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| author | Sabrina Dubroca <sd@queasysnail.net> | 2021-04-16 11:27:59 +0200 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2021-04-19 12:43:50 +0200 |
| commit | b515d2637276a3810d6595e10ab02c13bfd0b63a (patch) | |
| tree | 9f132792fbba478353990706ff4142bf6dc8a58b /include/net | |
| parent | Merge tag 'net-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/net... (diff) | |
| download | linux-b515d2637276a3810d6595e10ab02c13bfd0b63a.tar.xz linux-b515d2637276a3810d6595e10ab02c13bfd0b63a.zip | |
xfrm: xfrm_state_mtu should return at least 1280 for ipv6
Jianwen reported that IPv6 Interoperability tests are failing in an
IPsec case where one of the links between the IPsec peers has an MTU
of 1280. The peer generates a packet larger than this MTU, the router
replies with a "Packet too big" message indicating an MTU of 1280.
When the peer tries to send another large packet, xfrm_state_mtu
returns 1280 - ipsec_overhead, which causes ip6_setup_cork to fail
with EINVAL.
We can fix this by forcing xfrm_state_mtu to return IPV6_MIN_MTU when
IPv6 is used. After going through IPsec, the packet will then be
fragmented to obey the actual network's PMTU, just before leaving the
host.
Currently, TFC padding is capped to PMTU - overhead to avoid
fragementation: after padding and encapsulation, we still fit within
the PMTU. That behavior is preserved in this patch.
Fixes: 91657eafb64b ("xfrm: take net hdr len into account for esp payload size calculation")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/xfrm.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/xfrm.h b/include/net/xfrm.h index c58a6d4eb610..6232a5f048bd 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1546,6 +1546,7 @@ void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si); void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si); u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq); int xfrm_init_replay(struct xfrm_state *x); +u32 __xfrm_state_mtu(struct xfrm_state *x, int mtu); u32 xfrm_state_mtu(struct xfrm_state *x, int mtu); int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload); int xfrm_init_state(struct xfrm_state *x); |