Searched hist:"6596 a0229541270fb8d38d989f91b78838e5e9da" (Results 1 – 5 of 5) sorted by relevance
| /openbmc/linux/net/ipv4/ |
| H A D | esp4.c | diff a6d95c5a628a09be129f25d5663a7e9db8261f51 Wed Jan 26 09:00:18 CST 2022 Jiri Bohac <jbohac@suse.cz> Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6"
This reverts commit b515d2637276a3810d6595e10ab02c13bfd0b63a.
Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu
should return at least 1280 for ipv6") in v5.14 breaks the TCP MSS
calculation in ipsec transport mode, resulting complete stalls of TCP
connections. This happens when the (P)MTU is 1280 or slighly larger.
The desired formula for the MSS is:
MSS = (MTU - ESP_overhead) - IP header - TCP header
However, the above commit clamps the (MTU - ESP_overhead) to a
minimum of 1280, turning the formula into
MSS = max(MTU - ESP overhead, 1280) - IP header - TCP header
With the (P)MTU near 1280, the calculated MSS is too large and the
resulting TCP packets never make it to the destination because they
are over the actual PMTU.
The above commit also causes suboptimal double fragmentation in
xfrm tunnel mode, as described in
https://lore.kernel.org/netdev/20210429202529.codhwpc7w6kbudug@dwarf.suse.cz/
The original problem the above commit was trying to fix is now fixed
by commit 6596a0229541270fb8d38d989f91b78838e5e9da ("xfrm: fix MTU
regression").
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|
| /openbmc/linux/net/ipv6/ |
| H A D | esp6.c | diff a6d95c5a628a09be129f25d5663a7e9db8261f51 Wed Jan 26 09:00:18 CST 2022 Jiri Bohac <jbohac@suse.cz> Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6"
This reverts commit b515d2637276a3810d6595e10ab02c13bfd0b63a.
Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu
should return at least 1280 for ipv6") in v5.14 breaks the TCP MSS
calculation in ipsec transport mode, resulting complete stalls of TCP
connections. This happens when the (P)MTU is 1280 or slighly larger.
The desired formula for the MSS is:
MSS = (MTU - ESP_overhead) - IP header - TCP header
However, the above commit clamps the (MTU - ESP_overhead) to a
minimum of 1280, turning the formula into
MSS = max(MTU - ESP overhead, 1280) - IP header - TCP header
With the (P)MTU near 1280, the calculated MSS is too large and the
resulting TCP packets never make it to the destination because they
are over the actual PMTU.
The above commit also causes suboptimal double fragmentation in
xfrm tunnel mode, as described in
https://lore.kernel.org/netdev/20210429202529.codhwpc7w6kbudug@dwarf.suse.cz/
The original problem the above commit was trying to fix is now fixed
by commit 6596a0229541270fb8d38d989f91b78838e5e9da ("xfrm: fix MTU
regression").
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|
| H A D | ip6_output.c | diff 6596a0229541270fb8d38d989f91b78838e5e9da Wed Jan 19 03:22:53 CST 2022 Jiri Bohac <jbohac@suse.cz> xfrm: fix MTU regression
Commit 749439bfac6e1a2932c582e2699f91d329658196 ("ipv6: fix udpv6
sendmsg crash caused by too small MTU") breaks PMTU for xfrm.
A Packet Too Big ICMPv6 message received in response to an ESP
packet will prevent all further communication through the tunnel
if the reported MTU minus the ESP overhead is smaller than 1280.
E.g. in a case of a tunnel-mode ESP with sha256/aes the overhead
is 92 bytes. Receiving a PTB with MTU of 1371 or less will result
in all further packets in the tunnel dropped. A ping through the
tunnel fails with "ping: sendmsg: Invalid argument".
Apparently the MTU on the xfrm route is smaller than 1280 and
fails the check inside ip6_setup_cork() added by 749439bf.
We found this by debugging USGv6/ipv6ready failures. Failing
tests are: "Phase-2 Interoperability Test Scenario IPsec" /
5.3.11 and 5.4.11 (Tunnel Mode: Fragmentation).
Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm:
xfrm_state_mtu should return at least 1280 for ipv6") attempted
to fix this but caused another regression in TCP MSS calculations
and had to be reverted.
The patch below fixes the situation by dropping the MTU
check and instead checking for the underflows described in the
749439bf commit message.
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Fixes: 749439bfac6e ("ipv6: fix udpv6 sendmsg crash caused by too small MTU")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|
| /openbmc/linux/net/xfrm/ |
| H A D | xfrm_state.c | diff a6d95c5a628a09be129f25d5663a7e9db8261f51 Wed Jan 26 09:00:18 CST 2022 Jiri Bohac <jbohac@suse.cz> Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6"
This reverts commit b515d2637276a3810d6595e10ab02c13bfd0b63a.
Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu
should return at least 1280 for ipv6") in v5.14 breaks the TCP MSS
calculation in ipsec transport mode, resulting complete stalls of TCP
connections. This happens when the (P)MTU is 1280 or slighly larger.
The desired formula for the MSS is:
MSS = (MTU - ESP_overhead) - IP header - TCP header
However, the above commit clamps the (MTU - ESP_overhead) to a
minimum of 1280, turning the formula into
MSS = max(MTU - ESP overhead, 1280) - IP header - TCP header
With the (P)MTU near 1280, the calculated MSS is too large and the
resulting TCP packets never make it to the destination because they
are over the actual PMTU.
The above commit also causes suboptimal double fragmentation in
xfrm tunnel mode, as described in
https://lore.kernel.org/netdev/20210429202529.codhwpc7w6kbudug@dwarf.suse.cz/
The original problem the above commit was trying to fix is now fixed
by commit 6596a0229541270fb8d38d989f91b78838e5e9da ("xfrm: fix MTU
regression").
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|
| /openbmc/linux/include/net/ |
| H A D | xfrm.h | diff a6d95c5a628a09be129f25d5663a7e9db8261f51 Wed Jan 26 09:00:18 CST 2022 Jiri Bohac <jbohac@suse.cz> Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6"
This reverts commit b515d2637276a3810d6595e10ab02c13bfd0b63a.
Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu
should return at least 1280 for ipv6") in v5.14 breaks the TCP MSS
calculation in ipsec transport mode, resulting complete stalls of TCP
connections. This happens when the (P)MTU is 1280 or slighly larger.
The desired formula for the MSS is:
MSS = (MTU - ESP_overhead) - IP header - TCP header
However, the above commit clamps the (MTU - ESP_overhead) to a
minimum of 1280, turning the formula into
MSS = max(MTU - ESP overhead, 1280) - IP header - TCP header
With the (P)MTU near 1280, the calculated MSS is too large and the
resulting TCP packets never make it to the destination because they
are over the actual PMTU.
The above commit also causes suboptimal double fragmentation in
xfrm tunnel mode, as described in
https://lore.kernel.org/netdev/20210429202529.codhwpc7w6kbudug@dwarf.suse.cz/
The original problem the above commit was trying to fix is now fixed
by commit 6596a0229541270fb8d38d989f91b78838e5e9da ("xfrm: fix MTU
regression").
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|