1 wpa_supplicant and Wi-Fi P2P
2 ============================
4 This document describes how the Wi-Fi P2P implementation in
5 wpa_supplicant can be configured and how an external component on the
6 client (e.g., management GUI) is used to enable WPS enrollment and
7 registrar registration.
10 Introduction to Wi-Fi P2P
11 -------------------------
15 More information about Wi-Fi P2P is available from Wi-Fi Alliance:
16 http://www.wi-fi.org/Wi-Fi_Direct.php
19 wpa_supplicant implementation
20 -----------------------------
25 wpa_supplicant configuration
26 ----------------------------
28 Wi-Fi P2P is an optional component that needs to be enabled in the
29 wpa_supplicant build configuration (.config). Here is an example
30 configuration that includes Wi-Fi P2P support and Linux nl80211
31 -based driver interface:
33 CONFIG_DRIVER_NL80211=y
40 In run-time configuration file (wpa_supplicant.conf), some parameters
41 for P2P may be set. In order to make the devices easier to recognize,
42 device_name and device_type should be specified. For example,
43 something like this should be included:
45 ctrl_interface=/var/run/wpa_supplicant
46 device_name=My P2P Device
47 device_type=1-0050F204-1
53 Actual Wi-Fi P2P operations are requested during runtime. These can be
54 done for example using wpa_cli (which is described below) or a GUI
58 wpa_cli starts in interactive mode if no command string is included on
59 the command line. By default, it will select the first network interface
60 that it can find (and that wpa_supplicant controls). If more than one
61 interface is in use, it may be necessary to select one of the explicitly
62 by adding -i argument on the command line (e.g., 'wpa_cli -i wlan1').
64 Most of the P2P operations are done on the main interface (e.g., the
65 interface that is automatically added when the driver is loaded, e.g.,
66 wlan0). When using a separate virtual interface for group operations
67 (e.g., wlan1), the control interface for that group interface may need
68 to be used for some operations (mainly WPS activation in GO). This may
69 change in the future so that all the needed operations could be done
70 over the main control interface.
74 p2p_find [timeout in seconds] [type=<social|progressive>] \
75 [dev_id=<addr>] [delay=<search delay in ms>]
77 The default behavior is to run a single full scan in the beginning and
78 then scan only social channels. type=social will scan only social
79 channels, i.e., it skips the initial full scan. type=progressive is
80 like the default behavior, but it will scan through all the channels
81 progressively one channel at the time in the Search state rounds. This
82 will help in finding new groups or groups missed during the initial
85 The optional dev_id option can be used to specify a single P2P peer to
86 search for. The optional delay parameter can be used to request an extra
87 delay to be used between search iterations (e.g., to free up radio
88 resources for concurrent operations).
90 p2p_listen [timeout in seconds]
92 Start Listen-only state (become discoverable without searching for
93 other devices). Optional parameter can be used to specify the duration
94 for the Listen operation in seconds. This command may not be of that
95 much use during normal operations and is mainly designed for
96 testing. It can also be used to keep the device discoverable without
97 having to maintain a group.
101 Stop ongoing P2P device discovery or other operation (connect, listen
106 Flush P2P peer table and state.
110 p2p_prov_disc <peer device address> <display|keypad|pbc> [join|auto]
112 Send P2P provision discovery request to the specified peer. The
113 parameters for this command are the P2P device address of the peer and
114 the desired configuration method. For example, "p2p_prov_disc
115 02:01:02:03:04:05 display" would request the peer to display a PIN for
116 us and "p2p_prov_disc 02:01:02:03:04:05 keypad" would request the peer
117 to enter a PIN that we display.
119 The optional "join" parameter can be used to indicate that this command
120 is requesting an already running GO to prepare for a new client. This is
121 mainly used with "display" to request it to display a PIN. The "auto"
122 parameter can be used to request wpa_supplicant to automatically figure
123 out whether the peer device is operating as a GO and if so, use
124 join-a-group style PD instead of GO Negotiation style PD.
126 p2p_connect <peer device address> <pbc|pin|PIN#> [display|keypad]
127 [persistent|persistent=<network id>] [join|auth]
128 [go_intent=<0..15>] [freq=<in MHz>] [ht40] [provdisc]
130 Start P2P group formation with a discovered P2P peer. This includes
131 optional group owner negotiation, group interface setup, provisioning,
132 and establishing data connection.
