TCP Urgent Support
843790Jun 17 2006 — edited Jun 19 2006I am implementing an NVT in accordance with RFC 854 to handle communications for an FTP server protocol interpreter. As such, I require the use of the telnet "synch" mechanism which relies upon my ability to recognize that the client has entered urgent mode. The following note appears in the J2SE 5 API documentation within the description of the setOOBInline method of the Socket class:
Note, only limited support is provided for handling incoming urgent data. In particular, no notification of incoming urgent data is provided and there is no capability to distinguish between normal data and urgent data unless provided by a higher level protocol.
I believe that I may be able to work around this issue simply by ignoring the section of RFC 854 that dictates that I must discard any data other than the specified "interesting signals" because of the way that FTP uses its control connection, but I'm not sure.
Can anyone provide some insight into either a workaround that allows me to somehow coax urgent data notifications out of a connection or confirmation that ignoring this issue and moving ahead will enable me to produce a (non-compliant!!) functional system?
Any assistance is greatly appreciated!
- Kyle W. Cartmell