sctp: add SCTP_CURRENT_ASSOC for SCTP_STREAM_SCHEDULER_VALUE sockopt

SCTP_STREAM_SCHEDULER_VALUE is a special one, as its value is not
save in sctp_sock, but only in asoc. So only SCTP_CURRENT_ASSOC
reserved assoc_id can be used in sctp_setsockopt_scheduler_value.

This patch adds SCTP_CURRENT_ASOC support for
SCTP_STREAM_SCHEDULER_VALUE.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/socket.c

@@ -4211,8 +4211,8 @@ static int sctp_setsockopt_scheduler_value(struct sock *sk,
 					   char __user *optval,
 					   unsigned int optlen)
 {
-	struct sctp_association *asoc;
 	struct sctp_stream_value params;
+	struct sctp_association *asoc;
 	int retval = -EINVAL;
 
 	if (optlen < sizeof(params))
@@ -4225,11 +4225,24 @@ static int sctp_setsockopt_scheduler_value(struct sock *sk,
 	}
 
 	asoc = sctp_id2assoc(sk, params.assoc_id);
-	if (!asoc)
+	if (!asoc && params.assoc_id != SCTP_CURRENT_ASSOC &&
+	    sctp_style(sk, UDP))
 		goto out;
 
-	retval = sctp_sched_set_value(asoc, params.stream_id,
-				      params.stream_value, GFP_KERNEL);
+	if (asoc) {
+		retval = sctp_sched_set_value(asoc, params.stream_id,
+					      params.stream_value, GFP_KERNEL);
+		goto out;
+	}
+
+	retval = 0;
+
+	list_for_each_entry(asoc, &sctp_sk(sk)->ep->asocs, asocs) {
+		int ret = sctp_sched_set_value(asoc, params.stream_id,
+					       params.stream_value, GFP_KERNEL);
+		if (ret && !retval) /* try to return the 1st error. */
+			retval = ret;
+	}
 
 out:
 	return retval;