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Proxy code

Posted: Wed Dec 17, 2003 3:01 am
by kwag
Hello,

I need to write a small proxy server, where I can rewrite some headers with my own. I know this can be done with Squid or other cache programs, but I'd like to do it in PureBasic.
I've tried a link in this thread: viewtopic.php?t=3880&highlight=proxy but it's a dead link.
Anyone has done this in PB :?:
Any help (code samples) greatly appreciated.

Thanks,
-Karl

Posted: Wed Dec 17, 2003 3:33 pm
by thefool
it isnt a dead link. i can see the page.

Posted: Wed Dec 17, 2003 4:25 pm
by kwag
thefool wrote:it isnt a dead link. i can see the page.
The link in that thread is dead :!:
This one: viewtopic.php?t=151

-Karl

Posted: Thu Dec 18, 2003 5:06 pm
by kwag
OK, never mind, I think I got the hang of it :D
I'm using the example "NetworkServer.pb" as a guide, and also this Python code, which implements a proxy server:

Code: Select all

#!/bin/sh -
"exec" "python" "-O" "$0" "$@"

__doc__ = """Tiny HTTP Proxy.

This module implements GET, HEAD, POST, PUT and DELETE methods
on BaseHTTPServer, and behaves as an HTTP proxy.  The CONNECT
method is also implemented experimentally, but has not been
tested yet.

Any help will be greatly appreciated.SUZUKI Hisao
"""

__version__ = "0.2.1"

import BaseHTTPServer, select, socket, SocketServer, urlparse

class ProxyHandler (BaseHTTPServer.BaseHTTPRequestHandler):
    __base = BaseHTTPServer.BaseHTTPRequestHandler
    __base_handle = __base.handle

    server_version = "TinyHTTPProxy/" + __version__
    rbufsize = 0                        # self.rfile Be unbuffered

    def handle(self):
        (ip, port) =  self.client_address
        if hasattr(self, 'allowed_clients') and ip not in self.allowed_clients:
            self.raw_requestline = self.rfile.readline()
            if self.parse_request(): self.send_error(403)
        else:
            self.__base_handle()

    def _connect_to(self, netloc, soc):
        i = netloc.find(':')
        if i >= 0:
            host_port = netloc[:i], int(netloc[i+1:])
        else:
            host_port = netloc, 80
        print "\t" "connect to %s:%d" % host_port
        try: soc.connect(host_port)
        except socket.error, arg:
            try: msg = arg[1]
            except: msg = arg
            self.send_error(404, msg)
            return 0
        return 1

    def do_CONNECT(self):
        soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try:
            if self._connect_to(self.path, soc):
                self.log_request(200)
                self.wfile.write(self.protocol_version +
                                 " 200 Connection established\r\n")
                self.wfile.write("Proxy-agent: %s\r\n" % self.version_string())
                self.wfile.write("\r\n")
                self._read_write(soc, 300)
        finally:
            print "\t" "bye"
            soc.close()
            self.connection.close()

    def do_GET(self):
        (scm, netloc, path, params, query, fragment) = urlparse.urlparse(
            self.path, 'http')
        if scm != 'http' or fragment or not netloc:
            self.send_error(400, "bad url %s" % self.path)
            return
        soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try:
            if self._connect_to(netloc, soc):
                self.log_request()
                soc.send("%s %s %s\r\n" % (
                    self.command,
                    urlparse.urlunparse(('', '', path, params, query, '')),
                    self.request_version))
                self.headers['Connection'] = 'close'
                del self.headers['Proxy-Connection']
                for key_val in self.headers.items():
                    soc.send("%s: %s\r\n" % key_val)
                soc.send("\r\n")
                self._read_write(soc)
        finally:
            print "\t" "bye"
            soc.close()
            self.connection.close()

    def _read_write(self, soc, max_idling=20):
        iw = [self.connection, soc]
        ow = []
        count = 0
        while 1:
            count += 1
            (ins, _, exs) = select.select(iw, ow, iw, 3)
            if exs: break
            if ins:
                for i in ins:
                    if i is soc:
                        out = self.connection
                    else:
                        out = soc
                    data = i.recv(8192)
                    if data:
                        out.send(data)
                        count = 0
            else:
                print "\t" "idle", count
            if count == max_idling: break

    do_HEAD = do_GET
    do_POST = do_GET
    do_PUT  = do_GET
    do_DELETE=do_GET

class ThreadingHTTPServer (SocketServer.ThreadingMixIn,
                           BaseHTTPServer.HTTPServer): pass

if __name__ == '__main__':
    from sys import argv
    if argv[1:] and argv[1] in ('-h', '--help'):
        print argv[0], "[port [allowed_client_name ...]]"
    else:
        if argv[2:]:
            allowed = []
            for name in argv[2:]:
                client = socket.gethostbyname(name)
                allowed.append(client)
                print "Accept: %s (%s)" % (client, name)
            ProxyHandler.allowed_clients = allowed
            del argv[2:]
        else:
            print "Any clients will be served..."
        BaseHTTPServer.test(ProxyHandler, ThreadingHTTPServer)
Hope this code helps anyone that's trying to do what I'm trying to accomplish ;)

-Karl