refactor utils

backend/src/network_sniffer.py

@@ -5,6 +5,7 @@ import os
 import time
 from typing import List, Dict, Optional
 import asyncpg
+from src.utilities.interface_bridge_helpers import check_interface_exists, check_interface_up, get_bridge_ports_once
 from scapy.all import (
     Ether,
     ARP,
@@ -67,69 +68,6 @@ def start_async_loop(loop: asyncio.AbstractEventLoop) -> None:
 # Start the background asyncio loop thread (daemon so it doesn't block process exit).
 threading.Thread(target=start_async_loop, args=(async_loop,), daemon=True).start()
 
-# -------------------------
-# Interface / bridge helpers
-# -------------------------
-def check_interface_exists(iface: str) -> bool:
-    """
-    Check for the presence of a network interface by testing sysfs.
-    Returns True if /sys/class/net/<iface> exists.
-    """
-    return os.path.isdir(f"/sys/class/net/{iface}")
-
-
-def check_interface_up(iface: str) -> bool:
-    """
-    Check whether the given interface is administratively/operationally up
-    by reading /sys/class/net/<iface>/operstate.
-    Returns False if the path does not exist.
-    """
-    try:
-        with open(f"/sys/class/net/{iface}/operstate", "r") as f:
-            return f.read().strip() == "up"
-    except FileNotFoundError:
-        return False
-
-
-def _read_bridge_ports_from_sysfs(bridge: str) -> List[str]:
-    """
-    Read bridge member interfaces from sysfs. Internal helper that always reads.
-    """
-    base = f"/sys/class/net/{bridge}/brif/"
-    if not os.path.isdir(base):
-        return []
-
-    try:
-        ports = [p for p in os.listdir(base) if check_interface_exists(p)]
-    except Exception:
-        logger.exception("Error reading bridge ports for %s", bridge)
-        ports = []
-    return ports
-
-
-def get_bridge_ports_once(bridge: str) -> List[str]:
-    """
-    Convenience: read bridge ports (no caching here) used when preparing the fixed snapshot.
-    """
-    return _read_bridge_ports_from_sysfs(bridge)
-
-
-def determine_direction(pkt_iface: str, bridge: str):
-    """
-    Determine ingress/egress using the fixed snapshot of bridge ports
-    taken when the sniffer started. This avoids reading sysfs for every
-    packet and prevents noisy logs when bridge ports are static.
-
-    If snapshot is missing (defensive), fall back to a direct sysfs read.
-    """
-    ports = fixed_bridge_ports.get(bridge)
-    if ports is None:
-        # Defensive fallback (should not happen if start_afpacket_sniffer was used)
-        ports = _read_bridge_ports_from_sysfs(bridge)
-    ingress = pkt_iface
-    egress = [p for p in ports if p != pkt_iface]
-    return ingress, egress
-
 
 # -------------------------------------------------------------------
 # Database insertion

backend/src/utilities/interface_bridge_helpers.py

@@ -0,0 +1,54 @@
+from typing import List, Dict, Optional
+import logging
+import os
+
+# ---- Logging ----------------------------------------------------------
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger("af_packet_sniffer")
+
+# -------------------------
+# Interface / bridge helpers
+# -------------------------
+
+def check_interface_exists(iface: str) -> bool:
+    """
+    Check for the presence of a network interface by testing sysfs.
+    Returns True if /sys/class/net/<iface> exists.
+    """
+    return os.path.isdir(f"/sys/class/net/{iface}")
+
+
+def check_interface_up(iface: str) -> bool:
+    """
+    Check whether the given interface is administratively/operationally up
+    by reading /sys/class/net/<iface>/operstate.
+    Returns False if the path does not exist.
+    """
+    try:
+        with open(f"/sys/class/net/{iface}/operstate", "r") as f:
+            return f.read().strip() == "up"
+    except FileNotFoundError:
+        return False
+
+
+def _read_bridge_ports_from_sysfs(bridge: str) -> List[str]:
+    """
+    Read bridge member interfaces from sysfs. Internal helper that always reads.
+    """
+    base = f"/sys/class/net/{bridge}/brif/"
+    if not os.path.isdir(base):
+        return []
+
+    try:
+        ports = [p for p in os.listdir(base) if check_interface_exists(p)]
+    except Exception:
+        logger.exception("Error reading bridge ports for %s", bridge)
+        ports = []
+    return ports
+
+
+def get_bridge_ports_once(bridge: str) -> List[str]:
+    """
+    Convenience: read bridge ports (no caching here) used when preparing the fixed snapshot.
+    """
+    return _read_bridge_ports_from_sysfs(bridge)