nl80211: add KHz frequency offset for most wifi commands

cfg80211 recently gained the ability to understand a
frequency offset component in KHz. Expose this in nl80211
through the new attributes NL80211_ATTR_WIPHY_FREQ_OFFSET,
NL80211_FREQUENCY_ATTR_OFFSET,
NL80211_ATTR_CENTER_FREQ1_OFFSET, and
NL80211_BSS_FREQUENCY_OFFSET.

These add support to send and receive a KHz offset
component with the following NL80211 commands:

- NL80211_CMD_FRAME
- NL80211_CMD_GET_SCAN
- NL80211_CMD_AUTHENTICATE
- NL80211_CMD_ASSOCIATE
- NL80211_CMD_CONNECT

Along with any other command which takes a chandef, ie:

- NL80211_CMD_SET_CHANNEL
- NL80211_CMD_SET_WIPHY
- NL80211_CMD_START_AP
- NL80211_CMD_RADAR_DETECT
- NL80211_CMD_NOTIFY_RADAR
- NL80211_CMD_CHANNEL_SWITCH
- NL80211_JOIN_IBSS
- NL80211_CMD_REMAIN_ON_CHANNEL
- NL80211_CMD_JOIN_OCB
- NL80211_CMD_JOIN_MESH
- NL80211_CMD_TDLS_CHANNEL_SWITCH

