.\" Ouroboros man pages CC-BY 2017 - 2020
.\" Dimitri Staessens <dimitri.staessens@ugent.be>
.\" Sander Vrijders <sander.vrijders@ugent.be>

.TH FCCNTL 3 2018-10-04 Ouroboros "Ouroboros Programmer's Manual"

.SH NAME

fccntl \- control commands for flows and FRCT connections

.SH SYNOPSIS

.B #include <ouroboros/fccntl.h>

\fBint fccntl(int \fIfd\fB, int \fIcmd\fB, ...);

Compile and link with \fI-louroboros-dev\fR.

.SH DESCRIPTION

\fBfccntl\fR() is used to control the configuration of flows and
connections.

Supported commands are:

\fBFLOWSSNDTIMEO\fR - set the sender timeout. Takes a \fBstruct
timespec * \fItimeo\fR as third argument. Passing NULL for \fItimeo\fR
disables the timeout.

\fBFLOWGSNDTIMEO\fR - retrieve the current sender timeout. Takes a
\fBstruct timespec * \fItimeo\fR as third argument.

\fBFLOWSRCVTIMEO\fR - set the receiver timeout. Takes a \fBstruct
timespec * \fItimeo\fR as third argument. Passing NULL for \fItimeo\fR
disables the timeout.

\fBFLOWGRCVTIMEO\fR - retrieve the current receiver timeout. Takes a
\fBstruct timespec * \fItimeo\fR as third argument.

\fBFLOWGQOSSPEC\fR  - retrieve the current QoS specification of the
flow. Takes a \fBqosspec_t * \fIqs\fR as third argument.

\fBFLOWSFLAGS\fR    - set flow flags. Takes flow flags as third
argument. Supported flags are:

.RS 8
\fIFLOWFRDONLY\fR   - set flow to read-only.

\fIFLOWFWRONLY\fR   - set flow_to write-only.

\fIFLOWFRDWR\fR     - set flow to read-write.

\fIFLOWFDOWN\fR     - mark flow as down.

\fIFLOWFRNOBLOCK\fR - set read to non-blocking.

\fIFLOWFWNOBLOCK\fR - set write to non-blocking.

\fIFLOWFNONBLOCK\fR - set I/O to non-blocking read/write.

\fIFLOWFRNOPART\fR  - disable partial reading.

\fIFLOWFWNOPART\fR  - disable partial writing.

\fIFLOWFDEFAULT\fR  - set flow defaults (blocking, read-write,
no partial writes).

.RE

\fBFLOWGFLAGS\fR    - get the current flow flags. Takes an \fBuint32_t
\fIflags\fR as third argument.

\fBFLOWGRXQLEN\fR   - get the current number of packets in the receive
buffer. Takes a \fBsize_t \fIqlen\fR as third argument.

\fBFLOWGTXQLEN\fR   - get the current number of packets in the transmit
buffer. Takes a \fBsize_t \fIqlen\fR as third argument.

\fBFRCTGFLAGS\fR    - get the current flow flags. Takes an \fBuint16_t
\fIflags\fR as third argument. Supported flags are:

.RS 8
\fIFRCTFRESCNTRL\fR - resource control enabled.

\fIFRCTFRTX\fR      - retransmission enabled.

.RE


.SH RETURN VALUE

On success, \fBfccntl\fR() returns 0.

.SH ERRORS

\fBfccntl\fR() can return

.B -EINVAL
An invalid argument was passed.

.B -EPERM
Operation not permitted. This is returned when requesting the value of
a timeout (FLOWGSNDTIMEO or FLOWGRCVTIMEO) when no such timeout was
set.

.B -EBADF
Invalid flow descriptor passed.

.B -ENOTALLOC
Flow is not allocated.

.B -ENOTSUP
The specified command is not supported.

.SH ATTRIBUTES

For an explanation of the terms used in this section, see \fBattributes\fR(7).

.TS
box, tab(&);
LB|LB|LB
L|L|L.
Interface & Attribute & Value
_
\fBfccntl\fR() & Thread safety & MT-Safe
.TE

.SH TERMINOLOGY
Please see \fBouroboros-glossary\fR(7).

.SH SEE ALSO

.BR flow_alloc "(3), " flow_read "(3), " fqueue "(3), " fset "(3), " \
ouroboros (8)

.SH COLOPHON
This page is part of the Ouroboros project, found at
http://ouroboros.rocks

These man pages are licensed under the Creative Commons Attribution
4.0 International License. To view a copy of this license, visit
http://creativecommons.org/licenses/by/4.0/