Get the default selinux security context for the specified mediatype from the policy
#include <selinux/selinux.h>
int matchmediacon(const char *media, char **con);
matchmediacon() matches the specified media type with the media contexts configuration and sets the security context con to refer to the resulting context.
Note: Caller must free returned security context con using freecon(3).
Returns 0 on success or -1 otherwise.
/etc/selinux/{POLICYTYPE}/contexts/files/media