# Copyright (c) 2001-2004 Twisted Matrix Laboratories. # See LICENSE for details. """I hold resource classes and helper classes that deal with CGI scripts. """ # System Imports import string import os import sys import urllib # Twisted Imports from twisted.web import http from twisted.internet import reactor, protocol from twisted.spread import pb from twisted.python import log, filepath # Sibling Imports import server import error import html import resource import static from server import NOT_DONE_YET class CGIDirectory(resource.Resource, filepath.FilePath): def __init__(self, pathname): resource.Resource.__init__(self) filepath.FilePath.__init__(self, pathname) def getChild(self, path, request): fnp = self.child(path) if not fnp.exists(): return static.File.childNotFound elif fnp.isdir(): return CGIDirectory(fnp.path) else: return CGIScript(fnp.path) return error.NoResource() def render(self, request): return error.NoResource("CGI directories do not support directory listing.").render(request) class CGIScript(resource.Resource): """I represent a CGI script. My implementation is complex due to the fact that it requires asynchronous IPC with an external process with an unpleasant protocol. """ isLeaf = 1 def __init__(self, filename, registry=None): """Initialize, with the name of a CGI script file. """ self.filename = filename def render(self, request): """Do various things to conform to the CGI specification. I will set up the usual slew of environment variables, then spin off a process. """ script_name = "/"+string.join(request.prepath, '/') python_path = string.join(sys.path, os.pathsep) serverName = string.split(request.getRequestHostname(), ':')[0] env = {"SERVER_SOFTWARE": server.version, "SERVER_NAME": serverName, "GATEWAY_INTERFACE": "CGI/1.1", "SERVER_PROTOCOL": request.clientproto, "SERVER_PORT": str(request.getHost()[2]), "REQUEST_METHOD": request.method, "SCRIPT_NAME": script_name, # XXX "SCRIPT_FILENAME": self.filename, "REQUEST_URI": request.uri, } client = request.getClient() if client is not None: env['REMOTE_HOST'] = client ip = request.getClientIP() if ip is not None: env['REMOTE_ADDR'] = ip pp = request.postpath if pp: env["PATH_INFO"] = "/"+string.join(pp, '/') qindex = string.find(request.uri, '?') if qindex != -1: qs = env['QUERY_STRING'] = request.uri[qindex+1:] if '=' in qs: qargs = [] else: qargs = [urllib.unquote(x) for x in qs.split('+')] else: env['QUERY_STRING'] = '' qargs = [] # Propogate HTTP headers for title, header in request.getAllHeaders().items(): envname = string.upper(string.replace(title, '-', '_')) if title not in ('content-type', 'content-length'): envname = "HTTP_" + envname env[envname] = header # Propogate our environment for key, value in os.environ.items(): if not env.has_key(key): env[key] = value # And they're off! self.runProcess(env, request, qargs) return NOT_DONE_YET def runProcess(self, env, request, qargs=[]): p = CGIProcessProtocol(request) reactor.spawnProcess(p, self.filename, [self.filename]+qargs, env, os.path.dirname(self.filename)) class FilteredScript(CGIScript): """I am a special version of a CGI script, that uses a specific executable. This is useful for interfacing with other scripting languages that adhere to the CGI standard (cf. PHPScript). My 'filter' attribute specifies what executable to run, and my 'filename' init parameter describes which script to pass to the first argument of that script. """ filter = '/usr/bin/cat' def runProcess(self, env, request, qargs=[]): p = CGIProcessProtocol(request) reactor.spawnProcess(p, self.filter, [self.filter, self.filename]+qargs, env, os.path.dirname(self.filename)) class PHP3Script(FilteredScript): """I am a FilteredScript that uses the default PHP3 command on most systems. """ filter = '/usr/bin/php3' class PHPScript(FilteredScript): """I am a FilteredScript that uses the PHP command on most systems. Sometimes, php wants the path to itself as argv[0]. This is that time. """ filter = '/usr/bin/php4' class CGIProcessProtocol(protocol.ProcessProtocol, pb.Viewable): handling_headers = 1 headers_written = 0 headertext = '' errortext = '' # Remotely relay producer interface. def view_resumeProducing(self, issuer): self.resumeProducing() def view_pauseProducing(self, issuer): self.pauseProducing() def view_stopProducing(self, issuer): self.stopProducing() def resumeProducing(self): self.transport.resumeProducing() def pauseProducing(self): self.transport.pauseProducing() def stopProducing(self): self.transport.loseConnection() def __init__(self, request): self.request = request def connectionMade(self): self.request.registerProducer(self, 1) self.request.content.seek(0, 0) content = self.request.content.read() if content: self.transport.write(content) def errReceived(self, error): self.errortext = self.errortext + error def outReceived(self, output): """ Handle a chunk of input """ # First, make sure that the headers from the script are sorted # out (we'll want to do some parsing on these later.) if self.handling_headers: text = self.headertext + output headerEnds = [] for delimiter in '\n\n','\r\n\r\n','\r\r', '\n\r\n': headerend = string.find(text,delimiter) if headerend != -1: headerEnds.append((headerend, delimiter)) if headerEnds: headerEnds.sort() headerend, delimiter = headerEnds[0] self.headertext = text[:headerend] # This is a final version of the header text. linebreak = delimiter[:len(delimiter)/2] headers = string.split(self.headertext, linebreak) for header in headers: br = string.find(header,': ') if br == -1: log.msg( 'ignoring malformed CGI header: %s' % header ) else: headerName = string.lower(header[:br]) headerText = header[br+2:] if headerName == 'location': self.request.setResponseCode(http.FOUND) if headerName == 'status': try: statusNum = int(headerText[:3]) #"XXX " sometimes happens. except: log.msg( "malformed status header" ) else: self.request.setResponseCode(statusNum) else: self.request.setHeader(headerName,headerText) output = text[headerend+len(delimiter):] self.handling_headers = 0 if self.handling_headers: self.headertext = text if not self.handling_headers: self.request.write(output) def processEnded(self, reason): if reason.value.exitCode != 0: log.msg("CGI %s exited with exit code %s" % (self.request.uri, reason.value.exitCode)) if self.errortext: log.msg("Errors from CGI %s: %s" % (self.request.uri, self.errortext)) if self.handling_headers: log.msg("Premature end of headers in %s: %s" % (self.request.uri, self.headertext)) self.request.write( error.ErrorPage(http.INTERNAL_SERVER_ERROR, "CGI Script Error", "Premature end of script headers.").render(self.request)) self.request.unregisterProducer() self.request.finish()