mptcp: track accurately the incoming MPC suboption type

Currently in the receive path we don't need to discriminate
between MPC SYN, MPC SYN-ACK and MPC ACK, but soon the fastopen
code will need that info to properly track the fully established
status.

Track the exact MPC suboption type into the receive opt bitmap.
No functional change intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 30d289044e71b17c4d4866b643b60290fc4bde1c..784a205e80dab0352dfaa18c83033ff7f5c27107 100644 (file)
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -26,6 +26,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 {
        u8 subtype = *ptr >> 4;
        int expected_opsize;
+       u16 subopt;
        u8 version;
        u8 flags;
        u8 i;
@@ -38,11 +39,15 @@ static void mptcp_parse_option(const struct sk_buff *skb,
                                expected_opsize = TCPOLEN_MPTCP_MPC_ACK_DATA;
                        else
                                expected_opsize = TCPOLEN_MPTCP_MPC_ACK;
+                       subopt = OPTION_MPTCP_MPC_ACK;
                } else {
-                       if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)
+                       if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK) {
                                expected_opsize = TCPOLEN_MPTCP_MPC_SYNACK;
-                       else
+                               subopt = OPTION_MPTCP_MPC_SYNACK;
+                       } else {
                                expected_opsize = TCPOLEN_MPTCP_MPC_SYN;
+                               subopt = OPTION_MPTCP_MPC_SYN;
+                       }
                }
 
                /* Cfr RFC 8684 Section 3.3.0:
@@ -85,7 +90,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 
                mp_opt->deny_join_id0 = !!(flags & MPTCP_CAP_DENY_JOIN_ID0);
 
-               mp_opt->suboptions |= OPTIONS_MPTCP_MPC;
+               mp_opt->suboptions |= subopt;
                if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) {
                        mp_opt->sndr_key = get_unaligned_be64(ptr);
                        ptr += 8;