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Commit 41ade00f authored by Johannes Berg's avatar Johannes Berg Committed by David S. Miller
Browse files

cfg80211/nl80211: introduce key handling 



This introduces key handling to cfg80211/nl80211. Default
and group keys can be added, changed and removed; sequence
counters for each key can be retrieved.

Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a1464ab6

include/linux/nl80211.h

+34 −0
Original line number Diff line number Diff line
@@ -37,6 +37,16 @@ 
 *	userspace to request deletion of a virtual interface, then requires

 *	attribute %NL80211_ATTR_IFINDEX.

 *

 * @NL80211_CMD_GET_KEY: Get sequence counter information for a key specified

 *	by %NL80211_ATTR_KEY_IDX and/or %NL80211_ATTR_MAC.

 * @NL80211_CMD_SET_KEY: Set key attributes %NL80211_ATTR_KEY_DEFAULT or

 *	%NL80211_ATTR_KEY_THRESHOLD.

 * @NL80211_CMD_NEW_KEY: add a key with given %NL80211_ATTR_KEY_DATA,

 *	%NL80211_ATTR_KEY_IDX, %NL80211_ATTR_MAC and %NL80211_ATTR_KEY_CIPHER

 *	attributes.

 * @NL80211_CMD_DEL_KEY: delete a key identified by %NL80211_ATTR_KEY_IDX

 *	or %NL80211_ATTR_MAC.

 *

 * @NL80211_CMD_MAX: highest used command number

 * @__NL80211_CMD_AFTER_LAST: internal use

 */
@@ -54,6 +64,11 @@ enum nl80211_commands { 
	NL80211_CMD_NEW_INTERFACE,

	NL80211_CMD_DEL_INTERFACE,



	NL80211_CMD_GET_KEY,

	NL80211_CMD_SET_KEY,

	NL80211_CMD_NEW_KEY,

	NL80211_CMD_DEL_KEY,



	/* add commands here */



	/* used to define NL80211_CMD_MAX below */
@@ -75,6 +90,17 @@ enum nl80211_commands { 
 * @NL80211_ATTR_IFNAME: network interface name

 * @NL80211_ATTR_IFTYPE: type of virtual interface, see &enum nl80211_iftype

 *

 * @NL80211_ATTR_MAC: MAC address (various uses)

 *

 * @NL80211_ATTR_KEY_DATA: (temporal) key data; for TKIP this consists of

 *	16 bytes encryption key followed by 8 bytes each for TX and RX MIC

 *	keys

 * @NL80211_ATTR_KEY_IDX: key ID (u8, 0-3)

 * @NL80211_ATTR_KEY_CIPHER: key cipher suite (u32, as defined by IEEE 802.11

 *	section 7.3.2.25.1, e.g. 0x000FAC04)

 * @NL80211_ATTR_KEY_SEQ: transmit key sequence number (IV/PN) for TKIP and

 *	CCMP keys, each six bytes in little endian

 *

 * @NL80211_ATTR_MAX: highest attribute number currently defined

 * @__NL80211_ATTR_AFTER_LAST: internal use

 */
@@ -89,6 +115,14 @@ enum nl80211_attrs { 
	NL80211_ATTR_IFNAME,

	NL80211_ATTR_IFTYPE,



	NL80211_ATTR_MAC,



	NL80211_ATTR_KEY_DATA,

	NL80211_ATTR_KEY_IDX,

	NL80211_ATTR_KEY_CIPHER,

	NL80211_ATTR_KEY_SEQ,

	NL80211_ATTR_KEY_DEFAULT,



	/* add attributes here, update the policy in nl80211.c */



	__NL80211_ATTR_AFTER_LAST,

include/net/cfg80211.h

+44 −0
Original line number Diff line number Diff line
@@ -49,6 +49,26 @@ extern int ieee80211_radiotap_iterator_next( 
   struct ieee80211_radiotap_iterator *iterator);





 /**

 * struct key_params - key information

 *

 * Information about a key

 *

 * @key: key material

 * @key_len: length of key material

 * @cipher: cipher suite selector

 * @seq: sequence counter (IV/PN) for TKIP and CCMP keys, only used

 *	with the get_key() callback, must be in little endian,

 *	length given by @seq_len.

 */

struct key_params {

	u8 *key;

	u8 *seq;

	int key_len;

	int seq_len;

	u32 cipher;

};



/* from net/wireless.h */

struct wiphy;
@@ -71,6 +91,18 @@ struct wiphy; 
 *

 * @change_virtual_intf: change type of virtual interface

 *

 * @add_key: add a key with the given parameters. @mac_addr will be %NULL

 *	when adding a group key.

