This functionality could be shared for other commands, too, so move
it to a common function. In addition, implement the validation in a
bit more strict way to avoid accepting values like '-123' as a valid
PIN.
Signed-hostap: Jouni Malinen <j@w1.fi>
The new hostapd ctrl_iface command WPS_NFC_TOKEN can now be used to
manage AP-as-Enrollee operations with NFC password token. WPS/NDEF
parameters to this command can be used to generate a new NFC password
token. enable/disable parameters can be used to enable/disable use of
NFC password token (instead of AP PIN) for external Registrars.
A preconfigured NFS password token can be used by providing its
parameters with new hostapd.conf fields wps_nfc_dev_pw_id,
wps_nfc_dh_pubkey, wps_nfc_dh_privkey, and wps_nfc_dev_pw. This use
will also depend on WPS_NFC_TOKEN enable/disable commands, i.e., the
configured NFS password token is disabled by default.
Signed-hostap: Jouni Malinen <j@w1.fi>
WPS_ER_NFC_CONFIG_TOKEN command can now be used to build a NFC
configuration token based on AP Settings learnt with WPS_ER_LEARN
or set with WPS_ER_CONFIG.
Signed-hostap: Jouni Malinen <j@w1.fi>
The new wpa_supplicant ctrl_iface command WPS_NFC_TAG_READ can now be
used to process NFC tags read by external programs to initiate
wpa_supplicant to use NFC Configuration Token to create a new network.
Signed-hostap: Jouni Malinen <j@w1.fi>
The new hostapd ctrl_iface command WPS_NFC_CONFIG_TOKEN can now be used
to fetch payload for an NFC configuration token so that an external
program can be used to write this on an NFC tag.
Signed-hostap: Jouni Malinen <j@w1.fi>
This adds a cleaner mechanism for handling NFC Password Tokens in the
WPS Registrar. There could be more than one active NFC Password Token in
use and as such, a list of tokens needs to be maintained. The old
WPS_OOB interface is still using the old mechanism that supports only a
single active NFC Password Token.
Signed-hostap: Jouni Malinen <j@w1.fi>
hostapd ctrl_iface can now be used to deliver payload from read
operation of an NFC tag. This allows operations without having to have
low-level NFC code within hostapd. For now, the new wps_nfc_tag_read
command can be used with NFC password tokens for the case where the AP
has an NFC device that is used to read an NFC tag from the station
Enrollee.
Signed-hostap: Jouni Malinen <j@w1.fi>
Instead of requiring low-level access to an NFC device and synchronous
operations, the new WPS_NFC_TOKEN and WPS_NFC ctrl_iface commands can be
used to build a NFC password token and initiate WPS protocol run using
that token (or pre-configured values) as separate commands. The
WPS_NFC_TOKEN output can be written to a NFC tag using an external
program, i.e., wpa_supplicant does not need to have low-level code for
NFC operations for this.
Signed-hostap: Jouni Malinen <j@w1.fi>
Previously, only the maximum length 32 octets for OOB device password
was accepted. Since the specification allows a shorter password to be
used with limited OOB mechanism (e.g., small NFC tag), we should accept
lengths 16..32.
Signed-hostap: Jouni Malinen <j@w1.fi>
The earlier WPS 2.0 changes did not increase the wpabuf size when
adding a new attribute to the NFC password token. This could result
in aborting the application on wpabuf overflow if NFC out-of-band
mechanism is used with WPS 2.0 enabled.
Signed-hostap: Jouni Malinen <j@w1.fi>
intended-for: hostap-1
In AP which supports WPSv2 with only virtual push button, when PBC is
called, the WSC IE should include Selected Registrar Configuration
Methods attribute with the bit of the physical push button not set.
Signed-hostap: Yoni Divinsky <yoni.divinsky@ti.com>
wps_vendor_ext_m1 configuration parameter can now be used to add a
vendor specific attribute into the WPS M1 message, e.g., for
Windows Vertical Pairing.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
If a wildcard PIN is used on any of the radios that hostapd is
controlling, invalidate the matching PIN on all the other radios
to avoid multiple uses of the same PIN.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Use Device Password ID in WSC IE of Probe Request and Probe Response
frames to advertise immediate availability of WPS credentials per P2P
specification sections 3.1.2.1.1 (Listen State), 3.1.2.1.2 (Scan Phase),
and 3.1.2.1.3 (Find Phase).
