cfg80211: add peer measurement with FTM initiator API

Add a new "peer measurement" API, that can be used to measure
certain things related to a peer. Right now, only implement
FTM (flight time measurement) over it, but the idea is that
it'll be extensible to also support measuring the necessary
things to calculate e.g. angle-of-arrival for WiGig.

The API is structured to have a generic list of peers and
channels to measure with/on, and then for each of those a
set of measurements (again, only FTM right now) to perform.

Results are sent to the requesting socket, including a final
complete message.

Closing the controlling netlink socket will abort a running
measurement.

v3:
 - add a bit to report "final" for partial results
 - remove list keeping etc. and just unicast out the results
   to the requester (big code reduction ...)
 - also send complete message unicast, and as a result
   remove the multicast group
 - separate out struct cfg80211_pmsr_ftm_request_peer
   from struct cfg80211_pmsr_request_peer
 - document timeout == 0 if no timeout
 - disallow setting timeout nl80211 attribute to 0,
   must not include attribute for no timeout
 - make MAC address randomization optional
 - change num bursts exponent default to 0 (1 burst, rather
   rather than the old default of 15==don't care)

v4:
 - clarify NL80211_ATTR_TIMEOUT documentation

v5:
 - remove unnecessary nl80211 multicast/family changes
 - remove partial results bit/flag, final is sufficient
 - add max_bursts_exponent, max_ftms_per_burst to capability
 - rename "frames per burst" -> "FTMs per burst"

v6:
 - rename cfg80211_pmsr_free_wdev() to cfg80211_pmsr_wdev_down()
   and call it in leave, so the device can't go down with any
   pending measurements

v7:
 - wording fixes (Lior)
 - fix ftm.max_bursts_exponent to allow having the limit of 0 (Lior)

v8:
 - copyright statements
 - minor coding style fixes
 - fix error path leak

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 5bd01058b9e6..0a3092c56b3e 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -4,6 +4,7 @@
  * Copyright 2006-2010		Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright 2015-2017	Intel Deutschland GmbH
+ * Copyright (C) 2018 Intel Corporation
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -664,6 +665,34 @@ int wiphy_register(struct wiphy *wiphy)
 		return -EINVAL;
 #endif
 
+	if (WARN_ON(wiphy->pmsr_capa && !wiphy->pmsr_capa->ftm.supported))
+		return -EINVAL;
+
+	if (wiphy->pmsr_capa && wiphy->pmsr_capa->ftm.supported) {
+		if (WARN_ON(!wiphy->pmsr_capa->ftm.asap &&
+			    !wiphy->pmsr_capa->ftm.non_asap))
+			return -EINVAL;
+		if (WARN_ON(!wiphy->pmsr_capa->ftm.preambles ||
+			    !wiphy->pmsr_capa->ftm.bandwidths))
+			return -EINVAL;
+		if (WARN_ON(wiphy->pmsr_capa->ftm.preambles &
+				~(BIT(NL80211_PREAMBLE_LEGACY) |
+				  BIT(NL80211_PREAMBLE_HT) |
+				  BIT(NL80211_PREAMBLE_VHT) |
+				  BIT(NL80211_PREAMBLE_DMG))))
+			return -EINVAL;
+		if (WARN_ON(wiphy->pmsr_capa->ftm.bandwidths &
+				~(BIT(NL80211_CHAN_WIDTH_20_NOHT) |
+				  BIT(NL80211_CHAN_WIDTH_20) |
+				  BIT(NL80211_CHAN_WIDTH_40) |
+				  BIT(NL80211_CHAN_WIDTH_80) |
+				  BIT(NL80211_CHAN_WIDTH_80P80) |
+				  BIT(NL80211_CHAN_WIDTH_160) |
+				  BIT(NL80211_CHAN_WIDTH_5) |
+				  BIT(NL80211_CHAN_WIDTH_10))))
+			return -EINVAL;
+	}
+
 	/*
 	 * if a wiphy has unsupported modes for regulatory channel enforcement,
 	 * opt-out of enforcement checking
@@ -1087,6 +1116,8 @@ void __cfg80211_leave(struct cfg80211_registered_device *rdev,
 	ASSERT_RTNL();
 	ASSERT_WDEV_LOCK(wdev);
 
+	cfg80211_pmsr_wdev_down(wdev);
+
 	switch (wdev->iftype) {
 	case NL80211_IFTYPE_ADHOC:
 		__cfg80211_leave_ibss(rdev, dev, true);
@@ -1174,6 +1205,9 @@ void cfg80211_init_wdev(struct cfg80211_registered_device *rdev,
 	spin_lock_init(&wdev->event_lock);
 	INIT_LIST_HEAD(&wdev->mgmt_registrations);
 	spin_lock_init(&wdev->mgmt_registrations_lock);
+	INIT_LIST_HEAD(&wdev->pmsr_list);
+	spin_lock_init(&wdev->pmsr_lock);
+	INIT_WORK(&wdev->pmsr_free_wk, cfg80211_pmsr_free_wk);
 
 	/*
 	 * We get here also when the interface changes network namespaces,