zeroinstall/injector/_download_child.py

   1 # Copyright (C) 2011, Thomas Leonard
   2 # See the README file for details, or visit http://0install.net.
   3
   4 import sys, os, socket, ssl
   5
   6 from zeroinstall import _
   7 from zeroinstall.injector import download
   8
   9 import urllib2, httplib
  10
  11 for ca_bundle in ["/etc/ssl/certs/ca-certificates.crt", # Debian/Ubuntu/Arch Linux
  12                   "/etc/pki/tls/certs/ca-bundle.crt",   # Fedora/RHEL
  13                   "/etc/ssl/ca-bundle.pem",             # openSUSE/SLE (claimed)
  14                   "/var/lib/ca-certificates/ca-bundle.pem.new"]: # openSUSE (actual)
  15         if os.path.exists(ca_bundle):
  16                 class ValidatingHTTPSConnection(httplib.HTTPSConnection):
  17                         def connect(self):
  18                                 sock = socket.create_connection((self.host, self.port), self.timeout)
  19                                 if self._tunnel_host:
  20                                         self.sock = sock
  21                                         self._tunnel()
  22                                 self.sock = ssl.wrap_socket(sock, cert_reqs = ssl.CERT_REQUIRED, ca_certs = ca_bundle)
  23
  24                 class ValidatingHTTPSHandler(urllib2.HTTPSHandler):
  25                         def https_open(self, req):
  26                                 return self.do_open(self.getConnection, req)
  27
  28                         def getConnection(self, host, timeout=300):
  29                                 return ValidatingHTTPSConnection(host)
  30                 MyHTTPSHandler = ValidatingHTTPSHandler
  31                 break
  32 else:
  33         from logging import warn
  34         warn("No root CA's found; security of HTTPS connections cannot be verified")
  35         MyHTTPSHandler = urllib2.HTTPSHandler
  36
  37 class Redirect(Exception):
  38         def __init__(self, req):
  39                 Exception.__init__(self, "Redirect")
  40                 self.req = req
  41
  42 class MyRedirectHandler(urllib2.HTTPRedirectHandler):
  43         """Throw an exception on redirects instead of continuing. The redirect will be handled in the main thread
  44         so it can work with connection pooling."""
  45         def redirect_request(self, req, fp, code, msg, headers, newurl):
  46                 new_req = urllib2.HTTPRedirectHandler.redirect_request(self, req, fp, code, msg, headers, newurl)
  47                 if new_req:
  48                         raise Redirect(new_req)
  49
  50 # Our handler differs from the Python default in that:
  51 # - we don't support file:// URLs
  52 # - we don't follow HTTP redirects
  53 _my_urlopen = urllib2.OpenerDirector()
  54 for klass in [urllib2.ProxyHandler, urllib2.UnknownHandler, urllib2.HTTPHandler,
  55                        urllib2.HTTPDefaultErrorHandler, MyRedirectHandler,
  56                        urllib2.FTPHandler, urllib2.HTTPErrorProcessor, MyHTTPSHandler]:
  57         _my_urlopen.add_handler(klass())
  58
  59 def download_in_thread(url, target_file, if_modified_since, notify_done):
  60         try:
  61                 #print "Child downloading", url
  62                 if url.startswith('http:') or url.startswith('https:') or url.startswith('ftp:'):
  63                         req = urllib2.Request(url)
  64                         if url.startswith('http:') and if_modified_since:
  65                                 req.add_header('If-Modified-Since', if_modified_since)
  66                         src = _my_urlopen.open(req)
  67                 else:
  68                         raise Exception(_('Unsupported URL protocol in: %s') % url)
  69
  70                 try:
  71                         sock = src.fp._sock
  72                 except AttributeError:
  73                         sock = src.fp.fp._sock  # Python 2.5 on FreeBSD
  74                 while True:
  75                         data = sock.recv(256)
  76                         if not data: break
  77                         target_file.write(data)
  78                         target_file.flush()
  79
  80                 notify_done(download.RESULT_OK)
  81         except (urllib2.HTTPError, urllib2.URLError, httplib.HTTPException, socket.error) as ex:
  82                 if isinstance(ex, urllib2.HTTPError) and ex.code == 304: # Not modified
  83                         notify_done(download.RESULT_NOT_MODIFIED)
  84                 else:
  85                         #print >>sys.stderr, "Error downloading '" + url + "': " + (str(ex) or str(ex.__class__.__name__))
  86                         __, ex, tb = sys.exc_info()
  87                         notify_done(download.RESULT_FAILED, (download.DownloadError(_('Error downloading {url}: {ex}').format(url = url, ex = ex)), tb))
  88         except Redirect as ex:
  89                 notify_done(download.RESULT_REDIRECT, redirect = ex.req.get_full_url())
  90         except Exception as ex:
  91                 __, ex, tb = sys.exc_info()
  92                 notify_done(download.RESULT_FAILED, (ex, tb))