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Commit 38e01b30 authored by Nicolas Dichtel's avatar Nicolas Dichtel Committed by David S. Miller
Browse files

dev: advertise the new ifindex when the netns iface changes 



The goal is to let the user follow an interface that moves to another
netns.

CC: Jiri Benc <jbenc@redhat.com>
CC: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: default avatarJiri Benc <jbenc@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c36ac8e2

include/linux/rtnetlink.h

+3 −2
Original line number Diff line number Diff line
@@ -19,10 +19,11 @@ extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, 


void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags);

void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,

			 gfp_t flags, int *new_nsid);

			 gfp_t flags, int *new_nsid, int new_ifindex);

struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,

				       unsigned change, u32 event,

				       gfp_t flags, int *new_nsid);

				       gfp_t flags, int *new_nsid,

				       int new_ifindex);

void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,

		       gfp_t flags);

include/uapi/linux/if_link.h

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ enum { 
	IFLA_IF_NETNSID,

	IFLA_CARRIER_UP_COUNT,

	IFLA_CARRIER_DOWN_COUNT,

	IFLA_NEW_IFINDEX,

	__IFLA_MAX

};

net/core/dev.c

+12 −7
Original line number Diff line number Diff line
@@ -7360,7 +7360,7 @@ static void rollback_registered_many(struct list_head *head) 
		if (!dev->rtnl_link_ops ||

		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)

			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,

						     GFP_KERNEL, NULL);

						     GFP_KERNEL, NULL, 0);



		/*

		 *	Flush the unicast and multicast chains
@@ -8473,7 +8473,7 @@ EXPORT_SYMBOL(unregister_netdev); 


int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)

{

	int err, new_nsid;

	int err, new_nsid, new_ifindex;



	ASSERT_RTNL();
@@ -8529,8 +8529,16 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char 
	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);

	rcu_barrier();

	call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);



	new_nsid = peernet2id_alloc(dev_net(dev), net);

	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid);

	/* If there is an ifindex conflict assign a new one */

	if (__dev_get_by_index(net, dev->ifindex))

		new_ifindex = dev_new_index(net);

	else

		new_ifindex = dev->ifindex;



	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,

			    new_ifindex);



	/*

	 *	Flush the unicast and multicast chains
@@ -8544,10 +8552,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char 


	/* Actually switch the network namespace */

	dev_net_set(dev, net);



	/* If there is an ifindex conflict assign a new one */

	if (__dev_get_by_index(net, dev->ifindex))

		dev->ifindex = dev_new_index(net);

	dev->ifindex = new_ifindex;



	/* Send a netdev-add uevent to the new namespace */

	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);

net/core/rtnetlink.c

+20 −11
Original line number Diff line number Diff line
@@ -988,6 +988,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, 
	       + rtnl_xdp_size() /* IFLA_XDP */

	       + nla_total_size(4)  /* IFLA_EVENT */

	       + nla_total_size(4)  /* IFLA_NEW_NETNSID */

	       + nla_total_size(4)  /* IFLA_NEW_IFINDEX */

	       + nla_total_size(1)  /* IFLA_PROTO_DOWN */

	       + nla_total_size(4)  /* IFLA_IF_NETNSID */

	       + nla_total_size(4)  /* IFLA_CARRIER_UP_COUNT */
@@ -1511,7 +1512,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, 
			    struct net_device *dev, struct net *src_net,

			    int type, u32 pid, u32 seq, u32 change,

			    unsigned int flags, u32 ext_filter_mask,

			    u32 event, int *new_nsid, int tgt_netnsid)

			    u32 event, int *new_nsid, int new_ifindex,

			    int tgt_netnsid)

{

	struct ifinfomsg *ifm;

	struct nlmsghdr *nlh;
@@ -1608,6 +1610,10 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, 
	if (new_nsid &&

	    nla_put_s32(skb, IFLA_NEW_NETNSID, *new_nsid) < 0)

		goto nla_put_failure;

	if (new_ifindex &&

	    nla_put_s32(skb, IFLA_NEW_IFINDEX, new_ifindex) < 0)

		goto nla_put_failure;





	rcu_read_lock();

	if (rtnl_fill_link_af(skb, dev, ext_filter_mask))
@@ -1853,7 +1859,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) 
					       NETLINK_CB(cb->skb).portid,

					       cb->nlh->nlmsg_seq, 0,

					       flags,

					       ext_filter_mask, 0, NULL,

					       ext_filter_mask, 0, NULL, 0,

					       netnsid);



			if (err < 0) {
@@ -3088,7 +3094,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, 
	err = rtnl_fill_ifinfo(nskb, dev, net,

			       RTM_NEWLINK, NETLINK_CB(skb).portid,

			       nlh->nlmsg_seq, 0, 0, ext_filter_mask,

			       0, NULL, netnsid);

			       0, NULL, 0, netnsid);

	if (err < 0) {

		/* -EMSGSIZE implies BUG in if_nlmsg_size */

		WARN_ON(err == -EMSGSIZE);
@@ -3184,7 +3190,8 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) 


struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,

				       unsigned int change,

				       u32 event, gfp_t flags, int *new_nsid)

				       u32 event, gfp_t flags, int *new_nsid,

				       int new_ifindex)

{

	struct net *net = dev_net(dev);

	struct sk_buff *skb;
@@ -3197,7 +3204,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev, 


	err = rtnl_fill_ifinfo(skb, dev, dev_net(dev),

			       type, 0, 0, change, 0, 0, event,

			       new_nsid, -1);

			       new_nsid, new_ifindex, -1);

	if (err < 0) {

		/* -EMSGSIZE implies BUG in if_nlmsg_size() */

		WARN_ON(err == -EMSGSIZE);
@@ -3220,14 +3227,15 @@ void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev, gfp_t flags) 


static void rtmsg_ifinfo_event(int type, struct net_device *dev,

			       unsigned int change, u32 event,

			       gfp_t flags, int *new_nsid)

			       gfp_t flags, int *new_nsid, int new_ifindex)

{

	struct sk_buff *skb;



	if (dev->reg_state != NETREG_REGISTERED)

		return;



	skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid);

	skb = rtmsg_ifinfo_build_skb(type, dev, change, event, flags, new_nsid,

				     new_ifindex);

	if (skb)

		rtmsg_ifinfo_send(skb, dev, flags);

}
@@ -3235,14 +3243,15 @@ static void rtmsg_ifinfo_event(int type, struct net_device *dev, 
void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,

		  gfp_t flags)

{

	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags, NULL);

	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,

			   NULL, 0);

}



void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,

			 gfp_t flags, int *new_nsid)

			 gfp_t flags, int *new_nsid, int new_ifindex)

{

	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags,

			   new_nsid);

			   new_nsid, new_ifindex);

}



static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
@@ -4642,7 +4651,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi 
	case NETDEV_CHANGELOWERSTATE:

	case NETDEV_CHANGE_TX_QUEUE_LEN:

		rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, rtnl_get_event(event),

				   GFP_KERNEL, NULL);

				   GFP_KERNEL, NULL, 0);

		break;

	default:

		break;