tc full packet test

backend/src/utilities/packet_mark.py

@@ -0,0 +1,46 @@
+"""Helpers for the shared skb mark layout used for packet correlation and verdict hints."""
+
+from __future__ import annotations
+
+from typing import Optional
+
+
+PACKET_ID_MASK = 0x0FFFFFFF
+VERDICT_MASK = 0xF0000000
+VERDICT_FLAG_DROP = 0x10000000
+VERDICT_FLAG_REJECT = 0x20000000
+
+
+def normalize_skb_mark(value: object) -> Optional[int]:
+    """Return a positive integer skb mark or `None` when the value is empty."""
+    if value in (None, "", 0, "0"):
+        return None
+    try:
+        mark = int(value)
+    except (TypeError, ValueError):
+        return None
+    if mark < 0:
+        mark &= 0xFFFFFFFF
+    return mark or None
+
+
+def packet_id_from_mark(value: object) -> Optional[str]:
+    """Extract the packet correlation identifier from the shared skb mark layout."""
+    mark = normalize_skb_mark(value)
+    if mark is None:
+        return None
+    packet_id = mark & PACKET_ID_MASK
+    return str(packet_id) if packet_id else None
+
+
+def verdict_from_mark(value: object) -> Optional[str]:
+    """Return a verdict hint encoded into the upper mark bits, if any."""
+    mark = normalize_skb_mark(value)
+    if mark is None:
+        return None
+    verdict_bits = mark & VERDICT_MASK
+    if verdict_bits & VERDICT_FLAG_REJECT:
+        return "reject"
+    if verdict_bits & VERDICT_FLAG_DROP:
+        return "drop"
+    return None