[PATCH net-next v4 0/5] net: Improve netns handling in RTNL and ip_tunnel

[PATCH net-next v4 0/5] net: Improve netns handling in RTNL and ip_tunnel

[Xiao Liang]

This patch series includes some netns-related improvements and fixes for
RTNL and ip_tunnel, to make link creation more intuitive:

 - Creating link in another net namespace doesn't conflict with link names
   in current one.
 - Refector rtnetlink link creation. Create link in target namespace
   directly. Pass both source and link netns to drivers via newlink()
   callback.

So that

  # ip link add netns ns1 link-netns ns2 tun0 type gre ...

will create tun0 in ns1, rather than create it in ns2 and move to ns1.
And don't conflict with another interface named "tun0" in current netns.

---

v4:
 - Pack newlink() parameters to a single struct.
 - Use ynl async_msg_queue.empty() in selftest.

v3:
 link: https://lore.kernel.org/all/20241113125715.150201-1-shaw.leon@gmail.com/
 - Drop "netns_atomic" flag and module parameter. Add netns parameter to
   newlink() instead, and convert drivers accordingly.
 - Move python NetNSEnter helper to net selftest lib.

v2:
 link: https://lore.kernel.org/all/20241107133004.7469-1-shaw.leon@gmail.com/
 - Check NLM_F_EXCL to ensure only link creation is affected.
 - Add self tests for link name/ifindex conflict and notifications
   in different netns.
 - Changes in dummy driver and ynl in order to add the test case.

v1:
 link: https://lore.kernel.org/all/20241023023146.372653-1-shaw.leon@gmail.com/


Xiao Liang (5):
  net: ip_tunnel: Build flow in underlay net namespace
  rtnetlink: Lookup device in target netns when creating link
  rtnetlink: Decouple net namespaces in rtnl_newlink_create()
  selftests: net: Add python context manager for netns entering
  selftests: net: Add two test cases for link netns

 drivers/infiniband/ulp/ipoib/ipoib_netlink.c  | 11 ++++--
 drivers/net/amt.c                             | 13 ++++---
 drivers/net/bareudp.c                         | 11 ++++--
 drivers/net/bonding/bond_netlink.c            |  8 ++--
 drivers/net/can/dev/netlink.c                 |  4 +-
 drivers/net/can/vxcan.c                       | 11 ++++--
 .../ethernet/qualcomm/rmnet/rmnet_config.c    | 11 ++++--
 drivers/net/geneve.c                          | 11 ++++--
 drivers/net/gtp.c                             |  9 +++--
 drivers/net/ipvlan/ipvlan.h                   |  4 +-
 drivers/net/ipvlan/ipvlan_main.c              | 11 ++++--
 drivers/net/ipvlan/ipvtap.c                   |  7 ++--
 drivers/net/macsec.c                          | 11 ++++--
 drivers/net/macvlan.c                         |  8 ++--
 drivers/net/macvtap.c                         |  8 ++--
 drivers/net/netkit.c                          | 11 ++++--
 drivers/net/pfcp.c                            |  8 ++--
 drivers/net/ppp/ppp_generic.c                 | 10 +++--
 drivers/net/team/team_core.c                  |  7 ++--
 drivers/net/veth.c                            | 11 ++++--
 drivers/net/vrf.c                             |  7 ++--
 drivers/net/vxlan/vxlan_core.c                | 11 ++++--
 drivers/net/wireguard/device.c                |  8 ++--
 drivers/net/wireless/virtual/virt_wifi.c      | 10 +++--
 drivers/net/wwan/wwan_core.c                  | 15 +++++--
 include/net/ip_tunnels.h                      |  5 ++-
 include/net/rtnetlink.h                       | 34 +++++++++++++---
 net/8021q/vlan_netlink.c                      | 11 ++++--
 net/batman-adv/soft-interface.c               |  8 ++--
 net/bridge/br_netlink.c                       |  8 ++--
 net/caif/chnl_net.c                           |  6 +--
 net/core/rtnetlink.c                          | 29 +++++++++-----
 net/hsr/hsr_netlink.c                         | 14 ++++---
 net/ieee802154/6lowpan/core.c                 |  9 +++--
 net/ipv4/ip_gre.c                             | 27 ++++++++-----
 net/ipv4/ip_tunnel.c                          | 16 ++++----
 net/ipv4/ip_vti.c                             | 10 +++--
 net/ipv4/ipip.c                               | 10 +++--
 net/ipv6/ip6_gre.c                            | 28 +++++++------
 net/ipv6/ip6_tunnel.c                         | 16 ++++----
 net/ipv6/ip6_vti.c                            | 15 ++++---
 net/ipv6/sit.c                                | 16 ++++----
 net/xfrm/xfrm_interface_core.c                | 14 +++----
 tools/testing/selftests/net/Makefile          |  1 +
 .../testing/selftests/net/lib/py/__init__.py  |  2 +-
 tools/testing/selftests/net/lib/py/netns.py   | 18 +++++++++
 tools/testing/selftests/net/netns-name.sh     | 10 +++++
 tools/testing/selftests/net/netns_atomic.py   | 39 +++++++++++++++++++
 48 files changed, 377 insertions(+), 205 deletions(-)
 create mode 100755 tools/testing/selftests/net/netns_atomic.py

-- 
2.47.0

[PATCH net-next v4 1/5] net: ip_tunnel: Build flow in underlay net namespace

[Xiao Liang]

Build IPv4 flow in underlay net namespace, where encapsulated packets
are routed.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
---
 net/ipv4/ip_tunnel.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 25505f9b724c..09b73acf037a 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -294,7 +294,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev)
 
 		ip_tunnel_init_flow(&fl4, iph->protocol, iph->daddr,
 				    iph->saddr, tunnel->parms.o_key,
-				    iph->tos & INET_DSCP_MASK, dev_net(dev),
+				    iph->tos & INET_DSCP_MASK, tunnel->net,
 				    tunnel->parms.link, tunnel->fwmark, 0, 0);
 		rt = ip_route_output_key(tunnel->net, &fl4);
 
@@ -611,7 +611,7 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 	}
 	ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src,
 			    tunnel_id_to_key32(key->tun_id),
-			    tos & INET_DSCP_MASK, dev_net(dev), 0, skb->mark,
+			    tos & INET_DSCP_MASK, tunnel->net, 0, skb->mark,
 			    skb_get_hash(skb), key->flow_flags);
 
 	if (!tunnel_hlen)
@@ -774,7 +774,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
 
 	ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr,
 			    tunnel->parms.o_key, tos & INET_DSCP_MASK,
-			    dev_net(dev), READ_ONCE(tunnel->parms.link),
+			    tunnel->net, READ_ONCE(tunnel->parms.link),
 			    tunnel->fwmark, skb_get_hash(skb), 0);
 
 	if (ip_tunnel_encap(skb, &tunnel->encap, &protocol, &fl4) < 0)
-- 
2.47.0

[PATCH net-next v4 2/5] rtnetlink: Lookup device in target netns when creating link

[Xiao Liang]

When creating link, lookup for existing device in target net namespace
instead of current one.
For example, two links created by:

