Commit 390b95a5 authored by Geliang Tang's avatar Geliang Tang Committed by David S. Miller
Browse files

mptcp: receive checksum for DSS 



In mptcp_parse_option, adjust the expected_opsize, and always parse the
data checksum value from the receiving DSS regardless of csum presence.
Then save it in mp_opt->csum.

Co-developed-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarGeliang Tang <geliangtang@gmail.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 208e8f66

net/mptcp/options.c

+10 −6
Original line number Diff line number Diff line
@@ -182,10 +182,8 @@ static void mptcp_parse_option(const struct sk_buff *skb, 
				expected_opsize += TCPOLEN_MPTCP_DSS_MAP32;

		}



		/* RFC 6824, Section 3.3:

		 * If a checksum is present, but its use had

		 * not been negotiated in the MP_CAPABLE handshake,

		 * the checksum field MUST be ignored.

		/* Always parse any csum presence combination, we will enforce

		 * RFC 8684 Section 3.3.0 checks later in subflow_data_ready

		 */

		if (opsize != expected_opsize &&

		    opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM)
@@ -220,9 +218,15 @@ static void mptcp_parse_option(const struct sk_buff *skb, 
			mp_opt->data_len = get_unaligned_be16(ptr);

			ptr += 2;



			pr_debug("data_seq=%llu subflow_seq=%u data_len=%u",

			if (opsize == expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) {

				mp_opt->csum_reqd = 1;

				mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);

				ptr += 2;

			}



			pr_debug("data_seq=%llu subflow_seq=%u data_len=%u csum=%d:%u",

				 mp_opt->data_seq, mp_opt->subflow_seq,

				 mp_opt->data_len);

				 mp_opt->data_len, mp_opt->csum_reqd, mp_opt->csum);

		}



		break;