1wpa_supplicant and Wi-Fi P2P 2============================ 3 4This document describes how the Wi-Fi P2P implementation in 5wpa_supplicant can be configured and how an external component on the 6client (e.g., management GUI) is used to enable WPS enrollment and 7registrar registration. 8 9 10Introduction to Wi-Fi P2P 11------------------------- 12 13TODO 14 15More information about Wi-Fi P2P is available from Wi-Fi Alliance: 16http://www.wi-fi.org/Wi-Fi_Direct.php 17 18 19wpa_supplicant implementation 20----------------------------- 21 22TODO 23 24 25wpa_supplicant configuration 26---------------------------- 27 28Wi-Fi P2P is an optional component that needs to be enabled in the 29wpa_supplicant build configuration (.config). Here is an example 30configuration that includes Wi-Fi P2P support and Linux nl80211 31-based driver interface: 32 33CONFIG_DRIVER_NL80211=y 34CONFIG_CTRL_IFACE=y 35CONFIG_P2P=y 36CONFIG_AP=y 37CONFIG_WPS=y 38 39 40In run-time configuration file (wpa_supplicant.conf), some parameters 41for P2P may be set. In order to make the devices easier to recognize, 42device_name and device_type should be specified. For example, 43something like this should be included: 44 45ctrl_interface=/var/run/wpa_supplicant 46device_name=My P2P Device 47device_type=1-0050F204-1 48 49 50wpa_cli 51------- 52 53Actual Wi-Fi P2P operations are requested during runtime. These can be 54done for example using wpa_cli (which is described below) or a GUI 55like wpa_gui-qt4. 56 57 58wpa_cli starts in interactive mode if no command string is included on 59the command line. By default, it will select the first network interface 60that it can find (and that wpa_supplicant controls). If more than one 61interface is in use, it may be necessary to select one of the explicitly 62by adding -i argument on the command line (e.g., 'wpa_cli -i wlan1'). 63 64Most of the P2P operations are done on the main interface (e.g., the 65interface that is automatically added when the driver is loaded, e.g., 66wlan0). When using a separate virtual interface for group operations 67(e.g., wlan1), the control interface for that group interface may need 68to be used for some operations (mainly WPS activation in GO). This may 69change in the future so that all the needed operations could be done 70over the main control interface. 71 72Device Discovery 73 74p2p_find [timeout in seconds] [type=<social|progressive>] \ 75 [dev_id=<addr>] [dev_type=<device type>] \ 76 [delay=<search delay in ms>] 77 78The default behavior is to run a single full scan in the beginning and 79then scan only social channels. type=social will scan only social 80channels, i.e., it skips the initial full scan. type=progressive is 81like the default behavior, but it will scan through all the channels 82progressively one channel at the time in the Search state rounds. This 83will help in finding new groups or groups missed during the initial 84full scan. 85 86The optional dev_id option can be used to specify a single P2P peer to 87search for. The optional delay parameter can be used to request an extra 88delay to be used between search iterations (e.g., to free up radio 89resources for concurrent operations). 90 91The 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". 94 95p2p_listen [timeout in seconds] 96 97Start Listen-only state (become discoverable without searching for 98other devices). Optional parameter can be used to specify the duration 99for the Listen operation in seconds. This command may not be of that 100much use during normal operations and is mainly designed for 101testing. It can also be used to keep the device discoverable without 102having to maintain a group. 103 104p2p_stop_find 105 106Stop ongoing P2P device discovery or other operation (connect, listen 107mode). 108 109p2p_flush 110 111Flush P2P peer table and state. 112 113Group Formation 114 115p2p_prov_disc <peer device address> <display|keypad|pbc> [join|auto] 116 117Send P2P provision discovery request to the specified peer. The 118parameters for this command are the P2P device address of the peer and 119the desired configuration method. For example, "p2p_prov_disc 12002:01:02:03:04:05 display" would request the peer to display a PIN for 121us and "p2p_prov_disc 02:01:02:03:04:05 keypad" would request the peer 122to enter a PIN that we display. 123 124The optional "join" parameter can be used to indicate that this command 125is requesting an already running GO to prepare for a new client. This is 126mainly used with "display" to request it to display a PIN. The "auto" 127parameter can be used to request wpa_supplicant to automatically figure 128out whether the peer device is operating as a GO and if so, use 129join-a-group style PD instead of GO Negotiation style PD. 130 131p2p_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] 134 135Start P2P group formation with a discovered P2P peer. This includes 136optional group owner negotiation, group interface setup, provisioning, 137and establishing data connection. 