nl80211: Add MLME primitives to support external SME

This patch adds new nl80211 commands to allow user space to request
authentication and association (and also deauthentication and
disassociation). The commands are structured to allow separate
authentication and association steps, i.e., the interface between
kernel and user space is similar to the MLME SAP interface in IEEE
802.11 standard and an user space application takes the role of the
SME.

The patch introduces MLME-AUTHENTICATE.request,
MLME-{,RE}ASSOCIATE.request, MLME-DEAUTHENTICATE.request, and
MLME-DISASSOCIATE.request primitives. The authentication and
association commands request the actual operations in two steps
(assuming the driver supports this; if not, separate authentication
step is skipped; this could end up being a separate "connect"
command).

The initial implementation for mac80211 uses the current
net/mac80211/mlme.c for actual sending and processing of management
frames and the new nl80211 commands will just stop the current state
machine from moving automatically from authentication to association.
Future cleanup may move more of the MLME operations into cfg80211.

The goal of this design is to provide more control of authentication and
association process to user space without having to move the full MLME
implementation. This should be enough to allow IEEE 802.11r FT protocol
and 802.11s SAE authentication to be implemented. Obviously, this will
also bring the extra benefit of not having to use WEXT for association
requests with mac80211. An example implementation of a user space SME
using the new nl80211 commands is available for wpa_supplicant.

This patch is enough to get IEEE 802.11r FT protocol working with
over-the-air mechanism (over-the-DS will need additional MLME
primitives for handling the FT Action frames).

Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 140 insertions, 0 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 58693e52d45..223e536e842 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1300,6 +1300,142 @@ static int ieee80211_scan(struct wiphy *wiphy,
 	return ieee80211_request_scan(sdata, req);
 }
 
+static int ieee80211_auth(struct wiphy *wiphy, struct net_device *dev,
+			  struct cfg80211_auth_request *req)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	if (sdata->vif.type != NL80211_IFTYPE_STATION)
+		return -EOPNOTSUPP;
+
+	switch (req->auth_type) {
+	case NL80211_AUTHTYPE_OPEN_SYSTEM:
+		sdata->u.mgd.auth_algs = IEEE80211_AUTH_ALG_OPEN;
+		break;
+	case NL80211_AUTHTYPE_SHARED_KEY:
+		sdata->u.mgd.auth_algs = IEEE80211_AUTH_ALG_SHARED_KEY;
+		break;
+	case NL80211_AUTHTYPE_FT:
+		sdata->u.mgd.auth_algs = IEEE80211_AUTH_ALG_FT;
+		break;
+	case NL80211_AUTHTYPE_NETWORK_EAP:
+		sdata->u.mgd.auth_algs = IEEE80211_AUTH_ALG_LEAP;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	memcpy(sdata->u.mgd.bssid, req->peer_addr, ETH_ALEN);
+	sdata->u.mgd.flags &= ~IEEE80211_STA_AUTO_BSSID_SEL;
+	sdata->u.mgd.flags |= IEEE80211_STA_BSSID_SET;
+
+	/* TODO: req->chan */
+	sdata->u.mgd.flags |= IEEE80211_STA_AUTO_CHANNEL_SEL;
+
+	if (req->ssid) {
+		sdata->u.mgd.flags |= IEEE80211_STA_SSID_SET;
+		memcpy(sdata->u.mgd.ssid, req->ssid, req->ssid_len);
+		sdata->u.mgd.ssid_len = req->ssid_len;
+		sdata->u.mgd.flags &= ~IEEE80211_STA_AUTO_SSID_SEL;
+	}
+
+	kfree(sdata->u.mgd.sme_auth_ie);
+	sdata->u.mgd.sme_auth_ie = NULL;
+	sdata->u.mgd.sme_auth_ie_len = 0;
+	if (req->ie) {
+		sdata->u.mgd.sme_auth_ie = kmalloc(req->ie_len, GFP_KERNEL);
+		if (sdata->u.mgd.sme_auth_ie == NULL)
+			return -ENOMEM;
+		memcpy(sdata->u.mgd.sme_auth_ie, req->ie, req->ie_len);
+		sdata->u.mgd.sme_auth_ie_len = req->ie_len;
+	}
+
+	sdata->u.mgd.flags |= IEEE80211_STA_EXT_SME;
+	sdata->u.mgd.state = IEEE80211_STA_MLME_DIRECT_PROBE;
+	ieee80211_sta_req_auth(sdata);
+	return 0;
+}
+
+static int ieee80211_assoc(struct wiphy *wiphy, struct net_device *dev,
+			   struct cfg80211_assoc_request *req)
+{
+	struct ieee80211_sub_if_data *sdata;
+	int ret;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	if (sdata->vif.type != NL80211_IFTYPE_STATION)
+		return -EOPNOTSUPP;
+
+	if (memcmp(sdata->u.mgd.bssid, req->peer_addr, ETH_ALEN) != 0 ||
+	    !(sdata->u.mgd.flags & IEEE80211_STA_AUTHENTICATED))
+		return -ENOLINK; /* not authenticated */
+
+	sdata->u.mgd.flags &= ~IEEE80211_STA_AUTO_BSSID_SEL;
+	sdata->u.mgd.flags |= IEEE80211_STA_BSSID_SET;
+
+	/* TODO: req->chan */
+	sdata->u.mgd.flags |= IEEE80211_STA_AUTO_CHANNEL_SEL;
+
+	if (req->ssid) {
+		sdata->u.mgd.flags |= IEEE80211_STA_SSID_SET;
+		memcpy(sdata->u.mgd.ssid, req->ssid, req->ssid_len);
+		sdata->u.mgd.ssid_len = req->ssid_len;
+		sdata->u.mgd.flags &= ~IEEE80211_STA_AUTO_SSID_SEL;
+	} else
+		sdata->u.mgd.flags |= IEEE80211_STA_AUTO_SSID_SEL;
+
+	ret = ieee80211_sta_set_extra_ie(sdata, req->ie, req->ie_len);
+	if (ret)
+		return ret;
+
+	sdata->u.mgd.flags |= IEEE80211_STA_EXT_SME;
+	sdata->u.mgd.state = IEEE80211_STA_MLME_ASSOCIATE;
+	ieee80211_sta_req_auth(sdata);
+	return 0;
+}
+
+static int ieee80211_deauth(struct wiphy *wiphy, struct net_device *dev,
+			    struct cfg80211_deauth_request *req)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	if (sdata->vif.type != NL80211_IFTYPE_STATION)
+		return -EOPNOTSUPP;
+
+	/* TODO: req->ie */
+	return ieee80211_sta_deauthenticate(sdata, req->reason_code);
+}
+
+static int ieee80211_disassoc(struct wiphy *wiphy, struct net_device *dev,
+			      struct cfg80211_disassoc_request *req)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+	if (sdata->vif.type != NL80211_IFTYPE_STATION)
+		return -EOPNOTSUPP;
+
+	/* TODO: req->ie */
+	return ieee80211_sta_disassociate(sdata, req->reason_code);
+}
+
 struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -1333,4 +1469,8 @@ struct cfg80211_ops mac80211_config_ops = {
 	.suspend = ieee80211_suspend,
 	.resume = ieee80211_resume,
 	.scan = ieee80211_scan,
+	.auth = ieee80211_auth,
+	.assoc = ieee80211_assoc,
+	.deauth = ieee80211_deauth,
+	.disassoc = ieee80211_disassoc,
 };