Commit 69c7be1b authored by Xiao Liang's avatar Xiao Liang Committed by Jakub Kicinski
Browse files

rtnetlink: Pack newlink() params into struct 



There are 4 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),
 - peer netns - netns of peer device.

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 netlink attributes in the request.

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

When IFLA_LINK_NETNSID is present, the device is created in link netns
first and then moved to target netns. This has some side effects,
including extra ifindex allocation, ifname validation and link events.
These could be avoided if we create it in target netns from
the beginning.

On the other hand, the meaning of src_net parameter is ambiguous. It
varies depending on how parameters are passed. It is the effective
link (or peer netns) by design, but some drivers ignore it and use
dev_net instead.

To provide more netns context for drivers, this patch packs existing
newlink() parameters, along with the source netns, link netns and peer
netns, into a struct. The old "src_net" is renamed to "net" to avoid
confusion with real source netns, and will be deprecated later. The use
of src_net are converted to params->net trivially.

Signed-off-by: default avatarXiao Liang <shaw.leon@gmail.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ec061546

drivers/infiniband/ulp/ipoib/ipoib_netlink.c

+5 −2
Original line number Diff line number Diff line
@@ -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[],

static int ipoib_new_child_link(struct net_device *dev,

				struct rtnl_newlink_params *params,

				struct netlink_ext_ack *extack)

{

	struct nlattr **data = params->data;

	struct net *src_net = params->net;

	struct nlattr **tb = params->tb;

	struct net_device *pdev;

	struct ipoib_dev_priv *ppriv;

	u16 child_pkey;

drivers/net/amt.c

+5 −2
Original line number Diff line number Diff line
@@ -3161,11 +3161,14 @@ 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[],

static int amt_newlink(struct net_device *dev,

		       struct rtnl_newlink_params *params,

		       struct netlink_ext_ack *extack)

{

	struct amt_dev *amt = netdev_priv(dev);

	struct nlattr **data = params->data;

	struct nlattr **tb = params->tb;

	struct net *net = params->net;

	int err = -EINVAL;



	amt->net = net;

drivers/net/bareudp.c

+5 −2
Original line number Diff line number Diff line
@@ -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[],

static int bareudp_newlink(struct net_device *dev,

			   struct rtnl_newlink_params *params,

			   struct netlink_ext_ack *extack)

{

	struct nlattr **data = params->data;

	struct nlattr **tb = params->tb;

	struct net *net = params->net;

	struct bareudp_conf conf;

	int err;

drivers/net/bonding/bond_netlink.c

+4 −2
Original line number Diff line number Diff line
@@ -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[],

static int bond_newlink(struct net_device *bond_dev,

			struct rtnl_newlink_params *params,

			struct netlink_ext_ack *extack)

{

	struct nlattr **data = params->data;

	struct nlattr **tb = params->tb;

	int err;



	err = bond_changelink(bond_dev, tb, data, extack);

drivers/net/can/dev/netlink.c

+2 −2
Original line number Diff line number Diff line
@@ -624,8 +624,8 @@ 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[],

static int can_newlink(struct net_device *dev,

		       struct rtnl_newlink_params *params,

		       struct netlink_ext_ack *extack)

{

	return -EOPNOTSUPP;