busctl: improve readability a bit

[thirdparty/systemd.git] / src / systemd / sd-bus.h

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

#ifndef foosdbushfoo
#define foosdbushfoo

/***
  This file is part of systemd.

  Copyright 2013 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 <inttypes.h>
#include <sys/types.h>
#include <sys/uio.h>

#include "sd-id128.h"
#include "sd-event.h"
#include "_sd-common.h"

_SD_BEGIN_DECLARATIONS;

/* Types */

typedef struct sd_bus sd_bus;
typedef struct sd_bus_message sd_bus_message;
typedef struct sd_bus_slot sd_bus_slot;
typedef struct sd_bus_creds sd_bus_creds;
typedef struct sd_bus_track sd_bus_track;

typedef struct {
        const char *name;
        const char *message;
        int _need_free;
} sd_bus_error;

/* Flags */

enum {
        SD_BUS_CREDS_PID              = 1ULL << 0,
        SD_BUS_CREDS_PID_STARTTIME    = 1ULL << 1,
        SD_BUS_CREDS_TID              = 1ULL << 2,
        SD_BUS_CREDS_UID              = 1ULL << 3,
        SD_BUS_CREDS_GID              = 1ULL << 4,
        SD_BUS_CREDS_COMM             = 1ULL << 5,
        SD_BUS_CREDS_TID_COMM         = 1ULL << 6,
        SD_BUS_CREDS_EXE              = 1ULL << 7,
        SD_BUS_CREDS_CMDLINE          = 1ULL << 8,
        SD_BUS_CREDS_CGROUP           = 1ULL << 9,
        SD_BUS_CREDS_UNIT             = 1ULL << 10,
        SD_BUS_CREDS_USER_UNIT        = 1ULL << 11,
        SD_BUS_CREDS_SLICE            = 1ULL << 12,
        SD_BUS_CREDS_SESSION          = 1ULL << 13,
        SD_BUS_CREDS_OWNER_UID        = 1ULL << 14,
        SD_BUS_CREDS_EFFECTIVE_CAPS   = 1ULL << 15,
        SD_BUS_CREDS_PERMITTED_CAPS   = 1ULL << 16,
        SD_BUS_CREDS_INHERITABLE_CAPS = 1ULL << 17,
        SD_BUS_CREDS_BOUNDING_CAPS    = 1ULL << 18,
        SD_BUS_CREDS_SELINUX_CONTEXT  = 1ULL << 19,
        SD_BUS_CREDS_AUDIT_SESSION_ID = 1ULL << 20,
        SD_BUS_CREDS_AUDIT_LOGIN_UID  = 1ULL << 21,
        SD_BUS_CREDS_UNIQUE_NAME      = 1ULL << 22,
        SD_BUS_CREDS_WELL_KNOWN_NAMES = 1ULL << 23,
        SD_BUS_CREDS_DESCRIPTION      = 1ULL << 24,
        _SD_BUS_CREDS_ALL             = (1ULL << 25) -1,
};

enum {
        SD_BUS_NAME_REPLACE_EXISTING  = 1ULL << 0,
        SD_BUS_NAME_ALLOW_REPLACEMENT = 1ULL << 1,
        SD_BUS_NAME_QUEUE             = 1ULL << 2,
};

/* Callbacks */

typedef int (*sd_bus_message_handler_t)(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *ret_error);
typedef int (*sd_bus_property_get_t) (sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *reply, void *userdata, sd_bus_error *ret_error);
typedef int (*sd_bus_property_set_t) (sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *value, void *userdata, sd_bus_error *ret_error);
typedef int (*sd_bus_object_find_t) (sd_bus *bus, const char *path, const char *interface, void *userdata, void **ret_found, sd_bus_error *ret_error);
typedef int (*sd_bus_node_enumerator_t) (sd_bus *bus, const char *path, void *userdata, char ***ret_nodes, sd_bus_error *ret_error);
typedef int (*sd_bus_track_handler_t) (sd_bus_track *track, void *userdata);

#include "sd-bus-protocol.h"
#include "sd-bus-vtable.h"

