cfg80211: implement wext key handling

Move key handling wireless extension ioctls from mac80211 to cfg80211
so that all drivers that implement the cfg80211 operations get wext
compatibility.

Note that this drops the SIOCGIWENCODE ioctl support for getting
IW_ENCODE_RESTRICTED/IW_ENCODE_OPEN. This means that iwconfig will
no longer report "Security mode:open" or "Security mode:restricted"
for mac80211. However, what we displayed there (the authentication
algo used) was actually wrong -- linux/wireless.h states that this
setting is meant to differentiate between "Refuse non-encoded packets"
and "Accept non-encoded packets".

(Combined with "cfg80211: fix a couple of bugs with key ioctls". -- JWL)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 330 insertions, 41 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 15b2a179..47c20eb 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1,7 +1,7 @@
 /*
  * This is the linux wireless configuration interface.
  *
- * Copyright 2006-2008		Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2006-2009		Johannes Berg <johannes@sipsolutions.net>
  */
 
 #include <linux/if.h>
@@ -457,6 +457,10 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 				"symlink to netdev!\n");
 		}
 		dev->ieee80211_ptr->netdev = dev;
+#ifdef CONFIG_WIRELESS_EXT
+		dev->ieee80211_ptr->wext.default_key = -1;
+		dev->ieee80211_ptr->wext.default_mgmt_key = -1;
+#endif
 		mutex_unlock(&rdev->devlist_mtx);
 		break;
 	case NETDEV_GOING_DOWN:
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 3e49d33..f14b6c5 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -1,7 +1,7 @@
 /*
  * Wireless configuration interface internals.
  *
- * Copyright 2006, 2007 Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2006-2009	Johannes Berg <johannes@sipsolutions.net>
  */
 #ifndef __NET_WIRELESS_CORE_H
 #define __NET_WIRELESS_CORE_H
@@ -151,4 +151,8 @@ void cfg80211_clear_ibss(struct net_device *dev, bool nowext);
 int cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
 			struct net_device *dev, bool nowext);
 
+/* internal helpers */
+int cfg80211_validate_key_settings(struct key_params *params, int key_idx,
+				   const u8 *mac_addr);
+
 #endif /* __NET_WIRELESS_CORE_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a39e464..f88dbbe 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1,7 +1,7 @@
 /*
  * This is the new netlink-based wireless configuration interface.
  *
- * Copyright 2006, 2007	Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2006-2009	Johannes Berg <johannes@sipsolutions.net>
  */
 
 #include <linux/if.h>
@@ -1073,6 +1073,14 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	err = func(&drv->wiphy, dev, key_idx);
+#ifdef CONFIG_WIRELESS_EXT
+	if (!err) {
+		if (func == drv->ops->set_default_key)
+			dev->ieee80211_ptr->wext.default_key = key_idx;
+		else
+			dev->ieee80211_ptr->wext.default_mgmt_key = key_idx;
+	}
+#endif
 
  out:
 	cfg80211_put_dev(drv);
@@ -1111,45 +1119,9 @@ static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_MAC])
 		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	if (key_idx > 5)
+	if (cfg80211_validate_key_settings(&params, key_idx, mac_addr))
 		return -EINVAL;
 
-	/*
-	 * Disallow pairwise keys with non-zero index unless it's WEP
-	 * (because current deployments use pairwise WEP keys with
-	 * non-zero indizes but 802.11i clearly specifies to use zero)
-	 */
-	if (mac_addr && key_idx &&
-	    params.cipher != WLAN_CIPHER_SUITE_WEP40 &&
-	    params.cipher != WLAN_CIPHER_SUITE_WEP104)
-		return -EINVAL;
-
-	/* TODO: add definitions for the lengths to linux/ieee80211.h */
-	switch (params.cipher) {
-	case WLAN_CIPHER_SUITE_WEP40:
-		if (params.key_len != 5)
-			return -EINVAL;
-		break;
-	case WLAN_CIPHER_SUITE_TKIP:
-		if (params.key_len != 32)
-			return -EINVAL;
-		break;
-	case WLAN_CIPHER_SUITE_CCMP:
-		if (params.key_len != 16)
-			return -EINVAL;
-		break;
-	case WLAN_CIPHER_SUITE_WEP104:
-		if (params.key_len != 13)
-			return -EINVAL;
-		break;
-	case WLAN_CIPHER_SUITE_AES_CMAC:
-		if (params.key_len != 16)
-			return -EINVAL;
-		break;
-	default:
-		return -EINVAL;
-	}
-
 	rtnl_lock();
 
