===== P2P howto =====


==== prerequisites ====

In order to test P2P, you need: 
  * a current wireless-testing kernel (or compat-wireless equivalent) or kernel 3.0 later 
  * wpa_supplicant from the [[http://hostap.epitest.fi/gitweb/gitweb.cgi?p=hostap.git;a=summary|hostap]] git tree: 
<code>git clone git://w1.fi/srv/git/hostap.git</code>, or possibly from the hostap-1 stabilisation tree
  * an Atheros ath9k device 
  * OR an ar9170 USB device (with carl9170 driver!) 
  * (OR another device that has a mac80211 driver, but these are known to work, iwlwifi does **not** currently work with any released microcode) 


=== wpa_supplicant ===

Use this config file for compiling: 
<code>CONFIG_DRIVER_NL80211=y
# optional, depending on libnl version you want to use:
# CONFIG_LIBNL20=y

CONFIG_CTRL_IFACE=y
CONFIG_WPS=y
CONFIG_WPS2=y
CONFIG_P2P=y
CONFIG_AP=y

# and maybe DBus</code>

==== running ====

Start wpa_supplicant with this config file: 
<code>ctrl_interface=/var/run/wpa_supplicant
ap_scan=1

device_name=my-device-name
device_type=1-0050F204-1

# If you need to modify the group owner intent, 0-15, the higher
# number indicates preference to become the GO. You can also set
# this on p2p_connect commands.
#p2p_go_intent=15

# optional, can be useful for monitoring, forces
# wpa_supplicant to use only channel 1 rather than
# 1, 6 and 11:
#p2p_listen_reg_class=81
#p2p_listen_channel=1
#p2p_oper_reg_class=81
#p2p_oper_channel=1</code>
like this: 
<code>./wpa_supplicant -Dnl80211 -c /path/to/p2p.conf -i wlan0 -dt</code>
Then start <code>./wpa_cli</code> and use the various <code>p2p_*</code> commands, for example: 
<code>p2p_find
[wait for peer to be found]
p2p_connect <peer-mac-addr> pbc go_intent=<0..15></code>
(or you can use pin of course, go_intent is optional.)


==== using multiple virtual interfaces for concurrent usage ====

If the driver advertises support, wpa_supplicant will automatically create secondary P2P interfaces. To force this without the driver advertising support, you can add the following to the config file: 
<code>driver_param=use_p2p_group_interface=1</code>
When this is added, start the supplicant normally on wlan0 like above. Then, when P2P negotiation finishes, it will create a new interface for the group (called "p2p-wlan0-0") and put it into the appropriate mode (GO or P2P client).