import SimpleAsyncServer # ============================================================= # An implementation of the HTTP protocol, supporting persistent # connections and CGI # ============================================================= import sys import os import traceback import datetime import mimetypes import urlparse import urllib import cStringIO class HTTP(SimpleAsyncServer.ClientHandler): # parameters to override if necessary root = os.getcwd() # the directory to serve files from cgi_directories = ['/cgi-bin'] # subdirectories for cgi scripts logging = True # print logging info for each request ? blocksize = 2 << 16 # size of blocks to read from files and send def request_complete(self): """In the HTTP protocol, a request is complete if the "end of headers" sequence ('\r\n\r\n') has been received If the request is POST, stores the request body in a StringIO before returning True""" terminator = self.incoming.find('\r\n\r\n') if terminator == -1: return False lines = self.incoming[:terminator].split('\r\n') self.requestline = lines[0] try: self.method,self.url,self.protocol = lines[0].strip().split() except: self.method = None # indicates bad request return True # put request headers in a dictionary self.headers = {} for line in lines[1:]: k,v = line.split(':',1) self.headers[k.lower().strip()] = v.strip() # persistent connection close_conn = self.headers.get("connection","") if (self.protocol == "HTTP/1.1" and close_conn.lower() == "keep-alive"): self.close_when_done = False # parse the url scheme,netloc,path,params,query,fragment = urlparse.urlparse(self.url) self.path, = path,(params,query,fragment) if self.method == 'POST': # for POST requests, read the request body # its length must be specified in the content-length header content_length = int(self.headers.get('content-length',0)) body = self.incoming[terminator+4:] # request is incomplete if not all message body received if len(body) HTTP.blocksize: resp_string = resp_line + resp_headers resp_file = open(file_name,'rb') else: resp_string = resp_line + resp_headers + \ open(file_name,'rb').read() response = [resp_string] if resp_file: response.append(resp_file) self.log(200) return response def translate_path(self): """Translate URL path into a path in the file system""" return os.path.join(HTTP.root,*self.path.split('/')) def managed(self): """Test if the request can be processed by a specific method If so, set self.mngt_method to the method used This implementation tests if the script is in a cgi directory""" if self.is_cgi(): self.mngt_method = self.run_cgi return True return False def is_cgi(self): """Test if url in a cgi directory""" for path in self.cgi_directories: if self.path.startswith(path): rest = self.path[len(path):] if not rest or rest.startswith('/'): return True return False def run_cgi(self): # set CGI environment variables self.make_cgi_env() # redirect print statements to a cStringIO save_stdout = sys.stdout sys.stdout = cStringIO.StringIO() # run the script try: execfile(self.file_name) except: sys.stdout = cStringIO.StringIO() sys.stdout.write("Content-type:text/plain\r\n\r\n") traceback.print_exc(file=sys.stdout) response = sys.stdout.getvalue() if self.method == "HEAD": # for HEAD request, don't send message body even if the script # returns one (RFC 3875) head_lines = [] for line in response.split('\n'): if not line: break head_lines.append(line) response = '\n'.join(head_lines) sys.stdout = save_stdout # restore sys.stdout # close connection in case there is no content-length header self.close_when_done = True resp_line = "%s 200 Ok\r\n" %self.protocol return [resp_line + response] def make_cgi_env(self): """Set CGI environment variables""" env = {} env['SERVER_SOFTWARE'] = "AsyncServer" env['SERVER_NAME'] = "AsyncServer" env['GATEWAY_INTERFACE'] = 'CGI/1.1' env['DOCUMENT_ROOT'] = HTTP.root env['SERVER_PROTOCOL'] = "HTTP/1.1" env['SERVER_PORT'] = str(self.server.port) env['REQUEST_METHOD'] = self.method env['REQUEST_URI'] = self.url env['PATH_TRANSLATED'] = self.translate_path() env['SCRIPT_NAME'] = self.path env['PATH_INFO'] = urlparse.urlunparse(("","","",[0],"","")) env['QUERY_STRING'] =[1] if not == self.client_address[0]: env['REMOTE_HOST'] = env['REMOTE_ADDR'] = self.client_address[0] env['CONTENT_LENGTH'] = str(self.headers.get('content-length','')) for k in ['USER_AGENT','COOKIE','ACCEPT','ACCEPT_CHARSET', 'ACCEPT_ENCODING','ACCEPT_LANGUAGE','CONNECTION']: hdr = k.lower().replace("_","-") env['HTTP_%s' %k.upper()] = str(self.headers.get(hdr,'')) os.environ.update(env) def err_resp(self,code,msg): """Return an error message""" resp_line = "%s %s %s\r\n" %(self.protocol,code,msg) self.close_when_done = True self.log(code) return [resp_line] def log(self,code): """Write a trace of the request on stderr""" if HTTP.logging: date_str ='[%d/%b/%Y %H:%M:%S]') sys.stderr.write('%s - - %s "%s" %s\n' %(, date_str,self.requestline,code)) if __name__=="__main__": # launch the server on the specified port port = 8081 print "Asynchronous HTTP server running on port %s" %port print "Press Ctrl+C to stop" server = SimpleAsyncServer.Server('', port) HTTP.logging = False try: SimpleAsyncServer.loop(server,HTTP) except KeyboardInterrupt: for s in server.client_handlers: server.close_client(s) print 'Ctrl+C pressed. Closing'