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
202 p2p_remove_client <peer's P2P Device Address|iface=<interface address>>
204 This command can be used to remove the specified client from all groups
205 (operating and persistent) from the local GO. Note that the peer device
206 can rejoin the group if it is in possession of a valid key. See p2p_set
207 per_sta_psk command below for more details on how the peer can be
214 Schedule a P2P service discovery request. The parameters for this
215 command are the device address of the peer device (or 00:00:00:00:00:00
216 for wildcard query that is sent to every discovered P2P peer that
217 supports service discovery) and P2P Service Query TLV(s) as hexdump. For
220 p2p_serv_disc_req 00:00:00:00:00:00 02000001
222 schedules a request for listing all available services of all service
223 discovery protocols and requests this to be sent to all discovered
224 peers (note: this can result in long response frames). The pending
225 requests are sent during device discovery (see p2p_find).
227 Only a single pending wildcard query is supported, but there can be
228 multiple pending peer device specific queries (each will be sent in
229 sequence whenever the peer is found).
231 This command returns an identifier for the pending query (e.g.,
232 "1f77628") that can be used to cancel the request. Directed requests
233 will be automatically removed when the specified peer has replied to
236 Service Query TLV has following format:
237 Length (2 octets, little endian) - length of following data
238 Service Protocol Type (1 octet) - see the table below
239 Service Transaction ID (1 octet) - nonzero identifier for the TLV
240 Query Data (Length - 2 octets of data) - service protocol specific data
242 Service Protocol Types:
243 0 = All service protocols
249 For UPnP, an alternative command format can be used to specify a
250 single query TLV (i.e., a service discovery for a specific UPnP
253 p2p_serv_disc_req 00:00:00:00:00:00 upnp <version hex> <ST: from M-SEARCH>
257 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1
259 Additional examples for queries:
261 # list of all Bonjour services
262 p2p_serv_disc_req 00:00:00:00:00:00 02000101
264 # list of all UPnP services
265 p2p_serv_disc_req 00:00:00:00:00:00 02000201
267 # list of all WS-Discovery services
268 p2p_serv_disc_req 00:00:00:00:00:00 02000301
270 # list of all Bonjour and UPnP services
271 p2p_serv_disc_req 00:00:00:00:00:00 0200010102000202
273 # Apple File Sharing over TCP
274 p2p_serv_disc_req 00:00:00:00:00:00 130001010b5f6166706f766572746370c00c000c01
276 # Bonjour SSTH (supported service type hash)
277 p2p_serv_disc_req 00:00:00:00:00:00 05000101000000
280 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 ssdp:all
281 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 upnp:rootdevice
282 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:service:ContentDirectory:2
283 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 uuid:6859dede-8574-59ab-9332-123456789012
284 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1
286 # Wi-Fi Display examples
287 # format: wifi-display <list of roles> <list of subelements>
288 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source] 2,3,4,5
289 p2p_serv_disc_req 02:01:02:03:04:05 wifi-display [pri-sink] 3
290 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [sec-source] 2
291 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source+sink] 2,3,4,5
292 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source][pri-sink] 2,3,4,5
294 p2p_serv_disc_cancel_req <query identifier>
296 Cancel a pending P2P service discovery request. This command takes a
297 single parameter: identifier for the pending query (the value returned
298 by p2p_serv_disc_req, e.g., "p2p_serv_disc_cancel_req 1f77628".
302 Reply to a service discovery query. This command takes following
303 parameters: frequency in MHz, destination address, dialog token,
304 response TLV(s). The first three parameters are copied from the
305 request event. For example, "p2p_serv_disc_resp 2437 02:40:61:c2:f3:b7
306 1 0300000101". This command is used only if external program is used
307 to process the request (see p2p_serv_disc_external).
311 Indicate that local services have changed. This is used to increment
312 the P2P service indicator value so that peers know when previously
313 cached information may have changed. This is only needed when external
314 service discovery processing is enabled since the commands to
315 pre-configure services for internal processing will increment the
316 indicator automatically.
