fast如何过滤域名

from fastapi import FastAPI, Request, HTTPException
import re

app = FastAPI()

# 白名单域名列表
WHITELISTED_DOMAINS = ["example.com", "api.example.com"]

# 黑名单域名列表
BLACKLISTED_DOMAINS = ["malicious.com"]

@app.middleware("http")
async def domain_filter(request: Request, call_next):
    host = request.headers.get("host")
    
    if not host:
        raise HTTPException(status_code=400, detail="Host header is missing")
    
    # 白名单过滤
    if WHITELISTED_DOMAINS and host not in WHITELISTED_DOMAINS:
        raise HTTPException(status_code=403, detail="Domain not allowed")
    
    # 黑名单过滤
    if BLACKLISTED_DOMAINS and host in BLACKLISTED_DOMAINS:
        raise HTTPException(status_code=403, detail="Domain is blacklisted")
    
    # 正则表达式过滤
    regex_pattern = r"^api\..*\.example\.com$"
    if re.match(regex_pattern, host):
        raise HTTPException(status_code=403, detail="Regex pattern matched")
    
    response = await call_next(request)
    return response

@app.get("/")
async def read_root():
    return {"message": "Hello World"}