sctp: add SCTP_PR_STREAM_STATUS sockopt for prsctp

Before when implementing sctp prsctp, SCTP_PR_STREAM_STATUS wasn't
added, as it needs to save abandoned_(un)sent for every stream.

After sctp stream reconf is added in sctp, assoc has structure
sctp_stream_out to save per stream info.

This patch is to add SCTP_PR_STREAM_STATUS by putting the prsctp
per stream statistics into sctp_stream_out.

v1->v2:
  fix an indent issue.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 0 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index ccc08fc39722..6489446925e6 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6576,6 +6576,61 @@ out:
 	return retval;
 }
 
+static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
+					   char __user *optval,
+					   int __user *optlen)
+{
+	struct sctp_stream_out *streamout;
+	struct sctp_association *asoc;
+	struct sctp_prstatus params;
+	int retval = -EINVAL;
+	int policy;
+
+	if (len < sizeof(params))
+		goto out;
+
+	len = sizeof(params);
+	if (copy_from_user(&params, optval, len)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	policy = params.sprstat_policy;
+	if (policy & ~SCTP_PR_SCTP_MASK)
+		goto out;
+
+	asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
+	if (!asoc || params.sprstat_sid >= asoc->stream->outcnt)
+		goto out;
+
+	streamout = &asoc->stream->out[params.sprstat_sid];
+	if (policy == SCTP_PR_SCTP_NONE) {
+		params.sprstat_abandoned_unsent = 0;
+		params.sprstat_abandoned_sent = 0;
+		for (policy = 0; policy <= SCTP_PR_INDEX(MAX); policy++) {
+			params.sprstat_abandoned_unsent +=
+				streamout->abandoned_unsent[policy];
+			params.sprstat_abandoned_sent +=
+				streamout->abandoned_sent[policy];
+		}
+	} else {
+		params.sprstat_abandoned_unsent =
+			streamout->abandoned_unsent[__SCTP_PR_INDEX(policy)];
+		params.sprstat_abandoned_sent =
+			streamout->abandoned_sent[__SCTP_PR_INDEX(policy)];
+	}
+
+	if (put_user(len, optlen) || copy_to_user(optval, &params, len)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	retval = 0;
+
+out:
+	return retval;
+}
+
 static int sctp_getsockopt_reconfig_supported(struct sock *sk, int len,
 					      char __user *optval,
 					      int __user *optlen)
@@ -6825,6 +6880,10 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname,
 		retval = sctp_getsockopt_pr_assocstatus(sk, len, optval,
 							optlen);
 		break;
+	case SCTP_PR_STREAM_STATUS:
+		retval = sctp_getsockopt_pr_streamstatus(sk, len, optval,
+							 optlen);
+		break;
 	case SCTP_RECONFIG_SUPPORTED:
 		retval = sctp_getsockopt_reconfig_supported(sk, len, optval,
 							    optlen);