Introduce filtering for scheduled scans to reduce the number of
unnecessary results (which cause useless wake-ups).
This commit adds a new nested attribute for passing generic filters in
scheduled scan requests. It also adds an implementation for filtering
based on a list of SSIDs. In the future, more types of filters will
be added.
Signed-off-by: Luciano Coelho <coelho@xxxxxx>
---
include/linux/nl80211.h | 33 ++++++++++++++++++++++++++++++++
include/net/cfg80211.h | 8 +++++++
net/wireless/nl80211.c | 48 +++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 87 insertions(+), 2 deletions(-)
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 3769303..7d4edb8 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -769,6 +769,8 @@ enum nl80211_commands {
* that can be added to a scan request
* @NL80211_ATTR_MAX_SCHED_SCAN_IE_LEN: maximum length of information
* elements that can be added to a scheduled scan request
+ * @NL80211_ATTR_MAX_FILTER_SSIDS: number of SSIDs you can use as
+ * filters in a scheduled scan request, a wiphy attribute.
*
* @NL80211_ATTR_SCAN_FREQUENCIES: nested attribute with frequencies (in MHz)
* @NL80211_ATTR_SCAN_SSIDS: nested attribute with SSIDs, leave out for passive
@@ -1011,6 +1013,13 @@ enum nl80211_commands {
* @NL80211_ATTR_SCHED_SCAN_INTERVAL: Interval between scheduled scan
* cycles, in msecs.
+ * @NL80211_ATTR_SCHED_SCAN_FILTER: Nested attribute with various
+ * types of filtering to be used with scheduled scans.
+ * If @NL80211_ATTR_SCAN_SSIDS is passed with values that are not
+ * included in the filter, the driver may return -EINVAL, since
+ * it doesn't make sense to send probe requests with SSIDs that
+ * will be filtered out. This doesn't apply to the wildcard SSID.
+ * If ommited, no filtering is done.
*
* @NL80211_ATTR_INTERFACE_COMBINATIONS: Nested attribute listing the supported
* interface combinations. In each nested item, it contains attributes
@@ -1252,6 +1261,9 @@ enum nl80211_attrs {
NL80211_ATTR_IE_PROBE_RESP,
NL80211_ATTR_IE_ASSOC_RESP,
+ NL80211_ATTR_SCHED_SCAN_FILTER,
+ NL80211_ATTR_MAX_FILTER_SSIDS,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -1711,6 +1723,27 @@ enum nl80211_reg_rule_attr {
};
/**
+ * enum nl80211_sched_scan_filter_attr - scheduled scan filter attributes
+ * @__NL80211_SCHED_SCAN_FILTER_ATTR_INVALID: attribute number 0 is reserved
+ * @NL80211_SCHED_SCAN_FILTER_SSID: A list of SSIDs to be automatically
+ * filtered by the hardware and passed up to the host. SSIDs that are
+ * not present in this list are ignored (without waking up the host).
+ * @NL80211_SCHED_SCAN_FILTER_ATTR_MAX: highest scheduled scan filter
+ * attribute number currently defined
+ * @__NL80211_SCHED_SCAN_FILTER_ATTR_AFTER_LAST: internal use
+ */
+enum nl80211_sched_scan_filter_attr {
+ __NL80211_SCHED_SCAN_FILTER_ATTR_INVALID,
+
+ NL80211_ATTR_SCHED_SCAN_FILTER_SSID,
+
+ /* keep last */
+ __NL80211_SCHED_SCAN_FILTER_ATTR_AFTER_LAST,
+ NL80211_SCHED_SCAN_FILTER_ATTR_MAX =
+ __NL80211_SCHED_SCAN_FILTER_ATTR_AFTER_LAST - 1
+};
+
+/**
* enum nl80211_reg_rule_flags - regulatory rule flags
*
* @NL80211_RRF_NO_OFDM: OFDM modulation not allowed
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index a37f264..a3e58ff 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -882,6 +882,9 @@ struct cfg80211_scan_request {
* @interval: interval between each scheduled scan cycle
* @ie: optional information element(s) to add into Probe Request or %NULL
* @ie_len: length of ie in octets
+ * @filter_ssids: SSIDs to pass to the host (others are filtered out).
+ * If ommited, no filtering is done.
