sctp: add SCTP_PR_SUPPORTED on sctp sockopt

According to section 4.5 of rfc7496, prsctp_enable should be per asoc.
We will add prsctp_enable to both asoc and ep, and replace the places
where it used net.sctp->prsctp_enable with asoc->prsctp_enable.

ep->prsctp_enable will be initialized with net.sctp->prsctp_enable, and
asoc->prsctp_enable will be initialized with ep->prsctp_enable. We can
also modify it's value through sockopt SCTP_PR_SUPPORTED.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 80 insertions, 0 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index cdabbd8219b1..7460ddebd9ce 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3661,6 +3661,39 @@ static int sctp_setsockopt_recvnxtinfo(struct sock *sk,
 	return 0;
 }
 
+static int sctp_setsockopt_pr_supported(struct sock *sk,
+					char __user *optval,
+					unsigned int optlen)
+{
+	struct sctp_assoc_value params;
+	struct sctp_association *asoc;
+	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.assoc_id);
+	if (asoc) {
+		asoc->prsctp_enable = !!params.assoc_value;
+	} else if (!params.assoc_id) {
+		struct sctp_sock *sp = sctp_sk(sk);
+
+		sp->ep->prsctp_enable = !!params.assoc_value;
+	} else {
+		goto out;
+	}
+
+	retval = 0;
+
+out:
+	return retval;
+}
+
 /* API 6.2 setsockopt(), getsockopt()
  *
  * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -3821,6 +3854,9 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 	case SCTP_RECVNXTINFO:
 		retval = sctp_setsockopt_recvnxtinfo(sk, optval, optlen);
 		break;
+	case SCTP_PR_SUPPORTED:
+		retval = sctp_setsockopt_pr_supported(sk, optval, optlen);
+		break;
 	default:
 		retval = -ENOPROTOOPT;
 		break;
@@ -6166,6 +6202,47 @@ static int sctp_getsockopt_recvnxtinfo(struct sock *sk,	int len,
 	return 0;
 }
 
+static int sctp_getsockopt_pr_supported(struct sock *sk, int len,
+					char __user *optval,
+					int __user *optlen)
+{
+	struct sctp_assoc_value params;
+	struct sctp_association *asoc;
+	int retval = -EFAULT;
+
+	if (len < sizeof(params)) {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	len = sizeof(params);
+	if (copy_from_user(&params, optval, len))
+		goto out;
+
+	asoc = sctp_id2assoc(sk, params.assoc_id);
+	if (asoc) {
+		params.assoc_value = asoc->prsctp_enable;
+	} else if (!params.assoc_id) {
+		struct sctp_sock *sp = sctp_sk(sk);
+
+		params.assoc_value = sp->ep->prsctp_enable;
+	} else {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	if (put_user(len, optlen))
+		goto out;
+
+	if (copy_to_user(optval, &params, len))
+		goto out;
+
+	retval = 0;
+
+out:
+	return retval;
+}
+
 static int sctp_getsockopt(struct sock *sk, int level, int optname,
 			   char __user *optval, int __user *optlen)
 {
@@ -6319,6 +6396,9 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname,
 	case SCTP_RECVNXTINFO:
 		retval = sctp_getsockopt_recvnxtinfo(sk, len, optval, optlen);
 		break;
+	case SCTP_PR_SUPPORTED:
+		retval = sctp_getsockopt_pr_supported(sk, len, optval, optlen);
+		break;
 	default:
 		retval = -ENOPROTOOPT;
 		break;