.\" Copyright (C) 2025 Jens Axboe <axboe@kernel.dk>
.\"
.\" SPDX-License-Identifier: LGPL-2.0-or-later
.\"
.TH io_uring_register_ifq 3 "January 18, 2025" "liburing-2.10" "liburing Manual"
.SH NAME
io_uring_register_ifq \- register a zero-copy receive interface queue
.SH SYNOPSIS
.nf
.B #include <liburing.h>
.PP
.BI "int io_uring_register_ifq(struct io_uring *" ring ","
.BI "                          struct io_uring_zcrx_ifq_reg *" reg ");"
.fi
.SH DESCRIPTION
.PP
The
.BR io_uring_register_ifq (3)
function registers a zero-copy receive interface queue with the io_uring
instance specified by
.IR ring .
Zero-copy receive allows the kernel to place incoming network data directly
into application-provided memory without copying.

The
.I reg
argument is a pointer to a
.I struct io_uring_zcrx_ifq_reg
that describes the interface queue to register. See
.BR io_uring_register (2)
for a description of the
.B IORING_REGISTER_ZCRX_IFQ
operation and the structure fields.

The io_uring ring must have been created with
.B IORING_SETUP_DEFER_TASKRUN
and either
.B IORING_SETUP_CQE32
or
.B IORING_SETUP_CQE_MIXED
flags set. The caller must have the
.B CAP_NET_ADMIN
capability.

.SH RETURN VALUE
Returns 0 on success. On error, a negative errno value is returned.
.SH SEE ALSO
.BR io_uring_register (2),
.BR io_uring_setup (2)