  # ip link add dummy1 type dummy
  # ip link add netns ns1 dummy1 type dummy

should have no conflict since they are in different namespaces.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
---
 net/core/rtnetlink.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index dd142f444659..bc9d0ecd3a1e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3846,20 +3846,26 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
 	struct nlattr ** const tb = tbs->tb;
 	struct net *net = sock_net(skb->sk);
+	struct net *device_net;
 	struct net_device *dev;
 	struct ifinfomsg *ifm;
 	bool link_specified;
 
+	/* When creating, lookup for existing device in target net namespace */
+	device_net = (nlh->nlmsg_flags & NLM_F_CREATE) &&
+		     (nlh->nlmsg_flags & NLM_F_EXCL) ?
+		     tgt_net : net;
+
 	ifm = nlmsg_data(nlh);
 	if (ifm->ifi_index > 0) {
 		link_specified = true;
-		dev = __dev_get_by_index(net, ifm->ifi_index);
+		dev = __dev_get_by_index(device_net, ifm->ifi_index);
 	} else if (ifm->ifi_index < 0) {
 		NL_SET_ERR_MSG(extack, "ifindex can't be negative");
 		return -EINVAL;
 	} else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME]) {
 		link_specified = true;
-		dev = rtnl_dev_get(net, tb);
+		dev = rtnl_dev_get(device_net, tb);
 	} else {
 		link_specified = false;
 		dev = NULL;
-- 
2.47.0

[PATCH net-next v4 3/5] rtnetlink: Decouple net namespaces in rtnl_newlink_create()

[Xiao Liang]

There are three net namespaces involved when creating links:

 - source netns - where the netlink socket resides,
 - target netns - where to put the device being created,
 - link netns - netns associated with the device (backend).

Currently, two nets are passed to newlink() callback - "src_net"
parameter and "dev_net" (implicitly in net_device). They are set as
follows, depending on whether IFLA_LINK_NETNSID is present.

 +-------------------+---------+---------+
 | IFLA_LINK_NETNSID | src_net | dev_net |
 +-------------------+---------+---------+
 | absent            | source  | target  |
 +-------------------+---------+---------+
 | present           | link    | link    |
 +-------------------+---------+---------+

When IFLA_LINK_NETNSID is present, the device is created in link netns
first. This has some side effects, including extra ifindex allocation,
ifname validation and link notifications. There's also an extra step to
move the device to target netns. These could be avoided if we create it
in target netns at the beginning.

On the other hand, the meaning of src_net is ambiguous. It should be
the effective link netns by design, but some drivers ignore it and use
dev_net instead.

This patch refactors netns handling by packing newlink() parameters into
a struct, and passing source and link netns as is through this struct.
rtnl_newlink_create() now creates devices in target netns directly, so
dev_net is always target netns.

When determining the effective link netns, in the absence link_net,
drivers should look for src_net in general. But for compatibility,
drivers that use dev_net will keep current behavior.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
---

There're some issues found when coverting drivers. Please check if they
work as intended:

- In amt_newlink() drivers/net/amt.c:

    amt->net = net;
    ...
    amt->stream_dev = dev_get_by_index(net, ...

  Uses net (src_net actually), but amt_lookup_upper_dev() only searches
  in dev_net.

- In gtp_newlink() in drivers/net/gtp.c:

    gtp->net = src_net;
    ...
    gn = net_generic(dev_net(dev), gtp_net_id);
    list_add_rcu(&gtp->list, &gn->gtp_dev_list);

  Uses src_net, but is linked to list in dev_net.

- In pfcp_newlink() in drivers/net/pfcp.c:

    pfcp->net = net;
    ...
    pn = net_generic(dev_net(dev), pfcp_net_id);
    list_add_rcu(&pfcp->list, &pn->pfcp_dev_list);

  Same.

- In lowpan_newlink() in net/ieee802154/6lowpan/core.c:

    wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));

  Looks for IFLA_LINK in dev_net, but in theory the ifindex is defined
  in link netns.

---

 drivers/infiniband/ulp/ipoib/ipoib_netlink.c  | 11 +++---
 drivers/net/amt.c                             | 13 ++++---
 drivers/net/bareudp.c                         | 11 +++---
 drivers/net/bonding/bond_netlink.c            |  8 +++--
 drivers/net/can/dev/netlink.c                 |  4 +--
 drivers/net/can/vxcan.c                       | 11 +++---
 .../ethernet/qualcomm/rmnet/rmnet_config.c    | 11 +++---
 drivers/net/geneve.c                          | 11 +++---
 drivers/net/gtp.c                             |  9 ++---
 drivers/net/ipvlan/ipvlan.h                   |  4 +--
 drivers/net/ipvlan/ipvlan_main.c              | 11 +++---
 drivers/net/ipvlan/ipvtap.c                   |  7 ++--
 drivers/net/macsec.c                          | 11 +++---
 drivers/net/macvlan.c                         |  8 ++---
 drivers/net/macvtap.c                         |  8 ++---
 drivers/net/netkit.c                          | 11 +++---
 drivers/net/pfcp.c                            |  8 ++---
 drivers/net/ppp/ppp_generic.c                 | 10 +++---
 drivers/net/team/team_core.c                  |  7 ++--
 drivers/net/veth.c                            | 11 +++---
 drivers/net/vrf.c                             |  7 ++--
 drivers/net/vxlan/vxlan_core.c                | 11 +++---
 drivers/net/wireguard/device.c                |  8 ++---
 drivers/net/wireless/virtual/virt_wifi.c      | 10 +++---
 drivers/net/wwan/wwan_core.c                  | 15 +++++---
 include/net/ip_tunnels.h                      |  5 +--
 include/net/rtnetlink.h                       | 34 ++++++++++++++++---
 net/8021q/vlan_netlink.c                      | 11 +++---
 net/batman-adv/soft-interface.c               |  8 ++---
 net/bridge/br_netlink.c                       |  8 +++--
 net/caif/chnl_net.c                           |  6 ++--
 net/core/rtnetlink.c                          | 19 ++++++-----
 net/hsr/hsr_netlink.c                         | 14 ++++----
 net/ieee802154/6lowpan/core.c                 |  9 ++---
 net/ipv4/ip_gre.c                             | 27 ++++++++++-----
 net/ipv4/ip_tunnel.c                          | 10 +++---
 net/ipv4/ip_vti.c                             | 10 +++---
 net/ipv4/ipip.c                               | 10 +++---
 net/ipv6/ip6_gre.c                            | 28 ++++++++-------
 net/ipv6/ip6_tunnel.c                         | 16 ++++-----
 net/ipv6/ip6_vti.c                            | 15 ++++----
 net/ipv6/sit.c                                | 16 ++++-----
 net/xfrm/xfrm_interface_core.c                | 14 ++++----
 43 files changed, 297 insertions(+), 199 deletions(-)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_netlink.c b/drivers/infiniband/ulp/ipoib/ipoib_netlink.c
index 9ad8d9856275..da587af85d4f 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_netlink.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_netlink.c
@@ -97,10 +97,13 @@ static int ipoib_changelink(struct net_device *dev, struct nlattr *tb[],
 	return ret;
 }
 
-static int ipoib_new_child_link(struct net *src_net, struct net_device *dev,
-				struct nlattr *tb[], struct nlattr *data[],
-				struct netlink_ext_ack *extack)
+static int ipoib_new_child_link(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct net_device *pdev;
 	struct ipoib_dev_priv *ppriv;
 	u16 child_pkey;
@@ -109,7 +112,7 @@ static int ipoib_new_child_link(struct net *src_net, struct net_device *dev,
 	if (!tb[IFLA_LINK])
 		return -EINVAL;
 
