linux/net/xfrm
Sabrina Dubroca b515d26372 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: 91657eafb6 ("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>
2021-04-19 12:43:50 +02:00
..
espintcp.c espintcp: restore IP CB before handing the packet to xfrm 2020-08-17 15:58:04 +02:00
Kconfig xfrm/compat: Add 32=>64-bit messages translator 2020-09-24 08:53:03 +02:00
Makefile xfrm: Provide API to register translator module 2020-09-24 08:53:03 +02:00
xfrm_algo.c crypto: skcipher - remove the "blkcipher" algorithm type 2019-11-01 13:38:32 +08:00
xfrm_compat.c xfrm/compat: Cleanup WARN()s that can be user-triggered 2021-03-30 07:29:09 +02:00
xfrm_device.c xfrm: Provide private skb extensions for segmented and hw offloaded ESP packets 2021-03-29 09:14:12 +02:00
xfrm_hash.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
xfrm_hash.h xfrm: use complete IPv6 addresses for hash 2018-10-15 10:09:18 +02:00
xfrm_inout.h xfrm: move xfrm4_extract_header to common helper 2020-05-06 09:40:08 +02:00
xfrm_input.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2021-01-21 11:05:10 -08:00
xfrm_interface.c xfrm: interface: fix ipv4 pmtu check to honor ip header df 2021-02-23 18:23:58 +01:00
xfrm_ipcomp.c net: Use skb_frag_off accessors 2019-07-30 14:21:32 -07:00
xfrm_output.c xfrm: BEET mode doesn't support fragments for inner packets 2021-03-24 09:58:19 +01:00
xfrm_policy.c xfrm: Fix wraparound in xfrm_policy_addr_delta() 2021-01-04 10:35:09 +01:00
xfrm_proc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm_replay.c xfrm: introduce oseq-may-wrap flag 2020-06-24 07:51:01 +02:00
xfrm_state.c xfrm: xfrm_state_mtu should return at least 1280 for ipv6 2021-04-19 12:43:50 +02:00
xfrm_sysctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm_user.c xfrm: Return the correct errno code 2021-02-04 09:29:27 +01:00