Add utility functions

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/util/write_retry.c b/lib/util/write_retry.c
new file mode 100644
index 0000000..637b5d2
--- /dev/null
+++ b/lib/util/write_retry.c
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include <unistd.h>
+#include <errno.h>
+
+#include "util.h"
+
+ssize_t write_retry(int fd, void *data, size_t size)
+{
+	ssize_t ret, total = 0;
+
+	while (size > 0) {
+		ret = write(fd, data, size);
+		if (ret == 0)
+			break;
+		if (ret < 0) {
+			if (errno == EINTR)
+				continue;
+			return -1;
+		}
+
+		data = (char *)data + ret;
+		size -= ret;
+		total += ret;
+	}
+
+	return total;
+}