-	pdev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+	pdev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
 	if (!pdev || pdev->type != ARPHRD_INFINIBAND)
 		return -ENODEV;
 
diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index 98c6205ed19f..2f7bf50e05d2 100644
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -3161,14 +3161,17 @@ static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
-static int amt_newlink(struct net *net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
+static int amt_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct amt_dev *amt = netdev_priv(dev);
 	int err = -EINVAL;
 
-	amt->net = net;
+	amt->net = link_net;
 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
 
 	if (data[IFLA_AMT_MAX_TUNNELS] &&
@@ -3183,7 +3186,7 @@ static int amt_newlink(struct net *net, struct net_device *dev,
 	amt->hash_buckets = AMT_HSIZE;
 	amt->nr_tunnels = 0;
 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
-	amt->stream_dev = dev_get_by_index(net,
+	amt->stream_dev = dev_get_by_index(link_net,
 					   nla_get_u32(data[IFLA_AMT_LINK]));
 	if (!amt->stream_dev) {
 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index a2abfade82dd..49ff79498129 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c
@@ -698,10 +698,13 @@ static void bareudp_dellink(struct net_device *dev, struct list_head *head)
 	unregister_netdevice_queue(dev, head);
 }
 
-static int bareudp_newlink(struct net *net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[],
-			   struct netlink_ext_ack *extack)
+static int bareudp_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct bareudp_conf conf;
 	int err;
 
@@ -709,7 +712,7 @@ static int bareudp_newlink(struct net *net, struct net_device *dev,
 	if (err)
 		return err;
 
-	err = bareudp_configure(net, dev, &conf, extack);
+	err = bareudp_configure(link_net, dev, &conf, extack);
 	if (err)
 		return err;
 
diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index 2a6a424806aa..db3062c6dbe0 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -564,10 +564,12 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
 	return 0;
 }
 
-static int bond_newlink(struct net *src_net, struct net_device *bond_dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int bond_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *bond_dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
 	int err;
 
 	err = bond_changelink(bond_dev, tb, data, extack);
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index 01aacdcda260..52dae0e94858 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -624,9 +624,7 @@ static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
 	return -EMSGSIZE;
 }
 
-static int can_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
+static int can_newlink(struct rtnl_newlink_params *params)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c
index da7c72105fb6..8727701d5055 100644
--- a/drivers/net/can/vxcan.c
+++ b/drivers/net/can/vxcan.c
@@ -172,10 +172,13 @@ static void vxcan_setup(struct net_device *dev)
 /* forward declaration for rtnl_create_link() */
 static struct rtnl_link_ops vxcan_link_ops;
 
-static int vxcan_newlink(struct net *net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
-			 struct netlink_ext_ack *extack)
+static int vxcan_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct vxcan_priv *priv;
 	struct net_device *peer;
 	struct net *peer_net;
@@ -203,7 +206,7 @@ static int vxcan_newlink(struct net *net, struct net_device *dev,
 		name_assign_type = NET_NAME_ENUM;
 	}
 
-	peer_net = rtnl_link_get_net(net, tbp);
+	peer_net = rtnl_link_get_net(link_net, tbp);
 	peer = rtnl_create_link(peer_net, ifname, name_assign_type,
 				&vxcan_link_ops, tbp, extack);
 	if (IS_ERR(peer)) {
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
index f3bea196a8f9..d45555d784e6 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
@@ -117,10 +117,13 @@ static void rmnet_unregister_bridge(struct rmnet_port *port)
 	rmnet_unregister_real_device(bridge_dev);
 }
 
-static int rmnet_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
-			 struct netlink_ext_ack *extack)
+static int rmnet_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	u32 data_format = RMNET_FLAGS_INGRESS_DEAGGREGATION;
 	struct net_device *real_dev;
 	int mode = RMNET_EPMODE_VND;
@@ -134,7 +137,7 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev,
 		return -EINVAL;
 	}
 
-	real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+	real_dev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
 	if (!real_dev) {
 		NL_SET_ERR_MSG_MOD(extack, "link does not exist");
 		return -ENODEV;
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 2f29b1386b1c..a74962d5f066 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -1614,10 +1614,13 @@ static void geneve_link_config(struct net_device *dev,
 	geneve_change_mtu(dev, ldev_mtu - info->options_len);
 }
 
-static int geneve_newlink(struct net *net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int geneve_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct geneve_config cfg = {
 		.df = GENEVE_DF_UNSET,
 		.use_udp6_rx_checksums = false,
@@ -1631,7 +1634,7 @@ static int geneve_newlink(struct net *net, struct net_device *dev,
 	if (err)
 		return err;
 
-	err = geneve_configure(net, dev, extack, &cfg);
+	err = geneve_configure(link_net, dev, extack, &cfg);
 	if (err)
 		return err;
 
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 89a996ad8cd0..3eb1bc3ac124 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -1460,10 +1460,11 @@ static int gtp_create_sockets(struct gtp_dev *gtp, const struct nlattr *nla,
 #define GTP_TH_MAXLEN	(sizeof(struct udphdr) + sizeof(struct gtp0_header))
 #define GTP_IPV6_MAXLEN	(sizeof(struct ipv6hdr) + GTP_TH_MAXLEN)
 
-static int gtp_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
+static int gtp_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	unsigned int role = GTP_ROLE_GGSN;
 	struct gtp_dev *gtp;
 	struct gtp_net *gn;
@@ -1494,7 +1495,7 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
 	gtp->restart_count = nla_get_u8_default(data[IFLA_GTP_RESTART_COUNT],
 						0);
 
-	gtp->net = src_net;
+	gtp->net = link_net;
 
 	err = gtp_hashtable_new(gtp, hashsize);
 	if (err < 0)
diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h
index 025e0c19ec25..beff25a1d6f0 100644
--- a/drivers/net/ipvlan/ipvlan.h
+++ b/drivers/net/ipvlan/ipvlan.h
@@ -166,9 +166,7 @@ struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
 void *ipvlan_get_L3_hdr(struct ipvl_port *port, struct sk_buff *skb, int *type);
 void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
 		     unsigned int len, bool success, bool mcast);
-int ipvlan_link_new(struct net *src_net, struct net_device *dev,
-		    struct nlattr *tb[], struct nlattr *data[],
-		    struct netlink_ext_ack *extack);
+int ipvlan_link_new(struct rtnl_newlink_params *params);
 void ipvlan_link_delete(struct net_device *dev, struct list_head *head);
 void ipvlan_link_setup(struct net_device *dev);
 int ipvlan_link_register(struct rtnl_link_ops *ops);
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index ee2c3cf4df36..53860e9d08b1 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -532,10 +532,13 @@ static int ipvlan_nl_fillinfo(struct sk_buff *skb,
 	return ret;
 }
 
-int ipvlan_link_new(struct net *src_net, struct net_device *dev,
-		    struct nlattr *tb[], struct nlattr *data[],
-		    struct netlink_ext_ack *extack)
+int ipvlan_link_new(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct ipvl_dev *ipvlan = netdev_priv(dev);
 	struct ipvl_port *port;
 	struct net_device *phy_dev;
@@ -545,7 +548,7 @@ int ipvlan_link_new(struct net *src_net, struct net_device *dev,
 	if (!tb[IFLA_LINK])
 		return -EINVAL;
 