/* Connections */

int sd_bus_default(sd_bus **ret);
int sd_bus_default_user(sd_bus **ret);
int sd_bus_default_system(sd_bus **ret);

int sd_bus_open(sd_bus **ret);
int sd_bus_open_user(sd_bus **ret);
int sd_bus_open_system(sd_bus **ret);
int sd_bus_open_system_remote(sd_bus **ret, const char *host);
int sd_bus_open_system_container(sd_bus **ret, const char *machine);

int sd_bus_new(sd_bus **ret);
int sd_bus_set_address(sd_bus *bus, const char *address);
int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd);
int sd_bus_set_exec(sd_bus *bus, const char *path, char *const argv[]);
int sd_bus_set_bus_client(sd_bus *bus, int b);
int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t owner_id);
int sd_bus_set_anonymous(sd_bus *bus, int b);
int sd_bus_set_trusted(sd_bus *bus, int b);
int sd_bus_set_description(sd_bus *bus, const char *description);
int sd_bus_set_monitor(sd_bus *bus, int b);
int sd_bus_negotiate_fds(sd_bus *bus, int b);
int sd_bus_negotiate_timestamp(sd_bus *bus, int b);
int sd_bus_negotiate_creds(sd_bus *bus, uint64_t creds_mask);
int sd_bus_start(sd_bus *ret);

int sd_bus_try_close(sd_bus *bus);
void sd_bus_close(sd_bus *bus);

sd_bus *sd_bus_ref(sd_bus *bus);
sd_bus *sd_bus_unref(sd_bus *bus);

int sd_bus_is_open(sd_bus *bus);
int sd_bus_can_send(sd_bus *bus, char type);
int sd_bus_get_owner_id(sd_bus *bus, sd_id128_t *id);
int sd_bus_get_owner_creds(sd_bus *bus, uint64_t creds_mask, sd_bus_creds **ret);
int sd_bus_get_description(sd_bus *bus, const char **description);
int sd_bus_get_tid(sd_bus *bus, pid_t *tid);

int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *cookie);
int sd_bus_send_to(sd_bus *bus, sd_bus_message *m, const char *destination, uint64_t *cookie);
int sd_bus_call(sd_bus *bus, sd_bus_message *m, uint64_t usec, sd_bus_error *ret_error, sd_bus_message **reply);
int sd_bus_call_async(sd_bus *bus, sd_bus_slot **slot, sd_bus_message *m, sd_bus_message_handler_t callback, void *userdata, uint64_t usec);

int sd_bus_get_fd(sd_bus *bus);
int sd_bus_get_events(sd_bus *bus);
int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec);
int sd_bus_process(sd_bus *bus, sd_bus_message **r);
int sd_bus_process_priority(sd_bus *bus, int64_t max_priority, sd_bus_message **r);
int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec);
int sd_bus_flush(sd_bus *bus);

sd_bus_slot* sd_bus_get_current_slot(sd_bus *bus);
sd_bus_message* sd_bus_get_current_message(sd_bus *bus);
sd_bus_message_handler_t sd_bus_get_current_handler(sd_bus *bus);
void* sd_bus_get_current_userdata(sd_bus *bus);

int sd_bus_attach_event(sd_bus *bus, sd_event *e, int priority);
int sd_bus_detach_event(sd_bus *bus);
sd_event *sd_bus_get_event(sd_bus *bus);

int sd_bus_add_filter(sd_bus *bus, sd_bus_slot **slot, sd_bus_message_handler_t callback, void *userdata);
int sd_bus_add_match(sd_bus *bus, sd_bus_slot **slot, const char *match, sd_bus_message_handler_t callback, void *userdata);
int sd_bus_add_object(sd_bus *bus, sd_bus_slot **slot, const char *path, sd_bus_message_handler_t callback, void *userdata);
int sd_bus_add_fallback(sd_bus *bus, sd_bus_slot **slot, const char *prefix, sd_bus_message_handler_t callback, void *userdata);
int sd_bus_add_object_vtable(sd_bus *bus, sd_bus_slot **slot, const char *path, const char *interface, const sd_bus_vtable *vtable, void *userdata);
int sd_bus_add_fallback_vtable(sd_bus *bus, sd_bus_slot **slot, const char *prefix, const char *interface, const sd_bus_vtable *vtable, sd_bus_object_find_t find, void *userdata);
int sd_bus_add_node_enumerator(sd_bus *bus, sd_bus_slot **slot, const char *path, sd_bus_node_enumerator_t callback, void *userdata);
int sd_bus_add_object_manager(sd_bus *bus, sd_bus_slot **slot, const char *path);

