NAME

       sd_machine_get_class, sd_machine_get_ifindices - Determine the class and network interface
       indices of a locally running virtual machine or container

SYNOPSIS

       #include <systemd/sd-login.h>

       int sd_machine_get_class(const char* machine, char **class);

       int sd_machine_get_ifindices(const char* machine, int **ret_ifindices);

DESCRIPTION

       sd_machine_get_class() may be used to determine the class of a locally running virtual
       machine or container that is registered with systemd-machined.service(8). The string
       returned is either "vm" or "container". The returned string needs to be freed with the
       libc free(3) call after use.

       sd_machine_get_ifindices() may be used to determine the numeric indices of the network
       interfaces on the host that are pointing towards the specified locally running virtual
       machine or container. The vm or container must be registered with systemd-
       machined.service(8). The output parameter ret_ifindices may be passed as NULL when the
       output value is not needed. The returned array needs to be freed with the libc free(3)
       call after use.

RETURN VALUE

       On success, these functions return a non-negative integer.  sd_machine_get_ifindices()
       returns the number of the relevant network interfaces. On failure, these calls return a
       negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

       -ENXIO
           The specified machine does not exist or is currently not running.

       -EINVAL
           An input parameter was invalid (out of range, or NULL, where that is not accepted).

       -ENOMEM
           Memory allocation failed.

NOTES

       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.

HISTORY

       sd_machine_get_class() and sd_machine_get_ifindices() were added in version 217.

SEE ALSO

       systemd(1), sd-login(3), systemd-machined.service(8), sd_pid_get_machine_name(3)