Add support to parse NL80211_ATTR_CHANNEL_WIDTH attribute
and convert it from enum nl80211_chan_width semantics to
enum nl80211_bss_scan_width semantics for nl80211_commands
NL80211_CMD_TRIGGER_SCAN and NL80211_CMD_START_SCHED_SCAN.
Also add a new scan_width_set flag in the scan request sent
to the driver to indicate whether the scan channel width is
passed from the userspace.
If channel width lower than 20 MHz is specified, it will be
converted from enum nl80211_chan_width value to the
corresponding enum nl80211_bss_scan_width value and it is
expected that only BSSs using this channel width can be
found. If 20 MHz or higher channel width is specified, it
is expected that all the BSSs using 20 MHz or higher channel
width can be found as their management frames can be
received on the primary 20 MHz channel. If this attribute is
not passed from the userspace, the scan channel width will
be decided by the driver.
One example for such use case is connection between drone
and drone controller, userspace may need to specify the
scan channel width, which needs to be passed to the driver
to trigger the scan on this specified channel width.
Signed-off-by: Xinyue Ling <quic_xinyling@xxxxxxxxxxx>
---
include/net/cfg80211.h | 6 +++++
include/uapi/linux/nl80211.h | 19 ++++++++++++++-
net/wireless/nl80211.c | 47 +++++++++++++++++++++++++++++++++++-
3 files changed, 70 insertions(+), 2 deletions(-)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 54a77d906b2d..bbf566190a87 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2400,6 +2400,8 @@ struct cfg80211_scan_6ghz_params {
* @channels: channels to scan on.
* @n_channels: total number of channels to scan
* @scan_width: channel width for scanning
+ * @scan_width_set: channel width for scanning is specified from the
+ * userspace
* @ie: optional information element(s) to add into Probe Request or %NULL
* @ie_len: length of ie in octets
* @duration: how long to listen on each channel, in TUs. If
@@ -2430,6 +2432,7 @@ struct cfg80211_scan_request {
int n_ssids;
u32 n_channels;
enum nl80211_bss_scan_width scan_width;
+ bool scan_width_set;
const u8 *ie;
size_t ie_len;
u16 duration;
@@ -2525,6 +2528,8 @@ struct cfg80211_bss_select_adjust {
* @n_ssids: number of SSIDs
* @n_channels: total number of channels to scan
* @scan_width: channel width for scanning
+ * @scan_width_set: channel width for scanning is specified from the
+ * userspace
* @ie: optional information element(s) to add into Probe Request or %NULL
* @ie_len: length of ie in octets
* @flags: bit field of flags controlling operation
@@ -2573,6 +2578,7 @@ struct cfg80211_sched_scan_request {
int n_ssids;
u32 n_channels;
enum nl80211_bss_scan_width scan_width;
+ bool scan_width_set;
const u8 *ie;
size_t ie_len;
u32 flags;
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 3f15ac05f581..03b60d987a1b 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -501,7 +501,13 @@
* %NL80211_ATTR_TX_NO_CCK_RATE is used to decide whether to send the
* probe requests at CCK rate or not. %NL80211_ATTR_BSSID can be used to
* specify a BSSID to scan for; if not included, the wildcard BSSID will
- * be used.
+ * be used. %NL80211_ATTR_CHANNEL_WIDTH can be passed from the userspace
+ * to specify the scan channel bandwidth; if channel bandwidth lower than
+ * 20 MHz is specified, it is expected that only BSSs using this channel
+ * bandwidth can be found; if 20 MHz or higher channel bandwidth is
+ * specified, it is expected that all the BSSs using 20 MHz or higher
+ * channel bandwidth can be found; if not included, the scan channel
+ * bandwidth will be decided by the driver.
* @NL80211_CMD_NEW_SCAN_RESULTS: scan notification (as a reply to
* NL80211_CMD_GET_SCAN and on the "scan" multicast group)
* @NL80211_CMD_SCAN_ABORTED: scan was aborted, for unspecified reasons,
@@ -530,6 +536,13 @@
* is supplied. If the device supports multiple concurrent scheduled
* scans, it will allow such when the caller provides the flag attribute
* %NL80211_ATTR_SCHED_SCAN_MULTI to indicate user-space support for it.
+ * %NL80211_ATTR_CHANNEL_WIDTH can be passed from the userspace to specify
+ * the scan channel width; if channel bandwidth lower than 20 MHz is
+ * specified, it is expected that only BSSs using this channel bandwidth
+ * can be found; if 20 MHz or higher channel bandwidth is specified, it is
+ * expected that all the BSSs using 20 MHz or higher channel bandwidth can
+ * be found; if not included, the scan channel bandwidth will be decided by
+ * the driver.
