files/usr/bin/sipb-xen-consolefs

   1 #!/usr/bin/python
   2
   3 import fuse
   4 from fuse import Fuse
   5
   6 from time import time
   7
   8 import stat     # for file properties
   9 import os         # for filesystem modes (O_RDONLY, etc)
  10 import errno   # for error number codes (ENOENT, etc)
  11                            # - note: these must be returned as negatives
  12
  13 import sipb_xen_database
  14
  15 fuse.fuse_python_api = (0, 2)
  16
  17 realpath = "/home/machines/"
  18
  19 def dirFromList(list):
  20         """
  21         Return a properly formatted list of items suitable to a directory listing.
  22         ['a', 'b', 'c'] => [('a', 0), ('b', 0), ('c', 0)]
  23         """
  24         return [(x, 0) for x in list]
  25
  26 def getDepth(path):
  27         """
  28         Return the depth of a given path, zero-based from root ('/')
  29         """
  30         if path == '/':
  31                 return 0
  32         else:
  33                 return path.count('/')
  34
  35 def getParts(path):
  36         """
  37         Return the slash-separated parts of a given path as a list
  38         """
  39         if path == '/':
  40                 return ['/']
  41         else:
  42                 return path[1:].split('/')
  43
  44 class MyStat:
  45         def __init__(self):
  46                 self.st_mode = 0
  47                 self.st_ino = 0
  48                 self.st_dev = 0
  49                 self.st_nlink = 0
  50                 self.st_uid = 0
  51                 self.st_gid = 0
  52                 self.st_size = 0
  53                 self.st_atime = 0
  54                 self.st_mtime = 0
  55                 self.st_ctime = 0
  56
  57         def toTuple(self):
  58                 return (self.st_mode, self.st_ino, self.st_dev, self.st_nlink, self.st_uid, self.st_gid, self.st_size, self.st_atime, self.st_mtime, self.st_ctime)
  59
  60 class ConsoleFS(Fuse):
  61         """
  62         """
  63
  64         def __init__(self, *args, **kw):
  65                 Fuse.__init__(self, *args, **kw)
  66                 self.lasttime = time()
  67                 self.allow_other = 1
  68                 print 'Init complete.'
  69
  70         def mirrorPath(self, path):
  71                 return realpath + "/".join(getParts(path)[1:])
  72
  73         def getMachines(self):
  74                 if time() - self.lasttime > 15:
  75                         self.lasttime = time()
  76                         sipb_xen_database.clear_cache()
  77                 return [machine.name for machine in sipb_xen_database.Machine.select()]
  78
  79         def getUid(self, machine_name):
  80                 return sipb_xen_database.Machine.get_by(name=machine_name).machine_id + 1000
  81
  82         def getK5login(self, machine_name):
  83                 machine = sipb_xen_database.Machine.get_by(name=machine_name)
  84                 users = [acl.user for acl in machine.acl]
  85                 return "\n".join(map(self.userToPrinc, users) + [''])
  86
  87         def userToPrinc(self, user):
  88                 if '@' in user:
  89                         (princ, realm) = user.split('@')
  90                 else:
  91                         princ = user
  92                         realm = "ATHENA.MIT.EDU"
  93
  94                 return princ.replace('.', '/') + '@' + realm
  95
  96         def getattr(self, path):
  97                 """
  98                 - st_mode (protection bits)
  99                 - st_ino (inode number)
 100                 - st_dev (device)
 101                 - st_nlink (number of hard links)
 102                 - st_uid (user ID of owner)
 103                 - st_gid (group ID of owner)
 104                 - st_size (size of file, in bytes)
 105                 - st_atime (time of most recent access)
 106                 - st_mtime (time of most recent content modification)
 107                 - st_ctime (platform dependent; time of most recent metadata change on Unix,
 108                                         or the time of creation on Windows).
 109                 """
 110
 111                 print "*** getattr: " + path
 112
 113                 depth = getDepth(path)
 114                 parts = getParts(path)
 115
 116                 st = MyStat()
 117                 if path == '/':
 118                         st.st_mode = stat.S_IFDIR | 0755
 119                         st.st_nlink = 2
 120                 elif depth == 1:
 121                         if parts[-1] in self.getMachines():
 122                                 st.st_mode = stat.S_IFDIR | 0755
 123                                 st.st_nlink = 2
 124                                 st.st_uid = st.st_gid = self.getUid(parts[0])
 125                         else:
 126                                 return -errno.ENOENT
 127                 elif depth == 2 and parts[-1] == '.k5login':
 128                         st.st_mode = stat.S_IFREG | 0444
 129                         st.st_nlink = 1
 130                         st.st_size = len(self.getK5login(parts[0]))
 131                         st.st_uid = st.st_gid = self.getUid(parts[0])
 132                 else:
 133                         stats = list(os.lstat(self.mirrorPath(path)))
 134                         stats[4:6] = [self.getUid(parts[0])] * 2
 135                         return tuple(stats)
 136                 return st.toTuple()
 137
 138         def readdir(self, path, offset):
 139                 print '*** readdir', path, offset
 140                 for (value, zero) in self.getdir(path):
 141                         yield fuse.Direntry(value)
 142
 143         def getdir(self, path):
 144                 print '*** getdir', path
 145                 if path == '/':
 146                         contents = ['.', '..']+self.getMachines()
 147                 elif getDepth(path) == 1:
 148                         contents = set(os.listdir(self.mirrorPath(path)) + ['.k5login', '.', '..'])
 149                 else:
 150                         contents = os.listdir(self.mirrorPath(path)) + ['.', '..']
 151                 return [(i, 0) for i in contents]
 152
 153         def read ( self, path, length, offset ):
 154                 print '*** read', path, length, offset
 155
 156                 parts = getParts(path)
 157
 158                 if getDepth(path) < 2:
 159                         return -errno.ENOENT
 160                 elif parts[1:] == ['.k5login']:
 161                         if parts[0] not in self.getMachines():
 162                                 return -errno.ENOENT
 163                         else:
 164                                 return self.getK5login(parts[0])[offset:length + offset]
 165                 else:
 166                         fname = self.mirrorPath(path)
 167                         if not os.path.isfile(fname):
 168                                 return -errno.ENOENT
 169                         else:
 170                                 f = open(fname)
 171                                 f.seek(offset)
 172                                 return f.read(length)
 173
 174 if __name__ == '__main__':
 175         sipb_xen_database.connect('postgres://sipb-xen@sipb-xen-dev.mit.edu/sipb_xen')
 176         usage="""
 177 ConsoleFS [mount_path]
 178 """
 179         server = ConsoleFS()
 180         server.flags = 0
 181         server.main()