mirror of
https://github.com/andrey271192/kaskad_web_vpn.git
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d3a69e6ec5
README turnkey focus; remove BOT fields and yaskad label; neutral iptables comments; default SERVICE_UNITS without bot units. Co-authored-by: Cursor <cursoragent@cursor.com>
463 lines
14 KiB
Python
463 lines
14 KiB
Python
"""Хранение правил NAT и синхронизация с iptables.
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Режимы (KASKAD_IPTABLES_MODE):
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- compat — DNAT в PREROUTING, INPUT/FORWARD с комментарием kaskad:PORT:proto, MASQUERADE.
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- chain — отдельная цепочка nat/KASKAD_WEB (альтернатива).
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"""
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from __future__ import annotations
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import ipaddress
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import json
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import logging
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import os
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import re
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import shutil
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import subprocess
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import uuid
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from pathlib import Path
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from typing import Any
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log = logging.getLogger(__name__)
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RULES_PATH = Path(os.environ.get("KASKAD_RULES_PATH", "/var/lib/kaskad/rules.json"))
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CHAIN = os.environ.get("KASKAD_NAT_CHAIN", "KASKAD_WEB").strip() or "KASKAD_WEB"
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IPTABLES_MODE = os.environ.get("KASKAD_IPTABLES_MODE", "compat").strip().lower()
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_PROTO_OK = frozenset({"tcp", "udp"})
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def _iptables_bin() -> str | None:
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for name in ("iptables", "iptables-nft", "iptables-legacy"):
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p = shutil.which(name)
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if p:
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return p
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return None
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def ensure_state_dir() -> None:
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RULES_PATH.parent.mkdir(parents=True, exist_ok=True)
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def load_rules() -> list[dict[str, Any]]:
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ensure_state_dir()
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if not RULES_PATH.is_file():
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return []
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try:
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raw = json.loads(RULES_PATH.read_text(encoding="utf-8"))
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except (json.JSONDecodeError, OSError) as e:
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log.warning("rules read failed: %s", e)
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return []
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rules = raw.get("rules") if isinstance(raw, dict) else raw
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if not isinstance(rules, list):
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return []
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out: list[dict[str, Any]] = []
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for r in rules:
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if isinstance(r, dict) and r.get("id"):
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out.append(r)
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return out
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def save_rules(rules: list[dict[str, Any]]) -> None:
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ensure_state_dir()
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tmp = RULES_PATH.with_suffix(".tmp")
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tmp.write_text(json.dumps({"rules": rules}, ensure_ascii=False, indent=2), encoding="utf-8")
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tmp.replace(RULES_PATH)
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def _validate_rule(r: dict[str, Any]) -> None:
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proto = str(r.get("proto", "")).lower().strip()
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if proto not in _PROTO_OK:
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raise ValueError("proto должен быть tcp или udp")
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ipaddress.IPv4Address(str(r.get("target", "")))
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for key in ("in_port", "out_port"):
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p = int(r[key])
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if not (1 <= p <= 65535):
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raise ValueError(f"порт {key} вне диапазона")
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user = str(r.get("user", "")).strip()
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if not user or len(user) > 64:
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raise ValueError("USER: 1–64 символа")
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if any(ord(c) < 32 for c in user):
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raise ValueError("USER: недопустимые символы")
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note = str(r.get("note", ""))
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where = str(r.get("where", ""))
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if len(note) > 256 or len(where) > 256:
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raise ValueError("заметка / где — не длиннее 256 символов")
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def normalize_rule(body: dict[str, Any], rid: str | None = None) -> dict[str, Any]:
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try:
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in_p = int(body.get("in_port"))
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out_p = int(body.get("out_port"))
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except (TypeError, ValueError):
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raise ValueError("in_port и out_port должны быть целыми числами") from None
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r = {
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"id": rid or uuid.uuid4().hex[:16],
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"user": str(body.get("user", "")).strip(),
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"proto": str(body.get("proto", "udp")).lower().strip(),
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"in_port": in_p,
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"target": str(body.get("target", "")).strip(),
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"out_port": out_p,
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"note": str(body.get("note", "")).strip(),
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"where": str(body.get("where", "")).strip(),
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}
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_validate_rule(r)
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return r
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def _run_iptables(args: list[str]) -> tuple[int, str]:
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exe = _iptables_bin()
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if not exe:
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return 127, "iptables не найден в PATH"
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try:
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p = subprocess.run(
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[exe, *args],
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capture_output=True,
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text=True,
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timeout=30,
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)
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err = (p.stderr or p.stdout or "").strip()
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return p.returncode, err
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except Exception as e:
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return 1, str(e)
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def detect_out_interface() -> str | None:
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env = os.environ.get("KASKAD_OUT_IFACE", "").strip()
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if env:
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return env
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try:
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p = subprocess.run(
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["ip", "-4", "route", "get", "8.8.8.8"],
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capture_output=True,
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text=True,
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timeout=5,
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)
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if p.returncode != 0:
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return None
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m = re.search(r"\bdev\s+(\S+)", p.stdout or "")
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return m.group(1) if m else None
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except Exception:
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return None
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def _kaskad_comment(in_port: int, proto: str) -> str:
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return f"kaskad:{int(in_port)}:{proto}"
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def _iptables_delete_line(table: str | None, full_line: str) -> tuple[int, str]:
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"""Строка из `iptables -S`: `-A`/`-I CHAIN ...` → удаление через `-D`."""
