diff mbox

[RFC,net-next,5/6] net: Delay initializations for lightweight devices

Message ID 20170506160734.47084-6-dsahern@gmail.com
State RFC, archived
Delegated to: David Miller
Headers show

Commit Message

David Ahern May 6, 2017, 4:07 p.m. UTC 
Delay ipv4 and ipv6 initializations on lightweight netdevices until an
address is added to the device.

Skip sysctl initialization for neighbor path as well.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/linux/netdevice.h |  5 +++++
 net/core/neighbour.c      |  3 +++
 net/ipv4/devinet.c        | 18 ++++++++++++++++--
 net/ipv6/addrconf.c       |  9 +++++++++
 net/mpls/af_mpls.c        |  6 ++++++
 5 files changed, 39 insertions(+), 2 deletions(-)

Comments

Florian Fainelli May 8, 2017, 5:31 p.m. UTC | #1 
On 05/06/2017 09:07 AM, David Ahern wrote:
> Delay ipv4 and ipv6 initializations on lightweight netdevices until an
> address is added to the device.
> 
> Skip sysctl initialization for neighbor path as well.

Yeah, thanks for including the sysctl initialization. One thing that my
earlier "L2 only" attempt attempted to solve as well, was to put the
IFF_NOIPV4 and IFF_NOIPV6 flags as volatile. In case you changed your
mind and ended-up needing IP stacks to be initialized, this ought to be
possible at some point. I did not get to test that part though.

AFAIR, some peculiar devices like 6lowpan (and to some extent the larger
802.15.4 family) may want to be IPv6 exclusively. This means we may have
a bit of overlap with flags like IFF_NOARP, (the proposed IFF_NOIPV6
before) and IFF_LWT_NETDEV.

Thanks!
diff mbox

Patch

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4ddd0ac7e1cb..32d155be777a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4144,6 +4144,11 @@  static inline bool netif_is_lwd(struct net_device *dev)
 	return !!(dev->priv_flags & IFF_LWT_NETDEV);
 }
 
+static inline bool netif_has_sysctl(struct net_device *dev)
+{
+	return !netif_is_lwd(dev);
+}
+
 static inline bool netif_is_macsec(const struct net_device *dev)
 {
 	return dev->priv_flags & IFF_MACSEC;
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 58b0bcc125b5..10104a7135e2 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3123,6 +3123,9 @@  int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 	char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
 	char *p_name;
 
+	if (dev && !netif_has_sysctl(dev))
+		return 0;
+
 	t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL);
 	if (!t)
 		goto err;
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index df14815a3b8c..c5ffd3ed4b2c 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -771,8 +771,15 @@  static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh,
 
 	in_dev = __in_dev_get_rtnl(dev);
 	err = -ENOBUFS;
-	if (!in_dev)
-		goto errout;
+	if (!in_dev) {
+		if (netif_is_lwd(dev)) {
+			in_dev = inetdev_init(dev);
+			if (IS_ERR(in_dev))
+				in_dev = NULL;
+		}
+		if (!in_dev)
+			goto errout;
+	}
 
 	ifa = inet_alloc_ifa();
 	if (!ifa)
@@ -1417,6 +1424,10 @@  static int inetdev_event(struct notifier_block *this, unsigned long event,
 
 	if (!in_dev) {
 		if (event == NETDEV_REGISTER) {
+			/* inet init is deferred for lightweight devices */
+			if (netif_is_lwd(dev))
+				goto out;
+
 			in_dev = inetdev_init(dev);
 			if (IS_ERR(in_dev))
 				return notifier_from_errno(PTR_ERR(in_dev));
@@ -2303,6 +2314,9 @@  static int devinet_sysctl_register(struct in_device *idev)
 {
 	int err;
 
+	if (!netif_has_sysctl(idev->dev))
+		return 0;
+
 	if (!sysctl_dev_name_is_allowed(idev->dev->name))
 		return -EINVAL;
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8d297a79b568..9814df6b7017 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3371,6 +3371,10 @@  static int addrconf_notify(struct notifier_block *this, unsigned long event,
 
 	switch (event) {
 	case NETDEV_REGISTER:
+		/* inet6 init is deferred for lightweight devices */
+		if (netif_is_lwd(dev))
+			return NOTIFY_OK;
+
 		if (!idev && dev->mtu >= IPV6_MIN_MTU) {
 			idev = ipv6_add_dev(dev);
 			if (IS_ERR(idev))
@@ -6368,6 +6372,11 @@  static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 	struct ctl_table *table;
 	char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
 
+	if (idev && idev->dev && !netif_has_sysctl(idev->dev)) {
+		p->sysctl_header = NULL;
+		return 0;
+	}
+
 	table = kmemdup(addrconf_sysctl, sizeof(addrconf_sysctl), GFP_KERNEL);
 	if (!table)
 		goto out;
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 088e2b459d0f..7503d68da2ea 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1251,6 +1251,9 @@  static int mpls_dev_sysctl_register(struct net_device *dev,
 	struct ctl_table *table;
 	int i;
 
+	if (!netif_has_sysctl(dev))
+		return 0;
+
 	table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
 	if (!table)
 		goto out;
@@ -1285,6 +1288,9 @@  static void mpls_dev_sysctl_unregister(struct net_device *dev,
 	struct net *net = dev_net(dev);
 	struct ctl_table *table;
 
+	if (!mdev->sysctl)
+		return;
+
 	table = mdev->sysctl->ctl_table_arg;
 	unregister_net_sysctl_table(mdev->sysctl);
 	kfree(table);