STREAMS Modules connld(7M)
NAME
connld - line discipline for unique stream connections
SYNOPSIS
#include
int ioctl(fd,I_PUSH,"connld");
DESCRIPTION
connld is a STREAMS-based module that provides unique con-
nections between server and client processes. It can only bepushed (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 fattach(3C). After the pipe end isattached, a new pipe is created internally when an ori-
ginating 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 ioctlI_SENDFD (see streamio(7I)) and is transmitted along the
stream to the server process on the other end. The ori-
ginating 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 retrieveany data off the stream until the I_RECVFD request is
issued. If the server process exits before issuing theI_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.SunOS 5.11 Last change: 3 May 2004 1
STREAMS Modules connld(7M)
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 GuideSunOS 5.11 Last change: 3 May 2004 2