1 files changed, 70 insertions, 33 deletions

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index a4f3c27f0309..c34ecadee120 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -157,8 +157,8 @@ static int subflow_check_req(struct request_sock *req,
 
 	mptcp_get_options(skb, &mp_opt);
 
-	opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC);
-	opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ);
+	opt_mp_capable = !!(mp_opt.suboptions & OPTION_MPTCP_MPC_SYN);
+	opt_mp_join = !!(mp_opt.suboptions & OPTION_MPTCP_MPJ_SYN);
 	if (opt_mp_capable) {
 		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE);
 
@@ -254,8 +254,8 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req,
 	subflow_init_req(req, sk_listener);
 	mptcp_get_options(skb, &mp_opt);
 
-	opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC);
-	opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ);
+	opt_mp_capable = !!(mp_opt.suboptions & OPTION_MPTCP_MPC_ACK);
+	opt_mp_join = !!(mp_opt.suboptions & OPTION_MPTCP_MPJ_ACK);
 	if (opt_mp_capable && opt_mp_join)
 		return -EINVAL;
 
@@ -419,25 +419,28 @@ static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct soc
 	return inet_sk(sk)->inet_dport != inet_sk((struct sock *)msk)->inet_dport;
 }
 
-void __mptcp_set_connected(struct sock *sk)
+void __mptcp_sync_state(struct sock *sk, int state)
 {
-	__mptcp_propagate_sndbuf(sk, mptcp_sk(sk)->first);
+	struct mptcp_subflow_context *subflow;
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	struct sock *ssk = msk->first;
+
+	subflow = mptcp_subflow_ctx(ssk);
+	__mptcp_propagate_sndbuf(sk, ssk);
+	if (!msk->rcvspace_init)
+		mptcp_rcv_space_init(msk, ssk);
+
 	if (sk->sk_state == TCP_SYN_SENT) {
-		inet_sk_state_store(sk, TCP_ESTABLISHED);
+		/* subflow->idsn is always available is TCP_SYN_SENT state,
+		 * even for the FASTOPEN scenarios
+		 */
+		WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
+		WRITE_ONCE(msk->snd_nxt, msk->write_seq);
+		mptcp_set_state(sk, state);
 		sk->sk_state_change(sk);
 	}
 }
 
-static void mptcp_set_connected(struct sock *sk)
-{
-	mptcp_data_lock(sk);
-	if (!sock_owned_by_user(sk))
-		__mptcp_set_connected(sk);
-	else
-		__set_bit(MPTCP_CONNECTED, &mptcp_sk(sk)->cb_flags);
-	mptcp_data_unlock(sk);
-}
-
 static void subflow_set_remote_key(struct mptcp_sock *msk,
 				   struct mptcp_subflow_context *subflow,
 				   const struct mptcp_options_received *mp_opt)
@@ -459,6 +462,31 @@ static void subflow_set_remote_key(struct mptcp_sock *msk,
 	atomic64_set(&msk->rcv_wnd_sent, subflow->iasn);
 }
 
+static void mptcp_propagate_state(struct sock *sk, struct sock *ssk,
+				  struct mptcp_subflow_context *subflow,
+				  const struct mptcp_options_received *mp_opt)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+
+	mptcp_data_lock(sk);
+	if (mp_opt) {
+		/* Options are available only in the non fallback cases
+		 * avoid updating rx path fields otherwise
+		 */
+		WRITE_ONCE(msk->snd_una, subflow->idsn + 1);
+		WRITE_ONCE(msk->wnd_end, subflow->idsn + 1 + tcp_sk(ssk)->snd_wnd);
+		subflow_set_remote_key(msk, subflow, mp_opt);
+	}
+
+	if (!sock_owned_by_user(sk)) {
+		__mptcp_sync_state(sk, ssk->sk_state);
+	} else {
+		msk->pending_state = ssk->sk_state;
+		__set_bit(MPTCP_SYNC_STATE, &msk->cb_flags);
+	}
+	mptcp_data_unlock(sk);
+}
+
 static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
@@ -480,7 +508,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 
 	mptcp_get_options(skb, &mp_opt);
 	if (subflow->request_mptcp) {
-		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) {
+		if (!(mp_opt.suboptions & OPTION_MPTCP_MPC_SYNACK)) {
 			MPTCP_INC_STATS(sock_net(sk),
 					MPTCP_MIB_MPCAPABLEACTIVEFALLBACK);
 			mptcp_do_fallback(sk);
@@ -493,14 +521,13 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 		if (mp_opt.deny_join_id0)
 			WRITE_ONCE(msk->pm.remote_deny_join_id0, true);
 		subflow->mp_capable = 1;
-		subflow_set_remote_key(msk, subflow, &mp_opt);
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEACK);
 		mptcp_finish_connect(sk);
-		mptcp_set_connected(parent);
+		mptcp_propagate_state(parent, sk, subflow, &mp_opt);
 	} else if (subflow->request_join) {
 		u8 hmac[SHA256_DIGEST_SIZE];
 