138 139The <pbc|pin|PIN#> parameter specifies the WPS provisioning 140method. "pbc" string starts pushbutton method, "pin" string start PIN 141method using an automatically generated PIN (which will be returned as 142the command return code), PIN# means that a pre-selected PIN can be 143used (e.g., 12345670). [display|keypad] is used with PIN method 144to specify which PIN is used (display=dynamically generated random PIN 145from local display, keypad=PIN entered from peer display). "persistent" 146parameter can be used to request a persistent group to be formed. The 147"persistent=<network id>" alternative can be used to pre-populate 148SSID/passphrase configuration based on a previously used persistent 149group where this device was the GO. The previously used parameters will 150then be used if the local end becomes the GO in GO Negotiation (which 151can be forced with go_intent=15). 152 153"join" indicates that this is a command to join an existing group as a 154client. It skips the GO Negotiation part. This will send a Provision 155Discovery Request message to the target GO before associating for WPS 156provisioning. 157 158"auth" indicates that the WPS parameters are authorized for the peer 159device without actually starting GO Negotiation (i.e., the peer is 160expected to initiate GO Negotiation). This is mainly for testing 161purposes. 162 163"go_intent" can be used to override the default GO Intent for this GO 164Negotiation. 165 166"freq" can be used to set a forced operating channel (e.g., freq=2412 167to select 2.4 GHz channel 1). 168 169"provdisc" can be used to request a Provision Discovery exchange to be 170used prior to starting GO Negotiation as a workaround with some deployed 171P2P implementations that require this to allow the user to accept the 172connection. 173 174p2p_group_add [persistent|persistent=<network id>] [freq=<freq in MHz>] 175 [ht40] [vht] 176 177Set up a P2P group owner manually (i.e., without group owner 178negotiation with a specific peer). This is also known as autonomous 179GO. Optional persistent=<network id> can be used to specify restart of 180a persistent group. Optional freq=<freq in MHz> can be used to force 181the GO to be started on a specific frequency. Special freq=2 or freq=5 182options can be used to request the best 2.4 GHz or 5 GHz band channel 183to be selected automatically. 184 185p2p_reject <peer device address> 186 187Reject connection attempt from a peer (specified with a device 188address). This is a mechanism to reject a pending GO Negotiation with 189a peer and request to automatically block any further connection or 190discovery of the peer. 191 192p2p_group_remove <group interface> 193 194Terminate a P2P group. If a new virtual network interface was used for 195the group, it will also be removed. The network interface name of the 196group interface is used as a parameter for this command. 197 198p2p_cancel 199 200Cancel an ongoing P2P group formation and joining-a-group related 201operation. This operations unauthorizes the specific peer device (if any 202had been authorized to start group formation), stops P2P find (if in 203progress), stops pending operations for join-a-group, and removes the 204P2P group interface (if one was used) that is in the WPS provisioning 205step. If the WPS provisioning step has been completed, the group is not 206terminated. 207 208p2p_remove_client <peer's P2P Device Address|iface=<interface address>> 209 210This 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 212can rejoin the group if it is in possession of a valid key. See p2p_set 213per_sta_psk command below for more details on how the peer can be 214removed securely. 215 216Service Discovery 217 218p2p_serv_disc_req 219 220Schedule a P2P service discovery request. The parameters for this 221command are the device address of the peer device (or 00:00:00:00:00:00 222for wildcard query that is sent to every discovered P2P peer that 223supports service discovery) and P2P Service Query TLV(s) as hexdump. For 224example, 225 226p2p_serv_disc_req 00:00:00:00:00:00 02000001 227 228schedules a request for listing all available services of all service 229discovery protocols and requests this to be sent to all discovered 230peers (note: this can result in long response frames). The pending 231requests are sent during device discovery (see p2p_find). 