diff mbox series

[v3,mptcp-next,13/21] mptcp: receive checksum for DSS

Message ID 5405aeac5e0a44dececbca0d01c65a9ca0fc300e.1619035356.git.pabeni@redhat.com
State Superseded, archived
Delegated to: Paolo Abeni
Headers show
Series mptcp: data checksum support | expand

Commit Message

Paolo Abeni April 21, 2021, 8:18 p.m. UTC 
From: Geliang Tang <geliangtang@gmail.com>

In mptcp_parse_option, adjust the expected_opsize, and parse the data
checksum value from the receiving DSS, then save it in mp_opt->csum.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/options.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 83a981684bbf..43e454c14160 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -166,6 +166,7 @@  static void mptcp_parse_option(const struct sock *sk,
 		mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0;
 		mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0;
 		mp_opt->use_ack = (flags & MPTCP_DSS_HAS_ACK);
+		mp_opt->csum_reqd = READ_ONCE(msk->csum_enabled);
 
 		pr_debug("data_fin=%d dsn64=%d use_map=%d ack64=%d use_ack=%d",
 			 mp_opt->data_fin, mp_opt->dsn64,
@@ -186,6 +187,9 @@  static void mptcp_parse_option(const struct sock *sk,
 				expected_opsize += TCPOLEN_MPTCP_DSS_MAP64;
 			else
 				expected_opsize += TCPOLEN_MPTCP_DSS_MAP32;
+
+			if (mp_opt->csum_reqd)
+				expected_opsize += TCPOLEN_MPTCP_DSS_CHECKSUM;
 		}
 
 		/* RFC 6824, Section 3.3:
@@ -193,8 +197,7 @@  static void mptcp_parse_option(const struct sock *sk,
 		 * not been negotiated in the MP_CAPABLE handshake,
 		 * the checksum field MUST be ignored.
 		 */
-		if (opsize != expected_opsize &&
-		    opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM)
+		if (opsize != expected_opsize)
 			break;
 
 		mp_opt->dss = 1;
@@ -226,9 +229,14 @@  static void mptcp_parse_option(const struct sock *sk,
 			mp_opt->data_len = get_unaligned_be16(ptr);
 			ptr += 2;
 
-			pr_debug("data_seq=%llu subflow_seq=%u data_len=%u",
+			if (mp_opt->csum_reqd) {
+				mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);
+				ptr += 2;
+			}
+
+			pr_debug("data_seq=%llu subflow_seq=%u data_len=%u csum=%u",
 				 mp_opt->data_seq, mp_opt->subflow_seq,
-				 mp_opt->data_len);
+				 mp_opt->data_len, mp_opt->csum);
 		}
 
 		break;