For now, the Device Password ID is set only for the case where we are
active GO Negotiation with a specific peer. In practice, this means that
the Probe Response frames during pending GO Negotiation (whenever in
Listen state) indicate availability of the credential.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Remove unnecessary second copy of the URL and too long memory
allocation. In addition, avoid use of strcpy() to keep static analyzers
happier.
Signed-hostap: Jouni Malinen <j@w1.fi>
The SetSelectedRegistrar timeout was registered for each registrar
instance, but the only context pointer (struct subscription *) was
shared with each registrar which resulted in the timeout getting
cancelled for some of the registrar instances before the selected
registrar (ER) information was cleared.
In addition, when an ER unsubscribed from receiving events, the
selected registrar information got cleared only from a single
registrar.
Fix these issues by registering a pointer to the registrar
instance in the timeout and by iterating over all UPnP interfaces
when removing a subscription.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Remove the GPL notification text from files that were initially
contributed by Atheros Communications or Qualcomm Atheros.
Signed-hostap: Jouni Malinen <j@w1.fi>
Previously, PINs that are added with a wildcard UUID were allowed to
be used only by a single Enrollee. However, there may be more than one
Enrollee trying to connect when an AP indicates that active Registrar
is present. As a minimal workaround, allow two Enrollees to try to use
the wildcard PIN. More complete extension could use timeout and allow
larger set of Enrollees to try to connect (while still keeping in mind
PIN disabling requirement after 10 failed attempts).
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
While the exponential increase in the lockout period provides an
efficient mitigation mechanism against brute force attacks, this
additional trigger to enter indefinite lockout period (cleared by
restarting hostapd) will limit attacks even further by giving maximum of
10 attempts (without authorized user action) even in a very long term
attack.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
It looks like Windows 7 WPS implementation does not like multiple
Authentication/Encryption Type bits to be set in M7 AP Settings
attributes, i.e., it refused to add a network profile if the AP
was configured for WPA/WPA2 mixed mode and AP PIN was used to
enroll the network.
Leave only a single bit set in the Authentication/Encryption Type
attributes in M7 when the AP is acting as an Enrollee to avoid this
issue.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Since wps_registrar_pbc_timeout is called to stop PBC, previously
registered wps_registrar_pbc_timeout must be canceled when canceling
the WPS operation.
Signed-off-by: Spencer Chang <jungwalk@gmail.com>
WPS overlap detection can detect false overlap if a P2P peer
changes UUID while authentication is ongoing. Changing UUID
is of course wrong but this is what some popular devices do
so we need to work around it in order to keep compatibility
with these devices. There already is a mechanism in WPS
registrar to skip overlap detection if P2P addresses of two
sessions match but it wasn't really triggered because the
address wasn't filled in in the caller function.
Let's fill in this address and also clean up WPS PBC sessions
on WSC process completion if UUID was changed.
Signed-hostap: Vitaly Wool<vitalywool@gmail.com>
When hostapd controls multiple radios, WPS operations are started on
all interfaces. However, when the provisioning run had been completed
successfully, actiove WPS mode was stopped only a single interface. Fix
this to iterate through all interfaces so that this is handled
consistently with the starting of WPS operation.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Commit 628d54639a introduced number
of new WPS related ctrl_iface messages to hostapd. Some of these
were for ER events which do not make any sense to hostapd that
cannot operate as an ER. The WPS_EV_ER_SET_SELECTED_REGISTRAR one
from wps_registrar_sel_registrar_changed_event() was especially
problematic since it can cause wpa_supplicant ER code segfault due
to missing event data.
Revert all the ER specific changes from commit
628d54639a to get rid of the segfault
and undesired extra code in hostapd.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Some static analyzers complain about memset with '0' value. This was
used correctly here, but since use of strdup is about as good an option,
use that to silence the invalid warnings.
Signed-hostap: Jouni Malinen <j@w1.fi>
When the supplicant acts as a registrar to learn the access point
parameters send the credentials to the wpa_cli interface after
receiving the 7th message. This is needed for proper behavior with
wps_cred_processing set to 1 or 2.
