target/linux/generic/backport-5.4/080-wireguard-0085-wireguard-device-use-icmp_ndo_send-helper.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: "Jason A. Donenfeld" <Jason@zx2c4.com>
   3 Date: Tue, 11 Feb 2020 20:47:08 +0100
   4 Subject: [PATCH] wireguard: device: use icmp_ndo_send helper
   5
   6 commit a12d7f3cbdc72c7625881c8dc2660fc2c979fdf2 upstream.
   7
   8 Because wireguard is calling icmp from network device context, it should
   9 use the ndo helper so that the rate limiting applies correctly.  This
  10 commit adds a small test to the wireguard test suite to ensure that the
  11 new functions continue doing the right thing in the context of
  12 wireguard. It does this by setting up a condition that will definately
  13 evoke an icmp error message from the driver, but along a nat'd path.
  14
  15 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  16 Signed-off-by: David S. Miller <davem@davemloft.net>
  17 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  18 ---
  19  drivers/net/wireguard/device.c             |  4 ++--
  20  tools/testing/selftests/wireguard/netns.sh | 11 +++++++++++
  21  2 files changed, 13 insertions(+), 2 deletions(-)
  22
  23 --- a/drivers/net/wireguard/device.c
  24 +++ b/drivers/net/wireguard/device.c
  25 @@ -203,9 +203,9 @@ err_peer:
  26  err:
  27         ++dev->stats.tx_errors;
  28         if (skb->protocol == htons(ETH_P_IP))
  29 -               icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
  30 +               icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
  31         else if (skb->protocol == htons(ETH_P_IPV6))
  32 -               icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
  33 +               icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
  34         kfree_skb(skb);
  35         return ret;
  36  }
  37 --- a/tools/testing/selftests/wireguard/netns.sh
  38 +++ b/tools/testing/selftests/wireguard/netns.sh
  39 @@ -24,6 +24,7 @@
  40  set -e
  41
  42  exec 3>&1
  43 +export LANG=C
  44  export WG_HIDE_KEYS=never
  45  netns0="wg-test-$$-0"
  46  netns1="wg-test-$$-1"
  47 @@ -297,7 +298,17 @@ ip1 -4 rule add table main suppress_pref
  48  n1 ping -W 1 -c 100 -f 192.168.99.7
  49  n1 ping -W 1 -c 100 -f abab::1111
  50
  51 +# Have ns2 NAT into wg0 packets from ns0, but return an icmp error along the right route.
  52 +n2 iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -d 192.168.241.0/24 -j SNAT --to 192.168.241.2
  53 +n0 iptables -t filter -A INPUT \! -s 10.0.0.0/24 -i vethrs -j DROP # Manual rpfilter just to be explicit.
  54 +n2 bash -c 'printf 1 > /proc/sys/net/ipv4/ip_forward'
  55 +ip0 -4 route add 192.168.241.1 via 10.0.0.100
  56 +n2 wg set wg0 peer "$pub1" remove
  57 +[[ $(! n0 ping -W 1 -c 1 192.168.241.1 || false) == *"From 10.0.0.100 icmp_seq=1 Destination Host Unreachable"* ]]
  58 +
  59  n0 iptables -t nat -F
  60 +n0 iptables -t filter -F
  61 +n2 iptables -t nat -F
  62  ip0 link del vethrc
  63  ip0 link del vethrs
  64  ip1 link del wg0