12.5.1 In-Band Data

Calling recv with flags set to zero reads in-band data. Normally, each recv returns one complete X.25 message. It is very important to note that if the size of the receive buffer is not sufficient to hold the entire X.25 message, the excess is discarded and no error indication is returned. This is a feature of SunOS sockets, not of Solstice X.25. count returns a count of the number of bytes returned by recv. If the user wishes to read an X.25 message in pieces smaller than a complete message, the X25_RECORD_SIZE ioctl should be used as described in the section "12.5.3 Receiving X.25 Messages in Records "of this chapter.

Unless non-blocking I/O has been requested, the recv call will block unless there is some data that can be returned to the user. If the connection is cleared (due to normal or abnormal reasons) while recv is blocked, recv will return a count of zero. A return value of zero from recv is an indication that the connection has been cleared, and the user must close the socket at this point.