target/linux/generic/backport-5.4/080-wireguard-0116-wireguard-selftests-check-that-route_me_harder-packe.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
   3 Date: Thu, 29 Oct 2020 03:56:05 +0100
   4 Subject: [PATCH] wireguard: selftests: check that route_me_harder packets use
   5  the right sk
   6
   7 commit af8afcf1fdd5f365f70e2386c2d8c7a1abd853d7 upstream.
   8
   9 If netfilter changes the packet mark, the packet is rerouted. The
  10 ip_route_me_harder family of functions fails to use the right sk, opting
  11 to instead use skb->sk, resulting in a routing loop when used with
  12 tunnels. With the next change fixing this issue in netfilter, test for
  13 the relevant condition inside our test suite, since wireguard was where
  14 the bug was discovered.
  15
  16 Reported-by: Chen Minqiang <ptpt52@gmail.com>
  17 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  18 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
  19 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  20 ---
  21  tools/testing/selftests/wireguard/netns.sh           | 8 ++++++++
  22  tools/testing/selftests/wireguard/qemu/kernel.config | 2 ++
  23  2 files changed, 10 insertions(+)
  24
  25 --- a/tools/testing/selftests/wireguard/netns.sh
  26 +++ b/tools/testing/selftests/wireguard/netns.sh
  27 @@ -316,6 +316,14 @@ pp sleep 3
  28  n2 ping -W 1 -c 1 192.168.241.1
  29  n1 wg set wg0 peer "$pub2" persistent-keepalive 0
  30
  31 +# Test that sk_bound_dev_if works
  32 +n1 ping -I wg0 -c 1 -W 1 192.168.241.2
  33 +# What about when the mark changes and the packet must be rerouted?
  34 +n1 iptables -t mangle -I OUTPUT -j MARK --set-xmark 1
  35 +n1 ping -c 1 -W 1 192.168.241.2 # First the boring case
  36 +n1 ping -I wg0 -c 1 -W 1 192.168.241.2 # Then the sk_bound_dev_if case
  37 +n1 iptables -t mangle -D OUTPUT -j MARK --set-xmark 1
  38 +
  39  # Test that onion routing works, even when it loops
  40  n1 wg set wg0 peer "$pub3" allowed-ips 192.168.242.2/32 endpoint 192.168.241.2:5
  41  ip1 addr add 192.168.242.1/24 dev wg0
  42 --- a/tools/testing/selftests/wireguard/qemu/kernel.config
  43 +++ b/tools/testing/selftests/wireguard/qemu/kernel.config
  44 @@ -18,10 +18,12 @@ CONFIG_NF_NAT=y
  45  CONFIG_NETFILTER_XTABLES=y
  46  CONFIG_NETFILTER_XT_NAT=y
  47  CONFIG_NETFILTER_XT_MATCH_LENGTH=y
  48 +CONFIG_NETFILTER_XT_MARK=y
  49  CONFIG_NF_CONNTRACK_IPV4=y
  50  CONFIG_NF_NAT_IPV4=y
  51  CONFIG_IP_NF_IPTABLES=y
  52  CONFIG_IP_NF_FILTER=y
  53 +CONFIG_IP_NF_MANGLE=y
  54  CONFIG_IP_NF_NAT=y
  55  CONFIG_IP_ADVANCED_ROUTER=y
  56  CONFIG_IP_MULTIPLE_TABLES=y