134 The <pbc|pin|PIN#> parameter specifies the WPS provisioning
135 method. "pbc" string starts pushbutton method, "pin" string start PIN
136 method using an automatically generated PIN (which will be returned as
137 the command return code), PIN# means that a pre-selected PIN can be
138 used (e.g., 12345670). [display|keypad] is used with PIN method
139 to specify which PIN is used (display=dynamically generated random PIN
140 from local display, keypad=PIN entered from peer display). "persistent"
141 parameter can be used to request a persistent group to be formed. The
142 "persistent=<network id>" alternative can be used to pre-populate
143 SSID/passphrase configuration based on a previously used persistent
144 group where this device was the GO. The previously used parameters will
145 then be used if the local end becomes the GO in GO Negotiation (which
146 can be forced with go_intent=15).
148 "join" indicates that this is a command to join an existing group as a
149 client. It skips the GO Negotiation part. This will send a Provision
150 Discovery Request message to the target GO before associating for WPS
153 "auth" indicates that the WPS parameters are authorized for the peer
154 device without actually starting GO Negotiation (i.e., the peer is
155 expected to initiate GO Negotiation). This is mainly for testing
158 "go_intent" can be used to override the default GO Intent for this GO
161 "freq" can be used to set a forced operating channel (e.g., freq=2412
162 to select 2.4 GHz channel 1).
164 "provdisc" can be used to request a Provision Discovery exchange to be
165 used prior to starting GO Negotiation as a workaround with some deployed
166 P2P implementations that require this to allow the user to accept the
169 p2p_group_add [persistent|persistent=<network id>] [freq=<freq in MHz>] [ht40]
171 Set up a P2P group owner manually (i.e., without group owner
172 negotiation with a specific peer). This is also known as autonomous
173 GO. Optional persistent=<network id> can be used to specify restart of
174 a persistent group. Optional freq=<freq in MHz> can be used to force
175 the GO to be started on a specific frequency. Special freq=2 or freq=5
176 options can be used to request the best 2.4 GHz or 5 GHz band channel
177 to be selected automatically.
179 p2p_reject <peer device address>
181 Reject connection attempt from a peer (specified with a device
182 address). This is a mechanism to reject a pending GO Negotiation with
183 a peer and request to automatically block any further connection or
184 discovery of the peer.
186 p2p_group_remove <group interface>
188 Terminate a P2P group. If a new virtual network interface was used for
189 the group, it will also be removed. The network interface name of the
190 group interface is used as a parameter for this command.
194 Cancel an ongoing P2P group formation and joining-a-group related
195 operation. This operations unauthorizes the specific peer device (if any
196 had been authorized to start group formation), stops P2P find (if in
197 progress), stops pending operations for join-a-group, and removes the
198 P2P group interface (if one was used) that is in the WPS provisioning
199 step. If the WPS provisioning step has been completed, the group is not
206 Schedule a P2P service discovery request. The parameters for this
207 command are the device address of the peer device (or 00:00:00:00:00:00
208 for wildcard query that is sent to every discovered P2P peer that
209 supports service discovery) and P2P Service Query TLV(s) as hexdump. For
212 p2p_serv_disc_req 00:00:00:00:00:00 02000001
214 schedules a request for listing all available services of all service
215 discovery protocols and requests this to be sent to all discovered
216 peers (note: this can result in long response frames). The pending
217 requests are sent during device discovery (see p2p_find).
219 Only a single pending wildcard query is supported, but there can be
220 multiple pending peer device specific queries (each will be sent in
221 sequence whenever the peer is found).
223 This command returns an identifier for the pending query (e.g.,
224 "1f77628") that can be used to cancel the request. Directed requests
225 will be automatically removed when the specified peer has replied to
228 Service Query TLV has following format:
229 Length (2 octets, little endian) - length of following data
230 Service Protocol Type (1 octet) - see the table below
231 Service Transaction ID (1 octet) - nonzero identifier for the TLV
232 Query Data (Length - 2 octets of data) - service protocol specific data
234 Service Protocol Types:
235 0 = All service protocols
241 For UPnP, an alternative command format can be used to specify a
242 single query TLV (i.e., a service discovery for a specific UPnP
245 p2p_serv_disc_req 00:00:00:00:00:00 upnp <version hex> <ST: from M-SEARCH>
249 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1
251 Additional examples for queries:
253 # list of all Bonjour services
254 p2p_serv_disc_req 00:00:00:00:00:00 02000101
256 # list of all UPnP services
257 p2p_serv_disc_req 00:00:00:00:00:00 02000201
259 # list of all WS-Discovery services
260 p2p_serv_disc_req 00:00:00:00:00:00 02000301
262 # list of all Bonjour and UPnP services
263 p2p_serv_disc_req 00:00:00:00:00:00 0200010102000202
265 # Apple File Sharing over TCP
266 p2p_serv_disc_req 00:00:00:00:00:00 130001010b5f6166706f766572746370c00c000c01
268 # Bonjour SSTH (supported service type hash)
269 p2p_serv_disc_req 00:00:00:00:00:00 05000101000000
272 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 ssdp:all
273 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 upnp:rootdevice
274 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:service:ContentDirectory:2
275 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 uuid:6859dede-8574-59ab-9332-123456789012
276 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1
278 # Wi-Fi Display examples
279 # format: wifi-display <list of roles> <list of subelements>
280 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source] 2,3,4,5
281 p2p_serv_disc_req 02:01:02:03:04:05 wifi-display [pri-sink] 3
282 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [sec-source] 2
283 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source+sink] 2,3,4,5
284 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source][pri-sink] 2,3,4,5
286 p2p_serv_disc_cancel_req <query identifier>
288 Cancel a pending P2P service discovery request. This command takes a
289 single parameter: identifier for the pending query (the value returned
290 by p2p_serv_disc_req, e.g., "p2p_serv_disc_cancel_req 1f77628".
