Reduce PID finding retries and simply proc interface on linux

network/state/system_linux.go

@@ -13,16 +13,14 @@ var (
 	getUDP4Table = proc.GetUDP4Table
 	getUDP6Table = proc.GetUDP6Table
 
-	lookupTries     = 20 // With a max wait of 5ms, this amounts to up to 100ms.
-	fastLookupTries = 2
-
-	baseWaitTime = 3 * time.Millisecond
+	checkPIDTries        = 5
+	checkPIDBaseWaitTime = 5 * time.Millisecond
 )
 
 // CheckPID checks the if socket info already has a PID and if not, tries to find it.
 // Depending on the OS, this might be a no-op.
 func CheckPID(socketInfo socket.Info, connInbound bool) (pid int, inbound bool, err error) {
-	for i := 1; i <= lookupTries; i++ {
+	for i := 1; i <= checkPIDTries; i++ {
 		// look for PID
 		pid = proc.GetPID(socketInfo)
 		if pid != socket.UndefinedProcessID {
@@ -31,10 +29,10 @@ func CheckPID(socketInfo socket.Info, connInbound bool) (pid int, inbound bool,
 		}
 
 		// every time, except for the last iteration
-		if i < lookupTries {
+		if i < checkPIDTries {
 			// we found no PID, we could have been too fast, give the kernel some time to think
-			// back off timer: with 3ms baseWaitTime: 3, 6, 9, 12, 15, 18, 21ms - 84ms in total
-			time.Sleep(time.Duration(i+1) * baseWaitTime)
+			// back off timer: with 5ms baseWaitTime: 5, 10, 15, 20, 25 - 75ms in total
+			time.Sleep(time.Duration(i) * checkPIDBaseWaitTime)
 		}
 	}