Commit 68fe503c authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'ipmr-always-call-ip-6-_mr_forward-from-rcu-read-side-critical-section' 

Ido Schimmel says:

====================
ipmr: Always call ip{,6}_mr_forward() from RCU read-side critical section

Patch #1 fixes a bug in ipmr code.

Patch #2 adds corresponding test cases.
====================

Link: https://lore.kernel.org/r/20220914075339.4074096-1-idosch@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents cf412ec3 2b5a8c8f

net/ipv4/ipmr.c

+2 −0
Original line number Diff line number Diff line
@@ -1004,7 +1004,9 @@ static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt, 


			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);

		} else {

			rcu_read_lock();

			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);

			rcu_read_unlock();

		}

	}

}

net/ipv6/ip6mr.c

+4 −1
Original line number Diff line number Diff line
@@ -1028,8 +1028,11 @@ static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt, 
				((struct nlmsgerr *)nlmsg_data(nlh))->error = -EMSGSIZE;

			}

			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);

		} else

		} else {

			rcu_read_lock();

			ip6_mr_forward(net, mrt, skb->dev, skb, c);

			rcu_read_unlock();

		}

	}

}

tools/testing/selftests/net/forwarding/router_multicast.sh

+91 −1
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ 
# +------------------+       +------------------+

#



ALL_TESTS="mcast_v4 mcast_v6 rpf_v4 rpf_v6"

ALL_TESTS="mcast_v4 mcast_v6 rpf_v4 rpf_v6 unres_v4 unres_v6"

NUM_NETIFS=6

source lib.sh

source tc_common.sh
@@ -406,6 +406,96 @@ rpf_v6() 
	log_test "RPF IPv6"

}



unres_v4()

{

	# Send a multicast packet not corresponding to an installed route,

	# causing the kernel to queue the packet for resolution and emit an

	# IGMPMSG_NOCACHE notification. smcrouted will react to this

	# notification by consulting its (*, G) list and installing an (S, G)

	# route, which will be used to forward the queued packet.



	RET=0



	tc filter add dev $h2 ingress protocol ip pref 1 handle 1 flower \

		dst_ip 225.1.2.3 ip_proto udp dst_port 12345 action drop

	tc filter add dev $h3 ingress protocol ip pref 1 handle 1 flower \

		dst_ip 225.1.2.3 ip_proto udp dst_port 12345 action drop



	# Forwarding should fail before installing a matching (*, G).

	$MZ $h1 -c 1 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \

		-a 00:11:22:33:44:55 -b 01:00:5e:01:02:03 \

		-A 198.51.100.2 -B 225.1.2.3 -q



	tc_check_packets "dev $h2 ingress" 1 0

	check_err $? "Multicast received on first host when should not"

	tc_check_packets "dev $h3 ingress" 1 0

	check_err $? "Multicast received on second host when should not"



	# Create (*, G). Will not be installed in the kernel.

	create_mcast_sg $rp1 0.0.0.0 225.1.2.3 $rp2 $rp3



	$MZ $h1 -c 1 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \

		-a 00:11:22:33:44:55 -b 01:00:5e:01:02:03 \

		-A 198.51.100.2 -B 225.1.2.3 -q



	tc_check_packets "dev $h2 ingress" 1 1

	check_err $? "Multicast not received on first host"

	tc_check_packets "dev $h3 ingress" 1 1

	check_err $? "Multicast not received on second host"



	delete_mcast_sg $rp1 0.0.0.0 225.1.2.3 $rp2 $rp3



	tc filter del dev $h3 ingress protocol ip pref 1 handle 1 flower

	tc filter del dev $h2 ingress protocol ip pref 1 handle 1 flower



	log_test "Unresolved queue IPv4"

}



unres_v6()

{

	# Send a multicast packet not corresponding to an installed route,

	# causing the kernel to queue the packet for resolution and emit an

	# MRT6MSG_NOCACHE notification. smcrouted will react to this

	# notification by consulting its (*, G) list and installing an (S, G)

	# route, which will be used to forward the queued packet.



	RET=0



	tc filter add dev $h2 ingress protocol ipv6 pref 1 handle 1 flower \

		dst_ip ff0e::3 ip_proto udp dst_port 12345 action drop

	tc filter add dev $h3 ingress protocol ipv6 pref 1 handle 1 flower \

		dst_ip ff0e::3 ip_proto udp dst_port 12345 action drop



	# Forwarding should fail before installing a matching (*, G).

	$MZ $h1 -6 -c 1 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \

		-a 00:11:22:33:44:55 -b 33:33:00:00:00:03 \

		-A 2001:db8:1::2 -B ff0e::3 -q



	tc_check_packets "dev $h2 ingress" 1 0

	check_err $? "Multicast received on first host when should not"

	tc_check_packets "dev $h3 ingress" 1 0

	check_err $? "Multicast received on second host when should not"



	# Create (*, G). Will not be installed in the kernel.

	create_mcast_sg $rp1 :: ff0e::3 $rp2 $rp3



	$MZ $h1 -6 -c 1 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \

		-a 00:11:22:33:44:55 -b 33:33:00:00:00:03 \

		-A 2001:db8:1::2 -B ff0e::3 -q



	tc_check_packets "dev $h2 ingress" 1 1

	check_err $? "Multicast not received on first host"

	tc_check_packets "dev $h3 ingress" 1 1

	check_err $? "Multicast not received on second host"



	delete_mcast_sg $rp1 :: ff0e::3 $rp2 $rp3



	tc filter del dev $h3 ingress protocol ipv6 pref 1 handle 1 flower

	tc filter del dev $h2 ingress protocol ipv6 pref 1 handle 1 flower



	log_test "Unresolved queue IPv6"

}



trap cleanup EXIT



setup_prepare