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>

1 files changed, 256 insertions, 1 deletions

diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index abf6b0a047d..ffc98a8d6e5 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);