1 # dt_fd_forward 2 3 dt_fd_forward is a jdwpTransport library. It implements the [Java Debug Wire 4 Protocol Transport Interface 5 (jdwpTransport)](https://docs.oracle.com/javase/7/docs/technotes/guides/jpda/jdwpTransport.html). 6 It allows one to handle and proxy JDWP traffic by supplying the implementation 7 for Attach. This transport requires an address. The address is a single integer 8 value that is the file-descriptor of an open AF\_UNIX socket. 9 10 When this transport begins listening or attaching it will send the 11 null-terminated string "dt_fd_forward:START-LISTEN\0" over the given socket. 12 13 When this transport stops listening for connections it will send the 14 null-terminated string "dt_fd_forward:END-LISTEN\0" over the socket. 15 16 When this transport has successfully received fds from the proxy it sends the 17 message "dt_fd_forward:ATTACHED\0" over the socket. 18 19 When this transport has closed its copies of the fds it will send the proxy the 20 message "dt_fd_forward:CLOSING\0" over the socket. 21 22 When this transport accepts or attaches to a connection it will read from the 23 socket a 1 byte message and 3 file-descriptors. The file descriptors are, in 24 order, an fd that will be read from to get incoming JDWP packets (read\_fd\_), 25 an fd that outgoing JDWP packets will be written to (write\_fd\_), and an 26 _eventfd_ (write\_lock\_fd\_). The eventfd should not have any flags set. Prior 27 to writing any data to write\_fd\_ the transport will _read_ from the 28 write\_lock\_fd\_ and after finishing the write it will _write_ to it. This 29 allows one to safely multiplex data on the write\_fd\_. 30 31 This transport implements no optional capabilities, though this may change in 32 the future. 33
