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>] [dev_type=<device type>] \
76 [delay=<search delay in ms>]
78 The default behavior is to run a single full scan in the beginning and
79 then scan only social channels. type=social will scan only social
80 channels, i.e., it skips the initial full scan. type=progressive is
81 like the default behavior, but it will scan through all the channels
82 progressively one channel at the time in the Search state rounds. This
83 will help in finding new groups or groups missed during the initial
86 The optional dev_id option can be used to specify a single P2P peer to
87 search for. The optional delay parameter can be used to request an extra
88 delay to be used between search iterations (e.g., to free up radio
89 resources for concurrent operations).
91 The optional dev_type option can be used to specify a single device type
92 (primary or secondary) to search for, e.g.,
93 "p2p_find dev_type=1-0050F204-1".
95 p2p_listen [timeout in seconds]
97 Start Listen-only state (become discoverable without searching for
98 other devices). Optional parameter can be used to specify the duration
99 for the Listen operation in seconds. This command may not be of that
100 much use during normal operations and is mainly designed for
101 testing. It can also be used to keep the device discoverable without
102 having to maintain a group.
106 Stop ongoing P2P device discovery or other operation (connect, listen
111 Flush P2P peer table and state.
115 p2p_prov_disc <peer device address> <display|keypad|pbc> [join|auto]
117 Send P2P provision discovery request to the specified peer. The
118 parameters for this command are the P2P device address of the peer and
119 the desired configuration method. For example, "p2p_prov_disc
120 02:01:02:03:04:05 display" would request the peer to display a PIN for
121 us and "p2p_prov_disc 02:01:02:03:04:05 keypad" would request the peer
122 to enter a PIN that we display.
124 The optional "join" parameter can be used to indicate that this command
125 is requesting an already running GO to prepare for a new client. This is
126 mainly used with "display" to request it to display a PIN. The "auto"
127 parameter can be used to request wpa_supplicant to automatically figure
128 out whether the peer device is operating as a GO and if so, use
129 join-a-group style PD instead of GO Negotiation style PD.
131 p2p_connect <peer device address> <pbc|pin|PIN#> [display|keypad]
132 [persistent|persistent=<network id>] [join|auth]
133 [go_intent=<0..15>] [freq=<in MHz>] [ht40] [vht] [provdisc]
135 Start P2P group formation with a discovered P2P peer. This includes
136 optional group owner negotiation, group interface setup, provisioning,
137 and establishing data connection.
139 The <pbc|pin|PIN#> parameter specifies the WPS provisioning
140 method. "pbc" string starts pushbutton method, "pin" string start PIN
141 method using an automatically generated PIN (which will be returned as
142 the command return code), PIN# means that a pre-selected PIN can be
143 used (e.g., 12345670). [display|keypad] is used with PIN method
144 to specify which PIN is used (display=dynamically generated random PIN
145 from local display, keypad=PIN entered from peer display). "persistent"
146 parameter can be used to request a persistent group to be formed. The
147 "persistent=<network id>" alternative can be used to pre-populate
148 SSID/passphrase configuration based on a previously used persistent
149 group where this device was the GO. The previously used parameters will
150 then be used if the local end becomes the GO in GO Negotiation (which
151 can be forced with go_intent=15).
153 "join" indicates that this is a command to join an existing group as a
154 client. It skips the GO Negotiation part. This will send a Provision
155 Discovery Request message to the target GO before associating for WPS
158 "auth" indicates that the WPS parameters are authorized for the peer
159 device without actually starting GO Negotiation (i.e., the peer is
160 expected to initiate GO Negotiation). This is mainly for testing
163 "go_intent" can be used to override the default GO Intent for this GO
166 "freq" can be used to set a forced operating channel (e.g., freq=2412
167 to select 2.4 GHz channel 1).
169 "provdisc" can be used to request a Provision Discovery exchange to be
170 used prior to starting GO Negotiation as a workaround with some deployed
171 P2P implementations that require this to allow the user to accept the
174 p2p_group_add [persistent|persistent=<network id>] [freq=<freq in MHz>]
177 Set up a P2P group owner manually (i.e., without group owner
178 negotiation with a specific peer). This is also known as autonomous
179 GO. Optional persistent=<network id> can be used to specify restart of
180 a persistent group. Optional freq=<freq in MHz> can be used to force
181 the GO to be started on a specific frequency. Special freq=2 or freq=5
182 options can be used to request the best 2.4 GHz or 5 GHz band channel
183 to be selected automatically.
185 p2p_reject <peer device address>
187 Reject connection attempt from a peer (specified with a device
188 address). This is a mechanism to reject a pending GO Negotiation with
189 a peer and request to automatically block any further connection or
190 discovery of the peer.