232 233Only a single pending wildcard query is supported, but there can be 234multiple pending peer device specific queries (each will be sent in 235sequence whenever the peer is found). 236 237This command returns an identifier for the pending query (e.g., 238"1f77628") that can be used to cancel the request. Directed requests 239will be automatically removed when the specified peer has replied to 240it. 241 242Service Query TLV has following format: 243Length (2 octets, little endian) - length of following data 244Service Protocol Type (1 octet) - see the table below 245Service Transaction ID (1 octet) - nonzero identifier for the TLV 246Query Data (Length - 2 octets of data) - service protocol specific data 247 248Service Protocol Types: 2490 = All service protocols 2501 = Bonjour 2512 = UPnP 2523 = WS-Discovery 2534 = Wi-Fi Display 254 255For UPnP, an alternative command format can be used to specify a 256single query TLV (i.e., a service discovery for a specific UPnP 257service): 258 259p2p_serv_disc_req 00:00:00:00:00:00 upnp <version hex> <ST: from M-SEARCH> 260 261For example: 262 263p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1 264 265Additional examples for queries: 266 267# list of all Bonjour services 268p2p_serv_disc_req 00:00:00:00:00:00 02000101 269 270# list of all UPnP services 271p2p_serv_disc_req 00:00:00:00:00:00 02000201 272 273# list of all WS-Discovery services 274p2p_serv_disc_req 00:00:00:00:00:00 02000301 275 276# list of all Bonjour and UPnP services 277p2p_serv_disc_req 00:00:00:00:00:00 0200010102000202 278 279# Apple File Sharing over TCP 280p2p_serv_disc_req 00:00:00:00:00:00 130001010b5f6166706f766572746370c00c000c01 281 282# Bonjour SSTH (supported service type hash) 283p2p_serv_disc_req 00:00:00:00:00:00 05000101000000 284 285# UPnP examples 286p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 ssdp:all 287p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 upnp:rootdevice 288p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:service:ContentDirectory:2 289p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 uuid:6859dede-8574-59ab-9332-123456789012 290p2p_serv_disc_req 00:00:00:00:00:00 upnp 10 urn:schemas-upnp-org:device:InternetGatewayDevice:1 291 292# Wi-Fi Display examples 293# format: wifi-display <list of roles> <list of subelements> 294p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source] 2,3,4,5 295p2p_serv_disc_req 02:01:02:03:04:05 wifi-display [pri-sink] 3 296p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [sec-source] 2 297p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source+sink] 2,3,4,5 298p2p_serv_disc_req 00:00:00:00:00:00 wifi-display [source][pri-sink] 2,3,4,5 299 300p2p_serv_disc_cancel_req <query identifier> 301 302Cancel a pending P2P service discovery request. This command takes a 303single parameter: identifier for the pending query (the value returned 304by p2p_serv_disc_req, e.g., "p2p_serv_disc_cancel_req 1f77628". 305 306p2p_serv_disc_resp 307 308Reply to a service discovery query. This command takes following 309parameters: frequency in MHz, destination address, dialog token, 310response TLV(s). The first three parameters are copied from the 311request event. For example, "p2p_serv_disc_resp 2437 02:40:61:c2:f3:b7 3121 0300000101". This command is used only if external program is used 313to process the request (see p2p_serv_disc_external). 314 315p2p_service_update 316 317Indicate that local services have changed. This is used to increment 318the P2P service indicator value so that peers know when previously 319cached information may have changed. This is only needed when external 320service discovery processing is enabled since the commands to 321pre-configure services for internal processing will increment the 322indicator automatically. 323 324p2p_serv_disc_external <0|1> 325 326Configure external processing of P2P service requests: 0 (default) = 327no external processing of requests (i.e., internal code will process 328each request based on pre-configured services), 1 = external 329processing of requests (external program is responsible for replying 330to service discovery requests with p2p_serv_disc_resp). Please note 331that there is quite strict limit on how quickly the response needs to 332be transmitted, so use of the internal processing is strongly 333recommended. 334 335p2p_service_add bonjour <query hexdump> <RDATA hexdump> 336 337Add a local Bonjour service for internal SD query processing. 338 339Examples: 340 341# AFP Over TCP (PTR) 342p2p_service_add bonjour 0b5f6166706f766572746370c00c000c01 074578616d706c65c027 343# AFP Over TCP (TXT) (RDATA=null) 344p2p_service_add bonjour 076578616d706c650b5f6166706f766572746370c00c001001 00 345 346# IP Printing over TCP (PTR) (RDATA=MyPrinter._ipp._tcp.local.) 