If the driver advertises a band containing channels with
frequency offset, it must also verify support for
frequency offset channels in its cfg80211 ops, or return
an error.
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200430172554.18383-3-thomas@adapt-ip.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -296,13 +296,14 @@
  *	to get a list of all present wiphys.
  * @NL80211_CMD_SET_WIPHY: set wiphy parameters, needs %NL80211_ATTR_WIPHY or
  *	%NL80211_ATTR_IFINDEX; can be used to set %NL80211_ATTR_WIPHY_NAME,
- *	%NL80211_ATTR_WIPHY_TXQ_PARAMS, %NL80211_ATTR_WIPHY_FREQ (and the
- *	attributes determining the channel width; this is used for setting
- *	monitor mode channel),  %NL80211_ATTR_WIPHY_RETRY_SHORT,
- *	%NL80211_ATTR_WIPHY_RETRY_LONG, %NL80211_ATTR_WIPHY_FRAG_THRESHOLD,
- *	and/or %NL80211_ATTR_WIPHY_RTS_THRESHOLD.
- *	However, for setting the channel, see %NL80211_CMD_SET_CHANNEL
- *	instead, the support here is for backward compatibility only.
+ *	%NL80211_ATTR_WIPHY_TXQ_PARAMS, %NL80211_ATTR_WIPHY_FREQ,
+ *	%NL80211_ATTR_WIPHY_FREQ_OFFSET (and the attributes determining the
+ *	channel width; this is used for setting monitor mode channel),
+ *	%NL80211_ATTR_WIPHY_RETRY_SHORT, %NL80211_ATTR_WIPHY_RETRY_LONG,
+ *	%NL80211_ATTR_WIPHY_FRAG_THRESHOLD, and/or
+ *	%NL80211_ATTR_WIPHY_RTS_THRESHOLD.  However, for setting the channel,
+ *	see %NL80211_CMD_SET_CHANNEL instead, the support here is for backward
+ *	compatibility only.
  * @NL80211_CMD_NEW_WIPHY: Newly created wiphy, response to get request
  *	or rename notification. Has attributes %NL80211_ATTR_WIPHY and
  *	%NL80211_ATTR_WIPHY_NAME.
@@ -351,7 +352,8 @@
  *	%NL80211_ATTR_AUTH_TYPE, %NL80211_ATTR_INACTIVITY_TIMEOUT,
  *	%NL80211_ATTR_ACL_POLICY and %NL80211_ATTR_MAC_ADDRS.
  *	The channel to use can be set on the interface or be given using the
- *	%NL80211_ATTR_WIPHY_FREQ and the attributes determining channel width.
+ *	%NL80211_ATTR_WIPHY_FREQ and %NL80211_ATTR_WIPHY_FREQ_OFFSET, and the
+ *	attributes determining channel width.
  * @NL80211_CMD_NEW_BEACON: old alias for %NL80211_CMD_START_AP
  * @NL80211_CMD_STOP_AP: Stop AP operation on the given interface
  * @NL80211_CMD_DEL_BEACON: old alias for %NL80211_CMD_STOP_AP
@@ -536,11 +538,12 @@
  *	interface. %NL80211_ATTR_MAC is used to specify PeerSTAAddress (and
  *	BSSID in case of station mode). %NL80211_ATTR_SSID is used to specify
  *	the SSID (mainly for association, but is included in authentication
- *	request, too, to help BSS selection. %NL80211_ATTR_WIPHY_FREQ is used
- *	to specify the frequence of the channel in MHz. %NL80211_ATTR_AUTH_TYPE
- *	is used to specify the authentication type. %NL80211_ATTR_IE is used to
- *	define IEs (VendorSpecificInfo, but also including RSN IE and FT IEs)
- *	to be added to the frame.
+ *	request, too, to help BSS selection. %NL80211_ATTR_WIPHY_FREQ +
+ *	%NL80211_ATTR_WIPHY_FREQ_OFFSET is used to specify the frequence of the
+ *	channel in MHz. %NL80211_ATTR_AUTH_TYPE is used to specify the
+ *	authentication type. %NL80211_ATTR_IE is used to define IEs
+ *	(VendorSpecificInfo, but also including RSN IE and FT IEs) to be added
+ *	to the frame.
  *	When used as an event, this reports reception of an Authentication
  *	frame in station and IBSS modes when the local MLME processed the
  *	frame, i.e., it was for the local STA and was received in correct
@@ -595,8 +598,9 @@
  *	requests to connect to a specified network but without separating
  *	auth and assoc steps. For this, you need to specify the SSID in a
  *	%NL80211_ATTR_SSID attribute, and can optionally specify the association
- *	IEs in %NL80211_ATTR_IE, %NL80211_ATTR_AUTH_TYPE, %NL80211_ATTR_USE_MFP,
- *	%NL80211_ATTR_MAC, %NL80211_ATTR_WIPHY_FREQ, %NL80211_ATTR_CONTROL_PORT,
+ *	IEs in %NL80211_ATTR_IE, %NL80211_ATTR_AUTH_TYPE,
+ *	%NL80211_ATTR_USE_MFP, %NL80211_ATTR_MAC, %NL80211_ATTR_WIPHY_FREQ,
+ *	%NL80211_ATTR_WIPHY_FREQ_OFFSET, %NL80211_ATTR_CONTROL_PORT,
  *	%NL80211_ATTR_CONTROL_PORT_ETHERTYPE,
  *	%NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT,
  *	%NL80211_ATTR_CONTROL_PORT_OVER_NL80211, %NL80211_ATTR_MAC_HINT, and
@@ -1433,7 +1437,8 @@ enum nl80211_commands {
  *	of &enum nl80211_chan_width, describing the channel width. See the
  *	documentation of the enum for more information.
  * @NL80211_ATTR_CENTER_FREQ1: Center frequency of the first part of the
- *	channel, used for anything but 20 MHz bandwidth
+ *	channel, used for anything but 20 MHz bandwidth. In S1G this is the
+ *	operating channel center frequency.
  * @NL80211_ATTR_CENTER_FREQ2: Center frequency of the second part of the
  *	channel, used only for 80+80 MHz bandwidth
  * @NL80211_ATTR_WIPHY_CHANNEL_TYPE: included with NL80211_ATTR_WIPHY_FREQ
@@ -2480,9 +2485,14 @@ enum nl80211_commands {
  *	entry without having to force a disconnection after the PMK timeout. If
  *	no roaming occurs between the reauth threshold and PMK expiration,
  *	disassociation is still forced.
- *
  * @NL80211_ATTR_RECEIVE_MULTICAST: multicast flag for the
  *	%NL80211_CMD_REGISTER_FRAME command, see the description there.
+ * @NL80211_ATTR_WIPHY_FREQ_OFFSET: offset of the associated
+ *	%NL80211_ATTR_WIPHY_FREQ in positive KHz. Only valid when supplied with
+ *	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.
+ *
  *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
@@ -2960,6 +2970,8 @@ enum nl80211_attrs {
 	NL80211_ATTR_PMK_REAUTH_THRESHOLD,
 
