Adding a vendor Information Element to beacon / probe response frames

[Etan Kissling]

Greetings,

I'd like to add a vendor-specific Information Element to the Beacon and Probe Response frames.

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My hostapd.conf looks like this:
=========================================================================
interface=wlan0
# driver=nl80211   # doesn't matter if I choose nl80211 or the default, same behavior
logger_stdout=-1
logger_stdout_level=0
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

ssid=Test
country_code=CH
hw_mode=g
channel=6
vendor_elements=DD<length><oui><subtype><elements>


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Running on Raspberry Pi 3 Model B with the hostapd from apt-get:
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pi at raspberrypi:~ $ hostapd -v
hostapd v2.3
User space daemon for IEEE 802.11 AP management,
IEEE 802.1X/WPA/WPA2/EAP/RADIUS Authenticator
Copyright (c) 2002-2014, Jouni Malinen <j at w1.fi> and contributors


=========================================================================
The AP works fine (I can connect, but don't get an IP because I don't need DHCP -- I just want the vendor element in the beacon for now)
=========================================================================
pi at raspberrypi:~ $ sudo hostapd /etc/hostapd/hostapd.conf
Configuration file: /etc/hostapd/hostapd.conf
Failed to create interface mon.wlan0: -95 (Operation not supported)
wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE
wlan0: Could not connect to kernel driver
Using interface wlan0 with hwaddr yy:yy:yy:yy:yy:yy and ssid "Test"
wlan0: interface state COUNTRY_UPDATE->ENABLED
wlan0: AP-ENABLED 
wlan0: STA xx:xx:xx:xx:xx:xx IEEE 802.11: associated
wlan0: AP-STA-CONNECTED xx:xx:xx:xx:xx:xx
wlan0: STA xx:xx:xx:xx:xx:xx RADIUS: starting accounting session XXXXXXXX-00000000
wlan0: STA xx:xx:xx:xx:xx:xx IEEE 802.11: disassociated
wlan0: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx


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When I check with Wireshark, the vendor element is not included in the beacons, though (OS X with sudo open Wireshark.app, and Monitoring on, while associated with the AP to monitor its channel).
=========================================================================
Frame 610: 206 bytes on wire (1680 bits), 206 bytes captured (1680 bits) on interface 0
Radiotap Header v0, Length 25
802.11 radio information
IEEE 802.11 Beacon frame, Flags: ........C
IEEE 802.11 wireless LAN management frame
    Fixed parameters (12 bytes)
    Tagged parameters (141 bytes)
        Tag: SSID parameter set: Test
        Tag: Supported Rates 1(B), 2(B), 5.5(B), 11(B), 18, 24, 36, 54, [Mbit/sec]
        Tag: DS Parameter set: Current Channel: 6
        Tag: Traffic Indication Map (TIM): DTIM 0 of 0 bitmap
        Tag: Country Information: Country Code CH, Environment Any
        Tag: Power Constraint: 0
        Tag: TPC Report Transmit Power: 17, Link Margin: 0
        Tag: ERP Information
        Tag: Extended Supported Rates 6, 9, 12, 48, [Mbit/sec]
        Tag: HT Capabilities (802.11n D1.10)
        Tag: HT Information (802.11n D1.10)
        Tag: Extended Capabilities (1 octet)
        Tag: Vendor Specific: Broadcom
        Tag: Vendor Specific: Microsof: WMM/WME: Parameter Element



I expect my additional vendor-specific element to be present in this list, but it's not.

How can I expose my vendor-specific Information Element to the Probe response and Beacon frames?


Thanks

Etan