From ccae357c1c6a76c3b46f12ae18d7679d871c9390 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 11 Aug 2023 17:57:15 +0200 Subject: mptcp: avoid additional __inet_stream_connect() call The mptcp protocol maintains an additional socket just to easily invoke a few stream operations on the first subflow. One of them is __inet_stream_connect(). We are going to remove the first subflow socket soon, so avoid the additional indirection via at connect time, calling directly into the sock-level connect() ops. The sk-level connect never return -EINPROGRESS, cleanup the error path accordingly. Additionally, the ssk status on error is always TCP_CLOSE. Avoid unneeded access to the subflow sk state. No functional change intended. Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 49 +++++++++++++++++++++++++++++++++---------------- 1 file changed, 33 insertions(+), 16 deletions(-) (limited to 'net/mptcp') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index abb310548c37..b888d6339c80 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3589,22 +3589,24 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) struct mptcp_sock *msk = mptcp_sk(sk); struct socket *ssock; int err = -EINVAL; + struct sock *ssk; ssock = __mptcp_nmpc_socket(msk); if (IS_ERR(ssock)) return PTR_ERR(ssock); inet_sk_state_store(sk, TCP_SYN_SENT); - subflow = mptcp_subflow_ctx(ssock->sk); + ssk = msk->first; + subflow = mptcp_subflow_ctx(ssk); #ifdef CONFIG_TCP_MD5SIG /* no MPTCP if MD5SIG is enabled on this socket or we may run out of * TCP option space. */ - if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) + if (rcu_access_pointer(tcp_sk(ssk)->md5sig_info)) mptcp_subflow_early_fallback(msk, subflow); #endif - if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) { - MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT); + if (subflow->request_mptcp && mptcp_token_new_connect(ssk)) { + MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_TOKENFALLBACKINIT); mptcp_subflow_early_fallback(msk, subflow); } if (likely(!__mptcp_check_fallback(msk))) @@ -3613,27 +3615,42 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) /* if reaching here via the fastopen/sendmsg path, the caller already * acquired the subflow socket lock, too. */ - if (msk->fastopening) - err = __inet_stream_connect(ssock, uaddr, addr_len, O_NONBLOCK, 1); - else - err = inet_stream_connect(ssock, uaddr, addr_len, O_NONBLOCK); - inet_sk(sk)->defer_connect = inet_sk(ssock->sk)->defer_connect; + if (!msk->fastopening) + lock_sock(ssk); + + /* the following mirrors closely a very small chunk of code from + * __inet_stream_connect() + */ + if (ssk->sk_state != TCP_CLOSE) + goto out; + + if (BPF_CGROUP_PRE_CONNECT_ENABLED(ssk)) { + err = ssk->sk_prot->pre_connect(ssk, uaddr, addr_len); + if (err) + goto out; + } + + err = ssk->sk_prot->connect(ssk, uaddr, addr_len); + if (err < 0) + goto out; + + inet_sk(sk)->defer_connect = inet_sk(ssk)->defer_connect; + +out: + if (!msk->fastopening) + release_sock(ssk); /* on successful connect, the msk state will be moved to established by * subflow_finish_connect() */ - if (unlikely(err && err != -EINPROGRESS)) { + if (unlikely(err)) { /* avoid leaving a dangling token in an unconnected socket */ mptcp_token_destroy(msk); - inet_sk_state_store(sk, inet_sk_state_load(ssock->sk)); + inet_sk_state_store(sk, TCP_CLOSE); return err; } - mptcp_copy_inaddrs(sk, ssock->sk); - - /* silence EINPROGRESS and let the caller inet_stream_connect - * handle the connection in progress - */ + mptcp_copy_inaddrs(sk, ssk); return 0; } -- cgit v1.2.3