From f2c6faad44fa70cdc8ef80385ca9826bbf0468d9 Mon Sep 17 00:00:00 2001
From: David Anderson <danderson@tailscale.com>
Date: Wed, 1 Apr 2020 09:27:02 -0700
Subject: [PATCH] device: return generic error from Ipc{Get,Set}Operation.

This makes uapi.go's public API conform to Go style in terms
of error types.

Signed-off-by: David Anderson <danderson@tailscale.com>
---
 device/uapi.go | 19 +++++++++++++++----
 go.mod         |  2 +-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/device/uapi.go b/device/uapi.go
index 6cdccd6..1080ca1 100644
--- a/device/uapi.go
+++ b/device/uapi.go
@@ -7,6 +7,7 @@ package device
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -31,7 +32,7 @@ func (s IPCError) ErrorCode() int64 {
 	return s.int64
 }
 
-func (device *Device) IpcGetOperation(socket *bufio.Writer) *IPCError {
+func (device *Device) IpcGetOperation(socket *bufio.Writer) error {
 	lines := make([]string, 0, 100)
 	send := func(line string) {
 		lines = append(lines, line)
@@ -106,7 +107,7 @@ func (device *Device) IpcGetOperation(socket *bufio.Writer) *IPCError {
 	return nil
 }
 
-func (device *Device) IpcSetOperation(socket *bufio.Reader) *IPCError {
+func (device *Device) IpcSetOperation(socket *bufio.Reader) error {
 	scanner := bufio.NewScanner(socket)
 	logError := device.log.Error
 	logDebug := device.log.Debug
@@ -421,10 +422,20 @@ func (device *Device) IpcHandle(socket net.Conn) {
 
 	switch op {
 	case "set=1\n":
-		status = device.IpcSetOperation(buffered.Reader)
+		err = device.IpcSetOperation(buffered.Reader)
+		if err != nil && !errors.As(err, &status) {
+			// should never happen
+			device.log.Error.Println("Invalid UAPI error:", err)
+			status = &IPCError{1}
+		}
 
 	case "get=1\n":
-		status = device.IpcGetOperation(buffered.Writer)
+		err = device.IpcGetOperation(buffered.Writer)
+		if err != nil && !errors.As(err, &status) {
+			// should never happen
+			device.log.Error.Println("Invalid UAPI error:", err)
+			status = &IPCError{1}
+		}
 
 	default:
 		device.log.Error.Println("Invalid UAPI operation:", op)
diff --git a/go.mod b/go.mod
index f4e7b97..c2183e0 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module golang.zx2c4.com/wireguard
 
-go 1.12
+go 1.13
 
 require (
 	golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc