From 848fd50815066c91baff81bbc28abacf5efbc55f Mon Sep 17 00:00:00 2001
From: mame82 <mame8282@googlemail.com>
Date: Mon, 28 May 2018 14:34:59 +0000
Subject: [PATCH] Fix cli DHCP options, started WiFi config for CLI, wrapped
 wpa_supplicant into service

---
 cli_client/cmd_net.go    |  16 ++--
 cli_client/cmd_wifi.go   | 160 +++++++++++++++++++++++++++++++++++++++
 cli_client/rpc_client.go |  22 ++++++
 dependencies.sh          |   1 +
 notes.txt                |   4 +
 service/wifi.go          | 113 ++++++++++++++++++++++++++-
 6 files changed, 307 insertions(+), 9 deletions(-)
 create mode 100644 cli_client/cmd_wifi.go
 create mode 100644 notes.txt

diff --git a/cli_client/cmd_net.go b/cli_client/cmd_net.go
index d6e421a..49de020 100644
--- a/cli_client/cmd_net.go
+++ b/cli_client/cmd_net.go
@@ -33,7 +33,6 @@ func init(){
 }
 */
 
-// usbCmd represents the usb command
 var netCmd = &cobra.Command{
 	Use:   "NET",
 	Short: "Configure Network settings of ethernet interfaces (including USB ethernet if enabled)",
@@ -147,10 +146,13 @@ func createManualSettings(iface string, ip4 string, mask4 string, disabled bool)
 
 func parseDhcpServerOptions(strOptions []string) (options map[uint32]string, err error) {
 	options = map[uint32]string{}
+
 	for _, strOpt := range strOptions {
 		splOpt := strings.SplitN(strOpt,":", 2)
 		if len(splOpt) == 0 {
-			return nil,errors.New(fmt.Sprintf("Invalid DHCP option: %s\nOption format is \"<DHCPOptionNumber>:[DHCPOptionValue]\"", strOpt))
+			//return nil,errors.New(fmt.Sprintf("Invalid DHCP option: %s\nOption format is \"<DHCPOptionNumber>:[DHCPOptionValue]\"", strOpt))
+			//ignore empty options
+			continue
 		}
 		optNum, err := strconv.Atoi(splOpt[0])
 		if err != nil || optNum < 0 {
@@ -174,10 +176,14 @@ func parseDhcpServerOptions(strOptions []string) (options map[uint32]string, err
 
 func parseDhcpServerRanges(strRanges []string) (ranges []*pb.DHCPServerRange, err error) {
 	ranges = []*pb.DHCPServerRange{}
+	if len(strRanges) == 0 {
+		return nil,errors.New(fmt.Sprintf("Missing DHCP range: At least one range should be provided to allow assigning IP addresses to clients\n"))
+	}
+
 	for _,strRange := range strRanges {
 		splRange := strings.Split(strRange, "|")
 		if len(splRange) != 3 && len(splRange) != 2 {
-			return nil,errors.New(fmt.Sprintf("Invalid DHCP range: %s\nOption format is \"<first IPv4>|<last IPv4>[|leaseTime]\"", strRange))
+			return nil,errors.New(fmt.Sprintf("Invalid DHCP range: %s\nformat is \"<first IPv4>|<last IPv4>[|leaseTime]\"", strRange))
 		}
 
