From 99e954f4871d9a760451c5ada99dfaae5df256e5 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 28 Oct 2020 21:11:21 +0100 Subject: netns: check that route_me_harder packets use the right sk If netfilter changes the packet mark, the packet is rerouted. The ip_route_me_harder family of functions fails to use the right sk, opting to instead use skb->sk, resulting in a routing loop when used with tunnels. Fixing this inside of the compat layer with skb_orphan would work but would cause other problems, by disabling TSQ, so instead we warn if the calling kernel hasn't yet backported the fix for this. Reported-by: Chen Minqiang Signed-off-by: Jason A. Donenfeld --- src/tests/netns.sh | 9 +++++++++ src/tests/qemu/kernel.config | 2 ++ 2 files changed, 11 insertions(+) diff --git a/src/tests/netns.sh b/src/tests/netns.sh index c83ddc7..ecfe914 100755 --- a/src/tests/netns.sh +++ b/src/tests/netns.sh @@ -30,6 +30,7 @@ netns0="wg-test-$$-0" netns1="wg-test-$$-1" netns2="wg-test-$$-2" pretty() { echo -e "\x1b[32m\x1b[1m[+] ${1:+NS$1: }${2}\x1b[0m" >&3; } +compatwarn() { echo -e "\x1b[31m\x1b[1m[-] Tolerated failure: $1\x1b[0m" >&3; } pp() { pretty "" "$*"; "$@"; } maybe_exec() { if [[ $BASHPID -eq $$ ]]; then "$@"; else exec "$@"; fi; } n0() { pretty 0 "$*"; maybe_exec ip netns exec $netns0 "$@"; } @@ -316,6 +317,14 @@ pp sleep 3 n2 ping -W 1 -c 1 192.168.241.1 n1 wg set wg0 peer "$pub2" persistent-keepalive 0 +# Test that sk_bound_dev_if works +n1 ping -I wg0 -c 1 -W 1 192.168.241.2 +# What about when the mark changes and the packet must be rerouted? +n1 iptables -t mangle -I OUTPUT -j MARK --set-xmark 1 +n1 ping -c 1 -W 1 192.168.241.2 # First the boring case +n1 ping -I wg0 -c 1 -W 1 192.168.241.2 || compatwarn "sk_bound_dev_if test failed, but fix not backportable in compat layer" # Then the sk_bound_dev_if case +n1 iptables -t mangle -D OUTPUT -j MARK --set-xmark 1 + # Test that onion routing works, even when it loops n1 wg set wg0 peer "$pub3" allowed-ips 192.168.242.2/32 endpoint 192.168.241.2:5 ip1 addr add 192.168.242.1/24 dev wg0 diff --git a/src/tests/qemu/kernel.config b/src/tests/qemu/kernel.config index 071a43f..35e9a1b 100644 --- a/src/tests/qemu/kernel.config +++ b/src/tests/qemu/kernel.config @@ -17,10 +17,12 @@ CONFIG_NF_NAT=y CONFIG_NETFILTER_XTABLES=y CONFIG_NETFILTER_XT_NAT=y CONFIG_NETFILTER_XT_MATCH_LENGTH=y +CONFIG_NETFILTER_XT_MARK=y CONFIG_NF_CONNTRACK_IPV4=y CONFIG_NF_NAT_IPV4=y CONFIG_IP_NF_IPTABLES=y CONFIG_IP_NF_FILTER=y +CONFIG_IP_NF_MANGLE=y CONFIG_IP_NF_NAT=y CONFIG_IP_ADVANCED_ROUTER=y CONFIG_IP_MULTIPLE_TABLES=y -- cgit v1.2.3