-	phy_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+	phy_dev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
 	if (!phy_dev)
 		return -ENODEV;
 
diff --git a/drivers/net/ipvlan/ipvtap.c b/drivers/net/ipvlan/ipvtap.c
index 1afc4c47be73..69e7456a48ca 100644
--- a/drivers/net/ipvlan/ipvtap.c
+++ b/drivers/net/ipvlan/ipvtap.c
@@ -73,10 +73,9 @@ static void ipvtap_update_features(struct tap_dev *tap,
 	netdev_update_features(vlan->dev);
 }
 
-static int ipvtap_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int ipvtap_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
 	struct ipvtap_dev *vlantap = netdev_priv(dev);
 	int err;
 
@@ -97,7 +96,7 @@ static int ipvtap_newlink(struct net *src_net, struct net_device *dev,
 	/* Don't put anything that may fail after macvlan_common_newlink
 	 * because we can't undo what it does.
 	 */
-	err =  ipvlan_link_new(src_net, dev, tb, data, extack);
+	err =  ipvlan_link_new(params);
 	if (err) {
 		netdev_rx_handler_unregister(dev);
 		return err;
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 1bc1e5993f56..e8b147fe4fce 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -4141,10 +4141,13 @@ static int macsec_add_dev(struct net_device *dev, sci_t sci, u8 icv_len)
 
 static struct lock_class_key macsec_netdev_addr_lock_key;
 
-static int macsec_newlink(struct net *net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int macsec_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct macsec_dev *macsec = macsec_priv(dev);
 	rx_handler_func_t *rx_handler;
 	u8 icv_len = MACSEC_DEFAULT_ICV_LEN;
@@ -4154,7 +4157,7 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 
 	if (!tb[IFLA_LINK])
 		return -EINVAL;
-	real_dev = __dev_get_by_index(net, nla_get_u32(tb[IFLA_LINK]));
+	real_dev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
 	if (!real_dev)
 		return -ENODEV;
 	if (real_dev->type != ARPHRD_ETHER)
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index fed4fe2a4748..7050a061b2b9 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1565,11 +1565,11 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(macvlan_common_newlink);
 
-static int macvlan_newlink(struct net *src_net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[],
-			   struct netlink_ext_ack *extack)
+static int macvlan_newlink(struct rtnl_newlink_params *params)
 {
-	return macvlan_common_newlink(src_net, dev, tb, data, extack);
+	return macvlan_common_newlink(rtnl_newlink_link_net(params),
+				      params->dev, params->tb, params->data,
+				      params->extack);
 }
 
 void macvlan_dellink(struct net_device *dev, struct list_head *head)
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 29a5929d48e5..213a16719c5a 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -77,10 +77,9 @@ static void macvtap_update_features(struct tap_dev *tap,
 	netdev_update_features(vlan->dev);
 }
 
-static int macvtap_newlink(struct net *src_net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[],
-			   struct netlink_ext_ack *extack)
+static int macvtap_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
 	struct macvtap_dev *vlantap = netdev_priv(dev);
 	int err;
 
@@ -105,7 +104,8 @@ static int macvtap_newlink(struct net *src_net, struct net_device *dev,
 	/* Don't put anything that may fail after macvlan_common_newlink
 	 * because we can't undo what it does.
 	 */
-	err = macvlan_common_newlink(src_net, dev, tb, data, extack);
+	err = macvlan_common_newlink(rtnl_newlink_link_net(params), dev,
+				     params->tb, params->data, params->extack);
 	if (err) {
 		netdev_rx_handler_unregister(dev);
 		return err;
diff --git a/drivers/net/netkit.c b/drivers/net/netkit.c
index bb07725d1c72..a50cdbe97588 100644
--- a/drivers/net/netkit.c
+++ b/drivers/net/netkit.c
@@ -327,10 +327,13 @@ static int netkit_validate(struct nlattr *tb[], struct nlattr *data[],
 
 static struct rtnl_link_ops netkit_link_ops;
 
-static int netkit_new_link(struct net *src_net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[],
-			   struct netlink_ext_ack *extack)
+static int netkit_new_link(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp = tb, *attr;
 	enum netkit_action policy_prim = NETKIT_PASS;
 	enum netkit_action policy_peer = NETKIT_PASS;
@@ -385,7 +388,7 @@ static int netkit_new_link(struct net *src_net, struct net_device *dev,
 	    (tb[IFLA_ADDRESS] || tbp[IFLA_ADDRESS]))
 		return -EOPNOTSUPP;
 
-	net = rtnl_link_get_net(src_net, tbp);
+	net = rtnl_link_get_net(link_net, tbp);
 	peer = rtnl_create_link(net, ifname, ifname_assign_type,
 				&netkit_link_ops, tbp, extack);
 	if (IS_ERR(peer)) {
diff --git a/drivers/net/pfcp.c b/drivers/net/pfcp.c
index 69434fd13f96..8576d5117233 100644
--- a/drivers/net/pfcp.c
+++ b/drivers/net/pfcp.c
@@ -184,15 +184,15 @@ static int pfcp_add_sock(struct pfcp_dev *pfcp)
 	return PTR_ERR_OR_ZERO(pfcp->sock);
 }
 
-static int pfcp_newlink(struct net *net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int pfcp_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct pfcp_dev *pfcp = netdev_priv(dev);
 	struct pfcp_net *pn;
 	int err;
 
-	pfcp->net = net;
+	pfcp->net = link_net;
 
 	err = pfcp_add_sock(pfcp);
 	if (err) {
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 4583e15ad03a..a0ace8aa5b5d 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1303,10 +1303,12 @@ static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
-static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int ppp_nl_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct ppp_config conf = {
 		.unit = -1,
 		.ifname_is_set = true,
@@ -1343,7 +1345,7 @@ static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
 	if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME]))
 		conf.ifname_is_set = false;
 
-	err = ppp_dev_configure(src_net, dev, &conf);
+	err = ppp_dev_configure(link_net, dev, &conf);
 
 out_unlock:
 	mutex_unlock(&ppp_mutex);
diff --git a/drivers/net/team/team_core.c b/drivers/net/team/team_core.c
index a1b27b69f010..c9ee70030517 100644
--- a/drivers/net/team/team_core.c
+++ b/drivers/net/team/team_core.c
@@ -2206,10 +2206,11 @@ static void team_setup(struct net_device *dev)
 	dev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 }
 
-static int team_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int team_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+
 	if (tb[IFLA_ADDRESS] == NULL)
 		eth_hw_addr_random(dev);
 
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 0d6d0d749d44..90f8a773a256 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1765,10 +1765,13 @@ static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
 	return 0;
 }
 
-static int veth_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int veth_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	int err;
 	struct net_device *peer;
 	struct veth_priv *priv;
@@ -1800,7 +1803,7 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
 		name_assign_type = NET_NAME_ENUM;
 	}
 
-	net = rtnl_link_get_net(src_net, tbp);
+	net = rtnl_link_get_net(link_net, tbp);
 	peer = rtnl_create_link(net, ifname, name_assign_type,
 				&veth_link_ops, tbp, extack);
 	if (IS_ERR(peer)) {
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 67d25f4f94ef..f45bc224fd15 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -1698,10 +1698,11 @@ static void vrf_dellink(struct net_device *dev, struct list_head *head)
 	unregister_netdevice_queue(dev, head);
 }
 
