mirror of
https://github.com/freebsd/freebsd-src
synced 2024-07-22 02:37:15 +00:00
79 lines
2.7 KiB
Groff
79 lines
2.7 KiB
Groff
.\"
|
|
.\" SPDX-License-Identifier: BSD-2-Clause
|
|
.\"
|
|
.\" Copyright (C) 2021 Kyle Evans <kevans@FreeBSD.org>
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice(s), this list of conditions and the following disclaimer as
|
|
.\" the first lines of this file unmodified other than the possible
|
|
.\" addition of one or more copyright notices.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice(s), this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
|
|
.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
|
|
.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
|
|
.\" DAMAGE.
|
|
.\"
|
|
.Dd June 1, 2021
|
|
.Dt ETHER_GEN_ADDR 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ether_gen_addr
|
|
.Nd "generate an arbitrary MAC address for use"
|
|
.Sh SYNOPSIS
|
|
.In sys/types.h
|
|
.In sys/socket.h
|
|
.In net/if.h
|
|
.In net/if_var.h
|
|
.In net/ethernet.h
|
|
.Ft void
|
|
.Fn ether_gen_addr "struct ifnet *ifp" "struct ether_addr *hwaddr"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn ether_gen_addr
|
|
function generates an arbitrary MAC address for use by an ethernet interface
|
|
that does not have an assigned address.
|
|
.Pp
|
|
By default,
|
|
.Nm
|
|
attempts to generate a stable MAC address using the hostid of the jail that
|
|
the
|
|
.Ar ifp
|
|
is being added to.
|
|
During early boot, the hostid may not be set on machines that haven't yet
|
|
populated
|
|
.Pa /etc/hostid ,
|
|
or on machines that do not use
|
|
.Xr loader 8 .
|
|
.Pp
|
|
.Nm
|
|
can fail to derive a MAC address due to memory allocation failure, or because
|
|
the hostid has not been populated.
|
|
In these cases, a locally-administered unicast MAC address will be randomly
|
|
generated and returned via the
|
|
.Ar hwaddr
|
|
parameter.
|
|
.Pp
|
|
If
|
|
.Nm
|
|
succeeds, then it will return a MAC address in the FreeBSD Foundation OUI,
|
|
.Dq 58:9c:fc ,
|
|
via the
|
|
.Ar hwaddr
|
|
parameter.
|
|
.Sh AUTHORS
|
|
This manual page was written by
|
|
.An Kyle Evans Aq Mt kevans@FreeBSD.org .
|