 	NL80211_ATTR_RECEIVE_MULTICAST,
+	NL80211_ATTR_WIPHY_FREQ_OFFSET,
+	NL80211_ATTR_CENTER_FREQ1_OFFSET,
 
 	/* add attributes here, update the policy in nl80211.c */
 
@@ -3682,6 +3694,7 @@ enum nl80211_wmm_rule {
  *	(see &enum nl80211_wmm_rule)
  * @NL80211_FREQUENCY_ATTR_NO_HE: HE operation is not allowed on this channel
  *	in current regulatory domain.
+ * @NL80211_FREQUENCY_ATTR_OFFSET: frequency offset in KHz
  * @NL80211_FREQUENCY_ATTR_MAX: highest frequency attribute number
  *	currently defined
  * @__NL80211_FREQUENCY_ATTR_AFTER_LAST: internal use
@@ -3712,6 +3725,7 @@ enum nl80211_frequency_attr {
 	NL80211_FREQUENCY_ATTR_NO_10MHZ,
 	NL80211_FREQUENCY_ATTR_WMM,
 	NL80211_FREQUENCY_ATTR_NO_HE,
+	NL80211_FREQUENCY_ATTR_OFFSET,
 
 	/* keep last */
 	__NL80211_FREQUENCY_ATTR_AFTER_LAST,
@@ -4482,6 +4496,7 @@ enum nl80211_bss_scan_width {
  * @NL80211_BSS_CHAIN_SIGNAL: per-chain signal strength of last BSS update.
  *	Contains a nested array of signal strength attributes (u8, dBm),
  *	using the nesting index as the antenna number.
+ * @NL80211_BSS_FREQUENCY_OFFSET: frequency offset in KHz
  * @__NL80211_BSS_AFTER_LAST: internal
  * @NL80211_BSS_MAX: highest BSS attribute
  */
@@ -4506,6 +4521,7 @@ enum nl80211_bss {
 	NL80211_BSS_PARENT_TSF,
 	NL80211_BSS_PARENT_BSSID,
 	NL80211_BSS_CHAIN_SIGNAL,
+	NL80211_BSS_FREQUENCY_OFFSET,
 
 	/* keep last */
 	__NL80211_BSS_AFTER_LAST,

net/wireless/nl80211.c

@@ -365,6 +365,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 
 	[NL80211_ATTR_CHANNEL_WIDTH] = { .type = NLA_U32 },
 	[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 },
 
 	[NL80211_ATTR_WIPHY_RETRY_SHORT] = NLA_POLICY_MIN(NLA_U8, 1),
@@ -638,6 +639,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_PMK_LIFETIME] = NLA_POLICY_MIN(NLA_U32, 1),
 	[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),
 };
 
 /* policy for the key attributes */
@@ -904,6 +906,9 @@ static int nl80211_msg_put_channel(struct sk_buff *msg, struct wiphy *wiphy,
 			chan->center_freq))
 		goto nla_put_failure;
 
+	if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_OFFSET, chan->freq_offset))
+		goto nla_put_failure;
+
 	if ((chan->flags & IEEE80211_CHAN_DISABLED) &&
 	    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_DISABLED))
 		goto nla_put_failure;
@@ -1309,13 +1314,11 @@ static int nl80211_key_allowed(struct wireless_dev *wdev)
 }
 
 static struct ieee80211_channel *nl80211_get_valid_chan(struct wiphy *wiphy,
-							struct nlattr *tb)
+							u32 freq)
 {
 	struct ieee80211_channel *chan;
 