318 p2p_serv_disc_external <0|1>
320 Configure external processing of P2P service requests: 0 (default) =
321 no external processing of requests (i.e., internal code will process
322 each request based on pre-configured services), 1 = external
323 processing of requests (external program is responsible for replying
324 to service discovery requests with p2p_serv_disc_resp). Please note
325 that there is quite strict limit on how quickly the response needs to
326 be transmitted, so use of the internal processing is strongly
329 p2p_service_add bonjour <query hexdump> <RDATA hexdump>
331 Add a local Bonjour service for internal SD query processing.
336 p2p_service_add bonjour 0b5f6166706f766572746370c00c000c01 074578616d706c65c027
337 # AFP Over TCP (TXT) (RDATA=null)
338 p2p_service_add bonjour 076578616d706c650b5f6166706f766572746370c00c001001 00
340 # IP Printing over TCP (PTR) (RDATA=MyPrinter._ipp._tcp.local.)
341 p2p_service_add bonjour 045f697070c00c000c01 094d795072696e746572c027
342 # IP Printing over TCP (TXT) (RDATA=txtvers=1,pdl=application/postscript)
343 p2p_service_add bonjour 096d797072696e746572045f697070c00c001001 09747874766572733d311a70646c3d6170706c69636174696f6e2f706f7374736372797074
345 # Supported Service Type Hash (SSTH)
346 p2p_service_add bonjour 000000 <32-byte bitfield as hexdump>
347 (note: see P2P spec Annex E.4 for information on how to construct the bitfield)
349 p2p_service_del bonjour <query hexdump>
351 Remove a local Bonjour service from internal SD query processing.
353 p2p_service_add upnp <version hex> <service>
355 Add a local UPnP service for internal SD query processing.
359 p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::upnp:rootdevice
360 p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::upnp:rootdevice
361 p2p_service_add upnp 10 uuid:1122de4e-8574-59ab-9322-333456789044::urn:schemas-upnp-org:service:ContentDirectory:2
362 p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::urn:schemas-upnp-org:service:ContentDirectory:2
363 p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::urn:schemas-upnp-org:device:InternetGatewayDevice:1
365 p2p_service_del upnp <version hex> <service>
367 Remove a local UPnP service from internal SD query processing.
371 Remove all local services from internal SD query processing.
375 p2p_invite [persistent=<network id>|group=<group ifname>] [peer=address]
376 [go_dev_addr=address] [freq=<freq in MHz>] [ht40] [pref=<MHz>]
378 Invite a peer to join a group (e.g., group=wlan1) or to reinvoke a
379 persistent group (e.g., persistent=4). If the peer device is the GO of
380 the persistent group, the peer parameter is not needed. Otherwise it is
381 used to specify which device to invite. go_dev_addr parameter can be
382 used to override the GO device address for Invitation Request should
383 it be not known for some reason (this should not be needed in most
384 cases). When reinvoking a persistent group, the GO device can specify
385 the frequency for the group with the freq parameter. When reinvoking a
386 persistent group, the P2P client device can use freq parameter to force
387 a specific operating channel (or invitation failure if GO rejects that)
388 or pref parameter to request a specific channel (while allowing GO to
389 select to use another channel, if needed).
393 (These are used on the group interface.)
395 wps_pin <any|address> <PIN>
397 Start WPS PIN method. This allows a single WPS Enrollee to connect to
398 the AP/GO. This is used on the GO when a P2P client joins an existing
399 group. The second parameter is the address of the Enrollee or a string
400 "any" to allow any station to use the entered PIN (which will restrict
401 the PIN for one-time-use). PIN is the Enrollee PIN read either from a
402 label or display on the P2P Client/WPS Enrollee.
406 Start WPS PBC method (i.e., push the button). This allows a single WPS
407 Enrollee to connect to the AP/GO. This is used on the GO when a P2P
408 client joins an existing group.
412 Get the passphrase for a group (only available when acting as a GO).
414 p2p_presence_req [<duration> <interval>] [<duration> <interval>]
416 Send a P2P Presence Request to the GO (this is only available when
417 acting as a P2P client). If no duration/interval pairs are given, the
418 request indicates that this client has no special needs for GO
419 presence. the first parameter pair gives the preferred duration and
420 interval values in microseconds. If the second pair is included, that
421 indicates which value would be acceptable.