/* Slot object */

sd_bus_slot* sd_bus_slot_ref(sd_bus_slot *slot);
sd_bus_slot* sd_bus_slot_unref(sd_bus_slot *slot);

sd_bus* sd_bus_slot_get_bus(sd_bus_slot *slot);
void *sd_bus_slot_get_userdata(sd_bus_slot *slot);
void *sd_bus_slot_set_userdata(sd_bus_slot *slot, void *userdata);
int sd_bus_slot_set_description(sd_bus_slot *slot, const char *description);
int sd_bus_slot_get_description(sd_bus_slot *slot, char **description);

sd_bus_message* sd_bus_slot_get_current_message(sd_bus_slot *slot);
sd_bus_message_handler_t sd_bus_slot_get_current_handler(sd_bus_slot *bus);
void *sd_bus_slot_get_current_userdata(sd_bus_slot *slot);

/* Message object */

int sd_bus_message_new_signal(sd_bus *bus, sd_bus_message **m, const char *path, const char *interface, const char *member);
int sd_bus_message_new_method_call(sd_bus *bus, sd_bus_message **m, const char *destination, const char *path, const char *interface, const char *member);
int sd_bus_message_new_method_return(sd_bus_message *call, sd_bus_message **m);
int sd_bus_message_new_method_error(sd_bus_message *call, sd_bus_message **m, const sd_bus_error *e);
int sd_bus_message_new_method_errorf(sd_bus_message *call, sd_bus_message **m, const char *name, const char *format, ...) _sd_printf_(4, 5);
int sd_bus_message_new_method_errno(sd_bus_message *call, sd_bus_message **m, int error, const sd_bus_error *e);
int sd_bus_message_new_method_errnof(sd_bus_message *call, sd_bus_message **m, int error, const char *format, ...) _sd_printf_(4, 5);

sd_bus_message* sd_bus_message_ref(sd_bus_message *m);
sd_bus_message* sd_bus_message_unref(sd_bus_message *m);

int sd_bus_message_get_type(sd_bus_message *m, uint8_t *type);
int sd_bus_message_get_cookie(sd_bus_message *m, uint64_t *cookie);
int sd_bus_message_get_reply_cookie(sd_bus_message *m, uint64_t *cookie);
int sd_bus_message_get_priority(sd_bus_message *m, int64_t *priority);

int sd_bus_message_get_expect_reply(sd_bus_message *m);
int sd_bus_message_get_auto_start(sd_bus_message *m);
int sd_bus_message_get_allow_interactive_authorization(sd_bus_message *m);

const char *sd_bus_message_get_signature(sd_bus_message *m, int complete);
const char *sd_bus_message_get_path(sd_bus_message *m);
const char *sd_bus_message_get_interface(sd_bus_message *m);
const char *sd_bus_message_get_member(sd_bus_message *m);
const char *sd_bus_message_get_destination(sd_bus_message *m);
const char *sd_bus_message_get_sender(sd_bus_message *m);
const sd_bus_error *sd_bus_message_get_error(sd_bus_message *m);
int sd_bus_message_get_errno(sd_bus_message *m);

int sd_bus_message_get_monotonic_usec(sd_bus_message *m, uint64_t *usec);
int sd_bus_message_get_realtime_usec(sd_bus_message *m, uint64_t *usec);
int sd_bus_message_get_seqnum(sd_bus_message *m, uint64_t* seqnum);

sd_bus* sd_bus_message_get_bus(sd_bus_message *m);
sd_bus_creds *sd_bus_message_get_creds(sd_bus_message *m); /* do not unref the result */

int sd_bus_message_is_signal(sd_bus_message *m, const char *interface, const char *member);
int sd_bus_message_is_method_call(sd_bus_message *m, const char *interface, const char *member);
int sd_bus_message_is_method_error(sd_bus_message *m, const char *name);
int sd_bus_message_is_empty(sd_bus_message *m);

