From 390b95a5fb84e7999eedb021382c96d1500e01fc Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Thu, 17 Jun 2021 16:46:15 -0700 Subject: 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: Paolo Abeni Signed-off-by: Paolo Abeni Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/options.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'net/mptcp') diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 8cbc75868969..1aec01686c1a 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -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; -- cgit