Put pcap parsing in utils class

pwnagotchi/utils.py

@@ -1,4 +1,5 @@
 from datetime import datetime
+from enum import Enum
 import logging
 import glob
 import os
@@ -83,6 +84,102 @@ def blink(times=1, delay=0.3):
         time.sleep(delay)
     led(True)
 
+class WifiInfo(Enum):
+    """
+    Fields you can extract from a pcap file
+    """
+    BSSID = 0
+    ESSID = 1
+    ENCRYPTION = 2
+    CHANNEL = 3
+    RSSI = 4
+
+class FieldNotFoundError(Exception):
+    pass
+
+
+def extract_from_pcap(path, fields):
+    """
+    Search in pcap-file for specified information
+
+    path: Path to pcap file
+    fields: Array of fields that should be extracted
+
+    If a field is not found, FieldNotFoundError is raised
+    """
+    results = dict()
+    for field in fields:
+        if not isinstance(field, WifiInfo):
+            raise TypeError("Invalid field")
+
+        subtypes = set()
+
+        if field == WifiInfo.BSSID:
+            from scapy.all import Dot11Beacon, Dot11ProbeResp, Dot11AssoReq, Dot11ReassoReq, Dot11, sniff
+            subtypes.add('beacon')
+            bpf_filter = " or ".join([f"wlan type mgt subtype {subtype}" for subtype in subtypes])
+            packets = sniff(offline=path, filter=bpf_filter)
+            try:
+                for packet in packets:
+                    if packet.haslayer(Dot11Beacon):
+                        if hasattr(packet[Dot11], 'addr3'):
+                            results[field] = packet[Dot11].addr3
+                            break
+                else: # magic
+                    raise FieldNotFoundError("Could not find field [BSSID]")
+            except Exception:
+                raise FieldNotFoundError("Could not find field [BSSID]")
+        elif field == WifiInfo.ESSID:
+            from scapy.all import Dot11Beacon, Dot11ReassoReq, Dot11AssoReq, Dot11, sniff, Dot11Elt
+            subtypes.add('beacon')
+            subtypes.add('assoc-req')
+            subtypes.add('reassoc-req')
+            bpf_filter = " or ".join([f"wlan type mgt subtype {subtype}" for subtype in subtypes])
+            packets = sniff(offline=path, filter=bpf_filter)
+            try:
+                for packet in packets:
+                    if packet.haslayer(Dot11Elt) and hasattr(packet[Dot11Elt], 'info'):
+                        results[field] = packet[Dot11Elt].info.decode('utf-8')
+                        break
+                else: # magic
+                    raise FieldNotFoundError("Could not find field [ESSID]")
+            except Exception:
+                raise FieldNotFoundError("Could not find field [ESSID]")
+        elif field == WifiInfo.ENCRYPTION:
+            from scapy.all import Dot11Beacon, sniff
+            subtypes.add('beacon')
+            bpf_filter = " or ".join([f"wlan type mgt subtype {subtype}" for subtype in subtypes])
+            packets = sniff(offline=path, filter=bpf_filter)
+            try:
+                for packet in packets:
+                    if packet.haslayer(Dot11Beacon) and hasattr(packet[Dot11Beacon], 'network_stats'):
+                        stats = packet[Dot11Beacon].network_stats()
+                        if 'crypto' in stats:
+                            results[field] = stats['crypto'] # set with encryption types
+                            break
+                else: # magic
+                    raise FieldNotFoundError("Could not find field [ENCRYPTION]")
+            except Exception:
+                raise FieldNotFoundError("Could not find field [ENCRYPTION]")
+        elif field == WifiInfo.CHANNEL:
+            from scapy.all import sniff, RadioTap
+            from pwnagotchi.mesh.wifi import freq_to_channel
+            packets = sniff(offline=path, count=1)
+            try:
+                results[field] = freq_to_channel(packets[0][RadioTap].ChannelFrequency)
+            except Exception:
+                raise FieldNotFoundError("Could not find field [CHANNEL]")
+        elif field == WifiInfo.RSSI:
+            from scapy.all import sniff, RadioTap
+            from pwnagotchi.mesh.wifi import freq_to_channel
+            packets = sniff(offline=path, count=1)
+            try:
+                results[field] = packets[0][RadioTap].dBm_AntSignal
+            except Exception:
+                raise FieldNotFoundError("Could not find field [RSSI]")
+
+    return results
+
 
 class StatusFile(object):
     def __init__(self, path, data_format='raw'):