If the driver advertises NL80211_EXT_FEATURE_SCAN_FREQ_KHZ
userspace can omit NL80211_ATTR_SCAN_FREQUENCIES in favor
of an NL80211_ATTR_SCAN_FREQ_KHZ. To get scan results in
KHz userspace must also set the
NL80211_SCAN_FLAG_FREQ_KHZ.
This lets nl80211 remain compatible with older userspaces
while not requring and sending redundant (and potentially
incorrect) scan frequency sets.
Signed-off-by: Thomas Pedersen <thomas@xxxxxxxxxxxx>
---
v3:
- report SCAN_FREQ_KHZ in scan results
- advertise SCAN_FREQ_KHZ support in feature flag
- add SCAN_FLAG_FREQ_KHZ so user can select scan result
frequency units
---
include/uapi/linux/nl80211.h | 13 ++++++++-
net/mac80211/main.c | 2 ++
net/wireless/nl80211.c | 52 +++++++++++++++++++++++++++---------
3 files changed, 54 insertions(+), 13 deletions(-)
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 0ceb4de52d9a..b6012aa5103b 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2492,7 +2492,7 @@ enum nl80211_commands {
* an %NL80211_ATTR_WIPHY_FREQ_OFFSET.
* @NL80211_ATTR_CENTER_FREQ1_OFFSET: Center frequency offset in KHz for the
* first channel segment specified in %NL80211_ATTR_CENTER_FREQ1.
- *
+ * @NL80211_ATTR_SCAN_FREQ_KHZ: nested attribute with KHz frequencies
*
* @NUM_NL80211_ATTR: total number of nl80211_attrs available
* @NL80211_ATTR_MAX: highest attribute number currently defined
@@ -2972,6 +2972,7 @@ enum nl80211_attrs {
NL80211_ATTR_RECEIVE_MULTICAST,
NL80211_ATTR_WIPHY_FREQ_OFFSET,
NL80211_ATTR_CENTER_FREQ1_OFFSET,
+ NL80211_ATTR_SCAN_FREQ_KHZ,
/* add attributes here, update the policy in nl80211.c */
@@ -5721,6 +5722,11 @@ enum nl80211_feature_flags {
* @NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS: management frame registrations
* are possible for multicast frames and those will be reported properly.
*
+ * @NL80211_EXT_FEATURE_SCAN_FREQ_KHZ: This driver supports receiving and
+ * reporting scan request with %NL80211_ATTR_SCAN_FREQ_KHZ. In order to
+ * report %NL80211_ATTR_SCAN_FREQ_KHZ, %NL80211_SCAN_FLAG_FREQ_KHZ must be
+ * included in the scan request.
+ *
* @NUM_NL80211_EXT_FEATURES: number of extended features.
* @MAX_NL80211_EXT_FEATURES: highest extended feature index.
*/
@@ -5774,6 +5780,7 @@ enum nl80211_ext_feature_index {
NL80211_EXT_FEATURE_DEL_IBSS_STA,
NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS,
NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT,
+ NL80211_EXT_FEATURE_SCAN_FREQ_KHZ,
/* add new features before the definition below */
NUM_NL80211_EXT_FEATURES,
@@ -5885,6 +5892,9 @@ enum nl80211_timeout_reason {
* @NL80211_SCAN_FLAG_MIN_PREQ_CONTENT: minimize probe request content to
* only have supported rates and no additional capabilities (unless
* added by userspace explicitly.)
+ * @NL80211_SCAN_FLAG_FREQ_KHZ: report scan results with
+ * %NL80211_ATTR_SCAN_FREQ_KHZ. This also means
+ * %NL80211_ATTR_SCAN_FREQUENCIES will not be included.
