83 lines
2.5 KiB
Python
83 lines
2.5 KiB
Python
"""路由、白名单和转发器共用的网络基础函数。"""
|
|
|
|
import functools
|
|
import ipaddress
|
|
import socket
|
|
import threading
|
|
import time
|
|
|
|
|
|
def ttl_cache(seconds: int, maxsize: int = 16384):
|
|
"""带 TTL 的小型线程安全缓存，并保留 ``cache_clear`` 兼容接口。"""
|
|
def decorator(function):
|
|
store = {}
|
|
lock = threading.Lock()
|
|
|
|
@functools.wraps(function)
|
|
def wrapper(*args, **kwargs):
|
|
key = (args, tuple(sorted(kwargs.items())))
|
|
now = time.time()
|
|
with lock:
|
|
hit = store.get(key)
|
|
if hit and now - hit[0] < seconds:
|
|
return hit[1]
|
|
value = function(*args, **kwargs)
|
|
with lock:
|
|
store[key] = (now, value)
|
|
if len(store) > maxsize:
|
|
cutoff = now - seconds
|
|
for cached_key, (timestamp, _) in list(store.items()):
|
|
if timestamp < cutoff:
|
|
del store[cached_key]
|
|
if len(store) > maxsize:
|
|
store.clear()
|
|
return value
|
|
|
|
def cache_clear():
|
|
with lock:
|
|
store.clear()
|
|
|
|
wrapper.cache_clear = cache_clear
|
|
return wrapper
|
|
return decorator
|
|
|
|
|
|
def is_private_ipv4_int(value: int) -> bool:
|
|
"""整数形式 IPv4 是否属于常见私网、回环或链路本地段。"""
|
|
return (
|
|
(value & 0xFF000000) == 0x0A000000
|
|
or (value & 0xFFF00000) == 0xAC100000
|
|
or (value & 0xFFFF0000) == 0xC0A80000
|
|
or (value & 0xFF000000) == 0x7F000000
|
|
or (value & 0xFFFF0000) == 0xA9FE0000
|
|
)
|
|
|
|
|
|
def resolve_host_ips(host: str):
|
|
"""解析主机名的 IPv4/IPv6 集合；字面量 IP 返回自身，失败返回空集合。"""
|
|
try:
|
|
return {ipaddress.ip_address(host)}
|
|
except ValueError:
|
|
pass
|
|
try:
|
|
return {
|
|
ipaddress.ip_address(address[4][0])
|
|
for address in socket.getaddrinfo(host, None, socket.AF_UNSPEC, socket.SOCK_STREAM)
|
|
}
|
|
except Exception:
|
|
return set()
|
|
|
|
|
|
def is_private_host(host: str) -> bool:
|
|
"""目标是否命中私网、回环或 IPv6 ULA/链路本地地址。"""
|
|
for address in resolve_host_ips(host):
|
|
if address.version == 4 and is_private_ipv4_int(int(address)):
|
|
return True
|
|
if address.version == 6 and (
|
|
address.is_loopback
|
|
or address.is_link_local
|
|
or address in ipaddress.ip_network("fc00::/7")
|
|
):
|
|
return True
|
|
return False
|