1 files changed, 357 insertions, 46 deletions

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 65122edf60aa..b5180c81588e 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
+#include <crypto/algapi.h>
 #include <net/sock.h>
 #include <net/inet_common.h>
 #include <net/inet_hashtables.h>
@@ -19,17 +20,42 @@
 #endif
 #include <net/mptcp.h>
 #include "protocol.h"
+#include "mib.h"
+
+static void SUBFLOW_REQ_INC_STATS(struct request_sock *req,
+				  enum linux_mptcp_mib_field field)
+{
+	MPTCP_INC_STATS(sock_net(req_to_sk(req)), field);
+}
 
 static int subflow_rebuild_header(struct sock *sk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-	int err = 0;
+	int local_id, err = 0;
 
 	if (subflow->request_mptcp && !subflow->token) {
 		pr_debug("subflow=%p", sk);
 		err = mptcp_token_new_connect(sk);
+	} else if (subflow->request_join && !subflow->local_nonce) {
+		struct mptcp_sock *msk = (struct mptcp_sock *)subflow->conn;
+
+		pr_debug("subflow=%p", sk);
+
+		do {
+			get_random_bytes(&subflow->local_nonce, sizeof(u32));
+		} while (!subflow->local_nonce);
+
+		if (subflow->local_id)
+			goto out;
+
+		local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)sk);
+		if (local_id < 0)
+			return -EINVAL;
+
+		subflow->local_id = local_id;
 	}
 
+out:
 	if (err)
 		return err;
 
@@ -47,6 +73,51 @@ static void subflow_req_destructor(struct request_sock *req)
 	tcp_request_sock_ops.destructor(req);
 }
 
+static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
+				  void *hmac)
+{
+	u8 msg[8];
+
+	put_unaligned_be32(nonce1, &msg[0]);
+	put_unaligned_be32(nonce2, &msg[4]);
+
+	mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac);
+}
+
+/* validate received token and create truncated hmac and nonce for SYN-ACK */
+static bool subflow_token_join_request(struct request_sock *req,
+				       const struct sk_buff *skb)
+{
+	struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
+	u8 hmac[MPTCPOPT_HMAC_LEN];
+	struct mptcp_sock *msk;
+	int local_id;
+
+	msk = mptcp_token_get_sock(subflow_req->token);
+	if (!msk) {
+		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINNOTOKEN);
+		return false;
+	}
+
+	local_id = mptcp_pm_get_local_id(msk, (struct sock_common *)req);
+	if (local_id < 0) {
+		sock_put((struct sock *)msk);
+		return false;
+	}
+	subflow_req->local_id = local_id;
+
+	get_random_bytes(&subflow_req->local_nonce, sizeof(u32));
+
+	subflow_generate_hmac(msk->local_key, msk->remote_key,
+			      subflow_req->local_nonce,
+			      subflow_req->remote_nonce, hmac);
+
+	subflow_req->thmac = get_unaligned_be64(hmac);
+
+	sock_put((struct sock *)msk);
+	return true;
+}
+
 static void subflow_init_req(struct request_sock *req,
 			     const struct sock *sk_listener,
 			     struct sk_buff *skb)
@@ -61,6 +132,7 @@ static void subflow_init_req(struct request_sock *req,
 	mptcp_get_options(skb, &rx_opt);
 
 	subflow_req->mp_capable = 0;
+	subflow_req->mp_join = 0;
 	subflow_req->remote_key_valid = 0;
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -71,6 +143,15 @@ static void subflow_init_req(struct request_sock *req,
 		return;
 #endif
 
+	if (rx_opt.mptcp.mp_capable) {
+		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE);
+
+		if (rx_opt.mptcp.mp_join)
+			return;
+	} else if (rx_opt.mptcp.mp_join) {
+		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX);
+	}
+
 	if (rx_opt.mptcp.mp_capable && listener->request_mptcp) {
 		int err;
 
@@ -79,6 +160,19 @@ static void subflow_init_req(struct request_sock *req,
 			subflow_req->mp_capable = 1;
 
 		subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
+	} else if (rx_opt.mptcp.mp_join && listener->request_mptcp) {
+		subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
+		subflow_req->mp_join = 1;
+		subflow_req->backup = rx_opt.mptcp.backup;
+		subflow_req->remote_id = rx_opt.mptcp.join_id;
+		subflow_req->token = rx_opt.mptcp.token;
+		subflow_req->remote_nonce = rx_opt.mptcp.nonce;
+		pr_debug("token=%u, remote_nonce=%u", subflow_req->token,
+			 subflow_req->remote_nonce);
+		if (!subflow_token_join_request(req, skb)) {
+			subflow_req->mp_join = 0;
+			// @@ need to trigger RST
+		}
 	}
 }
 
