move examples to examples folder

examples/anomaly-detection/lib/probe.py

@@ -0,0 +1,117 @@
+"""
+PythonBPF eBPF Probe for Syscall Histogram Collection
+"""
+
+from vmlinux import struct_trace_event_raw_sys_enter
+from pythonbpf import bpf, map, section, bpfglobal, BPF
+from pythonbpf.helper import pid
+from pythonbpf.maps import HashMap
+from ctypes import c_int64
+from lib import MAX_SYSCALLS, comm_for_pid
+
+
+@bpf
+@map
+def histogram() -> HashMap:
+    return HashMap(key=c_int64, value=c_int64, max_entries=1024)
+
+
+@bpf
+@map
+def target_pid_map() -> HashMap:
+    return HashMap(key=c_int64, value=c_int64, max_entries=1)
+
+
+@bpf
+@section("tracepoint/raw_syscalls/sys_enter")
+def trace_syscall(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
+    syscall_id = ctx.id
+    current_pid = pid()
+    target = target_pid_map.lookup(0)
+    if target:
+        if current_pid != target:
+            return 0  # type: ignore
+    if syscall_id < 0 or syscall_id >= 548:
+        return 0  # type: ignore
+    count = histogram.lookup(syscall_id)
+    if count:
+        histogram.update(syscall_id, count + 1)
+    else:
+        histogram.update(syscall_id, 1)
+    return 0  # type: ignore
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+ebpf_prog = BPF()
+
+
+class Probe:
+    """
+    Syscall histogram probe for a target process.
+
+    Usage:
+        probe = Probe(target_pid=1234)
+        probe.start()
+        histogram = probe.get_histogram()
+    """
+
+    def __init__(self, target_pid: int, max_syscalls: int = MAX_SYSCALLS):
+        self.target_pid = target_pid
+        self.max_syscalls = max_syscalls
+        self.comm = comm_for_pid(target_pid)
+
+        if self.comm is None:
+            raise ValueError(f"Cannot find process with PID {target_pid}")
+
+        self._bpf = None
+        self._histogram_map = None
+        self._target_map = None
+
+    def start(self):
+        """Compile, load, and attach the BPF probe."""
+        # Compile and load
+        self._bpf = ebpf_prog
+        self._bpf.load()
+        self._bpf.attach_all()
+
+        # Get map references
+        self._histogram_map = self._bpf["histogram"]
+        self._target_map = self._bpf["target_pid_map"]
+
+        # Set target PID in the map
+        self._target_map.update(0, self.target_pid)
+
+        return self
+
+    def get_histogram(self) -> list:
+        """Read current histogram values as a list."""
+        if self._histogram_map is None:
+            raise RuntimeError("Probe not started.  Call start() first.")
+
+        result = [0] * self.max_syscalls
+
+        for syscall_id in range(self.max_syscalls):
+            try:
+                count = self._histogram_map.lookup(syscall_id)
+                if count is not None:
+                    result[syscall_id] = int(count)
+            except Exception:
+                pass
+
+        return result
+
+    def __getitem__(self, syscall_id: int) -> int:
+        """Allow indexing: probe[syscall_id]"""
+        if self._histogram_map is None:
+            raise RuntimeError("Probe not started")
+
+        try:
+            count = self._histogram_map.lookup(syscall_id)
+            return int(count) if count is not None else 0
+        except Exception:
+            return 0