Commit ef56b640 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'mpls-notifications' 



Benjamin Poirier says:

====================
net: mpls: Netlink notification fixes

fix missing or inaccurate route notifications when devices used in
nexthops are deleted.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 817b6531 18916818

net/mpls/af_mpls.c

+62 −35
Original line number Diff line number Diff line
@@ -409,7 +409,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 
		goto err;



	/* Find the output device */

	out_dev = rcu_dereference(nh->nh_dev);

	out_dev = nh->nh_dev;

	if (!mpls_output_possible(out_dev))

		goto tx_err;
@@ -698,7 +698,7 @@ static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, 
	    (dev->addr_len != nh->nh_via_alen))

		goto errout;



	RCU_INIT_POINTER(nh->nh_dev, dev);

	nh->nh_dev = dev;



	if (!(dev->flags & IFF_UP)) {

		nh->nh_flags |= RTNH_F_DEAD;
@@ -1491,26 +1491,53 @@ static void mpls_dev_destroy_rcu(struct rcu_head *head) 
	kfree(mdev);

}



static void mpls_ifdown(struct net_device *dev, int event)

static int mpls_ifdown(struct net_device *dev, int event)

{

	struct mpls_route __rcu **platform_label;

	struct net *net = dev_net(dev);

	u8 alive, deleted;

	unsigned index;



	platform_label = rtnl_dereference(net->mpls.platform_label);

	for (index = 0; index < net->mpls.platform_labels; index++) {

		struct mpls_route *rt = rtnl_dereference(platform_label[index]);

		bool nh_del = false;

		u8 alive = 0;



		if (!rt)

			continue;



		alive = 0;

		deleted = 0;

		if (event == NETDEV_UNREGISTER) {

			u8 deleted = 0;



			for_nexthops(rt) {

				if (!nh->nh_dev || nh->nh_dev == dev)

					deleted++;

				if (nh->nh_dev == dev)

					nh_del = true;

			} endfor_nexthops(rt);



			/* if there are no more nexthops, delete the route */

			if (deleted == rt->rt_nhn) {

				mpls_route_update(net, index, NULL, NULL);

				continue;

			}



			if (nh_del) {

				size_t size = sizeof(*rt) + rt->rt_nhn *

					rt->rt_nh_size;

				struct mpls_route *orig = rt;



				rt = kmalloc(size, GFP_KERNEL);

				if (!rt)

					return -ENOMEM;

				memcpy(rt, orig, size);

			}

		}



		change_nexthops(rt) {

			unsigned int nh_flags = nh->nh_flags;



			if (rtnl_dereference(nh->nh_dev) != dev)

			if (nh->nh_dev != dev)

				goto next;



			switch (event) {
@@ -1523,23 +1550,22 @@ static void mpls_ifdown(struct net_device *dev, int event) 
				break;

			}

			if (event == NETDEV_UNREGISTER)

				RCU_INIT_POINTER(nh->nh_dev, NULL);

				nh->nh_dev = NULL;



			if (nh->nh_flags != nh_flags)

				WRITE_ONCE(nh->nh_flags, nh_flags);

next:

			if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))

				alive++;

			if (!rtnl_dereference(nh->nh_dev))

				deleted++;

		} endfor_nexthops(rt);



		WRITE_ONCE(rt->rt_nhn_alive, alive);



		/* if there are no more nexthops, delete the route */

		if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)

			mpls_route_update(net, index, NULL, NULL);

		if (nh_del)

			mpls_route_update(net, index, rt, NULL);

	}



	return 0;

}



static void mpls_ifup(struct net_device *dev, unsigned int flags)
@@ -1559,14 +1585,12 @@ static void mpls_ifup(struct net_device *dev, unsigned int flags) 
		alive = 0;

		change_nexthops(rt) {

			unsigned int nh_flags = nh->nh_flags;

			struct net_device *nh_dev =

				rtnl_dereference(nh->nh_dev);



			if (!(nh_flags & flags)) {

				alive++;

				continue;

