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

2 files changed, 292 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index febc33bc9c09..cfc5fc5f9e75 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -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);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 48b0d453e4e1..090936388528 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -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 */