-static int vrf_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
+static int vrf_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
 	struct net_vrf *vrf = netdev_priv(dev);
 	struct netns_vrf *nn_vrf;
 	bool *add_fib_rules;
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 9ea63059d52d..ba16ff9b1553 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -4351,10 +4351,13 @@ static int vxlan_nl2conf(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
-static int vxlan_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
-			 struct netlink_ext_ack *extack)
+static int vxlan_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct vxlan_config conf;
 	int err;
 
@@ -4362,7 +4365,7 @@ static int vxlan_newlink(struct net *src_net, struct net_device *dev,
 	if (err)
 		return err;
 
-	return __vxlan_dev_create(src_net, dev, &conf, extack);
+	return __vxlan_dev_create(link_net, dev, &conf, extack);
 }
 
 static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c
index 45e9b908dbfb..3e22f715422b 100644
--- a/drivers/net/wireguard/device.c
+++ b/drivers/net/wireguard/device.c
@@ -306,14 +306,14 @@ static void wg_setup(struct net_device *dev)
 	wg->dev = dev;
 }
 
-static int wg_newlink(struct net *src_net, struct net_device *dev,
-		      struct nlattr *tb[], struct nlattr *data[],
-		      struct netlink_ext_ack *extack)
+static int wg_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct wg_device *wg = netdev_priv(dev);
 	int ret = -ENOMEM;
 
-	rcu_assign_pointer(wg->creating_net, src_net);
+	rcu_assign_pointer(wg->creating_net, link_net);
 	init_rwsem(&wg->static_identity.lock);
 	mutex_init(&wg->socket_update_lock);
 	mutex_init(&wg->device_update_lock);
diff --git a/drivers/net/wireless/virtual/virt_wifi.c b/drivers/net/wireless/virtual/virt_wifi.c
index 4ee374080466..107dc503b4f2 100644
--- a/drivers/net/wireless/virtual/virt_wifi.c
+++ b/drivers/net/wireless/virtual/virt_wifi.c
@@ -519,10 +519,12 @@ static rx_handler_result_t virt_wifi_rx_handler(struct sk_buff **pskb)
 }
 
 /* Called with rtnl lock held. */
-static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
-			     struct nlattr *tb[], struct nlattr *data[],
-			     struct netlink_ext_ack *extack)
+static int virt_wifi_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
 	int err;
 
@@ -532,7 +534,7 @@ static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
 	netif_carrier_off(dev);
 
 	priv->upperdev = dev;
-	priv->lowerdev = __dev_get_by_index(src_net,
+	priv->lowerdev = __dev_get_by_index(link_net,
 					    nla_get_u32(tb[IFLA_LINK]));
 
 	if (!priv->lowerdev)
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index a51e2755991a..450cf2e253e4 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c
@@ -967,10 +967,11 @@ static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[],
 	return dev;
 }
 
-static int wwan_rtnl_newlink(struct net *src_net, struct net_device *dev,
-			     struct nlattr *tb[], struct nlattr *data[],
-			     struct netlink_ext_ack *extack)
+static int wwan_rtnl_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
 	struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent);
 	u32 link_id = nla_get_u32(data[IFLA_WWAN_LINK_ID]);
 	struct wwan_netdev_priv *priv = netdev_priv(dev);
@@ -1064,6 +1065,11 @@ static void wwan_create_default_link(struct wwan_device *wwandev,
 	struct net_device *dev;
 	struct nlmsghdr *nlh;
 	struct sk_buff *msg;
+	struct rtnl_newlink_params params = {
+		.src_net = &init_net,
+		.tb = tb,
+		.data = data,
+	};
 
 	/* Forge attributes required to create a WWAN netdev. We first
 	 * build a netlink message and then parse it. This looks
@@ -1105,7 +1111,8 @@ static void wwan_create_default_link(struct wwan_device *wwandev,
 	if (WARN_ON(IS_ERR(dev)))
 		goto unlock;
 
-	if (WARN_ON(wwan_rtnl_newlink(&init_net, dev, tb, data, NULL))) {
+	params.dev = dev;
+	if (WARN_ON(wwan_rtnl_newlink(&params))) {
 		free_netdev(dev);
 		goto unlock;
 	}
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/include/net/rtnetlink.h b/include/net/rtnetlink.h
index bc0069a8b6ea..fb28e538dd2d 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -69,6 +69,34 @@ static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
 		return AF_UNSPEC;
 }
 
+/**
+ *	struct rtnl_newlink_params - parameters of rtnl_link_ops::newlink()
+ *
+ *	@src_net: Source netns of rtnetlink socket
+ *	@link_net: Link netns by IFLA_LINK_NETNSID, NULL if not specified
+ *	@dev: The net_device being created
+ *	@tb: IFLA_* attributes
+ *	@data: IFLA_INFO_DATA attributes
+ *	@extack: Netlink extended ACK
+ */
+struct rtnl_newlink_params {
+	struct net *src_net;
+	struct net *link_net;
+	struct net_device *dev;
+	struct nlattr **tb;
+	struct nlattr **data;
+	struct netlink_ext_ack *extack;
+};
+
+/* Get effective link netns from newlink params. Generally, this is link_net
+ * and falls back to src_net. But for compatibility, a driver may * choose to
+ * use dev_net(dev) instead.
+ */
+static inline struct net *rtnl_newlink_link_net(struct rtnl_newlink_params *p)
+{
+	return p->link_net ? : p->src_net;
+}
+
 /**
  *	struct rtnl_link_ops - rtnetlink link operations
  *
@@ -125,11 +153,7 @@ struct rtnl_link_ops {
 					    struct nlattr *data[],
 					    struct netlink_ext_ack *extack);
 
-	int			(*newlink)(struct net *src_net,
-					   struct net_device *dev,
-					   struct nlattr *tb[],
-					   struct nlattr *data[],
-					   struct netlink_ext_ack *extack);
+	int			(*newlink)(struct rtnl_newlink_params *params);
 	int			(*changelink)(struct net_device *dev,
 					      struct nlattr *tb[],
 					      struct nlattr *data[],
diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
index 134419667d59..603b2ea1e2b4 100644
--- a/net/8021q/vlan_netlink.c
+++ b/net/8021q/vlan_netlink.c
@@ -135,10 +135,13 @@ static int vlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	return 0;
 }
 
-static int vlan_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int vlan_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct net_device *real_dev;
 	unsigned int max_mtu;
@@ -155,7 +158,7 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
 		return -EINVAL;
 	}
 
-	real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+	real_dev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
 	if (!real_dev) {
 		NL_SET_ERR_MSG_MOD(extack, "link does not exist");
 		return -ENODEV;
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 2758aba47a2f..12eb939cf0e4 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -1063,7 +1063,7 @@ static int batadv_softif_validate(struct nlattr *tb[], struct nlattr *data[],
 
