2020-04-30 01:07:43

by Thomas Pedersen

[permalink] [raw]
Subject: [PATCH v3 2/5] 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 <[email protected]>

---
v2:
use NLA_POLICY_RANGE for the freq offsets (Johannes)
---
include/uapi/linux/nl80211.h | 50 +++++++++++++++---------
net/wireless/nl80211.c | 73 ++++++++++++++++++++++++++----------
2 files changed, 87 insertions(+), 36 deletions(-)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 9679d561f7d0..0ceb4de52d9a 100644
--- a/include/uapi/linux/nl80211.h
+++ b/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,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 755701132d71..fb056613a23f 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -365,6 +365,7 @@ 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),
@@ -662,6 +663,7 @@ 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 */
@@ -946,6 +948,9 @@ 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;
@@ -1351,13 +1356,11 @@ 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;
@@ -2812,13 +2815,17 @@ 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 */
@@ -2869,6 +2876,9 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
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]);
if (attrs[NL80211_ATTR_CENTER_FREQ2])
chandef->center_freq2 =
nla_get_u32(attrs[NL80211_ATTR_CENTER_FREQ2]);
@@ -3301,6 +3311,9 @@ 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:
@@ -8918,6 +8931,8 @@ 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)))
@@ -9186,6 +9201,7 @@ 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;
@@ -9242,8 +9258,12 @@ 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;

@@ -9433,6 +9453,7 @@ 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)
@@ -9452,8 +9473,11 @@ 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;

@@ -10133,6 +10157,7 @@ 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));
@@ -10203,14 +10228,21 @@ 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;
}
@@ -16257,6 +16289,7 @@ 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) ||
@@ -16906,8 +16939,10 @@ 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))
--
2.20.1