294 Reply to a service discovery query. This command takes following
295 parameters: frequency in MHz, destination address, dialog token,
296 response TLV(s). The first three parameters are copied from the
297 request event. For example, "p2p_serv_disc_resp 2437 02:40:61:c2:f3:b7
298 1 0300000101". This command is used only if external program is used
299 to process the request (see p2p_serv_disc_external).
303 Indicate that local services have changed. This is used to increment
304 the P2P service indicator value so that peers know when previously
305 cached information may have changed. This is only needed when external
306 service discovery processing is enabled since the commands to
307 pre-configure services for internal processing will increment the
308 indicator automatically.
310 p2p_serv_disc_external <0|1>
312 Configure external processing of P2P service requests: 0 (default) =
313 no external processing of requests (i.e., internal code will process
314 each request based on pre-configured services), 1 = external
315 processing of requests (external program is responsible for replying
316 to service discovery requests with p2p_serv_disc_resp). Please note
317 that there is quite strict limit on how quickly the response needs to
318 be transmitted, so use of the internal processing is strongly
321 p2p_service_add bonjour <query hexdump> <RDATA hexdump>
323 Add a local Bonjour service for internal SD query processing.
328 p2p_service_add bonjour 0b5f6166706f766572746370c00c000c01 074578616d706c65c027
329 # AFP Over TCP (TXT) (RDATA=null)
330 p2p_service_add bonjour 076578616d706c650b5f6166706f766572746370c00c001001 00
332 # IP Printing over TCP (PTR) (RDATA=MyPrinter._ipp._tcp.local.)
333 p2p_service_add bonjour 045f697070c00c000c01 094d795072696e746572c027
334 # IP Printing over TCP (TXT) (RDATA=txtvers=1,pdl=application/postscript)
335 p2p_service_add bonjour 096d797072696e746572045f697070c00c001001 09747874766572733d311a70646c3d6170706c69636174696f6e2f706f7374736372797074
337 # Supported Service Type Hash (SSTH)
338 p2p_service_add bonjour 000000 <32-byte bitfield as hexdump>
339 (note: see P2P spec Annex E.4 for information on how to construct the bitfield)
341 p2p_service_del bonjour <query hexdump>
343 Remove a local Bonjour service from internal SD query processing.
345 p2p_service_add upnp <version hex> <service>
347 Add a local UPnP service for internal SD query processing.
351 p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::upnp:rootdevice
352 p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::upnp:rootdevice
353 p2p_service_add upnp 10 uuid:1122de4e-8574-59ab-9322-333456789044::urn:schemas-upnp-org:service:ContentDirectory:2
354 p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::urn:schemas-upnp-org:service:ContentDirectory:2
355 p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::urn:schemas-upnp-org:device:InternetGatewayDevice:1
357 p2p_service_del upnp <version hex> <service>
359 Remove a local UPnP service from internal SD query processing.
363 Remove all local services from internal SD query processing.
367 p2p_invite [persistent=<network id>|group=<group ifname>] [peer=address]
368 [go_dev_addr=address] [freq=<freq in MHz>] [ht40] [pref=<MHz>]
370 Invite a peer to join a group (e.g., group=wlan1) or to reinvoke a
371 persistent group (e.g., persistent=4). If the peer device is the GO of
372 the persistent group, the peer parameter is not needed. Otherwise it is
373 used to specify which device to invite. go_dev_addr parameter can be
374 used to override the GO device address for Invitation Request should
375 it be not known for some reason (this should not be needed in most
376 cases). When reinvoking a persistent group, the GO device can specify
377 the frequency for the group with the freq parameter. When reinvoking a
378 persistent group, the P2P client device can use freq parameter to force
379 a specific operating channel (or invitation failure if GO rejects that)
380 or pref parameter to request a specific channel (while allowing GO to
381 select to use another channel, if needed).
385 (These are used on the group interface.)