int sd_bus_message_set_expect_reply(sd_bus_message *m, int b);
int sd_bus_message_set_auto_start(sd_bus_message *m, int b);
int sd_bus_message_set_allow_interactive_authorization(sd_bus_message *m, int b);

int sd_bus_message_set_destination(sd_bus_message *m, const char *destination);
int sd_bus_message_set_priority(sd_bus_message *m, int64_t priority);

int sd_bus_message_append(sd_bus_message *m, const char *types, ...);
int sd_bus_message_append_basic(sd_bus_message *m, char type, const void *p);
int sd_bus_message_append_array(sd_bus_message *m, char type, const void *ptr, size_t size);
int sd_bus_message_append_array_space(sd_bus_message *m, char type, size_t size, void **ptr);
int sd_bus_message_append_array_iovec(sd_bus_message *m, char type, const struct iovec *iov, unsigned n);
int sd_bus_message_append_array_memfd(sd_bus_message *m, char type, int memfd);
int sd_bus_message_append_string_space(sd_bus_message *m, size_t size, char **s);
int sd_bus_message_append_string_iovec(sd_bus_message *m, const struct iovec *iov, unsigned n);
int sd_bus_message_append_string_memfd(sd_bus_message *m, int memfd);
int sd_bus_message_append_strv(sd_bus_message *m, char **l);
int sd_bus_message_open_container(sd_bus_message *m, char type, const char *contents);
int sd_bus_message_close_container(sd_bus_message *m);
int sd_bus_message_copy(sd_bus_message *m, sd_bus_message *source, int all);

int sd_bus_message_read(sd_bus_message *m, const char *types, ...);
int sd_bus_message_read_basic(sd_bus_message *m, char type, void *p);
int sd_bus_message_read_array(sd_bus_message *m, char type, const void **ptr, size_t *size);
int sd_bus_message_read_strv(sd_bus_message *m, char ***l); /* free the result! */
int sd_bus_message_skip(sd_bus_message *m, const char *types);
int sd_bus_message_enter_container(sd_bus_message *m, char type, const char *contents);
int sd_bus_message_exit_container(sd_bus_message *m);
int sd_bus_message_peek_type(sd_bus_message *m, char *type, const char **contents);
int sd_bus_message_verify_type(sd_bus_message *m, char type, const char *contents);
int sd_bus_message_at_end(sd_bus_message *m, int complete);
int sd_bus_message_rewind(sd_bus_message *m, int complete);

/* Bus management */

int sd_bus_get_unique_name(sd_bus *bus, const char **unique);
int sd_bus_request_name(sd_bus *bus, const char *name, uint64_t flags);
int sd_bus_release_name(sd_bus *bus, const char *name);
int sd_bus_list_names(sd_bus *bus, char ***acquired, char ***activatable); /* free the results */
int sd_bus_get_name_creds(sd_bus *bus, const char *name, uint64_t mask, sd_bus_creds **creds); /* unref the result! */
int sd_bus_get_name_machine_id(sd_bus *bus, const char *name, sd_id128_t *machine);

/* Convenience calls */

int sd_bus_call_method(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *ret_error, sd_bus_message **reply, const char *types, ...);
int sd_bus_get_property(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *ret_error, sd_bus_message **reply, const char *type);
int sd_bus_get_property_trivial(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *ret_error, char type, void *ret_ptr);
int sd_bus_get_property_string(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *ret_error, char **ret); /* free the result! */
int sd_bus_get_property_strv(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *ret_error, char ***ret); /* free the result! */
int sd_bus_set_property(sd_bus *bus, const char *destination, const char *path, const char *interface, const char *member, sd_bus_error *ret_error, const char *ret_type, ...);

int sd_bus_reply_method_return(sd_bus_message *call, const char *types, ...);
int sd_bus_reply_method_error(sd_bus_message *call, const sd_bus_error *e);
int sd_bus_reply_method_errorf(sd_bus_message *call, const char *name, const char *format, ...) _sd_printf_(3, 4);
int sd_bus_reply_method_errno(sd_bus_message *call, int error, const sd_bus_error *e);
int sd_bus_reply_method_errnof(sd_bus_message *call, int error, const char *format, ...) _sd_printf_(3, 4);

