diff options
| author | Xin Long <lucien.xin@gmail.com> | 2024-07-01 13:48:49 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-07-03 09:45:39 +0100 |
| commit | cda91d5b911a5a168a1c6e6917afda43b0e458c8 (patch) | |
| tree | 59344614b873294a6a7068fa2f3e2a72add5681b /net/sctp | |
| parent | 2e3ed20c17e719cbe7b13feaa3e7c46cf6a85887 (diff) | |
sctp: cancel a blocking accept when shutdown a listen socket
As David Laight noticed,
"In a multithreaded program it is reasonable to have a thread blocked in
accept(). With TCP a subsequent shutdown(listen_fd, SHUT_RDWR) causes
the accept to fail. But nothing happens for SCTP."
sctp_disconnect() is eventually called when shutdown a listen socket,
but nothing is done in this function. This patch sets RCV_SHUTDOWN
flag in sk->sk_shutdown there, and adds the check (sk->sk_shutdown &
RCV_SHUTDOWN) to break and return in sctp_accept().
Note that shutdown() is only supported on TCP-style SCTP socket.
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/socket.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index c009383369b2..32f76f1298da 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4834,10 +4834,14 @@ int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr, return sctp_connect(sock->sk, uaddr, addr_len, flags); } -/* FIXME: Write comments. */ +/* Only called when shutdown a listening SCTP socket. */ static int sctp_disconnect(struct sock *sk, int flags) { - return -EOPNOTSUPP; /* STUB */ + if (!sctp_style(sk, TCP)) + return -EOPNOTSUPP; + + sk->sk_shutdown |= RCV_SHUTDOWN; + return 0; } /* 4.1.4 accept() - TCP Style Syntax @@ -4866,7 +4870,8 @@ static struct sock *sctp_accept(struct sock *sk, struct proto_accept_arg *arg) goto out; } - if (!sctp_sstate(sk, LISTENING)) { + if (!sctp_sstate(sk, LISTENING) || + (sk->sk_shutdown & RCV_SHUTDOWN)) { error = -EINVAL; goto out; } @@ -9393,7 +9398,8 @@ static int sctp_wait_for_accept(struct sock *sk, long timeo) } err = -EINVAL; - if (!sctp_sstate(sk, LISTENING)) + if (!sctp_sstate(sk, LISTENING) || + (sk->sk_shutdown & RCV_SHUTDOWN)) break; err = 0; |