* @NL80211_CMD_STOP_SCHED_SCAN: stop a scheduled scan. Returns -ENOENT if
* scheduled scan is not running. The caller may assume that as soon
* as the call returns, it is safe to start a new scheduled scan again.
@@ -4875,6 +4888,8 @@ enum nl80211_key_mode {
* @NL80211_CHAN_WIDTH_16: 16 MHz OFDM channel
* @NL80211_CHAN_WIDTH_320: 320 MHz channel, the %NL80211_ATTR_CENTER_FREQ1
* attribute must be provided as well
+ * @NUM_NL80211_CHAN_WIDTH: number of values, avoid using this in userspace
+ * since newer kernel versions may support more channel widths
*/
enum nl80211_chan_width {
NL80211_CHAN_WIDTH_20_NOHT,
@@ -4891,6 +4906,8 @@ enum nl80211_chan_width {
NL80211_CHAN_WIDTH_8,
NL80211_CHAN_WIDTH_16,
NL80211_CHAN_WIDTH_320,
+
+ NUM_NL80211_CHAN_WIDTH
};
/**
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 64cf6110ce9d..2048a98c3273 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -478,7 +478,8 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
NL80211_EDMG_BW_CONFIG_MIN,
NL80211_EDMG_BW_CONFIG_MAX),
- [NL80211_ATTR_CHANNEL_WIDTH] = { .type = NLA_U32 },
+ [NL80211_ATTR_CHANNEL_WIDTH] =
+ NLA_POLICY_MAX(NLA_U32, NUM_NL80211_CHAN_WIDTH),
[NL80211_ATTR_CENTER_FREQ1] = { .type = NLA_U32 },
[NL80211_ATTR_CENTER_FREQ1_OFFSET] = NLA_POLICY_RANGE(NLA_U32, 0, 999),
[NL80211_ATTR_CENTER_FREQ2] = { .type = NLA_U32 },
@@ -8924,6 +8925,34 @@ nl80211_check_scan_flags(struct wiphy *wiphy, struct wireless_dev *wdev,
return 0;
}
+static enum nl80211_bss_scan_width
+chan_width_to_scan_width(enum nl80211_chan_width width)
+{
+ switch (width) {
+ case NL80211_CHAN_WIDTH_5:
+ return NL80211_BSS_CHAN_WIDTH_5;
+ case NL80211_CHAN_WIDTH_10:
+ return NL80211_BSS_CHAN_WIDTH_10;
+ case NL80211_CHAN_WIDTH_1:
+ return NL80211_BSS_CHAN_WIDTH_1;
+ case NL80211_CHAN_WIDTH_2:
+ return NL80211_BSS_CHAN_WIDTH_2;
+ case NL80211_CHAN_WIDTH_4:
+ return NL80211_BSS_CHAN_WIDTH_4;
+ case NL80211_CHAN_WIDTH_8:
+ return NL80211_BSS_CHAN_WIDTH_8;
+ case NL80211_CHAN_WIDTH_16:
+ return NL80211_BSS_CHAN_WIDTH_16;
+ default:
+ /* for the rest of channel bandwidth values (20 MHz or higher),
+ * scan channel bandwidth can be set to NL80211_BSS_CHAN_WIDTH_20
+ * as management frames of BSSs using 20 MHz or higher channel
+ * can be received on the primary 20 MHz channel
+ */
+ return NL80211_BSS_CHAN_WIDTH_20;
+ }
+}
+
static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
{
struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -9120,6 +9149,14 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
nla_get_flag(info->attrs[NL80211_ATTR_MEASUREMENT_DURATION_MANDATORY]);
}
+ if (info->attrs[NL80211_ATTR_CHANNEL_WIDTH]) {
+ enum nl80211_chan_width chan_width;
+
+ chan_width = nla_get_u32(info->attrs[NL80211_ATTR_CHANNEL_WIDTH]);
+ request->scan_width = chan_width_to_scan_width(chan_width);
+ request->scan_width_set = true;
+ }
+
err = nl80211_check_scan_flags(wiphy, wdev, request, info->attrs,
false);
if (err)
@@ -9611,6 +9648,14 @@ nl80211_parse_sched_scan(struct wiphy *wiphy, struct wireless_dev *wdev,
request->ie_len);
}
+ if (attrs[NL80211_ATTR_CHANNEL_WIDTH]) {
+ enum nl80211_chan_width chan_width;
+
+ chan_width = nla_get_u32(attrs[NL80211_ATTR_CHANNEL_WIDTH]);
+ request->scan_width = chan_width_to_scan_width(chan_width);
+ request->scan_width_set = true;
+ }
+
err = nl80211_check_scan_flags(wiphy, wdev, request, attrs, true);
if (err)
goto out_free;
--
2.25.1