347p2p_service_add bonjour 045f697070c00c000c01 094d795072696e746572c027 348# IP Printing over TCP (TXT) (RDATA=txtvers=1,pdl=application/postscript) 349p2p_service_add bonjour 096d797072696e746572045f697070c00c001001 09747874766572733d311a70646c3d6170706c69636174696f6e2f706f7374736372797074 350 351# Supported Service Type Hash (SSTH) 352p2p_service_add bonjour 000000 <32-byte bitfield as hexdump> 353(note: see P2P spec Annex E.4 for information on how to construct the bitfield) 354 355p2p_service_del bonjour <query hexdump> 356 357Remove a local Bonjour service from internal SD query processing. 358 359p2p_service_add upnp <version hex> <service> 360 361Add a local UPnP service for internal SD query processing. 362 363Examples: 364 365p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::upnp:rootdevice 366p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::upnp:rootdevice 367p2p_service_add upnp 10 uuid:1122de4e-8574-59ab-9322-333456789044::urn:schemas-upnp-org:service:ContentDirectory:2 368p2p_service_add upnp 10 uuid:5566d33e-9774-09ab-4822-333456785632::urn:schemas-upnp-org:service:ContentDirectory:2 369p2p_service_add upnp 10 uuid:6859dede-8574-59ab-9332-123456789012::urn:schemas-upnp-org:device:InternetGatewayDevice:1 370 371p2p_service_del upnp <version hex> <service> 372 373Remove a local UPnP service from internal SD query processing. 374 375p2p_service_flush 376 377Remove all local services from internal SD query processing. 378 379Invitation 380 381p2p_invite [persistent=<network id>|group=<group ifname>] [peer=address] 382 [go_dev_addr=address] [freq=<freq in MHz>] [ht40] [vht] 383 [pref=<MHz>] 384 385Invite a peer to join a group (e.g., group=wlan1) or to reinvoke a 386persistent group (e.g., persistent=4). If the peer device is the GO of 387the persistent group, the peer parameter is not needed. Otherwise it is 388used to specify which device to invite. go_dev_addr parameter can be 389used to override the GO device address for Invitation Request should 390it be not known for some reason (this should not be needed in most 391cases). When reinvoking a persistent group, the GO device can specify 392the frequency for the group with the freq parameter. When reinvoking a 393persistent group, the P2P client device can use freq parameter to force 394a specific operating channel (or invitation failure if GO rejects that) 395or pref parameter to request a specific channel (while allowing GO to 396select to use another channel, if needed). 397 398Group Operations 399 400(These are used on the group interface.) 401 402wps_pin <any|address> <PIN> 403 404Start WPS PIN method. This allows a single WPS Enrollee to connect to 405the AP/GO. This is used on the GO when a P2P client joins an existing 406group. The second parameter is the address of the Enrollee or a string 407"any" to allow any station to use the entered PIN (which will restrict 408the PIN for one-time-use). PIN is the Enrollee PIN read either from a 409label or display on the P2P Client/WPS Enrollee. 410 411wps_pbc 412 413Start WPS PBC method (i.e., push the button). This allows a single WPS 414Enrollee to connect to the AP/GO. This is used on the GO when a P2P 415client joins an existing group. 416 417p2p_get_passphrase 418 419Get the passphrase for a group (only available when acting as a GO). 420 421p2p_presence_req [<duration> <interval>] [<duration> <interval>] 422 423Send a P2P Presence Request to the GO (this is only available when 424acting as a P2P client). If no duration/interval pairs are given, the 425request indicates that this client has no special needs for GO 426presence. The first parameter pair gives the preferred duration and 427interval values in microseconds. If the second pair is included, that 428indicates which value would be acceptable. This command returns OK 429immediately and the response from the GO is indicated in a 430P2P-PRESENCE-RESPONSE event message. 431 432Parameters 433 434p2p_ext_listen [<period> <interval>] 435 436Configure Extended Listen Timing. If the parameters are omitted, this 437feature is disabled. If the parameters are included, Listen State will 438be entered every interval msec for at least period msec. Both values 439have acceptable range of 1-65535 (with interval obviously having to be 440larger than or equal to duration). If the P2P module is not idle at 441the time the Extended Listen Timing timeout occurs, the Listen State 442operation will be skipped. 