 		if net.ParseIP(splRange[0]) == nil {
@@ -277,6 +283,6 @@ func init() {
 	netSetManualCmd.Flags().StringVarP(&tmpStrNetmask4, "netmask","m", "", "The IPv4 netmask to use for the interface")
 	netSetDHCPServerCmd.Flags().StringVarP(&tmpStrAddress4, "address","a", "", "The IPv4 address to use for the interface")
 	netSetDHCPServerCmd.Flags().StringVarP(&tmpStrNetmask4, "netmask","m", "", "The IPv4 netmask to use for the interface")
-	netSetDHCPServerCmd.Flags().StringSliceVarP(&tmpDHCPSrvRanges, "range", "r",[]string{""}, "A DHCP Server range in form \"<lowest IPv4>|<highest IPv4>[|lease time]\" (the flag could be used multiple times)")
-	netSetDHCPServerCmd.Flags().StringSliceVarP(&tmpDHCPSrvOptions, "option", "o",[]string{""}, "A DHCP Server option in form \"<option number>:<value1|value2>\" (Option values have to be separated by '|' not by ','. The flag could be used multiple times)")
+	netSetDHCPServerCmd.Flags().StringSliceVarP(&tmpDHCPSrvRanges, "range", "r",[]string{}, "A DHCP Server range in form \"<lowest IPv4>|<highest IPv4>[|lease time]\" (the flag could be used multiple times)")
+	netSetDHCPServerCmd.Flags().StringSliceVarP(&tmpDHCPSrvOptions, "option", "o",[]string{}, "A DHCP Server option in form \"<option number>:<value1|value2>\" (Option values have to be separated by '|' not by ','. The flag could be used multiple times)")
 }
diff --git a/cli_client/cmd_wifi.go b/cli_client/cmd_wifi.go
new file mode 100644
index 0000000..f789885
--- /dev/null
+++ b/cli_client/cmd_wifi.go
@@ -0,0 +1,160 @@
+package cli_client
+
+import (
+	"github.com/spf13/cobra"
+	pb "../proto"
+	"fmt"
+	"google.golang.org/grpc/status"
+	"os"
+	"errors"
+	"strings"
+)
+
+//Empty settings used to store cobra flags
+var (
+
+	tmpWifiStrReg         string   = ""
+	tmpWifiStrChannel     uint8   = 0
+	tmpWifiHideSSID       bool     = false
+	tmpWifiDisabled       bool     = false
+	tmpWifiDisableNexmon       bool     = false
+	tmpWifiSSID string = ""
+	tmpWifiPSK string = ""
+
+)
+
+/*
+func init(){
+	//Configure spew for struct deep printing (disable using printer interface for gRPC structs)
+	spew.Config.Indent="\t"
+	spew.Config.DisableMethods = true
+	spew.Config.DisablePointerAddresses = true
+}
+*/
+
+var wifiCmd = &cobra.Command{
+	Use:   "WIFI",
+	Short: "Configure WiFi (spawn Access Point or join WiFi networks)",
+}
+
+var wifiSetCmd = &cobra.Command{
+	Use:   "set",
+	Short: "set WiFi settings",
+	Long: ``,
+}
+
+var wifiSetAPCmd = &cobra.Command{
+	Use:   "ap",
+	Short: "Configure WiFi interface as access point",
+	Long: ``,
+	Run: cobraWifiSetAP,
+}
+
+
+var wifiSetStaCmd = &cobra.Command{
+	Use:   "sta",
+	Short: "Configure WiFi interface to join a network as station",
+	Long: ``,
+	Run: cobraWifiSetSta,
+}
+
+var wifiGetCmd = &cobra.Command{
+	Use:   "get",
+	Short: "get WiFi settings",
+	Long: ``,
+	Run: cobraWifiGet,
+}
+
+func cobraWifiGet(cmd *cobra.Command, args []string) {
+	return
+}
+
+func cobraWifiSetAP(cmd *cobra.Command, args []string) {
+	settings, err := createWifiAPSettings(tmpWifiStrChannel, tmpWifiStrReg, tmpWifiSSID, tmpWifiPSK, tmpWifiHideSSID, tmpWifiDisableNexmon, tmpWifiDisabled)
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+