*/
enum nl80211_scan_flags {
NL80211_SCAN_FLAG_LOW_PRIORITY = 1<<0,
@@ -5900,6 +5910,7 @@ enum nl80211_scan_flags {
NL80211_SCAN_FLAG_HIGH_ACCURACY = 1<<10,
NL80211_SCAN_FLAG_RANDOM_SN = 1<<11,
NL80211_SCAN_FLAG_MIN_PREQ_CONTENT = 1<<12,
+ NL80211_SCAN_FLAG_FREQ_KHZ = 1<<13,
};
/**
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 06c90d360633..ac74bd780b42 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -596,6 +596,8 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211);
wiphy_ext_feature_set(wiphy,
NL80211_EXT_FEATURE_CONTROL_PORT_NO_PREAUTH);
+ wiphy_ext_feature_set(wiphy,
+ NL80211_EXT_FEATURE_SCAN_FREQ_KHZ);
if (!ops->hw_scan) {
wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN |
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a4ac9b38d0f2..14948cc70587 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -664,6 +664,7 @@ const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
[NL80211_ATTR_PMK_REAUTH_THRESHOLD] = NLA_POLICY_RANGE(NLA_U8, 1, 100),
[NL80211_ATTR_RECEIVE_MULTICAST] = { .type = NLA_FLAG },
[NL80211_ATTR_WIPHY_FREQ_OFFSET] = NLA_POLICY_RANGE(NLA_U32, 0, 999),
+ [NL80211_ATTR_SCAN_FREQ_KHZ] = { .type = NLA_NESTED },
};
/* policy for the key attributes */
@@ -7764,6 +7765,8 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
struct cfg80211_registered_device *rdev = info->user_ptr[0];
struct wireless_dev *wdev = info->user_ptr[1];
struct cfg80211_scan_request *request;
+ struct nlattr *scan_freqs = NULL;
+ bool scan_freqs_khz = false;
struct nlattr *attr;
struct wiphy *wiphy;
int err, tmp, n_ssids = 0, n_channels, i;
@@ -7782,9 +7785,17 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
goto unlock;
}
- if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
- n_channels = validate_scan_freqs(
- info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]);
+ if (info->attrs[NL80211_ATTR_SCAN_FREQ_KHZ]) {
+ if (!wiphy_ext_feature_isset(wiphy,
+ NL80211_EXT_FEATURE_SCAN_FREQ_KHZ))
+ return -EOPNOTSUPP;
+ scan_freqs = info->attrs[NL80211_ATTR_SCAN_FREQ_KHZ];
+ scan_freqs_khz = true;
+ } else if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES])
+ scan_freqs = info->attrs[NL80211_ATTR_SCAN_FREQUENCIES];
+
+ if (scan_freqs) {
+ n_channels = validate_scan_freqs(scan_freqs);
if (!n_channels) {
err = -EINVAL;
goto unlock;
@@ -7832,13 +7843,16 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
}
i = 0;
- if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
+ if (scan_freqs) {
/* user specified, bail out if channel not found */
- nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_FREQUENCIES], tmp) {
+ nla_for_each_nested(attr, scan_freqs, tmp) {
struct ieee80211_channel *chan;
+ int freq = nla_get_u32(attr);
- chan = ieee80211_get_channel(wiphy, nla_get_u32(attr));
+ if (!scan_freqs_khz)
+ freq = MHZ_TO_KHZ(freq);
+ chan = ieee80211_get_channel_khz(wiphy, freq);
if (!chan) {
err = -EINVAL;
goto out_free;
@@ -15273,14 +15287,28 @@ static int nl80211_add_scan_req(struct sk_buff *msg,
}
nla_nest_end(msg, nest);
- nest = nla_nest_start_noflag(msg, NL80211_ATTR_SCAN_FREQUENCIES);
- if (!nest)
- goto nla_put_failure;
- for (i = 0; i < req->n_channels; i++) {
- if (nla_put_u32(msg, i, req->channels[i]->center_freq))
+ if (req->flags & NL80211_SCAN_FLAG_FREQ_KHZ) {
+ nest = nla_nest_start_noflag(msg,
+ NL80211_ATTR_SCAN_FREQ_KHZ);
+ if (!nest)
+ goto nla_put_failure;
+ for (i = 0; i < req->n_channels; i++) {
+ if (nla_put_u32(msg, i,
+ ieee80211_channel_to_khz(req->channels[i])))
+ goto nla_put_failure;
+ }
+ nla_nest_end(msg, nest);
+ } else {
+ nest = nla_nest_start_noflag(msg,
+ NL80211_ATTR_SCAN_FREQUENCIES);
+ if (!nest)
goto nla_put_failure;
+ for (i = 0; i < req->n_channels; i++) {
+ if (nla_put_u32(msg, i, req->channels[i]->center_freq))
+ goto nla_put_failure;
+ }
+ nla_nest_end(msg, nest);
}
- nla_nest_end(msg, nest);
if (req->ie &&
nla_put(msg, NL80211_ATTR_IE, req->ie_len, req->ie))
--
2.20.1
