Lib/socket.py

   1 # Wrapper module for _socket, providing some additional facilities
   2 # implemented in Python.
   3
   4 """\
   5 This module provides socket operations and some related functions.
   6 On Unix, it supports IP (Internet Protocol) and Unix domain sockets.
   7 On other systems, it only supports IP.
   8
   9 Functions:
  10
  11 socket() -- create a new socket object
  12 fromfd() -- create a socket object from an open file descriptor [*]
  13 gethostname() -- return the current hostname
  14 gethostbyname() -- map a hostname to its IP number
  15 gethostbyaddr() -- map an IP number or hostname to DNS info
  16 getservbyname() -- map a service name and a protocol name to a port number
  17 getprotobyname() -- mape a protocol name (e.g. 'tcp') to a number
  18 ntohs(), ntohl() -- convert 16, 32 bit int from network to host byte order
  19 htons(), htonl() -- convert 16, 32 bit int from host to network byte order
  20 inet_aton() -- convert IP addr string (123.45.67.89) to 32-bit packed format
  21 inet_ntoa() -- convert 32-bit packed format IP to string (123.45.67.89)
  22 ssl() -- secure socket layer support (only available if configured)
  23
  24  [*] not available on all platforms!
  25
  26 Special objects:
  27
  28 SocketType -- type object for socket objects
  29 error -- exception raised for I/O errors
  30
  31 Integer constants:
  32
  33 AF_INET, AF_UNIX -- socket domains (first argument to socket() call)
  34 SOCK_STREAM, SOCK_DGRAM, SOCK_RAW -- socket types (second argument)
  35
  36 Many other constants may be defined; these may be used in calls to
  37 the setsockopt() and getsockopt() methods.
  38 """
  39
  40 from _socket import *
  41
  42 import os, sys
  43
  44 if (sys.platform.lower().startswith("win")
  45     or (hasattr(os, 'uname') and os.uname()[0] == "BeOS")):
  46
  47     # be sure this happens only once, even in the face of reload():
  48     try:
  49         _realsocketcall
  50     except NameError:
  51         _realsocketcall = socket
  52
  53     def socket(family, type, proto=0):
  54         return _socketobject(_realsocketcall(family, type, proto))
  55
  56
  57 # WSA error codes
  58 if sys.platform.lower().startswith("win"):
  59     errorTab = {}
  60     errorTab[10004] = "The operation was interrupted."
  61     errorTab[10009] = "A bad file handle was passed."
  62     errorTab[10013] = "Permission denied."
  63     errorTab[10014] = "A fault occurred on the network??" # WSAEFAULT
  64     errorTab[10022] = "An invalid operation was attempted."
  65     errorTab[10035] = "The socket operation would block"
  66     errorTab[10036] = "A blocking operation is already in progress."
  67     errorTab[10048] = "The network address is in use."
  68     errorTab[10054] = "The connection has been reset."
  69     errorTab[10058] = "The network has been shut down."
  70     errorTab[10060] = "The operation timed out."
  71     errorTab[10061] = "Connection refused."
  72     errorTab[10063] = "The name is too long."
  73     errorTab[10064] = "The host is down."
  74     errorTab[10065] = "The host is unreachable."
  75 del os, sys
  76
  77
  78 def getfqdn(name=''):
  79     """Get fully qualified domain name from name.
  80
  81     An empty argument is interpreted as meaning the local host.
  82
  83     First the hostname returned by gethostbyaddr() is checked, then
  84     possibly existing aliases. In case no FQDN is available, hostname
  85     is returned.
  86     """
  87     name = name.strip()
  88     if not name or name == '0.0.0.0':
  89         name = gethostname()
  90     try:
  91         hostname, aliases, ipaddrs = gethostbyaddr(name)
  92     except error:
  93         pass
  94     else:
  95         aliases.insert(0, hostname)
  96         for name in aliases:
  97             if '.' in name:
  98                 break
  99         else:
 100             name = hostname
 101     return name
 102
 103
 104 #
 105 # These classes are used by the socket() defined on Windows and BeOS
 106 # platforms to provide a best-effort implementation of the cleanup
 107 # semantics needed when sockets can't be dup()ed.