@@ -106,13 +200,41 @@ static void subflow_v6_init_req(struct request_sock *req,
 }
 #endif
 
+/* validate received truncated hmac and create hmac for third ACK */
+static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow)
+{
+	u8 hmac[MPTCPOPT_HMAC_LEN];
+	u64 thmac;
+
+	subflow_generate_hmac(subflow->remote_key, subflow->local_key,
+			      subflow->remote_nonce, subflow->local_nonce,
+			      hmac);
+
+	thmac = get_unaligned_be64(hmac);
+	pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n",
+		 subflow, subflow->token,
+		 (unsigned long long)thmac,
+		 (unsigned long long)subflow->thmac);
+
+	return thmac == subflow->thmac;
+}
+
 static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+	struct sock *parent = subflow->conn;
 
 	subflow->icsk_af_ops->sk_rx_dst_set(sk, skb);
 
-	if (subflow->conn && !subflow->conn_finished) {
+	if (inet_sk_state_load(parent) != TCP_ESTABLISHED) {
+		inet_sk_state_store(parent, TCP_ESTABLISHED);
+		parent->sk_state_change(parent);
+	}
+
+	if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp)
+		return;
+
+	if (subflow->mp_capable) {
 		pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk),
 			 subflow->remote_key);
 		mptcp_finish_connect(sk);
@@ -122,6 +244,33 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 			pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq);
 			subflow->ssn_offset = TCP_SKB_CB(skb)->seq;
 		}
+	} else if (subflow->mp_join) {
+		pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u",
+			 subflow, subflow->thmac,
+			 subflow->remote_nonce);
+		if (!subflow_thmac_valid(subflow)) {
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC);
+			subflow->mp_join = 0;
+			goto do_reset;
+		}
+
+		subflow_generate_hmac(subflow->local_key, subflow->remote_key,
+				      subflow->local_nonce,
+				      subflow->remote_nonce,
+				      subflow->hmac);
+
+		if (skb)
+			subflow->ssn_offset = TCP_SKB_CB(skb)->seq;
+
+		if (!mptcp_finish_join(sk))
+			goto do_reset;
+
+		subflow->conn_finished = 1;
+		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);
+	} else {
+do_reset:
+		tcp_send_active_reset(sk, GFP_ATOMIC);
+		tcp_done(sk);
 	}
 }
 
@@ -172,6 +321,32 @@ drop:
 }
 #endif
 
+/* validate hmac received in third ACK */
+static bool subflow_hmac_valid(const struct request_sock *req,
+			       const struct tcp_options_received *rx_opt)
+{
+	const struct mptcp_subflow_request_sock *subflow_req;
+	u8 hmac[MPTCPOPT_HMAC_LEN];
+	struct mptcp_sock *msk;
+	bool ret;
+
+	subflow_req = mptcp_subflow_rsk(req);
+	msk = mptcp_token_get_sock(subflow_req->token);
+	if (!msk)
+		return false;
+
+	subflow_generate_hmac(msk->remote_key, msk->local_key,
+			      subflow_req->remote_nonce,
+			      subflow_req->local_nonce, hmac);
+
+	ret = true;
+	if (crypto_memneq(hmac, rx_opt->mptcp.hmac, sizeof(hmac)))
+		ret = false;
+
+	sock_put((struct sock *)msk);
+	return ret;
+}
+
 static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 					  struct sk_buff *skb,
 					  struct request_sock *req,
@@ -182,6 +357,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 	struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk);
 	struct mptcp_subflow_request_sock *subflow_req;
 	struct tcp_options_received opt_rx;
+	bool fallback_is_fatal = false;
+	struct sock *new_msk = NULL;
 	struct sock *child;
 
 	pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn);
@@ -197,7 +374,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 			 * out-of-order pkt, which will not carry the MP_CAPABLE
 			 * opt even on mptcp enabled paths
 			 */
-			goto create_child;
+			goto create_msk;
 		}
 
 		opt_rx.mptcp.mp_capable = 0;
@@ -207,6 +384,21 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 			subflow_req->remote_key_valid = 1;
 		} else {
 			subflow_req->mp_capable = 0;
+			goto create_child;
+		}
+
+create_msk:
+		new_msk = mptcp_sk_clone(listener->conn, req);
+		if (!new_msk)
+			subflow_req->mp_capable = 0;
+	} else if (subflow_req->mp_join) {
+		fallback_is_fatal = true;
+		opt_rx.mptcp.mp_join = 0;
+		mptcp_get_options(skb, &opt_rx);
+		if (!opt_rx.mptcp.mp_join ||
+		    !subflow_hmac_valid(req, &opt_rx)) {
+			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC);
+			return NULL;
 		}
 	}
 