-	if (tb == NULL)
-		return NULL;
-	chan = ieee80211_get_channel(wiphy, nla_get_u32(tb));
+	chan = ieee80211_get_channel_khz(wiphy, freq);
 	if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
 		return NULL;
 	return chan;
@@ -2770,13 +2773,17 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
 	if (!attrs[NL80211_ATTR_WIPHY_FREQ])
 		return -EINVAL;
 
-	control_freq = nla_get_u32(attrs[NL80211_ATTR_WIPHY_FREQ]);
+	control_freq = MHZ_TO_KHZ(
+			nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+	if (info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET])
+		control_freq +=
+		    nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET]);
 
 	memset(chandef, 0, sizeof(*chandef));
-
-	chandef->chan = ieee80211_get_channel(&rdev->wiphy, control_freq);
+	chandef->chan = ieee80211_get_channel_khz(&rdev->wiphy, control_freq);
 	chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
-	chandef->center_freq1 = control_freq;
+	chandef->center_freq1 = KHZ_TO_MHZ(control_freq);
+	chandef->freq1_offset = control_freq % 1000;
 	chandef->center_freq2 = 0;
 
 	/* Primary channel not allowed */
@@ -2824,9 +2831,15 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
 	} else if (attrs[NL80211_ATTR_CHANNEL_WIDTH]) {
 		chandef->width =
 			nla_get_u32(attrs[NL80211_ATTR_CHANNEL_WIDTH]);
-		if (attrs[NL80211_ATTR_CENTER_FREQ1])
+		if (attrs[NL80211_ATTR_CENTER_FREQ1]) {
 			chandef->center_freq1 =
 				nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ1]);
+			if (attrs[NL80211_ATTR_CENTER_FREQ1_OFFSET])
+				chandef->freq1_offset = nla_get_u32(
+				      attrs[NL80211_ATTR_CENTER_FREQ1_OFFSET]);
+			else
+				chandef->freq1_offset = 0;
+		}
 		if (attrs[NL80211_ATTR_CENTER_FREQ2])
 			chandef->center_freq2 =
 				nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ2]);
@@ -3259,6 +3272,9 @@ static int nl80211_send_chandef(struct sk_buff *msg,
 	if (nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ,
 			chandef->chan->center_freq))
 		return -ENOBUFS;
+	if (nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ_OFFSET,
+			chandef->chan->freq_offset))
+		return -ENOBUFS;
 	switch (chandef->width) {
 	case NL80211_CHAN_WIDTH_20_NOHT:
 	case NL80211_CHAN_WIDTH_20:
@@ -8873,6 +8889,8 @@ static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb,
 		goto nla_put_failure;
 	if (nla_put_u16(msg, NL80211_BSS_CAPABILITY, res->capability) ||
 	    nla_put_u32(msg, NL80211_BSS_FREQUENCY, res->channel->center_freq) ||
+	    nla_put_u32(msg, NL80211_BSS_FREQUENCY_OFFSET,
+			res->channel->freq_offset) ||
 	    nla_put_u32(msg, NL80211_BSS_CHAN_WIDTH, res->scan_width) ||
 	    nla_put_u32(msg, NL80211_BSS_SEEN_MS_AGO,
 			jiffies_to_msecs(jiffies - intbss->ts)))
@@ -9141,6 +9159,7 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 	enum nl80211_auth_type auth_type;
 	struct key_parse key;
 	bool local_state_change;
+	u32 freq;
 
 	if (!info->attrs[NL80211_ATTR_MAC])
 		return -EINVAL;
@@ -9197,8 +9216,12 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 		return -EOPNOTSUPP;
 
 	bssid = nla_data(info->attrs[NL80211_ATTR_MAC]);
-	chan = nl80211_get_valid_chan(&rdev->wiphy,
-				      info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+	freq = MHZ_TO_KHZ(nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+	if (info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET])
+		freq +=
+		    nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET]);
+
+	chan = nl80211_get_valid_chan(&rdev->wiphy, freq);
 	if (!chan)
 		return -EINVAL;
 
