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, 255 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c034c2418cb3..9e1318d1d4bb 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -111,6 +111,11 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
                               .len = IEEE80211_MAX_DATA_LEN },
         [NL80211_ATTR_SCAN_FREQUENCIES] = { .type = NLA_NESTED },
         [NL80211_ATTR_SCAN_SSIDS] = { .type = NLA_NESTED },
+
+        [NL80211_ATTR_SSID] = { .type = NLA_BINARY,
+                                .len = IEEE80211_MAX_SSID_LEN },
+        [NL80211_ATTR_AUTH_TYPE] = { .type = NLA_U32 },
+        [NL80211_ATTR_REASON_CODE] = { .type = NLA_U16 },
 };
 
 /* message building helper */
@@ -265,6 +270,10 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
         CMD(set_mesh_params, SET_MESH_PARAMS);
         CMD(change_bss, SET_BSS);
         CMD(set_mgmt_extra_ie, SET_MGMT_EXTRA_IE);
+        CMD(auth, AUTHENTICATE);
+        CMD(assoc, ASSOCIATE);
+        CMD(deauth, DEAUTHENTICATE);
+        CMD(disassoc, DISASSOCIATE);
 
 #undef CMD
         nla_nest_end(msg, nl_cmds);
@@ -2646,6 +2655,228 @@ static int nl80211_dump_scan(struct sk_buff *skb,
         return err;
 }
 
