Merge branch 'net-ipv4-fixes-for-PMTU-when-link-MTU-changes' (28b6bfeb) · Commits · 戴 / test

include/linux/netdevice.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -2458,6 +2458,13 @@ struct netdev_notifier_info {
		struct netlink_ext_ack *extack;
		};

		struct netdev_notifier_info_ext {
		struct netdev_notifier_info info; /* must be first */
		union {
		u32 mtu;
		} ext;
		};

		struct netdev_notifier_change_info {
		struct netdev_notifier_info info; /* must be first */
		unsigned int flags_changed;

include/net/ip_fib.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -394,6 +394,7 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev);
		int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
		int fib_sync_down_addr(struct net_device *dev, __be32 local);
		int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
		void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);

		#ifdef CONFIG_IP_ROUTE_MULTIPATH
		int fib_multipath_hash(const struct net net, const struct flowi4 fl4,

net/core/dev.c

+26 −2

Original line number	Diff line number	Diff line
		@@ -1752,6 +1752,28 @@ int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
		}
		EXPORT_SYMBOL(call_netdevice_notifiers);

		/**
		* call_netdevice_notifiers_mtu - call all network notifier blocks
		* @val: value passed unmodified to notifier function
		* @dev: net_device pointer passed unmodified to notifier function
		* @arg: additional u32 argument passed to the notifier function
		*
		* Call all network notifier blocks. Parameters and return value
		* are as for raw_notifier_call_chain().
		*/
		static int call_netdevice_notifiers_mtu(unsigned long val,
		struct net_device *dev, u32 arg)
		{
		struct netdev_notifier_info_ext info = {
		.info.dev = dev,
		.ext.mtu = arg,
		};

		BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);

		return call_netdevice_notifiers_info(val, &info.info);
		}

		#ifdef CONFIG_NET_INGRESS
		static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);

		@@ -7574,14 +7596,16 @@ int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
		err = __dev_set_mtu(dev, new_mtu);

		if (!err) {
		err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
		orig_mtu);
		err = notifier_to_errno(err);
		if (err) {
		/* setting mtu back and notifying everyone again,
		* so that they have a chance to revert changes.
		*/
		__dev_set_mtu(dev, orig_mtu);
		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
		call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
		new_mtu);
		}
		}
		return err;

net/ipv4/fib_frontend.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1243,7 +1243,8 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
		static int fib_netdev_event(struct notifier_block this, unsigned long event, void ptr)
		{
		struct net_device *dev = netdev_notifier_info_to_dev(ptr);
		struct netdev_notifier_changeupper_info *info;
		struct netdev_notifier_changeupper_info *upper_info = ptr;
		struct netdev_notifier_info_ext *info_ext = ptr;
		struct in_device *in_dev;
		struct net *net = dev_net(dev);
		unsigned int flags;
		@@ -1278,16 +1279,19 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo
		fib_sync_up(dev, RTNH_F_LINKDOWN);
		else
		fib_sync_down_dev(dev, event, false);
		/* fall through */
		rt_cache_flush(net);
		break;
		case NETDEV_CHANGEMTU:
		fib_sync_mtu(dev, info_ext->ext.mtu);
		rt_cache_flush(net);
		break;
		case NETDEV_CHANGEUPPER:
		info = ptr;
		upper_info = ptr;
		/* flush all routes if dev is linked to or unlinked from
		* an L3 master device (e.g., VRF)
		*/
		if (info->upper_dev && netif_is_l3_master(info->upper_dev))
		if (upper_info->upper_dev &&
		netif_is_l3_master(upper_info->upper_dev))
		fib_disable_ip(dev, NETDEV_DOWN, true);
		break;
		}

net/ipv4/fib_semantics.c

+50 −0

Original line number	Diff line number	Diff line
		@@ -1470,6 +1470,56 @@ static int call_fib_nh_notifiers(struct fib_nh *fib_nh,
		return NOTIFY_DONE;
		}

		/* Update the PMTU of exceptions when:
		* - the new MTU of the first hop becomes smaller than the PMTU
		* - the old MTU was the same as the PMTU, and it limited discovery of
		* larger MTUs on the path. With that limit raised, we can now
		* discover larger MTUs
		* A special case is locked exceptions, for which the PMTU is smaller
		* than the minimal accepted PMTU:
		* - if the new MTU is greater than the PMTU, don't make any change
		* - otherwise, unlock and set PMTU
		*/
		static void nh_update_mtu(struct fib_nh *nh, u32 new, u32 orig)
		{
		struct fnhe_hash_bucket *bucket;
		int i;

		bucket = rcu_dereference_protected(nh->nh_exceptions, 1);
		if (!bucket)
		return;

		for (i = 0; i < FNHE_HASH_SIZE; i++) {
		struct fib_nh_exception *fnhe;

		for (fnhe = rcu_dereference_protected(bucket[i].chain, 1);
		fnhe;
		fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) {
		if (fnhe->fnhe_mtu_locked) {
		if (new <= fnhe->fnhe_pmtu) {
		fnhe->fnhe_pmtu = new;
		fnhe->fnhe_mtu_locked = false;
		}
		} else if (new < fnhe->fnhe_pmtu \|\|
		orig == fnhe->fnhe_pmtu) {
		fnhe->fnhe_pmtu = new;
		}
		}
		}
		}

		void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
		{
		unsigned int hash = fib_devindex_hashfn(dev->ifindex);
		struct hlist_head *head = &fib_info_devhash[hash];
		struct fib_nh *nh;

		hlist_for_each_entry(nh, head, nh_hash) {
		if (nh->nh_dev == dev)
		nh_update_mtu(nh, dev->mtu, orig_mtu);
		}
		}

		/* Event force Flags Description
		* NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
		* NETDEV_DOWN 0 LINKDOWN\|DEAD Link down, not for scope host

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