start dns resolver detection and debugging

Signed-off-by: Jeff Carr <jcarr@wit.com>

bash.go

@@ -54,7 +54,7 @@ func test() error {
 
 func mainBash() {
         if err := test(); err != nil {
-		log.Println(logError, "exit in mainBash()")
+		debug(LogError, "exit in mainBash()")
                 exit(err)
         }
 }

dns.go

@@ -24,7 +24,7 @@ func (h *Host) verifyETC() bool {
 func (h *Host) updateIPs(host string) {
     ips, err := net.LookupIP(host)
         if err != nil {
-                log.Println(logError, "updateIPs failed", err)
+                debug(LogError, "updateIPs failed", err)
         }
         for _, ip := range ips {
                 log.Println(host, ip)

fsnotify.go

@@ -14,7 +14,7 @@ func watchSysClassNet() {
     // Create new watcher.
     watcher, err := fsnotify.NewWatcher()
     if err != nil {
-	    log.Println(logError, "watchSysClassNet() failed:", err)
+	    debug(LogError, "watchSysClassNet() failed:", err)
 	    return
     }
     defer watcher.Close()
@@ -43,7 +43,7 @@ func watchSysClassNet() {
     // Add a path.
     err = watcher.Add("/tmp")
     if err != nil {
-	    log.Println(logError, "watchSysClassNet() watcher.Add() failed:", err)
+	    debug(LogError, "watchSysClassNet() watcher.Add() failed:", err)
 	    return
     }
 

gui.go

@@ -100,6 +100,25 @@ func debugTab(title string) {
 		dumpIPs("www.apple.com")
 	})
 
+	g2 = tab.NewGroup("debugging options")
+
+	// DEBUG flags
+	dbOn := g2.NewCheckbox("turn on debugging (will override all flags below)")
+	dbOn.Custom = func() {
+		DEBUGON = dbOn.B
+	}
+
+	dbNet := g2.NewCheckbox("turn on network debugging)")
+	dbNet.Custom = func() {
+		DEBUGNET = dbNet.B
+	}
+
+	dbProc := g2.NewCheckbox("turn on /proc debugging)")
+	dbProc.Custom = func() {
+		DEBUGPROC = dbProc.B
+	}
+
+	// various timeout settings
 	g2.NewLabel("control panel TTL (in tenths of seconds)")
 	ttl := g2.NewSlider("dnsTTL", 1, 100)
 	ttl.Set(me.dnsTTL * 10)
@@ -115,6 +134,9 @@ func debugTab(title string) {
 		me.dnsTTLsleep = float64(ttl2.I) / 10
 		log.Println("dnsTTLsleep =", me.dnsTTLsleep)
 	}
+
+	g2.Margin()
+	g2.Pad()
 }
 
 func myDefaultExit(n *gui.Node) {

log.go

@@ -8,12 +8,12 @@ import 	(
 
 // various debugging flags
 var logNow bool = true	// useful for active development
-var logError bool = true
-var logWarn bool = false
-var logInfo bool = false
-var logVerbose bool = false
+var LogError bool = true
+var LogProc bool = false // turn on /proc debugging output
 
-var DEBUGOFF bool = true
+var DEBUGON bool = false
+var DEBUGPROC bool = false
+var DEBUGNET bool = false
 
 var SPEW witlog.Spewt
 
@@ -31,12 +31,12 @@ func sleep(a ...any) {
 }
 
 func exit(a ...any) {
-	log.Println(logError, "got to log() exit")
+	debug(LogError, "got to log() exit")
 	witlog.Exit(a...)
 }
 
 func debug(a ...any) {
-	if (DEBUGOFF) {
+	if (! DEBUGON) {
 		return
 	}
 

main.go

@@ -107,9 +107,20 @@ func dnsTTL() {
 
 	if (me.changed) {
 		stamp := time.Now().Format("2006/01/02 15:04:05")
-		log.Println(logError, "Network things changed on", stamp)
+		debug(LogError, "Network things changed on", stamp)
 		updateDNS()
 	}
+
+	processName := getProcessNameByPort(53)
+	fmt.Println("Process with port 53:", processName)
+	/*
+	commPath := filepath.Join("/proc", proc.Name(), "comm")
+	comm, err := ioutil.ReadFile(commPath)
+	if err != nil {
+		return "", err // Error reading the process name
+	}
+	return strings.TrimSpace(string(comm)), nil
+	*/
 }
 
 /*

net.go

@@ -7,8 +7,6 @@ import 	(
 	"strings"
 )
 
-var DEBUGNET bool = false
-
 // this doesn't work
 /*
 func watchNetworkInterfaces() {
@@ -187,6 +185,7 @@ func checkIP(ip *net.IPNet, i net.Interface) bool {
 }
 
 func scanInterfaces() {
+	debug(DEBUGNET, "scanInterfaces() START")
 	me.changed = false
 	ifaces, _ := net.Interfaces()
 	// me.ifnew = ifaces
@@ -230,6 +229,7 @@ func scanInterfaces() {
 	all6 = strings.TrimSpace(all6)
 	me.IPv4.SetText(all4)
 	me.IPv6.SetText(all6)
+	debug(DEBUGNET, "scanInterfaces() END")
 }
 
