[PATCH net-next v4 06/25] ovpn: implement interface creation/destruction via netlink

[Antonio Quartulli <antonio@openvpn.net>]

Allow userspace to create and destroy an interface using netlink
commands.

Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
---
 drivers/net/ovpn/main.h    |  2 ++
 drivers/net/ovpn/netlink.c | 53 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ovpn/main.h b/drivers/net/ovpn/main.h
index 4dfcba9deb59..c664d9c65573 100644
--- a/drivers/net/ovpn/main.h
+++ b/drivers/net/ovpn/main.h
@@ -10,6 +10,8 @@
 #ifndef _NET_OVPN_MAIN_H_
 #define _NET_OVPN_MAIN_H_
 
+#define OVPN_DEFAULT_IFNAME "ovpn%d"
+
 struct net_device *ovpn_iface_create(const char *name, enum ovpn_mode mode,
 				     struct net *net);
 void ovpn_iface_destruct(struct ovpn_struct *ovpn);
diff --git a/drivers/net/ovpn/netlink.c b/drivers/net/ovpn/netlink.c
index 5f2c1eacc463..28f2216214b0 100644
--- a/drivers/net/ovpn/netlink.c
+++ b/drivers/net/ovpn/netlink.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
 #include <net/genetlink.h>
 
 #include <uapi/linux/ovpn.h>
@@ -84,12 +85,60 @@ void ovpn_nl_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
 
 int ovpn_nl_new_iface_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	return -EOPNOTSUPP;
+	const char *ifname = OVPN_DEFAULT_IFNAME;
+	enum ovpn_mode mode = OVPN_MODE_P2P;
+	struct net_device *dev;
+	struct sk_buff *msg;
+	void *hdr;
+
+	if (info->attrs[OVPN_A_IFNAME])
+		ifname = nla_data(info->attrs[OVPN_A_IFNAME]);
+
+	if (info->attrs[OVPN_A_MODE]) {
+		mode = nla_get_u32(info->attrs[OVPN_A_MODE]);
+		pr_debug("ovpn: setting device (%s) mode: %u\n", ifname, mode);
+	}
+
+	dev = ovpn_iface_create(ifname, mode, genl_info_net(info));
+	if (IS_ERR(dev)) {
+		NL_SET_ERR_MSG_FMT_MOD(info->extack,
+				       "error while creating interface: %ld",
+				       PTR_ERR(dev));
+		return PTR_ERR(dev);
+	}
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_iput(msg, info);
+	if (!hdr) {
+		nlmsg_free(msg);
+		return -ENOBUFS;
+	}
+
+	if (nla_put_string(msg, OVPN_A_IFNAME, dev->name)) {
+		genlmsg_cancel(msg, hdr);
+		nlmsg_free(msg);
+		return -EMSGSIZE;
+	}
+
+	genlmsg_end(msg, hdr);
+
+	return genlmsg_reply(msg, info);
 }
 
 int ovpn_nl_del_iface_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	return -EOPNOTSUPP;
+	struct ovpn_struct *ovpn = info->user_ptr[0];
+
+	rtnl_lock();
+	ovpn_iface_destruct(ovpn);
+	unregister_netdevice(ovpn->dev);
+	netdev_put(ovpn->dev, NULL);
+	rtnl_unlock();
+
+	return 0;
 }
 
 int ovpn_nl_set_peer_doit(struct sk_buff *skb, struct genl_info *info)
-- 
2.44.2