nl80211/cfg80211: add match filtering for sched_scan
Introduce filtering for scheduled scans to reduce the number of
unnecessary results (which cause useless wake-ups).
Add a new nested attribute where sets of parameters to be matched can
be passed when starting a scheduled scan. Only scan results that
match any of the sets will be returned.
At this point, the set consists of a single parameter, an SSID. This
can be easily extended in the future to support more complex matches.
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0cda46a..f4cfd3a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -190,6 +190,7 @@
[NL80211_ATTR_IE_ASSOC_RESP] = { .type = NLA_BINARY,
.len = IEEE80211_MAX_DATA_LEN },
[NL80211_ATTR_ROAM_SUPPORT] = { .type = NLA_FLAG },
+ [NL80211_ATTR_SCHED_SCAN_MATCH] = { .type = NLA_NESTED },
};
/* policy for the key attributes */
@@ -232,6 +233,12 @@
[NL80211_REKEY_DATA_REPLAY_CTR] = { .len = NL80211_REPLAY_CTR_LEN },
};
+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 },
+};
+
/* ifidx get helper */
static int nl80211_get_ifidx(struct netlink_callback *cb)
{
@@ -715,6 +722,8 @@
dev->wiphy.max_scan_ie_len);
NLA_PUT_U16(msg, NL80211_ATTR_MAX_SCHED_SCAN_IE_LEN,
dev->wiphy.max_sched_scan_ie_len);
+ NLA_PUT_U8(msg, NL80211_ATTR_MAX_MATCH_SETS,
+ dev->wiphy.max_match_sets);
if (dev->wiphy.flags & WIPHY_FLAG_IBSS_RSN)
NLA_PUT_FLAG(msg, NL80211_ATTR_SUPPORT_IBSS_RSN);
@@ -3632,10 +3641,11 @@
struct net_device *dev = info->user_ptr[1];
struct nlattr *attr;
struct wiphy *wiphy;
- int err, tmp, n_ssids = 0, n_channels, i;
+ int err, tmp, n_ssids = 0, n_match_sets = 0, n_channels, i;
u32 interval;
enum ieee80211_band band;
size_t ie_len;
+ struct nlattr *tb[NL80211_SCHED_SCAN_MATCH_ATTR_MAX + 1];
if (!(rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN) ||
!rdev->ops->sched_scan_start)
@@ -3674,6 +3684,15 @@
if (n_ssids > wiphy->max_sched_scan_ssids)
return -EINVAL;
+ if (info->attrs[NL80211_ATTR_SCHED_SCAN_MATCH])
+ nla_for_each_nested(attr,
+ info->attrs[NL80211_ATTR_SCHED_SCAN_MATCH],
+ tmp)
+ n_match_sets++;
+
+ if (n_match_sets > wiphy->max_match_sets)
+ return -EINVAL;
+
if (info->attrs[NL80211_ATTR_IE])
ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
else
@@ -3691,6 +3710,7 @@
request = kzalloc(sizeof(*request)
+ sizeof(*request->ssids) * n_ssids
+ + sizeof(*request->match_sets) * n_match_sets
+ sizeof(*request->channels) * n_channels
+ ie_len, GFP_KERNEL);
if (!request) {
@@ -3708,6 +3728,18 @@
request->ie = (void *)(request->channels + n_channels);
}
+ if (n_match_sets) {
+ if (request->ie)
+ request->match_sets = (void *)(request->ie + ie_len);
+ else if (request->ssids)
+ request->match_sets =
+ (void *)(request->ssids + n_ssids);
+ else
+ request->match_sets =
+ (void *)(request->channels + n_channels);
+ }
+ request->n_match_sets = n_match_sets;
+
i = 0;
if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
/* user specified, bail out if channel not found */
@@ -3772,6 +3804,31 @@
}
}
+ i = 0;
+ if (info->attrs[NL80211_ATTR_SCHED_SCAN_MATCH]) {
+ nla_for_each_nested(attr,
+ info->attrs[NL80211_ATTR_SCHED_SCAN_MATCH],
+ tmp) {
+ struct nlattr *ssid;
+
+ nla_parse(tb, NL80211_SCHED_SCAN_MATCH_ATTR_MAX,
+ nla_data(attr), nla_len(attr),
+ nl80211_match_policy);
+ ssid = tb[NL80211_ATTR_SCHED_SCAN_MATCH_SSID];
+ if (ssid) {
+ if (nla_len(ssid) > IEEE80211_MAX_SSID_LEN) {
+ err = -EINVAL;
+ goto out_free;
+ }
+ memcpy(request->match_sets[i].ssid.ssid,
+ nla_data(ssid), nla_len(ssid));
+ request->match_sets[i].ssid.ssid_len =
+ nla_len(ssid);
+ }
+ i++;
+ }
+ }
+
if (info->attrs[NL80211_ATTR_IE]) {
request->ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
memcpy((void *)request->ie,
