stuff? stuff!

config.json

@@ -0,0 +1,18 @@
+// This is JSON. But with comments! They start with "//" (without the quotes)
+{
+	// The file(s) to watch. If no given file contains the
+	// signature and key in the keyfile, the screen is locked.
+	// You can use shell-replacemants like * and ?
+	"Lockfile": "/dev/sd??",
+	
+	// The file containing the key.
+	"Keyfile": "usblocker.key",
+	
+	// The location of the xlock binary.
+	"Xlock_path": "/usr/bin/xlock",
+	
+	// Exclude possible lockfiles, if they contain the wrong
+	// signature or no signature at all.
+	"Blacklist_devices": true
+}
+

usblocker.go

@@ -1,15 +1,39 @@
 package main
 
 import (
+	//"code.google.com/p/gcfg"
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"time"
 )
 
+type Configuration struct {
+	Lockfile          string
+	Keyfile           string
+	Xlock_path        string
+	Blacklist_devices bool
+}
+
 var VERSION = "v0.1.0"
+var CONFIGFILE = "config.json"
+
+// Default configuration
+var cfg = Configuration{
+	Lockfile:          "/dev/sd??",
+	Keyfile:           "usblocker.key",
+	Xlock_path:        "/bin/xlock",
+	Blacklist_devices: true,
+}
+
+var FIRSTRUN = true
+var cmd = exec.Command("")
 
 /* Shows the help message
  */
@@ -17,12 +41,12 @@ func ShowHelp() {
 	fmt.Println("Watches a device and locks the screen if the device is missing.")
 	fmt.Println()
 	fmt.Println("Usage:")
-	fmt.Println("  usblocker run:     Start USBLocker.")
+	fmt.Println("  usblocker start:   Start USBLocker.")
 	//fmt.Println("  usblocker daemon:  Runs in background.")
 	//fmt.Println("  usblocker create:  Prepares a device for usage with USBLocker.")
 }
 
-/*
+/* Shows the message of the day
  */
 func ShowMOTD() {
 	fmt.Println("Welcome to USBLocker ", VERSION)
@@ -42,74 +66,81 @@ func WatcherUnlocked(device string) {
 		time.Sleep(time.Duration(1) * time.Second)
 	}
 	log.Println("Locked")
-	var args []string
-	args = append(args, "-nolock") // Fix for... something. First passed argument keeps beeing ignored, for whatever reason.
-	//args = append(args, "-info")
-	//args = append(args, "")
-	args = append(args, "-mode")
-	args = append(args, "blank")
-	//log.Println(args)
-	var attr os.ProcAttr
-	lpid, err := os.StartProcess("/usr/bin/xlock", args, &attr)
+	cmd = exec.Command("/usr/bin/xlock", "-mode", "blank")
+	err := cmd.Start()
 	if err != nil {
 		log.Fatal("Error: ", err)
 	}
-	WatcherLocked(lpid)
+
+	WatcherLocked()
 }
 
 /* Watcher for locked state / no device
  */
-func WatcherLocked(lpid *os.Process) {
-	var passphrase string // TEH KEY!!1!
-	var devices []string  // list of devices
-	var lfile *os.File    // device file
-	ldev := ""            // device file name
-	version := "v0"       // version string
-
-	var passtest []byte
-	for i := 0; i < 1024; i++ {
-		passtest = append(passtest, 0)
-	}
+func WatcherLocked() {
+	var passphrase string             // the key
+	var passtest = make([]byte, 1024) // slice for testing the passphrase
+	var devices []string              // list of devices
+	var devblacklist []string         // blacklist of devices
+	var lfile *os.File                // device file
+	ldev := ""                        // device file name
+	lfileversion := "v1"              // version string
 
 	// Set the passphrase
 	passphrase = "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"
 
 	for {
 		var err error
-		devices, err = filepath.Glob("/dev/?d?1")
+		devices, err = filepath.Glob(cfg.Lockfile)
 		if err != nil {
-			log.Fatal("Error while getting list of aviable devices (/dev/?d?1):", err)
+			log.Fatal("Error while getting list of aviable devices ", cfg.Lockfile, ":", err)
+		}
+		if len(devices) == 0 {
+			log.Fatal("Not found: ", cfg.Lockfile)
 		}
 