 // delete network interfaces and ip addresses from the gui

proc.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+func getProcessNameByPort(port int) string {
+	// Convert port to hex string
+	portHex := strconv.FormatInt(int64(port), 16)
+
+	// Function to search /proc/net/tcp or /proc/net/udp
+	searchProcNet := func(file string) string {
+		data, err := ioutil.ReadFile(file)
+		if err != nil {
+			return ""
+		}
+		// debug(DEBUGPROC, "searchProcNet() data:", string(data))
+
+		lines := strings.Split(string(data), "\n")
+		for _, line := range lines {
+			fields := strings.Fields(line)
+			debug(DEBUGPROC, "searchProcNet() portHex:", portHex)
+			if (len(fields) > 9) {
+				debug(DEBUGPROC, "searchProcNet() fields[9]", fields[9])
+			}
+			debug(DEBUGPROC, "searchProcNet() lines:", line)
+			if len(fields) > 1 {
+				parts := strings.Split(fields[1], ":")
+				if len(parts) > 1 {
+					// Convert the hexadecimal string to an integer
+					value, _ := strconv.ParseInt(parts[1], 16, 64)
+					debug(DEBUGPROC, "searchProcNet() value, port =", value, port, "parts[1] =", parts[1])
+					if (port == int(value)) {
+						debug(DEBUGPROC, "searchProcNet() THIS IS THE LINE:", fields)
+						return fields[9]
+					}
+				}
+			}
+		}
+
+		return ""
+	}
+
+	// Search TCP and then UDP
+	inode := searchProcNet("/proc/net/tcp")
+	if inode == "" {
+		inode = searchProcNet("/proc/net/udp")
+	}
+	debug(DEBUGPROC, "searchProcNet() inode =", inode)
+
+	// Search for process with the inode
+	procs, _ := ioutil.ReadDir("/proc")
+	for _, proc := range procs {
+		if !proc.IsDir() {
+			continue
+		}
+
+		fdPath := filepath.Join("/proc", proc.Name(), "fd")
+		fds, err := ioutil.ReadDir(fdPath)
+		if err != nil {
+			continue // Process might have exited; skip it
+		}
+
+		for _, fd := range fds {
+			fdLink, _ := os.Readlink(filepath.Join(fdPath, fd.Name()))
+			var s string
+			s = "socket:["+inode+"]"
+			if strings.Contains(fdLink, "socket:[") {
+				debug(DEBUGPROC, "searchProcNet() fdLink has socket:", fdLink)
+				debug(DEBUGPROC, "searchProcNet() proc.Name() =", proc.Name(), "s =", s)
+			}
+			if strings.Contains(fdLink, "socket:[35452]") {
+				debug(DEBUGPROC, "searchProcNet() found proc.Name() =", proc.Name(), fdLink)
+				return proc.Name()
+			}
+			if strings.Contains(fdLink, "socket:[35450]") {
+				debug(DEBUGPROC, "searchProcNet() found proc.Name() =", proc.Name(), fdLink)
+				return proc.Name()
+			}
+			if strings.Contains(fdLink, "socket:[35440]") {
+				debug(DEBUGPROC, "searchProcNet() found proc.Name() =", proc.Name(), fdLink)
+				return proc.Name()
+			}
+			if strings.Contains(fdLink, "socket:[21303]") {
+				debug(DEBUGPROC, "searchProcNet() found proc.Name() =", proc.Name(), fdLink)
+				// return proc.Name()
+			}
+			if strings.Contains(fdLink, "socket:["+inode+"]") {
+				return proc.Name()
+			}
+		}
+	}
+
+	return ""
+}

rtnetlink.go

@@ -10,7 +10,7 @@ func Example_listLink() {
 	// Dial a connection to the rtnetlink socket
 	conn, err := rtnetlink.Dial(nil)
 	if err != nil {
-		log.Println(logError, "Example_listLink() failed", err)
+		debug(LogError, "Example_listLink() failed", err)
 		return
 	}
 	defer conn.Close()

unix.go

@@ -23,7 +23,7 @@ func Escalate() {
 		cmd.Stderr = os.Stderr
 		err := cmd.Run()
 		if err != nil {
-			log.Println(logError, "exit in Escalate()")
+			debug(LogError, "exit in Escalate()")
 			exit(err)
 		}
 	}
@@ -45,7 +45,7 @@ func DumpPublicDNSZone(zone string) {
 func dumpIPs(host string) {
     ips, err := net.LookupIP(host)
         if err != nil {
-		log.Println(logError, "dumpIPs() failed:", err)
+		debug(LogError, "dumpIPs() failed:", err)
         }
         for _, ip := range ips {
                 log.Println(host, ip)