NAME
ieee80211_node_attach
,
ieee80211_node_lateattach
,
ieee80211_node_detach
,
ieee80211_begin_scan
,
ieee80211_next_scan
,
ieee80211_create_ibss
,
ieee80211_end_scan
,
ieee80211_alloc_node
,
ieee80211_dup_bss
,
ieee80211_find_node
,
ieee80211_release_node
,
ieee80211_free_node
,
ieee80211_free_allnodes
,
ieee80211_iterate_nodes
—
software 802.11 stack node management
functions
SYNOPSIS
#include
<net80211/ieee80211_var.h>
#include
<net80211/ieee80211_proto.h>
#include
<net80211/ieee80211_node.h>
void
ieee80211_node_attach
(struct
ifnet *ifp);
void
ieee80211_node_lateattach
(struct
ifnet *ifp);
void
ieee80211_node_detach
(struct
ifnet *ifp);
void
ieee80211_begin_scan
(struct
ifnet *ifp);
void
ieee80211_next_scan
(struct
ifnet *ifp);
void
ieee80211_create_ibss
(struct
ieee80211com *ic, struct ieee80211_channel
*chan);
void
ieee80211_end_scan
(struct
ifnet *ifp);
struct ieee80211_node *
ieee80211_alloc_node
(struct
ieee80211com *ic, const
u_int8_t *macaddr);
struct ieee80211_node *
ieee80211_dup_bss
(struct
ieee80211com *ic, const
u_int8_t *macaddr);
struct ieee80211_node *
ieee80211_find_node
(struct
ieee80211com *ic, const
u_int8_t *macaddr);
void
ieee80211_release_node
(struct
ieee80211com *ic, struct
ieee80211_node *ni);
void
ieee80211_free_node
(struct
ieee80211com *ic, struct
ieee80211_node *ni);
void
ieee80211_free_allnodes
(struct
ieee80211com *ic);
void
ieee80211_iterate_nodes
(struct
ieee80211com *ic, ieee80211_iter_func *f,
void *arg);
DESCRIPTION
These functions are used to manage node lists within the software 802.11 stack. These lists are typically used for implementing host-mode AP functionality, or providing signal quality information about neighbouring nodes.
The
ieee80211_node_attach
()
function is called from
ieee80211_ifattach(9) to initialize node database management
callbacks for the interface ifp (specifically for
memory allocation, node copying and node signal inspection). These functions
may be overridden in special circumstances, as long as this is done after
calling
ieee80211_ifattach(9) and prior to any other call which may
allocate a node.
The
ieee80211_node_lateattach
()
function initialises the ic_bss node element of the
interface ifp during
ieee80211_media_init(9). This late attachment is to account
for certain special cases described under
ieee80211_node_attach
().
The
ieee80211_node_detach
()
function destroys all node database state associated with the interface
ifp, and is usually called during device detach.
The
ieee80211_begin_scan
()
function initialises the node database in preparation of an active scan for
an access point on the interface ifp. The scan begins
on the next radio channel by calling
ieee80211_next_scan
() internally. The actual
scanning for an access point is not automated; the device driver itself only
handles setting the radio frequency of the card and stepping through the
channels.
The
ieee80211_next_scan
()
function is used to inform the
ieee80211(9) layer that the interface ifp is
now scanning for an access point on the next radio channel. A device driver
is expected to first call ieee80211_begin_scan
(), to
initialize the node database, then set the radio channel on the device;
then, after a certain time has elapsed (200ms for example), call
ieee80211_next_scan
() to move to the next channel.
Typically, a timeout is used to automate this process; see
timeout(9) for more information on how to use timeouts.
The
ieee80211_create_ibss
()
function sets up the net80211-specific portion of an interface's softc,
ic, for use in IBSS mode.
The
ieee80211_end_scan
()
function is called by ieee80211_next_scan
() when the
state machine has performed a full cycle of scanning on all available radio
channels. Internally, ieee80211_end_scan
() will
inspect the node cache associated with the interface
ifp for suitable access points found during scanning,
and associate with one, should the parameters of the node match those of the
configuration requested from userland.
The
ieee80211_alloc_node
()
function allocates an instance of struct
ieee80211_node for a node having the MAC address
macaddr, and associates it with the interface
ic. If the allocation is successful, the node
structure is initialised by
ieee80211_setup_node
();
otherwise, NULL
is returned.
The
ieee80211_dup_bss
()
function is similar to ieee80211_alloc_node
(), but
is instead used to create a node database entry for the BSSID
macaddr associated with the interface
ic. If the allocation is successful, the node
structure is initialised by ieee80211_setup_node
();
otherwise, NULL
is returned.
The
ieee80211_find_node
()
function will iterate through the node list associated with the interface
ic, searching for a node entry which matches
macaddr. If the entry is found, its reference count is
incremented, and a pointer to the node is returned; otherwise,
NULL
will be returned.
The
ieee80211_free_node
()
function will remove the node ni from the node
database entries associated with the interface ic, and
free any memory associated with the node. This private method can be
overridden in ieee80211_node_attach
().
The
ieee80211_free_allnodes
()
function will iterate through the node list calling
ieee80211_free_node
() for all nodes associated with
the interface ic.
The
ieee80211_iterate_nodes
()
function will call the user-defined callback function
f for all nodes in the node database associated with
the interface ic. The callback is invoked with the
with the user-supplied value arg and a pointer to the
current node.
SEE ALSO
HISTORY
The ieee80211
series of functions first
appeared in NetBSD 1.5, and were later ported to
FreeBSD 4.6 and OpenBSD
3.6.
AUTHORS
This man page was written by Bruce M. Simpson <bms@FreeBSD.org> and Darron Broad <darron@kewl.org>.