IEEE80211(4)

NAME
ieee80211 - standard interface to IEEE 802.11 devices

SYNOPSIS
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/ethernet.h>
#include <net/if_ieee80211.h>

DESCRIPTION
This section describes the standard interface to configuration and status information on IEEE 802.11 devices. Most devices support options not configurable by this interface. They must be set by their respective, specific control program. The interface is via one of the following ioctl(2) calls on a socket:

SIOCG80211
    Get configuration or status information.

SIOCS80211
    Set configuration information.

These requests are made via a modified ifreq structure. This structure is defined as follows:

    struct ieee80211req {
    	char		i_name[IFNAMSIZ];	/* if_name, e.g. "wi0" */
    	uint16_t	i_type;			/* req type */
    	int16_t		i_val;			/* Index or simple value */
    	int16_t		i_len;			/* Index or simple value */
    	void		*i_data;		/* Extra data */
    };

For SIOCG80211 the following values of i_type are valid:

IEEE80211_IOC_SSID
    Returns the requested SSID by copying it into the buffer pointed to by i_data and setting i_len to the length. If i_val is >= 0 then the request refers to the configured value for that slot. Generally, 0 is the only valid value, but some interfaces support more SSIDs. If i_val is -1 then the request refers to the currently active value.

IEEE80211_IOC_NUMSSIDS
    Returns the number of SSIDs this card supports. In most cases, this is 1, but some devices such as an(4) support more.

IEEE80211_IOC_WEP
    Returns the current WEP status in i_val. Valid values are IEEE80211_WEP_NOSUP, IEEE80211_WEP_ON, IEEE80211_WEP_OFF, and IEEE80211_WEP_MIXED. Respectively, these values mean unsupported, mandatory for all devices, off, and on, but not required for all devices.

IEEE80211_IOC_WEPKEY
    Returns the requested WEP key via i_data and its length via i_len. If the device does not support returning the WEP key or the user is not root then the key may be returned as all zeros. Technically this is a valid key, but it is the kind of key an idiot would put on his luggage so we use it as a special value. Generally, only four WEP keys are allowed, but some devices support more. If so, the first four (0-3) are the standard keys stored in volatile storage and the others are device specific.

IEEE80211_IOC_NUMWEPKEYS
    Returns the number of WEP keys supported by this device, generally 4. A device that does not support WEP may either report 0 or simply return EINVAL.

IEEE80211_IOC_WEPTXKEY
    Returns the WEP key used for transmission.

IEEE80211_IOC_AUTHMODE
    Returns the current authentication mode in i_val. Valid values are IEEE80211_AUTH_NONE, IEEE80211_AUTH_OPEN, and IEEE80211_AUTH_SHARED.

IEEE80211_IOC_STATIONNAME
    Returns the station name via i_data and its length via i_len. While all known devices seem to support this in some way or another, they all do it differently and it appears to not have anything to do with the actual IEEE 802.11 standard so making up an answer may be necessary for future devices.

IEEE80211_IOC_CHANNEL
    Returns the current direct sequence spread spectrum channel in use.

IEEE80211_IOC_POWERSAVE
    Returns the current powersaving mode. Valid values are IEEE80211_POWERSAVE_NOSUP, IEEE80211_POWERSAVE_OFF, IEEE80211_POWERSAVE_ON, IEEE80211_POWERSAVE_CAM, IEEE80211_POWERSAVE_PSP, and IEEE80211_POWERSAVE_PSP_CAM. Currently, IEEE80211_POWERSAVE_ON is defined to be equal to IEEE80211_POWERSAVE_CAM, but this may be incorrect.

IEEE80211_IOC_POWERSAVESLEEP
    Returns the powersave sleep time in msec in i_val.

For SIOCS80211 the following values of i_type are valid:

IEEE80211_IOC_SSID
    Set the desired SSID for infrastructure and ad-hoc modes to value given by i_data and i_len. The length should be no longer than 32 characters.

IEEE80211_IOC_WEP
    Set the current WEP mode to the value given in i_val. Valid values are the same as those for this value above. Devices which do not support all modes may choose to either return EINVAL or choose a reasonable alternate (supported) setting.

IEEE80211_IOC_WEPKEY
    Set the WEP key indicated by i_val to the value given by i_data and i_len. Generally, valid values of i_len are 0, 5, and 13 though not all devices with WEP support have support for 13-byte keys.

IEEE80211_IOC_WEPTXKEY
    Set the WEP key used for transmission to the value in i_val. Not all values which are valid for setting keys may be valid for setting transmit keys due to strange device interfaces.

IEEE80211_IOC_AUTHMODE
    Set the current authorization mode to the value given in i_val. Valid values are given above. Not all devices support this.

IEEE80211_IOC_STATIONNAME
    Set the station name to the value given by i_data and i_len. The standard does not appear to deal with this feature so the range of valid values may vary from device to device.

IEEE80211_IOC_CHANNEL
    Set the desired ad-hoc channel to the value given by i_val. On some devices this has an impact on infrastructure mode as well. Valid values are 1-14, but 0 should be allowed and should return the device to the default value. Many devices support this directly by converting any invalid value to the default value.

IEEE80211_IOC_POWERSAVE
    Set the current powersaving mode to the value given in i_val. Valid values are the same as those for this value above. Devices which do not support all modes may choose to either return EINVAL or choose a reasonable alternate (supported) setting. Most devices only support CAM mode.

IEEE80211_IOC_POWERSAVESLEEP
    Set the powersave sleep time in msec to the value in i_val.

SEE ALSO
ioctl(2), an(4), ray(4), wi(4), ifconfig(8)

HISTORY
The ieee80211 manual appeared in FreeBSD 4.3.