387 wps_pin <any|address> <PIN>
389 Start WPS PIN method. This allows a single WPS Enrollee to connect to
390 the AP/GO. This is used on the GO when a P2P client joins an existing
391 group. The second parameter is the address of the Enrollee or a string
392 "any" to allow any station to use the entered PIN (which will restrict
393 the PIN for one-time-use). PIN is the Enrollee PIN read either from a
394 label or display on the P2P Client/WPS Enrollee.
398 Start WPS PBC method (i.e., push the button). This allows a single WPS
399 Enrollee to connect to the AP/GO. This is used on the GO when a P2P
400 client joins an existing group.
404 Get the passphrase for a group (only available when acting as a GO).
406 p2p_presence_req [<duration> <interval>] [<duration> <interval>]
408 Send a P2P Presence Request to the GO (this is only available when
409 acting as a P2P client). If no duration/interval pairs are given, the
410 request indicates that this client has no special needs for GO
411 presence. the first parameter pair gives the preferred duration and
412 interval values in microseconds. If the second pair is included, that
413 indicates which value would be acceptable.
417 p2p_ext_listen [<period> <interval>]
419 Configure Extended Listen Timing. If the parameters are omitted, this
420 feature is disabled. If the parameters are included, Listen State will
421 be entered every interval msec for at least period msec. Both values
422 have acceptable range of 1-65535 (with interval obviously having to be
423 larger than or equal to duration). If the P2P module is not idle at
424 the time the Extended Listen Timing timeout occurs, the Listen State
425 operation will be skipped.
427 The configured values will also be advertised to other P2P Devices. The
428 received values are available in the p2p_peer command output:
430 ext_listen_period=100 ext_listen_interval=5000
432 p2p_set <field> <value>
434 Change dynamic P2P parameters
436 p2p_set discoverability <0/1>
438 Disable/enable advertisement of client discoverability. This is
439 enabled by default and this parameter is mainly used to allow testing
440 of device discoverability.
442 p2p_set managed <0/1>
444 Disable/enable managed P2P Device operations. This is disabled by
447 p2p_set listen_channel <1/6/11>
449 Set P2P Listen channel. This is mainly meant for testing purposes and
450 changing the Listen channel during normal operations can result in
453 p2p_set ssid_postfix <postfix>
455 Set postfix string to be added to the automatically generated P2P SSID
456 (DIRECT-<two random characters>). For example, postfix of "-testing"
457 could result in the SSID becoming DIRECT-ab-testing.
461 Set global configuration parameters which may also affect P2P
462 operations. The format on these parameters is same as is used in
463 wpa_supplicant.conf. Only the parameters listen here should be
464 changed. Modifying other parameters may result in incorrect behavior
465 since not all existing users of the parameters are updated.
469 Set WPS UUID (by default, this is generated based on the MAC address).
471 set device_name <device name>
473 Set WPS Device Name (also included in some P2P messages).
475 set manufacturer <manufacturer>
477 Set WPS Manufacturer.
479 set model_name <model name>
483 set model_number <model number>
485 Set WPS Model Number.
487 set serial_number <serial number>
489 Set WPS Serial Number.
491 set device_type <device type>
495 set os_version <OS version>
499 set config_methods <config methods>
501 Set WPS Configuration Methods.
503 set sec_device_type <device type>
505 Add a new Secondary Device Type.
507 set p2p_go_intent <GO intent>
509 Set the default P2P GO Intent. Note: This value can be overridden in
510 p2p_connect command and as such, there should be no need to change the
511 default value here during normal operations.
513 set p2p_ssid_postfix <P2P SSID postfix>
515 Set P2P SSID postfix.
517 set persistent_reconnect <0/1>
519 Disable/enabled persistent reconnect for reinvocation of persistent
520 groups. If enabled, invitations to reinvoke a persistent group will be
521 accepted without separate authorization (e.g., user interaction).
523 set country <two character country code>
525 Set country code (this is included in some P2P messages).
529 p2p_peers [discovered]
531 List P2P Device Addresses of all the P2P peers we know. The optional
532 "discovered" parameter filters out the peers that we have not fully
533 discovered, i.e., which we have only seen in a received Probe Request
536 p2p_peer <P2P Device Address>
538 Fetch information about a known P2P peer.
542 (These are used on the group interface.)
546 Show status information (connection state, role, use encryption
547 parameters, IP address, etc.).
551 Show information about an associated station (when acting in AP/GO role).
555 Lists the currently associated stations.
561 Lists the configured networks, including stored information for
562 persistent groups. The identifier in this list is used with
563 p2p_group_add and p2p_invite to indicate which persistent group is to
566 remove_network <network id>
568 Remove a network entry from configuration.
571 wpa_cli action script
572 ---------------------
574 See examples/p2p-action.sh
576 TODO: describe DHCP/DNS setup
577 TODO: cross-connection