Without this patch, after the 7th message you got the WPS-CRED-RECEIVED
notification without the credentials. This was because the cred_attr and
cred_attr_len were not filled in in the wps structure.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Wrap self-generated WPS credential for new AP settings and send that to
control interface to provide the needed information in
WPS-NEW-AP-SETTINGS for external processing.
os_*() wrappers should be used instead of functions from time.h.
Removing the header from includes.h enforces this. os_unix.c can
include this its uses are valid wrapper calls. wps_upnp.c uses
gmtime() for which there is no os_*() wrapper available yet, so
allow it to use time.h, too. Similarly, allow dump_state.c to
use time.h for ctime().
Instead of hardcoding the Config Methods attribute value in Probe
Request frames, set this based on the configured parameter
config_methods to allow correct set of methods to be advertised.
The device description file may include multiple devices. Improve the
simplistic parser by first trying to find the WFADevice:1 device before
fetching the device parameters. While this is still far from complete
XML parsing, this should address the most common root device
specifications.
Extend the code that waits for the station to send EAPOL-Start before
initiating EAPOL authenticator operations to cover the case where the
station includes WPS IE in (Re)Association Request frame if that IE
does not include support for WPS 2.0. While this should not really
be needed, this may help with some deployed WPS 1.0 stations that do
not support EAPOL operations correctly and may get confused of the
EAP-Request/Identity packets that would show up twice if EAPOL-Start
is transmitted.
The Config Methods attribute in M2 and M2D messages is supposed to
indicate which configuration methods are supported by the Registrar. As
such, it should not depend on whether PBC mode is currently active or
not. That will only affect the Selected Registrar Config Methods and
Device Password ID attributes.
Windows 7 uses incorrect way of figuring out AP's WPS capabilities by
acting as a Registrar and using M1 from the AP. The config methods
attribute in that message is supposed to indicate only the configuration
method supported by the AP in Enrollee role, i.e., to add an external
Registrar. For that case, PBC shall not be used and as such, the
PushButton config method is removed from M1 by default. If pbc_in_m1=1
is included in the configuration file, the PushButton config method is
left in M1 (if included in config_methods parameter) to allow Windows 7
to use PBC instead of PIN (e.g., from a label in the AP).
Make the P2P code keep track of WPS vendor extensions received from
peers so they can be exposed via DBus later.
Signed-off-by: Jean-Michel Bachot <jean-michelx.bachot@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This adds the ability to add WPS vendor extensions to an AP (or GO).
They will be added to the WSC IE(s) in Beacon and Probe Response frames.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Use only the UUID-E to remove active PBC session(s) at the completion of
successful PBC protocol run. This fixes potential issues with Enrollees
that use multiple MAC addresses and as such, can get multiple entries in
the PBC session list.
The secondary device type list is an optional attribute in the WSC IE.
Signed-off-by: Jean-Michel Bachot <jean-michelx.bachot@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Use a specific return value, WPS-PBC-OVERLAP, to indicate a reason
for rejecting a wps_pbc command in wpa_supplicant AP mode if the
PBC mode cannot be started due to PBC session overlap having been
detected during monitor time.
This allows the user to complete WPS provisioning using PBC by
selected a specific Enrollee even if there are other Enrollees
in active PBC mode at the same time. The other Enrollees will be
rejected should they try to connect at the same time.
Ignore possible mismatches in the source address of the frame and only
use UUID-E to check whether a Probe Request or M1 is from the same
Enrollee when figuring out whether there is PBC session overlap. This
is needed to avoid potential issues with Enrollee devices that may have
multiple interfaces indicating active PBC state.
An optional parameter, p2p_dev_addr, can now be given to WPS_PBC
command on P2P GO to indicate that only the P2P device with the
specified P2P Device Address is allowed to connect using PBC. If
any other device tries to use PBC, a session overlap is indicated
and the negotiation is rejected with M2D. The command format for
specifying the address is "WPS_PBC p2p_dev_addr=<address>", e.g.,
WPS_PBC p2p_dev_addr=02:03:04:05:06:07
In addition, show the PBC session overlap indication as a WPS failure
event on an AP/GO interface. This particular new case shows up as
"WPS-FAIL msg=4 config_error=12".
