[PATCH v2 1/1] sctp: do not update t->pathmtu when PMTUD is disabled

[Jacek Szafraniec <jacek.szafraniec@nokia.com>]

>> Transport pathmtu can not be updated, when PMTUD is disabled
>> and pathmtu is condigured as fixed. Unconditional update t->pathmtu
>> will result in overwriting parameter configured by user
>> and lack of GSO usage.
>Seems right, the update of dst's mtu from elsewhere shouldn't
>affect SCTP either if SPP_PMTUD_DISABLE flag is set.
I agree.

>Can you please try to fix it with this?
>
>diff --git a/net/sctp/output.c b/net/sctp/output.c
>index a6aa17d..9f53323 100644
>--- a/net/sctp/output.c
>+++ b/net/sctp/output.c
>@@ -103,8 +103,8 @@ void sctp_packet_config(struct sctp_packet
>*packet, __u32 vtag,
>                sctp_transport_route(tp, NULL, sp);
>                if (asoc->param_flags & SPP_PMTUD_ENABLE)
>                        sctp_assoc_sync_pmtu(asoc);
>-       } else if (!sctp_transport_pmtu_check(tp)) {
>-               if (asoc->param_flags & SPP_PMTUD_ENABLE)
>+       } else if (asoc->param_flags & SPP_PMTUD_ENABLE) {
>+               if (!sctp_transport_pmtu_check(tp))
>                        sctp_assoc_sync_pmtu(asoc);
>        }
This proposal is better.
I've tested above. Result is OK.

Tested-by: Jacek Szafraniec <jacek.szafraniec@nokia.com>

Thanks!