int sd_bus_emit_signal(sd_bus *bus, const char *path, const char *interface, const char *member, const char *types, ...);

int sd_bus_emit_properties_changed_strv(sd_bus *bus, const char *path, const char *interface, char **names);
int sd_bus_emit_properties_changed(sd_bus *bus, const char *path, const char *interface, const char *name, ...) _sd_sentinel_;

int sd_bus_emit_interfaces_added_strv(sd_bus *bus, const char *path, char **interfaces);
int sd_bus_emit_interfaces_added(sd_bus *bus, const char *path, const char *interface, ...) _sd_sentinel_;
int sd_bus_emit_interfaces_removed_strv(sd_bus *bus, const char *path, char **interfaces);
int sd_bus_emit_interfaces_removed(sd_bus *bus, const char *path, const char *interface, ...) _sd_sentinel_;

int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_bus_creds **creds);
int sd_bus_query_sender_privilege(sd_bus_message *call, int capability);

/* Credential handling */

int sd_bus_creds_new_from_pid(sd_bus_creds **ret, pid_t pid, uint64_t creds_mask);
sd_bus_creds *sd_bus_creds_ref(sd_bus_creds *c);
sd_bus_creds *sd_bus_creds_unref(sd_bus_creds *c);
uint64_t sd_bus_creds_get_mask(const sd_bus_creds *c);

int sd_bus_creds_get_pid(sd_bus_creds *c, pid_t *pid);
int sd_bus_creds_get_pid_starttime(sd_bus_creds *c, uint64_t *usec);
int sd_bus_creds_get_tid(sd_bus_creds *c, pid_t *tid);
int sd_bus_creds_get_uid(sd_bus_creds *c, uid_t *uid);
int sd_bus_creds_get_gid(sd_bus_creds *c, gid_t *gid);
int sd_bus_creds_get_comm(sd_bus_creds *c, const char **comm);
int sd_bus_creds_get_tid_comm(sd_bus_creds *c, const char **comm);
int sd_bus_creds_get_exe(sd_bus_creds *c, const char **exe);
int sd_bus_creds_get_cmdline(sd_bus_creds *c, char ***cmdline);
int sd_bus_creds_get_cgroup(sd_bus_creds *c, const char **cgroup);
int sd_bus_creds_get_unit(sd_bus_creds *c, const char **unit);
int sd_bus_creds_get_user_unit(sd_bus_creds *c, const char **unit);
int sd_bus_creds_get_slice(sd_bus_creds *c, const char **slice);
int sd_bus_creds_get_session(sd_bus_creds *c, const char **session);
int sd_bus_creds_get_owner_uid(sd_bus_creds *c, uid_t *uid);
int sd_bus_creds_has_effective_cap(sd_bus_creds *c, int capability);
int sd_bus_creds_has_permitted_cap(sd_bus_creds *c, int capability);
int sd_bus_creds_has_inheritable_cap(sd_bus_creds *c, int capability);
int sd_bus_creds_has_bounding_cap(sd_bus_creds *c, int capability);
int sd_bus_creds_get_selinux_context(sd_bus_creds *c, const char **context);
int sd_bus_creds_get_audit_session_id(sd_bus_creds *c, uint32_t *sessionid);
int sd_bus_creds_get_audit_login_uid(sd_bus_creds *c, uid_t *loginuid);
int sd_bus_creds_get_unique_name(sd_bus_creds *c, const char **name);
int sd_bus_creds_get_well_known_names(sd_bus_creds *c, char ***names);
int sd_bus_creds_get_description(sd_bus_creds *c, const char **name);

/* Error structures */

struct sd_bus_name_error_mapping {
        const char* name;
        int code;
};
typedef struct sd_bus_name_error_mapping sd_bus_name_error_mapping;

#define SD_BUS_ERROR_MAKE_CONST(name, message) ((const sd_bus_error) {(name), (message), 0})
#define SD_BUS_ERROR_NULL SD_BUS_ERROR_MAKE_CONST(NULL, NULL)

