apt_dht/HTTPServer.py

   1
   2 from urllib import unquote_plus
   3 from binascii import b2a_hex
   4
   5 from twisted.python import log
   6 from twisted.internet import defer
   7 from twisted.web2 import server, http, resource, channel, stream
   8 from twisted.web2 import static, http_headers, responsecode
   9
  10 from policies import ThrottlingFactory
  11 from apt_dht_Khashmir.bencode import bencode
  12
  13 class FileDownloader(static.File):
  14
  15     def __init__(self, path, manager, defaultType="text/plain", ignoredExts=(), processors=None, indexNames=None):
  16         self.manager = manager
  17         super(FileDownloader, self).__init__(path, defaultType, ignoredExts, processors, indexNames)
  18
  19     def renderHTTP(self, req):
  20         log.msg('Got request for %s from %s' % (req.uri, req.remoteAddr))
  21         resp = super(FileDownloader, self).renderHTTP(req)
  22         if isinstance(resp, defer.Deferred):
  23             resp.addCallback(self._renderHTTP_done, req)
  24         else:
  25             resp = self._renderHTTP_done(resp, req)
  26         return resp
  27
  28     def _renderHTTP_done(self, resp, req):
  29         log.msg('Initial response to %s: %r' % (req.uri, resp))
  30
  31         if self.manager:
  32             path = 'http:/' + req.uri
  33             if resp.code >= 200 and resp.code < 400:
  34                 return self.manager.check_freshness(req, path, resp.headers.getHeader('Last-Modified'), resp)
  35
  36             log.msg('Not found, trying other methods for %s' % req.uri)
  37             return self.manager.get_resp(req, path)
  38
  39         return resp
  40
  41     def createSimilarFile(self, path):
  42         return self.__class__(path, self.manager, self.defaultType, self.ignoredExts,
  43                               self.processors, self.indexNames[:])
  44
  45 class FileUploaderStream(stream.FileStream):
  46
  47     CHUNK_SIZE = 4*1024
  48
  49     def read(self, sendfile=False):
  50         if self.f is None:
  51             return None
  52
  53         length = self.length
  54         if length == 0:
  55             self.f = None
  56             return None
  57
  58         readSize = min(length, self.CHUNK_SIZE)
  59
  60         self.f.seek(self.start)
  61         b = self.f.read(readSize)
  62         bytesRead = len(b)
  63         if not bytesRead:
  64             raise RuntimeError("Ran out of data reading file %r, expected %d more bytes" % (self.f, length))
  65         else:
  66             self.length -= bytesRead
  67             self.start += bytesRead
  68             return b
  69
  70
  71 class FileUploader(static.File):
  72
  73     def render(self, req):
  74         if not self.fp.exists():
  75             return responsecode.NOT_FOUND
  76
  77         if self.fp.isdir():
  78             return responsecode.NOT_FOUND
  79
  80         try:
  81             f = self.fp.open()
  82         except IOError, e:
  83             import errno
  84             if e[0] == errno.EACCES:
  85                 return responsecode.FORBIDDEN
  86             elif e[0] == errno.ENOENT:
  87                 return responsecode.NOT_FOUND
  88             else:
  89                 raise
  90
  91         response = http.Response()
  92         response.stream = FileUploaderStream(f, 0, self.fp.getsize())
  93
  94         for (header, value) in (
  95             ("content-type", self.contentType()),
  96             ("content-encoding", self.contentEncoding()),
  97         ):
  98             if value is not None:
  99                 response.headers.setHeader(header, value)
 100
 101         return response
 102
 103 class TopLevel(resource.Resource):
 104     addSlash = True
 105
 106     def __init__(self, directory, db, manager):
 107         self.directory = directory
 108         self.db = db
 109         self.manager = manager
 110         self.factory = None
 111
 112     def getHTTPFactory(self):
 113         if self.factory is None:
 114             self.factory = channel.HTTPFactory(server.Site(self),
 115                                                **{'maxPipeline': 10,
 116                                                   'betweenRequestsTimeOut': 60})
 117             self.factory = ThrottlingFactory(self.factory, writeLimit = 30*1024)
 118         return self.factory
 119
 120     def render(self, ctx):
 121         return http.Response(
 122             200,
 123             {'content-type': http_headers.MimeType('text', 'html')},
 124             """<html><body>
 125             <h2>Statistics</h2>
 126             <p>TODO: eventually some stats will be shown here.</body></html>""")
 127
 128     def locateChild(self, request, segments):
 129         log.msg('Got HTTP request for %s from %s' % (request.uri, request.remoteAddr))
 130         name = segments[0]
 131         if name == '~':
 132             if len(segments) != 2:
 133                 log.msg('Got a malformed request from %s' % request.remoteAddr)
 134                 return None, ()
 135             hash = unquote_plus(segments[1])
 136             files = self.db.lookupHash(hash)
 137             if files:
 138                 if 'path' in files[0]:
 139                     log.msg('Sharing %s with %s' % (files[0]['path'].path, request.remoteAddr))
 140                     return FileUploader(files[0]['path'].path), ()
 141                 else:
 142                     log.msg('Sending torrent string %s to %s' % (b2a_hex(hash), request.remoteAddr))
 143                     return static.Data(bencode({'t': files[0]['pieces']}), 'application/x-bencoded'), ()
 144             else:
 145                 log.msg('Hash could not be found in database: %s' % hash)
 146
 147         if request.remoteAddr.host != "127.0.0.1":
 148             log.msg('Blocked illegal access to %s from %s' % (request.uri, request.remoteAddr))
 149             return None, ()
 150
 151         if len(name) > 1:
 152             return FileDownloader(self.directory.path, self.manager), segments[0:]
 153         else:
 154             return self, ()
 155
 156         log.msg('Got a malformed request for "%s" from %s' % (request.uri, request.remoteAddr))
 157         return None, ()
 158
 159 if __name__ == '__builtin__':
 160     # Running from twistd -ny HTTPServer.py
 161     # Then test with:
 162     #   wget -S 'http://localhost:18080/~/whatever'
 163     #   wget -S 'http://localhost:18080/~/pieces'
 164
 165     import os.path
 166     from twisted.python.filepath import FilePath
 167
 168     class DB:
 169         def lookupHash(self, hash):
 170             if hash == 'pieces':
 171                 return [{'pieces': 'abcdefghij0123456789\xca\xec\xb8\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'}]
 172             return [{'path': FilePath(os.path.expanduser('~/school/optout'))}]
 173
 174     t = TopLevel(FilePath(os.path.expanduser('~')), DB(), None)
 175     factory = t.getHTTPFactory()
 176
 177     # Standard twisted application Boilerplate
 178     from twisted.application import service, strports
 179     application = service.Application("demoserver")
 180     s = strports.service('tcp:18080', factory)
 181     s.setServiceParent(application)