 *

 * @get_key: get information about the key with the given parameters.

 *	@mac_addr will be %NULL when requesting information for a group

 *	key. All pointers given to the @callback function need not be valid

 *	after it returns.

 *

 * @del_key: remove a key given the @mac_addr (%NULL for a group key)

 *	and @key_index

 *

 * @set_default_key: set the default key on an interface

 */

struct cfg80211_ops {

	int	(*add_virtual_intf)(struct wiphy *wiphy, char *name,
@@ -78,6 +110,18 @@ struct cfg80211_ops { 
	int	(*del_virtual_intf)(struct wiphy *wiphy, int ifindex);

	int	(*change_virtual_intf)(struct wiphy *wiphy, int ifindex,

				       enum nl80211_iftype type);



	int	(*add_key)(struct wiphy *wiphy, struct net_device *netdev,

			   u8 key_index, u8 *mac_addr,

			   struct key_params *params);

	int	(*get_key)(struct wiphy *wiphy, struct net_device *netdev,

			   u8 key_index, u8 *mac_addr, void *cookie,

			   void (*callback)(void *cookie, struct key_params*));

	int	(*del_key)(struct wiphy *wiphy, struct net_device *netdev,

			   u8 key_index, u8 *mac_addr);

	int	(*set_default_key)(struct wiphy *wiphy,

				   struct net_device *netdev,

				   u8 key_index);

};



#endif /* __NET_CFG80211_H */

net/wireless/core.c

+3 −0
Original line number Diff line number Diff line
@@ -184,6 +184,9 @@ struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv) 
	struct cfg80211_registered_device *drv;

	int alloc_size;



	WARN_ON(!ops->add_key && ops->del_key);

	WARN_ON(ops->add_key && !ops->del_key);



	alloc_size = sizeof(*drv) + sizeof_priv;



	drv = kzalloc(alloc_size, GFP_KERNEL);

net/wireless/nl80211.c

+289 −0
Original line number Diff line number Diff line
@@ -61,6 +61,14 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = { 
	[NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },

	[NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },

	[NL80211_ATTR_IFNAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ-1 },



	[NL80211_ATTR_MAC] = { .type = NLA_BINARY, .len = ETH_ALEN },



	[NL80211_ATTR_KEY_DATA] = { .type = NLA_BINARY,

				    .len = WLAN_MAX_KEY_LEN },

	[NL80211_ATTR_KEY_IDX] = { .type = NLA_U8 },

	[NL80211_ATTR_KEY_CIPHER] = { .type = NLA_U32 },

	[NL80211_ATTR_KEY_DEFAULT] = { .type = NLA_FLAG },

};



/* message building helper */
@@ -335,6 +343,263 @@ static int nl80211_del_interface(struct sk_buff *skb, struct genl_info *info) 
	return err;

}



struct get_key_cookie {

	struct sk_buff *msg;

	int error;

};



static void get_key_callback(void *c, struct key_params *params)

{

	struct get_key_cookie *cookie = c;



	if (params->key)

		NLA_PUT(cookie->msg, NL80211_ATTR_KEY_DATA,

			params->key_len, params->key);



	if (params->seq)

		NLA_PUT(cookie->msg, NL80211_ATTR_KEY_SEQ,

			params->seq_len, params->seq);



	if (params->cipher)

		NLA_PUT_U32(cookie->msg, NL80211_ATTR_KEY_CIPHER,

			    params->cipher);



	return;

 nla_put_failure:

	cookie->error = 1;

}



static int nl80211_get_key(struct sk_buff *skb, struct genl_info *info)

{

	struct cfg80211_registered_device *drv;

	int err;

	struct net_device *dev;

	u8 key_idx = 0;

	u8 *mac_addr = NULL;

	struct get_key_cookie cookie = {

		.error = 0,

	};

	void *hdr;

	struct sk_buff *msg;



	if (info->attrs[NL80211_ATTR_KEY_IDX])

		key_idx = nla_get_u8(info->attrs[NL80211_ATTR_KEY_IDX]);



	if (key_idx > 3)

		return -EINVAL;



	if (info->attrs[NL80211_ATTR_MAC])

		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);



	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);

	if (err)

		return err;



	if (!drv->ops->get_key) {

		err = -EOPNOTSUPP;

		goto out;

	}



	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!msg) {

		err = -ENOMEM;

		goto out;

	}



	hdr = nl80211hdr_put(msg, info->snd_pid, info->snd_seq, 0,

			     NL80211_CMD_NEW_KEY);



	if (IS_ERR(hdr)) {

		err = PTR_ERR(hdr);

		goto out;

	}



	cookie.msg = msg;



	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);

