Subject: [PATCH net-next v7 05/11] net: ip_tunnel: Use link netns in newlink() of rtnl_link_ops

From: Xiao Liang <[email-masked]>
Date: Sat, 4 Jan 2025 20:57:26 +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().

Signed-off-by: Xiao Liang <[email-masked]>
---
 include/net/ip_tunnels.h |  5 +++--
 net/ipv4/ip_gre.c        |  8 +++++---
 net/ipv4/ip_tunnel.c     | 10 ++++++----
 net/ipv4/ip_vti.c        |  3 ++-
 net/ipv4/ipip.c          |  3 ++-
 5 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 1aa31bdb2b31..ae1f2dda4533 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -406,8 +406,9 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
 		  bool log_ecn_error);
 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
 			 struct ip_tunnel_parm_kern *p, __u32 fwmark);
-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);
 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id);
 
 bool ip_tunnel_netlink_encap_parms(struct nlattr *data[],
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 71eb651e2b44..d1b712b775b6 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1408,7 +1408,8 @@ static int ipgre_newlink(struct rtnl_newlink_params *params)
 	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,
+				 fwmark);
 }
 
 static int erspan_newlink(struct rtnl_newlink_params *params)
@@ -1427,7 +1428,8 @@ static int erspan_newlink(struct rtnl_newlink_params *params)
 	err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
 	if (err)
 		return err;
-	return ip_tunnel_newlink(dev, tb, &p, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
 }
 
 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
@@ -1701,7 +1703,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	struct ip_tunnel *t;
 	int err;
 	struct rtnl_newlink_params params = {
-		.net = net,
+		.src_net = net,
 		.tb = tb,
 	};
 
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 25505f9b724c..952d2241c9b1 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);
+
 	strscpy(tunnel->parms.name, dev->name);
 	iph->version		= 4;
 	iph->ihl		= 5;
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 12ccbf34fb6c..98752b4d28ad 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -584,7 +584,8 @@ static int vti_newlink(struct rtnl_newlink_params *params)
 	__u32 fwmark = 0;
 
 	vti_netlink_parms(data, &parms, &fwmark);
-	return ip_tunnel_newlink(dev, tb, &parms, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb,
+				 &parms, fwmark);
 }
 
 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 3a737ea3c2e5..c65c8b0e838f 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -456,7 +456,8 @@ static int ipip_newlink(struct rtnl_newlink_params *params)
 	}
 
 	ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
-	return ip_tunnel_newlink(dev, tb, &p, fwmark);
+	return ip_tunnel_newlink(params->link_net ? : dev_net(dev), dev, tb, &p,
+				 fwmark);
 }
 
 static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
-- 
2.47.1