192 p2p_group_remove <group interface>
194 Terminate a P2P group. If a new virtual network interface was used for
195 the group, it will also be removed. The network interface name of the
196 group interface is used as a parameter for this command.
200 Cancel an ongoing P2P group formation and joining-a-group related
201 operation. This operations unauthorizes the specific peer device (if any
202 had been authorized to start group formation), stops P2P find (if in
203 progress), stops pending operations for join-a-group, and removes the
204 P2P group interface (if one was used) that is in the WPS provisioning
205 step. If the WPS provisioning step has been completed, the group is not
208 p2p_remove_client <peer's P2P Device Address|iface=<interface address>>
210 This command can be used to remove the specified client from all groups
211 (operating and persistent) from the local GO. Note that the peer device
212 can rejoin the group if it is in possession of a valid key. See p2p_set
213 per_sta_psk command below for more details on how the peer can be
220 Schedule a P2P service discovery request. The parameters for this
221 command are the device address of the peer device (or 00:00:00:00:00:00
222 for wildcard query that is sent to every discovered P2P peer that
223 supports service discovery) and P2P Service Query TLV(s) as hexdump. For
226 p2p_serv_disc_req 00:00:00:00:00:00 02000001
228 schedules a request for listing all available services of all service
229 discovery protocols and requests this to be sent to all discovered
230 peers (note: this can result in long response frames). The pending
231 requests are sent during device discovery (see p2p_find).
233 There can be multiple pending peer device specific queries (each will be
234 sent in sequence whenever the peer is found).
236 This command returns an identifier for the pending query (e.g.,
237 "1f77628") that can be used to cancel the request. Directed requests
238 will be automatically removed when the specified peer has replied to
241 Service Query TLV has following format:
242 Length (2 octets, little endian) - length of following data
243 Service Protocol Type (1 octet) - see the table below
244 Service Transaction ID (1 octet) - nonzero identifier for the TLV
245 Query Data (Length - 2 octets of data) - service protocol specific data
247 Service Protocol Types:
248 0 = All service protocols
254 For UPnP, an alternative command format can be used to specify a
255 single query TLV (i.e., a service discovery for a specific UPnP
258 p2p_serv_disc_req 00:00:00:00:00:00 upnp <version hex> <ST: from M-SEARCH>
262 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1
264 Additional examples for queries:
266 # list of all Bonjour services
267 p2p_serv_disc_req 00:00:00:00:00:00 02000101
269 # list of all UPnP services
270 p2p_serv_disc_req 00:00:00:00:00:00 02000201
272 # list of all WS-Discovery services
273 p2p_serv_disc_req 00:00:00:00:00:00 02000301
275 # list of all Bonjour and UPnP services
276 p2p_serv_disc_req 00:00:00:00:00:00 0200010102000202
278 # Apple File Sharing over TCP
279 p2p_serv_disc_req 00:00:00:00:00:00 130001010b5f6166706f766572746370c00c000c01
281 # Bonjour SSTH (supported service type hash)
282 p2p_serv_disc_req 00:00:00:00:00:00 05000101000000
285 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 ssdp:all
286 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 upnp:rootdevice
287 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:service:ContentDirectory:2
288 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 uuid:6859dede-8574-59ab-9332-123456789012
289 p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1
291 # Wi-Fi Display examples
292 # format: wifi-display <list of roles> <list of subelements>
293 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source] 2,3,4,5
294 p2p_serv_disc_req 02:01:02:03:04:05 wifi-display [pri-sink] 3
295 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [sec-source] 2
296 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source+sink] 2,3,4,5
297 p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source][pri-sink] 2,3,4,5
299 p2p_serv_disc_cancel_req <query identifier>
301 Cancel a pending P2P service discovery request. This command takes a
302 single parameter: identifier for the pending query (the value returned
303 by p2p_serv_disc_req, e.g., "p2p_serv_disc_cancel_req 1f77628".
307 Reply to a service discovery query. This command takes following
308 parameters: frequency in MHz, destination address, dialog token,
309 response TLV(s). The first three parameters are copied from the
310 request event. For example, "p2p_serv_disc_resp 2437 02:40:61:c2:f3:b7
311 1 0300000101". This command is used only if external program is used
312 to process the request (see p2p_serv_disc_external).
316 Indicate that local services have changed. This is used to increment
317 the P2P service indicator value so that peers know when previously
318 cached information may have changed. This is only needed when external
319 service discovery processing is enabled since the commands to
320 pre-configure services for internal processing will increment the
321 indicator automatically.