@@ -9388,6 +9411,7 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
 	struct cfg80211_assoc_request req = {};
 	const u8 *bssid, *ssid;
 	int err, ssid_len = 0;
+	u32 freq;
 
 	if (dev->ieee80211_ptr->conn_owner_nlportid &&
 	    dev->ieee80211_ptr->conn_owner_nlportid != info->snd_portid)
@@ -9407,8 +9431,11 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
 
 	bssid = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	chan = nl80211_get_valid_chan(&rdev->wiphy,
-				      info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+	freq = MHZ_TO_KHZ(nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+	if (info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET])
+		freq +=
+		    nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET]);
+	chan = nl80211_get_valid_chan(&rdev->wiphy, freq);
 	if (!chan)
 		return -EINVAL;
 
@@ -10088,6 +10115,7 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
 	struct cfg80211_connect_params connect;
 	struct wiphy *wiphy;
 	struct cfg80211_cached_keys *connkeys = NULL;
+	u32 freq = 0;
 	int err;
 
 	memset(&connect, 0, sizeof(connect));
@@ -10158,14 +10186,21 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
 		connect.prev_bssid =
 			nla_data(info->attrs[NL80211_ATTR_PREV_BSSID]);
 
-	if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
-		connect.channel = nl80211_get_valid_chan(
-			wiphy, info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+	if (info->attrs[NL80211_ATTR_WIPHY_FREQ])
+		freq = MHZ_TO_KHZ(nla_get_u32(
+					info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+	if (info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET])
+		freq +=
+		    nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ_OFFSET]);
+
+	if (freq) {
+		connect.channel = nl80211_get_valid_chan(wiphy, freq);
 		if (!connect.channel)
 			return -EINVAL;
 	} else if (info->attrs[NL80211_ATTR_WIPHY_FREQ_HINT]) {
-		connect.channel_hint = nl80211_get_valid_chan(
-			wiphy, info->attrs[NL80211_ATTR_WIPHY_FREQ_HINT]);
+		freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ_HINT]);
+		freq = MHZ_TO_KHZ(freq);
+		connect.channel_hint = nl80211_get_valid_chan(wiphy, freq);
 		if (!connect.channel_hint)
 			return -EINVAL;
 	}
@@ -16215,6 +16250,7 @@ int nl80211_send_mgmt(struct cfg80211_registered_device *rdev,
 	    nla_put_u64_64bit(msg, NL80211_ATTR_WDEV, wdev_id(wdev),
 			      NL80211_ATTR_PAD) ||
 	    nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ, KHZ_TO_MHZ(freq)) ||
+	    nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ_OFFSET, freq % 1000) ||
 	    (sig_dbm &&
 	     nla_put_u32(msg, NL80211_ATTR_RX_SIGNAL_DBM, sig_dbm)) ||
 	    nla_put(msg, NL80211_ATTR_FRAME, len, buf) ||
@@ -16864,8 +16900,10 @@ void cfg80211_report_obss_beacon_khz(struct wiphy *wiphy, const u8 *frame,
 
 		if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||
 		    (freq &&
-		     nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ,
-				 KHZ_TO_MHZ(freq))) ||
+		     (nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ,
+				  KHZ_TO_MHZ(freq)) ||
+		      nla_put_u32(msg, NL80211_ATTR_WIPHY_FREQ_OFFSET,
+				  freq % 1000))) ||
 		    (sig_dbm &&
 		     nla_put_u32(msg, NL80211_ATTR_RX_SIGNAL_DBM, sig_dbm)) ||
 		    nla_put(msg, NL80211_ATTR_FRAME, len, frame))