@@ -217,22 +409,45 @@ create_child:
 	if (child && *own_req) {
 		struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child);
 
-		/* we have null ctx on TCP fallback, not fatal on MPC
-		 * handshake
+		/* we have null ctx on TCP fallback, which is fatal on
+		 * MPJ handshake
 		 */
-		if (!ctx)
-			return child;
+		if (!ctx) {
+			if (fallback_is_fatal)
+				goto close_child;
+			goto out;
+		}
 
 		if (ctx->mp_capable) {
-			if (mptcp_token_new_accept(ctx->token))
+			/* new mpc subflow takes ownership of the newly
+			 * created mptcp socket
+			 */
+			inet_sk_state_store(new_msk, TCP_ESTABLISHED);
+			mptcp_pm_new_connection(mptcp_sk(new_msk), 1);
+			ctx->conn = new_msk;
+			new_msk = NULL;
+		} else if (ctx->mp_join) {
+			struct mptcp_sock *owner;
+
+			owner = mptcp_token_get_sock(ctx->token);
+			if (!owner)
 				goto close_child;
+
+			ctx->conn = (struct sock *)owner;
+			if (!mptcp_finish_join(child))
+				goto close_child;
+
+			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX);
 		}
 	}
 
+out:
+	/* dispose of the left over mptcp master, if any */
+	if (unlikely(new_msk))
+		sock_put(new_msk);
 	return child;
 
 close_child:
-	pr_debug("closing child socket");
 	tcp_send_active_reset(child, GFP_ATOMIC);
 	inet_csk_prepare_forced_close(child);
 	tcp_done(child);
@@ -338,6 +553,7 @@ static enum mapping_status get_mapping_status(struct sock *ssk)
 	data_len = mpext->data_len;
 	if (data_len == 0) {
 		pr_err("Infinite mapping not handled");
+		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX);
 		return MAPPING_INVALID;
 	}
 
@@ -381,8 +597,10 @@ static enum mapping_status get_mapping_status(struct sock *ssk)
 		/* If this skb data are fully covered by the current mapping,
 		 * the new map would need caching, which is not supported
 		 */
-		if (skb_is_fully_mapped(ssk, skb))
+		if (skb_is_fully_mapped(ssk, skb)) {
+			MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSNOMATCH);
 			return MAPPING_INVALID;
+		}
 
 		/* will validate the next map after consuming the current one */
 		return MAPPING_OK;
@@ -408,6 +626,18 @@ validate_seq:
 	return MAPPING_OK;
 }
 
+static int subflow_read_actor(read_descriptor_t *desc,
+			      struct sk_buff *skb,
+			      unsigned int offset, size_t len)
+{
+	size_t copy_len = min(desc->count, len);
+
+	desc->count -= copy_len;
+
+	pr_debug("flushed %zu bytes, %zu left", copy_len, desc->count);
+	return copy_len;
+}
+
 static bool subflow_check_data_avail(struct sock *ssk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
@@ -420,9 +650,6 @@ static bool subflow_check_data_avail(struct sock *ssk)
 	if (subflow->data_avail)
 		return true;
 
-	if (!subflow->conn)
-		return false;
-
 	msk = mptcp_sk(subflow->conn);
 	for (;;) {
 		u32 map_remaining;
@@ -482,16 +709,12 @@ static bool subflow_check_data_avail(struct sock *ssk)
 		pr_debug("discarding %zu bytes, current map len=%d", delta,
 			 map_remaining);
 		if (delta) {
-			struct mptcp_read_arg arg = {
-				.msg = NULL,
-			};
 			read_descriptor_t desc = {
 				.count = delta,
-				.arg.data = &arg,
 			};
 			int ret;
 