323 p2p_serv_disc_external <0|1>
325 Configure external processing of P2P service requests: 0 (default) =
326 no external processing of requests (i.e., internal code will process
327 each request based on pre-configured services), 1 = external
328 processing of requests (external program is responsible for replying
329 to service discovery requests with p2p_serv_disc_resp). Please note
330 that there is quite strict limit on how quickly the response needs to
331 be transmitted, so use of the internal processing is strongly
334 p2p_service_add bonjour <query hexdump> <RDATA hexdump>
336 Add a local Bonjour service for internal SD query processing.
341 p2p_service_add bonjour 0b5f6166706f766572746370c00c000c01 074578616d706c65c027
342 # AFP Over TCP (TXT) (RDATA=null)
343 p2p_service_add bonjour 076578616d706c650b5f6166706f766572746370c00c001001 00
345 # IP Printing over TCP (PTR) (RDATA=MyPrinter._ipp._tcp.local.)
346 p2p_service_add bonjour 045f697070c00c000c01 094d795072696e746572c027
347 # IP Printing over TCP (TXT) (RDATA=txtvers=1,pdl=application/postscript)
348 p2p_service_add bonjour 096d797072696e746572045f697070c00c001001 09747874766572733d311a70646c3d6170706c69636174696f6e2f706f7374736372797074
350 # Supported Service Type Hash (SSTH)
351 p2p_service_add bonjour 000000 <32-byte bitfield as hexdump>
352 (note: see P2P spec Annex E.4 for information on how to construct the bitfield)
354 p2p_service_del bonjour <query hexdump>
356 Remove a local Bonjour service from internal SD query processing.
358 p2p_service_add upnp <version hex> <service>
360 Add a local UPnP service for internal SD query processing.
364 p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::upnp:rootdevice
365 p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::upnp:rootdevice
366 p2p_service_add upnp 10 uuid:1122de4e-8574-59ab-9322-333456789044::urn:schemas-upnp-org:service:ContentDirectory:2
367 p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::urn:schemas-upnp-org:service:ContentDirectory:2
368 p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::urn:schemas-upnp-org:device:InternetGatewayDevice:1
370 p2p_service_del upnp <version hex> <service>
372 Remove a local UPnP service from internal SD query processing.
376 Remove all local services from internal SD query processing.
380 p2p_invite [persistent=<network id>|group=<group ifname>] [peer=address]
381 [go_dev_addr=address] [freq=<freq in MHz>] [ht40] [vht]
384 Invite a peer to join a group (e.g., group=wlan1) or to reinvoke a
385 persistent group (e.g., persistent=4). If the peer device is the GO of
386 the persistent group, the peer parameter is not needed. Otherwise it is
387 used to specify which device to invite. go_dev_addr parameter can be
388 used to override the GO device address for Invitation Request should
389 it be not known for some reason (this should not be needed in most
390 cases). When reinvoking a persistent group, the GO device can specify
391 the frequency for the group with the freq parameter. When reinvoking a
392 persistent group, the P2P client device can use freq parameter to force
393 a specific operating channel (or invitation failure if GO rejects that)
394 or pref parameter to request a specific channel (while allowing GO to
395 select to use another channel, if needed).
399 (These are used on the group interface.)
401 wps_pin <any|address> <PIN>
403 Start WPS PIN method. This allows a single WPS Enrollee to connect to
404 the AP/GO. This is used on the GO when a P2P client joins an existing
405 group. The second parameter is the address of the Enrollee or a string
406 "any" to allow any station to use the entered PIN (which will restrict
407 the PIN for one-time-use). PIN is the Enrollee PIN read either from a
408 label or display on the P2P Client/WPS Enrollee.
412 Start WPS PBC method (i.e., push the button). This allows a single WPS
413 Enrollee to connect to the AP/GO. This is used on the GO when a P2P
414 client joins an existing group.
418 Get the passphrase for a group (only available when acting as a GO).
420 p2p_presence_req [<duration> <interval>] [<duration> <interval>]
422 Send a P2P Presence Request to the GO (this is only available when
423 acting as a P2P client). If no duration/interval pairs are given, the
424 request indicates that this client has no special needs for GO
425 presence. The first parameter pair gives the preferred duration and
426 interval values in microseconds. If the second pair is included, that
427 indicates which value would be acceptable. This command returns OK
428 immediately and the response from the GO is indicated in a
429 P2P-PRESENCE-RESPONSE event message.
433 p2p_ext_listen [<period> <interval>]
435 Configure Extended Listen Timing. If the parameters are omitted, this
436 feature is disabled. If the parameters are included, Listen State will
437 be entered every interval msec for at least period msec. Both values
438 have acceptable range of 1-65535 (with interval obviously having to be
439 larger than or equal to duration). If the P2P module is not idle at
440 the time the Extended Listen Timing timeout occurs, the Listen State
441 operation will be skipped.
