python/rox/suchild.py

   1 """This is the child program run by the su module. Do not import this module."""
   2 import os, sys
   3 import cPickle as pickle
   4 import time
   5 import shutil
   6
   7 import proxy
   8
   9 read_watches = []
  10 write_watches = []
  11
  12 class Watch:
  13         """Contains a file descriptor and a function to call when it's ready"""
  14         def __init__(self, fd, fn):
  15                 self.fd = fd
  16                 self.ready = fn
  17
  18         def fileno(self):
  19                 return self.fd
  20
  21 class SuSlave(proxy.SlaveProxy):
  22         """A simple implementation of SlaveProxy that doesn't use gtk"""
  23         def __init__(self, to_parent, from_parent, slave):
  24                 self.read_watch = Watch(from_parent, self.read_ready)
  25                 self.write_watch = Watch(to_parent, self.write_ready)
  26                 proxy.SlaveProxy.__init__(self, to_parent, from_parent, slave)
  27
  28         def enable_read_watch(self):
  29                 assert self.read_watch not in read_watches
  30                 read_watches.append(self.read_watch)
  31
  32         def enable_write_watch(self):
  33                 assert self.write_watch not in write_watches
  34                 write_watches.append(self.write_watch)
  35
  36 class Slave:
  37         """This object runs as another user. Most methods behave in a similar
  38         way to the standard python methods of the same name."""
  39
  40         def spawnvpe(self, request, mode, file, args, env = None):
  41                 if env is None:
  42                         request.send(os.spawnvp(mode, file, args))
  43                 else:
  44                         request.send(os.spawnvpe(mode, file, args, env))
  45
  46         def waitpid(self, request, pid, flags):
  47                 request.send(os.waitpid(pid, flags))
  48
  49         def getuid(self, request):
  50                 request.send(os.getuid())
  51
  52         def setuid(self, request, uid):
  53                 request.send(os.setuid(uid))
  54
  55         def rmtree(self, request, path):
  56                 shutil.rmtree(path)
  57                 request.send(None)
  58
  59 if __name__ == '__main__':
  60         from select import select
  61
  62         to_parent, from_parent = map(int, sys.argv[1:])
  63
  64         sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(sys.argv[0]))))
  65
  66         slave_proxy = SuSlave(to_parent, from_parent, Slave())
  67
  68         while read_watches or write_watches:
  69                 readable, writable = select(read_watches, write_watches, [])[:2]
  70                 for w in readable:
  71                         if not w.ready():
  72                                 read_watches.remove(w)
  73                 for w in writable:
  74                         if not w.ready():
  75                                 write_watches.remove(w)