.\"	$OpenBSD: ieee80211_output.9,v 1.6 2015/11/23 17:53:57 jmc Exp $
.\"
.\" Copyright (c) 2004 Bruce M. Simpson <bms@spc.org>
.\" Copyright (c) 2004 Darron Broad <darron@kewl.org>
.\" All rights reserved.
.\"
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.\" $FreeBSD: src/share/man/man9/ieee80211_output.9,v 1.2 2004/07/07 12:59:39 ru Exp $
.\" $Id: ieee80211_output.9,v 1.6 2015/11/23 17:53:57 jmc Exp $
.\"
.Dd $Mdocdate: November 23 2015 $
.Dt IEEE80211_ENCAP 9
.Os
.Sh NAME
.Nm ieee80211_encap , ieee80211_add_rates ,
.Nm ieee80211_add_xrates ,
.Nm ieee80211_send_mgmt
.Nd software 802.11 stack output functions
.Sh SYNOPSIS
.In net80211/ieee80211_var.h
.In net80211/ieee80211_proto.h
.Ft struct mbuf *
.Fo ieee80211_encap
.Fa "struct ifnet *ifp" "struct mbuf *m" "struct ieee80211_node **pni"
.Fc
.Ft u_int8_t *
.Fn ieee80211_add_rates "u_int8_t *frm" "const struct ieee80211_rateset *rs"
.Ft u_int8_t *
.Fn ieee80211_add_xrates "u_int8_t *frm" "const struct ieee80211_rateset *rs"
.Ft int
.Fo ieee80211_send_mgmt
.Fa "struct ieee80211com *ic" "struct ieee80211_node *ni" "int type" "int arg"
.Fc
.Sh DESCRIPTION
These functions handle the encapsulation and transmission of 802.11 frames
within the software 802.11 stack.
.Pp
The
.Fn ieee80211_encap
function encapsulates an outbound data frame contained within the
mbuf chain
.Fa m
from the interface
.Fa ifp .
The argument
.Fa *pni
is a reference to the destination node.
.Pp
If the function is successful, the mbuf chain is updated with the
802.11 frame header prepended, and a pointer to the head of the chain
is returned.
If an error occurs,
.Dv NULL
will be returned, and
.Fa *pni
is also set to
.Dv NULL .
The caller is responsible for freeing the node reference if
.Fa *pni
is
.Pf non- Dv NULL
on return.
The convention is that
.Va ic_bss
is not reference counted; the caller is responsible for maintaining this
reference count.
.Pp
.\"
The
.Fn ieee80211_add_rates
utility function is used to add the rate set element
.Fa *rs
to the frame
.Fa frm .
A pointer to the location in the buffer after the addition of the rate set
is returned.
It is typically used when constructing management frames from within the
software 802.11 stack.
.Pp
.\"
The
.Fn ieee80211_add_xrates
utility function is used to add the extended rate set element
.Fa *rs
to the frame
.Fa frm .
A pointer to the location in the buffer after the addition of the rate set
is returned.
It is typically used when constructing management frames from within the
software 802.11 stack in 802.11g mode.
.Pp
.\"
The
.Fn ieee80211_send_mgmt
function transmits a management frame on the interface
.Fa ic
to the destination node
.Fa ni
of type
.Fa type .
.Pp
The argument
.Fa arg
specifies either a sequence number for authentication operations,
a status code for [re]association operations,
or a reason for deauthentication and deassociation operations.
.Pp
Nodes other than
.Va ic_bss
have their reference count incremented to reflect their use for an
indeterminate amount of time.
This reference is freed when the function returns.
.Pp
The function returns 0 if successful; if temporary buffer space is not
available, the function returns
.Er ENOMEM .
.\"
.Sh SEE ALSO
.Xr ieee80211 9
.Sh HISTORY
The
.Nm ieee80211
series of functions first appeared in
.Nx 1.5 ,
and were later ported to
.Fx 4.6
and
.Ox 3.6 .
.Sh AUTHORS
.An -nosplit
This man page was written by
.An Bruce M. Simpson Aq Mt bms@FreeBSD.org
and
.An Darron Broad Aq Mt darron@kewl.org .