Added generic configuration file

CHANGELOG

@@ -1,5 +1,9 @@
 # Change Log
 
+## [8.1.1] 11/06/2018
+
+* Dynamic IP reconfiguration using `set` command (#1125)
+
 ## [8.1.0] 11/05/2018
 
 * Implemented latency measurement for peers (#445)

VERSION

@@ -1 +1 @@
-8.1.0
+8.1.1

config.darwin.yaml

@@ -0,0 +1,3 @@
+iptool: /sbin/ifconfig
+pmtu: false
+mtu: 1500

config.linux.yaml

@@ -0,0 +1,3 @@
+iptool: /sbin/ip
+pmtu: false
+mtu: 1500

config.windows.yaml

@@ -0,0 +1,5 @@
+iptool: netsh.exe
+taptool: C:\\Program Files\\TAP-Windows\\bin\\tapinstall.exe
+inf_file: C:\\Program Files\\TAP-Windows\\driver\\OemVista.inf
+pmtu: false
+mtu: 1500

lib/conf.go

@@ -0,0 +1,69 @@
+package ptp
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	yaml "gopkg.in/yaml.v2"
+)
+
+type conf struct {
+	IPTool  string `yaml:"iptool"`
+	TAPTool string `yaml:"taptool"`
+	INFFile string `yaml:"inf_file"`
+	MTU     int    `yaml:"mtu"`
+	PMTU    bool   `yaml:"pmtu"`
+}
+
+func (c *conf) readConf(filepath string) error {
+	yamlFile, err := ioutil.ReadFile(filepath)
+	if err != nil {
+		Log(Debug, "Failed to load config: %v", err)
+		c.IPTool = DefaultIPTool
+		c.TAPTool = DefaultTAPTool
+		c.INFFile = DefaultINFFile
+		c.MTU = DefaultMTU
+		c.PMTU = DefaultPMTU
+		return fmt.Errorf("Failed to load configuration file from %s: %s", filepath, err.Error())
+	}
+	err = yaml.Unmarshal(yamlFile, c)
+	if err != nil {
+		return fmt.Errorf("Failed to parse config: %v", err)
+	}
+	return nil
+}
+
+func (c *conf) getIPTool(preset string) string {
+	if preset != "" {
+		return preset
+	}
+	return c.IPTool
+}
+
+func (c *conf) getTAPTool(preset string) string {
+	if preset != "" {
+		return preset
+	}
+	return c.TAPTool
+}
+
+func (c *conf) getINFFile(preset string) string {
+	if preset != "" {
+		return preset
+	}
+	return c.INFFile
+}
+
+func (c *conf) getMTU(preset int) int {
+	if preset != 0 {
+		return preset
+	}
+	return c.MTU
+}
+
+func (c *conf) getPMTU(preset bool) bool {
+	if preset {
+		return preset
+	}
+	return c.PMTU
+}

lib/conf_darwin.go

@@ -0,0 +1,12 @@
+// +build darwin
+
+package ptp
+
+// Platform specific defaults
+const (
+	DefaultIPTool  = "/sbin/ifconfig" // Default network interface configuration tool for Darwin OS
+	DefaultTAPTool = ""               // Default path to TAP configuration tool on Windows OS
+	DefaultINFFile = ""               // Default path to TAP INF file used by Windows OS
+	DefaultMTU     = 1500             // Default MTU value
+	DefaultPMTU    = false            // Default PMTU switch
+)