cfg80211: rework key operation

This reworks the key operation in cfg80211, and now only
allows, from userspace, configuring keys (via nl80211)
after the connection has been established (in managed
mode), the IBSS been joined (in IBSS mode), at any time
(in AP[_VLAN] modes) or never for all the other modes.

In order to do shared key authentication correctly, it
is now possible to give a WEP key to the AUTH command.
To configure static WEP keys, these are given to the
CONNECT or IBSS_JOIN command directly, for a userspace
SME it is assumed it will configure it properly after
the connection has been established.

Since mac80211 used to check the default key in IBSS
mode to see whether or not the network is protected,
it needs an update in that area, as well as an update
to make use of the WEP key passed to auth() for shared
key authentication.

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

1 files changed, 151 insertions, 19 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 50cf5931629..45c5f9c8e51 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -138,8 +138,7 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
 /* policy for the attributes */
 static struct nla_policy
 nl80211_key_policy[NL80211_KEY_MAX + 1] __read_mostly = {
-        [NL80211_KEY_DATA] = { .type = NLA_BINARY,
-                                    .len = WLAN_MAX_KEY_LEN },
+        [NL80211_KEY_DATA] = { .type = NLA_BINARY, .len = WLAN_MAX_KEY_LEN },
         [NL80211_KEY_IDX] = { .type = NLA_U8 },
         [NL80211_KEY_CIPHER] = { .type = NLA_U32 },
         [NL80211_KEY_SEQ] = { .type = NLA_BINARY, .len = 8 },
@@ -305,6 +304,83 @@ static int nl80211_parse_key(struct genl_info *info, struct key_parse *k)
         return 0;
 }
 
+static struct cfg80211_cached_keys *
+nl80211_parse_connkeys(struct cfg80211_registered_device *rdev,
+                       struct nlattr *keys)
+{
+        struct key_parse parse;
+        struct nlattr *key;
+        struct cfg80211_cached_keys *result;
+        int rem, err, def = 0;
+
+        result = kzalloc(sizeof(*result), GFP_KERNEL);
+        if (!result)
+                return ERR_PTR(-ENOMEM);
+
+        result->def = -1;
+        result->defmgmt = -1;
+
+        nla_for_each_nested(key, keys, rem) {
+                memset(&parse, 0, sizeof(parse));
+                parse.idx = -1;
+
+                err = nl80211_parse_key_new(key, &parse);
+                if (err)
+                        goto error;
+                err = -EINVAL;
+                if (!parse.p.key)
+                        goto error;
+                if (parse.idx < 0 || parse.idx > 4)
+                        goto error;
+                if (parse.def) {
+                        if (def)
+                                goto error;
+                        def = 1;
+                        result->def = parse.idx;
+                } else if (parse.defmgmt)
+                        goto error;
+                err = cfg80211_validate_key_settings(rdev, &parse.p,
+                                                     parse.idx, NULL);
+                if (err)
+                        goto error;
+                result->params[parse.idx].cipher = parse.p.cipher;
+                result->params[parse.idx].key_len = parse.p.key_len;
+                result->params[parse.idx].key = result->data[parse.idx];
+                memcpy(result->data[parse.idx], parse.p.key, parse.p.key_len);
+        }
+
+        return result;
+ error:
+        kfree(result);
+        return ERR_PTR(err);
+}
+
+static int nl80211_key_allowed(struct wireless_dev *wdev)
+{
+        ASSERT_WDEV_LOCK(wdev);
+
+        if (!netif_running(wdev->netdev))
+                return -ENETDOWN;
+
+        switch (wdev->iftype) {
+        case NL80211_IFTYPE_AP:
+        case NL80211_IFTYPE_AP_VLAN:
+                break;
+        case NL80211_IFTYPE_ADHOC:
+                if (!wdev->current_bss)
+                        return -ENOLINK;
+                break;
+        case NL80211_IFTYPE_STATION:
+                if (wdev->sme_state != CFG80211_SME_CONNECTED)
+                        return -ENOLINK;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
 static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
                               struct cfg80211_registered_device *dev)
 {
@@ -1212,7 +1288,11 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
                 goto out;
         }
 
-        err = func(&rdev->wiphy, dev, key.idx);
+        wdev_lock(dev->ieee80211_ptr);
+        err = nl80211_key_allowed(dev->ieee80211_ptr);
+        if (!err)
+                err = func(&rdev->wiphy, dev, key.idx);
+
 #ifdef CONFIG_WIRELESS_EXT
         if (!err) {
                 if (func == rdev->ops->set_default_key)
@@ -1221,6 +1301,7 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
                         dev->ieee80211_ptr->wext.default_mgmt_key = key.idx;
         }
 #endif
+        wdev_unlock(dev->ieee80211_ptr);
 
  out:
         cfg80211_unlock_rdev(rdev);
@@ -1235,7 +1316,7 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
 static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev;
-        int err, i;
+        int err;
         struct net_device *dev;
         struct key_parse key;
         u8 *mac_addr = NULL;
@@ -1250,29 +1331,28 @@ 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 (cfg80211_validate_key_settings(&key.p, key.idx, mac_addr))
-                return -EINVAL;
-
         rtnl_lock();
 
         err = get_rdev_dev_by_info_ifindex(info->attrs, &rdev, &dev);
         if (err)
                 goto unlock_rtnl;
 
-        for (i = 0; i < rdev->wiphy.n_cipher_suites; i++)
-                if (key.p.cipher == rdev->wiphy.cipher_suites[i])
-                        break;
-        if (i == rdev->wiphy.n_cipher_suites) {
-                err = -EINVAL;
+        if (!rdev->ops->add_key) {
+                err = -EOPNOTSUPP;
                 goto out;
         }
 
