From: Jakub Sitnicki <jkbs@redhat.com>
To: netdev@vger.kernel.org
Cc: David Miller <davem@davemloft.net>,
Hannes Frederic Sowa <hannes@stressinduktion.org>,
Florian Westphal <fw@strlen.de>
Subject: [PATCH net] ipv6: Don't use ufo handling on later transformed packets
Date: Wed, 26 Oct 2016 11:21:14 +0200 [thread overview]
Message-ID: <1477473674-21702-1-git-send-email-jkbs@redhat.com> (raw)
Similar to commit c146066ab802 ("ipv4: Don't use ufo handling on later
transformed packets"), don't perform UFO on packets that will be IPsec
transformed. To detect it we rely on the fact that headerlen in
dst_entry is non-zero only for transformation bundles (xfrm_dst
objects).
Unwanted segmentation can be observed with a NETIF_F_UFO capable device,
such as a dummy device:
DEV=dum0 LEN=1493
ip li add $DEV type dummy
ip addr add fc00::1/64 dev $DEV nodad
ip link set $DEV up
ip xfrm policy add dir out src fc00::1 dst fc00::2 \
tmpl src fc00::1 dst fc00::2 proto esp spi 1
ip xfrm state add src fc00::1 dst fc00::2 \
proto esp spi 1 enc 'aes' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b
tcpdump -n -nn -i $DEV -t &
socat /dev/zero,readbytes=$LEN udp6:[fc00::2]:$LEN
tcpdump output before:
IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448
IP6 fc00::1 > fc00::2: frag (1448|48)
IP6 fc00::1 > fc00::2: ESP(spi=0x00000001,seq=0x2), length 88
... and after:
IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448
IP6 fc00::1 > fc00::2: frag (1448|80)
Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Signed-off-by: Jakub Sitnicki <jkbs@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
net/ipv6/ip6_output.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 6001e78..59eb4ed 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1366,7 +1366,7 @@ static int __ip6_append_data(struct sock *sk,
if (((length > mtu) ||
(skb && skb_is_gso(skb))) &&
(sk->sk_protocol == IPPROTO_UDP) &&
- (rt->dst.dev->features & NETIF_F_UFO) &&
+ (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len &&
(sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) {
err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
hh_len, fragheaderlen, exthdrlen,
--
2.7.4
next reply other threads:[~2016-10-26 9:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 9:21 Jakub Sitnicki [this message]
2016-10-31 17:12 ` [PATCH net] ipv6: Don't use ufo handling on later transformed packets David Miller
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