 		// Search lock device
-		for i := range devices {
-			log.Println("Checking", devices[i], "for usblocker data...")
-			lfile, err = os.Open(devices[i])
+		for _, device := range devices {
+			log.Println("Checking", device, "for usblocker data...")
+			lfile, err = os.Open(device)
 			if err != nil {
 				log.Fatal("Error while opening the device file:", err)
 			}
 			// Check for magic string
-			magictest := []byte("         ")
+			magictest := make([]byte, 9)
 			length, err := lfile.Read(magictest)
 			if err != nil {
 				log.Fatal("Error while reading the device file:", err)
 				_ = lfile.Close()
 			}
 			if length == 9 && string(magictest) == "usblocker" {
-				ldev = devices[i]
+				ldev = device
 				break
+			} else {
+				if cfg.Blacklist_devices && FIRSTRUN {
+					if len(devblacklist) == 0 {
+						devblacklist = append(devblacklist, device)
+					} else {
+						for _, v := range devblacklist {
+							if v != device {
+								devblacklist = append(devblacklist, device)
+							}
+						}
+					}
+					FIRSTRUN = false
+				}
 			}
 		}
 
 		// Check lockdev version
 		if ldev != "" {
 			log.Println("Checking", ldev, "for right version...")
-			versiontest := []byte("       ")
+			versiontest := make([]byte, 7)
 			length, err := lfile.Read(versiontest)
 			if err != nil {
 				log.Fatal("Error while reading the device file:", err)
 			}
-			if length == 7 && strings.HasPrefix(string(versiontest), version) {
+			if length == 7 && strings.HasPrefix(string(versiontest), lfileversion) {
 				log.Println("Checking passphrase...")
 				length, err := lfile.Read(passtest)
 				_ = lfile.Close()
@@ -119,9 +150,9 @@ func WatcherLocked(lpid *os.Process) {
 				if length == 1024 && string(passtest) == passphrase {
 					// And finally: UNLOCK!
 					log.Println("Unlocked")
-					if lpid != nil {
-						lpid.Kill()
-						_, _ = lpid.Wait()
+					if cmd.Process != nil {
+						cmd.Process.Kill()
+						_ = cmd.Wait()
 					}
 					WatcherUnlocked(ldev)
 				}
@@ -136,25 +167,47 @@ func WatcherLocked(lpid *os.Process) {
  */
 func main() {
 	// Determining what to do
-	if len(os.Args) == 1 {
+	if len(os.Args) < 2 {
 		ShowHelp()
 		return
 	}
 	switch os.Args[1] {
-	case "run":
+	case "start":
 	//case "daemon":
 	//	log.Fatal("Not yet implemented. Probably won't be implemented anyway, go doesn't seem to support forking...")
 	case "create":
 		log.Fatal("Not yet implemented.")
 	default:
 		ShowHelp()
+		return
 	}
 
 	// Check for root
 	if os.Getuid() != 0 {
-		log.Fatal("YU NO GOT ROOT??")
+		log.Fatal("Y U NO GOT ROOT??")
+	}
+
+	// Get configuration from file config.json
+	b, err := ioutil.ReadFile(CONFIGFILE)
+	if err != nil {
+		log.Println("Cannot read configuration file:", err)
+		log.Println("Using default configuration")
+	} else {
+		re := regexp.MustCompile("(?m)^\\s*//.*$")
+		jdata := re.ReplaceAllString(string(b), "")
+		err = json.Unmarshal([]byte(jdata), &cfg)
+		if err != nil {
+			log.Fatal("Failed to get configuration from json:", err)
+		}
+	}
+
+	// Check for xlock
+	_, err = os.Stat(cfg.Xlock_path)
+	if err != nil {
+		os.Stdout.Write([]byte("Is xlock installed and the right path set in config.json?\n"))
+		log.Fatal("Stat for ", cfg.Xlock_path, " failed:", err)
 	}
 
 	ShowMOTD()
-	WatcherLocked(nil)
+	WatcherLocked()
 }