Commit dd357348 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ipv4-invalidate-broadcast-neigh-upon-address-addition' 

Ido Schimmel says:

====================
ipv4: Invalidate neighbour for broadcast address upon address addition

Patch #1 solves a recently reported issue [1]. See detailed description
in the changelog.

Patch #2 adds a matching test case.

Targeting at net-next since as far as I can tell this use case never
worked.

There are no regressions in fib_tests.sh with this change:

 # ./fib_tests.sh
 ...
 Tests passed: 186
 Tests failed:   0

[1] https://lore.kernel.org/netdev/55a04a8f-56f3-f73c-2aea-2195923f09d1@huawei.com/


====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 0f6938eb 25bd462f

include/net/arp.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ void arp_send(int type, int ptype, __be32 dest_ip, 
	      const unsigned char *src_hw, const unsigned char *th);

int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir);

void arp_ifdown(struct net_device *dev);

int arp_invalidate(struct net_device *dev, __be32 ip, bool force);



struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,

			   struct net_device *dev, __be32 src_ip,

net/ipv4/arp.c

+7 −2
Original line number Diff line number Diff line
@@ -1116,13 +1116,18 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev) 
	return err;

}



static int arp_invalidate(struct net_device *dev, __be32 ip)

int arp_invalidate(struct net_device *dev, __be32 ip, bool force)

{

	struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);

	int err = -ENXIO;

	struct neigh_table *tbl = &arp_tbl;



	if (neigh) {

		if ((neigh->nud_state & NUD_VALID) && !force) {

			neigh_release(neigh);

			return 0;

		}



		if (neigh->nud_state & ~NUD_NOARP)

			err = neigh_update(neigh, NULL, NUD_FAILED,

					   NEIGH_UPDATE_F_OVERRIDE|
@@ -1169,7 +1174,7 @@ static int arp_req_delete(struct net *net, struct arpreq *r, 
		if (!dev)

			return -EINVAL;

	}

	return arp_invalidate(dev, ip);

	return arp_invalidate(dev, ip, true);

}



/*

net/ipv4/fib_frontend.c

+4 −1
Original line number Diff line number Diff line
@@ -1124,9 +1124,11 @@ void fib_add_ifaddr(struct in_ifaddr *ifa) 
		return;



	/* Add broadcast address, if it is explicitly assigned. */

	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))

	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) {

		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,

			  prim, 0);

		arp_invalidate(dev, ifa->ifa_broadcast, false);

	}



	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&

	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
@@ -1140,6 +1142,7 @@ void fib_add_ifaddr(struct in_ifaddr *ifa) 
		if (ifa->ifa_prefixlen < 31) {

			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,

				  32, prim, 0);

			arp_invalidate(dev, prefix | ~mask, false);

		}

	}

}

tools/testing/selftests/net/fib_tests.sh

+57 −1
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ ret=0 
ksft_skip=4



# all tests in this script. Can be overridden with -t option

TESTS="unregister down carrier nexthop suppress ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle"

TESTS="unregister down carrier nexthop suppress ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle ipv4_bcast_neigh"



VERBOSE=0

PAUSE_ON_FAIL=no
@@ -1954,6 +1954,61 @@ ipv6_mangle_test() 
	route_cleanup

}



ip_neigh_get_check()

{

	ip neigh help 2>&1 | grep -q 'ip neigh get'

	if [ $? -ne 0 ]; then

		echo "iproute2 command does not support neigh get. Skipping test"

		return 1

	fi



	return 0

}



ipv4_bcast_neigh_test()

{

	local rc



	echo

	echo "IPv4 broadcast neighbour tests"



	ip_neigh_get_check || return 1



	setup



	set -e

	run_cmd "$IP neigh add 192.0.2.111 lladdr 00:11:22:33:44:55 nud perm dev dummy0"

	run_cmd "$IP neigh add 192.0.2.255 lladdr 00:11:22:33:44:55 nud perm dev dummy0"



	run_cmd "$IP neigh get 192.0.2.111 dev dummy0"

	run_cmd "$IP neigh get 192.0.2.255 dev dummy0"



	run_cmd "$IP address add 192.0.2.1/24 broadcast 192.0.2.111 dev dummy0"



	run_cmd "$IP neigh add 203.0.113.111 nud failed dev dummy0"

	run_cmd "$IP neigh add 203.0.113.255 nud failed dev dummy0"



	run_cmd "$IP neigh get 203.0.113.111 dev dummy0"

	run_cmd "$IP neigh get 203.0.113.255 dev dummy0"



	run_cmd "$IP address add 203.0.113.1/24 broadcast 203.0.113.111 dev dummy0"

	set +e



	run_cmd "$IP neigh get 192.0.2.111 dev dummy0"

	log_test $? 0 "Resolved neighbour for broadcast address"



	run_cmd "$IP neigh get 192.0.2.255 dev dummy0"

	log_test $? 0 "Resolved neighbour for network broadcast address"



	run_cmd "$IP neigh get 203.0.113.111 dev dummy0"

	log_test $? 2 "Unresolved neighbour for broadcast address"



	run_cmd "$IP neigh get 203.0.113.255 dev dummy0"

	log_test $? 2 "Unresolved neighbour for network broadcast address"



	cleanup

}



################################################################################

# usage
@@ -2028,6 +2083,7 @@ do 
	ipv4_route_v6_gw)		ipv4_route_v6_gw_test;;

	ipv4_mangle)			ipv4_mangle_test;;

	ipv6_mangle)			ipv6_mangle_test;;

	ipv4_bcast_neigh)		ipv4_bcast_neigh_test;;



	help) echo "Test names: $TESTS"; exit 0;;

	esac