[PATCH mptcp-next v2 0/2] send MP_FAIL with MP_RST and others

[PATCH mptcp-next v2 0/2] send MP_FAIL with MP_RST and others

[Geliang Tang]

v2:
 - rename patch 1 as a squash-to patch.
 - print out reset_transient in patch 2 too. Please keep patch 2 as a
standalone patch, not a squash-to patch.

Two small patches about sending MP_FAIL with MP_RST.

Geliang Tang (2):
  Squash to "mptcp: implement fastclose xmit path"
  mptcp: print out reset infos of MP_RST

 net/mptcp/options.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

-- 
2.31.1

[PATCH mptcp-next v2 1/2] Squash to "mptcp: implement fastclose xmit path"

[Geliang Tang]

As described in RFC8684, 3.7 Fallback:

'''
Therefore, it is not possible to recover the subflow, and the affected
subflow must be immediately closed with a RST that includes an MP_FAIL
option (Figure 16), which defines the data sequence number at the start
of the segment (defined by the Data Sequence Mapping) that had the
checksum failure.
'''

MP_FAIL could be sent with MP_RST at the same time.

This patch fixed it.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/options.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 8a1020e4285c..dc998a14f4cb 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -829,8 +829,11 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
 
 	if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) {
 		if (mptcp_established_options_fastclose(sk, &opt_size, remaining, opts) ||
-		    mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts) ||
-		    mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) {
+		    mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {
+			*size += opt_size;
+			remaining -= opt_size;
+		}
+		if (mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) {
 			*size += opt_size;
 			remaining -= opt_size;
 		}
-- 
2.31.1

[PATCH mptcp-next v2 2/2] mptcp: print out reset infos of MP_RST

[Geliang Tang]

This patch printed out the reset infos, reset_transient and reset_reason,
of MP_RST in mptcp_parse_option() to show that MP_RST is received.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/options.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index dc998a14f4cb..823a831a699c 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -336,6 +336,8 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		flags = *ptr++;
 		mp_opt->reset_transient = flags & MPTCP_RST_TRANSIENT;
 		mp_opt->reset_reason = *ptr;
+		pr_debug("MP_RST: transient=%u reason=%u",
+			 mp_opt->reset_transient, mp_opt->reset_reason);
 		break;
 
 	case MPTCPOPT_MP_FAIL:
-- 
2.31.1