palm/lib/child.py

   1 # Copyright (C) 2008-2009, Eduardo Silva <edsiper@gmail.com>
   2 #
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program; if not, write to the Free Software
  15 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  16
  17 import os
  18 import sys
  19 import time
  20 import signal
  21 import fcntl
  22 from debug import *
  23
  24 class Child:
  25     def __init__(self, name, socket, parent):
  26         # Listener socket
  27         self.name = name
  28         self._s = socket
  29
  30         # Parent Object
  31         self.parent = parent
  32         self.split_conf()
  33
  34         # On child end, re-create it
  35         signal.signal(signal.SIGCHLD, self._child_exit)
  36
  37         # Start our child
  38         self._create()
  39
  40     def split_conf(self):
  41         try:
  42             opts = self.parent.opts.split()
  43         except:
  44             opts = []
  45
  46         self.c = {'bin': self.parent.bin, 'opts': opts}
  47
  48     def _create(self):
  49         # Fork process
  50         pid = os.fork()
  51         if pid:
  52             self._pid = pid
  53             msg = "    Creating '%s' child PID %i" % (self.name, pid)
  54             debug(msg)
  55         else:
  56             # Start child loop
  57             self.start_loop()
  58
  59     def _child_exit(self,a, b):
  60         os.wait()
  61         debug("[-] Exit child '%s'" % self.name)
  62         self._create()
  63
  64     def read(self, fd):
  65         buf = ""
  66         while 1:
  67             data = fd.recv(4096)
  68             if len(data) == 0:
  69                 break
  70             else:
  71                 buf += data
  72                 if buf[-4:] == '\r\n\r\n':
  73                     break;
  74
  75         return buf
  76
  77     def parse_request(self, data):
  78         arr = data.split('\r\n')
  79         request = None
  80
  81         for line in arr[:-2]:
  82             # print line
  83             if line == arr[0]:
  84                 request = Request(line)
  85                 continue
  86
  87             sep = line.find('=')
  88             if sep < 0:
  89                 continue
  90
  91             key = line[:sep]
  92             val = line[sep+1:]
  93
  94             if key == 'POST_VARS' and len(val) > 0:
  95                 val = '*'
  96
  97             # Register key value
  98             request.add_header(key, val)
  99
 100
 101         # Post-parse POST data
 102         if request.get('POST_VARS') == '*':
 103             init_key = '\r\nPOST_VARS='
 104             len_key = len(init_key)
 105
 106             post_len = int(request.get('CONTENT_LENGTH'))
 107             post_data = data.find(init_key)
 108
 109             # Set string offsets
 110             offset_init = post_data + len_key
 111             offset_end = post_data + len_key + post_len
 112
 113             # Override POST_VARS
 114             request.add_header('POST_VARS', data[offset_init:offset_end])
 115
 116         if request is None:
 117             debug("[+] Invalid Exit")
 118             exit(1)
 119
 120         # Debug message
 121         msg = "[+] Request Headers\n"
 122         for h in request.headers:
 123             msg += '    ' + h + ' = \'' + request.headers[h] + '\'\n'
 124         msg += "[-] Request End"
 125         debug(msg)
 126
 127         return request
 128
 129     def start_loop(self):
 130         # Creating epoll for read pipe side
 131         while 1:
 132             remote, info = self._s.accept()
 133             remote_fd = remote.fileno()
 134
 135             # Close on exec
 136             flags = fcntl.fcntl(remote_fd, fcntl.F_GETFD)
 137             try:
 138                 flags |= fcntl.FD_CLOEXEC
 139             except AttributeError, e:
 140                 flags |= 1
 141
 142             fcntl.fcntl(remote_fd, fcntl.F_SETFD, flags)
 143
 144             debug("[+] |%s| Request arrived [PID=%i]" % (self.name, os.getpid()))
 145
 146             buf = self.read(remote)
 147             print buf
 148             request = self.parse_request(buf)
 149
 150             if self.c['bin'] is None:
 151                 bin = request.resource
 152             else:
 153                 bin = self.c['bin']
 154
 155             if self.c['opts'] is None and bin != request.resource:
 156                 opts = [request.resource]
 157             else:
 158                 opts = self.c['opts']
 159                 opts.append(request.resource)
 160
 161             print "***"
 162             print request.headers['POST_VARS']
 163             print "***"
 164             try:
 165                 os.dup2(remote.fileno(), sys.stdout.fileno())
 166
 167                 # Write Post data to STDIN (Pipe)
 168                 if request.headers['REQUEST_METHOD'] == 'POST':
 169                     # Temporal Pipe > STDIN
 170                     pipe_r, pipe_w = os.pipe()
 171                     os.dup2(pipe_r, sys.stdin.fileno())
 172                     os.write(pipe_w, request.headers['POST_VARS'])
 173
 174                 os.execve(bin, opts, request.headers)
 175             except:
 176                 print "Content-Type: text/plain\r\n\r\n"
 177
 178                 print "*** INTERNAL ERROR ***"
 179                 print
 180
 181                 print "Child Executing"
 182                 print "---------------"
 183                 print bin, opts
 184
 185                 print
 186                 print "Palm Enviroment variables"
 187                 print "-------------------------"
 188                 for h in request.headers:
 189                     print h, "=", request.headers[h]
 190
 191                 exit(1)
 192
 193     def get_pid(self):
 194         return self._pid
 195
 196     def kill(self):
 197         os.kill(self._pid, signal.SIGKILL)
 198
 199 class Request:
 200     def __init__(self, resource):
 201         self.resource = resource
 202         self.headers = {}
 203
 204     def __str__(self):
 205         ret = str(self.resource) + ' ' + str(self.headers);
 206         return ret
 207
 208     def add_header(self, key, val):
 209         self.headers[key] = val
 210
 211     def get(self, key):
 212         return self.headers[key]