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parts = full_line.strip().split()
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if len(parts) < 3:
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return 1, "bad iptables line"
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op = parts[0]
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if op not in ("-A", "-I"):
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return 1, f"unsupported {op}"
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parts[0] = "-D"
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if op == "-I" and len(parts) > 3 and parts[2].isdigit():
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parts.pop(2)
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args = parts
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if table:
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args = ["-t", table] + args
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return _run_iptables(args)
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def _flush_matching_rules(table: str | None, chain: str, predicate) -> None:
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for _ in range(64):
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rc, out = _run_iptables(["-t", table, "-S", chain] if table else ["-S", chain])
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if rc != 0:
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break
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prefix = f"-A {chain} "
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victim = None
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for line in (out or "").splitlines():
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line = line.strip()
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if not line.startswith(prefix):
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continue
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rest = line[len(prefix) :]
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if predicate(rest):
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victim = line
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break
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if not victim:
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break
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rc2, err = _iptables_delete_line(table, victim)
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if rc2 != 0:
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log.debug("iptables delete fail: %s", err)
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break
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def compat_remove_rule(proto: str, in_port: int) -> None:
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"""Удаляет связанные DNAT и правила filter по порту/протоколу."""
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cm = _kaskad_comment(in_port, proto)
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def pred_nat(rest: str) -> bool:
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return (
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f"-p {proto}" in rest
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and f"--dport {in_port}" in rest
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and "DNAT" in rest
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and "--to-destination" in rest
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)
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_flush_matching_rules("nat", "PREROUTING", pred_nat)
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def pred_filter(rest: str) -> bool:
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return cm in rest
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_flush_matching_rules(None, "INPUT", pred_filter)
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_flush_matching_rules(None, "FORWARD", pred_filter)
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def compat_apply_rule(r: dict[str, Any], iface: str) -> tuple[bool, str]:
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proto = str(r["proto"])
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in_port = int(r["in_port"])
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out_port = int(r["out_port"])
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target = str(r["target"])
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cm = _kaskad_comment(in_port, proto)
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compat_remove_rule(proto, in_port)
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rc, err = _run_iptables(
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[
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"-I",
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"INPUT",
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"1",
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"-p",
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proto,
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"--dport",
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str(in_port),
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"-m",
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"comment",
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"--comment",
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cm,
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"-j",
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"ACCEPT",
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]
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)
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if rc != 0:
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return False, f"INPUT: {err}"
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rc, err = _run_iptables(
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[
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"-t",
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"nat",
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"-A",
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"PREROUTING",
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"-p",
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proto,
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"--dport",
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str(in_port),
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"-j",
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"DNAT",
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"--to-destination",
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f"{target}:{out_port}",
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]
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)
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if rc != 0:
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return False, f"PREROUTING DNAT: {err}"
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rc, err = _run_iptables(
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[
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"-I",
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"FORWARD",
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"1",
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"-p",
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proto,
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"-d",
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target,
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"--dport",
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str(out_port),
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"-m",
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"state",
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"--state",
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"NEW,ESTABLISHED,RELATED",
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"-m",
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"comment",
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"--comment",
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cm,
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"-j",
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"ACCEPT",
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]
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)
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if rc != 0:
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return False, f"FORWARD→dst: {err}"
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rc, err = _run_iptables(
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[
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"-I",
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"FORWARD",
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"1",
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"-p",
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proto,
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"-s",
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target,
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"--sport",
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str(out_port),
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"-m",
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"state",
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"--state",
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"ESTABLISHED,RELATED",
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"-m",
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"comment",
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"--comment",
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cm,
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"-j",
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"ACCEPT",
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]
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)
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if rc != 0:
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return False, f"FORWARD←src: {err}"
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return True, ""
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def _ensure_masquerade(iface: str) -> tuple[bool, str]:
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rc, _ = _run_iptables(["-t", "nat", "-C", "POSTROUTING", "-o", iface, "-j", "MASQUERADE"])
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if rc == 0:
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return True, ""
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rc2, err = _run_iptables(["-t", "nat", "-A", "POSTROUTING", "-o", iface, "-j", "MASQUERADE"])
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if rc2 != 0:
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return False, err
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return True, ""
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def _save_persistent() -> None:
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if shutil.which("netfilter-persistent"):
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subprocess.run(
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["netfilter-persistent", "save"],
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capture_output=True,
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timeout=60,
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)
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elif shutil.which("iptables-save") and Path("/etc/init.d/iptables").is_file():
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subprocess.run(["service", "iptables", "save"], capture_output=True, timeout=60)
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def sync_iptables_compat(rules: list[dict[str, Any]]) -> tuple[bool, str]:
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iface = detect_out_interface()
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if not iface:
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return False, "не удалось определить исходящий интерфейс (задайте KASKAD_OUT_IFACE)"
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old_disk = load_rules()
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for r in old_disk:
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compat_remove_rule(str(r["proto"]), int(r["in_port"]))
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for r in rules:
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ok, msg = compat_apply_rule(r, iface)
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if not ok:
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return False, msg
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ok_m, msg_m = _ensure_masquerade(iface)
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if not ok_m:
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return False, f"MASQUERADE: {msg_m}"
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try:
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_save_persistent()
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except Exception as e:
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log.debug("persistent save: %s", e)
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return True, ""
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def sync_iptables_chain(rules: list[dict[str, Any]]) -> tuple[bool, str]:
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exe = _iptables_bin()
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if not exe:
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return False, "iptables недоступен (нет бинарника). Для Docker нужен образ с iptables и права NET_ADMIN."
