#!/bin/env python
#------------------------------------------------------------------------
#               Copyright (c) 1998 by Total Control Software
#                         All Rights Reserved
#------------------------------------------------------------------------
#
# Module Name:  fcgi.py
#
# Description:  Handles communication with the FastCGI module of the
#               web server without using the FastCGI developers kit, but
#               will also work in a non-FastCGI environment, (straight CGI.)
#               This module was originally fetched from someplace on the
#               Net (I don't remember where and I can't find it now...) and
#               has been significantly modified to fix several bugs, be more
#               readable, more robust at handling large CGI data and return
#               document sizes, and also to fit the model that we had previously
#               used for FastCGI.
#
#     WARNING:  If you don't know what you are doing, don't tinker with this
#               module!
#
# Creation Date:    1/30/98 2:59:04PM
#
# License:      This is free software.  You may use this software for any
#               purpose including modification/redistribution, so long as
#               this header remains intact and that you do not claim any
#               rights of ownership or authorship of this software.  This
#               software has been tested, but no warranty is expressed or
#               implied.
#
#------------------------------------------------------------------------


import os, sys, socket, errno
from cStringIO import StringIO
import cgi

#---------------------------------------------------------------------------

# Set various FastCGI constants
# Maximum number of requests that can be handled
FCGI_MAX_REQS=1
FCGI_MAX_CONNS = 1

# Supported version of the FastCGI protocol
FCGI_VERSION_1 = 1

# Boolean: can this application multiplex connections?
FCGI_MPXS_CONNS=0

# Record types
FCGI_BEGIN_REQUEST = 1 ; FCGI_ABORT_REQUEST = 2 ; FCGI_END_REQUEST   = 3
FCGI_PARAMS        = 4 ; FCGI_STDIN         = 5 ; FCGI_STDOUT        = 6
FCGI_STDERR        = 7 ; FCGI_DATA          = 8 ; FCGI_GET_VALUES    = 9
FCGI_GET_VALUES_RESULT = 10
FCGI_UNKNOWN_TYPE = 11
FCGI_MAXTYPE = FCGI_UNKNOWN_TYPE

# Types of management records
ManagementTypes = [FCGI_GET_VALUES]

FCGI_NULL_REQUEST_ID=0

# Masks for flags component of FCGI_BEGIN_REQUEST
FCGI_KEEP_CONN = 1

# Values for role component of FCGI_BEGIN_REQUEST
FCGI_RESPONDER = 1 ; FCGI_AUTHORIZER = 2 ; FCGI_FILTER = 3

# Values for protocolStatus component of FCGI_END_REQUEST
FCGI_REQUEST_COMPLETE = 0               # Request completed nicely
FCGI_CANT_MPX_CONN    = 1               # This app can't multiplex
FCGI_OVERLOADED       = 2               # New request rejected; too busy
FCGI_UNKNOWN_ROLE     = 3               # Role value not known


error = 'fcgi.error'


#---------------------------------------------------------------------------

# The following function is used during debugging; it isn't called
# anywhere at the moment

def error(msg):
	"Append a string to /tmp/err"
	errf = open('/tmp/err', 'a+')
	errf.write(msg+'\n')
	errf.close()

#---------------------------------------------------------------------------

class record:
	"Class representing FastCGI records"
	def __init__(self):
		self.version = FCGI_VERSION_1
		self.recType = FCGI_UNKNOWN_TYPE
		self.reqId   = FCGI_NULL_REQUEST_ID
		self.content = ""

	#----------------------------------------
	def readRecord(self, sock):
		s = map(ord, sock.recv(8))
		self.version, self.recType, paddingLength = s[0], s[1], s[6]
		self.reqId, contentLength = (s[2]<<8)+s[3], (s[4]<<8)+s[5]
		self.content = ""
		while len(self.content) < contentLength:
			data = sock.recv(contentLength - len(self.content))
			self.content = self.content + data
		if paddingLength != 0:
			padding = sock.recv(paddingLength)

		# Parse the content information
		c = self.content
		if self.recType == FCGI_BEGIN_REQUEST:
			self.role = (ord(c[0])<<8) + ord(c[1])
			self.flags = ord(c[2])

		elif self.recType == FCGI_UNKNOWN_TYPE:
			self.unknownType = ord(c[0])

		elif self.recType == FCGI_GET_VALUES or self.recType == FCGI_PARAMS:
			self.values = {}
			pos = 0
			while pos < len(c):
				name, value, pos = readPair(c, pos)
				self.values[name] = value
		elif self.recType == FCGI_END_REQUEST:
			b = map(ord, c[0:4])
			self.appStatus = (b[0]<<24) + (b[1]<<16) + (b[2]<<8) + b[3]
			self.protocolStatus = ord(c[4])