-			ret = tcp_read_sock(ssk, &desc, mptcp_read_actor);
+			ret = tcp_read_sock(ssk, &desc, subflow_read_actor);
 			if (ret < 0) {
 				ssk->sk_err = -ret;
 				goto fatal;
@@ -546,19 +769,15 @@ static void subflow_data_ready(struct sock *sk)
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct sock *parent = subflow->conn;
 
-	if (!parent || !subflow->mp_capable) {
+	if (!subflow->mp_capable && !subflow->mp_join) {
 		subflow->tcp_data_ready(sk);
 
-		if (parent)
-			parent->sk_data_ready(parent);
+		parent->sk_data_ready(parent);
 		return;
 	}
 
-	if (mptcp_subflow_data_available(sk)) {
-		set_bit(MPTCP_DATA_READY, &mptcp_sk(parent)->flags);
-
-		parent->sk_data_ready(parent);
-	}
+	if (mptcp_subflow_data_available(sk))
+		mptcp_data_ready(parent, sk);
 }
 
 static void subflow_write_space(struct sock *sk)
@@ -567,7 +786,7 @@ static void subflow_write_space(struct sock *sk)
 	struct sock *parent = subflow->conn;
 
 	sk_stream_write_space(sk);
-	if (parent && sk_stream_is_writeable(sk)) {
+	if (sk_stream_is_writeable(sk)) {
 		set_bit(MPTCP_SEND_SPACE, &mptcp_sk(parent)->flags);
 		smp_mb__after_atomic();
 		/* set SEND_SPACE before sk_stream_write_space clears NOSPACE */
@@ -605,6 +824,85 @@ void mptcpv6_handle_mapped(struct sock *sk, bool mapped)
 }
 #endif
 
+static void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
+				struct sockaddr_storage *addr)
+{
+	memset(addr, 0, sizeof(*addr));
+	addr->ss_family = info->family;
+	if (addr->ss_family == AF_INET) {
+		struct sockaddr_in *in_addr = (struct sockaddr_in *)addr;
+
+		in_addr->sin_addr = info->addr;
+		in_addr->sin_port = info->port;
+	}
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	else if (addr->ss_family == AF_INET6) {
+		struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)addr;
+
+		in6_addr->sin6_addr = info->addr6;
+		in6_addr->sin6_port = info->port;
+	}
+#endif
+}
+
+int __mptcp_subflow_connect(struct sock *sk, int ifindex,
+			    const struct mptcp_addr_info *loc,
+			    const struct mptcp_addr_info *remote)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	struct mptcp_subflow_context *subflow;
+	struct sockaddr_storage addr;
+	struct socket *sf;
+	u32 remote_token;
+	int addrlen;
+	int err;
+
+	if (sk->sk_state != TCP_ESTABLISHED)
+		return -ENOTCONN;
+
+	err = mptcp_subflow_create_socket(sk, &sf);
+	if (err)
+		return err;
+
+	subflow = mptcp_subflow_ctx(sf->sk);
+	subflow->remote_key = msk->remote_key;
+	subflow->local_key = msk->local_key;
+	subflow->token = msk->token;
+	mptcp_info2sockaddr(loc, &addr);
+
+	addrlen = sizeof(struct sockaddr_in);
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	if (loc->family == AF_INET6)
+		addrlen = sizeof(struct sockaddr_in6);
+#endif
+	sf->sk->sk_bound_dev_if = ifindex;
+	err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen);
+	if (err)
+		goto failed;
+
+	mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL);
+	pr_debug("msk=%p remote_token=%u", msk, remote_token);
+	subflow->remote_token = remote_token;
+	subflow->local_id = loc->id;
+	subflow->request_join = 1;
+	subflow->request_bkup = 1;
+	mptcp_info2sockaddr(remote, &addr);
+
+	err = kernel_connect(sf, (struct sockaddr *)&addr, addrlen, O_NONBLOCK);
+	if (err && err != -EINPROGRESS)
+		goto failed;
+
+	spin_lock_bh(&msk->join_list_lock);
+	list_add_tail(&subflow->node, &msk->join_list);
+	spin_unlock_bh(&msk->join_list_lock);
+
+	return err;
+
+failed:
+	sock_release(sf);
+	return err;
+}
+
 int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock)
 {
 	struct mptcp_subflow_context *subflow;
@@ -682,7 +980,7 @@ static bool subflow_is_done(const struct sock *sk)
 static void subflow_state_change(struct sock *sk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-	struct sock *parent = READ_ONCE(subflow->conn);
+	struct sock *parent = subflow->conn;
 
