IEEE80211_NODE(9) OpenBSD Kernel Manual IEEE80211_NODE(9)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);
struct ieee80211_node *
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 ALSOieee80211(9)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>.
OpenBSD 4.9 December 15, 2009 OpenBSD 4.9