* "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) {
const struct sk_buff *skb,
struct mptcp_options_received *mp_opt)
{
+ struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+ struct mptcp_sock *msk = mptcp_sk(subflow->conn);
const struct tcphdr *th = tcp_hdr(skb);
const unsigned char *ptr;
int length;
mp_opt->dss = 0;
mp_opt->mp_prio = 0;
mp_opt->reset = 0;
+ mp_opt->csum_reqd = READ_ONCE(msk->csum_enabled);
length = (th->doff * 4) - sizeof(struct tcphdr);
ptr = (const unsigned char *)(th + 1);
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;