 	__subflow_state_change(sk);
 
@@ -690,13 +988,10 @@ static void subflow_state_change(struct sock *sk)
 	 * a fin packet carrying a DSS can be unnoticed if we don't trigger
 	 * the data available machinery here.
 	 */
-	if (parent && subflow->mp_capable && mptcp_subflow_data_available(sk)) {
-		set_bit(MPTCP_DATA_READY, &mptcp_sk(parent)->flags);
-
-		parent->sk_data_ready(parent);
-	}
+	if (subflow->mp_capable && mptcp_subflow_data_available(sk))
+		mptcp_data_ready(parent, sk);
 
-	if (parent && !(parent->sk_shutdown & RCV_SHUTDOWN) &&
+	if (!(parent->sk_shutdown & RCV_SHUTDOWN) &&
 	    !subflow->rx_eof && subflow_is_done(sk)) {
 		subflow->rx_eof = 1;
 		parent->sk_shutdown |= RCV_SHUTDOWN;
@@ -772,7 +1067,8 @@ static void subflow_ulp_clone(const struct request_sock *req,
 	struct mptcp_subflow_context *old_ctx = mptcp_subflow_ctx(newsk);
 	struct mptcp_subflow_context *new_ctx;
 
-	if (!tcp_rsk(req)->is_mptcp || !subflow_req->mp_capable) {
+	if (!tcp_rsk(req)->is_mptcp ||
+	    (!subflow_req->mp_capable && !subflow_req->mp_join)) {
 		subflow_ulp_fallback(newsk, old_ctx);
 		return;
 	}
@@ -783,22 +1079,35 @@ static void subflow_ulp_clone(const struct request_sock *req,
 		return;
 	}
 
-	/* see comments in subflow_syn_recv_sock(), MPTCP connection is fully
-	 * established only after we receive the remote key
-	 */
 	new_ctx->conn_finished = 1;
 	new_ctx->icsk_af_ops = old_ctx->icsk_af_ops;
 	new_ctx->tcp_data_ready = old_ctx->tcp_data_ready;
 	new_ctx->tcp_state_change = old_ctx->tcp_state_change;
 	new_ctx->tcp_write_space = old_ctx->tcp_write_space;
-	new_ctx->mp_capable = 1;
-	new_ctx->fourth_ack = subflow_req->remote_key_valid;
-	new_ctx->can_ack = subflow_req->remote_key_valid;
-	new_ctx->remote_key = subflow_req->remote_key;
-	new_ctx->local_key = subflow_req->local_key;
-	new_ctx->token = subflow_req->token;
-	new_ctx->ssn_offset = subflow_req->ssn_offset;
-	new_ctx->idsn = subflow_req->idsn;
+	new_ctx->rel_write_seq = 1;
+	new_ctx->tcp_sock = newsk;
+
+	if (subflow_req->mp_capable) {
+		/* see comments in subflow_syn_recv_sock(), MPTCP connection
+		 * is fully established only after we receive the remote key
+		 */
+		new_ctx->mp_capable = 1;
+		new_ctx->fully_established = subflow_req->remote_key_valid;
+		new_ctx->can_ack = subflow_req->remote_key_valid;
+		new_ctx->remote_key = subflow_req->remote_key;
+		new_ctx->local_key = subflow_req->local_key;
+		new_ctx->token = subflow_req->token;
+		new_ctx->ssn_offset = subflow_req->ssn_offset;
+		new_ctx->idsn = subflow_req->idsn;
+	} else if (subflow_req->mp_join) {
+		new_ctx->ssn_offset = subflow_req->ssn_offset;
+		new_ctx->mp_join = 1;
+		new_ctx->fully_established = 1;
+		new_ctx->backup = subflow_req->backup;
+		new_ctx->local_id = subflow_req->local_id;
+		new_ctx->token = subflow_req->token;
+		new_ctx->thmac = subflow_req->thmac;
+	}
 }
 
 static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = {
@@ -860,6 +1169,8 @@ void mptcp_subflow_init(void)
 	subflow_v6m_specific.net_frag_header_len = 0;
 #endif
 
+	mptcp_diag_subflow_init(&subflow_ulp_ops);
+
 	if (tcp_register_ulp(&subflow_ulp_ops) != 0)
 		panic("MPTCP: failed to register subflows to ULP\n");
 }