Previously, only the Configuration Error values were indicated in
WPS-FAIL events. Since those values are defined in the specification
it is not feasible to extend them for indicating other errors. Add
a new error indication value that is internal to wpa_supplicant and
hostapd to allow other errors to be indicated.
Use the new mechanism to indicate if negotiation fails because of
WEP or TKIP-only configurations being disallows by WPS 2.0.
This commit adds a new wrapper, random_get_bytes(), that is currently
defined to use os_get_random() as is. The places using
random_get_bytes() depend on the returned value being strong random
number, i.e., something that is infeasible for external device to
figure out. These values are used either directly as a key or as
nonces/challenges that are used as input for key derivation or
authentication.
The remaining direct uses of os_get_random() do not need as strong
random numbers to function correctly.
ap_setup_locked=2 can now be used to enable a special mode where
WPS ER can learn the current AP settings, but cannot change then.
In other words, the protocol is allowed to continue past M2, but
is stopped at M7 when AP is in this mode. WPS IE does not
advertise AP Setup Locked in this case to avoid interoperability
issues.
In wpa_supplicant, use ap_setup_locked=2 by default. Since the AP PIN
is disabled by default, this does not enable any new functionality
automatically. To allow the read-only ER to go through the protocol,
wps_ap_pin command needs to be used to enable the AP PIN.
When multiple wireless interfaces are used with WPS, the UPnP
subscriptions need to be removed whenever a matching Registrar
instance gets removed. This avoids a segfault due to access to
freed memory during hostapd shutdown.
In addition, the UPnP interface instance structure needs to be
freed to avoid memory leak.
WPS external Registrars can get confused about multiple UPnP
instances (one per radio) on a dual-concurrent APs. Simplify the
design by sharing a single UPnP state machine for all wireless
interfaces controlled by hostapd. This matches with the previous
changes that made a single command enable WPS functionality on
all interfaces.
This is relatively minimal change to address the sharing of the
state among multiple struct hostapd_data instances. More cleanup
can be done separately to remove unnecessary copies of information.
This is needed to avoid issues with APs that restart their UPnP,
e.g., when ER reconfigures them. The previously known settings are
now cached and taken into use if an AP is detected to leave
(ssdp:byebye) and then return.
Verify that the UUID given to wps_er_pbc command is known and only
activate PBC mode on the matching AP. The UUID can be that of the
AP or the station/Enrollee.
This command can be used to enroll a network based on a local
network configuration block instead of having to (re-)learn the
current AP settings with wps_er_learn.
UPnP event subscriptions are not supposed to be dropped based on
whether events can be delivered quickly enough. Leave dropping to
happen only based on failed deliveries to avoid issues with a burst
of events kicking out still active subscribers.
Do not send more than five Probe Request WLANEvent notifications
per second. Even though the limit should in theory apply to all
WLANEvents, it is better not to drop EAP notifications because
of Probe Request frames and really, the only real reason for
event bursts is Probe Request frames.
Instead of queuing all events for a subscriber, only queue more
important events if delivery of event notifications starts failing.
This allows more time for the subscriber to recover since the maximum
queue length if not reached because of Probe Request frames only.
Instead of dropping the subscription on first failure, allow up to
10 failures before dropping. In addition, drop the callback URLs
one by one instead of full subscription if only one URL is failing.
This makes it easier to figure out what could have failed in the
WPS protocol and potentially provide more information for the
user on how to resolve the issue.
At least D-Link DIR-600 and DIR-825 have been reported to include
an extra octet after the Network Key attribute within a Credential
attribute. This can happen at least when they are provisioning an
open network.
Add a workaround to detect this incorrectly encoded attribute and
to skip the extra octet when parsing such a Credential.
We need to clear the selected registrar timeout from wps_er_learn
when stopping the protocol run at M7 (previously, this was done only
when WSC_Done was being processed). In addition, we need to cancel
the timeout when a new PBC operation is started.
Need to figure out whether the message is from a WSC 2.0 -based
device based on the unencrypted attributes, not the contents of the
encrypted data since the Version2 subelement is only included in the
unencrypted area.
Instead of build time options (CONFIG_WPS_TESTING_EXTRA_CRED and
CONFIG_WPS_EXTENSIBILITY_TESTING), use a single build option
(CONFIG_WPS_TESTING) and runtime configuration of which testing
operations are enabled. This allows a single binary to be used
for various tests.
