100 lines
3.3 KiB
Python
100 lines
3.3 KiB
Python
# SPDX-License-Identifier: GPL-3.0-or-later
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"""Runs optional eBPF event sources on threads and routes them through rules."""
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from __future__ import annotations
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import threading
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from collections.abc import Callable
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from ..alert import Alert
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from ..config import Config
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from . import bcc_source, bcc_syscall_source
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from .exec_event import ExecEvent
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from .rules import ExecRuleEngine
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from .syscall_event import SyscallEvent
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from .syscall_rules import SyscallRuleEngine
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class ExecMonitor:
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"""Owns the event source + rule engine; emits Alerts via ``on_alert``.
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``start()`` is best-effort: it returns a (started, reason) pair and never
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raises, so the daemon can log the reason and carry on with polling.
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"""
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def __init__(self, cfg: Config, on_alert: Callable[[Alert], None]) -> None:
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self.cfg = cfg
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self._on_alert = on_alert
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self.engine = ExecRuleEngine.load(cfg.exec_rules_file)
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self._source = bcc_source.BccExecSource(self._on_event)
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self._thread: threading.Thread | None = None
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self._stop = threading.Event()
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def start(self) -> tuple[bool, str]:
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ok, reason = bcc_source.available()
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if not ok:
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return False, reason
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try:
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self._source.start()
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except Exception as exc: # compilation/attach/permission failure
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return False, f"probe load failed: {exc!r}"
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self._thread = threading.Thread(target=self._run, daemon=True)
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self._thread.start()
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return True, "ok"
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def _run(self) -> None:
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while not self._stop.is_set():
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try:
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self._source.poll(timeout_ms=200)
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except Exception:
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break
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def _on_event(self, ev: ExecEvent) -> None:
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for alert in self.engine.match(ev):
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self._on_alert(alert)
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def stop(self) -> None:
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self._stop.set()
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self._source.stop()
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class SyscallMonitor:
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"""Owns the syscall event source + rule engine; emits Alerts via callback."""
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def __init__(self, cfg: Config, on_alert: Callable[[Alert], None]) -> None:
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self.cfg = cfg
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self._on_alert = on_alert
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self.engine = SyscallRuleEngine()
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self._source = bcc_syscall_source.BccSyscallSource(self._on_event)
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self._thread: threading.Thread | None = None
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self._stop = threading.Event()
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def start(self) -> tuple[bool, str]:
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ok, reason = bcc_syscall_source.available()
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if not ok:
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return False, reason
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try:
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self._source.start()
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except Exception as exc:
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return False, f"probe load failed: {exc!r}"
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self._thread = threading.Thread(target=self._run, daemon=True)
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self._thread.start()
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reason = "ok"
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if self._source.attach_errors:
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reason = "ok (some probes unavailable: " + "; ".join(
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self._source.attach_errors[:4]) + ")"
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return True, reason
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def _run(self) -> None:
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while not self._stop.is_set():
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try:
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self._source.poll(timeout_ms=200)
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except Exception:
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break
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def _on_event(self, ev: SyscallEvent) -> None:
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for alert in self.engine.match(ev):
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self._on_alert(alert)
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def stop(self) -> None:
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self._stop.set()
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self._source.stop()
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