mptcp: fix subflow's remote_id issues

This patch set the init remote_id to zero, otherwise it will be a random
number.

Then it added the missing subflow's remote_id setting code both in
__mptcp_subflow_connect and in subflow_ulp_clone.

Fixes: 01cacb00 ("mptcp: add netlink-based PM")
Fixes: ec3edaa7 ("mptcp: Add handling of outgoing MP_JOIN requests")
Fixes: f296234c ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/pm_netlink.c

@@ -181,9 +181,9 @@ static void check_work_pending(struct mptcp_sock *msk)
 
 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 {
+	struct mptcp_addr_info remote = { 0 };
 	struct sock *sk = (struct sock *)msk;
 	struct mptcp_pm_addr_entry *local;
-	struct mptcp_addr_info remote;
 	struct pm_nl_pernet *pernet;
 
 	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);

net/mptcp/subflow.c

@@ -1063,6 +1063,7 @@ int __mptcp_subflow_connect(struct sock *sk, int ifindex,
 	struct mptcp_sock *msk = mptcp_sk(sk);
 	struct mptcp_subflow_context *subflow;
 	struct sockaddr_storage addr;
+	int remote_id = remote->id;
 	int local_id = loc->id;
 	struct socket *sf;
 	struct sock *ssk;
@@ -1107,10 +1108,11 @@ int __mptcp_subflow_connect(struct sock *sk, int ifindex,
 		goto failed;
 
 	mptcp_crypto_key_sha(subflow->remote_key, &remote_token, NULL);
-	pr_debug("msk=%p remote_token=%u local_id=%d", msk, remote_token,
-		 local_id);
+	pr_debug("msk=%p remote_token=%u local_id=%d remote_id=%d", msk,
+		 remote_token, local_id, remote_id);
 	subflow->remote_token = remote_token;
 	subflow->local_id = local_id;
+	subflow->remote_id = remote_id;
 	subflow->request_join = 1;
 	subflow->request_bkup = 1;
 	mptcp_info2sockaddr(remote, &addr);
@@ -1347,6 +1349,7 @@ static void subflow_ulp_clone(const struct request_sock *req,
 		new_ctx->fully_established = 1;
 		new_ctx->backup = subflow_req->backup;
 		new_ctx->local_id = subflow_req->local_id;
+		new_ctx->remote_id = subflow_req->remote_id;
 		new_ctx->token = subflow_req->token;
 		new_ctx->thmac = subflow_req->thmac;
 	}