+		os.Exit(-1) //exit with error
+		return
+	}
+
+
+	fmt.Printf("Deploying WiFi inteface settings:\n\t%v\n", settings)
+
+	err = ClientDeployWifiSettings(StrRemoteHost, StrRemotePort, settings)
+	if err != nil {
+		fmt.Println(status.Convert(err).Message())
+		os.Exit(-1) //exit with error
+	}
+
+
+	return
+}
+
+func cobraWifiSetSta(cmd *cobra.Command, args []string) {
+
+	return
+}
+
+func createWifiAPSettings(channel uint8, reg string, strSSID string, strPSK string, hideSsid bool, nexmon bool, disabled bool) (settings *pb.WiFiSettings, err error) {
+
+
+	if channel < 1 || channel > 14 {
+		return nil,errors.New(fmt.Sprintf("Only 2.4GHz channels between 1 and 14 are supported, but '%d' was given\n", channel))
+	}
+
+
+	if len(reg) != 2 {
+		return nil,errors.New(fmt.Sprintf("Regulatory domain has to consist of two uppercase letters (ISO/IEC 3166-1 alpha2), but '%s' was given\n", reg))
+	}
+	reg = strings.ToUpper(reg)
+
+
+	if len(strSSID) < 1 || len(strSSID) > 32 {
+		return nil,errors.New(fmt.Sprintf("SSID has to consist of 1 to 32 ASCII letters (even if hidden), but '%s' was given\n", strSSID))
+	}
+
+	if len(strPSK) > 0 && len(strPSK) < 8 {
+		return nil,errors.New(fmt.Sprintf("A non-empty PSK implies WPA2 and has to have a minimum of 8 characters, but given PSK has '%d' charactres\n", len(strPSK)))
+	}
+
+	settings = &pb.WiFiSettings{
+		Mode: pb.WiFiSettings_AP,
+		AuthMode: pb.WiFiSettings_OPEN,
+		Disabled: disabled,
+		Reg: reg,
+		ApChannel: uint32(channel),
+		ApHideSsid: hideSsid,
+		BssCfgAP: &pb.BSSCfg{
+			SSID: strSSID,
+			PSK: strPSK,
+		},
+		DisableNexmon: !nexmon,
+		BssCfgClient: nil, //not needed
+	}
+
+	if len(strPSK) > 0 {
+		settings.AuthMode = pb.WiFiSettings_WPA2_PSK //if PSK is given use WPA2
+	}
+
+
+	return settings, err
+}
+
+
+func init() {
+	rootCmd.AddCommand(wifiCmd)
+	wifiCmd.AddCommand(wifiGetCmd)
+	wifiCmd.AddCommand(wifiSetCmd)
+	wifiSetCmd.AddCommand(wifiSetAPCmd)
+	wifiSetCmd.AddCommand(wifiSetStaCmd)
+
+	wifiSetCmd.PersistentFlags().StringVarP(&tmpWifiStrReg, "reg","r", "US", "Sets the regulatory domain according to ISO/IEC 3166-1 alpha2")
+	wifiSetCmd.PersistentFlags().BoolVarP(&tmpWifiDisabled, "disable","d", false, "The flag disables the WiFi interface (omitting the flag enables the interface")
+	wifiSetCmd.PersistentFlags().BoolVarP(&tmpWifiDisableNexmon, "nonexmon","n", false, "Don't use the modified nexmon firmware")
+	wifiSetCmd.PersistentFlags().StringVarP(&tmpWifiSSID, "ssid","s", "", "The SSID to use for an Access Point or to join as station")
+	wifiSetCmd.PersistentFlags().StringVarP(&tmpWifiPSK, "psk","k", "", "The Pre-Shared-Key to use for the Access Point (if empty, an OPEN AP is created) or for the network")
+
+	wifiSetAPCmd.Flags().Uint8VarP(&tmpWifiStrChannel, "channel","c", 1, "The WiFi channel to use for the Access Point")
+	wifiSetAPCmd.Flags().BoolVarP(&tmpWifiHideSSID, "hide","x", false, "Hide the SSID of the Access Point")
+}
diff --git a/cli_client/rpc_client.go b/cli_client/rpc_client.go
index b2a3f06..24b9d41 100644
--- a/cli_client/rpc_client.go
+++ b/cli_client/rpc_client.go
@@ -139,6 +139,28 @@ func ClientDeployEthernetInterfaceSettings(host string, port string, settings *p
 
