nl80211: Parse channel type attribute in an ibss join request

Prepare cfg80211 for IBSS HT:
 * extend cfg80211 ibss struct with channel_type
 * Check if extension channel can be used
 * Export can_beacon_sec_chan for use in mac80211 (will be called
   from ibss.c later).

Signed-off-by: Alexander Simon <an.alexsimon@googlemail.com>
[siwu@hrz.tu-chemnitz.de: Updates]
* fix cfg80211_can_beacon_ext_chan comment
* remove implicit channel_type enum assumptions
* remove radar channel flags check
* add HT IBSS feature flag
* reword commit message

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index f51e3bf..a187606 100644 (file)
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -2785,9 +2785,11 @@ enum nl80211_ap_sme_features {
  * @NL80211_FEATURE_SK_TX_STATUS: This driver supports reflecting back
  *     TX status to the socket error queue when requested with the
  *     socket option.
+ * @NL80211_FEATURE_HT_IBSS: This driver supports IBSS with HT datarates.
  */
 enum nl80211_feature_flags {
        NL80211_FEATURE_SK_TX_STATUS    = 1 << 0,
+       NL80211_FEATURE_HT_IBSS         = 1 << 1,
 };
 
 /**

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index f0e82b2..3de1c39 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1149,6 +1149,7 @@ struct cfg80211_ibss_params {
        u8 *ssid;
        u8 *bssid;
        struct ieee80211_channel *channel;
+       enum nl80211_channel_type channel_type;
        u8 *ie;
        u8 ssid_len, ie_len;
        u16 beacon_interval;
@@ -3267,6 +3268,16 @@ void cfg80211_report_obss_beacon(struct wiphy *wiphy,
                                 const u8 *frame, size_t len,
                                 int freq, gfp_t gfp);
 
+/*
+ * cfg80211_can_beacon_sec_chan - test if ht40 on extension channel can be used
+ * @wiphy: the wiphy
+ * @chan: main channel
+ * @channel_type: HT mode
+ */
+int cfg80211_can_beacon_sec_chan(struct wiphy *wiphy,
+                                struct ieee80211_channel *chan,
+                                enum nl80211_channel_type channel_type);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */

diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 17cd0c0..2fcfe09 100644 (file)
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -6,6 +6,7 @@
  * Copyright 2009      Johannes Berg <johannes@sipsolutions.net>
  */
 
+#include <linux/export.h>
 #include <net/cfg80211.h>
 #include "core.h"
 
@@ -44,9 +45,9 @@ rdev_freq_to_chan(struct cfg80211_registered_device *rdev,
        return chan;
 }
 
-static bool can_beacon_sec_chan(struct wiphy *wiphy,
-                               struct ieee80211_channel *chan,
-                               enum nl80211_channel_type channel_type)
+int cfg80211_can_beacon_sec_chan(struct wiphy *wiphy,
+                                 struct ieee80211_channel *chan,
+                                 enum nl80211_channel_type channel_type)
 {
        struct ieee80211_channel *sec_chan;
        int diff;
@@ -75,6 +76,7 @@ static bool can_beacon_sec_chan(struct wiphy *wiphy,
 
        return true;
 }
+EXPORT_SYMBOL(cfg80211_can_beacon_sec_chan);
 
 int cfg80211_set_freq(struct cfg80211_registered_device *rdev,
                      struct wireless_dev *wdev, int freq,
@@ -109,8 +111,8 @@ int cfg80211_set_freq(struct cfg80211_registered_device *rdev,
                switch (channel_type) {
                case NL80211_CHAN_HT40PLUS:
                case NL80211_CHAN_HT40MINUS:
-                       if (!can_beacon_sec_chan(&rdev->wiphy, chan,
-                                                channel_type)) {
+                       if (!cfg80211_can_beacon_sec_chan(&rdev->wiphy, chan,
+                                                         channel_type)) {
                                printk(KERN_DEBUG
                                       "cfg80211: Secondary channel not "
                                       "allowed to initiate communication\n");

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 8a9b4d8..ba43966 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4682,13 +4682,41 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
                ibss.ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
        }
 
-       ibss.channel = ieee80211_get_channel(wiphy,
-               nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+       if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
+               enum nl80211_channel_type channel_type;
+
+               channel_type = nla_get_u32(
+                               info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]);
+               if (channel_type != NL80211_CHAN_NO_HT &&
+                   channel_type != NL80211_CHAN_HT20 &&
+                   channel_type != NL80211_CHAN_HT40MINUS &&
+                   channel_type != NL80211_CHAN_HT40PLUS)
+                       return -EINVAL;
+
+               if (channel_type != NL80211_CHAN_NO_HT &&
+                   !(wiphy->features & NL80211_FEATURE_HT_IBSS))
+                       return -EINVAL;
+
+               ibss.channel_type = channel_type;
+       } else {
+               ibss.channel_type = NL80211_CHAN_NO_HT;
+       }
+
+       ibss.channel = rdev_freq_to_chan(rdev,
+               nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]),
+               ibss.channel_type);
        if (!ibss.channel ||
            ibss.channel->flags & IEEE80211_CHAN_NO_IBSS ||
            ibss.channel->flags & IEEE80211_CHAN_DISABLED)
                return -EINVAL;
 
+       /* Both channels should be able to initiate communication */
+       if ((ibss.channel_type == NL80211_CHAN_HT40PLUS ||
+            ibss.channel_type == NL80211_CHAN_HT40MINUS) &&
+           !cfg80211_can_beacon_sec_chan(&rdev->wiphy, ibss.channel,
+                                         ibss.channel_type))
+               return -EINVAL;
+
        ibss.channel_fixed = !!info->attrs[NL80211_ATTR_FREQ_FIXED];
        ibss.privacy = !!info->attrs[NL80211_ATTR_PRIVACY];