/// @brief Simulate opening of the socket.
///
- /// This function simulates opening a primary socket. In reality, it doesn't
- /// open a socket but the socket descriptor returned in the SocketInfo
- /// structure is always set to 0.
+ /// This function simulates opening a primary socket. Rather than open
+ /// an actual socket, the stub peforms a read-only open of "/dev/null".
+ /// The fd returned by this open saved as the socket's descriptor in the
+ /// SocketInfo structure. This way the filter consumes an actual
+ /// descriptor and retains it until its socket is closed.
///
/// @param iface An interface descriptor.
/// @param addr Address on the interface to be used to send packets.