 /**
  * batadv_softif_newlink() - pre-initialize and register new batadv link
- * @src_net: the applicable net namespace
+ * @nets: the applicable net namespaces
  * @dev: network device to register
  * @tb: IFLA_INFO_DATA netlink attributes
  * @data: enum batadv_ifla_attrs attributes
@@ -1071,10 +1071,10 @@ static int batadv_softif_validate(struct nlattr *tb[], struct nlattr *data[],
  *
  * Return: 0 if successful or error otherwise.
  */
-static int batadv_softif_newlink(struct net *src_net, struct net_device *dev,
-				 struct nlattr *tb[], struct nlattr *data[],
-				 struct netlink_ext_ack *extack)
+static int batadv_softif_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
 	struct batadv_priv *bat_priv = netdev_priv(dev);
 	const char *algo_name;
 	int err;
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 3e0f47203f2a..ccce5119b28d 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1553,10 +1553,12 @@ static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
 	return 0;
 }
 
-static int br_dev_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int br_dev_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
 	struct net_bridge *br = netdev_priv(dev);
 	int err;
 
diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
index 94ad09e36df2..748e38908709 100644
--- a/net/caif/chnl_net.c
+++ b/net/caif/chnl_net.c
@@ -438,10 +438,10 @@ static void caif_netlink_parms(struct nlattr *data[],
 	}
 }
 
-static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int ipcaif_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
 	int ret;
 	struct chnl_net *caifdev;
 	ASSERT_RTNL();
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index bc9d0ecd3a1e..232ddce447b7 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3750,6 +3750,13 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 	struct net_device *dev;
 	char ifname[IFNAMSIZ];
 	int err;
+	struct rtnl_newlink_params params = {
+		.src_net = net,
+		.link_net = link_net,
+		.tb = tb,
+		.data = data,
+		.extack = extack,
+	};
 
 	if (!ops->alloc && !ops->setup)
 		return -EOPNOTSUPP;
@@ -3761,17 +3768,18 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 		name_assign_type = NET_NAME_ENUM;
 	}
 
-	dev = rtnl_create_link(link_net ? : tgt_net, ifname,
-			       name_assign_type, ops, tb, extack);
+	dev = rtnl_create_link(tgt_net, ifname, name_assign_type, ops, tb,
+			       extack);
 	if (IS_ERR(dev)) {
 		err = PTR_ERR(dev);
 		goto out;
 	}
 
 	dev->ifindex = ifm->ifi_index;
+	params.dev = dev;
 
 	if (ops->newlink)
-		err = ops->newlink(link_net ? : net, dev, tb, data, extack);
+		err = ops->newlink(&params);
 	else
 		err = register_netdevice(dev);
 	if (err < 0) {
@@ -3782,11 +3790,6 @@ static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
 	err = rtnl_configure_link(dev, ifm, portid, nlh);
 	if (err < 0)
 		goto out_unregister;
-	if (link_net) {
-		err = dev_change_net_namespace(dev, tgt_net, ifname);
-		if (err < 0)
-			goto out_unregister;
-	}
 	if (tb[IFLA_MASTER]) {
 		err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]), extack);
 		if (err)
diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
index b68f2f71d0e1..694392222637 100644
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -29,10 +29,12 @@ static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
 /* Here, it seems a netdevice has already been allocated for us, and the
  * hsr_dev_setup routine has been executed. Nice!
  */
-static int hsr_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
+static int hsr_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *link_net = rtnl_newlink_link_net(params);
 	enum hsr_version proto_version;
 	unsigned char multicast_spec;
 	u8 proto = HSR_PROTOCOL_HSR;
@@ -46,7 +48,7 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 		NL_SET_ERR_MSG_MOD(extack, "Slave1 device not specified");
 		return -EINVAL;
 	}
-	link[0] = __dev_get_by_index(src_net,
+	link[0] = __dev_get_by_index(link_net,
 				     nla_get_u32(data[IFLA_HSR_SLAVE1]));
 	if (!link[0]) {
 		NL_SET_ERR_MSG_MOD(extack, "Slave1 does not exist");
@@ -56,7 +58,7 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 		NL_SET_ERR_MSG_MOD(extack, "Slave2 device not specified");
 		return -EINVAL;
 	}
-	link[1] = __dev_get_by_index(src_net,
+	link[1] = __dev_get_by_index(link_net,
 				     nla_get_u32(data[IFLA_HSR_SLAVE2]));
 	if (!link[1]) {
 		NL_SET_ERR_MSG_MOD(extack, "Slave2 does not exist");
@@ -69,7 +71,7 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 	}
 
 	if (data[IFLA_HSR_INTERLINK])
-		interlink = __dev_get_by_index(src_net,
+		interlink = __dev_get_by_index(link_net,
 					       nla_get_u32(data[IFLA_HSR_INTERLINK]));
 
 	if (interlink && interlink == link[0]) {
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index 175efd860f7b..65a5c61cf38c 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -129,10 +129,10 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
-static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int lowpan_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *ldev = params->dev;
+	struct nlattr **tb = params->tb;
 	struct net_device *wdev;
 	int ret;
 
@@ -143,7 +143,8 @@ static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
 	if (!tb[IFLA_LINK])
 		return -EINVAL;
 	/* find and hold wpan device */
-	wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
+	wdev = dev_get_by_index(params->link_net ? : dev_net(ldev),
+				nla_get_u32(tb[IFLA_LINK]));
 	if (!wdev)
 		return -ENODEV;
 	if (wdev->type != ARPHRD_IEEE802154) {
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index f1f31ebfc793..4a3f8e450ef5 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1389,10 +1389,12 @@ ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
 	return 0;
 }
 
-static int ipgre_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
-			 struct netlink_ext_ack *extack)
+static int ipgre_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip_tunnel_parm_kern p;
 	__u32 fwmark = 0;
 	int err;
@@ -1404,13 +1406,15 @@ static int ipgre_newlink(struct net *src_net, 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(net, dev, tb, &p, fwmark);
 }
 
-static int erspan_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int erspan_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip_tunnel_parm_kern p;
 	__u32 fwmark = 0;
 	int err;
@@ -1422,7 +1426,7 @@ static int erspan_newlink(struct net *src_net, struct net_device *dev,
 	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(net, dev, tb, &p, fwmark);
 }
 
 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
@@ -1695,6 +1699,10 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	LIST_HEAD(list_kill);
 	struct ip_tunnel *t;
 	int err;
+	struct rtnl_newlink_params params = {
+		.src_net = net,
+		.tb = tb,
+	};
 
 	memset(&tb, 0, sizeof(tb));
 
@@ -1707,7 +1715,8 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	t = netdev_priv(dev);
 	t->collect_md = true;
 
-	err = ipgre_newlink(net, dev, tb, NULL, NULL);
+	params.dev = dev;
+	err = ipgre_newlink(&params);
 	if (err < 0) {
 		free_netdev(dev);
 		return ERR_PTR(err);
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);
+
 	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 f0b4419cef34..b567e2375302 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -575,15 +575,17 @@ static void vti_netlink_parms(struct nlattr *data[],
 		*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 }
 
-static int vti_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
+static int vti_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
 	struct ip_tunnel_parm_kern parms;
 	__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 dc0db5895e0e..9dccaa0d6ba7 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -436,10 +436,11 @@ static void ipip_netlink_parms(struct nlattr *data[],
 		*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
 }
 
-static int ipip_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int ipip_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
 	struct ip_tunnel *t = netdev_priv(dev);
 	struct ip_tunnel_encap ipencap;
 	struct ip_tunnel_parm_kern p;
@@ -453,7 +454,8 @@ static int ipip_newlink(struct net *src_net, struct net_device *dev,
 	}
 
 	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[],
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 235808cfec70..7d6d3db200a1 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1971,7 +1971,7 @@ static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
 	return ret;
 }
 
