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 <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Geliang Tang 2021-06-17 16:46:15 -07:00 committed by David S. Miller
parent 208e8f6692
commit 390b95a5fb
1 changed files with 10 additions and 6 deletions

View File

@ -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;