connld(7M)							  STREAMS Modules							connld(7M)

NAME

       connld - line discipline for unique stream connections

SYNOPSIS

       #include </sys/steam.h>

       int ioctl(fd,I_PUSH,"connld");

DESCRIPTION

       connld  is  a  STREAMS-based  module  that  provides  unique  connections  between  server and client processes. It can only be pushed (see
       streamio(7I)) onto one end of a STREAMS-based pipe that may subsequently be attached to a name in the file system  name	space  with   fat-
       tach(3C).  After  the pipe end is attached, a new pipe is created internally when an  originating process attempts to  open(2) or  creat(2)
       the file system name. A file descriptor for one end of the new pipe is packaged into a message identical to that for  the  ioctl   I_SENDFD
       (see   streamio(7I))  and is transmitted along the stream to the server process on the  other end. The originating process is blocked until
       the server responds.

       The server responds to the  I_SENDFD request by accepting the file descriptor through the  I_RECVFD ioctl message. When this  happens,  the
       file  descriptor  associated  with  the other end of the new pipe is transmitted to the originating process as the file descriptor returned
       from open(2) or creat(2).

       If the server does not respond to the  I_SENDFD request, the stream that the connld module is pushed on becomes uni-directional because the
       server	will  not  be  able  to retrieve any data off the stream until the  I_RECVFD request is issued. If the server process exits before
       issuing the  I_RECVFD request, the open(2) or the creat(2) invocation will fail and return -1 to the originating process.

       When the connld module is pushed onto a pipe, it ignores messages going back and forth  through the pipe.

ERRORS

       On success, an open of connld returns 0. On failure, errno is set to the following values:

       EINVAL	  A stream onto which connld is being pushed is not a pipe or the pipe does not have a write queue pointer pointing  to  a  stream
		  head read queue.

       EINVAL	  The other end of the pipe onto which connld is being pushed is linked under a multiplexor.

       EPIPE	  connld is being pushed onto a pipe end whose other end is no longer there.

       ENOMEM	  An internal pipe could not be created.

       ENXIO	  An  M_HANGUP message is at the stream head of the pipe onto which connld is being pushed.

       EAGAIN	  Internal data structures could not be allocated.

       ENFILE	  A file table entry could not be allocated.

SEE ALSO

       creat(2), open(2), fattach(3C), streamio(7I)

       STREAMS Programming Guide

SunOS 5.11							    3 May 2004								connld(7M)