 	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -1210,6 +1182,15 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
 
 	err = drv->ops->del_key(&drv->wiphy, dev, key_idx, mac_addr);
 
+#ifdef CONFIG_WIRELESS_EXT
+	if (!err) {
+		if (key_idx == dev->ieee80211_ptr->wext.default_key)
+			dev->ieee80211_ptr->wext.default_key = -1;
+		else if (key_idx == dev->ieee80211_ptr->wext.default_mgmt_key)
+			dev->ieee80211_ptr->wext.default_mgmt_key = -1;
+	}
+#endif
+
  out:
 	cfg80211_put_dev(drv);
 	dev_put(dev);
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 5f7e997..beb226e 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -138,3 +138,48 @@ void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
 		if (wiphy->bands[band])
 			set_mandatory_flags_band(wiphy->bands[band], band);
 }
+
+int cfg80211_validate_key_settings(struct key_params *params, int key_idx,
+				   const u8 *mac_addr)
+{
+	if (key_idx > 5)
+		return -EINVAL;
+
+	/*
+	 * Disallow pairwise keys with non-zero index unless it's WEP
+	 * (because current deployments use pairwise WEP keys with
+	 * non-zero indizes but 802.11i clearly specifies to use zero)
+	 */
+	if (mac_addr && key_idx &&
+	    params->cipher != WLAN_CIPHER_SUITE_WEP40 &&
+	    params->cipher != WLAN_CIPHER_SUITE_WEP104)
+		return -EINVAL;
+
+	/* TODO: add definitions for the lengths to linux/ieee80211.h */
+	switch (params->cipher) {
+	case WLAN_CIPHER_SUITE_WEP40:
+		if (params->key_len != 5)
+			return -EINVAL;
+		break;
+	case WLAN_CIPHER_SUITE_TKIP:
+		if (params->key_len != 32)
+			return -EINVAL;
+		break;
+	case WLAN_CIPHER_SUITE_CCMP:
+		if (params->key_len != 16)
+			return -EINVAL;
+		break;
+	case WLAN_CIPHER_SUITE_WEP104:
+		if (params->key_len != 13)
+			return -EINVAL;
+		break;
+	case WLAN_CIPHER_SUITE_AES_CMAC:
+		if (params->key_len != 16)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index abf6b0a..ffc98a8 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -5,12 +5,13 @@
  * into cfg80211, when that happens all the exports here go away and
  * we directly assign the wireless handlers of wireless interfaces.
  *
- * Copyright 2008	Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2008-2009	Johannes Berg <johannes@sipsolutions.net>
  */
 
