1 files changed, 132 insertions, 39 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 01da83ddcff7..aaa1aad566cd 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -589,6 +589,7 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
                 i++;
                 NLA_PUT_U32(msg, i, NL80211_CMD_SET_WIPHY_NETNS);
         }
+        CMD(set_channel, SET_CHANNEL);
 
 #undef CMD
 
@@ -689,10 +690,90 @@ static int parse_txq_params(struct nlattr *tb[],
         return 0;
 }
 
+static bool nl80211_can_set_dev_channel(struct wireless_dev *wdev)
+{
+        /*
+         * You can only set the channel explicitly for AP, mesh
+         * and WDS type interfaces; all others have their channel
+         * managed via their respective "establish a connection"
+         * command (connect, join, ...)
+         *
+         * Monitors are special as they are normally slaved to
+         * whatever else is going on, so they behave as though
+         * you tried setting the wiphy channel itself.
+         */
+        return !wdev ||
+                wdev->iftype == NL80211_IFTYPE_AP ||
+                wdev->iftype == NL80211_IFTYPE_WDS ||
+                wdev->iftype == NL80211_IFTYPE_MESH_POINT ||
+                wdev->iftype == NL80211_IFTYPE_MONITOR;
+}
+
+static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
+                                 struct wireless_dev *wdev,
+                                 struct genl_info *info)
+{
+        enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
+        u32 freq;
+        int result;
+
+        if (!info->attrs[NL80211_ATTR_WIPHY_FREQ])
+                return -EINVAL;
+
+        if (!nl80211_can_set_dev_channel(wdev))
+                return -EOPNOTSUPP;
+
+        if (info->attrs[NL80211_ATTR_WIPHY_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_HT40PLUS &&
+                    channel_type != NL80211_CHAN_HT40MINUS)
+                        return -EINVAL;
+        }
+
+        freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
+
+        mutex_lock(&rdev->devlist_mtx);
+        if (wdev) {
+                wdev_lock(wdev);
+                result = cfg80211_set_freq(rdev, wdev, freq, channel_type);
+                wdev_unlock(wdev);
+        } else {
+                result = cfg80211_set_freq(rdev, NULL, freq, channel_type);
+        }
+        mutex_unlock(&rdev->devlist_mtx);
+
+        return result;
+}
+
+static int nl80211_set_channel(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg80211_registered_device *rdev;
+        struct net_device *netdev;
+        int result;
+
+        rtnl_lock();
+
+        result = get_rdev_dev_by_info_ifindex(info, &rdev, &netdev);
+        if (result)
+                goto unlock;
+
+        result = __nl80211_set_channel(rdev, netdev->ieee80211_ptr, info);
+
+ unlock:
+        rtnl_unlock();
+
+        return result;
+}
+
 static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev;
-        int result = 0, rem_txq_params = 0;
+        struct net_device *netdev = NULL;
+        struct wireless_dev *wdev;
+        int result, rem_txq_params = 0;
         struct nlattr *nl_txq_params;
         u32 changed;
         u8 retry_short = 0, retry_long = 0;
@@ -701,16 +782,50 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 
         rtnl_lock();
 
+        /*
+         * Try to find the wiphy and netdev. Normally this
+         * function shouldn't need the netdev, but this is
+         * done for backward compatibility -- previously
+         * setting the channel was done per wiphy, but now
+         * it is per netdev. Previous userland like hostapd
+         * also passed a netdev to set_wiphy, so that it is
+         * possible to let that go to the right netdev!
+         */
         mutex_lock(&cfg80211_mutex);
 
-        rdev = __cfg80211_rdev_from_info(info);
-        if (IS_ERR(rdev)) {
-                mutex_unlock(&cfg80211_mutex);
-                result = PTR_ERR(rdev);
-                goto unlock;
+        if (info->attrs[NL80211_ATTR_IFINDEX]) {
+                int ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
+
+                netdev = dev_get_by_index(genl_info_net(info), ifindex);
+                if (netdev && netdev->ieee80211_ptr) {
+                        rdev = wiphy_to_dev(netdev->ieee80211_ptr->wiphy);
+                        mutex_lock(&rdev->mtx);
+                } else
+                        netdev = NULL;
         }
 
-        mutex_lock(&rdev->mtx);
+        if (!netdev) {
+                rdev = __cfg80211_rdev_from_info(info);
+                if (IS_ERR(rdev)) {
+                        mutex_unlock(&cfg80211_mutex);
+                        result = PTR_ERR(rdev);
+                        goto unlock;
+                }
+                wdev = NULL;
+                netdev = NULL;
+                result = 0;
+
+                mutex_lock(&rdev->mtx);
+        } else if (netif_running(netdev) &&
+                   nl80211_can_set_dev_channel(netdev->ieee80211_ptr))
+                wdev = netdev->ieee80211_ptr;
+        else
+                wdev = NULL;
+
+        /*
+         * end workaround code, by now the rdev is available
+         * and locked, and wdev may or may not be NULL.
+         */
 
         if (info->attrs[NL80211_ATTR_WIPHY_NAME])
                 result = cfg80211_dev_rename(
@@ -749,26 +864,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
         }
 
         if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
-                enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
-                u32 freq;
-
-                result = -EINVAL;
-
-                if (info->attrs[NL80211_ATTR_WIPHY_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_HT40PLUS &&
-                            channel_type != NL80211_CHAN_HT40MINUS)
-                                goto bad_res;
-                }
-
-                freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
-
-                mutex_lock(&rdev->devlist_mtx);
-                result = rdev_set_freq(rdev, NULL, freq, channel_type);
-                mutex_unlock(&rdev->devlist_mtx);
+                result = __nl80211_set_channel(rdev, wdev, info);
                 if (result)
                         goto bad_res;
         }
@@ -865,6 +961,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 
  bad_res:
         mutex_unlock(&rdev->mtx);
+        if (netdev)
+                dev_put(netdev);
  unlock:
         rtnl_unlock();
         return result;
@@ -3562,9 +3660,8 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev;
         struct net_device *dev;
-        struct wireless_dev *wdev;
         struct cfg80211_crypto_settings crypto;
-        struct ieee80211_channel *chan, *fixedchan;
+        struct ieee80211_channel *chan;
         const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
         int err, ssid_len, ie_len = 0;
         bool use_mfp = false;
@@ -3607,16 +3704,6 @@ static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
                 goto out;
         }
 
-        mutex_lock(&rdev->devlist_mtx);
-        wdev = dev->ieee80211_ptr;
-        fixedchan = rdev_fixed_channel(rdev, wdev);
-        if (fixedchan && chan != fixedchan) {
-                err = -EBUSY;
-                mutex_unlock(&rdev->devlist_mtx);
-                goto out;
-        }
-        mutex_unlock(&rdev->devlist_mtx);
-
         ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
         ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);
 
@@ -5186,6 +5273,12 @@ static struct genl_ops nl80211_ops[] = {
                 .policy = nl80211_policy,
                 .flags = GENL_ADMIN_PERM,
         },
+        {
+                .cmd = NL80211_CMD_SET_CHANNEL,
+                .doit = nl80211_set_channel,
+                .policy = nl80211_policy,
+                .flags = GENL_ADMIN_PERM,
+        },
 };
 
 static struct genl_multicast_group nl80211_mlme_mcgrp = {