 }
 
+func ClientDeployWifiSettings(host string, port string, settings *pb.WiFiSettings) (err error) {
+	// Set up a connection to the server.
+	address := host + ":" + port
+	//log.Printf("Connecting %s ...", address)
+	connection, err := grpc.Dial(address, grpc.WithInsecure())
+	if err != nil {
+		log.Fatalf("Could not connect to P4wnP1 RPC server: %v", err)
+	}
+	defer connection.Close()
+
+	rpcClient := pb.NewP4WNP1Client(connection)
+
+	// Contact the server
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second * 30)
+	defer cancel()
+
+	_,err = rpcClient.DeployWifiSettings(ctx, settings)
+
+
+	return err
+}
+
 /*
 func ClientDisconnectServer(cancel context.CancelFunc, connection *grpc.ClientConn) error {
 	defer connection.Close()
diff --git a/dependencies.sh b/dependencies.sh
index dd1bef0..1268b47 100755
--- a/dependencies.sh
+++ b/dependencies.sh
@@ -29,3 +29,4 @@ sudo pip install pydispatcher
 
 
 sudo update-rc.d dhcpcd disable
+sudo update-rc.d dnsmasq disable
diff --git a/notes.txt b/notes.txt
new file mode 100644
index 0000000..1b43122
--- /dev/null
+++ b/notes.txt
@@ -0,0 +1,4 @@
+- global dnsmasq service needs to be stopped, in order to avoid overwriting resolv.conf with configuration of local loopback interface (nameserver 127.0.0.1)
+- global dhcpcd service needs to be stopped
+- gloabel hostapd service needs to be stopped
+- global wpa_supplicant service needs to be stopped
diff --git a/service/wifi.go b/service/wifi.go
index 4f8e87a..5a475aa 100644
--- a/service/wifi.go
+++ b/service/wifi.go
@@ -14,6 +14,8 @@ import (
 	"strconv"
 	"syscall"
 	"time"
+	"bufio"
+	"io"
 )
 
 const (
@@ -32,6 +34,10 @@ const (
 	WiFiAuthMode_UNSUPPORTED
 )
 
+const (
+	WPA_SUPPLICANT_CONNECT_TIMEOUT = time.Second * 10
+)
+
 type BSS struct {
 	SSID string
 	BSSID net.HardwareAddr
@@ -127,7 +133,7 @@ func DeployWifiSettings(ws *pb.WiFiSettings) (err error) {
 			err = WifiCreateWpaSupplicantConfigFile(ws.BssCfgClient.SSID, ws.BssCfgClient.PSK, confFileWpaSupplicant(wifi_if_name))
 			if err != nil { return err }
 			//ToDo: proper error handling, in case connection not possible
-			err = wifiStartWpaSupplicant(wifi_if_name)
+			err = wifiStartWpaSupplicant2(wifi_if_name, WPA_SUPPLICANT_CONNECT_TIMEOUT)
 			if err != nil { return err }
 		}
 
@@ -203,6 +209,8 @@ func wifiCreateWpaSupplicantConfString(ssid string, psk string) (config string,
 		return "",errors.New(fmt.Sprintf("Error craeting wpa_supplicant.conf for SSID '%s' with PSK '%s': %s", ssid, psk, string(cres)))
 	}
 	config = string(cres)
+	config = "ctrl_interface=/run/wpa_supplicant\n" + config
+
 
 	return
 }
@@ -307,7 +315,9 @@ func wifiStartHostapd(nameIface string) (err error) {
 	//We use the run command and allow hostapd to daemonize
 	proc := exec.Command("/usr/sbin/hostapd", "-B", "-P", pidFileHostapd(nameIface), "-f", logFileHostapd(nameIface), confpath)
 	err = proc.Run()
-	if err != nil { return err}
+	if err != nil {
+		return errors.New(fmt.Sprintf("Error starting hostapd '%v'", err))
+	}
 
 
 	log.Printf("... hostapd for interface '%s' started\n", nameIface)
@@ -358,11 +368,11 @@ func wifiStartWpaSupplicant(nameIface string) (err error) {
 
 	confpath := confFileWpaSupplicant(nameIface)
 
-	//stop hostapd if already running
+	//stop wpa_supplicant if already running
 	wifiStopWpaSupplicant(nameIface)
 
