nl80211/cfg80211: add 5 and 10 MHz defines and wiphy flag

Add defines for 5 and 10 MHz channel width and fix channel
handling functions accordingly.

Also check for and report the WIPHY_FLAG_SUPPORTS_5_10_MHZ
capability.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[fix spelling in comment]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

4 files changed, 72 insertions, 12 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 6a43c34ce96f..316f34bb8e6e 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2342,6 +2342,7 @@ struct cfg80211_ops {
  *      responds to probe-requests in hardware.
  * @WIPHY_FLAG_OFFCHAN_TX: Device supports direct off-channel TX.
  * @WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL: Device supports remain-on-channel call.
+ * @WIPHY_FLAG_SUPPORTS_5_10_MHZ: Device supports 5 MHz and 10 MHz channels.
  */
 enum wiphy_flags {
         WIPHY_FLAG_CUSTOM_REGULATORY            = BIT(0),
@@ -2365,6 +2366,7 @@ enum wiphy_flags {
         WIPHY_FLAG_AP_PROBE_RESP_OFFLOAD        = BIT(19),
         WIPHY_FLAG_OFFCHAN_TX                   = BIT(20),
         WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL        = BIT(21),
+        WIPHY_FLAG_SUPPORTS_5_10_MHZ            = BIT(22),
 };
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index ca6facf4df0c..861e5eba3953 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2758,6 +2758,8 @@ enum nl80211_channel_type {
  *      and %NL80211_ATTR_CENTER_FREQ2 attributes must be provided as well
  * @NL80211_CHAN_WIDTH_160: 160 MHz channel, the %NL80211_ATTR_CENTER_FREQ1
  *      attribute must be provided as well
+ * @NL80211_CHAN_WIDTH_5: 5 MHz OFDM channel
+ * @NL80211_CHAN_WIDTH_10: 10 MHz OFDM channel
  */
 enum nl80211_chan_width {
         NL80211_CHAN_WIDTH_20_NOHT,
@@ -2766,6 +2768,8 @@ enum nl80211_chan_width {
         NL80211_CHAN_WIDTH_80,
         NL80211_CHAN_WIDTH_80P80,
         NL80211_CHAN_WIDTH_160,
+        NL80211_CHAN_WIDTH_5,
+        NL80211_CHAN_WIDTH_10,
 };
 
 /**
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index fd556ac05fdb..50f6195c8b70 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -54,6 +54,8 @@ bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
         control_freq = chandef->chan->center_freq;
 
         switch (chandef->width) {
+        case NL80211_CHAN_WIDTH_5:
+        case NL80211_CHAN_WIDTH_10:
         case NL80211_CHAN_WIDTH_20:
         case NL80211_CHAN_WIDTH_20_NOHT:
                 if (chandef->center_freq1 != control_freq)
@@ -152,6 +154,12 @@ static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
         int width;
 
         switch (c->width) {
+        case NL80211_CHAN_WIDTH_5:
+                width = 5;
+                break;
+        case NL80211_CHAN_WIDTH_10:
+                width = 10;
+                break;
         case NL80211_CHAN_WIDTH_20:
         case NL80211_CHAN_WIDTH_20_NOHT:
                 width = 20;
@@ -194,6 +202,16 @@ cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
         if (c1->width == c2->width)
                 return NULL;
 
+        /*
+         * can't be compatible if one of them is 5 or 10 MHz,
+         * but they don't have the same width.
+         */
+        if (c1->width == NL80211_CHAN_WIDTH_5 ||
+            c1->width == NL80211_CHAN_WIDTH_10 ||
+            c2->width == NL80211_CHAN_WIDTH_5 ||
+            c2->width == NL80211_CHAN_WIDTH_10)
+                return NULL;
+
         if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
             c1->width == NL80211_CHAN_WIDTH_20)
                 return c2;
@@ -264,11 +282,17 @@ static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
                                             u32 bandwidth)
 {
         struct ieee80211_channel *c;
-        u32 freq;
+        u32 freq, start_freq, end_freq;
+
+        if (bandwidth <= 20) {
+                start_freq = center_freq;
+                end_freq = center_freq;
+        } else {
+                start_freq = center_freq - bandwidth/2 + 10;
+                end_freq = center_freq + bandwidth/2 - 10;
+        }
 
