CONNLD(7M)CONNLD(7M)NAMEconnld - line discipline for unique stream connections
SYNOPSIS
#include </sys/steam.h>
int ioctl(fd,I_PUSH,"connld");
DESCRIPTIONconnld 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 subse‐
quently 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 inter‐
nally 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 trans‐
mitted 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 ALSOcreat(2), open(2), fattach(3C), streamio(7I)
STREAMS Programming Guide
May 3, 2004 CONNLD(7M)
