import os
import socket
import struct
from typing import Optional
from urllib.parse import unquote, urlparse
from ._exceptions import WebSocketProxyException
"""
_url.py
websocket - WebSocket client library for Python
Copyright 2024 engn33r
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
__all__ = ["parse_url", "get_proxy_info"]
[docs]
def parse_url(url: str) -> tuple:
"""
parse url and the result is tuple of
(hostname, port, resource path and the flag of secure mode)
Parameters
----------
url: str
url string.
"""
if ":" not in url:
raise ValueError("url is invalid")
scheme, url = url.split(":", 1)
parsed = urlparse(url, scheme="http")
if parsed.hostname:
hostname = parsed.hostname
else:
raise ValueError("hostname is invalid")
port = 0
if parsed.port:
port = parsed.port
is_secure = False
if scheme == "ws":
if not port:
port = 80
elif scheme == "wss":
is_secure = True
if not port:
port = 443
else:
raise ValueError("scheme %s is invalid" % scheme)
if parsed.path:
resource = parsed.path
else:
resource = "/"
if parsed.query:
resource += f"?{parsed.query}"
return hostname, port, resource, is_secure
DEFAULT_NO_PROXY_HOST = ["localhost", "127.0.0.1"]
def _is_ip_address(addr: str) -> bool:
try:
socket.inet_aton(addr)
except socket.error:
return False
else:
return True
def _is_subnet_address(hostname: str) -> bool:
try:
addr, netmask = hostname.split("/")
return _is_ip_address(addr) and 0 <= int(netmask) < 32
except ValueError:
return False
def _is_address_in_network(ip: str, net: str) -> bool:
ipaddr: int = struct.unpack("!I", socket.inet_aton(ip))[0]
netaddr, netmask = net.split("/")
netaddr: int = struct.unpack("!I", socket.inet_aton(netaddr))[0]
netmask = (0xFFFFFFFF << (32 - int(netmask))) & 0xFFFFFFFF
return ipaddr & netmask == netaddr
def _is_no_proxy_host(hostname: str, no_proxy: Optional[list]) -> bool:
if not no_proxy:
if v := os.environ.get("no_proxy", os.environ.get("NO_PROXY", "")).replace(
" ", ""
):
no_proxy = v.split(",")
if not no_proxy:
no_proxy = DEFAULT_NO_PROXY_HOST
if "*" in no_proxy:
return True
if hostname in no_proxy:
return True
if _is_ip_address(hostname):
return any(
[
_is_address_in_network(hostname, subnet)
for subnet in no_proxy
if _is_subnet_address(subnet)
]
)
for domain in [domain for domain in no_proxy if domain.startswith(".")]:
if hostname.endswith(domain):
return True
return False
[docs]
def get_proxy_info(
hostname: str,
is_secure: bool,
proxy_host: Optional[str] = None,
proxy_port: int = 0,
proxy_auth: Optional[tuple] = None,
no_proxy: Optional[list] = None,
proxy_type: str = "http",
) -> tuple:
"""
Try to retrieve proxy host and port from environment
if not provided in options.
Result is (proxy_host, proxy_port, proxy_auth).
proxy_auth is tuple of username and password
of proxy authentication information.
Parameters
----------
hostname: str
Websocket server name.
is_secure: bool
Is the connection secure? (wss) looks for "https_proxy" in env
instead of "http_proxy"
proxy_host: str
http proxy host name.
proxy_port: str or int
http proxy port.
no_proxy: list
Whitelisted host names that don't use the proxy.
proxy_auth: tuple
HTTP proxy auth information. Tuple of username and password. Default is None.
proxy_type: str
Specify the proxy protocol (http, socks4, socks4a, socks5, socks5h). Default is "http".
Use socks4a or socks5h if you want to send DNS requests through the proxy.
"""
if _is_no_proxy_host(hostname, no_proxy):
return None, 0, None
if proxy_host:
if not proxy_port:
raise WebSocketProxyException("Cannot use port 0 when proxy_host specified")
port = proxy_port
auth = proxy_auth
return proxy_host, port, auth
env_key = "https_proxy" if is_secure else "http_proxy"
value = os.environ.get(env_key, os.environ.get(env_key.upper(), "")).replace(
" ", ""
)
if value:
proxy = urlparse(value)
auth = (
(unquote(proxy.username), unquote(proxy.password))
if proxy.username
else None
)
return proxy.hostname, proxy.port, auth
return None, 0, None