	NLA_PUT_U8(msg, NL80211_ATTR_KEY_IDX, key_idx);

	if (mac_addr)

		NLA_PUT(msg, NL80211_ATTR_MAC, ETH_ALEN, mac_addr);



	rtnl_lock();

	err = drv->ops->get_key(&drv->wiphy, dev, key_idx, mac_addr,

				&cookie, get_key_callback);

	rtnl_unlock();



	if (err)

		goto out;



	if (cookie.error)

		goto nla_put_failure;



	genlmsg_end(msg, hdr);

	err = genlmsg_unicast(msg, info->snd_pid);

	goto out;



 nla_put_failure:

	err = -ENOBUFS;

	nlmsg_free(msg);

 out:

	cfg80211_put_dev(drv);

	dev_put(dev);

	return err;

}



static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)

{

	struct cfg80211_registered_device *drv;

	int err;

	struct net_device *dev;

	u8 key_idx;



	if (!info->attrs[NL80211_ATTR_KEY_IDX])

		return -EINVAL;



	key_idx = nla_get_u8(info->attrs[NL80211_ATTR_KEY_IDX]);



	if (key_idx > 3)

		return -EINVAL;



	/* currently only support setting default key */

	if (!info->attrs[NL80211_ATTR_KEY_DEFAULT])

		return -EINVAL;



	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);

	if (err)

		return err;



	if (!drv->ops->set_default_key) {

		err = -EOPNOTSUPP;

		goto out;

	}



	rtnl_lock();

	err = drv->ops->set_default_key(&drv->wiphy, dev, key_idx);

	rtnl_unlock();



 out:

	cfg80211_put_dev(drv);

	dev_put(dev);

	return err;

}



static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)

{

	struct cfg80211_registered_device *drv;

	int err;

	struct net_device *dev;

	struct key_params params;

	u8 key_idx = 0;

	u8 *mac_addr = NULL;



	memset(&params, 0, sizeof(params));



	if (!info->attrs[NL80211_ATTR_KEY_CIPHER])

		return -EINVAL;



	if (info->attrs[NL80211_ATTR_KEY_DATA]) {

		params.key = nla_data(info->attrs[NL80211_ATTR_KEY_DATA]);

		params.key_len = nla_len(info->attrs[NL80211_ATTR_KEY_DATA]);

	}



	if (info->attrs[NL80211_ATTR_KEY_IDX])

		key_idx = nla_get_u8(info->attrs[NL80211_ATTR_KEY_IDX]);



	params.cipher = nla_get_u32(info->attrs[NL80211_ATTR_KEY_CIPHER]);



	if (info->attrs[NL80211_ATTR_MAC])

		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);



	if (key_idx > 3)

		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;

	default:

		return -EINVAL;

	}



	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);

	if (err)

		return err;



	if (!drv->ops->add_key) {

		err = -EOPNOTSUPP;

		goto out;

	}



	rtnl_lock();

	err = drv->ops->add_key(&drv->wiphy, dev, key_idx, mac_addr, &params);

	rtnl_unlock();



 out:

	cfg80211_put_dev(drv);

	dev_put(dev);

	return err;

}



static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)

{

	struct cfg80211_registered_device *drv;

	int err;

	struct net_device *dev;

	u8 key_idx = 0;

	u8 *mac_addr = NULL;



	if (info->attrs[NL80211_ATTR_KEY_IDX])

		key_idx = nla_get_u8(info->attrs[NL80211_ATTR_KEY_IDX]);



	if (key_idx > 3)

		return -EINVAL;



	if (info->attrs[NL80211_ATTR_MAC])

		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);



	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);

	if (err)

		return err;



	if (!drv->ops->del_key) {

		err = -EOPNOTSUPP;

		goto out;

	}



	rtnl_lock();

	err = drv->ops->del_key(&drv->wiphy, dev, key_idx, mac_addr);

	rtnl_unlock();



 out:

	cfg80211_put_dev(drv);

	dev_put(dev);

	return err;

}



static struct genl_ops nl80211_ops[] = {

	{

		.cmd = NL80211_CMD_GET_WIPHY,
@@ -374,6 +639,30 @@ static struct genl_ops nl80211_ops[] = { 
		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

	},

	{

		.cmd = NL80211_CMD_GET_KEY,

		.doit = nl80211_get_key,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

	},

	{

		.cmd = NL80211_CMD_SET_KEY,

		.doit = nl80211_set_key,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

	},

	{

		.cmd = NL80211_CMD_NEW_KEY,

		.doit = nl80211_new_key,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

	},

	{

		.cmd = NL80211_CMD_DEL_KEY,

		.doit = nl80211_del_key,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

	},

};



/* multicast groups */