@@ -71,11 +71,9 @@ static void mptcp_parse_option(const struct sk_buff *skb,
* "If a checksum is not present when its use has been
* negotiated, the receiver MUST close the subflow with a RST as
* it is considered broken."
- *
- * We don't implement DSS checksum - fall back to TCP.
*/
if (flags & MPTCP_CAP_CHECKSUM_REQD)
- break;
+ mp_opt->csum_reqd = 1;
mp_opt->mp_capable = 1;
if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) {
@@ -342,6 +340,7 @@ void mptcp_get_options(const struct sk_buff *skb,
mp_opt->dss = 0;
mp_opt->mp_prio = 0;
mp_opt->reset = 0;
+ mp_opt->csum_reqd = 0;
length = (th->doff * 4) - sizeof(struct tcphdr);
ptr = (const unsigned char *)(th + 1);
@@ -2718,6 +2718,8 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
msk->token = subflow_req->token;
msk->subflow = NULL;
WRITE_ONCE(msk->fully_established, false);
+ if (mp_opt->csum_reqd)
+ WRITE_ONCE(msk->csum_enabled, true);
msk->write_seq = subflow_req->idsn + 1;
msk->snd_nxt = msk->write_seq;
@@ -132,6 +132,7 @@ struct mptcp_options_received {
rm_addr : 1,
mp_prio : 1,
echo : 1,
+ csum_reqd : 1,
backup : 1;
u32 token;
u32 nonce;
@@ -405,6 +405,8 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
goto fallback;
}
+ if (mp_opt.csum_reqd)
+ WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true);
subflow->mp_capable = 1;
subflow->can_ack = 1;
subflow->remote_key = mp_opt.sndr_key;
This patch added a new flag csum_reqd in struct mptcp_options_received, if the flag MPTCP_CAP_CHECKSUM_REQD is set in the receiving MP_CAPABLE suboption, set this flag. In mptcp_sk_clone and subflow_finish_connect, if the flag csum_reqd is set, set the flag msk->csum_enabled to true. Signed-off-by: Geliang Tang <geliangtang@gmail.com> --- net/mptcp/options.c | 5 ++--- net/mptcp/protocol.c | 2 ++ net/mptcp/protocol.h | 1 + net/mptcp/subflow.c | 2 ++ 4 files changed, 7 insertions(+), 3 deletions(-)