#ifndef SD_BUS_ERROR_MAPPING
#  define _SD_BUS_ERROR_XCONCAT(x, y) x ## y
#  define _SD_BUS_ERROR_CONCAT(x, y) _SD_BUS_ERROR_XCONCAT(x, y)
#  define SD_BUS_ERROR_MAPPING(name)                                    \
        __attribute((__section__("sd_bus_errnomap")))                   \
        __attribute((__used__))                                         \
        const sd_bus_name_error_mapping _SD_BUS_ERROR_CONCAT(_sd_bus_errno_mapping_, name)[]
#  define SD_BUS_ERROR_MAPPING_USE(name)                                \
        extern                                                          \
        const sd_bus_name_error_mapping _SD_BUS_ERROR_CONCAT(_sd_bus_errno_mapping_, name)[]; \
        __attribute((__used__))                                         \
        static const sd_bus_name_error_mapping*                         \
        _SD_BUS_ERROR_CONCAT(sd_bus_name_error_mapping_ref, __COUNTER__) \
        = _SD_BUS_ERROR_CONCAT(_sd_bus_errno_mapping_, name);
#endif


void sd_bus_error_free(sd_bus_error *e);
int sd_bus_error_set(sd_bus_error *e, const char *name, const char *message);
int sd_bus_error_setf(sd_bus_error *e, const char *name, const char *format, ...)  _sd_printf_(3, 4);
int sd_bus_error_set_const(sd_bus_error *e, const char *name, const char *message);
int sd_bus_error_set_errno(sd_bus_error *e, int error);
int sd_bus_error_set_errnof(sd_bus_error *e, int error, const char *format, ...) _sd_printf_(3, 4);
int sd_bus_error_get_errno(const sd_bus_error *e);
int sd_bus_error_copy(sd_bus_error *dest, const sd_bus_error *e);
int sd_bus_error_is_set(const sd_bus_error *e);
int sd_bus_error_has_name(const sd_bus_error *e, const char *name);

/* Auxiliary macros */

#define SD_BUS_MESSAGE_APPEND_ID128(x) 16,                              \
                (x).bytes[0],  (x).bytes[1],  (x).bytes[2],  (x).bytes[3], \
                (x).bytes[4],  (x).bytes[5],  (x).bytes[6],  (x).bytes[7], \
                (x).bytes[8],  (x).bytes[9],  (x).bytes[10], (x).bytes[11], \
                (x).bytes[12], (x).bytes[13], (x).bytes[14], (x).bytes[15]

#define SD_BUS_MESSAGE_READ_ID128(x) 16,                                \
                &(x).bytes[0],  &(x).bytes[1],  &(x).bytes[2],  &(x).bytes[3], \
                &(x).bytes[4],  &(x).bytes[5],  &(x).bytes[6],  &(x).bytes[7], \
                &(x).bytes[8],  &(x).bytes[9],  &(x).bytes[10], &(x).bytes[11], \
                &(x).bytes[12], &(x).bytes[13], &(x).bytes[14], &(x).bytes[15]

/* Label escaping */

int sd_bus_path_encode(const char *prefix, const char *external_id, char **ret_path);
int sd_bus_path_decode(const char *path, const char *prefix, char **ret_external_id);

/* Tracking peers */

int sd_bus_track_new(sd_bus *bus, sd_bus_track **track, sd_bus_track_handler_t handler, void *userdata);
sd_bus_track* sd_bus_track_ref(sd_bus_track *track);
sd_bus_track* sd_bus_track_unref(sd_bus_track *track);

sd_bus* sd_bus_track_get_bus(sd_bus_track *track);
void *sd_bus_track_get_userdata(sd_bus_track *track);
void *sd_bus_track_set_userdata(sd_bus_track *track, void *userdata);

int sd_bus_track_add_sender(sd_bus_track *track, sd_bus_message *m);
int sd_bus_track_remove_sender(sd_bus_track *track, sd_bus_message *m);
int sd_bus_track_add_name(sd_bus_track *track, const char *name);
int sd_bus_track_remove_name(sd_bus_track *track, const char *name);

unsigned sd_bus_track_count(sd_bus_track *track);
const char* sd_bus_track_contains(sd_bus_track *track, const char *names);
const char* sd_bus_track_first(sd_bus_track *track);
const char* sd_bus_track_next(sd_bus_track *track);

_SD_END_DECLARATIONS;

#endif