 
-	//We use the run command and allow hostapd to daemonize
+	//We use the run command and allow wpa_supplicant to daemonize
 	//wpa_supplicant -P /tmp/wpa_supplicant.pid -i wlan0 -c /tmp/wpa_supplicant.conf -B
 	proc := exec.Command("/sbin/wpa_supplicant", "-B", "-P", pidFileWpaSupplicant(nameIface), "-f", logFileWpaSupplicant(nameIface), "-c", confpath, "-i", nameIface)
 	err = proc.Run()
@@ -373,6 +383,101 @@ func wifiStartWpaSupplicant(nameIface string) (err error) {
 	return nil
 }
 
+func wifiWpaSupplicantOutParser(chanResult chan string, reader *bufio.Reader) {
+	log.Println("... Start monitoring wpa_supplicant output")
+
+	for {
+		line, _, err := reader.ReadLine()
+		if err != nil {
+			//in case wpa_supplicant is killed, we should land here, which ends the goroutine
+			if err != io.EOF {
+				log.Printf("Can't read wpa_supplicant output: %s\n", err)
+			}
+
+			break
+		}
+		strLine := string(line)
+
+		//fmt.Printf("Read:\n%s\n", strLine)
+
+		switch {
+		case strings.Contains(strLine, "WRONG_KEY"):
+			log.Printf("Seems the provided PSK doesn't match\n")
+			chanResult <- "WRONG_KEY"
+			break
+		case strings.Contains(strLine, "CTRL-EVENT-CONNECTED"):
+			log.Printf("Connected to target network\n")
+			chanResult <- "CONNECTED"
+			break // stop loop
+		}
+	}
+	log.Println("... stopped monitoring wpa_supplicant output")
+}
+
+func wifiStartWpaSupplicant2(nameIface string, timeout time.Duration) (err error) {
+	log.Printf("Starting wpa_supplicant for interface '%s'...\n", nameIface)
+
+	//check if interface is valid
+	if_exists,_ := CheckInterfaceExistence(nameIface)
+	if !if_exists {
+		return errors.New(fmt.Sprintf("The given interface '%s' doesn't exist", nameIface))
+	}
+
+	if !wifiWpaSupplicantAvailable() {
+		return errors.New("wpa_supplicant seems to be missing, please install it")
+	}
+
+	confpath := confFileWpaSupplicant(nameIface)
+
+	//stop wpa_supplicant if already running
+	wifiStopWpaSupplicant(nameIface)
+
+
+	//we monitor output of wpa_supplicant till we are connected, fail due to wrong PSK or timeout is reached
+	proc := exec.Command("/sbin/wpa_supplicant",  "-P", pidFileWpaSupplicant(nameIface), "-c", confpath, "-i", nameIface)
+
+	wpa_stdout, err := proc.StdoutPipe()
+	if err != nil { return err}
+
+	err = proc.Start()
+	if err != nil { return err}
+
+	//result channel
+	wpa_res := make(chan string, 1)
+	//start output parser
+	wpa_stdout_reader := bufio.NewReader(wpa_stdout)
+
+	go wifiWpaSupplicantOutParser(wpa_res, wpa_stdout_reader)
+
+	//analyse output
+	select {
+		case res := <-wpa_res:
+			if strings.Contains(res, "CONNECTED") {
+				//We could return success and keep wpa_supplicant running
+				log.Println("... connected to given WiFi network, wpa_supplicant running")
+				return nil
+			}
+			if strings.Contains(res, "WRONG_KEY") {
+				//we stop wpa_supplicant and return err
+				log.Println("... seems the wrong PSK wwas provided for the given WiFi network, stopping wpa_supplicant ...")
+				//wifiStopWpaSupplicant(nameIface)
+				log.Println("... killing wpa_supplicant")
+				proc.Process.Kill()
+				return errors.New("Wrong PSK")
+			}
+		case <- time.After(timeout):
+			//we stop wpa_supplicant and return err
+			log.Println("... wpa_supplicant reached timeout without beeing able to connect to given network")
+			log.Println("... killing wpa_supplicant")
+			//wifiStopWpaSupplicant(nameIface)
+			proc.Process.Kill()
+			return errors.New("TIMEOUT REACHED")
+	}
+
+
+	return nil
+}
+
 
 func wifiStopWpaSupplicant(nameIface string) (err error) {
 	log.Printf("... stop running wpa_supplicant processes for interface '%s'\n", nameIface)