-		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ)) {
+		if (!(mp_opt.suboptions & OPTION_MPTCP_MPJ_SYNACK)) {
 			subflow->reset_reason = MPTCP_RST_EMPTCP;
 			goto do_reset;
 		}
@@ -539,8 +566,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 		}
 	} else if (mptcp_check_fallback(sk)) {
 fallback:
-		mptcp_rcv_space_init(msk, sk);
-		mptcp_set_connected(parent);
+		mptcp_propagate_state(parent, sk, subflow, NULL);
 	}
 	return;
 
@@ -725,17 +751,16 @@ void mptcp_subflow_drop_ctx(struct sock *ssk)
 	kfree_rcu(ctx, rcu);
 }
 
-void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
-				     const struct mptcp_options_received *mp_opt)
+void __mptcp_subflow_fully_established(struct mptcp_sock *msk,
+				       struct mptcp_subflow_context *subflow,
+				       const struct mptcp_options_received *mp_opt)
 {
-	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
-
 	subflow_set_remote_key(msk, subflow, mp_opt);
 	subflow->fully_established = 1;
 	WRITE_ONCE(msk->fully_established, true);
 
 	if (subflow->is_mptfo)
-		mptcp_fastopen_gen_msk_ackseq(msk, subflow, mp_opt);
+		__mptcp_fastopen_gen_msk_ackseq(msk, subflow, mp_opt);
 }
 
 static struct sock *subflow_syn_recv_sock(const struct sock *sk,
@@ -777,12 +802,13 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 		 * options.
 		 */
 		mptcp_get_options(skb, &mp_opt);
-		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC))
+		if (!(mp_opt.suboptions &
+		      (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_ACK)))
 			fallback = true;
 
 	} else if (subflow_req->mp_join) {
 		mptcp_get_options(skb, &mp_opt);
-		if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ) ||
+		if (!(mp_opt.suboptions & OPTION_MPTCP_MPJ_ACK) ||
 		    !subflow_hmac_valid(req, &mp_opt) ||
 		    !mptcp_can_accept_new_subflow(subflow_req->msk)) {
 			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC);
@@ -827,7 +853,6 @@ create_child:
 			 * mpc option
 			 */
 			if (mp_opt.suboptions & OPTION_MPTCP_MPC_ACK) {
-				mptcp_subflow_fully_established(ctx, &mp_opt);
 				mptcp_pm_fully_established(owner, child);
 				ctx->pm_notified = 1;
 			}
@@ -1737,10 +1762,9 @@ static void subflow_state_change(struct sock *sk)
 	msk = mptcp_sk(parent);
 	if (subflow_simultaneous_connect(sk)) {
 		mptcp_do_fallback(sk);
-		mptcp_rcv_space_init(msk, sk);
 		pr_fallback(msk);
 		subflow->conn_finished = 1;
-		mptcp_set_connected(parent);
+		mptcp_propagate_state(parent, sk, subflow, NULL);
 	}
 
 	/* as recvmsg() does not acquire the subflow socket for ssk selection
@@ -1976,6 +2000,17 @@ static void tcp_release_cb_override(struct sock *ssk)
 	tcp_release_cb(ssk);
 }
 
+static int tcp_abort_override(struct sock *ssk, int err)
+{
+	/* closing a listener subflow requires a great deal of care.
+	 * keep it simple and just prevent such operation
+	 */
+	if (inet_sk_state_load(ssk) == TCP_LISTEN)
+		return -EINVAL;
+
+	return tcp_abort(ssk, err);
+}
+
 static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = {
 	.name		= "mptcp",
 	.owner		= THIS_MODULE,
@@ -2020,6 +2055,7 @@ void __init mptcp_subflow_init(void)
 
 	tcp_prot_override = tcp_prot;
 	tcp_prot_override.release_cb = tcp_release_cb_override;
+	tcp_prot_override.diag_destroy = tcp_abort_override;
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 	/* In struct mptcp_subflow_request_sock, we assume the TCP request sock
@@ -2055,6 +2091,7 @@ void __init mptcp_subflow_init(void)
 
 	tcpv6_prot_override = tcpv6_prot;
 	tcpv6_prot_override.release_cb = tcp_release_cb_override;
+	tcpv6_prot_override.diag_destroy = tcp_abort_override;
 #endif
 
 	mptcp_diag_subflow_init(&subflow_ulp_ops);