man: document that some unit types do not support unit aliases via symlinks

[thirdparty/systemd.git] / src / shared / install.h

#pragma once

/***
  This file is part of systemd.

  Copyright 2011 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/>.
***/

typedef enum UnitFileScope UnitFileScope;
typedef enum UnitFileState UnitFileState;
typedef enum UnitFilePresetMode UnitFilePresetMode;
typedef enum UnitFileChangeType UnitFileChangeType;
typedef enum UnitFileType UnitFileType;
typedef struct UnitFileChange UnitFileChange;
typedef struct UnitFileList UnitFileList;
typedef struct UnitFileInstallInfo UnitFileInstallInfo;

#include <stdbool.h>

#include "hashmap.h"
#include "macro.h"
#include "path-lookup.h"
#include "strv.h"
#include "unit-name.h"

enum UnitFileScope {
        UNIT_FILE_SYSTEM,
        UNIT_FILE_GLOBAL,
        UNIT_FILE_USER,
        _UNIT_FILE_SCOPE_MAX,
        _UNIT_FILE_SCOPE_INVALID = -1
};

enum UnitFileState {
        UNIT_FILE_ENABLED,
        UNIT_FILE_ENABLED_RUNTIME,
        UNIT_FILE_LINKED,
        UNIT_FILE_LINKED_RUNTIME,
        UNIT_FILE_MASKED,
        UNIT_FILE_MASKED_RUNTIME,
        UNIT_FILE_STATIC,
        UNIT_FILE_DISABLED,
        UNIT_FILE_INDIRECT,
        UNIT_FILE_GENERATED,
        UNIT_FILE_TRANSIENT,
        UNIT_FILE_BAD,
        _UNIT_FILE_STATE_MAX,
        _UNIT_FILE_STATE_INVALID = -1
};

enum UnitFilePresetMode {
        UNIT_FILE_PRESET_FULL,
        UNIT_FILE_PRESET_ENABLE_ONLY,
        UNIT_FILE_PRESET_DISABLE_ONLY,
        _UNIT_FILE_PRESET_MAX,
        _UNIT_FILE_PRESET_INVALID = -1
};

enum UnitFileChangeType {
        UNIT_FILE_SYMLINK,
        UNIT_FILE_UNLINK,
        UNIT_FILE_IS_MASKED,
        _UNIT_FILE_CHANGE_TYPE_MAX,
        _UNIT_FILE_CHANGE_INVALID = INT_MIN
};

/* type can either one of the UnitFileChangeTypes listed above, or a negative error.
 * If source is specified, it should be the contents of the path symlink.
 * In case of an error, source should be the existing symlink contents or NULL
 */
struct UnitFileChange {
        int type; /* UnitFileChangeType or bust */
        char *path;
        char *source;
};

static inline bool unit_file_changes_have_modification(const UnitFileChange* changes, unsigned n_changes) {
        unsigned i;
        for (i = 0; i < n_changes; i++)
                if (IN_SET(changes[i].type, UNIT_FILE_SYMLINK, UNIT_FILE_UNLINK))
                        return true;
        return false;
}

struct UnitFileList {
        char *path;
        UnitFileState state;
};

enum UnitFileType {
        UNIT_FILE_TYPE_REGULAR,
        UNIT_FILE_TYPE_SYMLINK,
        UNIT_FILE_TYPE_MASKED,
        _UNIT_FILE_TYPE_MAX,
        _UNIT_FILE_TYPE_INVALID = -1,
};

struct UnitFileInstallInfo {
        char *name;
        char *path;

        char **aliases;
        char **wanted_by;
        char **required_by;
        char **also;

        char *default_instance;

        UnitFileType type;

        char *symlink_target;
};

static inline bool UNIT_FILE_INSTALL_INFO_HAS_RULES(UnitFileInstallInfo *i) {
        assert(i);

        return !strv_isempty(i->aliases) ||
               !strv_isempty(i->wanted_by) ||
               !strv_isempty(i->required_by);
}

static inline bool UNIT_FILE_INSTALL_INFO_HAS_ALSO(UnitFileInstallInfo *i) {
        assert(i);

        return !strv_isempty(i->also);
}

int unit_file_enable(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_disable(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_reenable(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_preset(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                UnitFilePresetMode mode,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_preset_all(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                UnitFilePresetMode mode,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_mask(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_unmask(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_link(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_revert(
                UnitFileScope scope,
                const char *root_dir,
                char **files,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_set_default(
                UnitFileScope scope,
                const char *root_dir,
                const char *file,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);
int unit_file_get_default(
                UnitFileScope scope,
                const char *root_dir,
                char **name);
int unit_file_add_dependency(
                UnitFileScope scope,
                bool runtime,
                const char *root_dir,
                char **files,
                const char *target,
                UnitDependency dep,
                bool force,
                UnitFileChange **changes,
                unsigned *n_changes);

int unit_file_get_state(UnitFileScope scope, const char *root_dir, const char *filename, UnitFileState *ret);
int unit_file_exists(UnitFileScope scope, const LookupPaths *paths, const char *name);

int unit_file_get_list(UnitFileScope scope, const char *root_dir, Hashmap *h, char **states, char **patterns);
Hashmap* unit_file_list_free(Hashmap *h);

int unit_file_changes_add(UnitFileChange **changes, unsigned *n_changes, UnitFileChangeType type, const char *path, const char *source);
void unit_file_changes_free(UnitFileChange *changes, unsigned n_changes);
void unit_file_dump_changes(int r, const char *verb, const UnitFileChange *changes, unsigned n_changes, bool quiet);

int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char *name);

const char *unit_file_state_to_string(UnitFileState s) _const_;
UnitFileState unit_file_state_from_string(const char *s) _pure_;
/* from_string conversion is unreliable because of the overlap between -EPERM and -1 for error. */

const char *unit_file_change_type_to_string(UnitFileChangeType s) _const_;
UnitFileChangeType unit_file_change_type_from_string(const char *s) _pure_;

const char *unit_file_preset_mode_to_string(UnitFilePresetMode m) _const_;
UnitFilePresetMode unit_file_preset_mode_from_string(const char *s) _pure_;