425 p2p_ext_listen [<period> <interval>]
427 Configure Extended Listen Timing. If the parameters are omitted, this
428 feature is disabled. If the parameters are included, Listen State will
429 be entered every interval msec for at least period msec. Both values
430 have acceptable range of 1-65535 (with interval obviously having to be
431 larger than or equal to duration). If the P2P module is not idle at
432 the time the Extended Listen Timing timeout occurs, the Listen State
433 operation will be skipped.
435 The configured values will also be advertised to other P2P Devices. The
436 received values are available in the p2p_peer command output:
438 ext_listen_period=100 ext_listen_interval=5000
440 p2p_set <field> <value>
442 Change dynamic P2P parameters
444 p2p_set discoverability <0/1>
446 Disable/enable advertisement of client discoverability. This is
447 enabled by default and this parameter is mainly used to allow testing
448 of device discoverability.
450 p2p_set managed <0/1>
452 Disable/enable managed P2P Device operations. This is disabled by
455 p2p_set listen_channel <1/6/11>
457 Set P2P Listen channel. This is mainly meant for testing purposes and
458 changing the Listen channel during normal operations can result in
461 p2p_set ssid_postfix <postfix>
463 Set postfix string to be added to the automatically generated P2P SSID
464 (DIRECT-<two random characters>). For example, postfix of "-testing"
465 could result in the SSID becoming DIRECT-ab-testing.
467 p2p_set per_sta_psk <0/1>
469 Disabled(default)/enables use of per-client PSK in the P2P groups. This
470 can be used to request GO to assign a unique PSK for each client during
471 WPS provisioning. When enabled, this allow clients to be removed from
472 the group securily with p2p_remove_client command since that client's
473 PSK is removed at the same time to prevent it from connecting back using
474 the old PSK. When per-client PSK is not used, the client can still be
475 disconnected, but it will be able to re-join the group since the PSK it
476 learned previously is still valid. It should be noted that the default
477 passphrase on the GO that is normally used to allow legacy stations to
478 connect through manual configuration does not change here, so if that is
479 shared, devices with knowledge of that passphrase can still connect.
483 Set global configuration parameters which may also affect P2P
484 operations. The format on these parameters is same as is used in
485 wpa_supplicant.conf. Only the parameters listen here should be
486 changed. Modifying other parameters may result in incorrect behavior
487 since not all existing users of the parameters are updated.
491 Set WPS UUID (by default, this is generated based on the MAC address).
493 set device_name <device name>
495 Set WPS Device Name (also included in some P2P messages).
497 set manufacturer <manufacturer>
499 Set WPS Manufacturer.
501 set model_name <model name>
505 set model_number <model number>
507 Set WPS Model Number.
509 set serial_number <serial number>
511 Set WPS Serial Number.
513 set device_type <device type>
517 set os_version <OS version>
521 set config_methods <config methods>
523 Set WPS Configuration Methods.
525 set sec_device_type <device type>
527 Add a new Secondary Device Type.
529 set p2p_go_intent <GO intent>
531 Set the default P2P GO Intent. Note: This value can be overridden in
532 p2p_connect command and as such, there should be no need to change the
533 default value here during normal operations.
535 set p2p_ssid_postfix <P2P SSID postfix>
537 Set P2P SSID postfix.
539 set persistent_reconnect <0/1>
541 Disable/enabled persistent reconnect for reinvocation of persistent
542 groups. If enabled, invitations to reinvoke a persistent group will be
543 accepted without separate authorization (e.g., user interaction).
545 set country <two character country code>
547 Set country code (this is included in some P2P messages).
551 p2p_peers [discovered]
553 List P2P Device Addresses of all the P2P peers we know. The optional
554 "discovered" parameter filters out the peers that we have not fully
555 discovered, i.e., which we have only seen in a received Probe Request
558 p2p_peer <P2P Device Address>
560 Fetch information about a known P2P peer.
564 (These are used on the group interface.)
568 Show status information (connection state, role, use encryption
569 parameters, IP address, etc.).
573 Show information about an associated station (when acting in AP/GO role).
577 Lists the currently associated stations.
583 Lists the configured networks, including stored information for
584 persistent groups. The identifier in this list is used with
585 p2p_group_add and p2p_invite to indicate which persistent group is to
588 remove_network <network id>
590 Remove a network entry from configuration.
593 wpa_cli action script
594 ---------------------
596 See examples/p2p-action.sh
598 TODO: describe DHCP/DNS setup
599 TODO: cross-connection