Commit 04fac2ca authored by Matthieu Baerts's avatar Matthieu Baerts Committed by David S. Miller
Browse files

mptcp: fix opt size when sending DSS + MP_FAIL 



When these two options had to be sent -- which is not common -- the DSS
size was not being taken into account in the remaining size.

Additionally in this situation, the reported size was only the one of
the MP_FAIL which can cause issue if at the end, we need to write more
in the TCP options than previously said.

Here we use a dedicated variable for MP_FAIL size to keep the
WARN_ON_ONCE() just after.

Fixes: c25aeb4e ("mptcp: MP_FAIL suboption sending")
Acked-and-tested-by: default avatarGeliang Tang <geliang.tang@suse.com>
Signed-off-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 14676c04

net/mptcp/options.c

+6 −3
Original line number Diff line number Diff line
@@ -821,10 +821,13 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 
	if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts))

		ret = true;

	else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts)) {

		unsigned int mp_fail_size;



		ret = true;

		if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {

			*size += opt_size;

			remaining -= opt_size;

		if (mptcp_established_options_mp_fail(sk, &mp_fail_size,

						      remaining - opt_size, opts)) {

			*size += opt_size + mp_fail_size;

			remaining -= opt_size - mp_fail_size;

			return true;

		}

	}