@@ -681,6 +681,31 @@ static bool mptcp_established_options_rm_addr(struct sock *sk,
return true;
}
+static bool mptcp_fastclose(const struct mptcp_sock *msk)
+{
+ return READ_ONCE(msk->snd_fastclose);
+}
+
+static bool mptcp_established_options_fastclose(struct sock *sk,
+ unsigned int *size,
+ unsigned int remaining,
+ struct mptcp_out_options *opts)
+{
+ const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+
+ if (likely(!mptcp_fastclose(mptcp_sk(subflow->conn))))
+ return false;
+
+ if (remaining < TCPOLEN_MPTCP_FASTCLOSE)
+ return false;
+
+ *size = TCPOLEN_MPTCP_FASTCLOSE;
+ opts->suboptions |= OPTION_MPTCP_FASTCLOSE;
+ opts->rcvr_key = subflow->remote_key;
+
+ return true;
+}
+
static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,
unsigned int *size,
unsigned int remaining,
@@ -691,6 +716,9 @@ static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_bu
if (remaining < TCPOLEN_MPTCP_RST)
return;
+ if (mptcp_established_options_fastclose(sk, size, remaining, opts))
+ return;
+
*size = TCPOLEN_MPTCP_RST;
opts->suboptions |= OPTION_MPTCP_RST;
opts->reset_transient = subflow->reset_transient;
@@ -1179,6 +1207,13 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
ptr += 5;
}
+ if (OPTION_MPTCP_FASTCLOSE & opts->suboptions) {
+ *ptr++ = mptcp_option(MPTCPOPT_MP_FASTCLOSE,
+ TCPOLEN_MPTCP_FASTCLOSE, 0, 0);
+ put_unaligned_be64(opts->rcvr_key, ptr);
+ ptr += 2;
+ }
+
if (OPTION_MPTCP_RST & opts->suboptions)
*ptr++ = mptcp_option(MPTCPOPT_RST,
TCPOLEN_MPTCP_RST,
@@ -2133,6 +2133,29 @@ static void __mptcp_check_send_data_fin(struct sock *sk)
}
}
+static void __mptcp_send_fastclose(struct sock *sk)
+{
+ struct mptcp_subflow_context *subflow, *tmp;
+ struct mptcp_sock *msk = mptcp_sk(sk);
+
+ WRITE_ONCE(msk->snd_fastclose, true);
+
+ __mptcp_flush_join_list(msk);
+ __mptcp_clear_xmit(sk);
+
+ WRITE_ONCE(msk->snd_nxt, msk->write_seq);
+
+ list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
+ struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow);
+
+ lock_sock(tcp_sk);
+ subflow->reset_transient = 0;
+ subflow->reset_reason = MPTCP_RST_EMPTCP;
+ mptcp_subflow_reset(tcp_sk);
+ release_sock(tcp_sk);
+ }
+}
+
static void __mptcp_wr_shutdown(struct sock *sk)
{
struct mptcp_sock *msk = mptcp_sk(sk);
@@ -2185,6 +2208,7 @@ static void mptcp_close(struct sock *sk, long timeout)
{
struct mptcp_subflow_context *subflow;
bool do_cancel_work = false;
+ bool send_fin = false;
lock_sock(sk);
sk->sk_shutdown = SHUTDOWN_MASK;
@@ -2197,7 +2221,13 @@ static void mptcp_close(struct sock *sk, long timeout)
goto cleanup;
}
- if (mptcp_close_state(sk))
+ send_fin = mptcp_close_state(sk);
+ if (!skb_queue_empty(&sk->sk_receive_queue)) {
+ __mptcp_send_fastclose(sk);
+ send_fin = false;
+ }
+
+ if (send_fin)
__mptcp_wr_shutdown(sk);
sk_stream_wait_close(sk, timeout);
@@ -243,6 +243,7 @@ struct mptcp_sock {
bool fully_established;
bool rcv_data_fin;
bool snd_data_fin_enable;
+ bool snd_fastclose;
bool rcv_fastclose;
bool use_64bit_ack; /* Set when we received a 64-bit DSN */
spinlock_t join_list_lock;
Add building & sending of FASTCLOSE option. RFC 8684 describes two methods: A): Host sends an ACK containing the MP_FASTCLOSE option on one subflow [..] On all the other subflows, Host A sends a regular TCP RST to close these subflows and tears them down. [..] R): Host A sends a RST containing the MP_FASTCLOSE option on all subflows [..]. Host A can tear down the subflows and the connection immediately. This implements option R) only: All subflows are re-set with FASTCLOSE. Signed-off-by: Florian Westphal <fw@strlen.de> --- net/mptcp/options.c | 35 +++++++++++++++++++++++++++++++++++ net/mptcp/protocol.c | 32 +++++++++++++++++++++++++++++++- net/mptcp/protocol.h | 1 + 3 files changed, 67 insertions(+), 1 deletion(-)