The runtime configuration can be done through control interface
with wpa_cli/hostapd_cli commands:
Enable extensibility tests:
set wps_version_number 0x57
Disable extensibility tests (WPS2 build):
set wps_version_number 0x20
Enable extra credential tests:
set wps_testing_dummy_cred 1
Disable extra credential tests:
set wps_testing_dummy_cred 0
The Beacon frame must include UUID-E and RF Bands attributes when
in active PBC mode to allow stations to figure out that two BSSes in
PBC mode is not a PBC session overlap.
A new ctrl_interface command, WPS_CANCEL, can now be used to cancel
a pending or ongoing WPS operation. For now, this is only available
with wpa_supplicant (either in station or AP mode). Similar
functionality should be added for hostapd, too.
The WSC 2.0 specification moved to use another design for the new
attributes to avoid backwards compatibility issues with some
deployed implementations.
If CONFIG_WPS_STRICT is set, validate WPS IE(s) in management frames and
reject the frames if any of the mandatory attributes is missing or if an
included attribute uses an invalid value. In addition, verify that all
mandatory attributes are included and have valid values in the WSC
messages.
If all the device information attributes use their maximum lengths,
a single WPS IE is not enough to fit in all the data and as such,
we must be able to fragment the data. In addition, the wpabuf needs
to be allocated larger to fit in maximum data.
Instead of using 0x00 as the extra character, use space (' ') to
avoid failing tests that verify that the variable length string
attributes are not null terminated. In addition, this workaround
can now be disabled by defining CONFIG_WPS_STRICT for the build.
This can be done by adding following line to .config:
CFLAGS += -DCONFIG_WPS_STRICT
However, it should be noted that such a build may not interoperate
with some deployed WPS 1.0 -based implementations and as such, is
mainly designed for testing.
Whenever wpa_supplication is using Request Type Enrollee, it is trying
to enroll into a network. Indicate this with the explicit inclusion of
Request to Enroll attribute with value TRUE.
Advertize list of authorized enrollee MAC addresses in Beacon and
Probe Response frames and use these when selecting the AP. In order
to provide the list, the enrollee MAC address should be specified
whenever adding a new PIN. In addition, add UUID-R into
SetSelectedRegistrar action to make it potentially easier for an AP
to figure out which ER sent the action should there be multiple ERs
using the same IP address.
This adds definitions and parsing of the new attributes that were added
in WPS 2.0. In addition, the version negotiation is updated to use the
new mechanism, i.e., accept everything received and use the new Version2
attribute in transmitted messages.
There is no need to process the public key and generate keys if
the AP is going to reject this M2 anyway. This limits effect of
potential CPU DoS attacks in cases where AP PIN is disabled.
A new hostapd_cli command, wps_ap_pin, can now be used to manage
AP PIN at runtime. This can be used to generate a random AP PIN and
to only enable the AP PIN for short period (e.g., based on user
action on the AP device). Use of random AP PIN that is only enabled
for short duration is highly recommended to avoid security issues
with a static AP PIN.
This can happen on the AP if the AP PIN is not configured and
the client tries to go through the protocol instead of just using
Registrar mode to receive M1 from the AP. It is cleaner to send
out the WSC_NACK instead of just stopping the protocol.
In theory, this should not really be needed, but Windows 7 uses
Registrar mode to probe AP's WPS capabilities before trying to use
Enrollee and fails if the AP does not allow that probing to happen.
This allows the AP to start as an Enrollee and send M1, but refuse
to continue beyond that (M3 will not be sent if AP PIN is not known).
It looks like 10.6.3 and 10.6.4 do not like to receive Network Key
with WPA passphrase while PSK format still works. Use peer information
from M1 to figure out whether the Enrollee is likely to be OS X and
if so, force PSK format to be used for Network Key.
The AP configuration may change after provisioning, so it is better
not to use the current security policy to prioritize results. Instead,
use WPS Selected Registrar attribute as the main sorting key and use
signal strength next without considering security policy or rate sets.
The non-WPS provisioning case remains as-is, i.e., this change applies
only when trying to find an AP for WPS provisioning.
