[RFC 1/1] RFC: allow mac address change on up iface

[James Prestwood <prestwoj@gmail.com>]

---
 .../net/wireless/intel/iwlwifi/mvm/mac80211.c |  2 ++
 include/net/cfg80211.h                        |  1 +
 include/uapi/linux/nl80211.h                  |  3 +++
 net/mac80211/iface.c                          |  5 ++---
 net/wireless/nl80211.c                        |  9 +++++++++
 net/wireless/sme.c                            | 20 +++++++++++++++++++
 6 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index fdbabca0280e..410daeb78208 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -601,6 +601,8 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 	wiphy_ext_feature_set(hw->wiphy, NL80211_EXT_FEATURE_VHT_IBSS);
 	hw->wiphy->features |= NL80211_FEATURE_HT_IBSS;
 
+	wiphy_ext_feature_set(hw->wiphy, NL80211_EXT_FEATURE_LIVE_ADDR_CHANGE);
+
 	hw->wiphy->regulatory_flags |= REGULATORY_ENABLE_RELAX_NO_IR;
 	if (iwl_mvm_is_lar_supported(mvm))
 		hw->wiphy->regulatory_flags |= REGULATORY_WIPHY_SELF_MANAGED;
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 8fb5be3ca0ca..e067db9f61b9 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2433,6 +2433,7 @@ struct cfg80211_connect_params {
 	const u8 *fils_erp_rrk;
 	size_t fils_erp_rrk_len;
 	bool want_1x;
+	const u8 *random_mac;
 };
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 6f09d1500960..da7d770a6bf2 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2794,6 +2794,8 @@ enum nl80211_attrs {
 	NL80211_ATTR_STA_TX_POWER_SETTING,
 	NL80211_ATTR_STA_TX_POWER,
 
+	NL80211_ATTR_RANDOM_MAC_ADDR,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -5466,6 +5468,7 @@ enum nl80211_ext_feature_index {
 	NL80211_EXT_FEATURE_SCHED_SCAN_BAND_SPECIFIC_RSSI_THOLD,
 	NL80211_EXT_FEATURE_EXT_KEY_ID,
 	NL80211_EXT_FEATURE_STA_TX_PWR,
+	NL80211_EXT_FEATURE_LIVE_ADDR_CHANGE,
 
 	/* add new features before the definition below */
 	NUM_NL80211_EXT_FEATURES,
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 06aac0aaae64..63d7b14189b0 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -205,9 +205,6 @@ static int ieee80211_change_mac(struct net_device *dev, void *addr)
 	bool check_dup = true;
 	int ret;
 
-	if (ieee80211_sdata_running(sdata))
-		return -EBUSY;
-
 	if (sdata->vif.type == NL80211_IFTYPE_MONITOR &&
 	    !(sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE))
 		check_dup = false;
@@ -216,6 +213,8 @@ static int ieee80211_change_mac(struct net_device *dev, void *addr)
 	if (ret)
 		return ret;
 
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+
 	ret = eth_mac_addr(dev, sa);
 
 	if (ret == 0)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 520d437aa8d1..bc975e49cd00 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -9887,6 +9887,15 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
 		connect.flags |= CONNECT_REQ_EXTERNAL_AUTH_SUPPORT;
 	}
 
+	if (info->attrs[NL80211_ATTR_RANDOM_MAC_ADDR]) {
+		if (!wiphy_ext_feature_isset(wiphy,
+					NL80211_EXT_FEATURE_LIVE_ADDR_CHANGE))
+			return -EINVAL;
+
+		connect.random_mac = nla_data(
+				info->attrs[NL80211_ATTR_RANDOM_MAC_ADDR]);
+	}
+
 	wdev_lock(dev->ieee80211_ptr);
 
 	err = cfg80211_connect(rdev, dev, &connect, connkeys,
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 7d34cb884840..8a09aad19752 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -1218,6 +1218,26 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev,
 	wdev->conn_bss_type = connect->pbss ? IEEE80211_BSS_TYPE_PBSS :
 					      IEEE80211_BSS_TYPE_ESS;
 
+	if (connect->random_mac) {
+		struct sockaddr *sa;
+		int len;
+
+		len = sizeof(sa_family_t) + max_t(size_t, dev->addr_len,
+						  sizeof(*sa));
+		sa = kmalloc(len, GFP_KERNEL);
+		if (!sa)
+			return -ENOMEM;
+
+		sa->sa_family = dev->type;
+		memcpy(sa->sa_data, connect->random_mac,
+			dev->addr_len);
+
+		err = dev_set_mac_address(dev, sa, NULL);
+		kfree(sa);
+		if (err < 0)
+			return err;
+	}
+
 	if (!rdev->ops->connect)
 		err = cfg80211_sme_connect(wdev, connect, prev_bssid);
 	else
-- 
2.17.1