IEEE80211_NODE(9) | Kernel Developer's Manual | IEEE80211_NODE(9)

# NAME

ieee80211_node_attach, ieee80211_node_lateattach, ieee80211_node_detach, ieee80211_begin_scan, ieee80211_next_scan, ieee80211_end_scan, ieee80211_create_ibss, ieee80211_alloc_node, ieee80211_dup_bss, ieee80211_find_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 ieee80211com *ic);

void
ieee80211_node_lateattach(struct ieee80211com *ic);

void
ieee80211_node_detach(struct ieee80211com *ic);

void
ieee80211_begin_scan(struct ieee80211com *ic, int reset);

void
ieee80211_next_scan(struct ieee80211com *ic);

void
ieee80211_end_scan(struct ieee80211com *ic);

void
ieee80211_create_ibss(struct ieee80211com *ic, struct ieee80211_channel *chan);

struct ieee80211_node *
ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr);

struct ieee80211_node *
ieee80211_dup_bss(struct ieee80211_node_table *nt, const u_int8_t *macaddr);

struct ieee80211_node *
ieee80211_find_node(struct ieee80211_node_table *nt, const u_int8_t *macaddr);

void
ieee80211_free_node(struct ieee80211_node *ni);

void
ieee80211_free_allnodes(struct ieee80211_node_table *nt);

void
ieee80211_iterate_nodes(struct ieee80211_node_table *nt, 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 ic (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 ic 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 ic, and is usually called during device detach.

The ieee80211_begin_scan() function initialises the node database in preparation of a scan for an access point on the interface ic and begins the scan. The parameter reset controls if a previously built node list should be cleared. The actual scanning for an access point is not fully automated: the device driver itself controls stepping through the channels, usually by a periodical callback.

The ieee80211_next_scan() function is used to inform the ieee80211(9) layer that the next channel for interface ic should be scanned.

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 peformed a full cycle of scanning on all available radio channels. Internally, ieee80211_end_scan() will inspect the node cache associated with the interface ic for suitable access points found during scanning, and associate with one, should the parameters of the node match those of the configuration requested.

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 node table nt. 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 note table nt. 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 table nt, 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 is returned.

The ieee80211_free_allnodes() function will iterate through the node list calling ieee80211_free_node() for all the nodes in table nt.

The ieee80211_iterate_nodes() function will call the user-defined callback function f for all nodes in the table nt. The callback is invoked with the with the user-supplied value arg and a pointer to the current node.

# SEE ALSO

ieee80211(9)

# HISTORY

The ieee80211 series of functions first appeared in NetBSD 1.5, and were later ported to FreeBSD 4.6.

# AUTHORS

This man page was written by Bruce M. Simpson <bms@FreeBSD.org> and Darron Broad <darron@kewl.org>.

September 12, 2006 | NetBSD 7.2