			}

			if (nh_dev != dev)

			if (nh->nh_dev != dev)

				continue;

			alive++;

			nh_flags &= ~flags;
@@ -1597,8 +1621,12 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 
		return NOTIFY_OK;



	switch (event) {

		int err;



	case NETDEV_DOWN:

		mpls_ifdown(dev, event);

		err = mpls_ifdown(dev, event);

		if (err)

			return notifier_from_errno(err);

		break;

	case NETDEV_UP:

		flags = dev_get_flags(dev);
@@ -1609,13 +1637,18 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 
		break;

	case NETDEV_CHANGE:

		flags = dev_get_flags(dev);

		if (flags & (IFF_RUNNING | IFF_LOWER_UP))

		if (flags & (IFF_RUNNING | IFF_LOWER_UP)) {

			mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);

		else

			mpls_ifdown(dev, event);

		} else {

			err = mpls_ifdown(dev, event);

			if (err)

				return notifier_from_errno(err);

		}

		break;

	case NETDEV_UNREGISTER:

		mpls_ifdown(dev, event);

		err = mpls_ifdown(dev, event);

		if (err)

			return notifier_from_errno(err);

		mdev = mpls_dev_get(dev);

		if (mdev) {

			mpls_dev_sysctl_unregister(dev, mdev);
@@ -1626,8 +1659,6 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 
	case NETDEV_CHANGENAME:

		mdev = mpls_dev_get(dev);

		if (mdev) {

			int err;



			mpls_dev_sysctl_unregister(dev, mdev);

			err = mpls_dev_sysctl_register(dev, mdev);

			if (err)
@@ -1994,7 +2025,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 
		    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),

				nh->nh_via_alen))

			goto nla_put_failure;

		dev = rtnl_dereference(nh->nh_dev);

		dev = nh->nh_dev;

		if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))

			goto nla_put_failure;

		if (nh->nh_flags & RTNH_F_LINKDOWN)
@@ -2012,7 +2043,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 
			goto nla_put_failure;



		for_nexthops(rt) {

			dev = rtnl_dereference(nh->nh_dev);

			dev = nh->nh_dev;

			if (!dev)

				continue;
@@ -2123,18 +2154,14 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 
static bool mpls_rt_uses_dev(struct mpls_route *rt,

			     const struct net_device *dev)

{

	struct net_device *nh_dev;



	if (rt->rt_nhn == 1) {

		struct mpls_nh *nh = rt->rt_nh;



		nh_dev = rtnl_dereference(nh->nh_dev);

		if (dev == nh_dev)

		if (nh->nh_dev == dev)

			return true;

	} else {

		for_nexthops(rt) {

			nh_dev = rtnl_dereference(nh->nh_dev);

			if (nh_dev == dev)

			if (nh->nh_dev == dev)

				return true;

		} endfor_nexthops(rt);

	}
@@ -2222,7 +2249,7 @@ static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 
		size_t nhsize = 0;



		for_nexthops(rt) {

			if (!rtnl_dereference(nh->nh_dev))

			if (!nh->nh_dev)

				continue;

			nhsize += nla_total_size(sizeof(struct rtnexthop));

			/* RTA_VIA */
@@ -2468,7 +2495,7 @@ static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 
	    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),

			nh->nh_via_alen))

		goto nla_put_failure;

	dev = rtnl_dereference(nh->nh_dev);

	dev = nh->nh_dev;

	if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))

		goto nla_put_failure;
@@ -2507,7 +2534,7 @@ static int resize_platform_label_table(struct net *net, size_t limit) 
		rt0 = mpls_rt_alloc(1, lo->addr_len, 0);

		if (IS_ERR(rt0))

			goto nort0;

		RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);

		rt0->rt_nh->nh_dev = lo;

		rt0->rt_protocol = RTPROT_KERNEL;

		rt0->rt_payload_type = MPT_IPV4;

		rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
@@ -2521,7 +2548,7 @@ static int resize_platform_label_table(struct net *net, size_t limit) 
		rt2 = mpls_rt_alloc(1, lo->addr_len, 0);

		if (IS_ERR(rt2))

			goto nort2;

		RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);

		rt2->rt_nh->nh_dev = lo;

		rt2->rt_protocol = RTPROT_KERNEL;

		rt2->rt_payload_type = MPT_IPV6;

		rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;

net/mpls/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ enum mpls_payload_type { 
};



struct mpls_nh { /* next hop label forwarding entry */

	struct net_device __rcu *nh_dev;

	struct net_device	*nh_dev;



	/* nh_flags is accessed under RCU in the packet path; it is

	 * modified handling netdev events with rtnl lock held