	#----------------------------------------
	def writeRecord(self, sock):
		content = self.content
		if self.recType == FCGI_BEGIN_REQUEST:
			content = chr(self.role>>8) + chr(self.role & 255) + chr(self.flags) + 5*'\000'

		elif self.recType == FCGI_UNKNOWN_TYPE:
			content = chr(self.unknownType) + 7*'\000'

		elif self.recType==FCGI_GET_VALUES or self.recType==FCGI_PARAMS:
			content = ""
			for i in self.values.keys():
				content = content + writePair(i, self.values[i])

		elif self.recType==FCGI_END_REQUEST:
			v = self.appStatus
			content = chr((v>>24)&255) + chr((v>>16)&255) + chr((v>>8)&255) + chr(v&255)
			content = content + chr(self.protocolStatus) + 3*'\000'

		cLen = len(content)
		eLen = (cLen + 7) & (0xFFFF - 7) # align to an 8-byte boundary
		padLen = eLen - cLen

		hdr = [ self.version,
				self.recType,
				self.reqId >> 8,
				self.reqId & 255,
				cLen >> 8,
				cLen & 255,
				padLen,
				0]
		hdr = ''.join(map(chr, hdr))

		sock.send(hdr + content + padLen*'\000')

#---------------------------------------------------------------------------

def readPair(s, pos):
	nameLen = ord(s[pos])
	pos = pos + 1
	if nameLen & 128:
		b = map(ord, s[pos:pos+3])
		pos = pos + 3
		nameLen = ((nameLen&127)<<24) + (b[0]<<16) + (b[1]<<8) + b[2]
	valueLen = ord(s[pos])
	pos = pos + 1
	if valueLen & 128:
		b = map(ord, s[pos:pos+3]) ; pos=pos+3
		valueLen = ((valueLen&127)<<24) + (b[0]<<16) + (b[1]<<8) + b[2]
	return (s[pos:pos+nameLen], s[pos+nameLen:pos+nameLen+valueLen],
		pos+nameLen+valueLen)

#---------------------------------------------------------------------------

def writePair(name, value):
	l = len(name)
	if l < 128:
		s = chr(l)
	else:
		s = chr(128|(l>>24)&255) + chr((l>>16)&255) + chr((l>>8)&255) + chr(l&255)
	l=len(value)
	if l < 128:
		s = s + chr(l)
	else:
		s = s + chr(128|(l>>24)&255) + chr((l>>16)&255) + chr((l>>8)&255) + chr(l&255)
	return s + name + value

#---------------------------------------------------------------------------

def HandleManTypes(r, conn):
	if r.recType == FCGI_GET_VALUES:
		r.recType = FCGI_GET_VALUES_RESULT
		v = {}
		vars={'FCGI_MAX_CONNS' : FCGI_MAX_CONNS,
			  'FCGI_MAX_REQS'  : FCGI_MAX_REQS,
			  'FCGI_MPXS_CONNS': FCGI_MPXS_CONNS}
		for i in r.values.keys():
			if vars.has_key(i):
				v[i] = vars[i]
		r.values = vars
		r.writeRecord(conn)

#---------------------------------------------------------------------------
#---------------------------------------------------------------------------

_isFCGI = 1 # assume it is until we find out for sure

def isFCGI():
	global _isFCGI
	return _isFCGI

#---------------------------------------------------------------------------


_init = None
_sock = None

class FCGI:
	def __init__(self):
		self.haveFinished = 0
		if _init == None:
			_startup()
		if not isFCGI():
			self.haveFinished = 1
			self.inp, self.out, self.err, self.env = \
				sys.stdin, sys.stdout, sys.stderr, os.environ
			return

		if os.environ.has_key('FCGI_WEB_SERVER_ADDRS'):
			good_addrs = os.environ['FCGI_WEB_SERVER_ADDRS'].split(',')
			good_addrs = map(good_addrs.strip()) # remove whitespace
		else:
			good_addrs = None

		self.conn, addr = _sock.accept()
		stdin, data = "", ""
		self.env = {}
		self.requestId = 0
		remaining = 1

		# Check if the connection is from a legal address
		if good_addrs != None and addr not in good_addrs:
			raise error, 'Connection from invalid server!'

		while remaining:
			r = record()
			r.readRecord(self.conn)

			if r.recType in ManagementTypes:
				HandleManTypes(r, self.conn)

			elif r.reqId == 0:
				# Oh, poopy. It's a management record of an unknown type.
				# Signal the error.
				r2=record()
				r2.recType = FCGI_UNKNOWN_TYPE ; r2.unknownType=r.recType
				r2.writeRecord(self.conn)
				continue # charge onwards

			# Ignore requests that aren't active
			elif r.reqId != self.requestId and r.recType != FCGI_BEGIN_REQUEST:
				continue

			# If we're already doing a request, ignore further BEGIN_REQUESTs
			elif r.recType == FCGI_BEGIN_REQUEST and self.requestId != 0:
				continue

			# Begin a new request
			if r.recType == FCGI_BEGIN_REQUEST:
				self.requestId = r.reqId
				if r.role == FCGI_AUTHORIZER:   remaining=1
				elif r.role == FCGI_RESPONDER:  remaining=2
				elif r.role == FCGI_FILTER:     remaining=3

			elif r.recType == FCGI_PARAMS:
				if r.content == "":
					remaining = remaining-1
				else:
					for i in r.values.keys():
						self.env[i] = r.values[i]

			elif r.recType == FCGI_STDIN:
				if r.content == "":
					remaining = remaining-1
				else:
					stdin = stdin + r.content

			elif r.recType==FCGI_DATA:
				if r.content == "":
					remaining = remaining - 1
				else:
					data = data + r.content
		# end of while remaining:

		self.inp = sys.stdin  = StringIO(stdin)
		self.err = sys.stderr = StringIO()
		self.out = sys.stdout = StringIO()
		self.data = StringIO(data)

	def __del__(self):
		self.Finish()

	def Finish(self, status=0):
		if not self.haveFinished:
			self.haveFinished = 1

			self.err.seek(0, 0)
			self.out.seek(0, 0)

			r=record()
			r.recType = FCGI_STDERR
			r.reqId = self.requestId
			data = self.err.read()
			while data:
				chunk, data = self.getNextChunk(data)
				r.content = chunk
				r.writeRecord(self.conn)
			r.content = ""
			r.writeRecord(self.conn) # Terminate stream

			r.recType = FCGI_STDOUT
			data = self.out.read()
			while data:
				chunk, data = self.getNextChunk(data)
				r.content = chunk
				r.writeRecord(self.conn)
			r.content = ""
			r.writeRecord(self.conn) # Terminate stream

			r = record()
			r.recType = FCGI_END_REQUEST
			r.reqId = self.requestId
			r.appStatus = status
			r.protocolStatus = FCGI_REQUEST_COMPLETE
			r.writeRecord(self.conn)
			self.conn.close()


	def getFieldStorage(self):
		method = 'GET'
		if self.env.has_key('REQUEST_METHOD'):
			method = self.env['REQUEST_METHOD'].upper()
		if method == 'GET':
			return cgi.FieldStorage(environ=self.env, keep_blank_values=1)
		else:
			return cgi.FieldStorage(fp=self.inp, environ=self.env, keep_blank_values=1)

	def getNextChunk(self, data):
		chunk = data[:8192]
		data = data[8192:]
		return chunk, data


Accept = FCGI       # alias for backwards compatibility
#---------------------------------------------------------------------------

def _startup():
	global _init
	_init = 1
	try:
		s=socket.fromfd(sys.stdin.fileno(), socket.AF_INET,
						socket.SOCK_STREAM)
		s.getpeername()
	except socket.error, (err, errmsg):
		if err!=errno.ENOTCONN:       # must be a non-fastCGI environment
			global _isFCGI
			_isFCGI = 0
			return

	global _sock
	_sock = s

#---------------------------------------------------------------------------

def _test():
	counter=0
	try:
		while isFCGI():
			req = Accept()
			counter = counter + 1

			try:
				fs = req.getFieldStorage()
				size = int(fs['size'].value)
				doc = ['*' * size]
			except:
				doc = ['<HTML><HEAD><TITLE>FCGI TestApp</TITLE></HEAD>\n<BODY>\n']
				doc.append('<H2>FCGI TestApp</H2><P>')
				doc.append('<b>request count</b> = %d<br>' % counter)
				doc.append('<b>pid</b> = %s<br>' % os.getpid())
				if req.env.has_key('CONTENT_LENGTH'):
					cl = int(req.env['CONTENT_LENGTH'])
					doc.append('<br><b>POST data (%d):</b><br><pre>' % cl)
					keys = fs.keys()
					keys.sort()
					for k in keys:
						val = fs[k]
						if type(val) == type([]):
							doc.append('    <b>%-15s :</b>  %s\n' % (k, val))
						else:
							doc.append('    <b>%-15s :</b>  %s\n' % (k, val.value))
					doc.append('</pre>')

				doc.append('<P><HR><P><pre>')
				keys = req.env.keys()
				keys.sort()
				for k in keys:
					doc.append('<b>%-20s :</b>  %s\n' % (k, req.env[k]))
				doc.append('\n</pre><P><HR>\n')
				doc.append('</BODY></HTML>\n')

			doc = ''.join(doc)
			req.out.write('Content-length: %s\r\n'
						'Content-type: text/html\r\n'
						'Cache-Control: no-cache\r\n'
						'\r\n'
							% len(doc))
			req.out.write(doc)

			req.Finish()
	except:
		import traceback
		f = open('traceback', 'w')
		traceback.print_exc(file = f)
		#  f.write('%s' % doc)

if __name__=='__main__':
	#import pdb
	#pdb.run('_test()')
	_test()