-static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
+static int ip6gre_newlink_common(struct net *link_net, struct net_device *dev,
 				 struct nlattr *tb[], struct nlattr *data[],
 				 struct netlink_ext_ack *extack)
 {
@@ -1992,7 +1992,7 @@ static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
 		eth_hw_addr_random(dev);
 
 	nt->dev = dev;
-	nt->net = dev_net(dev);
+	nt->net = link_net;
 
 	err = register_netdevice(dev);
 	if (err)
@@ -2005,12 +2005,14 @@ static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
 	return err;
 }
 
-static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
-			  struct nlattr *tb[], struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int ip6gre_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
 	struct ip6_tnl *nt = netdev_priv(dev);
-	struct net *net = dev_net(dev);
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip6gre_net *ign;
 	int err;
 
@@ -2025,7 +2027,7 @@ static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
 			return -EEXIST;
 	}
 
-	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+	err = ip6gre_newlink_common(net, dev, tb, data, extack);
 	if (!err) {
 		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
 		ip6gre_tunnel_link_md(ign, nt);
@@ -2241,12 +2243,14 @@ static void ip6erspan_tap_setup(struct net_device *dev)
 	netif_keep_dst(dev);
 }
 
-static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
-			     struct nlattr *tb[], struct nlattr *data[],
-			     struct netlink_ext_ack *extack)
+static int ip6erspan_newlink(struct rtnl_newlink_params *params)
 {
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
 	struct ip6_tnl *nt = netdev_priv(dev);
-	struct net *net = dev_net(dev);
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip6gre_net *ign;
 	int err;
 
@@ -2262,7 +2266,7 @@ static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
 			return -EEXIST;
 	}
 
-	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+	err = ip6gre_newlink_common(net, dev, tb, data, extack);
 	if (!err) {
 		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
 		ip6erspan_tunnel_link_md(ign, nt);
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 48fd53b98972..33a58c3c9ebe 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -250,10 +250,9 @@ static void ip6_dev_free(struct net_device *dev)
 	dst_cache_destroy(&t->dst_cache);
 }
 
-static int ip6_tnl_create2(struct net_device *dev)
+static int ip6_tnl_create2(struct net *net, struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net *net = dev_net(dev);
 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 	int err;
 
@@ -308,7 +307,7 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 	t = netdev_priv(dev);
 	t->parms = *p;
 	t->net = dev_net(dev);
-	err = ip6_tnl_create2(dev);
+	err = ip6_tnl_create2(net, dev);
 	if (err < 0)
 		goto failed_free;
 
@@ -2002,11 +2001,12 @@ static void ip6_tnl_netlink_parms(struct nlattr *data[],
 		parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
 }
 
-static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
-			   struct nlattr *tb[], struct nlattr *data[],
-			   struct netlink_ext_ack *extack)
+static int ip6_tnl_newlink(struct rtnl_newlink_params *params)
 {
-	struct net *net = dev_net(dev);
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 	struct ip_tunnel_encap ipencap;
 	struct ip6_tnl *nt, *t;
@@ -2031,7 +2031,7 @@ static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
 			return -EEXIST;
 	}
 
-	err = ip6_tnl_create2(dev);
+	err = ip6_tnl_create2(net, dev);
 	if (!err && tb[IFLA_MTU])
 		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
 
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 590737c27537..ff9dc74819c5 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -174,10 +174,9 @@ vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
 	}
 }
 
-static int vti6_tnl_create2(struct net_device *dev)
+static int vti6_tnl_create2(struct net *net, struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
-	struct net *net = dev_net(dev);
 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 	int err;
 
@@ -221,7 +220,7 @@ static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p
 	t->parms = *p;
 	t->net = dev_net(dev);
 
-	err = vti6_tnl_create2(dev);
+	err = vti6_tnl_create2(net, dev);
 	if (err < 0)
 		goto failed_free;
 
@@ -997,11 +996,11 @@ static void vti6_netlink_parms(struct nlattr *data[],
 		parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 }
 
-static int vti6_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int vti6_newlink(struct rtnl_newlink_params *params)
 {
-	struct net *net = dev_net(dev);
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip6_tnl *nt;
 
 	nt = netdev_priv(dev);
@@ -1012,7 +1011,7 @@ static int vti6_newlink(struct net *src_net, struct net_device *dev,
 	if (vti6_locate(net, &nt->parms, 0))
 		return -EEXIST;
 
-	return vti6_tnl_create2(dev);
+	return vti6_tnl_create2(net, dev);
 }
 
 static void vti6_dellink(struct net_device *dev, struct list_head *head)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 39bd8951bfca..cbcaccbfc3c9 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -198,10 +198,9 @@ static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 #endif
 }
 
-static int ipip6_tunnel_create(struct net_device *dev)
+static int ipip6_tunnel_create(struct net *net, struct net_device *dev)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
-	struct net *net = dev_net(dev);
 	struct sit_net *sitn = net_generic(net, sit_net_id);
 	int err;
 
@@ -270,7 +269,7 @@ static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 	nt = netdev_priv(dev);
 
 	nt->parms = *parms;
-	if (ipip6_tunnel_create(dev) < 0)
+	if (ipip6_tunnel_create(net, dev) < 0)
 		goto failed_free;
 
 	if (!parms->name[0])
@@ -1550,11 +1549,12 @@ static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
 }
 #endif
 
-static int ipip6_newlink(struct net *src_net, struct net_device *dev,
-			 struct nlattr *tb[], struct nlattr *data[],
-			 struct netlink_ext_ack *extack)
+static int ipip6_newlink(struct rtnl_newlink_params *params)
 {
-	struct net *net = dev_net(dev);
+	struct net_device *dev = params->dev;
+	struct nlattr **tb = params->tb;
+	struct nlattr **data = params->data;
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct ip_tunnel *nt;
 	struct ip_tunnel_encap ipencap;
 #ifdef CONFIG_IPV6_SIT_6RD
@@ -1575,7 +1575,7 @@ static int ipip6_newlink(struct net *src_net, struct net_device *dev,
 	if (ipip6_tunnel_locate(net, &nt->parms, 0))
 		return -EEXIST;
 
-	err = ipip6_tunnel_create(dev);
+	err = ipip6_tunnel_create(net, dev);
 	if (err < 0)
 		return err;
 
diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c
index 98f1e2b67c76..d1f2674a98c8 100644
--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -242,10 +242,9 @@ static void xfrmi_dev_free(struct net_device *dev)
 	gro_cells_destroy(&xi->gro_cells);
 }
 
-static int xfrmi_create(struct net_device *dev)
+static int xfrmi_create(struct net *net, struct net_device *dev)
 {
 	struct xfrm_if *xi = netdev_priv(dev);
-	struct net *net = dev_net(dev);
 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
 	int err;
 
@@ -814,11 +813,12 @@ static void xfrmi_netlink_parms(struct nlattr *data[],
 		parms->collect_md = true;
 }
 
-static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
-			struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int xfrmi_newlink(struct rtnl_newlink_params *params)
 {
-	struct net *net = dev_net(dev);
+	struct net_device *dev = params->dev;
+	struct nlattr **data = params->data;
+	struct netlink_ext_ack *extack = params->extack;
+	struct net *net = params->link_net ? : dev_net(dev);
 	struct xfrm_if_parms p = {};
 	struct xfrm_if *xi;
 	int err;
@@ -851,7 +851,7 @@ static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
 	xi->net = net;
 	xi->dev = dev;
 
-	err = xfrmi_create(dev);
+	err = xfrmi_create(net, dev);
 	return err;
 }
 
-- 
2.47.0

[PATCH net-next v4 4/5] selftests: net: Add python context manager for netns entering

[Xiao Liang]

Change netns of current thread and switch back on context exit.
For example:

    with NetNSEnter("ns1"):
        ip("link add dummy0 type dummy")

The command be executed in netns "ns1".

