From: Xiao Liang <shaw.leon@xxxxxxxxx>
Date: Mon, 10 Feb 2025 21:29:56 +0800
> When link_net is set, use it as link netns instead of dev_net(). This
> prepares for rtnetlink core to create device in target netns directly,
> in which case the two namespaces may be different.
>
> Convert common ip_tunnel_newlink() to accept an extra link netns
> argument. Don't overwrite ip_tunnel.net in ip_tunnel_init().
Why... ? see a comment below.
[...]
> diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
> index 1fe9b13d351c..26d15f907551 100644
> --- a/net/ipv4/ip_gre.c
> +++ b/net/ipv4/ip_gre.c
> @@ -1413,7 +1413,8 @@ static int ipgre_newlink(struct net_device *dev,
> err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
> if (err < 0)
> return err;
> - return ip_tunnel_newlink(dev, tb, &p, fwmark);
> + return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
This is duplicate at all call sites, let's move it into
ip_tunnel_newlink() by passing params.
> + fwmark);
> }
>
> static int erspan_newlink(struct net_device *dev,
>
>
> diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
> index 09b73acf037a..618a50d5c0c2 100644
> --- a/net/ipv4/ip_tunnel.c
> +++ b/net/ipv4/ip_tunnel.c
> @@ -1213,11 +1213,11 @@ void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id,
> }
> EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets);
>
> -int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
> - struct ip_tunnel_parm_kern *p, __u32 fwmark)
> +int ip_tunnel_newlink(struct net *net, struct net_device *dev,
> + struct nlattr *tb[], struct ip_tunnel_parm_kern *p,
> + __u32 fwmark)
> {
> struct ip_tunnel *nt;
> - struct net *net = dev_net(dev);
> struct ip_tunnel_net *itn;
> int mtu;
> int err;
> @@ -1326,7 +1326,9 @@ int ip_tunnel_init(struct net_device *dev)
> }
>
> tunnel->dev = dev;
> - tunnel->net = dev_net(dev);
> + if (!tunnel->net)
> + tunnel->net = dev_net(dev);
Isn't tunnel->net always non-NULL ?
ip_tunnel_newlink
-> netdev_priv(dev)->net = net
-> register_netdevice(dev)
-> dev->netdev_ops->ndo_init(dev)
-> ip_tunnel_init(dev)
-> netdev_priv(dev)->net = dev_net(dev)