-        for (freq = center_freq - bandwidth/2 + 10;
-             freq <= center_freq + bandwidth/2 - 10;
-             freq += 20) {
+        for (freq = start_freq; freq <= end_freq; freq += 20) {
                 c = ieee80211_get_channel(wiphy, freq);
                 if (!c)
                         return -EINVAL;
@@ -310,11 +334,17 @@ static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
                                         u32 prohibited_flags)
 {
         struct ieee80211_channel *c;
-        u32 freq;
+        u32 freq, start_freq, end_freq;
+
+        if (bandwidth <= 20) {
+                start_freq = center_freq;
+                end_freq = center_freq;
+        } else {
+                start_freq = center_freq - bandwidth/2 + 10;
+                end_freq = center_freq + bandwidth/2 - 10;
+        }
 
-        for (freq = center_freq - bandwidth/2 + 10;
-             freq <= center_freq + bandwidth/2 - 10;
-             freq += 20) {
+        for (freq = start_freq; freq <= end_freq; freq += 20) {
                 c = ieee80211_get_channel(wiphy, freq);
                 if (!c)
                         return false;
@@ -349,6 +379,12 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
         control_freq = chandef->chan->center_freq;
 
         switch (chandef->width) {
+        case NL80211_CHAN_WIDTH_5:
+                width = 5;
+                break;
+        case NL80211_CHAN_WIDTH_10:
+                width = 10;
+                break;
         case NL80211_CHAN_WIDTH_20:
                 if (!ht_cap->ht_supported)
                         return false;
@@ -405,6 +441,11 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy,
         if (width > 20)
                 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
 
+        /* 5 and 10 MHz are only defined for the OFDM PHY */
+        if (width < 20)
+                prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
+
+
         if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
                                          width, prohibited_flags))
                 return false;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 1c4f7daea6c7..4ab1ffa9df11 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1188,6 +1188,9 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev,
                 if ((dev->wiphy.flags & WIPHY_FLAG_TDLS_EXTERNAL_SETUP) &&
                     nla_put_flag(msg, NL80211_ATTR_TDLS_EXTERNAL_SETUP))
                         goto nla_put_failure;
+                if ((dev->wiphy.flags & WIPHY_FLAG_SUPPORTS_5_10_MHZ) &&
+                    nla_put_flag(msg, WIPHY_FLAG_SUPPORTS_5_10_MHZ))
+                        goto nla_put_failure;
 
                 (*split_start)++;
                 if (split)
@@ -1731,6 +1734,11 @@ static int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
                                      IEEE80211_CHAN_DISABLED))
                 return -EINVAL;
 
+        if ((chandef->width == NL80211_CHAN_WIDTH_5 ||
+             chandef->width == NL80211_CHAN_WIDTH_10) &&
+            !(rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_5_10_MHZ))
+                return -EINVAL;
+
         return 0;
 }
 
@@ -6280,11 +6288,16 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
         if (!cfg80211_reg_can_beacon(&rdev->wiphy, &ibss.chandef))
                 return -EINVAL;
 
-        if (ibss.chandef.width > NL80211_CHAN_WIDTH_40)
-                return -EINVAL;
-        if (ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
-            !(rdev->wiphy.features & NL80211_FEATURE_HT_IBSS))
+        switch (ibss.chandef.width) {
+        case NL80211_CHAN_WIDTH_20_NOHT:
+                break;
+        case NL80211_CHAN_WIDTH_20:
+        case NL80211_CHAN_WIDTH_40:
+                if (rdev->wiphy.features & NL80211_FEATURE_HT_IBSS)
+                        break;
+        default:
                 return -EINVAL;
+        }
 
         ibss.channel_fixed = !!info->attrs[NL80211_ATTR_FREQ_FIXED];
         ibss.privacy = !!info->attrs[NL80211_ATTR_PRIVACY];