Added PortRange class that generates ports to scan

2 files changed, 74 insertions, 7 deletions

diff --git a/src/main/java/com/it_jaros/networkScanner/PortRange.java b/src/main/java/com/it_jaros/networkScanner/PortRange.java
new file mode 100644
index 0000000..cdef5cf
--- /dev/null
+++ b/src/main/java/com/it_jaros/networkScanner/PortRange.java
@@ -0,0 +1,67 @@
+package com.it_jaros.networkScanner;
+
+import java.util.BitSet;
+import java.util.NoSuchElementException;
+
+public class PortRange {
+
+    private static final int MIN_PORT = 1;
+    private static final int MAX_PORT = 65535;
+    private final BitSet portsRange = new BitSet(MAX_PORT);
+    private final BitSet available = new BitSet(MAX_PORT);
+
+    private int cursor;
+    private int done = 0;
+    private int total = 0;
+
+    public PortRange(String ports) {
+        if (ports == null || "".equals(ports)) {
+            // keep defaults
+            portsRange.set(1, 1024 + 1);
+            return;
+        }
+
+        String[] splitComma = ports.split(",");
+        for (String commaValue: splitComma) {
+            if (commaValue.contains("-")) {
+                String[] splitRange = commaValue.split("-");
+                if (splitRange.length > 2) {
+                    throw new IllegalArgumentException(String.format("Argument contains too many '-'' %s", commaValue));
+                }
+                
+                int start = Integer.parseInt(splitRange[0]);
+                int end = Integer.parseInt(splitRange[1]);
+                portsRange.set(start, end + 1);
+            } else {
+                portsRange.set(Integer.parseInt(commaValue));
+            }
+        }
+        
+        available.or(portsRange);
+        cursor = available.nextSetBit(MIN_PORT);
+    }
+
+    public synchronized int next() {
+        int p = available.nextSetBit(cursor);
+        if (p > 0) {
+            available.clear(p);
+            cursor = p + 1;
+            done++;
+            return p;
+        }
+
+        throw new NoSuchElementException("Reached end of port range");
+    }
+
+    public synchronized boolean hasNext() {
+        return available.nextSetBit(cursor) > 0;
+    }
+
+    public int getTotal() {
+        return portsRange.cardinality();
+    }
+
+    public int getDone() {
+        return done;
+    }
+}
diff --git a/src/main/java/com/it_jaros/networkScanner/Scanner.java b/src/main/java/com/it_jaros/networkScanner/Scanner.java
index fae1890..10028aa 100644
--- a/src/main/java/com/it_jaros/networkScanner/Scanner.java
+++ b/src/main/java/com/it_jaros/networkScanner/Scanner.java
@@ -34,18 +34,18 @@ public class Scanner {
     }
 
     public List<ScanResult> scanPorts(ScanOptions target) {
-        return scanPorts(target.targets(), target.delayInMillis());
+        return scanPorts(target.targets(), target.delayInMillis(), new PortRange(target.ports()));
     }
 
-    public List<ScanResult> scanPorts(List<String> targets, int delayInMillis) {
+    public List<ScanResult> scanPorts(List<String> targets, int delayInMillis, PortRange portsRange) {
         List<ScanResult> results = new ArrayList<>();
         long delayInNanos = TimeUnit.MILLISECONDS.toNanos(Math.max(0, delayInMillis));
         try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();) {
             List<Progress> hosts = new ArrayList<>();
             for (String target : targets) {
-                Progress progress = new Progress(target, 65535, new AtomicInteger(), new AtomicInteger());
+                Progress progress = new Progress(target, portsRange.getTotal(), new AtomicInteger(), new AtomicInteger());
                 hosts.add(progress);
-                results.add(scanTargetAsync(target, delayInNanos, executor, progress));
+                results.add(scanTargetAsync(target, portsRange, delayInNanos, executor, progress));
             }
             progressBar.start(hosts);
         }
@@ -55,11 +55,11 @@ public class Scanner {
         return results;
     }
 
-    private ScanResult scanTargetAsync(String target, long delayInNanos, ExecutorService executor, Progress p) {
+    private ScanResult scanTargetAsync(String target, PortRange portRange, long delayInNanos, ExecutorService executor, Progress p) {
         AtomicLong nextStartNanos = new AtomicLong(System.nanoTime());
         Queue<Integer> openPorts = new ConcurrentLinkedQueue<>();
-        for (int port = 1; port < 65536; port++) {
-            final int currentPort = port;
+        while (portRange.hasNext()) {
+            final int currentPort = portRange.next();
             executor.submit(() -> {
                 try {
                     scanPortsAsync(target, delayInNanos, nextStartNanos, openPorts, currentPort);