1 files changed, 55 insertions, 0 deletions
diff --git a/arch/um/drivers/slip_common.c b/arch/um/drivers/slip_common.c
new file mode 100644
index 000000000..20fe4f427
--- /dev/null
+++ b/arch/um/drivers/slip_common.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <string.h>
+#include "slip_common.h"
+#include <net_user.h>
+
+int slip_proto_read(int fd, void *buf, int len, struct slip_proto *slip)
+{
+	int i, n, size, start;
+
+	if(slip->more > 0){
+		i = 0;
+		while(i < slip->more){
+			size = slip_unesc(slip->ibuf[i++], slip->ibuf,
+					  &slip->pos, &slip->esc);
+			if(size){
+				memcpy(buf, slip->ibuf, size);
+				memmove(slip->ibuf, &slip->ibuf[i],
+					slip->more - i);
+				slip->more = slip->more - i;
+				return size;
+			}
+		}
+		slip->more = 0;
+	}
+
+	n = net_read(fd, &slip->ibuf[slip->pos],
+		     sizeof(slip->ibuf) - slip->pos);
+	if(n <= 0)
+		return n;
+
+	start = slip->pos;
+	for(i = 0; i < n; i++){
+		size = slip_unesc(slip->ibuf[start + i], slip->ibuf,&slip->pos,
+				  &slip->esc);
+		if(size){
+			memcpy(buf, slip->ibuf, size);
+			memmove(slip->ibuf, &slip->ibuf[start+i+1],
+				n - (i + 1));
+			slip->more = n - (i + 1);
+			return size;
+		}
+	}
+	return 0;
+}
+
+int slip_proto_write(int fd, void *buf, int len, struct slip_proto *slip)
+{
+	int actual, n;
+
+	actual = slip_esc(buf, slip->obuf, len);
+	n = net_write(fd, slip->obuf, actual);
+	if(n < 0)
+		return n;
+	else return len;
+}