sd_bus_set_address, sd_bus_get_address, sd_bus_set_exec — Set or query the address of the bus connection
#include <systemd/sd-bus.h>
int sd_bus_set_address( | sd_bus *bus, |
const char *address); |
int sd_bus_get_address( | sd_bus *bus, |
const char **address); |
int sd_bus_set_exec( | sd_bus *bus, |
| const char *path, | |
char *const *argv); |
sd_bus_set_address() configures a list of addresses of bus brokers to try to
connect to from a subsequent
sd_bus_start(3) call.
The argument is a ";"-separated list of addresses to try. Each item must be one of the
following:
A unix socket address specified as
"unix:guid=" or
"guid,path=pathunix:guid=".
Exactly one of the guid,abstract=pathpath= and abstract= keys must be present,
while guid= is optional.
A TCP socket address specified as
"tcp:[guid=".
One or both of the guid,][host=host][,port=port][,family=family]host= and port= keys must be present, while
the rest is optional. family may be either ipv4 or
ipv6.
An executable to spawn specified as
"unixexec:guid=".
The guid,path=path,argv1=argument,argv2=argument,...path= key must be present, while guid= is optional.
A machine (container) to connect to specified as
"x-machine-unix:guid=".
Exactly one of the guid,machine=machine,pid=pidmachine= and pid= keys must be present,
while guid= is optional. machine is the name of a local
container. See
machinectl(1) for
more information about the "machine" concept. "machine=.host" may be used to specify
the host machine. A connection to the standard system bus socket inside of the specified machine will
be created.
In all cases, parameter guid is an identifier of the remote peer, in the
syntax accepted by
sd_id128_from_string(3).
If specified, the identifier returned by the peer after the connection is established will be checked and
the connection will be rejected in case of a mismatch.
Note that the addresses passed to sd_bus_set_address() may not be verified
immediately. If they are invalid, an error may be returned e.g. from a subsequent call to
sd_bus_start(3).
sd_bus_get_address() returns any previously set addresses. In addition to
being explicitly set by sd_bus_set_address(), the address will also be set
automatically by
sd_bus_open(3) and
similar calls, based on environment variables or built-in defaults.
sd_bus_set_exec() is a shorthand function for setting a
"unixexec" address that spawns the given executable with the given arguments.
If argv is NULL, the given executable is spawned
without any extra arguments.
On success, these functions return a non-negative integer. On failure, they return a negative errno-style error code.
Returned errors may indicate the following problems:
-EINVAL¶The input parameters bus or address are NULL.
-ENOPKG¶The bus object bus could not be resolved.
-EPERM¶The input parameter bus is in a wrong state
(sd_bus_set_address() may only be called once on a newly-created bus object).
-ECHILD¶The bus object bus was created in a different
process.
-ENODATA¶The bus object bus has no address configured.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
libsystemd pkg-config(1)
file.
The code described here uses
getenv(3),
which is declared to be not multi-thread-safe. This means that the code calling the functions described
here must not call
setenv(3)
from a parallel thread. It is recommended to only do calls to setenv()
from an early phase of the program when no other threads have been started.
sd_bus_set_address(),
sd_bus_get_address(), and
sd_bus_set_exec() were added in version 246.