+static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg80211_registered_device *drv;
+        struct net_device *dev;
+        struct cfg80211_auth_request req;
+        struct wiphy *wiphy;
+        int err;
+
+        rtnl_lock();
+
+        err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
+        if (err)
+                goto unlock_rtnl;
+
+        if (!drv->ops->auth) {
+                err = -EOPNOTSUPP;
+                goto out;
+        }
+
+        if (!info->attrs[NL80211_ATTR_MAC]) {
+                err = -EINVAL;
+                goto out;
+        }
+
+        wiphy = &drv->wiphy;
+        memset(&req, 0, sizeof(req));
+
+        req.peer_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+        if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
+                req.chan = ieee80211_get_channel(
+                        wiphy,
+                        nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+                if (!req.chan) {
+                        err = -EINVAL;
+                        goto out;
+                }
+        }
+
+        if (info->attrs[NL80211_ATTR_SSID]) {
+                req.ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
+                req.ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);
+        }
+
+        if (info->attrs[NL80211_ATTR_IE]) {
+                req.ie = nla_data(info->attrs[NL80211_ATTR_IE]);
+                req.ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
+        }
+
+        if (info->attrs[NL80211_ATTR_AUTH_TYPE]) {
+                req.auth_type =
+                        nla_get_u32(info->attrs[NL80211_ATTR_AUTH_TYPE]);
+        }
+
+        err = drv->ops->auth(&drv->wiphy, dev, &req);
+
+out:
+        cfg80211_put_dev(drv);
+        dev_put(dev);
+unlock_rtnl:
+        rtnl_unlock();
+        return err;
+}
+
+static int nl80211_associate(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg80211_registered_device *drv;
+        struct net_device *dev;
+        struct cfg80211_assoc_request req;
+        struct wiphy *wiphy;
+        int err;
+
+        rtnl_lock();
+
+        err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
+        if (err)
+                goto unlock_rtnl;
+
+        if (!drv->ops->assoc) {
+                err = -EOPNOTSUPP;
+                goto out;
+        }
+
+        if (!info->attrs[NL80211_ATTR_MAC] ||
+            !info->attrs[NL80211_ATTR_SSID]) {
+                err = -EINVAL;
+                goto out;
+        }
+
+        wiphy = &drv->wiphy;
+        memset(&req, 0, sizeof(req));
+
+        req.peer_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+        if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
+                req.chan = ieee80211_get_channel(
+                        wiphy,
+                        nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]));
+                if (!req.chan) {
+                        err = -EINVAL;
+                        goto out;
+                }
+        }
+
+        if (nla_len(info->attrs[NL80211_ATTR_SSID]) > IEEE80211_MAX_SSID_LEN) {
+                err = -EINVAL;
+                goto out;
+        }
+        req.ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
+        req.ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);
+
+        if (info->attrs[NL80211_ATTR_IE]) {
+                req.ie = nla_data(info->attrs[NL80211_ATTR_IE]);
+                req.ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
+        }
+
+        err = drv->ops->assoc(&drv->wiphy, dev, &req);
+
+out:
+        cfg80211_put_dev(drv);
+        dev_put(dev);
+unlock_rtnl:
+        rtnl_unlock();
+        return err;
+}
+
+static int nl80211_deauthenticate(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg80211_registered_device *drv;
+        struct net_device *dev;
+        struct cfg80211_deauth_request req;
+        struct wiphy *wiphy;
+        int err;
+
+        rtnl_lock();
+
+        err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
+        if (err)
+                goto unlock_rtnl;
+
+        if (!drv->ops->deauth) {
+                err = -EOPNOTSUPP;
+                goto out;
+        }
+
+        if (!info->attrs[NL80211_ATTR_MAC]) {
+                err = -EINVAL;
+                goto out;
+        }
+
+        wiphy = &drv->wiphy;
+        memset(&req, 0, sizeof(req));
+
+        req.peer_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+        if (info->attrs[NL80211_ATTR_REASON_CODE])
+                req.reason_code =
+                        nla_get_u16(info->attrs[NL80211_ATTR_REASON_CODE]);
+
+        if (info->attrs[NL80211_ATTR_IE]) {
+                req.ie = nla_data(info->attrs[NL80211_ATTR_IE]);
+                req.ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
+        }
+
+        err = drv->ops->deauth(&drv->wiphy, dev, &req);
+
+out:
+        cfg80211_put_dev(drv);
+        dev_put(dev);
+unlock_rtnl:
+        rtnl_unlock();
+        return err;
+}
+
+static int nl80211_disassociate(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg80211_registered_device *drv;
+        struct net_device *dev;
+        struct cfg80211_disassoc_request req;
+        struct wiphy *wiphy;
+        int err;
+
+        rtnl_lock();
+
+        err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
+        if (err)
+                goto unlock_rtnl;
+
+        if (!drv->ops->disassoc) {
+                err = -EOPNOTSUPP;
+                goto out;
+        }
+
+        if (!info->attrs[NL80211_ATTR_MAC]) {
+                err = -EINVAL;
+                goto out;
+        }
+
+        wiphy = &drv->wiphy;
+        memset(&req, 0, sizeof(req));
+
+        req.peer_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+        if (info->attrs[NL80211_ATTR_REASON_CODE])
+                req.reason_code =
+                        nla_get_u16(info->attrs[NL80211_ATTR_REASON_CODE]);
+
+        if (info->attrs[NL80211_ATTR_IE]) {
+                req.ie = nla_data(info->attrs[NL80211_ATTR_IE]);
+                req.ie_len = nla_len(info->attrs[NL80211_ATTR_IE]);
+        }
+
+        err = drv->ops->disassoc(&drv->wiphy, dev, &req);
+
+out:
+        cfg80211_put_dev(drv);
+        dev_put(dev);
+unlock_rtnl:
+        rtnl_unlock();
+        return err;
+}
+
 static struct genl_ops nl80211_ops[] = {
         {
                 .cmd = NL80211_CMD_GET_WIPHY,
@@ -2829,6 +3060,30 @@ static struct genl_ops nl80211_ops[] = {
                 .policy = nl80211_policy,
                 .dumpit = nl80211_dump_scan,
         },
+        {
+                .cmd = NL80211_CMD_AUTHENTICATE,
+                .doit = nl80211_authenticate,
+                .policy = nl80211_policy,
+                .flags = GENL_ADMIN_PERM,
+        },
+        {
+                .cmd = NL80211_CMD_ASSOCIATE,
+                .doit = nl80211_associate,
+                .policy = nl80211_policy,
+                .flags = GENL_ADMIN_PERM,
+        },
+        {
+                .cmd = NL80211_CMD_DEAUTHENTICATE,
+                .doit = nl80211_deauthenticate,
+                .policy = nl80211_policy,
+                .flags = GENL_ADMIN_PERM,
+        },
+        {
+                .cmd = NL80211_CMD_DISASSOCIATE,
+                .doit = nl80211_disassociate,
+                .policy = nl80211_policy,
+                .flags = GENL_ADMIN_PERM,
+        },
 };
 static struct genl_multicast_group nl80211_mlme_mcgrp = {
         .name = "mlme",