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
---
 tools/testing/selftests/net/lib/py/__init__.py |  2 +-
 tools/testing/selftests/net/lib/py/netns.py    | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/lib/py/__init__.py b/tools/testing/selftests/net/lib/py/__init__.py
index 54d8f5eba810..e2d6c7b63019 100644
--- a/tools/testing/selftests/net/lib/py/__init__.py
+++ b/tools/testing/selftests/net/lib/py/__init__.py
@@ -2,7 +2,7 @@
 
 from .consts import KSRC
 from .ksft import *
-from .netns import NetNS
+from .netns import NetNS, NetNSEnter
 from .nsim import *
 from .utils import *
 from .ynl import NlError, YnlFamily, EthtoolFamily, NetdevFamily, RtnlFamily
diff --git a/tools/testing/selftests/net/lib/py/netns.py b/tools/testing/selftests/net/lib/py/netns.py
index ecff85f9074f..8e9317044eef 100644
--- a/tools/testing/selftests/net/lib/py/netns.py
+++ b/tools/testing/selftests/net/lib/py/netns.py
@@ -1,9 +1,12 @@
 # SPDX-License-Identifier: GPL-2.0
 
 from .utils import ip
+import ctypes
 import random
 import string
 
+libc = ctypes.cdll.LoadLibrary('libc.so.6')
+
 
 class NetNS:
     def __init__(self, name=None):
@@ -29,3 +32,18 @@ class NetNS:
 
     def __repr__(self):
         return f"NetNS({self.name})"
+
+
+class NetNSEnter:
+    def __init__(self, ns_name):
+        self.ns_path = f"/run/netns/{ns_name}"
+
+    def __enter__(self):
+        self.saved = open("/proc/thread-self/ns/net")
+        with open(self.ns_path) as ns_file:
+            libc.setns(ns_file.fileno(), 0)
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        libc.setns(self.saved.fileno(), 0)
+        self.saved.close()
-- 
2.47.0

[PATCH net-next v4 5/5] selftests: net: Add two test cases for link netns

[Xiao Liang]

 - Add test for creating link in another netns when a link of the same
   name and ifindex exists in current netns.
 - Add test for link netns atomicity - create link directly in target
   netns, and no notifications should be generated in current netns.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
---
 tools/testing/selftests/net/Makefile        |  1 +
 tools/testing/selftests/net/netns-name.sh   | 10 ++++++
 tools/testing/selftests/net/netns_atomic.py | 39 +++++++++++++++++++++
 3 files changed, 50 insertions(+)
 create mode 100755 tools/testing/selftests/net/netns_atomic.py

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 3d487b03c4a0..3aaa7950b0f0 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -34,6 +34,7 @@ TEST_PROGS += gre_gso.sh
 TEST_PROGS += cmsg_so_mark.sh
 TEST_PROGS += cmsg_time.sh cmsg_ipv6.sh
 TEST_PROGS += netns-name.sh
+TEST_PROGS += netns_atomic.py
 TEST_PROGS += nl_netdev.py
 TEST_PROGS += srv6_end_dt46_l3vpn_test.sh
 TEST_PROGS += srv6_end_dt4_l3vpn_test.sh
diff --git a/tools/testing/selftests/net/netns-name.sh b/tools/testing/selftests/net/netns-name.sh
index 6974474c26f3..0be1905d1f2f 100755
--- a/tools/testing/selftests/net/netns-name.sh
+++ b/tools/testing/selftests/net/netns-name.sh
@@ -78,6 +78,16 @@ ip -netns $NS link show dev $ALT_NAME 2> /dev/null &&
     fail "Can still find alt-name after move"
 ip -netns $test_ns link del $DEV || fail
 
+#
+# Test no conflict of the same name/ifindex in different netns
+#
+ip -netns $NS link add name $DEV index 100 type dummy || fail
+ip -netns $NS link add netns $test_ns name $DEV index 100 type dummy ||
+    fail "Can create in netns without moving"
+ip -netns $test_ns link show dev $DEV >> /dev/null || fail "Device not found"
+ip -netns $NS link del $DEV || fail
+ip -netns $test_ns link del $DEV || fail
+
 echo -ne "$(basename $0) \t\t\t\t"
 if [ $RET_CODE -eq 0 ]; then
     echo "[  OK  ]"
diff --git a/tools/testing/selftests/net/netns_atomic.py b/tools/testing/selftests/net/netns_atomic.py
new file mode 100755
index 000000000000..d350a3fc0a91
--- /dev/null
+++ b/tools/testing/selftests/net/netns_atomic.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import time
+
+from lib.py import ksft_run, ksft_exit, ksft_true
+from lib.py import ip
+from lib.py import NetNS, NetNSEnter
+from lib.py import RtnlFamily
+
+
+def test_event(ns1, ns2) -> None:
+    with NetNSEnter(str(ns1)):
+        rtnl = RtnlFamily()
+
+    rtnl.ntf_subscribe("rtnlgrp-link")
+
+    ip(f"netns set {ns1} 0", ns=str(ns2))
+
+    ip(f"link add netns {ns2} link-netnsid 0 dummy1 type dummy")
+    ip(f"link add netns {ns2} dummy2 type dummy", ns=str(ns1))
+
+    ip("link del dummy1", ns=str(ns2))
+    ip("link del dummy2", ns=str(ns2))
+
+    time.sleep(1)
+    rtnl.check_ntf()
+    ksft_true(rtnl.async_msg_queue.empty(),
+              "Received unexpected link notification")
+
+
+def main() -> None:
+    with NetNS() as ns1, NetNS() as ns2:
+        ksft_run([test_event], args=(ns1, ns2))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()
-- 
2.47.0

Re: [PATCH net-next v4 0/5] net: Improve netns handling in RTNL and ip_tunnel

[Jakub Kicinski]

On Mon, 18 Nov 2024 22:32:39 +0800 Xiao Liang wrote:
> This patch series includes some netns-related improvements and fixes for
> RTNL and ip_tunnel, to make link creation more intuitive:
> 
>  - Creating link in another net namespace doesn't conflict with link names
>    in current one.
>  - Refector rtnetlink link creation. Create link in target namespace
>    directly. Pass both source and link netns to drivers via newlink()
>    callback.
> 
> So that
> 
>   # ip link add netns ns1 link-netns ns2 tun0 type gre ...
> 
> will create tun0 in ns1, rather than create it in ns2 and move to ns1.
> And don't conflict with another interface named "tun0" in current netns.

## Form letter - net-next-closed

The merge window for v6.13 has begun and net-next is closed for new drivers,
features, code refactoring and optimizations. We are currently accepting
bug fixes only.

Please repost when net-next reopens after Dec 2nd.

RFC patches sent for review only are welcome at any time.

See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
-- 
pw-bot: defer