v0.0.1

.gitignore

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+.*/
+__pycache__/

LICENSE

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+MIT License
+Copyright (c) <2024> <Gregory Lirent>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+## Simple Proxy Auto Configuration (PAC) Server
+
+This server supports to split the configuration for clients by IP.
+
+> Run:
+> `/path/to/python3 main.py --config /path/to/config/file.yml --host 0.0.0.0 --port 3000`

app/__init__.py

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+# This software is licensed by the MIT License, see LICENSE file
+#                                Copyright © 2024 Gregory Lirent
+
+from fastapi import FastAPI, Request, Response, HTTPException
+from .models import PACContent
+
+pac: PACContent | None = None
+app = FastAPI()
+
+
+def init(filename: str | None = None):
+    global pac
+
+    if not filename:
+        pac = None
+    else:
+        pac = PACContent(filename)
+
+
+@app.get("/")
+async def root(request: Request, view: bool = False):
+    if not pac:
+        raise HTTPException(status_code=500, detail="Config is not set")
+
+    print(request.headers.get('X-Real-IP', None) or request.client.host)
+
+    return Response(status_code=200, media_type="application/javascript",
+                    content=pac.render_for(request.headers.get('X-Real-IP', None) or request.client.host),
+                    headers=None if view else {"Content-Disposition": "attachment; filename=wpad.dat"})

app/models.py

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+# This software is licensed by the MIT License, see LICENSE file
+#                                Copyright © 2024 Gregory Lirent
+
+import time
+import os
+import yaml
+from typing import List
+from ipaddress import ip_network, IPv4Network, IPv4Address, IPv6Network, IPv6Address
+from enum import Enum
+
+
+class LogLevel(Enum):
+    critical = 'critical'
+    error = 'error'
+    warning = 'warning'
+    info = 'info'
+    debug = 'debug'
+    trace = 'trace'
+
+    def __str__(self):
+        return self.value
+
+
+class Proxy:
+
+    @staticmethod
+    def __in_net(net: IPv4Network | IPv6Network, dest: IPv4Network | IPv6Network) -> bool:
+        return net.network_address in dest and net.broadcast_address in dest
+
+    @staticmethod
+    def __fetch_networks(net_list: List[str]) -> List[IPv4Network | IPv6Network]:
+        networks = []
+        if net_list:
+            for net in net_list:
+                networks.append(ip_network(net))
+        return networks
+
+    @property
+    def name(self):
+        return f'proxy{hash(self)}'
+
+    @property
+    def function_name(self):
+        return f'is{self.name.capitalize()}'
+
+    @property
+    def host(self):
+        return self.__host
+
+    @property
+    def port(self) -> int:
+        return self.__port
+
+    def is_allowed_from(self, net: str | IPv4Address | IPv6Address | IPv4Network | IPv6Network) -> bool:
+        if isinstance(net, (str, IPv4Address, IPv4Network)):
+            net = ip_network(str(net))
+
+        if self.__deny:
+            for dest in self.__deny:
+                if self.__in_net(net, dest):
+                    return False
+
+        if not self.__allow:
+            return True
+
+        for dest in self.__allow:
+            if net.network_address in dest and net.broadcast_address in dest:
+                return True
+        return False
+
+    def render(self):
+        content = f'function is{self.name}(h) {{\n'
+        for target in self.__targets:
+            content += f'\tif (shExpMatch(h, "{target}")) return true;\n'
+        return f'{content}\treturn false;\n}}'
+
+    def __hash__(self):
+        return abs(hash(str(self)))
+
+    def __str__(self):
+        return f'PROXY {self.__host}:{self.__port}'
+
+    def __init__(self, *, host: str, port: int,
+                 allow: List[str] | None = None,
+                 deny: List[str] | None = None,
+                 targets: List[str] | None = None):
+
+        self.__host    = host
+        self.__port    = port
+        self.__allow   = self.__fetch_networks(allow)
+        self.__deny    = self.__fetch_networks(deny)
+        self.__targets = targets if targets else []
+
+        if not self.__host or not self.__port:
+            raise ValueError("Proxy's host and port cannot be empty")
+        if not self.__targets:
+            raise ValueError("Pointless proxy")
+
+
+class PACContent:
+
+    @property
+    def proxies(self) -> List[Proxy]:
+        if not os.path.exists(self.__filename):
+            return []
+
+        if os.stat(self.__filename).st_mtime >= self.__atime:
+            with open(self.__filename, "r") as fd:
+                conf: dict = yaml.safe_load(fd)
+
+            self.__atime   = int(time.time())
+            self.__proxies = []
+            for proxy in conf.get('proxy_servers', []):
+                try:
+                    self.__proxies.append(Proxy(**proxy))
+                except ValueError:
+                    pass
+
+        return self.__proxies
+
+    def render_for(self, net: str | IPv4Address | IPv6Address | IPv6Network | IPv4Network):
+        f_blocks = []
+        p_blocks = ["function FindProxyForURL(url, host) {"]
+
+        for proxy in self.proxies:
+            if proxy.is_allowed_from(net):
+                f_blocks.append(proxy.render())
+                p_blocks.append(f'\tif ({proxy.function_name}(host) return "{str(proxy)}";')
+        p_blocks.append('\treturn "DIRECT";\n}')
+        f_blocks.append("\n".join(p_blocks))
+
+        return "\n\n".join(f_blocks)
+
+    def __init__(self, filename: str):
+        self.__filename = filename
+        self.__atime    = 0
+        self.__proxies  = []

config.example.yml

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+proxy_servers:
+  - host: '127.0.0.1'
+    port: 8118
+    allow:
+      - '127.0.0.0/8'
+    deny:
+      - '127.0.1.0/24'
+    targets:
+      - 'rutracker.org'
+      - '*.rutracker.org'

main.py

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+#!/usr/bin/env python
+
+# This software is licensed by the MIT License, see LICENSE file
+#                                Copyright © 2024 Gregory Lirent
+
+import os
+import uvicorn
+from app import app, init
+from app.models import LogLevel
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser(description="PAC web server")
+
+    parser.add_argument('-H', '--host', type=str, default="localhost",
+                        help='web server host (default: localhost)')
+    parser.add_argument('-p', "--port", type=int, default=3000,
+                        help='web server port (default: 3000)')
+
+    parser.add_argument('--log_level', type=LogLevel, choices=list(LogLevel), default=LogLevel.info)
+
+    parser.add_argument('-c', '--config', type=str, default="", help='config file')
+
+    args = parser.parse_args()
+
+    init(args.config or os.environ.get("PAC_CONFIG_FILE", None))
+
+    uvicorn.run(app, host=args.host, port=args.port, log_level=str(args.log_level), use_colors=True)

requirements.txt

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+fastapi>=0.111.0
+uvicorn>=0.30.0
+aiofiles>=23.2.1
+PyYAML>=6.0.1