From: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>
Cc: Benjamin Herrenschmidt <benh@amazon.com>,
Kuniyuki Iwashima <kuniyu@amazon.co.jp>,
Kuniyuki Iwashima <kuni1840@gmail.com>, <bpf@vger.kernel.org>,
<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v2 bpf-next 05/13] tcp: Set the new listener to migrated TFO requests.
Date: Mon, 7 Dec 2020 22:24:48 +0900 [thread overview]
Message-ID: <20201207132456.65472-6-kuniyu@amazon.co.jp> (raw)
In-Reply-To: <20201207132456.65472-1-kuniyu@amazon.co.jp>
A TFO request socket is only freed after BOTH 3WHS has completed (or
aborted) and the child socket has been accepted (or its listener has been
closed). Hence, depending on the order, there can be two kinds of request
sockets in the accept queue.
3WHS -> accept : TCP_ESTABLISHED
accept -> 3WHS : TCP_SYN_RECV
Unlike TCP_ESTABLISHED socket, accept() does not free the request socket
for TCP_SYN_RECV socket. It is freed later at reqsk_fastopen_remove().
Also, it accesses request_sock.rsk_listener. So, in order to complete TFO
socket migration, we have to set the current listener to it at accept()
before reqsk_fastopen_remove().
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
---
net/ipv4/inet_connection_sock.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 5da38a756e4c..143590858c2e 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -500,6 +500,16 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
tcp_rsk(req)->tfo_listener) {
spin_lock_bh(&queue->fastopenq.lock);
if (tcp_rsk(req)->tfo_listener) {
+ if (req->rsk_listener != sk) {
+ /* TFO request was migrated to another listener so
+ * the new listener must be used in reqsk_fastopen_remove()
+ * to hold requests which cause RST.
+ */
+ sock_put(req->rsk_listener);
+ sock_hold(sk);
+ req->rsk_listener = sk;
+ }
+
/* We are still waiting for the final ACK from 3WHS
* so can't free req now. Instead, we set req->sk to
* NULL to signify that the child socket is taken
@@ -954,7 +964,6 @@ static void inet_child_forget(struct sock *sk, struct request_sock *req,
if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {
BUG_ON(rcu_access_pointer(tcp_sk(child)->fastopen_rsk) != req);
- BUG_ON(sk != req->rsk_listener);
/* Paranoid, to prevent race condition if
* an inbound pkt destined for child is
--
2.17.2 (Apple Git-113)
next prev parent reply other threads:[~2020-12-07 13:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 13:24 [PATCH v2 bpf-next 00/13] Socket migration for SO_REUSEPORT Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 01/13] tcp: Allow TCP_CLOSE sockets to hold the reuseport group Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 02/13] bpf: Define migration types for SO_REUSEPORT Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 03/13] Revert "locking/spinlocks: Remove the unused spin_lock_bh_nested() API" Kuniyuki Iwashima
2020-12-07 16:25 ` Waiman Long
2020-12-07 13:24 ` [PATCH v2 bpf-next 04/13] tcp: Introduce inet_csk_reqsk_queue_migrate() Kuniyuki Iwashima
2020-12-07 13:24 ` Kuniyuki Iwashima [this message]
2020-12-07 13:24 ` [PATCH v2 bpf-next 06/13] tcp: Migrate TCP_ESTABLISHED/TCP_SYN_RECV sockets in accept queues Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 07/13] tcp: Migrate TCP_NEW_SYN_RECV requests Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 08/13] bpf: Introduce two attach types for BPF_PROG_TYPE_SK_REUSEPORT Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 09/13] libbpf: Set expected_attach_type " Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 10/13] bpf: Add migration to sk_reuseport_(kern|md) Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 11/13] bpf: Support BPF_FUNC_get_socket_cookie() for BPF_PROG_TYPE_SK_REUSEPORT Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 12/13] bpf: Call bpf_run_sk_reuseport() for socket migration Kuniyuki Iwashima
2020-12-07 13:24 ` [PATCH v2 bpf-next 13/13] bpf: Test BPF_SK_REUSEPORT_SELECT_OR_MIGRATE Kuniyuki Iwashima
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