269 lines
8.4 KiB
Python
269 lines
8.4 KiB
Python
# A simple proxy server
|
|
# by Humans for All
|
|
#
|
|
# Listens on the specified port (defaults to squids 3128)
|
|
# * if a url query is got (http://localhost:3128/?url=http://site.of.interest/path/of/interest)
|
|
# fetches the contents of the specified url and returns the same to the requester
|
|
#
|
|
|
|
|
|
import sys
|
|
import http.server
|
|
import urllib.parse
|
|
import urllib.request
|
|
from dataclasses import dataclass
|
|
import html.parser
|
|
|
|
|
|
gMe = {
|
|
'--port': 3128,
|
|
'--config': '/dev/null',
|
|
'server': None
|
|
}
|
|
|
|
|
|
class ProxyHandler(http.server.BaseHTTPRequestHandler):
|
|
|
|
# Common headers to include in responses from this server
|
|
def send_headers_common(self):
|
|
self.send_header('Access-Control-Allow-Origin', '*')
|
|
self.send_header('Access-Control-Allow-Methods', 'GET, OPTIONS')
|
|
self.send_header('Access-Control-Allow-Headers', '*')
|
|
self.end_headers()
|
|
|
|
# overrides the SendError helper
|
|
# so that the common headers mentioned above can get added to them
|
|
# else CORS failure will be triggered by the browser on fetch from browser.
|
|
def send_error(self, code: int, message: str | None = None, explain: str | None = None) -> None:
|
|
self.send_response(code, message)
|
|
self.send_headers_common()
|
|
|
|
# Handle GET requests
|
|
def do_GET(self):
|
|
print(f"DBUG:ProxyHandler:GET:{self.path}")
|
|
pr = urllib.parse.urlparse(self.path)
|
|
print(f"DBUG:ProxyHandler:GET:{pr}")
|
|
match pr.path:
|
|
case '/urlraw':
|
|
handle_urlraw(self, pr)
|
|
case '/urltext':
|
|
handle_urltext(self, pr)
|
|
case '/aum':
|
|
handle_aum(self, pr)
|
|
case _:
|
|
print(f"WARN:ProxyHandler:GET:UnknownPath{pr.path}")
|
|
self.send_error(400, f"WARN:UnknownPath:{pr.path}")
|
|
|
|
# Handle OPTIONS for CORS preflights (just in case from browser)
|
|
def do_OPTIONS(self):
|
|
print(f"DBUG:ProxyHandler:OPTIONS:{self.path}")
|
|
self.send_response(200)
|
|
self.send_headers_common()
|
|
|
|
|
|
def handle_aum(ph: ProxyHandler, pr: urllib.parse.ParseResult):
|
|
ph.send_response_only(200, "bharatavarshe")
|
|
ph.send_header('Access-Control-Allow-Origin', '*')
|
|
ph.end_headers()
|
|
|
|
|
|
@dataclass(frozen=True)
|
|
class UrlReqResp:
|
|
callOk: bool
|
|
httpStatus: int
|
|
httpStatusMsg: str = ""
|
|
contentType: str = ""
|
|
contentData: str = ""
|
|
|
|
|
|
def handle_urlreq(pr: urllib.parse.ParseResult, tag: str):
|
|
print(f"DBUG:{tag}:{pr}")
|
|
queryParams = urllib.parse.parse_qs(pr.query)
|
|
url = queryParams['url']
|
|
print(f"DBUG:{tag}:Url:{url}")
|
|
url = url[0]
|
|
if (not url) or (len(url) == 0):
|
|
return UrlReqResp(False, 400, f"WARN:{tag}:MissingUrl")
|
|
try:
|
|
# Get requested url
|
|
with urllib.request.urlopen(url, timeout=10) as response:
|
|
contentData = response.read().decode('utf-8')
|
|
statusCode = response.status or 200
|
|
contentType = response.getheader('Content-Type') or 'text/html'
|
|
return UrlReqResp(True, statusCode, "", contentType, contentData)
|
|
except Exception as exc:
|
|
return UrlReqResp(False, 502, f"WARN:UrlFetchFailed:{exc}")
|
|
|
|
|
|
def handle_urlraw(ph: ProxyHandler, pr: urllib.parse.ParseResult):
|
|
try:
|
|
# Get requested url
|
|
got = handle_urlreq(pr, "HandleUrlRaw")
|
|
if not got.callOk:
|
|
ph.send_error(got.httpStatus, got.httpStatusMsg)
|
|
return
|
|
# Send back to client
|
|
ph.send_response(got.httpStatus)
|
|
ph.send_header('Content-Type', got.contentType)
|
|
# Add CORS for browser fetch, just in case
|
|
ph.send_header('Access-Control-Allow-Origin', '*')
|
|
ph.end_headers()
|
|
ph.wfile.write(got.contentData.encode('utf-8'))
|
|
except Exception as exc:
|
|
ph.send_error(502, f"WARN:UrlFetchFailed:{exc}")
|
|
|
|
|
|
class TextHtmlParser(html.parser.HTMLParser):
|
|
|
|
def __init__(self):
|
|
super().__init__()
|
|
self.inside = {
|
|
'body': False,
|
|
'script': False,
|
|
'style': False,
|
|
'header': False,
|
|
'footer': False,
|
|
'nav': False
|
|
}
|
|