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rc, err = _run_iptables(["-t", "nat", "-N", CHAIN])
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if rc != 0:
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el = err.lower()
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if "exists" not in el:
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return False, f"не удалось создать цепочку {CHAIN}: {err}"
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rc, _out = _run_iptables(["-t", "nat", "-C", "PREROUTING", "-j", CHAIN])
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if rc != 0:
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rc2, err2 = _run_iptables(["-t", "nat", "-I", "PREROUTING", "1", "-j", CHAIN])
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if rc2 != 0:
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return False, f"не удалось привязать PREROUTING → {CHAIN}: {err2}"
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rc, ferr = _run_iptables(["-t", "nat", "-F", CHAIN])
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if rc != 0:
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return False, f"flush {CHAIN}: {ferr}"
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for r in rules:
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rid = str(r["id"])
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proto = str(r["proto"])
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comment = f"kaskad-{rid}"
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cmd = [
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"-t",
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"nat",
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"-A",
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CHAIN,
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"-p",
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proto,
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"--dport",
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str(int(r["in_port"])),
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"-j",
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"DNAT",
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"--to-destination",
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f'{r["target"]}:{int(r["out_port"])}',
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"-m",
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"comment",
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"--comment",
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comment,
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]
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rc, emsg = _run_iptables(cmd)
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if rc != 0:
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return False, f"правило {rid}: {emsg}"
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return True, ""
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def sync_iptables(rules: list[dict[str, Any]]) -> tuple[bool, str]:
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if IPTABLES_MODE == "chain":
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return sync_iptables_chain(rules)
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return sync_iptables_compat(rules)
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def iptables_chain_dump() -> str:
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exe = _iptables_bin()
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if not exe:
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return "(iptables недоступен)"
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try:
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if IPTABLES_MODE == "chain":
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p = subprocess.run(
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[exe, "-t", "nat", "-S", CHAIN],
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capture_output=True,
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text=True,
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timeout=15,
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)
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out = (p.stdout or "").strip()
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err = (p.stderr or "").strip()
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if p.returncode != 0:
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return err or out or f"(цепочка {CHAIN}: не создана или недоступна)"
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return out if out else f"(цепочка {CHAIN} пуста)"
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chunks: list[str] = []
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for label, args in [
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("# nat PREROUTING (DNAT)", ["-t", "nat", "-S", "PREROUTING"]),
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("# filter INPUT (kaskad)", ["-S", "INPUT"]),
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("# filter FORWARD (kaskad)", ["-S", "FORWARD"]),
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("# nat POSTROUTING (MASQUERADE)", ["-t", "nat", "-S", "POSTROUTING"]),
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]:
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p = subprocess.run([exe, *args], capture_output=True, text=True, timeout=15)
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body = (p.stdout or "").strip()
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lines = [
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ln
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for ln in body.splitlines()
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if "kaskad:" in ln or ("DNAT" in ln and "PREROUTING" in args[2])
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or ("MASQUERADE" in ln and "POSTROUTING" in args[2])
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]
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chunks.append(label)
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chunks.append("\n".join(lines) if lines else "(нет совпадений)")
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return "\n".join(chunks)
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except Exception as e:
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return f"(ошибка: {e})"
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def startup_resync() -> None:
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try:
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rules = load_rules()
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ok, msg = sync_iptables(rules)
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if ok:
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log.info("iptables синхронизированы (%s), правил: %s", IPTABLES_MODE, len(rules))
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else:
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log.warning("iptables не синхронизированы: %s", msg)
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except Exception as e:
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log.warning("startup_resync: %s", e)
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