443 The configured values will also be advertised to other P2P Devices. The
444 received values are available in the p2p_peer command output:
446 ext_listen_period=100 ext_listen_interval=5000
448 p2p_set <field> <value>
450 Change dynamic P2P parameters
452 p2p_set discoverability <0/1>
454 Disable/enable advertisement of client discoverability. This is
455 enabled by default and this parameter is mainly used to allow testing
456 of device discoverability.
458 p2p_set managed <0/1>
460 Disable/enable managed P2P Device operations. This is disabled by
463 p2p_set listen_channel <1/6/11>
465 Set P2P Listen channel. This is mainly meant for testing purposes and
466 changing the Listen channel during normal operations can result in
469 p2p_set ssid_postfix <postfix>
471 Set postfix string to be added to the automatically generated P2P SSID
472 (DIRECT-<two random characters>). For example, postfix of "-testing"
473 could result in the SSID becoming DIRECT-ab-testing.
475 p2p_set per_sta_psk <0/1>
477 Disabled(default)/enables use of per-client PSK in the P2P groups. This
478 can be used to request GO to assign a unique PSK for each client during
479 WPS provisioning. When enabled, this allow clients to be removed from
480 the group securily with p2p_remove_client command since that client's
481 PSK is removed at the same time to prevent it from connecting back using
482 the old PSK. When per-client PSK is not used, the client can still be
483 disconnected, but it will be able to re-join the group since the PSK it
484 learned previously is still valid. It should be noted that the default
485 passphrase on the GO that is normally used to allow legacy stations to
486 connect through manual configuration does not change here, so if that is
487 shared, devices with knowledge of that passphrase can still connect.
491 Set global configuration parameters which may also affect P2P
492 operations. The format on these parameters is same as is used in
493 wpa_supplicant.conf. Only the parameters listen here should be
494 changed. Modifying other parameters may result in incorrect behavior
495 since not all existing users of the parameters are updated.
499 Set WPS UUID (by default, this is generated based on the MAC address).
501 set device_name <device name>
503 Set WPS Device Name (also included in some P2P messages).
505 set manufacturer <manufacturer>
507 Set WPS Manufacturer.
509 set model_name <model name>
513 set model_number <model number>
515 Set WPS Model Number.
517 set serial_number <serial number>
519 Set WPS Serial Number.
521 set device_type <device type>
525 set os_version <OS version>
529 set config_methods <config methods>
531 Set WPS Configuration Methods.
533 set sec_device_type <device type>
535 Add a new Secondary Device Type.
537 set p2p_go_intent <GO intent>
539 Set the default P2P GO Intent. Note: This value can be overridden in
540 p2p_connect command and as such, there should be no need to change the
541 default value here during normal operations.
543 set p2p_ssid_postfix <P2P SSID postfix>
545 Set P2P SSID postfix.
547 set persistent_reconnect <0/1>
549 Disable/enabled persistent reconnect for reinvocation of persistent
550 groups. If enabled, invitations to reinvoke a persistent group will be
551 accepted without separate authorization (e.g., user interaction).
553 set country <two character country code>
555 Set country code (this is included in some P2P messages).
557 set p2p_search_delay <delay>
559 Set p2p_search_delay which adds extra delay in milliseconds between
560 concurrent search iterations to make p2p_find friendlier to concurrent
561 operations by avoiding it from taking 100% of radio resources. The
562 default value is 500 ms.
566 p2p_peers [discovered]
568 List P2P Device Addresses of all the P2P peers we know. The optional
569 "discovered" parameter filters out the peers that we have not fully
570 discovered, i.e., which we have only seen in a received Probe Request
573 p2p_peer <P2P Device Address>
575 Fetch information about a known P2P peer.
579 (These are used on the group interface.)
583 Show status information (connection state, role, use encryption
584 parameters, IP address, etc.).
588 Show information about an associated station (when acting in AP/GO role).
592 Lists the currently associated stations.
598 Lists the configured networks, including stored information for
599 persistent groups. The identifier in this list is used with
600 p2p_group_add and p2p_invite to indicate which persistent group is to
603 remove_network <network id>
605 Remove a network entry from configuration.
608 wpa_cli action script
609 ---------------------
611 See examples/p2p-action.sh
613 TODO: describe DHCP/DNS setup
614 TODO: cross-connection