self.monitored = [ 'body', 'script', 'style', 'header', 'footer', 'nav' ]
|
|
self.bCapture = False
|
|
self.text = ""
|
|
self.textStripped = ""
|
|
|
|
def do_capture(self):
|
|
if self.inside['body'] and not (self.inside['script'] or self.inside['style'] or self.inside['header'] or self.inside['footer'] or self.inside['nav']):
|
|
return True
|
|
return False
|
|
|
|
def handle_starttag(self, tag: str, attrs: list[tuple[str, str | None]]):
|
|
if tag in self.monitored:
|
|
self.inside[tag] = True
|
|
|
|
def handle_endtag(self, tag: str):
|
|
if tag in self.monitored:
|
|
self.inside[tag] = False
|
|
|
|
def handle_data(self, data: str):
|
|
if self.do_capture():
|
|
self.text += f"{data}\n"
|
|
|
|
def syncup(self):
|
|
self.textStripped = self.text
|
|
|
|
def strip_adjacent_newlines(self):
|
|
oldLen = -99
|
|
newLen = len(self.textStripped)
|
|
aStripped = self.textStripped;
|
|
while oldLen != newLen:
|
|
oldLen = newLen
|
|
aStripped = aStripped.replace("\n\n\n","\n")
|
|
newLen = len(aStripped)
|
|
self.textStripped = aStripped
|
|
|
|
def strip_whitespace_lines(self):
|
|
aLines = self.textStripped.splitlines()
|
|
self.textStripped = ""
|
|
for line in aLines:
|
|
if (len(line.strip())==0):
|
|
self.textStripped += "\n"
|
|
continue
|
|
self.textStripped += f"{line}\n"
|
|
|
|
def get_stripped_text(self):
|
|
self.syncup()
|
|
self.strip_whitespace_lines()
|
|
self.strip_adjacent_newlines()
|
|
return self.textStripped
|
|
|
|
|
|
def handle_urltext(ph: ProxyHandler, pr: urllib.parse.ParseResult):
|
|
try:
|
|
# Get requested url
|
|
got = handle_urlreq(pr, "HandleUrlText")
|
|
if not got.callOk:
|
|
ph.send_error(got.httpStatus, got.httpStatusMsg)
|
|
return
|
|
# Extract Text
|
|
textHtml = TextHtmlParser()
|
|
textHtml.feed(got.contentData)
|
|
# Send back to client
|
|
ph.send_response(got.httpStatus)
|
|
ph.send_header('Content-Type', got.contentType)
|
|
# Add CORS for browser fetch, just in case
|
|
ph.send_header('Access-Control-Allow-Origin', '*')
|
|
ph.end_headers()
|
|
ph.wfile.write(textHtml.get_stripped_text().encode('utf-8'))
|
|
except Exception as exc:
|
|
ph.send_error(502, f"WARN:UrlFetchFailed:{exc}")
|
|
|
|
|
|
def load_config():
|
|
"""
|
|
Allow loading of a json based config file
|
|
|
|
The config entries should be named same as their equivalent cmdline argument
|
|
entries but without the -- prefix. They will be loaded into gMe after adding
|
|
-- prefix.
|
|
|
|
As far as the program is concerned the entries could either come from cmdline
|
|
or from a json based config file.
|
|
"""
|
|
global gMe
|
|
import json
|
|
with open(gMe['--config']) as f:
|
|
cfg = json.load(f)
|
|
for k in cfg:
|
|
gMe[f"--{k}"] = cfg[k]
|
|
|
|
|
|
def process_args(args: list[str]):
|
|
global gMe
|
|
gMe['INTERNAL.ProcessArgs.Malformed'] = []
|
|
gMe['INTERNAL.ProcessArgs.Unknown'] = []
|
|
iArg = 1
|
|
while iArg < len(args):
|
|
cArg = args[iArg]
|
|
if (not cArg.startswith("--")):
|
|
gMe['INTERNAL.ProcessArgs.Malformed'].append(cArg)
|
|
print(f"WARN:ProcessArgs:{iArg}:IgnoringMalformedCommandOr???:{cArg}")
|
|
iArg += 1
|
|
continue
|
|
match cArg:
|
|
case '--port':
|
|
iArg += 1
|
|
gMe[cArg] = int(args[iArg])
|
|
iArg += 1
|
|
case '--config':
|
|
iArg += 1
|
|
gMe[cArg] = args[iArg]
|
|
iArg += 1
|
|
load_config()
|
|
case _:
|
|
gMe['INTERNAL.ProcessArgs.Unknown'].append(cArg)
|
|
print(f"WARN:ProcessArgs:{iArg}:IgnoringUnknownCommand:{cArg}")
|
|
iArg += 1
|
|
print(gMe)
|
|
|
|
|
|
def run():
|
|
try:
|
|
gMe['serverAddr'] = ('', gMe['--port'])
|
|
gMe['server'] = http.server.HTTPServer(gMe['serverAddr'], ProxyHandler)
|
|
print(f"INFO:Run:Starting on {gMe['serverAddr']}")
|
|
gMe['server'].serve_forever()
|
|
except KeyboardInterrupt:
|
|
print("INFO:Run:Shuting down...")
|
|
if (gMe['server']):
|
|
gMe['server'].server_close()
|
|
sys.exit(0)
|
|
except Exception as exc:
|
|
print(f"ERRR:Run:Exiting:Exception:{exc}")
|
|
if (gMe['server']):
|
|
gMe['server'].server_close()
|
|
sys.exit(1)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
process_args(sys.argv)
|
|
run()
|