2012-06-21 18:10:06

by Thomas Pedersen

Subject: [PATCH v4] nl80211: specify RSSI threshold in scheduled scan

Support configuring an RSSI threshold in dBm (s32) when requesting
scheduled scan, below which a BSS won't be reported by the cfg80211
driver.

Signed-off-by: Thomas Pedersen <[email protected]>
---
v2:
naming (Kalle)
remove WIPHY_FLAG (Kalle)
use sched_scan_match_attr (Luca)

v3:
nl80211 API names (Holger)
misc. / typos (Johannes)

v4:
Turn off filter by default with really low RSSI value (Johannes)

include/linux/nl80211.h | 6 ++++++
include/net/cfg80211.h | 2 ++
net/wireless/nl80211.c | 9 ++++++++-
3 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 970afdf..4f07c00 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1524,6 +1524,9 @@ enum nl80211_attrs {

#define NL80211_MIN_REMAIN_ON_CHANNEL_TIME 10

+/* default RSSI threshold for scan results if none specified. */
+#define NL80211_SCAN_RSSI_THOLD_OFF -300
+
/**
* enum nl80211_iftype - (virtual) interface types
*
@@ -1956,6 +1959,8 @@ enum nl80211_reg_rule_attr {
* @__NL80211_SCHED_SCAN_MATCH_ATTR_INVALID: attribute number 0 is reserved
* @NL80211_SCHED_SCAN_MATCH_ATTR_SSID: SSID to be used for matching,
* only report BSS with matching SSID.
+ * @NL80211_SCHED_SCAN_MATCH_ATTR_RSSI: RSSI threshold (in dBm) for reporting a
+ * BSS in scan results. Filtering is turned off if not specified.
* @NL80211_SCHED_SCAN_MATCH_ATTR_MAX: highest scheduled scan filter
* attribute number currently defined
* @__NL80211_SCHED_SCAN_MATCH_ATTR_AFTER_LAST: internal use
@@ -1964,6 +1969,7 @@ enum nl80211_sched_scan_match_attr {
__NL80211_SCHED_SCAN_MATCH_ATTR_INVALID,

NL80211_ATTR_SCHED_SCAN_MATCH_SSID,
+ NL80211_SCHED_SCAN_MATCH_ATTR_RSSI,

/* keep last */
__NL80211_SCHED_SCAN_MATCH_ATTR_AFTER_LAST,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 7319f25..55a9d24 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -975,6 +975,7 @@ struct cfg80211_match_set {
* @wiphy: the wiphy this was for
* @dev: the interface
* @channels: channels to scan
+ * @rssi_thold: don't report scan results below this threshold (in s32 dBm)
*/
struct cfg80211_sched_scan_request {
struct cfg80211_ssid *ssids;
@@ -985,6 +986,7 @@ struct cfg80211_sched_scan_request {
size_t ie_len;
struct cfg80211_match_set *match_sets;
int n_match_sets;
+ s32 rssi_thold;

/* internal */
struct wiphy *wiphy;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7ae54b8..284758b 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -252,6 +252,7 @@ static const struct nla_policy
nl80211_match_policy[NL80211_SCHED_SCAN_MATCH_ATTR_MAX + 1] = {
[NL80211_ATTR_SCHED_SCAN_MATCH_SSID] = { .type = NLA_BINARY,
.len = IEEE80211_MAX_SSID_LEN },
+ [NL80211_SCHED_SCAN_MATCH_ATTR_RSSI] = { .type = NLA_U32 },
};

/* ifidx get helper */
@@ -4241,7 +4242,7 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
nla_for_each_nested(attr,
info->attrs[NL80211_ATTR_SCHED_SCAN_MATCH],
tmp) {
- struct nlattr *ssid;
+ struct nlattr *ssid, *rssi;

nla_parse(tb, NL80211_SCHED_SCAN_MATCH_ATTR_MAX,
nla_data(attr), nla_len(attr),
@@ -4257,6 +4258,12 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
request->match_sets[i].ssid.ssid_len =
nla_len(ssid);
}
+ rssi = tb[NL80211_SCHED_SCAN_MATCH_ATTR_RSSI];
+ if (rssi)
+ request->rssi_thold = nla_get_u32(rssi);
+ else
+ request->rssi_thold =
+ NL80211_SCAN_RSSI_THOLD_OFF;
i++;
}
}
--
1.7.4.1

2012-06-26 07:33:32

by Johannes Berg

Subject: Re: [PATCH v4] nl80211: specify RSSI threshold in scheduled scan

On Thu, 2012-06-21 at 11:09 -0700, Thomas Pedersen wrote:
> Support configuring an RSSI threshold in dBm (s32) when requesting
> scheduled scan, below which a BSS won't be reported by the cfg80211
> driver.

Applied, thanks.

johannes