sctp: fix missing send up SCTP_SENDER_DRY_EVENT when subscribe it (94912301) · Commits · 戴 / test

We forgot to send up SCTP_SENDER_DRY_EVENT notification when user app subscribes to this event, and there is no data to be sent or retransmit. This is required by the Socket API and used by the DTLS/SCTP implementation. Reported-by:

Michael Tüxen <Michael.Tuexen@lurchi.franken.de> Signed-off-by:

Wei Yongjun <yjwei@cn.fujitsu.com> Tested-by:

Robin Seggelmann <seggelmann@fh-muenster.de> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sctp/socket.c

+23 −0

Original line number	Diff line number	Diff line
		@@ -2073,10 +2073,33 @@ static int sctp_setsockopt_disable_fragments(struct sock *sk,
		static int sctp_setsockopt_events(struct sock sk, char __user optval,
		unsigned int optlen)
		{
		struct sctp_association *asoc;
		struct sctp_ulpevent *event;

		if (optlen > sizeof(struct sctp_event_subscribe))
		return -EINVAL;
		if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen))
		return -EFAULT;

		/*
		* At the time when a user app subscribes to SCTP_SENDER_DRY_EVENT,
		* if there is no data to be sent or retransmit, the stack will
		* immediately send up this notification.
		*/
		if (sctp_ulpevent_type_enabled(SCTP_SENDER_DRY_EVENT,
		&sctp_sk(sk)->subscribe)) {
		asoc = sctp_id2assoc(sk, 0);

		if (asoc && sctp_outq_is_empty(&asoc->outqueue)) {
		event = sctp_ulpevent_make_sender_dry_event(asoc,
		GFP_ATOMIC);
		if (!event)
		return -ENOMEM;

		sctp_ulpq_tail_event(&asoc->ulpq, event);
		}
		}

		return 0;
		}

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