 108 #
 109 # These are not actually used on other platforms.
 110 #
 111
 112 class _socketobject:
 113
 114     def __init__(self, sock):
 115         self._sock = sock
 116
 117     def close(self):
 118         self._sock = 0
 119
 120     def __del__(self):
 121         self.close()
 122
 123     def accept(self):
 124         sock, addr = self._sock.accept()
 125         return _socketobject(sock), addr
 126
 127     def dup(self):
 128         return _socketobject(self._sock)
 129
 130     def makefile(self, mode='r', bufsize=-1):
 131         return _fileobject(self._sock, mode, bufsize)
 132
 133     _s = "def %s(self, *args): return apply(self._sock.%s, args)\n\n"
 134     for _m in ('bind', 'connect', 'connect_ex', 'fileno', 'listen',
 135                'getpeername', 'getsockname',
 136                'getsockopt', 'setsockopt',
 137                'recv', 'recvfrom', 'send', 'sendto',
 138                'setblocking',
 139                'shutdown'):
 140         exec _s % (_m, _m)
 141
 142
 143 class _fileobject:
 144
 145     def __init__(self, sock, mode, bufsize):
 146         self._sock = sock
 147         self._mode = mode
 148         if bufsize < 0:
 149             bufsize = 512
 150         self._rbufsize = max(1, bufsize)
 151         self._wbufsize = bufsize
 152         self._wbuf = self._rbuf = ""
 153
 154     def close(self):
 155         try:
 156             if self._sock:
 157                 self.flush()
 158         finally:
 159             self._sock = 0
 160
 161     def __del__(self):
 162         self.close()
 163
 164     def flush(self):
 165         if self._wbuf:
 166             self._sock.send(self._wbuf)
 167             self._wbuf = ""
 168
 169     def fileno(self):
 170         return self._sock.fileno()
 171
 172     def write(self, data):
 173         self._wbuf = self._wbuf + data
 174         if self._wbufsize == 1:
 175             if '\n' in data:
 176                 self.flush()
 177         else:
 178             if len(self._wbuf) >= self._wbufsize:
 179                 self.flush()
 180
 181     def writelines(self, list):
 182         filter(self._sock.send, list)
 183         self.flush()
 184
 185     def read(self, n=-1):
 186         if n >= 0:
 187             k = len(self._rbuf)
 188             if n <= k:
 189                 data = self._rbuf[:n]
 190                 self._rbuf = self._rbuf[n:]
 191                 return data
 192             n = n - k
 193             L = [self._rbuf]
 194             self._rbuf = ""
 195             while n > 0:
 196                 new = self._sock.recv(max(n, self._rbufsize))
 197                 if not new: break
 198                 k = len(new)
 199                 if k > n:
 200                     L.append(new[:n])
 201                     self._rbuf = new[n:]
 202                     break
 203                 L.append(new)
 204                 n = n - k
 205             return "".join(L)
 206         k = max(512, self._rbufsize)
 207         L = [self._rbuf]
 208         self._rbuf = ""
 209         while 1:
 210             new = self._sock.recv(k)
 211             if not new: break
 212             L.append(new)
 213             k = min(k*2, 1024**2)
 214         return "".join(L)
 215
 216     def readline(self, limit=-1):
 217         data = ""
 218         i = self._rbuf.find('\n')
 219         while i < 0 and not (0 < limit <= len(self._rbuf)):
 220             new = self._sock.recv(self._rbufsize)
 221             if not new: break
 222             i = new.find('\n')
 223             if i >= 0: i = i + len(self._rbuf)
 224             self._rbuf = self._rbuf + new
 225         if i < 0: i = len(self._rbuf)
 226         else: i = i+1
 227         if 0 <= limit < len(self._rbuf): i = limit
 228         data, self._rbuf = self._rbuf[:i], self._rbuf[i:]
 229         return data
 230
 231     def readlines(self, sizehint = 0):
 232         total = 0
 233         list = []
 234         while 1:
 235             line = self.readline()
 236             if not line: break
 237             list.append(line)
 238             total += len(line)
 239             if sizehint and total >= sizehint:
 240                 break
 241         return list