sctp: implement sender-side procedures for Add Incoming/Outgoing Streams Request Parameter

This patch is to implement Sender-Side Procedures for the Add
Outgoing and Incoming Streams Request Parameter described in
rfc6525 section 5.1.5-5.1.6.

It is also to add sockopt SCTP_ADD_STREAMS in rfc6525 section
6.3.4 for users.

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, 29 insertions, 0 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 45a7c417eb7f..75f35cea4371 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3844,6 +3844,32 @@ out:
 	return retval;
 }
 
+static int sctp_setsockopt_add_streams(struct sock *sk,
+				       char __user *optval,
+				       unsigned int optlen)
+{
+	struct sctp_association *asoc;
+	struct sctp_add_streams params;
+	int retval = -EINVAL;
+
+	if (optlen != sizeof(params))
+		goto out;
+
+	if (copy_from_user(&params, optval, optlen)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	asoc = sctp_id2assoc(sk, params.sas_assoc_id);
+	if (!asoc)
+		goto out;
+
+	retval = sctp_send_add_streams(asoc, &params);
+
+out:
+	return retval;
+}
+
 /* API 6.2 setsockopt(), getsockopt()
  *
  * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -4019,6 +4045,9 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 	case SCTP_RESET_ASSOC:
 		retval = sctp_setsockopt_reset_assoc(sk, optval, optlen);
 		break;
+	case SCTP_ADD_STREAMS:
+		retval = sctp_setsockopt_add_streams(sk, optval, optlen);
+		break;
 	default:
 		retval = -ENOPROTOOPT;
 		break;