diff mbox series

[v4,mptcp-next,11/22] mptcp: receive checksum for MP_CAPABLE with data

Message ID b2717e05d0a33c8a8cb80d0523c76b09b725a260.1619189145.git.pabeni@redhat.com
State Superseded, archived
Delegated to: Mat Martineau
Headers show
Series mptcp: data checksum support | expand

Commit Message

Paolo Abeni April 23, 2021, 2:49 p.m. UTC 
From: Geliang Tang <geliangtang@gmail.com>

This patch added a new member named csum in struct mptcp_options_received.

When parsing the MP_CAPABLE with data, if the checksum is enabled,
adjust the expected_opsize. If the receiving option length matches the
length with the data checksum, get the checksum value and save it in
mp_opt->csum. And in mptcp_incoming_options, pass it to mpext->csum.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/options.c  | 21 ++++++++++++++++-----
 net/mptcp/protocol.h |  1 +
 2 files changed, 17 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 2d6b0158e19b..cd205ad09c00 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -37,10 +37,13 @@  static void mptcp_parse_option(const struct sock *sk,
 	case MPTCPOPT_MP_CAPABLE:
 		/* strict size checking */
 		if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
-			if (skb->len > tcp_hdr(skb)->doff << 2)
+			if (skb->len > tcp_hdr(skb)->doff << 2) {
 				expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA;
-			else
+				if (READ_ONCE(msk->csum_enabled))
+					expected_opsize += TCPOLEN_MPTCP_DSS_CHECKSUM;
+			} else {
 				expected_opsize = TCPOLEN_MPTCP_MPC_ACK;
+			}
 		} else {
 			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)
 				expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK;
@@ -88,7 +91,7 @@  static void mptcp_parse_option(const struct sock *sk,
 			mp_opt->rcvr_key = get_unaligned_be64(ptr);
 			ptr += 8;
 		}
-		if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA) {
+		if (opsize >= TCPOLEN_MPTCP_MPC_ACK_DATA) {
 			/* Section 3.1.:
 			 * "the data parameters in a MP_CAPABLE are semantically
 			 * equivalent to those in a DSS option and can be used
@@ -100,9 +103,13 @@  static void mptcp_parse_option(const struct sock *sk,
 			mp_opt->data_len = get_unaligned_be16(ptr);
 			ptr += 2;
 		}
-		pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d",
+		if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA + TCPOLEN_MPTCP_DSS_CHECKSUM) {
+			mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr);
+			ptr += 2;
+		}
+		pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d csum=%u",
 			 version, flags, opsize, mp_opt->sndr_key,
-			 mp_opt->rcvr_key, mp_opt->data_len);
+			 mp_opt->rcvr_key, mp_opt->data_len, mp_opt->csum);
 		break;
 
 	case MPTCPOPT_MP_JOIN:
@@ -346,6 +353,7 @@  void mptcp_get_options(const struct sock *sk,
 	mp_opt->mp_prio = 0;
 	mp_opt->reset = 0;
 	mp_opt->csum_reqd = 0;
+	mp_opt->csum = 0;
 
 	length = (th->doff * 4) - sizeof(struct tcphdr);
 	ptr = (const unsigned char *)(th + 1);
@@ -1121,6 +1129,9 @@  void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 		}
 		mpext->data_len = mp_opt.data_len;
 		mpext->use_map = 1;
+
+		if (READ_ONCE(msk->csum_enabled))
+			mpext->csum = mp_opt.csum;
 	}
 }
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 51f4bbe1703a..d2b00f8c4040 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -124,6 +124,7 @@  struct mptcp_options_received {
 	u64	data_seq;
 	u32	subflow_seq;
 	u16	data_len;
+	__sum16	csum;
 	u16	mp_capable : 1,
 		mp_join : 1,
 		fastclose : 1,