[PATCH net-next v3 05/24] ovpn: implement interface creation/destruction via netlink

Antonio Quartulli
2024-05-06T01:15:36Z

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 | 55 ++++++++++++++++++++++++++++++++++++--
2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ovpn/main.h b/drivers/net/ovpn/main.h
index 21d6bfb27d67..12b8d7e4a0fe 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"
+
/**
* ovpn_iface_create - create and initialize a new 'ovpn' netdevice
* @name: the name of the new device
diff --git a/drivers/net/ovpn/netlink.c b/drivers/net/ovpn/netlink.c
index c0a9f58e0e87..66f5c6fbe8e4 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>
@@ -78,12 +79,62 @@ 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 -ENOTSUPP;
+ 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)) {
+ pr_err("ovpn: error while creating interface %s: %ld\n", ifname,
+ PTR_ERR(dev));
+ return PTR_ERR(dev);
+ }
+
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, &ovpn_nl_family,
+ 0, OVPN_CMD_NEW_IFACE);
+ if (!hdr) {
+ netdev_err(dev, "%s: cannot create message header\n", __func__);
+ return -EMSGSIZE;
+ }
+
+ if (nla_put(msg, OVPN_A_IFNAME, strlen(dev->name) + 1, dev->name)) {
+ netdev_err(dev, "%s: cannot add ifname to reply\n", __func__);
+ 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 -ENOTSUPP;
+ struct ovpn_struct *ovpn = info->user_ptr[0];
+
+ rtnl_lock();
+ ovpn_iface_destruct(ovpn);
+ dev_put(ovpn->dev);
+ rtnl_unlock();
+
+ synchronize_net();
+
+ return 0;
}

int ovpn_nl_set_peer_doit(struct sk_buff *skb, struct genl_info *info)
--
2.43.2