mptcp: do nonce initialization at subflow creation time

This clean-up the code a bit, reduces the number of
used hooks and indirect call requested, and allow
better error reporting from __mptcp_subflow_connect()

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 548f9e3..664aa91 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -29,34 +29,6 @@ static void SUBFLOW_REQ_INC_STATS(struct request_sock *req,
        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 local_id;
-
-       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:
-       return subflow->icsk_af_ops->rebuild_header(sk);
-}
-
 static void subflow_req_destructor(struct request_sock *req)
 {
        struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
@@ -984,7 +956,9 @@ 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 local_id = loc->id;
        struct socket *sf;
+       struct sock *ssk;
        u32 remote_token;
        int addrlen;
        int err;
@@ -996,7 +970,20 @@ int __mptcp_subflow_connect(struct sock *sk, int ifindex,
        if (err)
                return err;
 
-       subflow = mptcp_subflow_ctx(sf->sk);
+       ssk = sf->sk;
+       subflow = mptcp_subflow_ctx(ssk);
+       do {
+               get_random_bytes(&subflow->local_nonce, sizeof(u32));
+       } while (!subflow->local_nonce);
+
+       if (!local_id) {
+               err = mptcp_pm_get_local_id(msk, (struct sock_common *)ssk);
+               if (err < 0)
+                       goto failed;
+
+               local_id = err;
+       }
+
        subflow->remote_key = msk->remote_key;
        subflow->local_key = msk->local_key;
        subflow->token = msk->token;
@@ -1007,15 +994,16 @@ int __mptcp_subflow_connect(struct sock *sk, int ifindex,
        if (loc->family == AF_INET6)
                addrlen = sizeof(struct sockaddr_in6);
 #endif
-       sf->sk->sk_bound_dev_if = ifindex;
+       ssk->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);
+       pr_debug("msk=%p remote_token=%u local_id=%d", msk, remote_token,
+                local_id);
        subflow->remote_token = remote_token;
-       subflow->local_id = loc->id;
+       subflow->local_id = local_id;
        subflow->request_join = 1;
        subflow->request_bkup = 1;
        mptcp_info2sockaddr(remote, &addr);
@@ -1288,7 +1276,6 @@ void __init mptcp_subflow_init(void)
        subflow_specific.conn_request = subflow_v4_conn_request;
        subflow_specific.syn_recv_sock = subflow_syn_recv_sock;
        subflow_specific.sk_rx_dst_set = subflow_finish_connect;
-       subflow_specific.rebuild_header = subflow_rebuild_header;
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
        subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops;
@@ -1298,7 +1285,6 @@ void __init mptcp_subflow_init(void)
        subflow_v6_specific.conn_request = subflow_v6_conn_request;
        subflow_v6_specific.syn_recv_sock = subflow_syn_recv_sock;
        subflow_v6_specific.sk_rx_dst_set = subflow_finish_connect;
-       subflow_v6_specific.rebuild_header = subflow_rebuild_header;
 
        subflow_v6m_specific = subflow_v6_specific;
        subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit;