"""I hold resource classes and helper classes that deal with CGI scripts.
"""
import string
import os
import sys
import urllib
from twisted.protocols import http
from twisted.internet import reactor, protocol
from twisted.spread import pb
from twisted.python import log, filepath
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, "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 = []
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
for key, value in os.environ.items():
if not env.has_key(key):
env[key] = value
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 = ''
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
"""
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]
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]) 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()