 #include <linux/wireless.h>
 #include <linux/nl80211.h>
 #include <linux/if_arp.h>
+#include <linux/etherdevice.h>
 #include <net/iw_handler.h>
 #include <net/cfg80211.h>
 #include "core.h"
@@ -477,3 +478,257 @@ int cfg80211_wext_giwretry(struct net_device *dev,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(cfg80211_wext_giwretry);
+
+static int cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
+				   struct net_device *dev, const u8 *addr,
+				   bool remove, bool tx_key, int idx,
+				   struct key_params *params)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
+
+	if (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC) {
+		if (!rdev->ops->set_default_mgmt_key)
+			return -EOPNOTSUPP;
+
+		if (idx < 4 || idx > 5)
+			return -EINVAL;
+	} else if (idx < 0 || idx > 3)
+		return -EINVAL;
+
+	if (remove) {
+		err = rdev->ops->del_key(&rdev->wiphy, dev, idx, addr);
+		if (!err) {
+			if (idx == wdev->wext.default_key)
+				wdev->wext.default_key = -1;
+			else if (idx == wdev->wext.default_mgmt_key)
+				wdev->wext.default_mgmt_key = -1;
+		}
+		return err;
+	} else {
+		if (addr)
+			tx_key = false;
+
+		if (cfg80211_validate_key_settings(params, idx, addr))
+			return -EINVAL;
+
+		err = rdev->ops->add_key(&rdev->wiphy, dev, idx, addr, params);
+		if (err)
+			return err;
+
+		if (tx_key || (!addr && wdev->wext.default_key == -1)) {
+			err = rdev->ops->set_default_key(&rdev->wiphy,
+							 dev, idx);
+			if (!err)
+				wdev->wext.default_key = idx;
+			return err;
+		}
+
+		if (params->cipher == WLAN_CIPHER_SUITE_AES_CMAC &&
+		    (tx_key || (!addr && wdev->wext.default_mgmt_key == -1))) {
+			err = rdev->ops->set_default_mgmt_key(&rdev->wiphy,
+							      dev, idx);
+			if (!err)
+				wdev->wext.default_mgmt_key = idx;
+			return err;
+		}
+
+		return 0;
+	}
+}
+
+int cfg80211_wext_siwencode(struct net_device *dev,
+			    struct iw_request_info *info,
+			    struct iw_point *erq, char *keybuf)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+	int idx, err;
+	bool remove = false;
+	struct key_params params;
+
+	/* no use -- only MFP (set_default_mgmt_key) is optional */
+	if (!rdev->ops->del_key ||
+	    !rdev->ops->add_key ||
+	    !rdev->ops->set_default_key)
+		return -EOPNOTSUPP;
+
+	idx = erq->flags & IW_ENCODE_INDEX;
+	if (idx == 0) {
+		idx = wdev->wext.default_key;
+		if (idx < 0)
+			idx = 0;
+	} else if (idx < 1 || idx > 4)
+		return -EINVAL;
+	else
+		idx--;
+
+	if (erq->flags & IW_ENCODE_DISABLED)
+		remove = true;
+	else if (erq->length == 0) {
+		/* No key data - just set the default TX key index */
+		err = rdev->ops->set_default_key(&rdev->wiphy, dev, idx);
+		if (!err)
+			wdev->wext.default_key = idx;
+		return err;
+	}
+
+	memset(&params, 0, sizeof(params));
+	params.key = keybuf;
+	params.key_len = erq->length;
+	if (erq->length == 5)
+		params.cipher = WLAN_CIPHER_SUITE_WEP40;
+	else if (erq->length == 13)
+		params.cipher = WLAN_CIPHER_SUITE_WEP104;
+	else if (!remove)
+		return -EINVAL;
+
+	return cfg80211_set_encryption(rdev, dev, NULL, remove,
+				       wdev->wext.default_key == -1,
+				       idx, &params);
+}
+EXPORT_SYMBOL_GPL(cfg80211_wext_siwencode);
+
