Commit 38a3889f authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ipv4-fix-bugs-when-enable-route_localnet' 



Shijie Luo says:

====================
ipv4: fix bugs when enable route_localnet

When enable route_localnet, route of the 127/8 address is enabled.
But in some situations like arp_announce=2, ARP requests or reply
work abnormally.

This patchset fix some bugs when enable route_localnet.

Change History:
V2:
- Change a single patch to a patchset.
- Add bug fix for arp_ignore = 3.
- Add a couple of test for enabling route_localnet in selftests.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 8bc81c57 58ade67b

net/ipv4/devinet.c

+13 −3
Original line number Diff line number Diff line
@@ -1287,6 +1287,7 @@ __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope) 
{

	const struct in_ifaddr *ifa;

	__be32 addr = 0;

	unsigned char localnet_scope = RT_SCOPE_HOST;

	struct in_device *in_dev;

	struct net *net = dev_net(dev);

	int master_idx;
@@ -1296,10 +1297,13 @@ __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope) 
	if (!in_dev)

		goto no_in_dev;



	if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev)))

		localnet_scope = RT_SCOPE_LINK;



	in_dev_for_each_ifa_rcu(ifa, in_dev) {

		if (ifa->ifa_flags & IFA_F_SECONDARY)

			continue;

		if (ifa->ifa_scope > scope)

		if (min(ifa->ifa_scope, localnet_scope) > scope)

			continue;

		if (!dst || inet_ifa_match(dst, ifa)) {

			addr = ifa->ifa_local;
@@ -1352,14 +1356,20 @@ EXPORT_SYMBOL(inet_select_addr); 
static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,

			      __be32 local, int scope)

{

	unsigned char localnet_scope = RT_SCOPE_HOST;

	const struct in_ifaddr *ifa;

	__be32 addr = 0;

	int same = 0;



	if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev)))

		localnet_scope = RT_SCOPE_LINK;



	in_dev_for_each_ifa_rcu(ifa, in_dev) {

		unsigned char min_scope = min(ifa->ifa_scope, localnet_scope);



		if (!addr &&

		    (local == ifa->ifa_local || !local) &&

		    ifa->ifa_scope <= scope) {

		    min_scope <= scope) {

			addr = ifa->ifa_local;

			if (same)

				break;
@@ -1374,7 +1384,7 @@ static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst, 
				if (inet_ifa_match(addr, ifa))

					break;

				/* No, then can we use new local src? */

				if (ifa->ifa_scope <= scope) {

				if (min_scope <= scope) {

					addr = ifa->ifa_local;

					break;

				}

tools/testing/selftests/net/route_localnet.sh

0 → 100755
+74 −0
Original line number Diff line number Diff line 
#!/bin/bash

# SPDX-License-Identifier: GPL-2.0

#

# Run a couple of tests when route_localnet = 1.



readonly PEER_NS="ns-peer-$(mktemp -u XXXXXX)"



setup() {

    ip netns add "${PEER_NS}"

    ip -netns "${PEER_NS}" link set dev lo up

    ip link add name veth0 type veth peer name veth1

    ip link set dev veth0 up

    ip link set dev veth1 netns "${PEER_NS}"



    # Enable route_localnet and delete useless route 127.0.0.0/8.

    sysctl -w net.ipv4.conf.veth0.route_localnet=1

    ip netns exec "${PEER_NS}" sysctl -w net.ipv4.conf.veth1.route_localnet=1

    ip route del 127.0.0.0/8 dev lo table local

    ip netns exec "${PEER_NS}" ip route del 127.0.0.0/8 dev lo table local



    ifconfig veth0 127.25.3.4/24 up

    ip netns exec "${PEER_NS}" ifconfig veth1 127.25.3.14/24 up



    ip route flush cache

    ip netns exec "${PEER_NS}" ip route flush cache

}



cleanup() {

    ip link del veth0

    ip route add local 127.0.0.0/8 dev lo proto kernel scope host src 127.0.0.1

    local -r ns="$(ip netns list|grep $PEER_NS)"

    [ -n "$ns" ] && ip netns del $ns 2>/dev/null

}



# Run test when arp_announce = 2.

run_arp_announce_test() {

    echo "run arp_announce test"

    setup



    sysctl -w net.ipv4.conf.veth0.arp_announce=2

    ip netns exec "${PEER_NS}" sysctl -w net.ipv4.conf.veth1.arp_announce=2

    ping -c5 -I veth0 127.25.3.14

    if [ $? -ne 0 ];then

        echo "failed"

    else

        echo "ok"

    fi



    cleanup

}



# Run test when arp_ignore = 3.

run_arp_ignore_test() {

    echo "run arp_ignore test"

    setup



    sysctl -w net.ipv4.conf.veth0.arp_ignore=3

    ip netns exec "${PEER_NS}" sysctl -w net.ipv4.conf.veth1.arp_ignore=3

    ping -c5 -I veth0 127.25.3.14

    if [ $? -ne 0 ];then

        echo "failed"

    else

        echo "ok"

    fi



    cleanup

}



run_all_tests() {

    run_arp_announce_test

    run_arp_ignore_test

}



run_all_tests

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