diff --git a/source3/lib/sys_rw_data.c b/source3/lib/sys_rw_data.c
index e4f9a16345f..353dbe75c2d 100644
--- a/source3/lib/sys_rw_data.c
+++ b/source3/lib/sys_rw_data.c
@@ -105,3 +105,25 @@ ssize_t write_data(int fd, const void *buffer, size_t n)
 	iov.iov_len = n;
 	return write_data_iov(fd, &iov, 1);
 }
+
+/*
+ * Blocking read n bytes from a fd
+ */
+
+ssize_t read_data(int fd, void *buffer, size_t n)
+{
+	ssize_t nread;
+
+	nread = 0;
+
+	while (nread < n) {
+		ssize_t ret;
+		ret = sys_read(fd, ((char *)buffer) + nread, n - nread);
+		if (ret <= 0) {
+			return ret;
+		}
+		nread += ret;
+	}
+
+	return nread;
+}
diff --git a/source3/lib/sys_rw_data.h b/source3/lib/sys_rw_data.h
index 5d1995b3342..bda3795d051 100644
--- a/source3/lib/sys_rw_data.h
+++ b/source3/lib/sys_rw_data.h
@@ -29,5 +29,6 @@ struct iovec;
 
 ssize_t write_data_iov(int fd, const struct iovec *iov, int iovcnt);
 ssize_t write_data(int fd, const void *buffer, size_t n);
+ssize_t read_data(int fd, void *buffer, size_t n);
 
 #endif