1 files changed, 35 insertions, 8 deletions

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index d17d39ccdf34..3c19a5265a0f 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -115,6 +115,16 @@ static bool subflow_use_different_sport(struct mptcp_sock *msk, const struct soc
 	return inet_sk(sk)->inet_sport != inet_sk((struct sock *)msk)->inet_sport;
 }
 
+static void subflow_add_reset_reason(struct sk_buff *skb, u8 reason)
+{
+	struct mptcp_ext *mpext = skb_ext_add(skb, SKB_EXT_MPTCP);
+
+	if (mpext) {
+		memset(mpext, 0, sizeof(*mpext));
+		mpext->reset_reason = reason;
+	}
+}
+
 /* Init mptcp request socket.
  *
  * Returns an error code if a JOIN has failed and a TCP reset
@@ -165,6 +175,7 @@ again:
 			if (mptcp_token_exists(subflow_req->token)) {
 				if (retries-- > 0)
 					goto again;
+				SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT);
 			} else {
 				subflow_req->mp_capable = 1;
 			}
@@ -176,6 +187,8 @@ again:
 			subflow_req->mp_capable = 1;
 		else if (retries-- > 0)
 			goto again;
+		else
+			SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT);
 
 	} else if (mp_opt.mp_join && listener->request_mptcp) {
 		subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
@@ -187,8 +200,10 @@ again:
 		subflow_req->msk = subflow_token_join_request(req);
 
 		/* Can't fall back to TCP in this case. */
-		if (!subflow_req->msk)
+		if (!subflow_req->msk) {
+			subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP);
 			return -EPERM;
+		}
 
 		if (subflow_use_different_sport(subflow_req->msk, sk_listener)) {
 			pr_debug("syn inet_sport=%d %d",
@@ -392,12 +407,15 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 		subflow->remote_key = mp_opt.sndr_key;
 		pr_debug("subflow=%p, remote_key=%llu", subflow,
 			 subflow->remote_key);
+		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEACK);
 		mptcp_finish_connect(sk);
 	} else if (subflow->request_join) {
 		u8 hmac[SHA256_DIGEST_SIZE];
 
-		if (!mp_opt.mp_join)
+		if (!mp_opt.mp_join) {
+			subflow->reset_reason = MPTCP_RST_EMPTCP;
 			goto do_reset;
+		}
 
 		subflow->thmac = mp_opt.thmac;
 		subflow->remote_nonce = mp_opt.nonce;
@@ -406,6 +424,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 
 		if (!subflow_thmac_valid(subflow)) {
 			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC);
+			subflow->reset_reason = MPTCP_RST_EMPTCP;
 			goto do_reset;
 		}
 
@@ -434,6 +453,7 @@ fallback:
 	return;
 
 do_reset:
+	subflow->reset_transient = 0;
 	mptcp_subflow_reset(sk);
 }
 
@@ -650,8 +670,10 @@ create_child:
 		 * to reset the context to non MPTCP status.
 		 */
 		if (!ctx || fallback) {
-			if (fallback_is_fatal)
+			if (fallback_is_fatal) {
+				subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP);
 				goto dispose_child;
+			}
 
 			subflow_drop_ctx(child);
 			goto out;
@@ -686,8 +708,10 @@ create_child:
 			struct mptcp_sock *owner;
 
 			owner = subflow_req->msk;
-			if (!owner)
+			if (!owner) {
+				subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT);
 				goto dispose_child;
+			}
 
 			/* move the msk reference ownership to the subflow */
 			subflow_req->msk = NULL;
@@ -1052,6 +1076,8 @@ fatal:
 	smp_wmb();
 	ssk->sk_error_report(ssk);
 	tcp_set_state(ssk, TCP_CLOSE);
+	subflow->reset_transient = 0;
+	subflow->reset_reason = MPTCP_RST_EMPTCP;
 	tcp_send_active_reset(ssk, GFP_ATOMIC);
 	subflow->data_avail = 0;
 	return false;
@@ -1081,7 +1107,7 @@ bool mptcp_subflow_data_available(struct sock *sk)
  * In mptcp, rwin is about the mptcp-level connection data.
  *
  * Data that is still on the ssk rx queue can thus be ignored,
- * as far as mptcp peer is concerened that data is still inflight.
+ * as far as mptcp peer is concerned that data is still inflight.
  * DSS ACK is updated when skb is moved to the mptcp rx queue.
  */
 void mptcp_space(const struct sock *ssk, int *space, int *full_space)
@@ -1230,7 +1256,8 @@ void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
 }
 
 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
-			    const struct mptcp_addr_info *remote)
+			    const struct mptcp_addr_info *remote,
+			    u8 flags, int ifindex)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
 	struct mptcp_subflow_context *subflow;
@@ -1274,7 +1301,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 	if (addr.ss_family == AF_INET6)
 		addrlen = sizeof(struct sockaddr_in6);
 #endif
-	ssk->sk_bound_dev_if = loc->ifindex;
+	ssk->sk_bound_dev_if = ifindex;
 	err = kernel_bind(sf, (struct sockaddr *)&addr, addrlen);
 	if (err)
 		goto failed;
@@ -1286,7 +1313,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 	subflow->local_id = local_id;
 	subflow->remote_id = remote_id;
 	subflow->request_join = 1;
-	subflow->request_bkup = !!(loc->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+	subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 	mptcp_info2sockaddr(remote, &addr, ssk->sk_family);
 
 	mptcp_add_pending_subflow(msk, subflow);