-        if (!rdev->ops->add_key) {
-                err = -EOPNOTSUPP;
+        if (cfg80211_validate_key_settings(rdev, &key.p, key.idx, mac_addr)) {
+                err = -EINVAL;
                 goto out;
         }
 
-        err = rdev->ops->add_key(&rdev->wiphy, dev, key.idx, mac_addr, &key.p);
+        wdev_lock(dev->ieee80211_ptr);
+        err = nl80211_key_allowed(dev->ieee80211_ptr);
+        if (!err)
+                err = rdev->ops->add_key(&rdev->wiphy, dev, key.idx,
+                                         mac_addr, &key.p);
+        wdev_unlock(dev->ieee80211_ptr);
 
  out:
         cfg80211_unlock_rdev(rdev);
@@ -1309,7 +1389,10 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
                 goto out;
         }
 
-        err = rdev->ops->del_key(&rdev->wiphy, dev, key.idx, mac_addr);
+        wdev_lock(dev->ieee80211_ptr);
+        err = nl80211_key_allowed(dev->ieee80211_ptr);
+        if (!err)
+                err = rdev->ops->del_key(&rdev->wiphy, dev, key.idx, mac_addr);
 
 #ifdef CONFIG_WIRELESS_EXT
         if (!err) {
@@ -1319,6 +1402,7 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
                         dev->ieee80211_ptr->wext.default_mgmt_key = -1;
         }
 #endif
+        wdev_unlock(dev->ieee80211_ptr);
 
  out:
         cfg80211_unlock_rdev(rdev);
@@ -3159,6 +3243,7 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
         const u8 *bssid, *ssid, *ie = NULL;
         int err, ssid_len, ie_len = 0;
         enum nl80211_auth_type auth_type;
+        struct key_parse key;
 
         if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
                 return -EINVAL;
@@ -3175,6 +3260,25 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
         if (!info->attrs[NL80211_ATTR_WIPHY_FREQ])
                 return -EINVAL;
 
+        err = nl80211_parse_key(info, &key);
+        if (err)
+                return err;
+
+        if (key.idx >= 0) {
+                if (!key.p.key || !key.p.key_len)
+                        return -EINVAL;
+                if ((key.p.cipher != WLAN_CIPHER_SUITE_WEP40 ||
+                     key.p.key_len != WLAN_KEY_LEN_WEP40) &&
+                    (key.p.cipher != WLAN_CIPHER_SUITE_WEP104 ||
+                     key.p.key_len != WLAN_KEY_LEN_WEP104))
+                        return -EINVAL;
+                if (key.idx > 4)
+                        return -EINVAL;
+        } else {
+                key.p.key_len = 0;
+                key.p.key = NULL;
+        }
+
         rtnl_lock();
 
         err = get_rdev_dev_by_info_ifindex(info->attrs, &rdev, &dev);
@@ -3219,7 +3323,8 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
         }
 
         err = cfg80211_mlme_auth(rdev, dev, chan, auth_type, bssid,
-                                 ssid, ssid_len, ie, ie_len);
+                                 ssid, ssid_len, ie, ie_len,
+                                 key.p.key, key.p.key_len, key.idx);
 
 out:
         cfg80211_unlock_rdev(rdev);
@@ -3506,6 +3611,7 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
         struct net_device *dev;
         struct cfg80211_ibss_params ibss;
         struct wiphy *wiphy;
+        struct cfg80211_cached_keys *connkeys = NULL;
         int err;
 
         memset(&ibss, 0, sizeof(ibss));
@@ -3570,13 +3676,26 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
         }
 
         ibss.channel_fixed = !!info->attrs[NL80211_ATTR_FREQ_FIXED];
+        ibss.privacy = !!info->attrs[NL80211_ATTR_PRIVACY];
+
+        if (ibss.privacy && info->attrs[NL80211_ATTR_KEYS]) {
+                connkeys = nl80211_parse_connkeys(rdev,
+                                        info->attrs[NL80211_ATTR_KEYS]);
+                if (IS_ERR(connkeys)) {
+                        err = PTR_ERR(connkeys);
+                        connkeys = NULL;
+                        goto out;
+                }
+        }
 
-        err = cfg80211_join_ibss(rdev, dev, &ibss);
+        err = cfg80211_join_ibss(rdev, dev, &ibss, connkeys);
 
 out:
         cfg80211_unlock_rdev(rdev);
         dev_put(dev);
 unlock_rtnl:
+        if (err)
+                kfree(connkeys);
         rtnl_unlock();
         return err;
 }
@@ -3746,6 +3865,7 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
         struct net_device *dev;
         struct cfg80211_connect_params connect;
         struct wiphy *wiphy;
+        struct cfg80211_cached_keys *connkeys = NULL;
         int err;
 
         memset(&connect, 0, sizeof(connect));
@@ -3810,12 +3930,24 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info)
                 }
         }
 
-        err = cfg80211_connect(rdev, dev, &connect);
+        if (connect.privacy && info->attrs[NL80211_ATTR_KEYS]) {
+                connkeys = nl80211_parse_connkeys(rdev,
+                                        info->attrs[NL80211_ATTR_KEYS]);
+                if (IS_ERR(connkeys)) {
+                        err = PTR_ERR(connkeys);
+                        connkeys = NULL;
+                        goto out;
+                }
+        }
+
+        err = cfg80211_connect(rdev, dev, &connect, connkeys);
 
 out:
         cfg80211_unlock_rdev(rdev);
         dev_put(dev);
 unlock_rtnl:
+        if (err)
+                kfree(connkeys);
         rtnl_unlock();
         return err;
 }