From 29986d507305606e4dedc7c559b9eeb7deb666b8 Mon Sep 17 00:00:00 2001
From: malmert <marcus.almert@gmail.com>
Date: Sat, 7 Mar 2026 16:48:37 +0100
Subject: [PATCH] tc test 5

---
 backend/src/utilities/ebpf_bridge_events.py | 93 ++++++++-------------
 1 file changed, 37 insertions(+), 56 deletions(-)

diff --git a/backend/src/utilities/ebpf_bridge_events.py b/backend/src/utilities/ebpf_bridge_events.py
index 938ee56..5eed1d5 100644
--- a/backend/src/utilities/ebpf_bridge_events.py
+++ b/backend/src/utilities/ebpf_bridge_events.py
@@ -10,7 +10,6 @@ import hashlib
 import ipaddress
 import json
 import signal
-import shutil
 import socket
 import subprocess
 import sys
@@ -44,7 +43,6 @@ EVENT_EGRESS = 2
 EVENT_DROP = 3
 INGRESS_PARENT = "ffff:fff2"
 EGRESS_PARENT = "ffff:fff3"
-MARK_FILTER_PREF = 10
 INGRESS_FILTER_HANDLE = ":20"
 EGRESS_FILTER_HANDLE = ":30"
 
@@ -114,6 +112,41 @@ struct event_t {
 BPF_PERF_OUTPUT(ingress_events);
 BPF_PERF_OUTPUT(meta_events);
 
+struct counter_state {
+  struct bpf_spin_lock lock;
+  __u32 value;
+};
+
+struct {
+  __uint(type, BPF_MAP_TYPE_ARRAY);
+  __uint(max_entries, 1);
+  __type(key, __u32);
+  __type(value, struct counter_state);
+} packet_counter SEC(".maps");
+
+static __always_inline __u32 ensure_packet_mark(struct __sk_buff *skb) {
+  __u32 key = 0;
+  __u32 next = skb->mark;
+  struct counter_state *state;
+
+  if (next) {
+    return next;
+  }
+
+  state = bpf_map_lookup_elem(&packet_counter, &key);
+  if (!state) {
+    return 0;
+  }
+
+  bpf_spin_lock(&state->lock);
+  state->value += 1;
+  next = state->value;
+  bpf_spin_unlock(&state->lock);
+
+  skb->mark = next;
+  return next;
+}
+
 static __always_inline int parse_l3_l4_direct(struct event_t *event, void *data, void *data_end) {
   struct ethhdr *eth = data;
   __be16 eth_proto;
@@ -323,7 +356,7 @@ int handle_ingress(struct __sk_buff *skb) {
   event.event_type = EVENT_INGRESS;
   event.ifindex = skb->ifindex;
   event.length = skb->len;
-  event.skb_mark = skb->mark;
+  event.skb_mark = ensure_packet_mark(skb);
 
   if (!event.skb_mark) {
     return TC_ACT_OK;
@@ -419,34 +452,6 @@ def _run_checked(cmd: list[str]) -> None:
     subprocess.run(cmd, check=True, capture_output=True, text=True)
 
 
-def _multiarch_include_flag() -> list[str]:
-    if shutil.which("gcc") is None:
-        return []
-    try:
-        triple = subprocess.run(["gcc", "-dumpmachine"], check=True, capture_output=True, text=True).stdout.strip()
-    except Exception:
-        return []
-    include_dir = Path("/usr/include") / triple
-    return [f"-I{include_dir}"] if include_dir.is_dir() else []
-
-
-def _repo_root() -> Path:
-    return Path(__file__).resolve().parents[3]
-
-
-def _ensure_mark_object(build_dir: str) -> Path:
-    build_path = Path(build_dir)
-    build_path.mkdir(parents=True, exist_ok=True)
-    src = _repo_root() / "tools" / "ebpf" / "mark_packet_id.c"
-    obj = build_path / "mark_packet_id.o"
-    if obj.exists() and obj.stat().st_mtime >= src.stat().st_mtime:
-        return obj
-
-    cmd = ["clang", "-O2", "-g", "-target", "bpf", *_multiarch_include_flag(), "-c", str(src), "-o", str(obj)]
-    _run_checked(cmd)
-    return obj
-
-
 def _ifname_from_index(ifindex: int) -> str | None:
     if ifindex <= 0:
         return None
@@ -575,32 +580,9 @@ def _ensure_clean_clsact(iface: str) -> None:
     _run_checked(["tc", "qdisc", "add", "dev", iface, "clsact"])
 
 
-def _attach_mark_filter(iface: str, obj_path: Path) -> None:
-    _run_checked(
-        [
-            "tc",
-            "filter",
-            "replace",
-            "dev",
-            iface,
-            "ingress",
-            "pref",
-            str(MARK_FILTER_PREF),
-            "protocol",
-            "all",
-            "bpf",
-            "direct-action",
-            "obj",
-            str(obj_path),
-            "sec",
-            "classifier",
-        ]
-    )
-
-
 def _attach_tc_programs(bpf: BPF, ifaces: list[str], build_dir: str) -> tuple[str, str]:
     global IPR
-    obj_path = _ensure_mark_object(build_dir)
+    del build_dir
     ingress_fn = bpf.load_func("handle_ingress", BPF.SCHED_CLS)
     egress_fn = bpf.load_func("handle_egress", BPF.SCHED_CLS)
 
@@ -612,7 +594,6 @@ def _attach_tc_programs(bpf: BPF, ifaces: list[str], build_dir: str) -> tuple[st
                 raise RuntimeError(f"Interface not found: {iface}")
             ifindex = matches[0]
             _ensure_clean_clsact(iface)
-            _attach_mark_filter(iface, obj_path)
             ipr.tc(
                 "add-filter",
                 "bpf",