+ * @n_filter_ssids: number of filter SSIDs
* @wiphy: the wiphy this was for
* @dev: the interface
* @channels: channels to scan
@@ -893,6 +896,8 @@ struct cfg80211_sched_scan_request {
u32 interval;
const u8 *ie;
size_t ie_len;
+ struct cfg80211_ssid *filter_ssids;
+ int n_filter_ssids;
/* internal */
struct wiphy *wiphy;
@@ -1806,6 +1811,8 @@ struct wiphy_wowlan_support {
* any given scan
* @max_sched_scan_ssids: maximum number of SSIDs the device can scan
* for in any given scheduled scan
+ * @max_filter_ssids: maximum number of SSIDs the device can filter when
+ * performing a scheduled scan, 0 if filtering is not supported
* @max_scan_ie_len: maximum length of user-controlled IEs device can
* add to probe request frames transmitted during a scan, must not
* include fixed IEs like supported rates
@@ -1863,6 +1870,7 @@ struct wiphy {
int bss_priv_size;
u8 max_scan_ssids;
u8 max_sched_scan_ssids;
+ u8 max_filter_ssids;
u16 max_scan_ie_len;
u16 max_sched_scan_ie_len;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 57ecfa4..cd46a07 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -189,6 +189,7 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
.len = IEEE80211_MAX_DATA_LEN },
[NL80211_ATTR_IE_ASSOC_RESP] = { .type = NLA_BINARY,
.len = IEEE80211_MAX_DATA_LEN },
+ [NL80211_ATTR_SCHED_SCAN_FILTER] = { .type = NLA_NESTED },
};
/* policy for the key attributes */
@@ -714,6 +715,8 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
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_FILTER_SSIDS,
+ dev->wiphy.max_filter_ssids);
if (dev->wiphy.flags & WIPHY_FLAG_IBSS_RSN)
NLA_PUT_FLAG(msg, NL80211_ATTR_SUPPORT_IBSS_RSN);
@@ -3596,9 +3599,9 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
struct cfg80211_sched_scan_request *request;
struct cfg80211_registered_device *rdev = info->user_ptr[0];
struct net_device *dev = info->user_ptr[1];
- struct nlattr *attr;
+ struct nlattr *attr, *attr2;
struct wiphy *wiphy;
- int err, tmp, n_ssids = 0, n_channels, i;
+ int err, tmp, n_ssids = 0, n_filter_ssids = 0, n_channels, i;
u32 interval;
enum ieee80211_band band;
size_t ie_len;
@@ -3640,6 +3643,17 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
if (n_ssids > wiphy->max_sched_scan_ssids)
return -EINVAL;
+ if (info->attrs[NL80211_ATTR_SCHED_SCAN_FILTER]) {
+ attr = nla_find_nested(info->attrs[NL80211_ATTR_SCHED_SCAN_FILTER],
+ NL80211_ATTR_SCHED_SCAN_FILTER_SSID);
+ if (attr)
+ nla_for_each_nested(attr2, attr, tmp)
+ n_filter_ssids++;
+ }
+
+ if (n_filter_ssids > wiphy->max_filter_ssids)
+ return -EINVAL;
+
if (info->attrs[NL80211_ATTR_IE])
ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
else
@@ -3657,6 +3671,7 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
request = kzalloc(sizeof(*request)
+ sizeof(*request->ssids) * n_ssids
+ + sizeof(*request->filter_ssids) * n_filter_ssids
+ sizeof(*request->channels) * n_channels
+ ie_len, GFP_KERNEL);
if (!request) {
@@ -3674,6 +3689,17 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
request->ie = (void *)(request->channels + n_channels);
}
+ if (n_filter_ssids) {
+ if (request->ie)
+ request->filter_ssids = (void *)(request->ie + ie_len);
+ else if (request->ssids)
+ request->filter_ssids =
+ (void *)(request->ssids + n_ssids);
+ else
+ request->filter_ssids =
+ (void *)(request->channels + n_channels);
+ }
+
i = 0;
if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
/* user specified, bail out if channel not found */
@@ -3738,6 +3764,24 @@ static int nl80211_start_sched_scan(struct sk_buff *skb,
}
}
+ i = 0;
+ if (info->attrs[NL80211_ATTR_SCHED_SCAN_FILTER]) {
+ struct nlattr *attr2;
+ attr = nla_find_nested(info->attrs[NL80211_ATTR_SCHED_SCAN_FILTER],
+ NL80211_ATTR_SCHED_SCAN_FILTER_SSID);
+ if (attr)
+ nla_for_each_nested(attr2, attr, tmp) {
+ if (nla_len(attr2) > IEEE80211_MAX_SSID_LEN) {
+ err = -EINVAL;
+ goto out_free;
+ }
+ memcpy(request->filter_ssids[i].ssid, nla_data(attr2),
+ nla_len(attr2));
+ request->filter_ssids[i].ssid_len = nla_len(attr2);
+ i++;
+ }
+ }
+
if (info->attrs[NL80211_ATTR_IE]) {
request->ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
memcpy((void *)request->ie,
--
1.7.1
--
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