443 444The configured values will also be advertised to other P2P Devices. The 445received values are available in the p2p_peer command output: 446 447ext_listen_period=100 ext_listen_interval=5000 448 449p2p_set <field> <value> 450 451Change dynamic P2P parameters 452 453p2p_set discoverability <0/1> 454 455Disable/enable advertisement of client discoverability. This is 456enabled by default and this parameter is mainly used to allow testing 457of device discoverability. 458 459p2p_set managed <0/1> 460 461Disable/enable managed P2P Device operations. This is disabled by 462default. 463 464p2p_set listen_channel <1/6/11> 465 466Set P2P Listen channel. This is mainly meant for testing purposes and 467changing the Listen channel during normal operations can result in 468protocol failures. 469 470p2p_set ssid_postfix <postfix> 471 472Set postfix string to be added to the automatically generated P2P SSID 473(DIRECT-<two random characters>). For example, postfix of "-testing" 474could result in the SSID becoming DIRECT-ab-testing. 475 476p2p_set per_sta_psk <0/1> 477 478Disabled(default)/enables use of per-client PSK in the P2P groups. This 479can be used to request GO to assign a unique PSK for each client during 480WPS provisioning. When enabled, this allow clients to be removed from 481the group securily with p2p_remove_client command since that client's 482PSK is removed at the same time to prevent it from connecting back using 483the old PSK. When per-client PSK is not used, the client can still be 484disconnected, but it will be able to re-join the group since the PSK it 485learned previously is still valid. It should be noted that the default 486passphrase on the GO that is normally used to allow legacy stations to 487connect through manual configuration does not change here, so if that is 488shared, devices with knowledge of that passphrase can still connect. 489 490set <field> <value> 491 492Set global configuration parameters which may also affect P2P 493operations. The format on these parameters is same as is used in 494wpa_supplicant.conf. Only the parameters listen here should be 495changed. Modifying other parameters may result in incorrect behavior 496since not all existing users of the parameters are updated. 497 498set uuid <UUID> 499 500Set WPS UUID (by default, this is generated based on the MAC address). 501 502set device_name <device name> 503 504Set WPS Device Name (also included in some P2P messages). 505 506set manufacturer <manufacturer> 507 508Set WPS Manufacturer. 509 510set model_name <model name> 511 512Set WPS Model Name. 513 514set model_number <model number> 515 516Set WPS Model Number. 517 518set serial_number <serial number> 519 520Set WPS Serial Number. 521 522set device_type <device type> 523 524Set WPS Device Type. 525 526set os_version <OS version> 527 528Set WPS OS Version. 529 530set config_methods <config methods> 531 532Set WPS Configuration Methods. 533 534set sec_device_type <device type> 535 536Add a new Secondary Device Type. 537 538set p2p_go_intent <GO intent> 539 540Set the default P2P GO Intent. Note: This value can be overridden in 541p2p_connect command and as such, there should be no need to change the 542default value here during normal operations. 543 544set p2p_ssid_postfix <P2P SSID postfix> 545 546Set P2P SSID postfix. 547 548set persistent_reconnect <0/1> 549 550Disable/enabled persistent reconnect for reinvocation of persistent 551groups. If enabled, invitations to reinvoke a persistent group will be 552accepted without separate authorization (e.g., user interaction). 553 554set country <two character country code> 555 556Set country code (this is included in some P2P messages). 557 558Status 559 560p2p_peers [discovered] 561 562List P2P Device Addresses of all the P2P peers we know. The optional 563"discovered" parameter filters out the peers that we have not fully 564discovered, i.e., which we have only seen in a received Probe Request 565frame. 566 567p2p_peer <P2P Device Address> 568 569Fetch information about a known P2P peer. 570 571Group Status 572 573(These are used on the group interface.) 574 575status 576 577Show status information (connection state, role, use encryption 578parameters, IP address, etc.). 579 580sta 581 582Show information about an associated station (when acting in AP/GO role). 583 584all_sta 585 586Lists the currently associated stations. 587 588Configuration data 589 590list_networks 591 592Lists the configured networks, including stored information for 593persistent groups. The identifier in this list is used with 594p2p_group_add and p2p_invite to indicate which persistent group is to 595be reinvoked. 596 597remove_network <network id> 598 599Remove a network entry from configuration. 600 601 602wpa_cli action script 603--------------------- 604 605See examples/p2p-action.sh 606 607TODO: describe DHCP/DNS setup 608TODO: cross-connection 609