+int cfg80211_wext_siwencodeext(struct net_device *dev,
+			       struct iw_request_info *info,
+			       struct iw_point *erq, char *extra)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+	struct iw_encode_ext *ext = (struct iw_encode_ext *) extra;
+	const u8 *addr;
+	int idx;
+	bool remove = false;
+	struct key_params params;
+	u32 cipher;
+
+	/* no use -- only MFP (set_default_mgmt_key) is optional */
+	if (!rdev->ops->del_key ||
+	    !rdev->ops->add_key ||
+	    !rdev->ops->set_default_key)
+		return -EOPNOTSUPP;
+
+	switch (ext->alg) {
+	case IW_ENCODE_ALG_NONE:
+		remove = true;
+		cipher = 0;
+		break;
+	case IW_ENCODE_ALG_WEP:
+		if (ext->key_len == 5)
+			cipher = WLAN_CIPHER_SUITE_WEP40;
+		else if (ext->key_len == 13)
+			cipher = WLAN_CIPHER_SUITE_WEP104;
+		else
+			return -EINVAL;
+		break;
+	case IW_ENCODE_ALG_TKIP:
+		cipher = WLAN_CIPHER_SUITE_TKIP;
+		break;
+	case IW_ENCODE_ALG_CCMP:
+		cipher = WLAN_CIPHER_SUITE_CCMP;
+		break;
+	case IW_ENCODE_ALG_AES_CMAC:
+		cipher = WLAN_CIPHER_SUITE_AES_CMAC;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	if (erq->flags & IW_ENCODE_DISABLED)
+		remove = true;
+
+	idx = erq->flags & IW_ENCODE_INDEX;
+	if (cipher == WLAN_CIPHER_SUITE_AES_CMAC) {
+		if (idx < 4 || idx > 5) {
+			idx = wdev->wext.default_mgmt_key;
+			if (idx < 0)
+				return -EINVAL;
+		} else
+			idx--;
+	} else {
+		if (idx < 1 || idx > 4) {
+			idx = wdev->wext.default_key;
+			if (idx < 0)
+				return -EINVAL;
+		} else
+			idx--;
+	}
+
+	addr = ext->addr.sa_data;
+	if (is_broadcast_ether_addr(addr))
+		addr = NULL;
+
+	memset(&params, 0, sizeof(params));
+	params.key = ext->key;
+	params.key_len = ext->key_len;
+	params.cipher = cipher;
+
+	return cfg80211_set_encryption(
+			rdev, dev, addr, remove,
+			ext->ext_flags & IW_ENCODE_EXT_SET_TX_KEY,
+			idx, &params);
+}
+EXPORT_SYMBOL_GPL(cfg80211_wext_siwencodeext);
+
+struct giwencode_cookie {
+	size_t buflen;
+	char *keybuf;
+};
+
+static void giwencode_get_key_cb(void *cookie, struct key_params *params)
+{
+	struct giwencode_cookie *data = cookie;
+
+	if (!params->key) {
+		data->buflen = 0;
+		return;
+	}
+
+	data->buflen = min_t(size_t, data->buflen, params->key_len);
+	memcpy(data->keybuf, params->key, data->buflen);
+}
+
+int cfg80211_wext_giwencode(struct net_device *dev,
+			    struct iw_request_info *info,
+			    struct iw_point *erq, char *keybuf)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+	int idx, err;
+	struct giwencode_cookie data = {
+		.keybuf = keybuf,
+		.buflen = erq->length,
+	};
+
+	if (!rdev->ops->get_key)
+		return -EOPNOTSUPP;
+
+	idx = erq->flags & IW_ENCODE_INDEX;
+	if (idx == 0) {
+		idx = wdev->wext.default_key;
+		if (idx < 0)
+			idx = 0;
+	} else if (idx < 1 || idx > 4)
+		return -EINVAL;
+	else
+		idx--;
+
+	erq->flags = idx + 1;
+
+	err = rdev->ops->get_key(&rdev->wiphy, dev, idx, NULL, &data,
+				 giwencode_get_key_cb);
+	if (!err) {
+		erq->length = data.buflen;
+		erq->flags |= IW_ENCODE_ENABLED;
+		return 0;
+	}
+
+	if (err == -ENOENT) {
+		erq->flags |= IW_ENCODE_DISABLED;
+		erq->length = 0;
+		return 0;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(cfg80211_wext_giwencode);