Some deployed implementations do not include the mandatory Network
Key attribute when a WPS Credential is for an open network. Allow
this to improve interoperability since the actual key value is not
really needed for open networks.
wps_er_config can now be used to configure an AP. It is similar to
wps_er_learn, but instead of only learning the current AP settings,
it continues to send M8 with the new settings for the AP.
wps_er_start command now takes an optional parameter that can be used
to configure a filter to only allow UPnP SSDP messages from the
specified IP address. In practice, this limits the WPS ER operations
to a single AP and filters out all other devices in the network.
When starting the protocol run with an Enrollee, clone the AP Settings
and replace the AP MAC Address with the Enrollee MAC Address so that the
correct value is then used in the Credential attribute in M8.
If the associating station indicates that it is intents to use WPS
by including WPS IE in (Re)Association Request frame, include WPS IE
in (Re)Association Response frame.
There are no subdirectories in any of these directories or plans
for adding ones. As such, there is no point in running the loop
that does not do anything and can cause problems with some shells.
Some ER implementation (e.g., some versions of Intel PROSet) seem to
use incorrect format for WLANEventMAC variable in PutWLANResponse.
Work around this by allowing various MAC address formats to be used
in this variable (debug message will be shown if the colon-deliminated
format specified in WFA WLANConfig 1.0 is not used).
This avoids conflict with both Label and Display being included at
the same time (which would make it difficult to figure out which
PIN was actually used).
This attribute is supposed to indicate which methods the AP supports as
an Enrollee for adding external Registrars. It was left to 0 when the
AP code did not yet support external Registrars and was forgotten when
the ER support was added.
This patch allows wpa_supplicant to compile on Debian's kfreebsd
architectures.
Patch by Stefan Lippers-Hollmann based on work done by Petr Salinger
and Emmanuel Bouthenot for 0.6.X (http://bugs.debian.org/480572).
WPS IE parsing for PBC mode did not check whether the UUID-E attribute
was included before dereferencing the pointer. This could result in the
AP crashing when processing and invalid Probe Request frame.
Skip WPS IE building for Beacon and Probe Response frames is set_ie_cb()
is not set. This fixes a memory leak and optimizes operations by not
allocating memory and building the WPS IEs unnecessarily.
set_ap_wps_ie() is not used to set WPS IE for both Beacon and Probe
Response frames with a single call. In addition, struct wpabuf is used
instead of separate u8* and length fields. This avoids duplicated
allocation of the IEs and simplifies code in general.
This adds config_methods configuration option for wpa_supplicant
following the design used in hostapd. In addition, the string is
now parsed in common code from src/wps/wps_common.c and the list
of configurable methods include all the defined methods from
WPS 1.0h spec.
Since an Enrollee that does not advertise display as one of the
Config Methods is unlikely to be able to show the ASCII passphrase
to the user, prefer PSK format with such an Enrollee to reduce key
derivation time. This can help with some low-powered devices that
would take long time to derive the PSK from the passphrase.
The use_psk_key parameter can now be used to force the Registrar to
use PSK format instead of ASCII passphrase when building a Credential
for the Enrollee. For now, this is not enabled, but it could be enabled
either based on external (to WPS) configuration or automatically set
based on some WPS attribute values from the Enrollee.
Instead of forcefully deinitializing ER immediately, give it some
time to complete unsubscription and call eloop_terminate() only once
ER code has completed its work.
Instead of using the latest selected registrar change, collect selected
registrar information separately from all registrars and use the union
of this information when building the WPS IE for Beacon and Probe
Response frames.
Note: SetSelectedRegistrar UPnP action does not include a unique
identifier, so the ER matching routine is based only on the IP address
of the ER. In theory, there could be multiple ERs using the same IP
address (but different port or URL), so there may be some corner cases
that would not always match the correct ER entry at the AP. Anyway, this
is not really expected to occur in normal use cases and even if it did
happen, the selected registrar information is not any worse than it was
before when only the last change from any registrar for being
advertized.
This is more logical location for checking the URL and potentially
handling a call to another URL handler. In addition, return 404 error,
not invalid UPnP action, if the URL does not match.
These callbacks can be handled internally within core WPS code, so there
is no need to go through wps_hostapd.c with a callback function that is
just calling back into the core WPS code.
