULL;
return 0;
}
void lookup_paths_free(LookupPaths *p) {
if (!p)
return;
p->search_path = strv_free(p->search_path);
p->persistent_config = mfree(p->persistent_config);
p->runtime_config = mfree(p->runtime_config);
p->generator = mfree(p->generator);
p->generator_early = mfree(p->generator_early);
p->generator_late = mfree(p->generator_late);
p->transient = mfree(p->transient);
p->persistent_control = mfree(p->persistent_control);
p->runtime_control = mfree(p->runtime_control);
p->root_dir = mfree(p->root_dir);
p->temporary_dir = mfree(p->temporary_dir);
}
int lookup_paths_reduce(LookupPaths *p) {
_cleanup_free_ struct stat *stats = NULL;
size_t n_stats = 0, allocated = 0;
unsigned c = 0;
int r;
assert(p);
/* Drop duplicates and non-existing directories from the search path. We figure out whether two directories are
* the same by comparing their device and inode numbers. Note one special tweak: when we have a root path set,
* we do not follow symlinks when retrieving them, because the kernel wouldn't take the root prefix into
* account when following symlinks. When we have no root path set this restriction does not apply however. */
if (!p->search_path)
return 0;
while (p->search_path[c]) {
struct stat st;
unsigned k;
/* Never strip the transient and control directories from the path */
if (path_equal_ptr(p->search_path[c], p->transient) ||
path_equal_ptr(p->search_path[c], p->persistent_control) ||
path_equal_ptr(p->search_path[c], p->runtime_control)) {
c++;
continue;
}
if (p->root_dir)
r = lstat(p->search_path[c], &st);
else
r = stat(p->search_path[c], &st);
if (r < 0) {
if (errno == ENOENT)
goto remove_item;
/* If something we don't grok happened, let's better leave it in. */
log_debug_errno(errno, "Failed to stat %s: %m", p->search_path[c]);
c++;
continue;
}
for (k = 0; k < n_stats; k++) {
if (stats[k].st_dev == st.st_dev &&
stats[k].st_ino == st.st_ino)
break;
}
if (k < n_stats) /* Is there already an entry with the same device/inode? */
goto remove_item;
if (!GREEDY_REALLOC(stats, allocated, n_stats+1))
return -ENOMEM;
stats[n_stats++] = st;
c++;
continue;
remove_item:
free(p->search_path[c]);
memmove(p->search_path + c,
p->search_path + c + 1,
(strv_length(p->search_path + c + 1) + 1) * sizeof(char*));
}
if (strv_isempty(p->search_path)) {
log_debug("Ignoring unit files.");
p->search_path = strv_free(p->search_path);
} else {
_cleanup_free_ char *t;
t = strv_join(p->search_path, "\n\t");
if (!t)
return -ENOMEM;
log_debug("Looking for unit files in (higher priority first):\n\t%s", t);
}
return 0;
}
int lookup_paths_mkdir_generator(LookupPaths *p) {
int r, q;
assert(p);
if (!p->generator || !p->generator_early || !p->generator_late)
return -EINVAL;
r = mkdir_p_label(p->generator, 0755);
q = mkdir_p_label(p->generator_early, 0755);
if (q < 0 && r >= 0)
r = q;
q = mkdir_p_label(p->generator_late, 0755);
if (q < 0 && r >= 0)
r = q;
return r;
}
void lookup_paths_trim_generator(LookupPaths *p) {
assert(p);
/* Trim empty dirs */
if (p->generator)
(void) rmdir(p->generator);
if (p->generator_early)
(void) rmdir(p->generator_early);
if (p->generator_late)
(void) rmdir(p->generator_late);
}
void lookup_paths_flush_generator(LookupPaths *p) {
assert(p);
/* Flush the generated unit files in full */
if (p->generator)
(void) rm_rf(p->generator, REMOVE_ROOT);
if (p->generator_early)
(void) rm_rf(p->generator_early, REMOVE_ROOT);
if (p->generator_late)
(void) rm_rf(p->generator_late, REMOVE_ROOT);
if (p->temporary_dir)
(void) rm_rf(p->temporary_dir, REMOVE_ROOT);
}
char **generator_binary_paths(UnitFileScope scope) {
switch (scope) {
case UNIT_FILE_SYSTEM:
return strv_new("/run/systemd/system-generators",
"/etc/systemd/system-generators",
"/usr/local/lib/systemd/system-generators",
SYSTEM_GENERATOR_PATH,
NULL);
case UNIT_FILE_GLOBAL:
case UNIT_FILE_USER:
return strv_new("/run/systemd/user-generators",
"/etc/systemd/user-generators",
"/usr/local/lib/systemd/user-generators",
USER_GENERATOR_PATH,
NULL);
default:
assert_not_reached("Hmm, unexpected scope.");
}
}