[Python-Dev] More socket questions (original) (raw)

Mihai Ibanescu misa@redhat.com
Thu, 10 Apr 2003 15:29:20 -0400 (EDT)

Hello,

Since somebody mention inet_addr, here's something else that I can attempt to fix if we agree on it.

In python 2.2.2:

socket.inet_aton("255.255.255.255") Traceback (most recent call last): File "", line 1, in ? socket.error: illegal IP address string passed to inet_aton

Implementation:

static PyObject* PySocket_inet_aton(PyObject *self, PyObject *args) { #ifndef INADDR_NONE #define INADDR_NONE (-1) #endif

    /* Have to use inet_addr() instead */
    char *ip_addr;
    unsigned long packed_addr;

    if (!PyArg_ParseTuple(args, "s:inet_aton", &ip_addr)) {
            return NULL;
    }

#ifdef USE_GUSI1 packed_addr = inet_addr(ip_addr).s_addr; #else packed_addr = inet_addr(ip_addr); #endif

    if (packed_addr == INADDR_NONE) {       /* invalid address */
            PyErr_SetString(PySocket_Error,
                    "illegal IP address string passed to inet_aton");

Reason for this behaviour can be found in the man page for inet_addr:

   The  inet_addr()  function  converts  the  Internet   host
   address cp from numbers-and-dots notation into binary data
   in  network  byte  order.   If  the  input   is   invalid,
   INADDR_NONE (usually -1) is returned.  This is an obsolete
   interface to inet_aton, described immediately above; it is
   obsolete  because -1 is a valid address (255.255.255.255),
   and inet_aton provides a cleaner  way  to  indicate  error
   return.

I propose that we use inet_aton to implement PySocket_inet_aton (am I clever or what). The part that I don't know, how portable is this function? Does it exist on Mac and Windows?

Thanks, Misa