Comment 1 for bug 1213196

In addition to allowing low DTR to drop the socket connection, and allowing low DTR to reject a socket connection, the DCD modem bit also be implemented - DCD should follow the state of the TCP socket: a connected socket should pull DCD high, and a disconnected socket should pull DCD low. From what Ive seen in the source, it looks like a serial IOCTL functioned needs to be added to chardev/char-socket.c to allow the MSR bits to be tracked against the state of the socket. DCD should be very easy to implement this way, but I hadn't thought about DTR.