[PATCH] nl80211: report age of bss entry from boot in microseconds

[Dmitry Shmidt]

    User-space needs to know real time from boot (including suspend)
    of bss entry for location and connectivity services.

Change-Id: I7d5db4378d7941ccecf8ac675425024c2aafe62b
Signed-off-by: Dmitry Shmidt <dimitr...@google.com>
---
 include/uapi/linux/nl80211.h | 2 ++
 net/wireless/core.h          | 1 +
 net/wireless/nl80211.c       | 3 ++-
 net/wireless/scan.c          | 3 +++
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index c0ab6b0..173b6a5 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -3364,6 +3364,7 @@ enum nl80211_bss_scan_width {
  * (not present if no beacon frame has been received yet)
  * @NL80211_BSS_PRESP_DATA: the data in @NL80211_BSS_INFORMATION_ELEMENTS and
  * @NL80211_BSS_TSF is known to be from a probe response (flag attribute)
+ * @NL80211_BSS_LAST_SEEN_BOOTTIME: age of this BSS entry in us from boot
  * @__NL80211_BSS_AFTER_LAST: internal
  * @NL80211_BSS_MAX: highest BSS attribute
  */
@@ -3383,6 +3384,7 @@ enum nl80211_bss {
  NL80211_BSS_CHAN_WIDTH,
  NL80211_BSS_BEACON_TSF,
  NL80211_BSS_PRESP_DATA,
+ NL80211_BSS_LAST_SEEN_BOOTTIME,

  /* keep last */
  __NL80211_BSS_AFTER_LAST,
diff --git a/net/wireless/core.h b/net/wireless/core.h
index b9d5bc8..261e159 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -140,6 +140,7 @@ struct cfg80211_internal_bss {
  unsigned long ts;
  unsigned long refcount;
  atomic_t hold;
+ u64 tfb;

  /* must be last because of priv member */
  struct cfg80211_bss pub;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f05ba8b..a9ed2da 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6602,7 +6602,8 @@ static int nl80211_send_bss(struct sk_buff *msg,
struct netlink_callback *cb,
     nla_put_u32(msg, NL80211_BSS_FREQUENCY, res->channel->center_freq) ||
     nla_put_u32(msg, NL80211_BSS_CHAN_WIDTH, res->scan_width) ||
     nla_put_u32(msg, NL80211_BSS_SEEN_MS_AGO,
- jiffies_to_msecs(jiffies - intbss->ts)))
+ jiffies_to_msecs(jiffies - intbss->ts)) ||
+    nla_put_u64(msg, NL80211_BSS_LAST_SEEN_BOOTTIME, intbss->tfb))
  goto nla_put_failure;

  switch (rdev->wiphy.signal_type) {
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 3a50aa2..275cc92 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -749,10 +749,12 @@ cfg80211_bss_update(struct
cfg80211_registered_device *rdev,
     bool signal_valid)
 {
  struct cfg80211_internal_bss *found = NULL;
+ struct timespec tfb;

  if (WARN_ON(!tmp->pub.channel))
  return NULL;

+ get_monotonic_boottime(&tfb);
  tmp->ts = jiffies;

  spin_lock_bh(&rdev->bss_lock);
@@ -895,6 +897,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
  found = new;
  }

+ found->tfb = (u64)(timespec_to_ns(&tfb) / 1000);
  rdev->bss_generation++;
  bss_ref_get(rdev, found);
  spin_unlock_bh(&rdev->bss_lock);
-- 
2.6.0.rc2.230.g3dd15c0

0001-nl80211-report-age-of-bss-entry-from-boot-in-microse.patch
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